Patent ID: 7724450

Claim:
A process for producing distinguishable colored light in the presence of ambient light, the process comprising: energizing a light emitting diode (LED) first light source emitting light into a first optical cavity at least partially defined by a first reflector portion configured to reflect light emitted by the first light source out of the first optical cavity, the first light source emitting a non-white colored light within a first wavelength band; passing the light within the first wavelength band generated by the first light source through a first filter positioned in an optical path between the first light source and the first reflector portion, the first filter attenuating light outside the first wavelength band but allowing light emitted from the first light source to pass substantially unattenuated so as to be reflected out of the first optical cavity by the first reflector portion; and filtering, by the first filter, ambient light after the ambient light has entered the first optical cavity and reflected off the first reflector portion, such that ambient light outside said first wavelength band is attenuated by the first filter, whereby the ambient light outside said first wavelength band that has entered the first optical cavity is attenuated by the first filter prior to being reflected out of the first optical cavity by the first reflector portion, enabling the light emitted by the first light source within the first wavelength band to be more distinguishable in the presence of the ambient light.