Testing method for imaging defects in a liquid crystal display substrate
US5504438A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1991 |
| Grant date | Apr 2, 1996 |
| Priority date | — |
| Expiry date | Sep 10, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/9513
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for testing liquid crystal display substrates with use of a testing apparatus which includes an electro-optical element. The test protocol includes applying a voltage between the circuitry on the liquid crystal display and the electro-optical element, irradiating the electro-optical element, evaluating performance under a variety of voltage conditions, and evaluating the corresponding response characteristics of the electro-optical element. The response characteristics are recorded by a plurality of CCD devices, each recording a different section of the panel. The changes in the magnitude of impressed voltage and polarity are synchronized with the recording timing. The recorded data is stored as frame memory which is subjected to frame by frame analysis to obtain quantitative information regarding the status of defective pixels. The resulting data is synthesized to obtain a composite performance picture of the entire panel which can be displayed as a unit to quickly obtain quantitative information regarding the overall defect presence. The technique is independent of the screen size, since the final large size screen image can be constructed from a plurality of smaller scr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.