Patent ID: 6618103
Filing Date: 2003-09-09
Classification: G02F

Abstract:
A liquid crystal display element comprising:a pair of substrates; and a liquid crystal layer held between the pair of substrates, said liquid crystal layer containing a cholesteric liquid crystal that is substantially free of a polymer, wherein the liquid crystal display element is capable of switching the cholesteric liquid crystal to a colored state and to a scattering state by application of a voltage to provide image display, and wherein an integral value in a visible wavelength range of a formula {expâˆ’[2(&lgr;âˆ’nP)2/&Dgr;n2P2]}R â€ƒthat is expressed as a function of wavelength &lgr; is in a range from about 40% to about 60% of an integral value in the visible wavelength range of a function f (&lgr;) that represents a spectral reflectance in the colored state, wherein n is an average refractive index of the cholesteric liquid crystal, P is a helical pitch of the cholesteric liquid crystal, R is a light reflectance in a selective reflection wavelength nP of the cholesteric liquid crystal in the colored state and &Dgr;n is a refractive index anisotropy of the cholesteric liquid crystal.