ACHIEVING COLOR BALANCE IN IMAGE PROJECTION SYSTEMS BY INJECTING COMPENSATING LIGHT

摘要

An image projection system improves the brightness and/or color balance of a projected image. The system includes an auxiliary light source from which compensating light co-propagates with polychromatic light emitted by a primary light source along a primary light path. The compensating light has an emission energy content that minimizes an emission energy imbalance introduced by the primary light source. In a first preferred embodiment, the auxiliary light source is affixed at a location near the entrance end of a light tunnel such that the compensating light coincides with the primary light path before first reflection occurs. In a second preferred embodiment, the auxiliary light source is coupled to a light reflector adjacent to the primary light source and thereby allows the compensating light to propagate through the image projection system with the same efficiency as that of the light generated by the primary light source.