| 摘要 |
PURPOSE:To improve S/N by providing a circular polarizer, the central wavelength of which is adjusted equal to the selective reflection wavelength of a cholesteric high-polymer liquid crystal as an optical recording layer, into an optical path for writing and reading and adjusting the rotating direction of circularly polarized transmission light as to coincide with the spiral rotting direction of the cholesteric. CONSTITUTION:The cholesteric high-polymer liquid crystal is used as the optical recording layer 5. The circular polarizer 2, the central wavelength of which is adjusted equal to the selective reflection wavelength of the cholesteric high- polymer liquid crystal, is installed into the optical path for writing and reading. The rotation direction of the circularly polarized transmission light is adjusted to coincide with the spiral rotation direction of the cholesteric. The writing is executed by impressing an electric field simultaneously with projection of semiconductor laser light to the recording layer to form a homeotropic orientation. The erasing is executed by projecting the semiconductor laser light to the recording layer to cool the same slowly and forming the same as the original planar orientation. The change of reflectivity is thereby increased and the S/N is improved. |
