激光显示器毕业论文英文翻译

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电子信息工程本科毕业中英文翻译

英语原文：Life of LED-Based White Light SourcesThe interest for using light-emitting diodes (LEDs) for display and illumination applications has been growing steadily over the past few years. The potential for long life and reduced energy use are two key attributes of this rapidly evolving technology that have generated so much interest for its use in the above mentioned applications. Traditionally, the lamp life of light sources commonly used in illumination applications is determined by subjecting them to a predetermined on/off cycle until half the number of light sources cease to produce light. Unlike these sources, LEDs rarely fail catastrophically; instead, their light output slowly degrades over time. Even if an LED is technically operating and producing light, at some point the amount of light produced by the LED will be insufficient for the intended application. Therefore, the life of an LED should be based on the amount of time that the device can produce sufficient light for the intended application,rather than complete failure. Based on this argument, a recent publication from an industry group defines the life of an LED device or system for use in general lighting applications as the operating time, in hours, for the light output to reach 70% of its initial value.The most widely used white LEDs incorporate a layer of phosphor over a GaN-based, short-wavelength light emitter. Usually, the phosphor is embedded inside an epoxy resin that surrounds the LED die. Some portion of the short-wavelength radiation emitted by the LED is down-converted by the phosphor, and the combined radiation creates white light.Early white LEDs were packaged similar to the indicator-style colored LEDs, specifically 5 mm and SMD (surface mount devices). Although these products demonstrated the concept of a white light source, they did not produce sufficient light for display and illumination applications. Furthermore, these indicator-style white LEDs had a relatively short life, 5000–10 000h to reach 70% light level under normal operating conditions. To address the higher luminous flux requirements, manufacturers have started to commercialize high-power illuminator LEDs that are presently producing over one hundred times the flux compared to indicator-style white LEDs. The higher light output isachieved by using larger dies, higher drive currents,and improved heat extraction methods. In addition,some manufacturers are using better encapsulants to improve the life of white LEDs.There are several studies that have investigated the aging mechanisms of GaN-based LEDs. During the 1990s,Barton et al. investigated the degradation of GaN-based blue LEDs and showed that light output reduction over time occurred primarily due to the yellowing of the epoxy surrounding the die. In 2001, Narendran et al. observed that indicator-style white LED packages degraded very rapidly, with the LEDs reaching the 50% light output level within 6000 h. In that same study, it was shown that the chromaticity values of the white LEDs shifted toward yellow over time, and it was speculated that the yellowing of the epoxy was the main cause for light output degradation. Therefore, based on past studies,the primary reason for the degradation of indicator-style white LED packages is the yellowing of the epoxy that is caused by excessive heat at the p-n-junction of the LED. Some of the newer illuminator-style white LEDs use encapsulant materials that have lower photodegradation characteristics,and therefore have a lower degradation rate. However, there are factors such as the degradation of the die attaché epoxy, discoloration of the metal reflectors and the lead wires, and degradation of the semiconducting element that are influenced by heat, and these all contribute to the overall degradation of the white LED. Although the newer high-power white LEDs would have a lower degradation rate compared to the early indicator-style devices, it is the heat at the p-n-junction that most influences the degradation. The heat at the p-n-junction is caused by the ambient temperature and the ohmic heating at the bandgap.As stated earlier, long life is one key feature of LED technology that has attracted so many end-use communities. To benefit from the long-life feature, it is the final system that has to operate for a long time, not just the individual LED. As noted in past studies, heat at the p-n-junction is one of the key factors that determine the life of the white LED. Therefore, if systems are not properly designed with good thermal managemen techniques, even if they use long-life white LEDs the life of the final system would be short. Developing the relationship between junction temperature and life would be very usefulfor producing long-life systems.Although there are different methods available for estimating the junction temperature of LEDs, they are not very convenient,especially once the LEDs are integrated into a system . Furthermore, these methods are not direct; consequently, they are prone to erroneous results. Alternatively, it is much more convenient and direct to measure the heat at a location external to the LED package that is sufficiently close to the junction and where a temperature sensor can be directly attached. The temperature of this point should have a good relationship to the junction temperature. The point where a temperature sensor can be attached for this measurement could be the lead wire (cathode side) for the indicator-style LEDs and the board for high-power LEDs. Most manufacturers can recommend such a point,and we refer to this as the T-point in this manuscript.Since white LEDs in the marketplace are packaged differently, their ability to transfer heat from the die to the surrounding environment is different from product to product. Therefore, it is reasonable to assume that different products have different degradation rates as a function of heat. A graph that shows the life of the LED as a function of T-point temperature is extremely useful for system manufacturers to build reliable, long-lasting systems. By knowing how much impact heat has on the degradation rate or life of the LED, the system manufacturer can select components and drive parameters, including the amount of heat sink and drive current, for a product being designed for a given application.Therefore, the objective of the study presented in this manuscript was to investigate the relationship between the T-point temperature and life of a white LED. A second objective was to understand the degradation rate of different high-power white LED products presently available in the marketplace.To understand the relationship between the T-point temperature and life, one type of high-power white LED that is commonly available in the marketplace was selected. Several of these LEDs were subjected to a life test under different ambient temperatures. The details of the experimental setup are described in the following paragraphs.Because the different LED arrays have to operate at a particular ambient temperature, the arrays were placed inside specially designed, individual life-test chambers. The test chambers had two different functions: 1) to keep the ambient temperature constant for the LED arrays and 2) to act as light-integrating boxes for measuring light output. Each individual LED array was mounted at the center of the inside top surface of a life-test chamber. A photodiode attached to the center of the left panel continuously measured the light output.A small white baffle placed over the photodiode shielded it from the direct light, allowing only the reflected light to reach the photodiode. A resistance temperature detector placed on top of the baffle measured the chamber’s ambient temperature and controlled the heater that provided the necessary heat to the chamber through a temperature controller. The temperature in-side the box remained within ±1℃.The heater was attached to a raised aluminum plate with a matte-white cover that sat on the chamber floor. The temperature was estimated using a J-type thin wire thermocouple soldered to the T-point of white LED. For each chamber, an external LED driver controlled the current flow through the LEDs. All life-test were placed inside a temperature-controlled room. The life-test chambers were staggered vertically and horizontally to ensure that heat rising from the bottom chambers did not affect the chambers above them.The results of this study underscore the importance of packaging white LEDs using proper thermal management to maintain light output, and thereby extend system life. Heat at the p-n-junction is one of the main factors that affect the life of white LEDs. Therefore, knowing the relationship between life and heat would be very useful for manufacturers who are interested in developing reliable, long-lasting systems.Results from the first experiment—conducted under various ambient temperatures to understand the relationship between T-point temperature and life—indicate that life decreases with increasing temperature in an exponential manner. Results from the second experiment—conducted to understand how different commercial white LEDs perform under identical operating conditions—show a large variation in life among the different packages, indicating that the packages used different heat extraction techniques and materials.As part of ongoing research, we hope to further investigate how the different commercial LEDs are affected by heat and finally develop a family of curves that illustrate the relationship between life and T-point temperature for the different products.中文翻译：基于LED的白色光源的寿命在过去几年中利用发光二极管(led)显示和作为照明应用的技术一直在稳步增长。

关于LED的外文文献和中文译文

多个LED发光装置的新型采集系统作为光源的一种，发光二极管（LED）有很多优点。

LED集成度更高，颜色种类多，使用寿命更长，而且工作电压较低。

但是，它仍有一个非常大的缺陷：一只LED的光照强度还是比较低。

这个缺点导致显示屏上的光通量不会很高。

但是无论如何，LED还是以其出色的性能在低电压装置中普遍应用。

因此，利用此系统采集多个LED的光，集成为更高强度的照明装置。

本设计提出三种采集系统，来实现增强光强的功能。

效率最好的一种采集系统可以达到96%。

同时，还分析了本系统的制造误差以及预算。

1 简介利用传统的光源来设计一个便携式探照灯，尺寸和能耗会很大。

而利用LED 来设计将会避免这些问题。

LED有很多优点：节能、体积较小、使用寿命长（约100,103小时）等，尤其是LED的光很适合环境工作。

Carel Zeiss和Philips打算用LED光源设计两种便携式探照灯。

尽管LED有诸多优点，可以让他们设计出的探照灯更加便携和小巧，但是由于光学元件的转换效率问题，导致系统有很多困难。

解决这个困难将是本文研究的重点。

通常，用一种合成非线性集中器（CPC）来减小分散度。

但是，这种传统的CPC采集效率仅为72%，必须要改善采集效率来提高光的利用率。

本文中将解决分散度和采集效率两个问题。

为实现这个目标，设计了三种不同的采集系统，以提高效率，下面逐一介绍。

2 仿真部分利用光学仿真软件和标签查找模块（BRO），来设计并分析采集系统的性能。

LED光源部分来自Osram-Opical半导体。

远程LED光源是一种Lambertian模式，LED的规格见表1。

在采集系统的底部有四个LED。

系统各个LED之间的位置关系如图1。

通光部分为2.1×2.1mm2，孔径3.26mm。

LED阵列对称的分布于系统的底部。

采集系统的第一个光学元件为均质器。

这个均质器的受光角度是12.5°。

因此，这个系统就是要把LED的受光角度的范围控制在±60°到±12.5°之间。

LED英文资料及中文翻译

First LED SummaryLED (Light Emitting Diode), light-emitting diode, is a solid state semiconductor devices, which can be directly converted into electricity to light. LED is the heart of a semiconductor chip, the chip is attached to one end of a stent, is the negative side, the other end of the power of the cathode, the entire chip package to be epoxy resin. Semiconductor chip is composed of two parts, part of the P-type semiconductor, it inside the hole-dominated, the other side is the N-type semiconductor, here is mainly electronic. But linking the two semiconductors, among them the formation of a "PN junction." When the current through the wires role in this chip, will be pushing e-P, P zone in the hole with electronic composite, and then to be issued in the form of photon energy, and this is the principle of LED luminescence. The wavelength of light that is the color of light, is formed by the PN junction of the decisions of the material.Second LED history and development50 years ago, people have to understand semiconductor materials can produce light of the basic knowledge, the first commercial diodes in 1960. English is the LED light emitting diode (LED) acronym, and its basic structure is an electroluminescent semiconductor materials, placed in a wire rack, then sealed with epoxy resin around, that is, solid package, Therefore, the protection of the internal batteries can play the role of line, so the seismic performance LED good.LED is the core of the P-type semiconductor and components of the N-type semiconductor chips, the P-type semiconductor and N-type semiconductor between a transition layer, called the PN junction. In some semiconductor materials in the PN junction, the injection of a small number of carrier-carrier and the majority of the extra time will be in the form of light energy to release, thus the power to direct conversion of solar energy. PN junction on reverse voltage, a few hard-carrier injection, it is not luminous. This use of injection electroluminescent diodes is produced by the principle of light-emitting diodes, commonly known as LED. When it in a positive state of the work (that is, at both ends with forward voltage), the current flows from the LED anode, cathode, semiconductor crystals on the issue from the ultraviolet to infrared light of different colors, light and the strength of the currents.Instruments used for the first LED light source instructions, but all kinds of light colored LED lights in traffic and large screen has been widely applied, have a very good economic and social benefits. The 12-inch red traffic lights as an example, is used in the United States have long life, low-efficiency 140 watt incandescent lamp as a light source, it produced 2,000 lumens of white light. The red filter, the loss-90 percent, only 200 lumens of red light. In the light of the new design, Lumileds companies have 18 red LED light source, including the loss of circuit, atotal power consumption of 14 watts to generate the same optical effect. Automotive LED lights is also the source of important areas.For general lighting, people need more white light sources. The 1998 white LED successful development. This is the GaN LED chip and Yttrium Aluminum Garnet (YAG) package together cause. GaN chip of the Blu-ray (λ p = 465nm, Wd = 30nm), made of high-temperature sintering of the Ce3 + YAG phosphors excited by this Blu-ray after irradiating a yellow, the peak 550 nm. Blue-chip installed in the LED-based Wanxing reflection in the cavity, covered with a resin mixed with YAG thin layer, about 200-500 nm. LED-based tablets issued by the Blu-ray absorption part of the phosphor, the phosphor another part of the Blu-ray and a yellow light mixed, can be a white. Now, the InGaN / YAG white LED, YAG phosphor by changing the chemical composition of the phosphor layer and adjust the thickness of the3500-10000 K color temperature can be colored white. This blue LED through the method by white, constructed simple, low-cost, high technology is mature, so use the most.The development of LED display can be divided into the following phases: first phase 1990 to 1995, mainly monochrome and 16 color graphics screen. Used to display text and simple images, mainly used in railway stations, financial securities, banks, post offices and other public places, as public information display tools. The second stage is from 1995 to 1999, there have been 64, 256 level gray-scale two-color video screen. Video control technology, image processing, optical fiber communication technology applications will enhance the LED display to a new level. LED display control LSI chips special at this time developed by domestic companies, and can be applied. The third stage, from 1999, red, pure green, blue LED in bulk into China, while domestic enterprises in-depth research and development work, using red, green, and blue LED production of full-color display has been widely used , poured into sports stadiums, convention centers, squares and other public places, which will bring the domestic large-screen full-color era. With the rapid development of LED materials market, surface mount device is available from 2001, mainly used in indoor full color, and its high brightness, colorful, low temperature characteristics, the point spacing can be adjusted by different price Requirements were accepted, in just two years time, product sales have more than 300 million yuan, surface mount full-color LED display application market entered the new century. To meet the 2008 Olympic Games, "downsizing" plan, Liard developed a surface mount dual color displays, a lot of time for the training center and game scoring. Full color in Olympic venues, in order to tighten investment, full color way is mostly detachable, live during the Olympic Games as a tool can be used for rental after the event, as the performance of national policies such as public places, tools released by In this way cost recovery as soon as possible. On the market, China's accession to WTO, Beijing's successful Olympic bid and so on, into the development of LED display industry, a new opportunity. Domestic LED display market continues to grow, currently in the domestic market, domestic LED display market share of nearly 95%. LED display theinternational market capacity is expected to 30% a year growth rate. Currently, LED display manufacturers concentrated primarily in Japan, North America, China LED manufacturers in which the insignificant share of exports. According to incomplete statistics, the world, there are at least 150 manufacturers full color, in which products are complete, the larger company has some 30 or so.Third LED advantagesConductor light-emitting diode (LED) as a third-generation semiconductor lighting source. This fantastic product has a lot of advantages: (1) efficient light: spectra of almost all concentrated in the visible light frequency, the efficiency can reach 80% -90%. The luminous efficiency of incandescent visible light efficiency of almost 10% -20% only. (2) high quality of light: not as a result of spectrum UV and infrared, there is no heat, no radiation, is typically a green light illumination. (3) energy consumption of the small: single power generally 0.05-1w, through the cluster can be tailored to meet different needs, and waste very little. As a light source, under the brightness in the same power consumption of only ordinary incandescent 1/8-10.(4) long life: flux attenuation to 70% of the standard life expectancy is 100,000 hours.A semiconductor light can be used under normal circumstances 50 years, even if the long life of the people, life will be used up to two lights. (5) durable and reliable: No tungsten wire, glass and other easily damaged components, non-normal retirement rate is very small, very low maintenance costs. (6) the application of flexibility: small size, can flat pack, easy to develop into a short thin products, make point, line, face various forms of specific applications. (7) Security: working voltage 1.5-5v or less in between the current 20-70mA in between. (8) green: recyclable waste, no pollution, unlike fluorescent lamps containing mercury as ingredients. (9) response time is short: to adapt to frequent and high-frequency switching operation of occasions.Fourth Classification of LED display1, color by color can be divided intoSingle-color display: Single color (red or green).Two-color display: red and green dual-color, 256 gray scale levels, can display 65,536 colors.Full-color screen: red, green, blue color, 256 grayscale full color display can display more than 16 million kinds of colors.2, according to display device classificationLED Digital Display: 7 segment display devices for the digital control code, suitable for production of the clock screen, the interest rate screens, showing the number of electronic display.LED dot-matrix graphic display: display device is arranged by a number of uniform composition of the dot-matrix LED display modules, suitable for broadcast text, image information.LED video display: display devices are formed by a number of light-emitting diodes that can display video, animation and other video files.3, by using the occasion categoriesIndoor Display: LED spots smaller, general Φ3mm - Φ8mm, shows the general area of a few to more than ten square meters.Outdoor Display: dozens of square meters in size to several hundred square meters, high brightness, can work in the sun, with wind, rain, water resistant.4, classified according to light spot diameterIndoor screen: Φ3mm, Φ3.75mm, Φ5mm,Room external screen: Φ10mm, Φ12mm, Φ16mm, Φ19mm, Φ20mm, Φ21mm, Φ22mm, Φ26mmRoom external screen as the basic unit of light emitting tube, LED tube principle is a set of red, green, and blue light-emitting diode sealed in a plastic barrel and jointly develop5, Display a static, horizontal scroll, vertical scroll and flip display. One block module control drive 12 (up to control 24) 8X8 Dot Matrix, a total of 16X48 dot matrix (or 32X48 dot matrix), is a single block of MAX7219 (or PS7219, HD7279, ZLG7289 and 8279, and the like LED display driver module) 12 times (or 24 times)! Can use "cascade" approach the composition of any large dot matrix display. Effects, good power consumption, and the MAX7219 circuit than the use of lower cost.Fifth LED applicationsIt is a semiconductor light-emitting diode by controlling the display, which probably look like that from lots of small red lights are usually formed by the bright lights off to show character. Used to display text, graphics, images, animations, quotes, video, video signals and other information on the display screen.Graphic display and LED display into the video display by the LED matrix blocks. Graphic displays can be synchronized with the computer display Chinese characters, English text and graphics; video display using micro-computer control, graphics, images, and Mao, real-time, synchronization, clear message to the broadcast of a variety of information dissemination, but also shows two dimensional, three-dimensional animation, video, TV, VCD programs and live on. LED display shows the screen brightly colored, three-dimensional sense of strong, static, such as painting, moving as the film is widely used in finance, tax, business, telecommunications, sports, advertising, industrial enterprises, transport, education systems, stations, docks, airports, shopping malls, hospitals, hotels, banks, securities markets, construction market, auction houses, industrial enterprises in management and other public places.LED display can show changes in the numbers, text, graphics and video; not only can be used in the indoor environment can also be used for outdoor environment, with a projector, TV wall, LCD screen can not match advantage.Sixth LED screen test methodA look at Screen size, appearance, smoothness, with the screen connection and so onSecond look after the dead pixel screen light up, not in not within the scope of (in general the screen is basically gone now)Color consistency, display text is normal, display pictures, play full screen full color to white, red, green, and blue.一 LED概述LED（Light Emitting Diode），发光二极管，是一种固态的半导体器件，它可以直接把电转化为光。

