Patents Examined by Anita Pellman Grass
  • Patent number: 4946259
    Abstract: A color liquid crystal display comprises a liquid crystal interposed between two transparent electrodes. The electrode on at least one side of the liquid crystal comprises a plurality of pixel electrodes, each pixel electrode defining the area of one pixel of the display. Two or more pixels together form a picture element of the color display. One pixel (a chromatic pixel) of each picture element has a color filter covering the pixel. The other pixel (an achromatic pixel) of each picture element has a translucent (noncolored) filter covering the pixel. The translucent filter also covers a peripheral region of each color pixel. The peripheral region of each chromatic pixel (which is covered by both the color filter and the translucent filter) forms a light shield to increase the contrast of the display. A transparent (noncolored) filter is provided over each achromatic pixel to adjust the overall thickness of the liquid crystal, so as to minimize light leakage at the achromatic pixels.
    Type: Grant
    Filed: January 24, 1990
    Date of Patent: August 7, 1990
    Assignee: International Business Machines Corporation
    Inventors: Haruhiro Matino, Toshihiro Ueki, Yasuhisa Oana, Motoji Kajimura