4 Computer Peripherals

Perhaps the most natural tools are the light pen and the graphics tablet or digitizer. 光笔、绘图板或数字化仪应该是最常用的工具了。 数字化仪 绘图板；图形输入板 （2）Direct Input 直接输入 绝大多数 In an information system, the greatest majority of delays, errors, and problems occur during the input phase. 输入阶段 在信息系统中，延时、错误及出现问题大部分都发 生在输入阶段。 MIS
Unit 4
Computer Peripherals
Computer-System Input/Output
puter-System Input In order to use the information and applications of a computer system, you need some ways to input commands and text to the system. text (Commands are instructions that direct a device n. 击键；按键 vt. 用键盘输入； to perform a certain job. They can be words, keystrokes, or choices from a list.) list 为了使用计算机系统中的信息和应用程序， 人们 （命令就 需要某种向系统输入命令和文本的方法。 可以表现为 是指挥设备完成某个任务的指令， 文字、击键、或列表中的选项）。
平面艺术 绘图 Technical applications such as Technical applications such as graphic arts, mapping, and engineering often require specialized input methods. 像平面艺术、绘图和工程这样的技术应用通常 需要专门的输入方法。
运动探测器 Home computer users may link their systems to 温度计 thermometers, light detectors, and 阻止破坏 motion detectors to help control energy use and deter vandalism. 家庭电脑用户可以将他们的计算机系统与温度探 测器、光探测器及运动探测器连接起来，以控制 能源的使用、阻止非法入侵。 Input from these detectors is called sensor input. Sensor input is used widely with microcomputers in factories and in scientific and medical laboratories, too. 医学实验室 传感器输入也被广泛应用于工厂、科研机构 及医学实验室的计算机中。
光探测器
2. Computer-System Output 计算机系统的输出 运载工具 Output devices are the delivery vehicles of a computer system——that is, output hardware either delivers information to users in humanreadable form or stores the information for future use. 输出设备是计算机系统的传送工具，即，输出硬件 输出设备是计算机系统的传送工具， 将信息以人类可读的形式传送给用户，或者将信息 存储起来以备后用。
解决这个问题
To attack the problem, a number of methods To attack the problem,研究；开发；发展 methods a number of have been developed to increase speed, 共同地；全体地 accuracy, and reliability of input. Collectively, Collectively, 被称为 these techniques have been referred to as source data automation. Scanning, voice input, 传感器 and sensor input are three types of direct input. 为了解决这个问题，研究了许多提高输入速度、 准确度和可靠性的方法。 这些技术都被称为源数 据自动化。扫描、声音输入，以及传感器输入是 直接输入的三种类型。
语音识别
Speech-recognition, or voice-input, devices accept spoken words through a microphone and change the sounds into computer-readable signals. 语音识别（或声音输入）设备通过麦克风接收说话 的声音，并将声音转化为计算机可识别的信号。
(1) Display Outputs 显示输出 The most common output device is the monitor, a cathode-ray tube (CRT) that is basically a television tube adapted to present text, data, or images generated by computers. 监视器是最常见的输出设备，阴极射线管基本类 似于电视显像管，用于显示计算机生成的文本、 数据和图像。 High-quality color monitors receive three separate color signals (red, green, and blue) and thus are called RGB color monitors. 高性能彩色显示器接收三种独立的彩色信号 (红、绿、蓝)，所以也称为RGB彩色监视器。
光学的
Scanners, also called optical scanners, are devices that read printed material so that it can be put in computer-readable form without your having to retype, redraw, reprint, or rephotograph the material. 是一种可以读取印刷 扫描仪，又称为光学扫描仪， 材料的设备，并使印刷材料转变为计算机可读的形 而无须对这些材料重新输入、绘制、打印或拍 式， 摄。
Some screens themselves accept interactive input: The touch screen looks like a normal computer screen, but it can detect the point at which you touch. 接触屏的外观 有些屏幕本身可接收交互式输入： 和普通电脑屏幕很像，但它可以检测到你触摸的 那个点。
体积大的 The flat-panel displays used on portable computers are less bulky and require less power than CRT monitors. 便携式电脑所使用的平板显示器，比CRT显示器更 轻便和省电。
平面显示器 A common electronic imaging technique used in flat-panel displays is liquid-crystal display (LCD). 平面显示器使用的一种常见的电子成像技术就是 液晶显示（LCD）。 气体等离子体显示器 Two other flat panel displays are the gas plasma 电流 display, whicause 发热，发光 gases to glow, and the electroluminescent display (ELD), which is similar to gas plasma but has layers of phosphor rather than gas. 另外两种平面显示器分别是气体等离子显示器和 场致发光显示器ELD。
The two common forms of human-readable output are displays (video output) and printed documents. Computers are also able to communicate in sounds that imitate the human voice. 模仿，仿效 人类可读的两种常见的输出方式分别是显示（视 频输出）和打印文档。计算机也可以模仿人的声 音来实现交流。
The clarity or sharpness of the display is termed resolution. The resolution of a monitor indicates the number of image points, or pixels (picture elements), on its screen. 监视器的清晰度被称为分辨率。监视器的分辨率 表明屏幕上图片点、或像素（图片元素）的数量。 平板
计算机系统的输出outputdevicesarethedeliveryvehiclesofacomputersystemthatisoutputhardwareeitherdeliversinformationtousersinhumaneitherdeliversinformationtousersinhuman运载工具计算机系统的输出outputdevicesarethedeliveryvehiclesofacomputersystemthatisoutputhardware输出设备是计算机系统的传送工具输出设备是计算机系统的传送工具即输出硬件将信息以人类可读的形式传送给用户或者将信息存储起来以备后用
难使用的；笨拙的
Keyboard entry may be too slow or awkward for some jobs, but the keyboard can be bypassed by using one of a number of other interactive 逃开；忽视 devices. 对于某些工作，也许使用键盘输入太慢或难于使 用，可以使用其他许多交互式设备代替键盘。 Most of today's microcomputers, for example, include a mouse or a trackball that lets you use 轨迹球 natural arm or hand motions to move the cursor (See Fig. 4-1). 例如，目前大部分微型计算机都配有鼠标或轨迹 球， 使人们可以使用手臂或手的自然运动来 移动光标。（如图4-1）
人机交互 （1）Interactive Input 俘获；夺得 交互式输入 The idea of interactive input is to capture information directly into computers and get responses from computers as the input occurs. This happens when you type on a keyboard and immediately see the results of your work on a screen. It is so called as "screen-dependent". 交互式输入是指进行输入操作时，捕获的信息 直接输入计算机，并得到计算机的响应。 例如， 当你在键盘上敲击时，可以立即在屏幕上看到 自己敲键的结果。所以这又称为“屏幕依赖”。