毕业设计论文外文文献翻译光信息科学与技术光电目标位置和速度测量系统中英文对照

Electro-optical target system for position and speed measurementAbstractThis paper introduces an electro-optical target system(EOTS) covering the speed range from subsonic to supersonic. This microcomputer-based system has a novel structure and shows the capability of precisely detecting the position as well as the velocity of small caliber projectiles in real time. A prototype EOTS whose target area is 1m2 has been constructed and tested. A speed accuracy of better than 0.3% was achieved. A position accuracy, mainly dependent on the spacing between photodiodes in EOTS, of better than 1mm on a target area of 1m2was also accomplished.Keywords: External ballistics, No contact measurement, Electro-optical techniques, Position measurement, Speed measurement1 IntroductionThe speed and position measurements of projectiles are two important items in ballistic research. To determine these parameters precisely one needs an accurate measuring system. A conventional method, namely the hanging up(and taking down) of target discs[l], though accurate in position measuring, is time consuming. A shot-position indicator(SPI), described in Reference 2, can measure the position of a high speed projectile by acoustic measurement. However, the SPI does not provide the speed information; neither does the conventional method. Besides, the SPI is used within the limits of supersonic projectiles.To measure the speed and position of projectiles rapidly and simultaneously, different electro-optical based systems have been proposed 3-5]. These systems have the ability to cover the speed range from subsonic to supersonic. One system, called the target measurement system(TMS)[3], uses vertical and horizontal banks of light sources to form two perpendicular light grids that construct the target area. Another system, called the electro-optical projectile analyzer[4], uses the same principle as TMS, but simplifies light sources with fiber optics bundles and a single light source in each light grid. The other system, called the electronic yaw screen(EYS)[5], uses a solid state laser that is collimated and directed to a one-dimensional beam expander system to form a fan-shaped light screen. This light screen then is reflected by a mirror to construct a portion of the target area. The light screen is more precise than the light grid because there is no dead zone in the target area as with the light grid system.From the aspect of speed and position measurement, we take advantage of the above systems and propose a novel system; the electro-optical target system(EOTS)[6]. We use a cylindrical mirror that reflects the incident laser beam into a 90º fan-shaped light screen. Two such light screens construct a two-dimensional positioning system. We even propose a bent cylindrical mirror to generate a 90º light screen with a few degrees extended in a direction normal to the light screen to reduce the sensitivity to vibrations.A prototype EOTS, whose target area is 1m2 and measured speed range is from 50m/s to 1200m/s, has been constructed and tested. A speed range of up to 5000m/s can also be expected according to the simulation results from the electronic circuit using PSpice[7]. Finally, a nine-point testing result from a 0.38in. pistol is shown in this paper. The result shows that the standard deviation of position accuracy is less than 1mm.2 Basic principle of EOTSFig. 1 shows the optical configuration of EOTS. A laser beam from a He-Ne laser is directed onto a cylindrical mirror. The reflected laser beams create a fan-shaped light screen and are directed onto photodiodes that are neatly arranged into an L-shaped photodiode array. EOTS uses two laser sources, two cylindrical mirrors and two photodiode arrays, which are arranged on the opposite sides of the EOTS body to form two fan-shaped light screens. Each light screen is combined with its own signal processing circuit to construct an optical gate. Although there is a distance between the two parallel light screens, viewed from a distance point, these fan beams intersect in a region of space called the target area (Fig. 2). A projectile can be measured only if it travels through this target area.Fig. 1 Optical configuration of EOTSFig. 3 shows the shot position of the projectile is calculated. The target area, for the convenience of illustration, is a square of dimension D on each side. The number of photodiodes on the L-shaped photodiode array is 2N . Each photodiode is numbered in order, as shown in the figure. For illustration clarity, only the photodiode array and the cylindrical mirror of the first optical gate are shown. The projectile is considered to be incident normally to the first and to the second optical gate in sequence. When the projectile blocks the light screens, the respective photodiodes will be activated by the disturbance. In the first optical gate, the laser beam from the cylindrical mirror to each photodiode makes a unique angle with the y-axis. This angle is measured counter-clockwise from the axis. The angle with respect to a photodiode, numbered n, can be calculated as 12()()arctan ,1n n n N Nδ1-=≤≤ (1) and12()arctan ,12(2)N n N n N N n δ1=+≤≤-+ (2) If certain photodiodes, numbered from j to k , are activated by projectiles, then the shot-position angle δ1, is given by()()2j k δδδ111+= (3)Fig. 2 Intersections of the two light screens in the target area Similarly, the shot-position angle of the second optical gate δ2, measured clockwise from the minus y-axis, is decided. After the two angles have been measured, theFig. 3 Illustration of shot-position calculation shot position of the projectile is deduced in Cartesian coordinates as212tan tan tan D y δδδ=+ (4) and1tan z y δ= (5)If S is the distance between the two light screens, then the average speed v for the projectile passing through the distance S is given byS v T= (6) where T is the time interval for the projectile to pass through distance S .3 Configuration of EOTS3.1 Optical system of EOTSWe use a He-Ne laser directed onto a cylindrical mirror to create a light screen. The relation among the laser beam diameter d, the cylindrical mirror diameter w and the beam expanding angle φ is shown in Fig. 4. This relation can be calculated as2arcsind w φ=2 (7) To create a light screen of which φ equals 90º, the ratio of w to d is 2.8. Because the He-Ne laser beam has Gaussian distribution and each photodiode on the photodiode array has a different distance to the cylindrical mirror, the received laser power at each photodiode is not constant. This will influence the speed accuracy of EOTS (see Fig. 6 and Section 4.1).3.2 Analogue circuitryEOTS has 2N analogue channels in each of its two optical gates. Every analogue channel has the same structure. Each analogue channel contains a photodiode, a linear amplifier, a band-pass filter and a comparator. The linear amplifier amplifies the signal coming from the photodiode. The band-pass filter filters noises such asFig.4 Laser beam directs on a cylindrical mirrorbugs flying through the light screen and flicker of other light sources nearby. The comparator compares the output V0 , coming from the filter with a threshold voltage V TH. If V0is higher than V TH, then the comparator will activate a flip-flop (FF) to change the state.3.3 Digital circuitryFig.5 is the block diagram of the digital signal processing circuit. Input coming from the analogue channel is fed to a relative FF. When the projectile blocks the light screen of the first optical gate, the state-changed FF s will make the output of the NAND gate U1 change state. The U1 locks all FF s of the first optical gate to protect genuine projectile data from the influence of shock waves behind the projectile, and starts the counter U5 that operates at a clock frequency of 10MHz. As the projectile blocks the light screen of the second optical gate, the circuit of the second optical gate functions as the circuit of the first optical gate did, but stops the counter. Moreover, the NAND gate U2 passes an interrupt signal (INT) to the central processing unit (CPU) while U5 is being stopped. The CPU then recognizes the interrupt request, picks the projectile data up, and resets U5 and all FF s for the next shot, in sequence. In Fig. 5, the counter relates the time interval T in eqn. 6. Besides, every photodiode is assigned a specific FF and every FF is given a relative address. Therefore, the CPU will be able to identify which photodiode generates the signal, to decide the impact position of eqns. 1-5, and to calculate the speed of the projectile.Fig. 5 Block diagram of digital signal processing circuit 4 Accuracy of EOTS4.1 Accuracy of speed measurementThe accuracy of projectile velocity measurement with sky-screens has been deduced by Hartwig [8] asS v T v v S∆+∆∆≤ (8) where parameters were the same as eqn. 6 used. Δv , ΔS and ΔT are values of maximum error in v , S and T , respectively. In EOTS, photodiodes are directed by nonuniform optical power, as described in Section 3.1, which implies that different analogue channels will have different response times, as though they are activated in the same way. Fig. 6 describes the typical input and output waveforms of an analogue channel when a projectile passes through the light screen. The dotted line is theFig. 6 Typical input and output waveform of analogue channelresponse of the weaker optical input with respect to the solid line. In this Figure, the optical power density directed onto the photodiode is considered to be constant along the x-axis. Referring to the solid line, the projectile touches the light screen at T1and entirely blocks laser beams at T2; the activated photodiode current I D drops from I DH to I DL.The output voltage V0of the analogue channel then rises to a saturation voltage V sat. The counter is not triggered until V0is larger than V TH. The interval from T1 to the time that V0equals V TH is called the response time t r From Fig. 6, we can realise that a different input power variation with time will produce a different output response time t r. Therefore, the ΔT of eqn. 8 should include Δt r, for EOTS, where Δt r, is the worst-case difference, i.e., the largest t r of the first optical gate minus the smallest t r of the second optical gate. Table 1 lists the simulation results of Δt r of the analogue circuit with respect to different projectile velocities using PSpice.Table 1 Simulation results of Δt, respect to projectile speed4.2 Accuracy of position measurementConsidering an EOTS structure in Fig. 3, if a photodiode, numbered n, is activated by a projectile, the exact shot-position angle δe , will be within the range1arctan()arctan(),1e n n n N N Nδ-≤≤≤≤ (9) orarctan()arctan(),12212e N N N n N N n N nδ≤≤+≤≤-+- (10) Referring to eqns. 1 and 2, eqns. 9 and 10 express that the worst-case deviation of δe , Δδ is caused by half-photodiode-spacing shift of measuring ambiguity. Thus, the deviations of the y-axis and z-axis can be deduced as1212y y y δδδδ∂∂∆=∆+∆∂∂ (11) and1212z z z δδδδ∂∂∆=∆+∆∂∂ (12) Where Δδ1 and Δδ2 are Δδ of the first and the second optical gate, respectively.2122112sec tan (tan tan )D y δδδδδ∂=-∂+ (13) 2122212tan sec (tan tan )D y δδδδδ∂=∂+ (14) 22122112sec tan (tan tan )D z δδδδδ∂=∂+ (15) and22122212tan sec (tan tan )D z δδδδδ∂=∂+ (16) It is obvious from eqns 9-16 that N has to be increased as the position accuracy needs to be better for a same size of D.Fig. 2 shows the intersection of the two light screens in the target area where intervals between photodiodes are considered to be constant. As indicated in this Figure, different detector positions will produce different resolutions. Fig. 7 shows simulation results of the worst-case deviations on the y-axis (or z-axis). The shot-position angle δ1, is fixed at 45º and the activated photodiode of the second optical gate varies from number 40 to 360 on an EOTSwith D = 1000mm and 2N = 400. Fig. 7 shows deviations on the y-axis (or z-axis) of less than 1mm corresponding to certain photodiodes that are numbered approximately from 120 to 280.A pentagon-shaped region, which is shown in Fig. 2 and has an accuracy better than 1mm, also corresponds to those photodiodes.Fig. 7 The worst-case deviation on y-axis and z-axis as δ1 is fixed at 45º5 Experimental resultsA prototype EOTS was used in the experiments. The main specifications of the system are listed as follows: d = 0.81mm, w = 2.5mm, S = 635mm, D = 1000mm, 2N = 384 and laser output optical power P = 7.5mW. We hung up a paper target behind EOTS for comparison. Fig. 8 shows the y and z coordinates of nine impact points from a 0.38in. pistol. The impact positions and the velocities were measured by EOTS. In Fig. 8, the two crosses at the bottom indicate the positions of cylindrical mirrors. Table 2 compares the results generated by EOTS with the measurement results from the paper target. The standard deviation is less than 1mm.6 Discussion and conclusionsThis paper presents a novel electro-optical target system for small calibre projectiles. Position and speed data can be generated instantaneously by the microcomputer-based control unit with the addition of appropriate software. The most accurate region of positioning, which is a pentagon-shaped area, distributes over the centre of the target area. The accuracy of position and speed measurement has been analyzed in this paper. To improve the speed accuracy, we should reduce the influence of the response time difference. To increase the distance between the two light screens, of course, is another method to improve the speed accuracy, but the position accuracy will become worse. To improve position accuracy, the photodiode array which has less space between two adjacent photodiodes is suggested.Fig. 8 The computer printout of EOTS, origin is shifted to centre of the target area The measured speed range of EOTS is from subsonic to supersonic. A speed accuracy of better than 0.3% is accomplished. With a different design concept, EOTS need not synchronized with the firing signal as EYS. It is always ready for any advancing projectile as the power of EOTS has been turned on.Fig. 9 Laser beam directs on a bent cylindrical mirrorIf a slightly bent cylindrical mirror were used (Fig. 9), the light screen could extend a few degrees in the x-direction. This makes optics alignment easier and insensitive to vibrations. However, the surface quality of the cylindrical mirror is critical to the uniformity of the fan-shaped beam in the x-direction. The nonuniformity of the fan beam in the x-direction will enhance the sensitivity to vibrations.Table 2 List of results measured by EOTS and by artificialComparing EOTS with EYS and other conventional methods, EOTS has the following advantages:(a) It can measure position and speed precisely and simultaneously.(b) Its optical system is simple and easy to set up.(c) It is insensitive to vibrations if a bent cylindrical mirror is used.(d) Its speed range covers subsonic to supersonic.References[1] BETTERMANN, P, and MAYER, F. Handbook on weaponry. Rheinmetall GmbH, Dusseldorf, 1982.[2] FARRAR, C.L., and LEEMING, D.W. Military ballistics. Brassey’s Publishers Limited, 1983.[3] CRITTENDEN, E.C., KING, R.A., and ANDREWS, T.C. Target measurement system for precise projectile location. US Paten No.3727069, 1973.[4] BAILEY, T.B., and BATES, J. Electro-optical projectile analyzer. US PatentNo.4272189, 1981.[5] DECK, L.L. An optical device for rapid measurement of the speed, dispersion, attack angle and shock wave of high velocity small caliber projectiles. Proceeding of 10th International Symposium on Ballistics, 1987, 1,pp. 1-9.[6] LU, S.T., YU, A.T, and CHOU, C. Electro-optics target for position and speed measurement, Proc. SPIE, 1988, 981, pp.250-254[7] TUINENGA, P.W. SPICE a guide to circuit simulation and analysis using PSpice. Prentice-Hall, 1988.[8] HARTWIG, R. Accuracy of velocity measurement of projectiles with fins and tracers by means of sky-screens. J. Ballistics, 1986, 9, (3), pp.2299-2310.光电目标位置和速度测量系统摘要本文介绍了一种光电目标系统(EOTS)，其速度测量范围从亚音速到超音速。

