Industry Patents

A lighting device (100, 200, 300, 400) is disclosed. The device comprises a plurality of light sources (111, 119, 120, 211, 219, 220) providing light in different wavelengths, a collimating means (104, 204) having a receiving end (103, 203, 407) and an output end (114, 214, 409), wherein said light sources are arranged at said receiving end. The collimating means comprises a set of wavelength selective filters (109, 110, 115, 116, 117, 118, 215, 217) arranged as sub-collimators (106, 107, 108, 206, 207, 208) to each of said plurality of light sources such that, for each light source, said sub-collimator collimates the light from its light source, and said wavelength selective filter of said each light source is translucent for light from adjacent light sources of different wavelength, and a second set of wavelength selective filters comprising compensation filters (222, 224, 226, 228, 230, 232) wherein each compensation filter is arranged symmetrically with respect to corresponding part of the wavelength selective filter of said first set around a general light direction of the corresponding light source.