Patent · US Expired

Gray level addressing for LCDs

US5861869A · kind A · utility

24Cited by
35References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 19, 1995
Grant dateJan 19, 1999
Priority date
Expiry dateMay 19, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G3/2022
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Method and apparatus for providing gray level addressing for passive liquid crystal display (LCD) panels having overlapping row and column electrodes defining pixels are disclosed. Depending upon whether the rows are being addressed by "standard" or "Swift" addressing, the signals for applying to the column electrodes are determined by different calculations, in all of which modes the amplitudes of the column signals are related to the gray level desired to be displayed by the individual pixels. For a split interval system, column signals of appropriate amplitude and polarity are applied during different subintervals of a characteristic time interval of the display panel depending upon the method of addressing the rows. In the full interval mode, the column signals applied over a full time interval are based on the desired gray level of all the pixels in the column, adjusted to provide the proper rms voltage across all the pixels so that they display the desired gray levels. The adjustment can be spread across multiple addressing intervals and can be added into the column signal when rows are selected or can be applied to the column electrode when no row is selected.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.