Patent ID: 7767948

Claim:
A system comprising: A) a light fixture for a visible illuminating type lighting application, to illuminate or to provide task or object illumination, in a region or area intended to be occupied by a person, the light fixture comprising: 1) an optical integrating cavity having at least one diffusely reflective interior surface and an optical passage; and 2) a plurality of light emitting diodes (LEDs) coupled to supply light to the optical integrating cavity at points on an interior surface of the optical integrating cavity not directly visible through the optical passage in one or more directions to cause substantial portions of light supplied by the LEDs to reflect from said at least one diffusely reflective surface of the optical integrating cavity one or more times to optically integrate the light from the LEDs before emission as the optically integrated light through the optical passage of the integrating cavity for the visible lighting application, wherein the LEDs provide sufficient light energy in the optically integrated light to facilitate said visible illuminating type lighting application, and the optical integrating cavity is configured to direct the optically integrated light emitted through the optical passage in a direction to facilitate said visible illuminating type lighting application; and B) a control circuit coupled to the LEDs for establishing output intensity of light of a first one of the LEDs and separately establishing output intensity of light of a second one of the LEDS, to set light contributions of the LEDs to the optically integrated light within the cavity and thus set a characteristic of the optically integrated light emitted through the optical passage of the optical integrating cavity.