毕业设计英文翻译1

Introduction to Optical Fiber Communication One of the most important technological developments during the 1980s has been the emergence of optical fiber communication as a major international industry. One indication of the extent of this development is the total length of installed fiber, which was estimated to be 3.2 million kilometers in the U.S. alone by the end of 1987.Over 90% of this fiber was placed in service during the time period of 1982-1987.Long-haul trunk installations have been dominated, accounting for about 95% of the fiber in the U.S.Although telecommunication is the rational for most of the current interest in fiber optics, this was not the case during the early days of the technology. The researchers who produced the first clad glass optical fibers in the early 1950s were not thinking of using them for communications; they wanted to make imaging bundles for endoscopy. Fiber optics was already a well-established commercial technology when the famous paper by Kao and Hockham, suggesting the use of low-loss optical fibers for communication, appeared in 1966.The first low-loss (20 dB/km) silica fiber was described in a publication which appeared in October of 1970.The date of this publication is sometimes cited as the beginning of the era of fiber communication. Although this development did receive considerableattention in the research community at the time, it was far from inevitable that a major industry would evolve. The 20 dB/km loss figure was still too high for long-haul telecommunication systems. The fibers were fragile, and a way to protect them would have to be found. There were no suitable light sources. Researchers did not know whether field termination and splicing of optical cables would ever be produced economically enough for the technology to play a ,major role in the marketplace.Although the technological barriers appeared formidable, the economic potential was very significant. As a consequence, research and development activity expanded rapidly, and a number of important issues were resolve during the early 1970s.During the middle and late 1970s, the rate of progress toward marketable products accelerated as the emphasis shifted from research to engineering. Fibers with losses approaching the Rayleigh limit of 2 dB/km at a wavelength of 0.8 um, 0.3dB/km at 1.3 um, and 0.15dB/km at 1.55 um, were produced in the laboratory. Microbend loss problems were overcome through the use of improved fiber coatings and cabling techniques. Rugged cables and multifiber connectors were produced for field installation. Room temperature threshold currents for commercial gallium aluminum arsenide lasers operating in the 0.8 to 0.85 un spectral region were reduced to the 20 to 30 mA range, and projected lifetimes inthe 100 000 to 1000 000 hour range were claimed for both lasers and LEDs. Light sources and improved photodetectors which operated near 1.3 um were developed to take advantage of the low fiber loss and dispersion in this “ longer wavelength region ”. Several major field trials were undertaken during this period, including AT&T’s Atlanta experiment and Chicago installation, and Japan’s subscriber access project.Improvements in component performance, cost, and rellability by 1980 led to major commitments on the part of telephone companies. Fiber soon become the preferred transmission medium for long-haul trunks. Some early installations used 0.8 um light sources and graded-index multimode fiber, but by 1983, designers of intercity links were thinking in terms of 1.3 um, single-mode systems. The single-mode fiber, used in conjunction with a 1.3 um laser, provides a bandwidth advantage which translates into increased repeater spacings for high date rate systems.Date rates for installed fiber optic systems have recently moved into gigabit per second range. Such systems use the spectrally pure distributed-feedback lasers to minimize fiber dispersion effects. Fibers designed for low dispersion at 1.55 um wavelength, which corresponds to minimum fiber loss, are now commonly used in long distance transmission. The use of wavelength multiplexing to further increase the fiber information capacity is becoming more widespread.The potential of fiber optics in other areas is only beginning to berealized. Fiber optic networks for computer systems and offices are becoming more prominent. In the telephone system, the use of fiber optics for interconnecting central offices within a metropolitan area and for lower levels in the switching hierarchy is still increasing rapidly. Fiber links to the home have been used in demonstration projects. Many observers believe that national telephone systems will eventually be upgraded to handle video bandwidths by using fiber optics. These wideband subscriber loop systems would provide access to services such as picturephone, video entertainment. Widespread installation of these broadband services will become economically feasible.光纤通信介绍20世纪80年代一项最重要的技术发展是光纤通信成为一个主要的国际性产业。

关于led的毕业设计英文翻译

Very Low-Cost Sensing and CommunicationUsing Bidirectional LEDsPaul Dietz, William Yerazunis, Darren Leigh TR2003-35 July 2003Abstract. A novel microprocessor interface circuit is described whichcan alternately emit and detect light using only an LED, two digitalI/O pins and a single current limiting resistor. Thistechnique is firstapplied to create a smart illumination system that uses a single LED asboth light source and sensor. We then present several devices that usean LED as a generic wireless serial data port. An important implicationof this work is that every LED connected to a microprocessor can bethought of as a wireless two-way communication port. We present thistechnology as a solution to the “last centimeter problem”, because itpermits disparate devices to communicate with each other simply andcheaply with minimal design modification.1 IntroductionLight Emitting Diodes, or LEDs, are one of the most common types of inter-face components. Their diverse applications include numeric displays, flashlights,liquid crystal back lights, vehicle brake lights, traffic signals and the ubiquitous power-on indicator light. Because LEDs are so commonly used as light emitters it is easy to forget that they are fundamentally photodiodes, and as such, are light detectors as well. Although LEDs are not optimized for light detection, they are very effective at it. This inter change ability between solid-state light emission and detection was widely publicized in the 1970’s by Forrest W. Mims [1][2], but has been largely forgotten by LED users.1.1 Ambient Illumination Sensing with LEDRecently, we have been investigating improvements for infrared remote controls of the type commonly used with consumer audio/video equipment. An area of immediate interest was the pushbutton illumination used on many remote controls. To activate the backlight, you must press a button that is nearly impossible to locate in the dark! We resolved to rectify this situation.Our first solution was to use a capacitive proximity sensor (similar to the one described in [4]) to activate the remote control backlight during active handling. Unfortunately, turning on the backlight every time the remote is handled substantially decreases battery life, not only because the user often holds onto the remote continuously but also because the remote is sometimes used under good lighting conditions when the backlight is not needed. While a mode switch could be added, this would be little better than the original situation. The obvious step was to add a light sensor to turn on the backlight only when needed. CdS photocells are inexpensive, but providing an optical path to the cell would add significant cost and complexity to the mechanical design. Recalling the photosensitive nature of LEDs, we decided to investigate using the backlight LED itself as the light detector. We developed a simple circuit for this purpose that requires one additional microcontroller I/O pin, but no other additional components compared to a traditional LED driver. The success of the simple LED emitter/receivercircuit inspired us to consider other applications. For example, by quickly switching between the forward-biased (light-emitting) and back-biased (light-sensing) modes, it is possible to build an LED-based light source that appears to be constantly on, but is in fact periodically measuring the ambient lighting level and using this information to automatically adjust the brightness level of the LED. Our demonstration device, shown in Figure 6, has a capacitance sensor to determine that the device is being manipulated and an LED sensor/emitter to provide the backlight function.1.2 LEDComm: Bidirectional LED CommunicationWhile the measurement of ambient light levels has many applications, a more intriguing use of this technology is to transmit data back and forth between LEDs pointed at each other. We call this “LEDComm”. We have developed simple prototypes that allow two-way serial data communication between LEDs over a distance of several centimeters.One possible application of LEDComm is to replace Radio Frequency Identification (RFID) systems (e.g. [5]) for payment authorization and access control.To test this concept, we have created an inexpensive keychain-size device called an iDropper that can receive, store, and transmit data. Unlike RFID systems,iDroppers support true peer-to-peer communication, allowing new functionality such as directly transferring authority between devices without need of a special reader device. The implications of LED-based data communication are significant. Every LED connected to a microprocessor can be thought of as a wireless communication port. Compared with other short-range wireless technologies such as IrDA [7] and Bluetooth [8], LEDComm has a far more limited range, and a much slower data rate. But LEDComm can be implemented at a fraction of the cost, and in many cases, may even be free. This is because LEDComm is essentially a software interface technique using existing hardware with minimal modification. LEDComm allows us to implement communication functions in places where traditional techniques are too expensive. The power light on many consumer appliances can now become a maintenance port for reading service information or uploading new firmware. Cell phones can transfer contact information to other phones by holding their displays next to each other. For automobiles, the standard expensive service connector can be bypassed, and all data transferred through the “Check Engine”light. (An automobile owner could even use an iDropper to capture the car’s fault log and transmit it to the service center before a service appointment, insuring that the proper tools and spare parts will be immediately available when the vehicle is brought in.) There are many possible applications.In the following sections, we describe the basic bidirectional LED microprocessor interface circuit and its use in the smart backlight. We then give a full description of LEDComm, iDroppers and various applications.2 The Bidirectional LED InterfaceLight emitting diodes emit light in a fairly narrow frequency band when a smallcurrent isapplied in the correct direction. Because the current-voltage characteristic is exponential,it is difficult to control a voltage applied directly acrossan LED accurately enough to attaina desired current; some means must beused to limit the current. Indiscrete systems, this is typically done by placing aresistor in series as shown in Figure 1.Since most microprocessor I/O pins cansink more current than they can source, the configuration shown in the figure isthe most common way of driving an LED from a microprocessor.The LED is a photodiode that is sensitive to light at and above the wavelength at which itemits (barring any filtering effects of a colored plastic package).Under reverse biasconditions, a simple model for the LED is a capacitor in parallel with a current source which models the optically induced photocurrent.. It is this photocurrent that we would like to measure.An inexpensive way to make a photodetector out of an LED is to tie theanode to ground and connect the cathode to a CMOS I/O pin driven high.This reverse biases the diode, and charges the capacitance.Next switch the I/Opin to input mode, which allows the photocurrent to discharge the capacitancedown to the digital input threshold. By timing how long this takes, we get ameasurement of the photocurrent and thus the amount of incident light. The circuits ofFigures 1 and 2 can be combined to create a general bidirectional microprocessorinterface to an LED as shown in Figure 4. This is identicalto the circuit of Figure 1, exceptthat now the resistor/LED combination isplaced between two I/O pins. Figure 5 shows how the pins are driven for the two modes. Figure 5a showsthe “Emitting”mode where current is driven in the forward direction, lightingthe LED. Figure 5b shows “Reverse Bias”mode, which charges the capacitanceand prepares the system for measurement. The actual measurement is made in“Discharge”mode shown in Figure 5c. Since the current flowing into a CMOSinput is extremely small, the low value current limiting resistor has little impacton the voltage seen at the input pin. Asbefore, we simply time how long ittakes for the photocurrent to discharge the capacitance to the pin’s digital inputthreshold.The result is a simple circuit that can switch betweenemitting andreceiving light.Because the circuit changes required to provide this bidirectional communication feature consist of only one additional I/O pin and printed circuit boardtrace (which can be provided at design time for zero additional hardware cost) .we claim that adding this hardware feature to a device is essentially free. Ofcourse,software and CPU runtime are also necessary to make this work.Compare this to the costof adding IrDA or Bluetoothto a product. Using even asimple mechanical connector can costseveral dollars because of the requiredlevel-shifting and electrostatic discharge protection circuitry. Using an existing LED for communication can alsosave manufacturing costs because expensive plastic molds for the housing neednot be altered to accommodate a dedicated infrared transceiver, antenna orphysical connector.3 The Smart BacklighThe Smart Backlight is one application of the bidirectional LED circuit. As noted previously, the idea of the smart remote control backlight is to turn on the backlighting before the user has to press a button. Also, to conserve power, we wish to turn on this backlight only when it is actually dark enough to need It.To demonstrate this function we created the prototype shown in Figure 6,with the complete schematic shown in Figure 7. This circuit uses a capacitive proximity detector to determine handling state. Although thebasic capacitance measurement circuit is identical to that used in the buffer phone [4], we process the data to look for active handling (changes in capacitance) rather than simple presence (increased capacitance). Many users will continue to hold a remote even when they are not actively using it, so the detection of active handling is critical for extending battery life. Of course, as soon as the user wishes to actively use the remote again, any significant motion turns the light back on.The smart backlight functions as follows: periodically, the microprocessor wakes from sleep, and measures the capacitance. If no active handling is detected, the processor goes back to sleep. Otherwise, a light measurement is made with the LED. If the room is dark, it turns on the backlight for at least two seconds. While the backlight is on, it continues to check for active handling. Each time handling is detected, the backlight timer is reset to stay on for another two seconds.Since remote controls already contain low-end microprocessors, adding this functionality costs very little. The proximity electrodes can be part of the printed circuit board, eliminating the need for special tooling. If there are spare I/O pins available, the only additional component is a single, inexpensive capacitor for the capacitance sensor.One might wonder if the constantly running proximity detector adversely impacts battery life. In fact, the circuit draws microwatts of power; the prototype ran continuously for 6 months on a single type CR2032 coin-cell “watch”battery. Remote controls typically use AAA or AA batteries with a storage capacity an order of magnitude higher than the coin-cell, so the power draw would be insignificant compared to the batteries’self-discharge characteristics.4 Bidirectional Communication ProtocolsIn our initial experimentation with the smart backlight, we often used LED-based flashlights to test the light detecting circuit. This suggested to us that LED-to-LED communication was feasible. We constructed a simple test setup using two identical, generic PIC microcontroller boards with RS-232 interfaces as shown in Figure 8.These test boards use a simple protocol for data transfer which allows two unsynchronized devices to phase-lock to each other and exchange pulse-width- modulated data bidirectionally. A basic explanation of the protocol is that the two devices take turns flashing their LEDs at each other. A short flash indicates a 0 or SPACE state, and a long flash indicates a 1 or MARK state.The protocol starts out on powerup with the device performing an idling cycle, transmitting a 1 millisecond light pulse followed by a 4 millisecond receive period. During the receive period, the device executes 40 light measurements, each one taking 100 microseconds. These light measurements provide only one bit of resolution, i.e. whether the incoming light flux is above or below the digital I/O pin’s threshold (nominally about 1.5 volts). With only normal room light incident upon the LED there is insufficient photocurrent to discharge the capacitance below the threshold during the 100 microsecond receive period.The oscilloscope trace in Figure 9 shows the voltage at the LED cathode during several light measurements with normal illumination. The vertical scale is 1 volt/divisionand the horizontal is 100 microseconds/division. The capacitance is initially charged to about 5 volts and then allowed to discharge. Notice that the voltage never drops below the threshold and so the microcontroller will always read the pin as a 1.Figure 10 is an oscilloscope trace of the same setup, but with the LED being illuminated by another LED. The capacitance discharges completely during the measurement period, bringing the I/O pin voltage well below threshold and causing the pin to read as a 0. The idling cycle continues until at least two measurement times in succession indicate “light seen”. At this point, the device assumes an incoming pulse of light from a similar device has been detected, and shifts from the idling loop of 1 millisecond ON then 4 milliseconds OFF to a slightly faster synchronizing loop,。

