IR Touch functions due to vertically and horizontally embedded arrays of transmitter/receiver pairs consisting of an IR LED and light sensors along the edges of the touching devices. Infrared touch uses light emitting diodes and sensors. Any physical touching within the working area can be detected as an interruption of signals received by light sensors. The position of the interrupted pairs is converted to the exact coordinate where the touching occurs. Raysees IR LED light source has a controllable light ray path to effectively enhance efficiency. The photodiode on the receiving end features a large field of view (FOV) and high uniformity. GRay™ IR LED light source is widely used in various touch screen devices like an interactive whiteboard or IR touch control systems.