Patent ID: 6926418

Claim:
A light guide for use in a hand-held electronic device having an electronic circuit, a plurality of keys to allow a user to input signals to the electronic device via the electronic circuit, and a light source capable of providing light to illuminate the device, said light guide comprising: an optically transparent sheet, disposed adjacent to the electronic circuit, the sheet having a substantially even thickness defined by a first boundary interface, and a second boundary interface, the second boundary interface facing the electronic circuit, the sheet having an edge joining the first boundary interface and the second boundary interface, wherein the sheet comprises a plurality of dome-shaped sections for use as a plurality of touch members defining the keys and wherein the sheet is adapted to receive at least a portion of the light provided by the light source through the edge so as to allow the received light to propagate in the sheet including the dome-shaped sections between the first and second boundary interfaces, and wherein the sheet has a plurality of light escapement surfaces disposed at the touch members to allow a portion of the light received through the edge to escape from the sheet for illuminating the keys.