触摸屏知识（Touch screen knowledge）.doc

触摸屏知识（Touch screen knowledge） A touch screen, type and principle The basic principle of touch screen, touch touch screen display installed in front of the fingers or other objects, the touch position (to coordinate form) by the touch screen controller detection, and through the interface (such as RS-232 serial port) to CPU, so as to determine the input information. The touch screen system includes a touch screen controller (card) two parts and touch detection device. The touch screen controller (card) the main function is to receive information from the touch touch detection device, and convert it to contacts, and then sent to CPU, at the same time it can receive the CPU command and execute: the touch detection device is usually installed in the front of the display, the main function is to detect the users touch the location, and transmit to the touch screen control card. 1. resistive touch screen The resistive touch screen body part of the screen is a multilayer film and a display surface, a layer of glass or organic glass is used as the base, the surface coated with a layer of transparent conductive layer, which is covered with a layer of outer surface hardening, smooth scratch resistant plastic layer, its inner surface is also coated there is a layer of transparent conductive layer, there are many tiny between two layers of conductive layer (less than 1/1000 inches) of the transparent isolation points separated them insulation. When a finger touches the screen, the usual two mutually insulated conductive layer on the touch position have a contact, because the direction of one side of the conductive layer on the Y axis of the 5V uniform field voltage, the voltage detection layer changes from zero to zero, which is connected to the state controller to detect, A / the D conversion, and then the voltage value can be compared with the 5V touch Y axis point, similarly obtained X axis, which is all the basic principle of resistive touch screen in common. Key resistance