Array test using the shorting bar and high frequency clock signal for the inspection of TFT-LCD with integrated driver IC
View Patent ↗In accordance with the present invention, a first shorting bar drives the data lines of a TFT array having integrated gate driver circuitry. Another set of shorting bars drive the corresponding terminals of the gate driver circuitry. The pixel voltages are measured after all the pixels are charged by the driving signals applied to the shorting bars. Gate voltages are progressively applied to the gate lines by the gate driver integrated circuit (IC) via the set of shorting bars that, in turn, are driven by clock signals received from one or more pattern generators. Voltages are concurrently applied to the data lines which are connected together by the first shorting bar. The application of voltages generates a display pattern that is subsequently compared to an expected display pattern. By comparing the resulting display pattern and the expected display pattern, possible defects are detected.
1. A method for testing a flat panel display comprising an active array matrix substrate, including a driver integrated circuit formed therein; the method comprising:
coupling a first shorting bar to a first plurality of clock input terminals of N successive registers disposed in the driver integrated circuit;
coupling a second shorting bar to a second plurality of clock input terminals of the N successive registers;
applying an enabling signal to an enable/disable terminal of a first register;
coupling an output terminal of the (i-1) register to an enable/disable terminal of the i register, wherein i is an integer varying from 2 to N;
applying a first clock signal to said first shorting bar;
applying a second clock signal to the second shorting bar, said second clock signal having 180 degrees phase shift with respect to the first clock signal;
applying outputs of the N registers to pixels disposed on the array; and
detecting differences between a resulting display pattern and an expected display pattern.
2. The method of claim 1 wherein said expected display pattern comprises expected image data, the method further comprising:
imaging a portion of said first resulting display pattern to generate sensed image data; and
comparing said sensed image data to the expected image data to detect differences therebetween.
3. The method of claim 1 further comprising:
coupling a third shorting bar to a first data input terminal;
coupling a fourth shorting bar to a second data input terminals;
applying a first data signal to the third shoring bar; and
applying a second data signal to the fourth shorting bar.
4. An apparatus for testing a flat panel display, said flat panel display comprising an active array matrix substrate including a driver integrated circuit formed therein, the apparatus comprising:
a first shorting bar adapted to be coupled to a first plurality of clock input terminals of N successive registers disposed in the driver integrated circuit;
a second shorting bar adapted to be coupled to a second plurality of clock input terminals of the N successive registers; wherein an enabling signal is applied to an enable/disable terminal of a first register, and wherein an output terminal of the (i-1) register is coupled to an enable/disable terminal of the i register, where i is an integer varying from 2 to N;
applying outputs of the N registers to pixels disposed on the array;
means for imaging the resulting display pattern to generate sensed image data; and
means for detecting differences between a resulting display pattern and an expected display pattern.
5. The apparatus of claim 4 wherein said expected display pattern comprises expected image data, the apparatus further comprising:
means for imaging a portion of said resulting display pattern to generate sensed image data; and
means for comparing said sensed image data to the expected image data to detect differences therebetween.
6. The apparatus of claim 4 further comprising:
a third shorting bar coupled to a first data input terminal and adapted to receive a first data signal; and
a fourth shorting bar coupled to a second data input terminal and adapted to receive a second data signal.