Patent ID: 6573961
Filing Date: 2003-06-03
Classification: B82Y,C09K,E06B,F24S,G01D,G02B,G02F,Y02E

Abstract:
A reflective cholesteric liquid crystal color filter comprising:a first layer of reflective cholesteric liquid crystal color filters of one handedness havig at least a first light reflecting portion reflect a first bandwidth around a first center wavelength and a second light reflecting portion reflecting a second bandwidth around a second center wavelength and, a second layer of reflective cholesteric liquid crystal color filters of the same handedness as the first layer having at least a third light reflecting portion reflecting a third bandwidth around a third center wavelength, and a fourth light reflecting portion reflecting a fourth bandwidth around a forth center wavelength, the second layer of reflective cholesteric liquid crystal color filters adjacent the first layer of reflective cholesteric liquid crystal color filters such that adjacent first and second layer reflecting portions reflect different wavelengths of incident light of the same handedness and transmit the remaining wavelengths, and third and fourth layers of cholesteric liquid crystals, the third layer matching the first layer except with opposite handedness and the fourth layer matching the second layer except with opposite handedness such that any incident light with a selected color is transmitted through the color filters and incident light for all other colors is reflected, wherein the first reflecting portion overlaps the third and fourth reflecting portions and the fourth reflecting portion overlaps the first and second reflective portions, and further wherein the second reflecting portion and third reflecting portion do not overlap each other and reflect the same wavelengths, such that three bands of wavelengths are transmitted through the two layers.