An optical position sensing system includes a bezel surrounding a display, a position sensor assembly, and a processor for calculating touch locations. Prismatic film may be applied to the bezel. Each optical position sensor assembly includes a body. A lens holder holds an illumination window on a first...http://www.google.de/patents/US20090213094?utm_source=gb-gplus-sharePatent US20090213094 - Optical Position Sensing System and Optical Position Sensor Assembly
