Led light source

Abstract

Proposed is a lighting moduleand an illumination devicecomprising such a module. The lighting module comprises an array of LEDsmounted on a substrateand an optical structureencompassing the LED array for approximating in operation the LED array as a single homogeneous light source. The optical structure comprises an optical elementarranged to provide a luminous intensity profile as a function of a deviation angle a which is substantially constant between −αand α, wherein αis a maximum deviation angle provided by the optical element and substantially zero at angles outside that range. This is especially advantageous for optimizing the trade off between creating a single homogenous light source and maintaining the entendue of the light source. An additional advantage of the optical elementis that, except for fresnel reflections on both surfaces, it has no backscattering like a diffuser has, which results in a very low optical loss.