| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarizing element having excellent optical characteristics and capable of enhancing contrast and securing satisfactory visibility when assembled in a liquid crystal display device and the like. SOLUTION: When refractive indices of a cholesteric liquid crystal layer 11, a quarter-wave retardation plate 12 and an adhesive layer 13 are defined as n<SB>1</SB>, n<SB>2</SB>and n<SB>3</SB>, respectively, n<SB>1</SB>, n<SB>2</SB>and n<SB>3</SB>satisfy a relation n<SB>1</SB>≤n<SB>3</SB>≤n<SB>2</SB>or n<SB>2</SB>≤n<SB>3</SB>≤n<SB>1</SB>. Both the values of the refractive indices n<SB>2</SB>and n<SB>3</SB>are the values of average refractive indices. The value of the refractive index n<SB>1</SB>is obtained from an equation n<SB>1</SB>=n<SB>4</SB>×sinθ/sin(θ×b) based onθ×b andθdetermined so that an equationλ=a×cos(θ×b) (wherein a and b are constants) is satisfied betweenθandλwhen an incident angleθof light in changed, in measurement for detecting wavelengthλof reflected light when light made incident in the cholesteric liquid crystal layer 11 with the incident angleθunder an atmosphere of a refractive index n<SB>4</SB>is selectively reflected by the cholesteric liquid crystal layer 11, and the refractive index n<SB>4</SB>. COPYRIGHT: (C)2004,JPO
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