The broadband cholesteric optical device, and the polarizer and the filter which use that, liquid crystal device, and polarization bimusupuritsuta

摘要

PROBLEM TO BE SOLVED: To provide a wide band cholesteric optical device capable of substantially reducing dependency upon the incident angle/outgoing angle to be an optical characteristic and capable of having the optical characteristic for the oblique incident angle by reducing or compensating off axis double refraction depending upon the wavelength of a wide band cholesteric layer. ;SOLUTION: A wide band cholesteric optical device such as a polarizer or a spectral filter is provided with a wide band cholesteric layer 1. The cholesteric pitch, e.g. of the layer 1 is a grated pitch type to be monotonously increased from a certain face 2 of the film 1 to another face 3. In order to improve an off axis characteristic, a compensator is formed as a positive double refraction film 8 having an optical axis substantially vertical to the film 1. A negative double refraction film 9 having an optical axis vertical to the film 1 is also formed.;COPYRIGHT: (C)1998,JPO