Design Of Optical Touch Screen Control System Based On FPGA

Touch screen is a new way of human-computer interaction. As continuousdevelopment of technology and continuous improvement of products performance, itwill bring extraordinary experience to people in more fields. As a latest solution, thetechnology of optical touch screen is different from the existing resistors, capacitors,surface acoustic wave and infrared touch technologies. Due to its significant advantagesin accuracy, response speed and large-size application, it will become increasinglypopular in the touch screen market. Especially the creative multi-touch technology isicing on the cake to the optical touch technology.This paper designed a control system of touch screen under the correspondingapplication scenarios and indicators, which included FPGA as the core module, CCDimage sensors and infrared light source as the optical scanning module. Based on thepresented algorithm, this article first conducted overall system design which defined thevarious hardware modules, and then conducted the detailed design for each module inthe hardware circuit and FPGA interface timing to complete high-speed image scanning.Finally, the CORDIC algorithm of the system core was discussed to calculating theexact coordinates of the touch-point.By the board-level hardware debug, the simulation and timing analysis for eachFPGA logic module, we verify the accuracy and feasibility of the system whichachieved the desired goal.