Patent · US Expired

Method of testing liquid crystal display substrates

US5465052A · kind A · utility

27Cited by
36References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 10, 1991
Grant dateNov 7, 1995
Priority date
Expiry dateSep 10, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/1309
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Construction defects in liquid crystal display base plates are detected by placing an electro-optical element, in which the optical properties change when an electric field is applied thereto, over and facing a liquid crystal display base plate, energizing the leads of said display base plate, irradiating the base plate with a light beam through the electro-optical element, and converting the optical changes detected for each pixel element electrode into a voltage distribution. The testing method in this invention is capable of identifying not only whether or not a pixel element electrode is functional, but also if a functional pixel element electrode is functioning as desired or not. Application of the testing method of this invention is able to test liquid crystal display base plates, including those which show ambiguous display irregularities. Electro-optical elements change their optical properties when an electrical field is applied thereto.

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