
US Patent No: 5,309,108
Number of patents in Portfolio can not be more than 2000
Method of inspecting thin film transistor liquid crystal substrate and apparatus therefor
Stats
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May 3, 1994
Issued date -
Jul 30, 1992
filing date -
07/921,583
serial no -
In Force
status
Importance
Abstract
The invention relates to a method of inspecting and correcting a thin film transistor liquid crystal substrate and an apparatus therefor, where a plurality of scan lines and signal lines are connected electrically in common at each one terminal side respectively, and an infrared image outside the pixel domain is detected after lapse of a prescribed time from the time point of applying voltage between the scan lines and the signal lines, and an infrared image outside the pixel domain is detected after lapse of a prescribed time from the time point of stopping the voltage application, and the scan lines and the signal lines relating to variation of the heating state are detected from difference or quotient between an infrared image at the voltage applying state and an infrared image at the stopping state of voltage application, thereby a pixel address with a shortcircuit defect occurring is specified. If an image part being equal to the set threshold value or more does not exist in the difference infrared image in the pixel address, a wiring pattern position in the pixel address is detected from a visible image of the pixel address, and this wiring pattern and one from a neighboring pixel address are compared to detect a short circuit defect which can be removed by laser.
First Claim
Related Publications
International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
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| 5,073,754 Method and apparatus for testing LCD panel array using a magnetic field sensor | 17 | 1990 | |
| 5,175,504 Method and apparatus for automatically inspecting and repairing a simple matrix circuit panel | 21 | 1991 | |
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| 5,057,775 Method of testing control matrices for flat-panel displays | 19 | 1990 | |
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| 5,146,509 Method of inspecting defects in circuit pattern and system for carrying out the method | 30 | 1990 | |
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| 4,628,531 Pattern checking apparatus | 76 | 1984 | |
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| 4,940,934 Method of electrically testing active matrix substrate | 16 | 1988 | |
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| 4,843,312 Test method for LCD elements | 35 | 1988 | |