Design and implementation of a multiple-touch system based on infrared technology

The multiple-touch system becomes more and more popular in resent years. The single-touch technology based on infrared technology develops rapidly and has been used in large-size human interface devices in various fields. However, the infrared-based multiple-touch technology has not been developed as well as single-touch technology because of its structural problems and ghost points. In this paper, we introduce a multiple-touch system with high performance embedded processor and special structure in hardware level. To solve problems of ghost points in a two-dimensional bi-axial coordinate system, a multiple-axial scanning algorithm is realized in software level making use of the character of infrared LED lights which have a typical viewing angle. As result of the unique hardware structure and the novel algorithm, we can recognize the multiple points successfully in the infrared based system.