显示屏

显示器是属于电脑的I/O设备，即输入输出设备。它可以分为CRT、LCD等多种。它是一种将一定的电子文件通过特定的传输设备显示到屏幕上再反射到人眼的显示工具。
1 CRT显示器：Cathode Ray Tube阴极射线显像管显示器
	1.1	组成：	由电子枪、偏转线圈、荫罩、粉屏、玻璃外壳组成；
	1.2	性能指标：	分辨率、刷新频率、行频、点距、电磁辐射；
	1.3	优势：	可视角度大，无坏点，响应时间极短，色彩还原度高，色彩均匀，是游戏玩家和图像制作人士的首选；
	1.4	劣势：	辐射和屏幕闪烁容易使人产生疲劳；

2 LCD显示器：通过控制是否透光来自动调整明暗度，画面稳定无闪烁，无辐射，其性能指标包括：
	1.1	点距	在大小固定的前提下，点距越小图像越清晰；
	1.2	真实分辨率	1024768,设为800600时，超出部分为黑屏，扩展显示则效果不好；
	1.3	色彩数量	比CRT少，目前主流是18位色，即2的18次方：262144色，现在的操作系统和显卡都支持32位色；
	1.4	响应时间	各像素对输入信号反应的速度，常说的25ms,16,12.8ms就是指响应时，响应时间越短，看动态画面时越不会有尾拖曳的感觉；
	1.5	可视角度
	1.6	亮度
	1.7	对比度

液晶显示屏

由水平和垂直排列的液晶显示单元和背部光源等部分组成的，每个液晶单元中都有一个薄膜场效应晶体管（TFE），用以控制液晶显示单元的透光率。

整个显示屏在水平和垂直驱动信号的上显示图像；

水平驱动和垂直驱动集成电路分别安装在液晶屏的边缘，通过水平和垂直的坐标引线实现对每个像素单元的控制；

大致由九层组成

玻璃基板

彩色滤光板

液晶

玻璃基板

偏光板

光扩散层

导光板

反射板

外壳（塑料）

彩色显示屏是由很多排列整齐的像素单元构成的，而每一个像素单元都由红、绿、蓝三个滤光镜组成；

笔记本电脑液晶显示屏是不发光的，因此在液晶显示屏的背部设有背光灯作为液晶显示屏的光源，并通过导光板变成平面光。背光形成的平面光通过液晶屏显现出单色图像，然后通过RBG三基色滤光膜构成的彩色显示屏形成彩色图像，

touchscreen monitor

How do touchscreen monitors know where your're touching?

Touchscreen monitors have three basic systems that are used to recognize a person's touch:

触摸式屏幕显示器采用3种基本方法来识别触摸：

resistive

电阻性

capacitive

电容性

surface acoustic wave

表面声波

The resistive system consists of a normal glass panel that is covered with a conductive layer and a resistive metallic layer.These two layers are held apart by spacers,and a scratch-resistant layer is placed on top of the whole setup.An electrical current runs through the two layers while the monitor is operational.When a user touches the screen,the two layers make contact in that exact spot.The change in the electrical field is noted and the coordinates of the point of contact are calculated by the computer.Once the coordinates are known,a special driver translates the touch into something that the operating system can understand,much as a computer mouse driver translates a mouse's movements into a click or a drag. 电阻性触摸式屏幕显示器使用一块普通的平板玻璃，上面一层导电性

金属层和一层电阻性金属层。这两层之间由间隔器分隔，而在整体表面又涂一层抗划痕材料。显示器我作时，电流分别在导电性金属层和电阻性金属层上流动。当用户触摸屏幕时，两层之间在那一点接触。电脑注意到电场的变化，并且计算出接触点的坐标。一旦知道坐标以后，专用的驱动程序就把触摸翻译成操作系统能够了解的信息，就像鼠标驱动程序把鼠标的动作翻译成点击或拖曳一样。

In the capacitive system,a layer that stores eletrical charge is placed on the glass panel of the monitor.When a user touches the monitor with a finger,some of the charge is transferred to the user,so the charge on the capacitive layer decreases.This decrease is measured in circuits located at each corner of the monitor.The computer calculates,from the relative differences in charge at each corner,exactly where the touch event took place and then relays that information to the touchscreen driver software.One advantage that the capacitive system has over the resistive system is that it transmits almost 90 percent of the light from the monitor,whereas the resistive system only trnasmits about 75 percent.This gives the capacitive system a much clearer picture than the resistive system.

在电容性触摸式屏幕显示器中，平板玻璃上覆盖一层能存放电荷的电容性物质。当用户用手指触摸显示器的时候，某些电荷转移到用户身上，因此在电容层上的电荷减少。这一减少被位于显示器各个角落上的测量电路监测到。电脑从电荷在各个角落的相对差别可以计算出发生触摸的确切位置，然后把信息转送给触摸式屏幕驱动程序。电容性系统优于电阻性系统的地方是它的透光性差不多是90%，而电阻性系统只有大约75%。因此电容性系统的图像比电阻性系统清楚得多；

On the monitor of a surface acoustic wave system,two transducers(one receiving and one sending) are placed along the X and Y axes of the monitor's glass plate.Also placed on the glass are reflectors-they reflect an electrical signal sent from one transducer to the other.The receiving transducer is able to tell if the wave has been disturbed by a touch event at any instant,and can locate it accordingly.The wave setup has no metallic layers on the screen,allowing for 100-percent light throughput and perfect image clarity.This makes the surface acoustic wave system best for displaying detailed graphics(both other systems have significant degradation in clarity).

在表面声波系统的显示器中，沿显示器平板玻璃的X轴和Y轴各旋转一个声波变送器（发射和接收）。在玻璃上还旋转了若干个反射器。它们把从一个变送器发送的电信号反射到另一个变送器。变送器的接收装置能测出声波在任一瞬时被触摸干扰，并且能相应地打出它的位置。表面声波系统的显示器中没有金属层，百分百的可以通过，显示清晰完善的图像。因此如果要显示详细的图像最好使用表面声波系统。

Another area in which the systems differ is in which stimuli will register as a touch event.A resistive system registers a touch as long as the two layers make contacct,which means that it doesn't matter if you touch it with your finger or a rubber ball.A capacitive system,on the other hand,must have a conductive input,usually your finger,in order to register a touch.The surface acoustic wave system works much like the resistive system,allowing a touch with almost any object except hard and small objects like a pen tip.

as far as price,the resistive system is the cheapest;its clarity is the lowest of the three,and its layers can be damaged by sharp objects.The surface acoustic wave setup is usually the most expensive.