led照明毕业论文中英文资料外文翻译文献

led照明毕业论文中英文资料外文翻译文献Renewable and Sustainable Energy ReviewsHigh-brightness LEDs—Energy efficient lighting sources and their potential in indoor plant cultivation ABSTRACTThe rapid development of optoelectronic technology since mid-1980 has significantly enhanced the brightness and efficiency of light-emitting diodes (LEDs). LEDs have long been proposed as a primary light source for space-based plant research chamber or bioregenerative life support systems. The raising cost of energy also makes the use of LEDs in commercial crop culture imminent. With their energy efficiency, LEDs have opened new perspectives for optimizing the energy conversion and the nutrient supply both on and off Earth. The potentials of LED as an effective light source for indoor agriculturalproduction have been explored to a great extent. There are many researches that use LEDs to support plant growth in controlled environments such as plant tissue culture room and growth chamber. This paper provides a brief development history of LEDs and a broad base review on LED applications in indoor plant cultivation since 1990.Contents1. Introduction2. LED development.3. Color ratios and photosynthesis4. LEDs and indoor plant cultivation.4.1. Plant tissue culture and growth4.2. Space agriculture84.3. Algaculture4.4. Plant disease reduction5. Intermittent and photoperiod lighting and energy saving6. Conclusion1. IntroductionWith impacts of climate change, issues such as more frequent and seriousdroughts, floods, and storms as well as pest and diseases are becoming more serious threats to agriculture. These threats along with shortage of food supply make people turn to indoor and urban farming (such as vertical farming) for help. With proper lighting, indoor agriculture eliminates weather-related crop failures due to droughts and floods to provide year-round crop production, which assist in supplying food in cities with surging populations and in areas of severe environmental conditions.The use of light-emitting diodes marks great advancements over existing indoor agricultural lighting. LEDs allow the control of spectral composition and the adjustment of light intensity to simulate the changes of sunlight intensity during the day. They have the ability to produce high light levels with low radiant heat output and maintain useful light output for years. LEDs do not contain electrodes and thus do not burn out like incandescent or fluorescent bulbs that must be periodically replaced. Not to mention that incandescent and fluorescent lamps consume a lot of electrical power while generating heat, which must be dispelled from closed environments such as spaceships and space stations.2. LED developmentLED is a unique type of semiconductor diode. It consists of a chip of semiconductor material doped with impurities to create a p–n junction. Current flows easily from the p-side (anode), to the n-side (cathode), but not in the reverse direction.Electrons and holes flow into the junction from electrodes with different voltages. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon. The color (wavelength) of the light emitted depends on the band gap energy of the materials forming the p–n junction. The materials used for an LED have a direct band gap with energies corresponding to near-infrared, visible or near-ultraviolet light.The key structure of an LED consists of the die (or light-emitting semiconductor material), a lead frame where the die is placed, and the encapsulation which protects the die (Fig. 1).Fig.1LED development began with infrared and red devices made with gallium arsenide. Advances in materials science have made possible the production of devices with ever-shorter wavelengths, producing light in a variety of colors. J.Margolin reported that the first known light-emitting solid state diode was made in 1907 by H. J. Round. No practical use of Round’s diode was made for several decades until the invention of the first practical LED by Nick Holonyak, Jr in 1962. His LEDs became commercially available inlate 1960s. These GaAsP LEDs combine three primary elements: gallium, arsenic and phosphorus to provide a 655nm red light with brightness levels of approximately 1–10 mcd at 20mA. As the luminous intensity was low, these LEDs were only used in a few applications, primarily as indicators. Following GaAsP, GaP (gallium phosphide) red LEDs were developed. These device sex hibit very high quantum efficiencies at low currents. As LED technology progressed through the 1970s, additional colors and wavelengths became available. The most common materials were GaP green and red, GaAsP orange, and high efficiency red and GaAsP yellow. The trend towards more practical applications (such as in calculators, digital watches, and test equipment) also began to develop. As the LED materials technology became more advanced, the light output was increased, and LEDs became bright enough to be used for illumination.In 1980s a new material, GaAlAs (gallium aluminum arsenide) was developed followed by a rapid growth in the use of LEDs. GaAlAs technology provides superiorperformance over previously available LEDs. The voltage requirement is lower, which results in a total power savings. LEDs could be easily pulsed or multiplexed and thus are suitable for variable message and outdoor signs. Along this development period, LEDs were also designed into bar code scanners, fiber optic data transmission systems, and medicalequipment. During this time, the improvements in crystal growth and optics design allow yellow, green and orange LEDs only a minor improvement in brightness and efficiency. The basic structure of the material remained relatively unchanged.As laser diodes with output in the visible spectrum started to commercialize in late 1980s, LED designers used similar techniques to produce high-brightness and high reliability LEDs. This led to the development of InGaAlP (indium gallium aluminum phosphide) visible light LEDs. Via adjusting the energy band gap InGaAlP material can have different color output. Thus, green, yellow, orange and red LEDs could all be produced using the same basic technology. Also, light output degradation of InGaAlP material is significantly improved.Shuji Nakamura at Nichia Chemical Industries of Japan introduced blue LEDs in 1993. Blue LEDs have always been difficult to manufacture because of their high photon energies (>2.5 eV) and relatively low eye sensitivity. Also, the technology to fabricate these LEDs is very different and less advanced than standard LED materials. But blue is one of the primary colors (the other two being red and green). Properly combining the red, green, and blue light is essential to produce white and full-color. This process requires sophisticated software and hardware design to implement. In addition, the brightness level is low and the overall light output of each RGB die being used degrades at a different rate resulting in an eventual color unbalance. The blue LEDs available today consist of GaN (gallium nitride) and SiC (silicon carbide) construction. The blue LED that becomes available in production quantities has result in an entire generation of new applications that include telecommunications products, automotive applications, traffic control devices, and full-color message boards. Even LED TVs can soon become commercially available.Compare to incandescent light’s 1000-h and fluorescent light’s 8000-h life span, LEDs have a very significantly longer life of 100,000 h. In addition to their long life, LEDs have many advantages over conventional light source. These advantages include small size, specific wavelength, low thermal output, adjustable light intensity and quality, as well as high photoelectric conversion efficiency. Such advantages make LEDs perfect for supporting plant growth in controlled environment such as plant tissue culture room and growth chamber. Table 1 is a list of some common types of LEDs as compiled from .The chlorophyll molecules in plants initiate photosynthesis bycapturing light energy and converting it into chemical energy to help transforming water and carbon dioxide into the primary nutrient for living beings. The generalized equation for the photosynthetic process is given as:CO2 + H2O—light—>（CH2O）+ O2where (CH2O) is the chemical energy building block for thesynthesis of plant components.Chlorophyll molecules absorb blue and red wavelengths most efficiently. The green and yellow wavelengths are reflected or transmitted and thus are not as important in the photosyntheticprocess. That means limit the amount of color given to the plants and still have them grow as well as with white light. So, there is no need to devote energy to green light when energy costs are aconcern, which is usually the case in space travel.The LEDs enable researchers to eliminate other wavelengths found within normal white light, thus reducing the amount of energy required to power the plant growth lamps. The plants grow normally and taste the same as those raised in white light.Red and blue light best drive photosynthetic metabolism. These light qualities are particularly efficient in improving the developmental characteristics associated with autotrophic growth habits. Nevertheless, photosynthetically inefficient light qualities also convey important environmental information to a developing plant. For example, far-red light reverses the effect of phytochromes, leading to changes in gene expression, plant architecture, and reproductive responses. In addition, photoperiod (the adjustment of light and dark periods) and light quality (the adjustment of red, blue and far-red light ratio) also have decisive impacts on photomorphogenesis.The superimposed pattern of luminescence spectrum of blue LED (450–470 nm) and that of red LED (650–665 nm) corresponds well to light absorption spectrum of carotenoids and chlorophyll. Various plant cultivation experiments are possible when these twokinds of LED are used with the addition of far-red radiation (730–735 nm) as the light source. Along the line of the LED technology advancement, LEDs become a prominent light source for intensive plant culture systems and photobiological researches. The cultivation experiments which use such light sources are becoming increasingly active. Plant physiology and plant cultivation researches using LEDs started to peak in 1990s and become inevitable in the new millennium. Those researches have confirmed that LEDs are suitable for cultivation of a variety of algae,crop, flower, fruit, and vegetable.Some of the pioneering researches are reviewed in the followings.Bula et al. have shown that growing lettuce with red LEDs in combination with blue tubular fluorescent lamp (TFL) is possible. Hoenecke et al. have verified the necessity of blue photons for lettuce seedlings production by using red LEDs with blue TFL. As the price of both blue and red LEDs have dropped and the brightness increased significantly, the research findings have been able to be applied in commercial production. As reported by Agence France Press, Cosmo Plant Co., in Fukuroi, Japan has developed a red LED-based growth process that uses only 60% of electricity than a fluorescent lighting based one.Tennessen et al. have compared photosynthesis from leaves of kudzu (Pueraria lobata) enclosed in a leaf chamber illuminated by LEDs versus by a xenon arc lamp. The responses of photosynthesis to CO2 are similar under the LED and xenon arc lamps at equal photosynthetic irradiance. There is no statistical significant difference between the white light and red light measurements in high CO2. Some leaves exhibited feedback inhibition of photosynthesis which is equally evident under irradiation of either lamp type. The results suggest that photosynthesis research including electron transport, carbon metabolismand trace gas emission studies should benefit greatly from the increased reliability, repeatability and portability of a photosynthesis lamp based on LEDs.Okamoto et al. have investigated the effects of different ratios of red and blue (red/blue) photosynthetic photon flux density (PPFD) levels on the growth and morphogenesis of lettuce seedlings. They have found that the lettuce stem length decreases significantly with an increase in the blue PPFD. The research has also identified the respective PPFD ratio that (1) accelerates lettuce seedlings’stem elongation, (2) maximizes the whole plant dry weight, (3) accelerates the growth of whole plants, and (4) maximizes the dry weights of roots and stems. Photosynthesis does not need to take place in continuous light. The solid state nature allows LEDs to produce sufficient photon fluxes and can be turned fully on and off rapidly (200 ns), which is not easily achievable with other light sources. This rapid on–off feature has made LEDs an excellent light source for photosynthesis research such as pulsed lighting for the study of photosynthetic electron transport details. The off/dark period means additional energy saving on top of the LEDs’low power consumption.4. LEDs and indoor plant cultivation4.1. Plant tissue culture and growthTissue culture (TC), used widely in plant science and a number of commercial applications, is the growth of plant tissues or cells within a controlled environment, an ideal growth environment that is free from the contamination of microorganisms and other contaminants. A controlled environment for PTC usually means filtered air, steady temperature, stable light sources, and specially formulated growth media (such as broth or agar). Micropropagation, a form of plant tissue culture (PTC), is used widely in forestry and floriculture. It is also used for conserving rare or endangered plant species. Other uses of PTC include:1short-term testing of genetic constructions or regeneration oftrans genic plants,2 cross breeding distantly related species and regeneration of the novel hybrid,3 screening cells for advantageous characters (e.g. herbicidere sistance/tolerance),4embryo rescue (i.e. to cross-pollinate distantly related specie sand then tissue culture there sulting embryo which would normally die),5 large-scale growth of plant cells in liquid culture inside bioreactors as a source of secondary products (like recombinant proteins used as biopharmaceuticals).6production of doubled monoploid plants from haploid cultures to achieve homozygous lines more rapidly in breeding programs (usually by treatment with colchicine which causes doubling of the chromosome number).Tissue culture and growth room industries have long been using artificial light sources for production. These light sources include TFL, high pressure sodium lamp (HPS), metal halide lamp (MHL) and incandescent lamp, etc. Among them, TFL has been the most popular in tissue culture and growth room industries. However, the use of TFL consumes 65% of the total electricity in a tissue culture lab. That is the highest non-labor costs. As a result, these industries continuously seek for more efficient light sources. The development of high-brightness LED has made LED a promising light source for plant growth in controlled environments.Nhut et al. have cultured strawberry plantlets under different blue to red LED ratios as well as irradiation levels and compared its growth to that under plant growth fluorescent. The results suggest that a culture system using LED is advantageous for the micropropagation of strawberry plantlets. The study also demonstrates that the LED light source for in vitro culture of plantlets contributes to an improved growth of the plants in acclimatization.Brown et al. have measured the growth and dry matter partitioning of ‘Hungarian Wax’pepper (Capsicum annuum L.) plants grown under red LEDs compared with similar plants grown under red LEDs with supplemental blue or far-red radiation. Pepper biomass reduces when grown under red LEDs without blue wavelengths compared to plants grown under supplemental blue fluorescent lamps. The addition of far-red radiation results in taller plants with greater stem mass than red LEDs alone. Fewer leaves developed under red or red plus far-red radiation than with lamps producing blue wavelengths. The results of their research indicate that with proper combination of other wavelengths, red LEDs may be suitable for the culture of plants in tightly controlled environments.4.2. Space agricultureBecause re-supply is not an option, plants are the only options to generate enough food, water and oxygen to help make future explorers self-sufficient at space colonies on the moon, Mars or beyond. In order to use plants, there must be a light source. Standard light sources that used in homes and in greenhouses and in growth chambers for controlled agriculture here on Earth are not efficient enough for space travel. While a human expedition outside Earth orbit still might be years away, the space farming efforts are aimed at developing promising artificial light sources. LEDs, because of their safety, small mass and volume, wavelength specificity, and longevity, have long been proposed as a primary light source for space-base plant research chamber or bioregenerative life support systems .Infrared LEDs that are used in remote controls devices have other uses. Johnson et al. have irradiated oat (Avena sativa cv Seger) seedlings with infrared (IR) LED radiation passed through a visible-light-blocking filter. The irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. This suggests that the oat seedlings are able to detect IR LED radiation. These findings also expand the defined range of wavelengths involved in radiation–gravity (light–gravity) interactions to include wavelengths in the IR region of the spectrum.Goins et al. grow wheat under red LEDs and compare them to the wheat grown under (1) white fluorescent lamps and (2) red LEDs supplemented with blue light from blue fluorescent lamps. The results show that wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to those grown under white light. Wheat grown under red LEDs + 10% BF light had comparable shoot dry matter accumulation and seed yield relative to those grown under white light. These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.The research of Goins and his team continues in plant growth chambers the size of walk-in refrigerators with blue and red LEDs to grow salad plants such as lettuce and radishes. They hope the plant growth chamber would enable space station staff to grow and harvest salad greens, herbs and vegetables during typical fourmonth tours on the outpost .4.3. AlgacultureAlgaculture, refers to the farming of species of algae, has been a great source for feedstock, bioplastics, pharmaceuticals, algae fuel, pollution control, as well as dyes and colorants. Algaculture also provides hopeful future food sources.Algae can be grown in a photobioreactor (PBR), a bioreactor which incorporates some type of light source. A PBR is a closed system, as opposed to an open tank or pond. All essential nutrients must be introduced into the system to allow algae to grow and be cultivated. A PBR extends the growing season and allows growing more species. The device also allows the chosen species to stay dominant. A PBR can either be operated in ‘‘batch mode’’or ‘‘continuous mode’’in which a continuous stream of sterilized water that contains air, nutrients, and carbon dioxide is introduced. As the algae grows, excess culture overflows and is harvested.When the algae grow and multiply, they become so dense that they block light from reaching deeper into the water. As a result, light only penetrates the top 7–10 cm of the water in most algalcultivation systems. Algae only need about 1/10 the amount of direct sunlight. So, direct sunlight is often too strong for algae. A means of supplying light to algae at the right concentration is to place the light source in the system directly.Matthijs et al. have used LEDs as the sole light source in continuous culture of the green alga (Chlorella pyrenoidosa). The research found the light output of the LED panel in continuous operation sufficient to support maximal growth. Flash operation at 5-ps pulse ‘‘on’’ duration between dark periods of up to 45 ps would stillsustain near maximum growth. While longer dark periods tend to cut the growth rate, the light flux decrease resulting from such operation does not reduce the growth as much as that of the similar flux decrease in continuous operation. Their research concludes that the use of flashing LEDs (which means intermittent light) in indoor algal culture yielded a major gain in energy economy comparing to fluorescent light sources. An additional advantage is that heat waste losses are much smaller. The most interesting discovery of this study may be that adding blue light to the red LED light did not change the growth properties.In order to take advantage of the biotechnological potential of algae, Lee and Palsson have calculated theoretical values of gas mass transfer requirements and light intensity requirements to support high-density algal cultures for the 680 nm monochromatic red light from LED as a light source. They have also designed a prototype PBR based on these calculations. Using on-line ultra filtration to periodically provide fresh medium, these researchers have achieved a cell concentration of more than 2×109cells/ml (more than 6.6%, vol/vol), cell doubling times as low as 12 h, and an oxygen production rate as high as 10 mmol oxygen/l culture/h. This research indicates that the development of a small LED-based algal photobioreactors is economically achievable.Another research of algae via LEDs is conducted by Nedbal et al. Their research is a study of light fluctuation effects on a variety of algae in dilute cultures using arrays of red LEDs to provide intermittent and equivalent continuous light in small-size (30 ml) bioreactors. The results endorse that the algae growth rates in certain calculated intermittent light can be higher than the growth rate in the equivalent continuous light. Yanagi and Okamoto has grown five spinach plants under the red LEDs and another five under 40W plant growth fluorescent lamps at the same light intensity of 125 mmol/m2/s. The dry matter production under the LEDs is slightly less than that under the fluorescent lamps. The plant leaf area under the red LEDs is also smaller than that under the fluorescent lamps. Nevertheless, they reach a conclusion that LEDs can qualify as an artificial light source for plant growth.4.4.Plant disease reductionSchuerger and Brown have used LED arrays with different spectral qualities to determine the effects of light on the development of tomato mosaic virus (ToMV) in peppers and powdery mildew on cucumbers. Their research concludes that spectral quality may alter plant disease development. Latter research regarding bacterial wilt on tomato has confirmed this conclusion and demonstrates that spectral quality may be useful as a component of an integrated pest management program for space-based ecological life support systems. Schuerger et al. have shown that the spectral quality effects on peppers’ anatomical changes in stem and leaf tissues are corr elated to the amount of blue light in primary light source.Miyashita et al. use red LEDs (peak wavelength: 660 nm) and white fluorescent lamps as light sources for potato plantlets growth in vitro. They found that shoot length and chlorophyll concentration of the plantlets increases with increasing 630–690 nm red photon flux (R-PF) while there are no significant differences in dry weight and leaf area of the plantlets with different R-PF levels. This means red lightaffects the morphology rather than the growth rate of potato plantlets in vitro. As a result, they suggest that red LEDs can be used for controlling plantlet morphology in micropropagation.5. Intermittent and photoperiod lighting and energy savingTime constants for photosynthetic processes can be divided into three ranges: primary photochemistry, electron shuttling, and carbon metabolism. These three photosynthetic processes can be uncoupled by providing pulses of light within the appropriate range for each process. At high frequencies, pulsing light treatments can be used to separate the light reactions (light harvesting and charge separation) from the dark reactions (electron shuttling) of photosynthetic electron transport. LEDs’ flexible pulsating ability can be coupled with such characteristics of photosynthesis and lead to additional energy saving.Tennessen et al. use LEDs to study the effects of light pulses (micro- to milli-second) of intact tomato leaves. They found that when the equivalent of 50 mmol photons mp -2s-1 is provided during 1.5 ms pulses of 5000 mmol photons mp -2s-1 followed by 148.5 ms dark periods, photosynthesis is the same as in continuous 50 mmol photons mp -2s-1 . Data support the theory that photons in pulses of 100 ps or shorter are absorbed and stored in the reaction centers to be used in electron transport during the dark period. Pigments of the xanthophyll cycle were not affected by pulsed light treatments. This research suggests that, instead of continuous light, using effectively calculated intermittent light (which means less energy consumption) might not affect the plant production.Jao and Fang have investigated the effects of intermittent light on growth of potato plantlets in vitro. They also use conventional TFLs for the experiment to explore the electrical savings realized by adjusting the frequency and duty ratio of LEDs. TFLs provide continuous fluctuating light at 60 Hz while LEDs provide nonfluctuating light and pulse light of the preset frequency and duty ratio. When the growth rate is the only concern, LEDs at 720 Hz (1.4 ms) and 50% duty ratio with 16-h light/8-h dark photoperiod stimulated plant growth the most. When energy consumption is the major concern, using LEDs at 180 Hz (5.5 ms) and 50% duty ratio with 16-h light/8-h dark photoperiod would not significantly sacrifice plant growth, especially when energy for heat removal is also taken into account.6. ConclusionsThe first sustained work with LEDs as a source of plant lighting occurred in the mid-1980s when a lighting system for plant growth was designed for space shuttles and space stations for it is realized that people cannot go to the Moon, Mars, or beyond without first mastering the art of indoor farming on Earth. As the performance of LED continues to improve, these lighting systems progress from red only LED arrays using the limited components available to high-density, multi-color LED chip-on-board technologies. Today, space age gardeners who have been testing high-efficiency light sources for future space colonists have identified energy efficient LEDs as the major light source not only to grow food but also to generate and purify oxygen and water—key sustainers of human life. The removal of carbon dioxide from a closed environment is another added benefit.LEDs are the first light source to provide the capability of true spectral composition control, allowing wavelengths to match to plant photoreceptors to optimize production as well as to influence plant morphology and composition. They are easily integrated into digital control systems, facilitating complex lighting programs like varying spectral composition over the course of a photoperiod or with plant development stage. LEDs do not contain mercury. They are safer to operate than current lamps since they do not have glass envelopes or high touch temperatures.While the process of photosynthesis does not require continuous light of full spectrum, LEDs can produce sufficient photon fluxes of specific wavelength on and off rapidly. Such mechanism of photosynthesis coupled with the solid state characteristics of LEDs constitute two ways of energy saving (cutting out unnecessary spectrum segment and turning off the light periodically) on top of the LEDs’ low power consumption. These are not easily achievable with other light sources.This paper provides a broad base review on LED applications in horticulture industry since 1990. These researches pave the way for the researches of similar types using different species and lead to comparable conclusion that LEDs are well qualified to replace its more energy demanding counterparts as controlled environment light source for agricultural research such as providing tissue culture lighting as well as supplemental and photoperiod lighting for greenhouses.With the energy it can save, LED’s becoming ec onomically feasible in large-scale indoor farming lighting applications is just around the corner.再生可持续能源评论高亮高效节能LED灯的来源及其在室内植物栽培中的潜力摘要自1980年中期以来，光电子技术的迅猛发展，显著调高了发光二极管（LED）的亮度和效率。

