Research And Design Of Large Size And High Resolution IR-touch Screen Based On ATmega88

As the newest input device the IR touch screen has played a very important role and it is the most simple and convenient way of communication between human beings and the computers. It gives the multi-media a new look and turns to be the attractive new multimedia interactive devices. As more and more extensive applications, it is also more and more in-depth impact on people's lives.The IR touch screen will be the final trend of the touch screen technology for it can work steady in the harsh environment. However the traditional IR touch screen has a low resolution and the use of it are limited. As more and more big size monitors are used in industry, it is calling for a high resolution to meet the need. What's more the outdoor light's interference also limited the use of IR touch screen.The IR touch screen has developed quickly as the whole industry advanced. The resolution of the IR touch screen used in mainland can get about 1000×720, and some high-end products even higher. In the abroad the resolution even can be 4096×4096, but the ability of anti-light interference is not strong. In view of this situation, this paper presents an anti-glare touch-screen interference in high-resolution infrared design and development program.In this paper, an overview of a variety of touch-screen principles are given, and the performance are compared. Then an anti-glare touch-screen interference in high-resolution IR touch screen is presented. The output voltage change of the infrared receiver is accurately quantified by the AD converter circuit, which translated into a corresponding change in coordinates. The 74HC138 and the 74HC238 chips are used to flexibly control the entire circuit. This design greatly reduces the use of components and the costs, but the performance is much more stable. After the design is complete, experiments are carried out to verify and analysis. Through the aging test, outdoor verification test and such tests to prove that the design of the program had achieved its target.This design of infrared touch screen with built-in structure is installed on a large display, and the resolution can get about 2046×1024. A good anti-interference performance make it used normally outdoor or under the flash lamp. It has characteristics such as accurate drift-free positioning and in response to speed and so on. The PCB area is significantly saved because of the simple circuit structure, and the border width of the touch screen was reduced to 17mm. Various tests show that this type of infrared touch screen has achieved the design goals, with both high precision and stability.