| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide band optical retardation plate which is manufactured with a simple process and at a low cost and which further gives nearly uniform phase difference characteristics with respect to incident light over the entire visible ray region. SOLUTION: The optical retardation plate is made by imparting alignment to a film comprising a polymer blend containing at least a kind of polymer with positive intrinsic birefringence value and at least a kind of polymer with negative intrinsic birefringence value. Preferably the optical retardation plate utilizes a norbornene resin and a styrene type resin as the polymers with the positive and negative intrinsic birefringence values respectively.
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