US Patent 7333031 Illuminated keyboard

Method and apparatus for illuminating selected keys on a computer keyboard. The illumination color, intensity, duration and the blink rate for each key are under the control of the computer. Key select codes from the computer are mapped onto the keyboard matrix such that any computer key code can select any key on the keyboard. Multiple keys can be illuminated by time multiplexing the illumination drivers to the key matrix in a manner such that the intensity of any key does not vary regardless of the number of keys that are illuminated.