Patent · US Expired

Half tone liquid crystal display circuit with an A.C. voltage divider for drivers

US5250937A · kind A · utility

67Cited by
7References
30Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 8, 1991
Grant dateOct 5, 1993
Priority date
Expiry dateMar 8, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G2330/08
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A half tone liquid crystal display circuit is disclosed including a voltage divider using as a reference voltage a voltage which is approximately determined on the basis of a point of intersection of the extensions of straight lines along the gradients of brightness-voltage characteristics corresponding to at least two observation angles vertically different with respect to a liquid crystal display panel having a TFT active matrix structure to generate driving voltages for the half tone displays associated with a voltage varied to correspond to the observation angles; and a correcting voltage waveform generator for generating a dynamic observation angle correcting voltage varied in association with a vertical scanning operation corresponding to the difference in the vertical observation angles of a liquid crystal display frame. The half tone driving voltages generated by the voltage divider from the dynamic observation angle correcting voltage are subjected to level modulations.

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