Method of testing active matrix liquid crystal display substrates
US5432461A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1991 |
| Grant date | Jul 11, 1995 |
| Priority date | — |
| Expiry date | Jun 28, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S345/904
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A testing method for active matrix liquid crystal display substrates having thin film transistors provided with a plurality of pixel electrodes, a plurality of source lines, and a plurality of gate lines formed on a substrate. A high resolution electro-optical element whose optical properties change when an electrical field is impressed on it is disposed above the active matrix liquid crystal display substrate and separated therefrom by an extremely small gap. Electric current is caused to flow between the pixel electrodes on the active matrix liquid crystal display substrate and the transparent thin film electrodes on the surface of the electro-optical element, creating an electrical field in the electro-optical element. By detecting local changes in the optical properties of the electro-optical element, defects in the pixels of the active matrix liquid crystal display substrate can be detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.