| 摘要 |
PROBLEM TO BE SOLVED: To suppress surface reflection and to widen a visual field angle by using phase difference plates satisfying specific regulation in combination as a second phase difference plate to be used for a circularly polarizing plate and a first phase difference plate to be laminated on a liquid crystal cell. SOLUTION: The sum of the refractive index ratio N21 of the first phase difference plate 1 calculated by the calculation equation Nz1=(nx1-n1y)/(nx1-ny1) and the refractive index ratio Nz2 of the second phase difference plate 2 calculated by the calculation equation Nz2=(nx2-ny2)/(nx2-ny2) is set at >=0 to <2.0 and the difference between the retardation of the first phase difference plate 1 and the retardation of the second phase difference plate 2 is specified <=20 nm. In the equations, nx1 denotes the refractive index in the phase delay axial direction within the plane of the first phase difference plate 1; ny1 denotes the refractive index in the phase advance axial direction within the plane; nz1 denotes the refractive index in the thickness direction. Further, nx2 denotes the refractive index in the phase delay axial direction within the plane of the second phase difference plate 2; ny2 denotes the refractive index in the phase advance axial direction within the plane; nz2 denotes the refractive index in the thickness direction.
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