| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a brightness enhancing film being a laminate of a λ/4 wavelength plate and cholesteric liquid crystal which has no problems in coating-liquid repellent properties and contact properties and provides stable retardation at wavelengths in a wide range and has a high brightness enhancing effect. <P>SOLUTION: The brightness enhancing film is a laminate wherein a cholesteric liquid crystal layer is provided, directly or through another layer, on cellulose ester film which has a slow axis in a range from 10° to 80° with respect to a lengthwise direction of the film and has an in-plane retardation Ro of 120 to 150(nm) in measurement at a wavelength of 550 nm and satisfies formulas (i) 2.1≤X+Y≤2.8 and (ii) 0.5≤Y≤1.65 wherein: X represents a degree of substitution of an acetyl group; Y represents a degree of substitution of a propionyl group or a butyryl group; and X+Y represents a total degree of substitution of acyl groups. <P>COPYRIGHT: (C)2010,JPO&INPIT |
