Patents Examined by M. Fathi-yari
  • Patent number: 5038139
    Abstract: In a half tone display driving circuit for a liquid crystal matrix panel, a pulse for half tone display is phase modulated so that pulse signals which are out of phase relative to each other are applied to adjacent columns of the liquid crystal matrix panel, or from the phase-modulated pulse a gray scale pulse (tone pulse) is prepared in which the frequency of occurrence of voltage edges is decreased. The dephased pulse signals or the gray scale pulse (tone pulse) is used to prevent a decrease in brightness of display when the liquid crystal matrix panel is driven for half tone display.
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: August 6, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiro Fujisawa, Hiroyuki Mano, Satoru Tsunekawa, Kiyoshige Kinugawa, Satoshi Konuma, Tatsuhiro Inuzuka