LED显示屏外文翻译

附录3 中英文翻译The led manifestation holdThe LED manifestation hold(LED panel):The LED is a light emitting diode, give out light the English abbreviation of diode, brief name LED. It is 1 kind to passThe control semi-conductor give out light diode of manifestation way, it probably of appearance be from a lot of usually is red of the small light constitute, depend light of bright put out to manifestation character list. Using to the manifestation writing, sketch, picture, animation, condition of the market, video frequency and recording image signal's etc. is various manifestation screen of information.The LED manifestation hold to is divided into a diagram text's manifestation to hold with video frequency manifestation hold, is all constitute by LED matrix piece. The diagram text's manifestation hold can with calculator synchronous manifestation Chinese characters, English The text text origin and sketch，The video frequency manifestation hold adoption microcomputer to carry on control, diagram text, picture combine luxuriant, with solid hour, synchronous, clear information dissemination the way sow Putting various information, returning can manifestation two dimensions, 3D animation, record image, television, VCD program and the spot actual condition. The LED manifestation hold a manifestation an appearance color fresh and gorgeous, Stereoscopic the feeling be strong, quiet like oil painting, move like movie, extensive application in finance, tax administration, industry and business, post and tele, athletics, advertisement, factory mineral business enterprise, transportation, Teach system station, wharf, airport, market, hospital, guest house, bank, stock market, building market, sale line, industry business enterprise management and other public place.The LED's manifestation hold can manifestation variety of numeral, writing, sketch picture，Can not only used for an indoor environment but also used for outdoors environment, have to cast shadow an instrument, television wall, LCD manifestation to hold the advantage that can't compare to.The reason that, the LED be extensively valued but get quick development, is with it have of advantage inseparable. These advantages summarize BE，Bright degree Gao, work the electric voltage be low, achievement consume small and small scaled turn, life span long, bear pound at and function stability. The LED development foreground is extremely vast, currently just toward the higher and bright degree, higher bear weather, higherly give out light density and higherly give out light even, the credibility, whole color turn a direction development.the LED manifestation hold a development process 30 year review1970's at the earliest stage of GaP, GaAsP together quality knot red, Huang, green low give out light the LED of efficiency a beginning already application at the indicator, numeral and writing manifestation .From now on the LED start get into a variety application realm and include astronautics, airplane, car, industry application, correspondence, consume type product etc., all over each section of national economy and thousand 10000.To 1996 LED is in the whole world of sale sum already arrive several USD 1,000,000,000.Though the LED has been be subjected to a color and give out light therestriction of efficiency over several years, have a longevity life because of the GaP and the GaAsP LED, Gao credibility, work the electric current be small, can and TTL, CMOS numeral electric circuit and permit many advantage of etc. as a result has been be subjected to the green Mi of user. Recent decade, Gao Liang4 Du4 turn, whole color's turn has been being LED material and spare part craft technique research of front follow a topic. The extremely high and bright degree(UHB) is that give out light strength to attain or more than 100 mcd LED, call hole again virtuous pull(cd) class LED. Gao Liang4 Du4 the A1 GaInP and InGaN LED develop to make progress very quick, now already arrive normal regulations material GaA1 As, GaAsP, GaP impossible attain of function level.1991 Toshiba in Japan company and the United States the HP company develop into the InGaA1 P 620 nm an orange and extremely high and bright degree LED, 1992 the InGaA1 p 590 nm yellow extremely high and bright degree the LED be practical to turn At the same year, Toshiba company develop the InGaA1 P 573 nm Huang green an extremely high and bright degree LED, method to light as strong as 2 cd.1994 Japan day the second company develop into InGaN450 nm blue(green) color extremely high and bright degree LED. Go to this, color manifestation three Ji colors need be red, green, blue and orange, Huang variety the LED of the color all come to a hole virtuous pull give out light of class strength, realization the extremely high and bright degree turn, the whole color turn and make to give out light tube of outdoor whole color manifestation become reality. Our country development LED start in 70's, the industry appear in 80's.There is around more than 100 business enterprise in whole country, 95% factory house all be engaged in behind way pack produce, need tube Xin almost all from the abroad import. Pass the technique of a few "five years plan" reformation, the technique offend pass and usher in abroad forerunner equipments and parts of key technique, make our country LED of produce the technique have already step forward into one step.Two, extremely high and bright degree LED function:The extremely high and bright degree red A1 GaAsLED and GaAsP-GaP LED compare, have to higherly give out light an efficiency, the flow of transparent Chen low(TS) A1 GaAs LED(640 nm) clear efficiency already close 10 lm/w, ratio the red GaAsP-GaP LED big 1000%.Color and GaAsP-GaP that the extremely high and bright degree InGaAlP LED provide LED homology include，academy blue(560 nm), shallow academy blue(570 nm), yellow(585 nm), shallow Huang(590 nm),orange(605 nm) and pink(625 nm deep red.(640 nm)The transparent Chen bottom A1 GaInP LED give out light an efficiency and the other LED structure and white Chi light source of comparison, the InGaAlP LED absorb the flow of Chen bottom(AS) clear efficiency as 101 m/w, the transparent Chen bottom(TS) want to be 10 －s in height than the GaAsP-GaP flow of LED clear efficiency within the scope of the wave-length of 590 －626 nm for the 201 m/w 2000%;In 560 －s 570 wave-length scopes ratio GaAsP-GaP LED Gao Chu's 2 －s 400%.The extremely high and bright degree InGaN LED provided an orchid color light and green light, its wave-length scope orchid color is 450 －480 nm, orchid green is 500 nm, green is 520 nm，It flow the clear efficiency as 3 －151 m/ws. Extremely high and bright degree LEDcurrently flow a clear efficiency have already exceeded to take the incandescent lamp of color filter, can replace the power incandescent lamp within 1 w, and use a LED array can replace the power incandescent lamp within 150 w. For many application, all of incandescent lamps be an adoption color filter to get red, orange, green and orchid color, but use an extremely high and bright degree LED can then get homology of color. The extremely high and bright degree of the material and InGaN material manufacturing of the recent years AlGaInP LED many extremely high and bright degree LED chip combination together, need not color filter also ability get various color. Include red, orange, Huang, green and blue, currently its giving out light an efficiency all have already exceeded an incandescent lamp, is connecting toward the fluorescent lamp near. Give out light a bright degree Gao have already canned satisfy outdoors at the 1000 mcd all-weather, whole color manifestation of demand, use LED color big screen can performance the sky and ocean, realization 3D animation. The new generation red, green and blue and extremely high and bright degree LED come to an unprecedented function.Three, extremely high and bright degree LED application:rmation indicatorCar signal designation，car indicator's exterior in car's being main be a turn signal, tail lamp and brake light，Main is various appearance in the inner part of car of illuminate and manifestation. The extremely high and bright degree LED used for car indicator and the incandescent lamp of tradition to compare to have many advantage, in the car industry have extensive of market .The LED can experience a stronger machine to pound at and vibrate. Average work life span MTBF ratio incandescent lamp bubble Gao Chu Ji3 quantity class, far far Gao Chu's car of work life span, so flow bottom work, typical model of drive electric current an incandescent lamp to only at least have 12 red, yellow, blue green signal beacon.2.great screen manifestationGreat screen manifestation is extremely high and bright degree LED application of another one huge market, include，color and whole color of the monochrome, double of the sketch, writing, numeral manifestation. Tradition of the big screen have a source manifestation general adoption incandescent lamp, fiber optic, cathode ray tube etc.，Have no source manifestation general adoption turn over the method of card .Form 3 listed a few kinds manifestation of function comparison. The LED manifestation once had been be subjected to LED function and the restriction of the color .Now the extremely high and bright degree AlGaInP, TS-AlGaAs, InGaN LED have already can provide brightness of red, Huang, various green and blue color, can complete satisfy realization whole color big screen manifestation of request. LED manifestation hold can assemble into various structure according to the pixel size, figurine vegetable diameter general small at the 5 mm, monochrome manifestation of each pixel use a LED light of T-1(3/4), double color manifestation of each pixel is double the LED light of T-1(3/4) of the color, whole color manifestation demand 3T-1 be red, green, blue light, perhaps assemble much aer LED light of T-1(3/4) of chip be a pixel. The big pixel then pass pair of many T-1(3/4) red, green, the blue LED light combination together constitute e InGaN(480 nm) blue, InGaN's(515nm) being green be three Ji colors of LED manifestation with the ALGaAS(637 nm) red LED light, can provide a lifelike whole color function, and have bigger color scope to include: blue and green and green and red etc., with international television system committee(NTSC) provision of television color the scope be basic to agree with.3.the LCD manifestation(LCD) carry on the back to illuminateHave 10% adoption to have source light as to carry on the back illuminate atleast in the LCD manifestation, the light source can make LCD manifestation hold of dark of environment bottom easy read, whole color LCD manifestation also demand light source. The LCD carry on the back to illuminate the light source need main have，incandescent lamp bubble, field with the result that give out light, cold cathode fluorescence, LED etc., they be listed on form 4 carry on comparison, among them,the LED have a competition ability most in the LCD carry on the back the lighting,the new extremely high and bright degree AlGaInP, AlGaAs, InGaN LED can provide to high-efficiencily give out light with the color of breadth scope.The LED used for LCD to carry on the back to illuminate main have three kinds of way.(1)Most simple is LED light direct install spread to shoot a film in the LCD of behind, can use many pack of LED light, they should have very breadth of light beam Cape with make stalk to light the even be better. Can also adoption don't pack of tube Xin, general use GaP LED, however use AlGaInP, TS-AlGaAs LED can then under the small electric current work, let up achievement consume.(2)Another a way are an edge light the LCD carry on the back illuminate and use a transparent or translucent rectangle plastics a piece conduct and actions lead light body, is direct it install to spread to shoot a film in the LCD of behind, plastics piece of empress surface Tu2 Shang4 white reflection material, LED light shoot from a flank of plastics piece go into, rest the flank make with white reflection material.(3)LED send out of light ducting fiber optic bunch in, fiber optic bunch of spread and shoot film behind constitute a flat of thin slice, can use dissimilarity of method's taking out from the thin slice the light be a carry on the back of LCD illuminate .Adoption LED conduct and actions carry on the back illuminate of the liquid crystal display can used for ambulation telephone, notebook, along with the small scaled liquid crystal display isin the stanza the electricity the type the correspondence the product of extensive usage, will have greater need to the extremely high and bright degree LED.4.the solid shine on a lightWhole color extremely high and bright degree LED of practical turn with commercialize, make to illuminate a technique to face a new of revolution, solid floodlight make into by many extremely high and bright degree red, blue and green three color LEDses not only can send out a wave-length continuous various adjustable color light, and also can send out a bright degree can reach several 10-100 candlelights of white become lighting light source .Recen Japan day second company make use of its InGaN be blue light LED and fluorescence technique, again released white light the solid give out light a spare part product, its color is 6500 K, the efficiency reach each tile 7.5 flow clear .For homology give out light incandescent lamp and LED solid floodlight of bright degree to say, the achievement of the latterconsume a have the former of 10% －be 20% and the life span of the incandescent lamp's being general be not over 2000 hours, but the life span of the LED light be as long as tens of thousands hours. This kind of physical volume is small, the weight be light and directive good, economy energy, life span long, bear various bad condition of solid light source necessarily will to tradition of the light source market result in pound at. Though this kind of is new to illuminate the cost of solid light source still higher, can application like mineral mountain at some special situation, dive, rob insurance, for use by the military equip of illuminate etc From farsighted see, if the LED the further extension of the production scale of the extremely high and bright degree, cost further lower, it at economy energy and longevity life of the advantage is good enough to make up its price higher bad situation .The extremely high and bright degree LED will probably become a kind of new lightning source which have much of a competition ability.LED显示屏LED显示屏：LED就是light emitting diode ，发光二极管的英文缩写，简称LED。

