光电传感器(中英文对照版)

Photoelectric sensor

Key word: photoelectric effect photoelectric element photoelectric sensor

classification sensor application characteristics .

Abstract: in the rapid development of science and technology in the modern society, mankind has into the rapidly changing information era, people in daily life, the production process, rely mainly on the detection of information technology by acquiring, screening and transmission, to achieve the brake control, automatic adjustment, at present our country has put detection techniques listed in one of the priority to the development of science and technology. Because of microelectronics technology, photoelectric semiconductor technology, optical fiber technology and grating technical development makes the application of the photoelectric sensor is growing. The sensor has simple structure, non-contact, high reliability, high precision, measurable parameters and quick response and more simple structure, form etc, and flexible in automatic detection technology, it has been widely applied in photoelectric effect as the theoretical basis, the device by photoelectric material composition. Text:

First, theoretical foundation - photoelectric effect

Photoelectric effect generally have the photoelectric effect, optical effect, light born volts effect.

The light shines in photoelectric material, according to the electronic absorption material surface energy, if absorbed energy large enough electronic electronic will overcome bound from material surface and enter the outside space, which changes photoelectron materials, this kind of phenomenon become the conductivity of the photoelectric effect

According to Einstein's photoelectron effect, photon is moving particles, each photon energy for hv (v for light frequency, h for Planck's constant, h = 6.63 * 10-34 J/HZ), thus different frequency of photons have different energy, light, the higher the

frequency, the photon energy is bigger. Assuming all the energy photons to photons, electronic energy will increase, increased energy part of the fetter, positive ions used to overcome another part of converted into electronic energy. According to the law of conservation of energy: Type, m for electronic quality, v for electronic escaping the velocity, A microelectronics the work done.

From the type that will make the optoelectronic cathode surface escape the necessary conditions are h > A. Due to the different materials have different escaping, so reactive to each kind of cathode materials, incident light has a certain frequency is restricted, when the frequency of incident light under this frequency limit, no matter how the light intensity, won't produce photoelectron launch, this frequency limit called "red limit". The corresponding wavelength for type, c for the speed of light, A reactive for escaping.

A -h m 212νν=