Patent · US Expired

Testing device for liquid crystal display base plate

US5459409A · kind A · utility

25Cited by
45References
19Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 10, 1991
Grant dateOct 17, 1995
Priority date
Expiry dateSep 10, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N2021/9513
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The present invention provides an electro-optical element arranged to face a liquid crystal base plate, an electric source to impress an electric voltage between them, a source of light for irradiating light on the electro-optical element, a light detector to receive the reflected light from the electro-optical element, and a mounting device for fixing the liquid crystal base plate in a fixed position. The mounting device has a highly flat surface, groove thereon and vacuum attaches the liquid crystal base plate on the surface of the base platform. Light irradiates a reflective layer located on the lower surface of an electro-optical element which is in close proximity to the liquid crystal display base plate. A voltage is applied across the electro-optical element and the light reflected by the electro-optical element are measured. The optical characteristics of the electro-optical element is measured. The optical characteristics of the electro-optical element change in proportion to the electric field across it. The electric field is supplied in part by the liquid crystal display base plate being tested. Thus, by measuring the reflected light, the integrity of the liquid crystal …

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