Patent ID: 6812983
Filing Date: 2004-11-02
Classification: G02B,G02F

Abstract:
A retardation plate comprisinga first layer which comprises a material including a positive intrinsic double refraction value and a second layer which comprises a material including a negative intrinsic double refraction value, with the materials of the first and second layers when laminated and stretched resulting in retardation for wavelengths of electromagnetic radiation for the plate; and wherein for wavelengths of 450 nm, 550 nm, and 650 nm, the plate retardation value for wavelengths of 450 nm is less than the plate retardation value for wavelengths of 550 nm, and the plate retardation value for wavelengths of 550 nm, is less than the plate retardation value for wavelengths of 650 nm; and wherein said first layer and said second layer each include lag axes, and are laminated to one another and stretched such that lag axes of said first layer and said second layer are substantially orthogonally crossed.