Patent ID: 8434887
Filing Date: 2013-05-07
Classification: G02B,G02F,G03B,G09G,H04N

Abstract:
1. A backlight for illuminating a spatial light modulator of a display, the backlight comprising: a plurality of independently controllable light sources, each light source comprising a group of two or more light emitters having different emission spectra, and each light source comprising a light integrator with an entrance and an exit, said light integrator being arranged such that the group of light emitters of the light source emits light into an entrance of the light integrator and such that said light exits the light integrator at the exit of the light integrator in a mixed state; and a plurality of cavities, each located at the exit side of a respective one of the light integrators, each cavity comprising one or more reflective surfaces inclined toward around the exit of the respective light integrator in order to confine a spread of the light exiting the respective light integrator, wherein nearest neighboring light sources are spaced at a distance L, wherein first and second light respectively emitted by two nearest neighboring light sources when fully turned on and after being confined by the one or more reflective surfaces of the respective cavities, are angularly distributed so as to overlap between said two nearest neighboring light sources at intensities greater than 45% of their peak values, and wherein the angular intensity distribution of each light source, when fully turned on and after being confined by the one or more reflective surfaces of the respective cavities, is such that the intensity at a distance L from the light source is less than 1% of its maximum intensity.