LED电子显示屏毕业设计中英文翻译

中文：LED电子显示屏在酒店休闲场所中的应用随着显示器件与技术的进一步发展，屏幕显示系统在国民经济中得到了广泛的应用，LED显示屏是信息显示的重要传媒之一。

LED显示屏是利用发光二极管点阵模块或像素单元组成的显示屏幕。

伴随着计算机技术的发展，使得LED数码管能够在减少驱动器的情况下能够直接被驱动。

而且它具有可靠性高、使用寿命长、性能价格比高、使用成本低、环境适应能力强等特点，所以一直在平板显示领域扮演着重要的角色，并且在今后相当长的一段时期内还有相当大的发展空间。

所以被广泛应用于金融市场、医院、体育场馆、机场、码头、车站、高速公路等公共场所的信息显示和广告宣传。

近几年来我国LED显示的相关技术也取得了较快和较大的发展，早期时曾因LED材料器件的限制，LED显示屏的应用领域没有广泛展开，另一方面，显示屏控制技术基本上是通信控制方式，客观上影响了显示效果。

所以导致早期的LED显示屏在国内很少，产品以红、绿双基色为主，控制方式为通信控制，灰度等级为单点四级调灰，产品的成本比较高。

后来LED显示屏迅速发展，进入九十年代，全球信息产业高速增长，信息技术各个领域不断突破，LED显示屏在LED材料和控制技术方面也不断出现新的成果。

蓝色LED镜片研制成功，全彩色LED显示屏进入市场;电子计算机及微电子领域的技术发展，在显示屏控制技术领域出现了视频控制技术，显示屏的动态显示效果大大提高。

这个阶段，LED显示屏在我国发展迅速，LED显示屏产业成为新兴的高科技产业。

今天，LED显示屏应用领域更为广阔，下面我就来谈谈 LED 在酒店和休闲场中的应用。

一、酒店LED显示屏的效益LED电子显示屏被誉为继电视,报纸,网络之后的第四大广告宣传媒体，它能给投资者带来看得见的社会效益及经济效益，LED电子显示屏可接收来自计算机、电视机、录像机、VCD、摄像机等传输的信息，并实时播放二维或三维动画、文字资料。

随着经济的发展，社会工作生活的节奏的加快，酒店在人们的生活中伴影着一个不可缺少的角色。

激光专业知识英语作文

激光专业知识英语作文英文：Laser technology is a fascinating field that has revolutionized many industries. As a laser professional, I have gained a lot of knowledge about the principles and applications of lasers.Firstly, lasers work by emitting a coherent beam of light that is highly concentrated and focused. This makes them ideal for precision cutting, welding, and drilling in industries such as manufacturing and construction. They are also used in medical procedures such as eye surgery and tattoo removal.Secondly, there are different types of lasers, each with its unique properties. For example, gas lasers such as carbon dioxide (CO2) lasers are commonly used in industrial applications, while solid-state lasers such as neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers are used inmedical procedures. Fiber lasers are also gainingpopularity due to their high efficiency and low maintenance costs.Lastly, laser safety is a crucial aspect of laser technology. It is essential to follow safety protocols and wear protective gear such as goggles and gloves whenworking with lasers. Failure to do so can result in serious injuries such as burns and eye damage.In conclusion, laser technology is a fascinating field with many applications and safety considerations. As alaser professional, I am constantly learning about new developments and advancements in the field.中文：激光技术是一个迷人的领域，已经彻底改变了许多行业。

毕设英文翻译

High-resolution Fourier lens designSong Gu, Chunyu Liu, Guang Jin Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences Changchun, China gusongl26@, mmliucy@ jing@ Chunyu Liu Graduate University of Chinese Academy of Sciences Beijing, China mmliucv@,l 63 .comAbstract—This Fourier lens system is often used in optical signal processing system. Based on the design principles of Fourier lens system and the requirements of some particles observation experiment, a Fourier optical system whose working wavelength was 532nm was designed using ZEMAX. The testing experiment using the visual microscope, showed that the system's resolution was 2501p/mm. And the system was successfully used in the particles observation experiment.Keywords- Fourier lens system; optical design; Optic information processingI. INTRODUCTIONFourier lens system is widely used in optical information processing, such as image conversion and transmission, spatial filtering, holography, holographic storage in the Fourier, because of its diffraction field is the Fourier spectrum of surface-screen function , you can use the natureof the Fourier transform lens, through the Change the spectrum to transform the image information processing. For example, place the filter in the spectrum plane can inhibit high-frequency noise and limited bandwidth, low-frequency signals without attenuation. Using Fourier lens system you can transform the image of the flow field and particle field which are difficult to measure directly. This paper describes a particle field for recording high-resolution large face of the Fourier lens system design.II. DESIGN PRINCIPLESFourier lens designed have to comply with following principles: first, Fourier lens design requires to control aberrations on two pairs of conjugate position. The object of the first conjugate position is the diffraction parallel light, the imaging plane corresponding to the spectrum plane; The second conjugate position of the object-image is the input plane as the object, the corresponding image at infinity. Therefore, To control aberrations of the conjugate position, both need to control the object surface, but also need to control the optical path aberration. Second, the Fourier transform lens must satisfy the sine condition. Third, the Fourier system are generally used in coherent light, so dust, scratches, bubbles and other defects which might cause strong coherent noise and the system can also cause stray light in the noise, this effect increases with the number of pieces have become the lens Serious. Therefore, the design should minimize the number of lensesIII. THE INITIAL STRUCTURE DESIGNAccording to the needs of measuring field particles, the object field of view as®80mm, the system was like a ratio of 1:1, the working wavelength of 532 nm, resolution is better than 4um. Because of the system is a no optical power system, the first group and the back group of System after are completely symmetrical, Therefore only need to consider the design of the back group. To design the back group, first consider of the simplest structure that can correct all the aberrations, that is, three-piece lens structure. It has eight variables, namely, the radius of curvature and two intervalsof six, just seven aberration correction and focal length to meet the requirements of the total. Solving the half-step structure to simplify all the operations. On the half-step structure, there:Where: Selected glass combination , using the above formula to solve the SIV on the n, v, and the expression of h2. When the chromatic aberration does not exist, Cl = 0, optical power is:However, you can handle and a spout (7) and (8) as the independent equations to solve w2 and h2. At the same time so that you can find the correct spherical aberration and astigmatism of the h2 and w2 to h2 as independent variables obtained by using the same sequential approach w2, and then can be from (4) Find Ol, O 2, d, and calculate the SIV. Calculated through a series of combinations of glass, the glass can also be seen on the correct combination of SIV in the best interests of the glass, the relation between w2 and Q2is:Combine the two symmetrical half of the three objectives. On this basis, in order to better senior aberration correction, to obtain the three-piece structure is farther complicated, in a compact structure to achieve diffraction limited performance. And further reduce the aperture to the mirror group distance, and thus shorten the tube length optical systems. The structure optimized by Zemax is shown in Figure 3 after the group.IV. DESIGN RESULTS AND IMAGE QUALITY EV ALUA TIONThe optical system is designed and optimized using Zemax.The structure type is shown in Figure4. A group of flat glass is added to first group system according to user's requirements. Therefore, changing the contribution of axisaberrations by optimizing the optical system, a full symmetry system is achieved, and it is conducive to improving the processing and reliability. Optical transfer fiinction of an optical system of the main evaluation tools, the optical system transfer function (MTF) as shown in Figure (5) below:Design transfer function curve shows the diffraction limit has been reached. The system have made good quality image was achieved in all the field. The above analysis shows that the lens image quality is excellent. The system designed meets the actual requirements.V. TEST RESULTSTo verify if the 4F system can meet the requirements of particle testing, the method of microscope method is applied. The testing equipment is shown in Fig. 8. After testing, the system can easily see the No. 1 plate number identification rate of 25 units, corresponding to a resolution of 250LP/mm.VI. CONCLUSIONA Fourier lens system for particle observation is designed according to the basic principle of Fourier optical. The working wave length of the system is 532nm and 694nm. Complication design method of "TRIPLER" is applied to meet the system's requirements. Through theoreticalcalculation and optimization of ZEMAX, we made a good correction for off-axis astigmatism, spherical aberration and distortion. Test results show that the system resolution reached 2501p/mm and the system has good aberration correction. Mounting a CCD or holographic system behind the proposed system can make the real time observation of micro particle possible and provide a way for observing the particle field hard to measure directly. The design has high application value in fields like optical information processing, etc. The results of the research also have reference significance in design and research of other types of high resolution Fourier lens system.[1] An Baoqing, Xiangli Bin, Gao Zhan, Xue Mingqiu, "Study on Precise Symmetric Fourier Transform Lens," Acta Photonica Sinica, V ol. 26, Otc. 1997, pp. 956-959. [2] Ji Y anfeng, He Shurong, He Qingsheng, Wu Minxian, Jin Guofan, "Design of Fourier transform lenses in VHDSS," Optical Technique, V ol. 30, Jan. 2004, pp. 17-19 [3] Lv Xiankui, "Design of Large Aperture Monochromatic Fourier Transform Lens," Master Dissertation of Chongqing University, May. 2005.[4] Lv Li, "Design of Fourier transform lens," Dissertation submitted to Chongqing University for Master Degree of Engineering, May. 2003.[5] Yin Wei, "Design of Fourier Transform Lens," A Thesis Submitted to Chongqing University in Partial Fulfillment of the Requirement for the Degree of Master of Engineering, April. 2009.高分辨率傅里叶透镜设计Gu Song , Liu Chunyu, Jin Guang1.中国科学院长春光学精密机械与物理研究所2. 中国科学院研究生院,北京摘要：傅立叶透镜系统广泛的应用于光信号处理系统中。

电子科学与技术毕业论文英文外文文献翻译

毕业设计（论文）外文文献翻译AbstractThis paper presents a voltage compensation driver for lighting a passive matrix organic LEDs (PMOLEDs) panel. A driver is designed andfabricated using FPGA and discrete components. The supply voltage range of the proposed driver is under 20V. Therefore, it can be applied in most commercial PMOLEDs panels. The luminance is confirmed by driving a PMOLEDs panel with a size of 64*48 pixels. Experimental results indicate that good luminance uniJormiQ is achieved using the proposed compensation driver. The lighting performance of PMOLEDs is quite similar to that driven by a canstant current. The voltage compensation driving method is applicable to PMOLEDs panels with various struciures or materials. Moreover, it can be applied to both monochrome and gray scale PMOLEDs Panels.Index Terms --eonstant current, luminance uniformity PMOLEDs, voltage compensation.I. INTRODUCTIONlat panel displays are in the mainstream of the information Fdisplay; they include a TFT-LCD monitor. The Organic LEDs (OLEDs) panel is another technology developed during the past decade. The OLEDs panels have several excellent and unique characteristics [I]. The properties include a wide viewing angle, quick response, thinness, lightness, , high efficiency, and self-emission [2]. Many studies have developed improved structures for PMOLEDs panels to enhance the lifetime and photo-efficiency [3]-[7]. Technologies for massproducing OLEDs are showing continuous advancement. Consequently, OLEDs technology may be applied extensively to commercial products in the near future.Applications of OLEDs technology include the following [SI.1 : lnformation systems2: Back lighting for LCD3: Automotive lighting4: Advertising panels5: Light sources6: Airport runway lighting7: Car audio lighting8: PDA / PC displays9: Smart cardsIO: Cellular phones'Chang-Jung Juan and Ming-long Tsai are with the Graduate SFhool of Engineenng, National Taiwan University of Science and Technology, No. 43,Sec. 4, KeeLung Rd., Taipei, 106, Taiwan, R.O.C.(mjtsai@.tw) Chang-Jung Juan is also with ElectronicEngineering Department, Hwa-Hsia College of Technology and Commerc6,No. 111, Hwa-Sing St., Jong-He ciw, Taipei, 243, Taiwan. R.O.C.(rric@.t~,)OLEDs panels can be classified into two types active matrix OLEDs (AMOLEDs) and passive OLEDs (PMOLEDs) [2]. Each individual pixel inside an AMOLEDs panel is independently driven via associated TFTs and capacitors in the electronic hack plane, as shown in Fig. I(a). In contrast, each pixel inside a PMOLEDs panel is lit by the driver, attached to each row and column, as shown in Fig. l(b). When a particular row is chosen, the column data and the row determine the lit pixels.PMOLEDs panels have been used in some commercialized products, including mobile phones and carstereos. With the aforementioned superior characteristics and possible applications, the OLEDs panel could be a significant mainstream technology in the display field in the future [9].The luminance of the PMOLEDs is linearly related to the current fed into the pixel. Naturally, the current controls the brightness of a PMOLEDs panel. A constantcurrent method is the most popular method for driving a PMOLEDs panel. This topic has been discussed in several papers [IO]-[14]. A current control theory is applied to a closed loop system that implies the circuit with a feedback path. A complex circuit generates a constant current. Thus, oscillation problems and the response time of a driving current should be considered.In PMOLEDs panels, indium-tin-oxide (ITO) is connected to the anode of each pixel in a column. In each row, a metal line is connected to the cathode of each pixel, as illustrated in Fig. l(b). The resistance of the IT0 is approximately 80 n /square area. The IT0 serves as a conductor so resistances exist between each pixel in the same column. Figure 2(a) presents a partial circuit of a singlecolumn in the PMOLEDs, where Re represents the resistance of the ITO. Accordingly, the IT0 resistance causes a voltage drop so that each pixel in each different row has a different voltage drop. Figure 2(b) illustrates the voltage drop for two pixels, p (I,]) and p (k, 1) in row one and row k, respectively. The resistances can be witten as R (1,l) and R (k,l), respectively. The relationship between- these two resistances can be described by the following equation.(1)Equation (1) .implies that the resistance of a pixel depends on the length of the ITO. Assume that the voltage drop due to the IT0 resistance can he compensated for a uniform luminance can be obtained by a voltage-driven PMOLEDs panel.11. PRINCIPLE OF VOLTAGE COMPENSATIONIn this section, the replacement by voltage compensation of a constant current driver for lighting a PMOLEDs panel is proven. Generally, a current controlled circuit drives a PMOLEDs panel. The gray level luminance of a PMOLEDs panel can be easily controlled. However, a totally different method, involving a voltage compensation driver, is proposed. Advantages of the proposed driver include ease of fabrication and quick electronic responses in operation. Furthermore, the^ display performance of a voltage compensation driver is sufficiently good in displaying mono-color pictures. Consider a PMOLEDs panel with a size of 3*3 pixels. Figure 3 presents the equivalent circuitry. Notably, the anode ofeach pixel is connected to each column from an IT0 and the cathode of each pixel is connected to a row by way of metal; The effect of capacitance can be neglected in the steady staie: The resistances of IT0 and metal are the major factors that affect the luminance. They are the resistance of the column (Rc) and the resistance of the row (Rr), respectively.Assuming that a pixel in the first column and the first row on a PMOLEDs panel is represented by P (0,O). The overall resistance will he Rc + Rr. It can be generally rewritten asFollows.where "i" is the row number and '7' is the column number.Equation (2) presents an important property of a PMOLEDs panel. The line resistance of each pixel differs from that of !he others in a PMOLEDs panel. The voltage compensation method is based on the standard procedure for producing a PMOLEDs panel. Accordingly, each pixel has the same characteristics, 'except line resistance. If the line resistance is ignored, the measured voltage drop across each pixel will he the same when the PMOLEDs panel is driven by a constant current.111. HARDWAREIM PLEMENTATIONThis section describes a voltage compensation method based on the principles derived from Section 11. Recall that the uniform luminance of a PMOLEDs panel can be obtained when each pixel is maintained at the same driving voltage and the line resistance is not a factor. Equation (7) can he transferred by an analog adder from hardware perspective. This adder manipulates three items - V(O,O), A V, (j) and A Vx (i) . Software-controlled DAC (Digital to Analog Converter) can generate varying voltages A Vc&) and A VR(i). Generally, lighting on a PMOLEDs panel is scanned row by row; thus, data for displaying in each column were passed simultaneously. Each column driver requires a DAC to compensate for the voltage A Vc. Such a circuit would he very complex and costly. Therefore, consider A V, (j). It is in the V range, and is not very important in the uniformity of luminance; hence, A V,(j) can be neglected for simplicity the circuit. VO,ED,i, = V(O,O)+ A V, 6) ( 8 ) where i is the row number The simplified Eq. (8) can be implemented using a DAC and a look up table (LUT), as shown in Fig. 5. The input to LUT is a row number and its outputs aredigital data to be input to a DAC, so that the varying voltage across^ the row, A V,(i). is generated. A counter is used to generate the row number. The counter is triggered by a synchronization of horizontal line (H.S.) and is reset by a frame vertical synchronization (V.S.). When lighting a PMOLEDs panel, the driver can generate a voltage, which is a function of a row number, to achieve a uniform luminance.Iv. EXPERIMENTRAELS ULTSA ND DISCUSSIONIn this section, some experimental results are presented to prove why the voltage compensation method can be applied to PMOLEDs panels to yield a uniform brightness. Figure 8shows a verifying system that combines a PMOLEDs panel and a power source with accurate measurement instruments to evaluate the compensation method for a PMOLEDs panel. The specification of a PMOLEDs panel is 64*48 pixels and the anode is made of ITO; the cathode is made of a metal line. A PC acts as a data collector and a controller during the testing procedure. A constant current flows through each pixel in the PMOLEDs panel. Meanwhile, the voltage drop across each pixel of PMOLEDs panel is recorded. Table I lists the voltage drops at different locations of a PMOLEDs panel at a constant current of 500~4. These voltage drop data clearly indicate that the resistance of the anode is key in the luminance performance of lighting a PMOLEDs panel. Accordingly, Eq. (7) gives the resistance of the anode. The voltage across different rows can thus be compensated for, to achieve uniform luminance when lighting a PMOLEDs panel.V. CONCLUSIONThis paper describes a voltage compensation method for improving the luminance uniform& of a PMOLEDs panel to take the place of a current-type driving method. The paper Chang-Jung Juan was born in considered basic theories and the circuit design of a voltage- Taiwan, R.O.C. in 1961. He compensated driver. Experimentalresults indicate that the received the B.S. and M.S. degree‘ luminance uniformity performance of the voltage in Electrical Engineering from compensation driving method is similar to that obtained by a National Taiwan Institute of constant current driving method. The proposed voltage- Technology, Taipei, Taiwan, R.O.C. compensated driver can be applied to both monochrome and in 1987 and 1989 respectively. gray scale PMOLEDs panels. Furthermore, the proposed Since 1989, he has been a faculty driver is economical than the conventional driver, member of the Department of Electronics Engineering of Hwa because of simple circuitry.介绍本文提出了一个电压补偿驱动被动矩阵有机发光二极管（PMOLEDs）面板照明。

