User-interface illuminator

DETAILED DESCRIPTION According to an embodiment of the present invention, a more efficient single light source with a improved conversion of electrical power to optical power replaces the use of multiple LEDs to achieve a higher energy conversion and corresponding lower power consumption.
By using a collimated light beam and using total internal reflection to guide the beam and branches of the beam to viewing surfaces, the total electrical-optical power efficiency of the embodiment is dramatically higher than current solutions.
A manufacturer has fewer components to purchase, maintain quality on, and assemble.
Also weight, size, volume, number or required electrical connections, etc.
may be reduced.
The outcome is that inventories are smaller, and manufacturing defects are diminished also increasing reliability.
Also, fewer conductive traces are needed to carry electricity to remote parts of the user-interface, resulting in fewer opportunities for defects and failures during manufacturing or use caused by open circuits or short circuits.
An object and advantage of the invention is that the optical power emitted by a light source is propagated through a medium and reflected to illuminate a generally flat area to provide high visibility of silhouetted button markings and LCDs, among others.
An attendant advantage is that the generally flat area may have an irregular perimeter.
Another object and advantage of the invention is a light source may be located at greater distances from its target without appreciable light leaking to unintended areas.
Another object and advantage of the invention is that a single light source may be directed to multiple targets without losses typically associated with reflection.
Still another object and advantage of the invention is that light may be provided through a structure that is thin as compared to either its height or length.
In another embodiment of the invention light is guided to a main output surface, and also to a secondary surface not coplanar with the main output surface