Method and apparatus for automatically inspecting and repairing an active matrix LCD panel
First Claim
1. A method for inspecting an active plate having a pixel array, a plurality of pixel drive elements and a matrix of data lines and gate lines, each one pixel in the array being coupled on one gate line and one data line in the matrix by a pixel drive element, a plurality of data lines of the matrix terminating at a first shorting means, a plurality of gate lines terminating at a second shorting means, the method comprising the steps of:
- applying a first timing pattern to the first shorting means and second shorting means;
capturing a voltage image of a first area of the active plate from said step of applying said first timing pattern to obtain first pixel voltage data for pixels within said first area;
determining whether the active plate has more than a first number of defects based upon said first pixel voltage data;
and for an active panel having less than said first number of defects, applying a second timing pattern to the first shorting means and second shorting means;
capturing a second voltage image of a second area of the active plate from said step of applying said second timing pattern to obtain a second pixel voltage data for pixels within said second area; and
comparing the first pixel voltage data and the second pixel voltage data to identify a first pixel common to said first area and to said second area which has a short circuit to a data line.
2 Assignments
0 Petitions
Accused Products
Abstract
LCD panels are inspected in-process to measure pixel decay, turn-on time and parasitic capacitance and/or identify pixel defects and line defects. Prior to final assembly, panels identified as having sufficiently few repairable defects are repaired. Line defects may be repaired. Further pixel defects may be repaired when redundant structures are included by splicing out the defective TFT or storage capacitor and splicing in a redundant, built-in TFT or storage capacitor. The inspection and repair systems are linked through a repair file. The inspection system identifies each defect by type and location and includes such information in the repair file. The repair system accesses such file and follows a prescribed repair method for a given type of defect at the location of such defect. The inspection system includes an automated non-contact voltage imaging system. The repair system includes lasers and means for repairing defects by adding metallization.
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Citations
8 Claims
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1. A method for inspecting an active plate having a pixel array, a plurality of pixel drive elements and a matrix of data lines and gate lines, each one pixel in the array being coupled on one gate line and one data line in the matrix by a pixel drive element, a plurality of data lines of the matrix terminating at a first shorting means, a plurality of gate lines terminating at a second shorting means, the method comprising the steps of:
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applying a first timing pattern to the first shorting means and second shorting means; capturing a voltage image of a first area of the active plate from said step of applying said first timing pattern to obtain first pixel voltage data for pixels within said first area; determining whether the active plate has more than a first number of defects based upon said first pixel voltage data; and for an active panel having less than said first number of defects, applying a second timing pattern to the first shorting means and second shorting means; capturing a second voltage image of a second area of the active plate from said step of applying said second timing pattern to obtain a second pixel voltage data for pixels within said second area; and comparing the first pixel voltage data and the second pixel voltage data to identify a first pixel common to said first area and to said second area which has a short circuit to a data line. - View Dependent Claims (2, 3, 4)
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5. A method for identifying a pixel defect in an active LCD display having a pixel array, a plurality of pixel drive elements and a matrix of data lines and gate lines, each pixel being coupled to one gate line and one data line in said matrix, a plurality of data lines of said matrix including a termination at a first shorting means, a plurality of gate lines including a termination at a second shorting means, said method comprising steps of:
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applying a normal timing pattern to said first shorting means and said second shorting means; capturing a first voltage image of a first area of said active LCD display from said step of applying said normal timing pattern to obtain first pixel voltage data for pixels within said first area, said step of capturing said first voltage image of said first area identifying a pixel defect by non-activity of any pixel from said first pixel voltage data; applying a data-high timing pattern to said first shorting means and said second shorting means; capturing a second voltage image of a second area of said active LCD display from said step of applying said data-high timing pattern to obtain second pixel voltage data from pixels within said second area; comparing said first pixel voltage data to said second pixel voltage data; and identifying a location of said pixel defect comprising a short to pixel data defect from said step of comparing said first pixel voltage data to said second pixel voltage data, said pixel defect being common to said first area and said second area. - View Dependent Claims (6, 7, 8)
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Specification