Automatic dynamic pixel map correction and drive signal calibration

Abstract

To determine the pixel positions of a flat panel display, signals are applied to the gate lines and the data lines of the flat panel display without exciting the pixels. The gate lines and data lines have the same periodicity or pitch as the panel pixels but because the gate and data lines have narrower dimensions than the camera pixels, they provide sharper and more distinct signals. The intersections of the gate and data lines provide information about the position of the pixels. The pixel positions are subsequently used to generate a dynamic pixel map. Enhanced computational techniques use the pixel positions to determine the magnification of the imaging sensor head as well as the degree of rotation and offset of the panel pixel plane relative to the pixel plane of the imaging sensor head.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of US Provisional Application No. 61 / 100241, entitled "Automatic Dynamic Pixmap Correction and Drive Signal Calibration," filed September 25, 2008, the contents of which are hereby incorporated by reference in their entirety. technical field [0003] The present invention relates to the detection of defects during the manufacture of flat panel displays, more particularly during the array manufacturing steps of liquid crystal display panels. Background technique [0004] During the manufacture of flat-panel liquid crystal displays (LCDs), large transparent plates of thin glass are used as substrates for the deposition of thin-film transistor (TFT) arrays. Usually, several independent TFT arrays are contained within one glass substrate, and the several independent TFT arrays are often referred to as TFT panels. Alternatively, an active matrix LCD or AMLCD covers a type of display that...

AI Technical Summary

Problems solved by technology

A disadvantage of this approach is that (i) it is limited to certain types of LCD panels, and, (ii) to obtain the desired accuracy requires a large number of data samples and / or additional signal-to-noise filtering algorithms, both of which require more much time

The third is the distortion of the signal on and between pixel electrodes on a given pixel electrode due to bad materials and / or electrical effects

The fourth is the degradation of the signal on and between pixel electrodes at a given pixel electrode due to poorly aligned systems

However, because LCD and camera pixel electrodes are regular arrays, and because the two arrays have different pitches or periods, moire or interference patterns can result, especially if the pitch of the individual arrays is incomplete relative to each other

Furthermore, slight rotation of one array relative to the other results in disturbing patterns

This results in uneven signal strength from the LCD pixel electrodes within the array

[0023] One challenge in inspection and testing is to determine the position of the LCD pixel electrodes relative to the sensor's digital camera to enable further processing of the captured visual display or voltage images to extract defect information

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