| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a retardation plate for a wide band manufactured through a simple process and gives uniform retardation property to incident rays of the entire visible light range. <P>SOLUTION: Disclosed is a retardation plate containing a material whose intrinsic birefringence value is positive and a material whose intrinsic birefringence value is negative The material whose intrinsic birefringence value is negative is polystyrene or polystyrene-based polymer, and the polystyrene-based polymer is the copolymer of a styrene and/or styrene derivative with at least one type selected from among acryl nitrile, maleic acid anhydride, methyl methacrylate, and butadiene, When retardation values in wavelength 450nm, 550nm, and 650nm are respectively set to Re(450), Re(550), and Re(650), Re(450)<Re(550)<Re(650) is satisfied. The retardation plate is manufactured by melt extrusion. <P>COPYRIGHT: (C)2013,JPO&INPIT |
