A multi-function key system for use with an electronic device can include at least one key (230) and an optical film (255) optically coupled to the key. The optical film (255) can include a first optical filter (260) corresponding to a first color of light and a second optical filter (265) corresponding...http://www.google.ca/patents/US7523862?utm_source=gb-gplus-sharePatent US7523862 - Multi-function keypad using colored light sources and optical films
