Patents Examined by Hing Dang
  • Patent number: 5875014
    Abstract: An optically anisotropic film comprising a mixture of a polymer, a dye having an absorption peak not in a visible region but in an ultraviolet region, and occasionally a liquid crystal polymer, wherein the retardation of the optically anisotropic film is between 50 nm and 3000 nm, and the dye has an aspect ratio of 1.5 or more, or the dye shows a dichroism. The optically anisotropic film has a high wavelength dispersion of the retardation, and a liquid crystal display apparatus achieves an excellent black-and-white display by using the optically anisotropic film.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: February 23, 1999
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Masato Kuwabara, Toshihiro Ohnishi