Patent · US Expired

Liquid crystal display systems

US4393380A · kind A · utility

82Cited by
3References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 28, 1980
Grant dateJul 12, 1983
Priority date
Expiry dateMay 28, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G2300/0876
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A matrix liquid crystal display circuit operates on a level of AC voltage equal to the voltage required for DC drive. The circuit includes a selecting transistor connected to the picture element and a capacitor for each picture element of the matrix. The capacitor in each row connects to a common electrode and the transistor gates in each row connect to a common electrode. The voltage level of the common capacitor electrode is shifted periodically relative to a reference voltage in order to invert the image signal polarity across the picture element and produce an AC drive. Inverted image signals of similar voltage level are alternately sampled.

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