外文文献--翻译--led显示屏

外文资料原文Large screen display system’s researchLed developmentAlong with computer technology’s high speed development，LED （Light Emitting Diode) the screen display system takes after the television, the broadcast, the newspaper, the magazine “the fifth big media” marches into the social life fast each aspect。

Its collection microelectronic technology, the computer technology, the information processing and management technology in a body, may the information through the writing, the design，the animation and the video frequency four forms demonstrates. With media and so on bank of television monitors，magnetism vane compares，the LED large screen display system has the design to be artistic，the color is sharp; The design，the color change are rich，are fast; The low power loss，the long life, the use cost low, work stably reliable and so on characteristics。

光电系毕业论文外文翻译半导体激光器适用于毕业论文外文翻译+

毕业设计（论文）英文翻译姓名学号０８１１１２２１２１所在学院理学院专业班级２００８级光信１班指导教师日期２０１２年４月２０日英文原文1.5 Experimental Setup Due to the many concepts and variations involved in performing the experimentsin this project and also because of their introductory nature Project 1 will very likelybe the most time consuming project in this kit. This project may require as much as 9hours to complete. We recommend that you perform the experiments in two or morelaboratory sessions. For example power and astigmatic distance characteristics maybe examined in the first session and the last two experiments frequency andamplitude characteristics may be performed in the second session. A Note of Caution All of the above comments refer to single-mode operation of the laser which is avery fragile device with respect to reflections and operating point. One must ensurethat before performing measurements the laser is indeed operating single-mode.This can be realized if a single broad fringe pattern is obtained or equivalently a goodsinusoidal output is obtained from the Michelson interferometer as the path imbalanceis scanned. If this is not the case the laser is probably operating multimode and itscurrent should be adjusted. If single-mode operation cannot be achieved by adjustingthe current then reflections may be driving the laser multimode in which case thesetup should be adjusted to minimize reflections. If still not operating single-modethe laser diode may have been damaged and may need to be replaced. Warning The lasers provided in this project kit emit invisible radiation that can damagethe human eye. It is essential that you avoid direct eye exposure to the laser beam.We recommend the use of protective eyewear designed for use at the laser wavelengthof 780 nm. Read the Safety sections in the Laser Diode Driver Operating Manual and in thelaser diode section of Component Handling and Assembly Appendix A beforeproceeding.1.5.1 Semiconductor Diode Laser Power Characteristics1. Assemble the laser mount assembly LMA-I and connect the laser to its powersupply. We will first collimate the light beam. Connect the laser beam to a videomonitor and image the laser beam on a white sheet of paper held about two to tencentimeters from the laser assembly. Slowly increase the drive current to the laser andobserve the spot on the white card. The threshold drive current rating of the laser issupplied with each laser. Increase the current to about 10-20 mA over the thresholdvalue. With the infrared imager or infrared sensor card observe the spot on the card andadjust the collimator lens position in the laser assembly LMA-I to obtain a bright spoton the card. Move the card to about 30 to 60 centimeters from the lens and adjust thelens position relative to the laser to obtain a spot where size does not vary stronglywith the position of the white card. When the spot size remains roughly constant asthe card is moved closer or further from the laser the output can be consideredcollimated. Alternatively the laser beam may be collimated by focusing it at adistance as far away as possible. Protect fellow co-workers from accidental exposureto the laser beam.2. Place an 818-SL detector on a post mount assembly M818 and adjust its positionso that its active area is in the center of the beam. There should be adequate opticalpower falling on the detector to get a strong signal. Connect the photodetector to thepower meter 815. Reduce the background lighting room lights so that the signalbeing detected is only from the laser. Reduce the drive current to a few milliamperesbelow threshold and again check to see that room light is not the dominantsignal atthe detector by blocking the laser light.3. Increase the current and record the output of the detector as a function of laser drivecurrent. You should obtain a curve similar to Figure 1.2. If desired the diodetemperature may also be varied to observe the effects of temperature on thresholdcurrent. When examining laser diode temperature characteristics the laser diodedriver should be operated in the constant current mode as a safeguard againstexcessive currents that damage the diode laser. Note that as the diode temperature isreduced the threshold decreases. Start all measurements with the diode current off toprevent damage to the laser by preventing drive currents too high above threshold.To prevent destruction of the laser do not exceed the stated maximum drive current ofthe laser.1.5.2 Astigmatic Distance Characteristics The laser diode astigmatic distance is determined as follows. A lens is used tofocus the laser beam at a convenient distance. A razor blade is then incrementallymoved across the beam to obtain data for total optical power passing the razor edge vs.the razor blade position. A plot of this data produces an integrated power profile of thelaser beam Figure 1.9a which through differentiation exposes the actual powerprofile Figure 1.9b which in turn permits determination of the beam diameter W.A beam diameter profile is obtained by measuring the beam diameter while varyingthe laser position. Figure 1.9c illustrates the two beam diameter profiles of interest:one for razor edge travel in the direction perpendicular to the laser diode junctionplane and the other for travel in the direction parallel to the junction plane. Theastigmatic distance for a laser diode is the displacement between the minima of thesetwo profiles. This method is known as the knife edge technique.1. Assemble the components shown in Figure 1.8 with the collimator lens LC in therotational stage assembly RSA-I placed roughly 1 centimeter away from the laser.The beam should travel along the optic axis of the lens. This is the same lens used incollimating the laser in the previous setup. The approximate placement of all thecomponents are shown in the figure. Make sure that the plane of the diode junctionxz plane in Figure 1.1 is parallel with the table surface.2. Due to the asymmetric divergence of the light the cross-section of the beamleaving the laser and further past the spherical lens is elliptical. The beam thus hastwo distinct focal points one in the plane parallel and the other in the planeperpendicular to the laser diode junction. There is a point between the two focalpoints where the beam cross-section is circular. With the infrared imager and a whitecard roughly determine the position where the beam cross-section is circular. Figure 1.9 – Procedure for finding astigmatic distance.3. Adjust the laser diode to lens distance such that the razor blades are located in thexy plane where the beam cross-section is circular.4. Move the laser diode away from the lens until minimum beam waist is reached atthe plane of razor blades. Now move the laser diode about 200 m further away fromthe lens.5. Move razor blade 1 in the x direction across the beam through the beam spreadθxand record the x position and detected intensity at each increment ≤100 mincrements. The expected output is shown in Figure 1.9. The derivative of this curveyields the intensity profile of the beam in the x direction from which the beamdiameter is determined.6. Repeat with razor blade 2 for θy in the y direction.7. Move the laser closer to the lens in increments ≤50 m through a total of at leastthan 500m. Repeat Steps 5 and 6 at each z increment recording the z position.8. Using the collected data determine the beam intensity profiles in the x and ydirections as a function of the lens position z. This is done by differentiating each dataset with respect to position. Then calculate the beam diameter and plot as a functionof z. The difference in z for the minimum in θx and θy isthe astigmatic distance of thelaser diode. Use of computer software especially in differentiating the data is highlyrecommended. If the laser junction is not parallel to the table surface then for eachmeasurement above you will obtain an admixture of the two beam divergences andthe measurement will become imprecise. If the laser is oriented at 45° to the surfaceof the table the astigmatic distance will be zero. Different laser structures will have different angular beam divergences and thusdifferent astigmatic distances. If you have access to several different laser types gainguided index guided it may be instructive to characterize their astigmatic distances.1.5.3 Frequency Characteristics of Diode Lasers In order to study frequency characteristics of a diode laser we will employ aMichelson interferometer to convert frequency variations into intensity variations. Anexperimental setup for examining frequency and also amplitude characteristics of alaser source is illustrated in Figure 1.10.1. In this experiment it is very possible that light may be coupled back into the laserthereby destabilizing it. An optical isolator therefore will be required to minimizefeedback into the laser. A simple isolator will be constructed using a polarizing beamsplitter cube and a quarterwave plate. We orient the quarterwave plate such that thelinearly polarized light from the polarizer is incident at 45° to the principal axes of thequarterwave plate so that light emerging from the quarterwave plate is circularlypolarized. Reflections change left-circular polarized light into right-circular or viceversa so that reflected light returning through the quarterwave plate will be linearlypolarized and 90° rotated with respect to the polarizer transmission axis. The polarizerthen greatly attenuates the return beam. In assembling the isolator make sure that the laser junction xz plane in Figure1.1 is parallel to the surface of the table the notch on the laser diode case pointsupward and the beam is collimated by the lens. The laser beam should be parallel tothe surface of the optical table. Set the polarizer and quarterwave λ/4 plate in place.Place a mirror after the λ/4 plate and rotate the λ/4 pl ate so that maximum rejectedsignal is obtained from the rejection port of the polarizing beam splitter cube asshown in Figure 1.11. When this signal is maximized the feedback to the laser shouldbe at a minimum.2. Construct the Michelson interferometer as shown in Figure 1.12. Place the beamsteering assembly BSA-II on the optical table and use the reflected beam from themirror to adjust the quarterwave plate orientation. Set the cube mount CM on theoptical breadboard place a double sided piece of adhesive tape on the mount and putthe nonpolarizing beam splitter cube 05BC16NP.6 on the adhesive tape. Next placethe other beam steering assembly BSA-I and the detector mountM818BB inlocation and adjust the mirrors so that the beams reflected from the two mirrorsoverlap at the detector. When long path length measurements are made the interferometer signal willdecrease or disappear if the laser coherence length is less than the two wayinterferometer path imbalance. If this is the case shorten the interferometer until thesignal reappears. If this does not work then check the laser for single-mode operationby looking for the fringe pattern on a card or by scanning the piezoelectric transducerblock PZBin BSA-II and monitoring the detector output which should be sinusoidalwith PZB scan distance. If the laser does not appear to be operatingsingle-moderealign the isolator and/or change the laser operating point by varying the bias current.Additionally to ensure single-mode operation the laser should be DC biased abovethreshold before applying AC modulation. Overdriving the laser can also force it intomultimode operation.3. The Michelson interferometer has the property that depending on the position of themirrors light may strongly couple back toward the laserinput port. In order to furtherreduce the feed-back slightly tilt the mirrors as illustrated in Figure 1.13. If stillunable to obtain single-mode operation replace the laser diode.4. Place a white card in front of the detector and observe the fringe pattern with theinfrared imager. Slightly adjust the mirrors to obtain the best fringe pattern. Try toobtain one broad fringe.5. Position the detector at the center of the fringe pattern so that it intercepts no morethan a portion of the centered peak.6. By applying a voltage to the piezoelectric transducer block attached to the mirrorpart PZB in one arm of the interferometer i.e. BSA-II maximize the outputintensity. The output should be stable over a time period of a minute or so. If it is notverify that all components are rigidly mounted. If they are then room air currents maybe destabilizing the setup. In this case place a box cardboard will do over the setupto prevent air currents from disturbing the interferometer setup.7. Place the interferometer in quadrature point of maximum sensitivity betweenmaximum and minimum outputs of the interferometer by varying the voltage on thePZB.8. The output signal of the interferometer due to frequency shifting of the laser isgiven by I∝φ 2π/c L ν where L is the difference in path length b etween thetwo arms of the interferometer and ν is the frequency sweep of the laser that isinduced by applying a current modulation. Remember that in a Michelsoninterferometer L is twice the physical difference in length between the arms sincelight traverses this length difference in both directions. L values of 3-20 cmrepresent convenient length differences with the larger L yielding higher outputsignals. Before we apply a current modulation to the laser note that the interferometeroutput signal I should be made larger than the detector or laser noise levels byproper choice of L and current modulation amplitude di. Also recall from Section1.3that when the diode current is modulated so is the laser intensity as well as itsfrequency. We can measure the laser intensity modulation by blocking one arm of theinterferometer. This eliminates interference and enables measurement of the intensitymodulation depth. We then subtract this value from the total interferometer output todetermine the true dI/di due to frequency modulation. Apply a low frequency smallcurrent modulation to the laser diode. Note that when the proper range is beingobserved 1 dv 10 5 mA 1 v diand 1 dI 0.2mA 1 I difor the amplitude change only.RecallingdI d（Δφ）2π Δv c dI ∝ΔL 10 5 mA 1 di di cΔi 2πΔLv diordI ΔL 2Kπ mA 1di λ10 -5where K is a detector response constant determined by varying L.9. With the interferometer and detection system properly adjusted vary the drivefrequency of the laser and obtain the frequency response of the laser Figure 1.4 or1.10a.You will need to record two sets of data: i the modulation depth of theinterferometer output as a function of frequency and ii the laser intensitymodulation depth. The difference of the two sets of collected data will provide anestimate of the actual dI/di due to frequency modulation. Also note that if the currentmodulation is sufficiently small and the path mismatch sufficiently large the laserintensity modulation may be negligible. You may need to actively keep theinterferometer in quadrature by adjusting the PZB voltage. Make any necessary function generator amplitude adjustments to keep thecurrent modulation depth of the laser constant as you vary the frequency. This isbecause the function generator/driver combination may not have a flat frequencyresponse. The effect of this is that the current modulation depth di is not constant andvaries with frequency. So to avoid unnecessary calculations monitor the current.。

激光外文文献翻译+参考文献论文

激光外文文献翻译+参考文献-论文激光外文文献翻译+参考文献飞秒脉冲激光在氦气中自行聚焦的临界功率J. Bernhardta, , P.T. Simarda, W. Liua, b, H.L. Xua, F. Thébergea, c, A. Azarma, J.F. Daiglea and S.L. ChinaaCentre d’Optique, Photonique et Laser (COPL) and Département de physique, degénie physique et d’optique, Université Laval, Québec, QC, Canada G1V 0A6 bInstitute of Modern Optics, Nankai University, Tianjin 300071, PR China cDefence Research and Development Canada – Valcartier, 2459 Pie-XI Blvd North, Québec, QC, Canada G3J 1X5于2007年11月30日发表，2007年12月2日投稿， 2007年12月26日在线刊登。

