Method and apparatus for testing LCD panel array prior to shorting bar removal
US5081687A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1990 |
| Grant date | Jan 14, 1992 |
| Priority date | — |
| Expiry date | Nov 30, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S345/904
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Final testing of an LCD panel or the like is performed after preliminary testing for short circuit defects. During final testing, the panel is exposed to signals at the shorting bars and the resulting display pattern is imaged. The resulting image data then is processed at a computer system to determine whether the resulting display pattern differs from an expected display pattern. If differences are present then an open circuit or pixel defect is present. The applied test signals and the pattern or differences determine the type of defect present. For an open circuit defect along a gate line, a partial row (column) of the resulting display pattern does not activate. For an open circuit along a drive line, a partial column (row) of the resulting display does not activate. Pixel shorts are identified by applying test signals to the shorting bars during a first test cycle, then imaging the display during a second test cycle after at least one of the test signals is removed. Pixels which remain active that should be inactive have short circuit defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.