×

Method of and apparatus for controlling contrast of liquid crystal displays while receiving large dynamic range video

  • US 6,414,664 B1
  • Filed: 11/13/1997
  • Issued: 07/02/2002
  • Est. Priority Date: 11/13/1997
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for controlling contrast in a liquid crystal display (“

  • LCD”

    ) device in which a full gray scale comprising minimum light out to maximum light out is used with variable video signal input ranges, with each video signal input range comprising a fraction of a total range of zero to full amplitude to be displayed by the LCD device, the full gray scale having a finite number of shades of gray, the LCD device having a contrast control for input by a user, the LCD device communicating with a drive voltage generator that supplies drive voltages V to the LCD device corresponding to the video signal input and a user contrast control setting, the method comprising the steps of;

    providing a plurality of look-up tables, the plurality of look-up tables representing a plurality of contrast settings of the LCD device; and

    selecting a single look-up table from the plurality of look-up tables in response to the contrast control setting selected by the user from the plurality of contrast settings through the contrast control device to affect a transfer function of the LCD device, the single look-up table containing all shade of gray available on the gray scale with each contrast setting.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×