摘要用移动焦点的方法测量飞秒脉冲激光在氦气中的临界功率。

试验值是(1 atm) 268千兆瓦。

使用这个试值，非线性折射率推断是 3.6 × 10-21 cm2/W。

另外，区域电子密度或能量和压力也用于决定氦气的临界功率，取决于丝状形成过程的夹紧程度。

试值与移动焦点的方法的试值相同。

文章概述1、介绍2、实验3、结果和讨论4、结论致谢参考文献1、介绍最近，飞秒脉冲激光在空气中生产少周期豆类丝状形成有重要进展。

（见文[1], [2], [3], [4] 和 [5]。

）Couairon et al.打算用飞秒脉冲激光在压力梯度惰性气体丝状形成过程去产生压缩脉冲到下一个光学脉冲循环。

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Laser display design and productionDisplay technology is the use of electronic technology to provide flexible transform visual information technology.Laser display technology, known as the fourth generation" revolutionary" display technology of laser dis play technology, known as the fourth generation" revolutionary" display technology. Laser display is widely used in TV, projector, public information screen, digital cinema, home theater, pilot training, big screen command display system, water curtain imaging performances and other fields, in the successful realization of miniaturization, but also can be applied in mobile phone projection, individualized helmet display system.ProspectReportedly, the display industry is an important part of information industry. Laser display with high color saturation and three color laser as the display light source, a color gamut range, long service life, environmental protection, energy-saving advantages, so that the display system comprehensive performance substantially span, is considered to be" a revolution in the field of display".Laser display colors, color performance ability is flat TV 2 ~ 3 times; the service life is flat TV light source more than 10 times; the production process is environmentally friendly, no waste water, waste gas, waste discharge. In addition, the laser source is the core device composed of semiconductor material, each 18 months performance can be doubled and the cost is reduced by half, its cost reduction potential is tremendous." These advantages make the laser display to the rapid speed of development.ProspectReportedly, the display industry is an important part of information industry. Laser display with high color saturation and three color laser as the display light source, a color gamut range, long service life, environmental protection, energy-saving advantages, so that the display system comprehensive performance substantially span, is considered to be" a revolution in the field of display".Laser display colors, color performance ability is flat TV 2 ~ 3 times; the service life is flat TV light source more than 10 times; the production process is environmentally friendly, no waste water, waste gas, waste discharge. In addition, the laser source is the core device composed of semiconductor material, each 18 months performance can be doubled and the cost is reduced by half, its cost reduction potential is tremendous." These advantages make the laser display to the rapid speed of development.Current situation analysisThe domestic status quoChinese laser display technology level completely in sync with the world. In China the concept first laser display, laser display technology leader, academician of Chinese Academy of Engineering Xu Zuyan under the leadership of academician, laser display technology research projects after 3 National 863 project, and contained more than 10, in 2003 to obtain major breakthrough, has launched many generation of laser TV principle prototype. In 2006 the group completed the research phase of the mission objectives, 2007 laser display technology begins to enter industrialization stage.Foreign statusAs the" next generation" display technology competition the focal point, SONY, Panasonic, Hitachi, Toshiba, Mitsubishi, EPSON, Samsung and other well-known international showed giant, have increased in the laser display field development. Since 2005 there have been many companies introduce laser television concept prototype. According to the United States of America" laser focus world" professional mediaoptimistic forecasts, 2010 before and after laser display technology in the world will form a $57000000000 / year in industrial scale.In recent years, the International German, Japan and the United States, South Korea and other countries have invested enormous human and material resources for the full color laser display technology research. Japanese industry calls it" the human visual revolution in history", and to the power of the state, a well-known multinational companies to participate in joint development. In 2005, the Japanese Sony company in Aichi Expo launched a large-scale laser theater, show its technology development achievement; 2006 March, Japan Seiko Epson Corporation announced and the United States Novalux strategic cooperation, common development of laser display technology; 2006 February, Japan's Mitsubishi Electric announced the launch of laser TV prototype, and initially set up the industrialization program, to seek in the the future high technology competition to occupy the strategic commanding elevation. Laser show beyond all dispute to become a monochrome display, color display, digital display after the next generation display technology.Different display devices based on different physical principles. Any electronic display method is to change the optical properties of certain. Active display device is the device of self-luminous display device; passive by external light irradiation and the realization of display. There are a number of display method is the use of light refraction, diffraction and polarization to achieve.Display device:Display device by a display device and relevant circuits, used by the display device can be divided into different, electron beam display device, flat panel display device and projection type display device. The display processor is constituted of a display device is an important component, its function is to buffer, timing, control and coordinate transformation, data insertion and deletion, image changes, rotation, shift and various other data control. The display processor includes a refresh memory, its capacity to accommodate one or more digital data, to fit the vision requirements. In a display device such as a keyboard input device, a graphics tablet,,, trackball and lever, is man machine combination method, used to strengthen the function of display device.Laser is a kind of energy is highly concentrated, highly monochromatic coherent light source, with several different color, in a display of attention. In the military and public place of entertainment, use of the holographic principle can form stereoscopic image holographic display. However, the practical application of laser display by the light intensity and efficiency of a certain limit.Display software:In a computer controlled display device, display software is an important component in a computer system, is based on the software compiled. Interactive display device capable of interacting by the graphic software. Interactive graphic display software generally consists of basic graphics software, special graphics software and application software is composed of three parts. In a display system in certain applications, requires the application of three-dimensional rotation technique. 3D rotation, zoom and cross-sectional profile technique in medical, construction design and mechanical design display applications is very useful, is a complicated problem to display software.Display system:Depending on the application, by one or more, one or a plurality of display device is composed of the availability of visual information electronic system. It received from various electronic equipment or system signal. Display system generally need to beequipped with the appropriate input device and the necessary recording equipment, in order to realize man machine contact and for later investigation by.Electron beam tube display device in display technique is still occupied the main position, but all board or wall display device (i.e., a matrix display ) superiority, will get developing quickly. Projection display technology has been flat screen display replaces the trend. Display software in intelligent display device is very important. Graphic language standardization, the wide application of computer display has a huge impact, thus great attention. Computer display technology development will promote the development of display software.A new image reconstruction technology makes full use of the advantages of the laser itself. In the light of the dissemination method, laser light source with the traditional incandescent lamp has a fundamentally different: ordinary incandescent light in all directions and laser emission, will all the light gathering in a parallel beam of light. In addition, the laser projector than traditional projector can express more color range, to provide more clear images. High definition allows the laser projector can be used for traditional projector is not applicable in some areas. The current widely used with halide lamp traditional projector cannot arbitrarily to around the room projection, projection lens compensation because only a very small distortion, so in principle should show near the axis of the projector, generally located in the center of the room. Laser irradiation in a vertical or horizontal angle of the screen, the effect is the same, no distortion. Even odd projection geometry, such as an arch screen, or even a circular screen, laser projection in any place will not produce ambiguous phenomenon. Laser projector such characteristics for annular projection to create a better future. In practical application, laser technology and many other advantages: compact projection head and laser unit can be separated; the laser unit can be hidden in the room, only the small projection head is exposed outside; the inclined projection distortion can be very simple correction etc..Laser display is red, green, blue ( RGB ) of three primary colors of laser light source for the display technology, can the true reproduction of the objective world rich, bright colors, and provide more powerful expressive force. Compared with natural light color gamut, a conventional display device can only reproduce the human eye can see colors in 30% and currently under development in the laser display can cover 90%, the huge potential for us to laser display technology of the future is full of expectations, so the laser display is known as" the human visual revolution in history".Supporting conditionsLaser technology laser display industry 's main support conditions. This requires that we strengthen the development of laser technology, especially in the laser technical breakthrough, because the laser has a direct influence on the effects of laser display. At present our country is in this respect is relatively deficient, is still mainly to imports.Laser technology is another major supporting conditions is investment. Laser display industry is a research and development process of long compared to the industry, long-term investment in research and development is a lot of enterprises can afford, so need government invested scientific research funds for research and development. Only in this way can we ensure the laser technology of rapid development.Industry chainLaser display industry chain is very long, the semiconductor chip from the R & D and production of semiconductor laser research and development production to R & D and production of laser TV affect microelectronics, optical and electrical appliances, white black appliances fields. The downstream industries have terminal productsmanufacturing industry ( for example displays, projectors and other equipment production ), the upstream industry semiconductor device production. Increase strength to drive laser display industry development will be able to drive a lot of high-tech industry development.Restricting factorsChina is now the development of laser display industry has encountered some difficulties, as follows:In 1, the semiconductor laser weak industrial base is the leading cause of our laser display with high power semiconductor laser rely mainly on imported from abroad is main reason, especially in high power semiconductor lasers extension and chip technology greatly limits the domestic development of laser display technology.In 2, the laser display technology has just completed the research phase of the mission, is entering the stage of industrialization. Due to the lack of industry chain, industry key link mechanism is not perfect and other reasons, all of the technology and market lack enough understanding, so the laser display is in the technology without the condition of product.In 3, terminal enterprises difficult to organize the complete laser display technology chain and industry chainIn 4, upstream development force is dispersive, capital throws inadequacy,low-level repeat construction serious. First of all, as the downstream terminal products manufacture of China's color TV enterprises because of historical reasons, it is difficult to organize the complete laser display technology chain and industry chain. Secondly, as the upper reaches of the enterprise, as the development of scattered strength, insufficient R & D investment, resulting in uneven level, low-level repeat construction serious.Policies and measuresBy means of laser display in the high-end market, special ( including all kinds of Engineering ) demonstration application, create market demand, expanding the size of the market, and promote the development of all kinds of social resources in the downstream areas, investment, form a complete mature laser display industry chain.Union, downstream enterprises in the fields of laser display industry alliance, organization, and make full use of our country in the color gamut, decoherence shimming technology and index of advantage, develop the relevant standards, for China's laser display industry group to provide protection.Improve the industrial chain, industrial union organization at the same time, government support is also essential, it will reduce the production cost, improve the technical chain has played a positive role.Increase innovation strength, encourage technical innovation in the field of innovation behavior, reward, through various measures to stimulate the laser technology innovation.Through the combination of production and research advance of laser display industrial key technology researchers will work extends to the industrialization of technology and technology research and development, for the production of manufacturers including system design, integration and key components of production process, relatively complete industrial technology solutions, and through the early entry in the local market, technology and product demonstration, creating a market demand and to the relevant manufacturers to promote technology solutions.Seize the international display industrial upgrading opportunities, as soon as possible to achieve laser show ( TV ) industrialization, as soon as possible to achieve the display industry upgrading.By the relevant government departments, organization support, relying on the advantage of units, as soon as the breakthrough of low cost integrated all-solid-state RGB light source, the standardization of shimming a decoherence device large-scale production technology and techniques, to construct the complete mature laser show( TV ) technology chain.By means of a laser show ( TV ) in the high-end and special market ( including all kinds of Engineering ) demonstration application, expand the size of the market, and promote the development of all kinds of social resources in the downstream areas, investment, construction of complete laser show ( television ) industry chain.Laser display technology research and development:Laser display technology research and development can be divided into 4 stages: the concept stage, development stage, early stage and industrialization scale industrialization stage. Laser display concept in the last century 60's, countries around the world scientists try to laser technology will be applied to the display light source research. Chinese Academy of engineering, Xu Zuyan first in the domestic the laser display concept, and made a preliminary study. But then the laser development level, project progress is slow. The last century 90's, along with the solid-state laser materials developed, greatly promoted the laser display technology research, 2003 laser display technology research to obtain historic breakthrough, through RGB three color of visible light laser successfully mixed into white light, and introduced a series of Engineering prototype. From 2005 to 2010, is a laser display industrialization stage, where China and the world famous enterprises have introduced the laser projector, laser TV principle prototype, laser display industry has entered the industrialization stage, at this stage, countries are stepping up the construction technical integrity of the industry chain, accelerate industrial demonstration and patent and technical standard. Around 2010 the laser display industry will enter a period of rapid growth, the laser display market of up to $57000000000 a year in industry scale.China's laser display industry development present situation:Laser show in 2005 was included in the national medium - and long-term development planning, and become a key technology, laser display technology in 2006 by the Ministry of information industry as "the overall technology advanced world, the world's leading key index". In 2003, RGB three color laser R & D initially completed, the introduction of laser display prototype, to launch in 2005 60 inch, 80 inch, 140 inch prototype laser TV, 2006 by the Ministry of information industry identification, launched 200 inch front projection prototype, completed in 2007 40 square meters projection screen laser digital film projector prototype.In order to promote the rapid development of laser display industry, Chinese Academy of Sciences in 2006 jointly founded the folk capital" in Beijing as a branch of photoelectric technology limited company", is committed to the implementation of the industrialization of laser display technology. The company by a number of academicians, industry experts as technical and strategic advisor, for laser display technology industrialization development of all-round support. In the full color laser display technical field, our country has a complete independent intellectual property rights of chain, have in the field to realize industrialization breakthrough foundation.The full color laser display technology industrialization project carry out smoothly, can give full play to our country in the electronic, electrical manufacturing industryadvantage, but also in the creative industry, information industry play a leading role in the country, driven the rapid development of relevant industry. Laser display industry upstream industries include: new materials, precision machining, laser, video standard; downstream industries include: multimedia public display, large screen control system, digital cinema, home theater, mobile video. Development of the full color laser display industry will achieve a new high-tech industry cluster.At the application level, laser display technology will become the future high-end display mainstream, applied to public information screen, laser TV, mobile phone, digital cinema projection display, projection display, portable screen directing a laser DLP projection principleAnd individualized helmet display system and other fields, in the large screen show a more realistic, more colorful dynamic image, generating beat all shock. Future display may be laser technology to replace the ordinary film projectors, color space can only cover the human eye can recognition color space 33%, and laser film projector can beup to 70%, or even 90%. Laser projection luminous efficiency is high, the traditional projection bulb is a halogen bulb, only the 2-3% energy is converted into heat energy, the other, also is afraid of vibration. The laser projection power consumption is relatively small, can not generate heat. Its life can reach 100000 hours, after high temperature aging test projected life up to millions of hours, so it is a long instructed the high reliability of the products.The full color laser display the product's advantages are: color space, color rich, high color saturation, color expressive force is the traditional TV more than 2 times; secondly, the light source and long service life, maintenance costs overall low use cost, laser light source completely break the traditional light source photoelectric conversion mode, life up to 10 years, is the traditional light source life 10 times to 20 times; third, production equipment, small investment scale, the laser display production equipment investment, can range from tens of millions of dollars to hundreds of billions of dollars invested; fourth, environmental protection and energy saving, power consumption is only 1 / 3 of the traditional TV, very much in line with the national policy of energy saving and emission reduction, and laser light source during the production process the use of a threat to the environment of the metal material, and is an environment friendly light source; fifth, cost reduction potential, with the enlargement of the industry scope and the adoption of new technology, the laser display system design to produce revolutionary change, in improving the display quality and greatly reduce the cost.Laser display, is the second display black and white, color display, digital display after a new generation of technology, known as" the human visual history of revolution", has the color gamut range, long service life, environmental protection and other features. Miniature solid state laser was created, the computer will no longer need the LCD screen, only whenever and wherever possible projection; because of the laser, mobile phone screen can be enlarged several times.At the application level, laser display technology will become the future high-end display mainstream, applied to public information screen, laser TV, mobile phone, digital cinema projection display, portable projection display, large screen command and individualized helmet display system and other fields, in the large screen show a more realistic, more colorful dynamic image, generating beat all the shock.Future display may be laser technology to replace the ordinary film projectors, color space can only cover the human eye can recognition color space 33%, and laser film projector can be up to 70%, or even 90%. Laser projection luminous efficiency is high, the traditional projection bulb is a halogen bulb, only the 2-3% energy isconverted into heat energy, the other, also is afraid of vibration. The laser projection power consumption is relatively small, can not generate heat. Its life can reach 100000 hours, after high temperature aging test projected life up to millions of hours, so it is a long instructed the high reliability of the products.Laser display future applications included in the mobile phone display, portable projector and a backlight television and cinema, can be widely used in the market. And the Chinese Academy of Sciences and recently also in consideration of how the laser source is applied to the liquid crystal television lighting, the new type of light source and the current mainstream TV technology combined with.激光显示器的设计与制作显示技术是利用电子技术提供变换灵活的视觉信息的技术。