Patent ID: 6769792
Filing Date: 2004-08-03
Classification: F21S,F21V,F21W,G02F,H04N

Abstract:
A color cross-fading system for a luminaire which comprises first and second filter elements each comprising a substrate having thereon a plurality of layers of materials having different refractive indices, thickness of such layers varying continuously along a gradient axis of each filter element,said first filter element having a predominantly long wave pass characteristic such that at each point along said gradient axis visible light waves with wavelengths longer than a first cut-off wavelength are passed, said first cut-off wavelength proportional to said thickness of layers, which varies continuously along said gradient axis, said second filter element having a predominantly short wave pass characteristic such that at each point along said gradient axis visible light waves with wavelengths shorter than a second cut-off wavelength are passed, said second cut-off wavelength proportional to said thickness of layers, which varies continuously along said gradient axis, and means for mounting said first and second filter elements for movement independently of one another relative to an optical axis, whereby any point on the gradient axis of each filter element can be independently brought into alignment with the optical axis.