Patent ID: 7593079

Claim:
An optical element, comprising: at least three laminated circular-polarization-type-reflection polarizers (a) whose wavelength bands for selective reflection of polarized light overlap one another; a layer (b 1 ) which is placed between at least a pair of the circular-polarization-type-reflection polarizers (a) and has a front retardation of substantially zero (in the normal direction) and a retardation of at least λ/8 with respect to incident light inclined by at least 30° relative to the normal direction; and a layer (b 2 ) which is placed between at least another pair of the circular-polarization-type-reflection polarizers (a) and has a front retardation of substantially zero (in the normal direction) and a retardation of at most λ/2 with respect to incident light inclined by 60° relative to the normal direction.