White light illumination system

摘要

An improved apparatus for illuminating a display (10), such as a lens (14) in a pushbutton switch or a control pannel, includes a source (18) of nonwhite light of a first color at an energy level which can be perceived by the human eye. The nonwhite light of a first color is reflected from a reflector (22) to obtain white light. In one embodiment of the invention, the nonwhite light source (18) was a solid state device (light emitting diode) which produced blue light at a high-energy level and green and red light at relatively low energy levels with the result that the green and red light could not be perceived by a human eye simultaneously with the blue light. The light from the solid state light source (18) was reflected from a reflector (22) having a gold (yellow) reflecting surface (26). The light reflected from the reflecting surface (26) interfered with light emitted directly form the solid state light source (18) with a chromatic shift of light energy. The resulting light from the reflector (22) was white light.