KR20020063371A - Lcd pannal tester - Google Patents

Abstract

PURPOSE: A device for inspecting an LCD(Liquid Crystal Display) panel is provided to inspect the abnormality of a cathode ray tube which radiates backlight to an LCD panel in advance for preventing the mistake in the judgement for LCD panel rejects due to the bad cathode ray tube. CONSTITUTION: A device for inspecting an LCD panel includes a power supply(100), a relay part for supplying a driving voltage supplied from the power supply or stopping the supply thereof, a backlight part(120) to be turned on by the driving voltage supplied from the relay part for outputting light signals, an illumination intensity detecting part(130) for detecting the intensity of illumination of the light signals radiated from the backlight, digital signal processing parts(140) for converting an illumination intensity signal output from the illumination intensity detecting part to digital signals to output, and a computer(150) for controlling the displaying or testing operation of the signals output from the digital signal processing part.

Description

Liquid crystal display panel inspection device {LCD PANNAL TESTER}

The present invention relates to a liquid crystal display panel inspection apparatus, and more particularly, in an inspection apparatus for inspecting whether a liquid crystal display panel is defective, by inspecting in advance whether there is an abnormality of a cathode ray tube irradiating a backlight to the liquid crystal display panel. The present invention relates to a liquid crystal display panel inspection apparatus for preventing a misjudge of a liquid crystal display panel caused by a failure of the cathode ray tube.

In general, a liquid crystal display panel inspection apparatus includes an apparatus for inspecting by an electric signal, and an apparatus for inspecting by using an optical signal. An apparatus for inspecting an electrical signal includes a plurality of gate lines parallel to each other on a quartz substrate. A plurality of data lines arranged in parallel with the gate lines, and a thin film transistor connected to the intersection of the gate line and the data line, and a plurality of pixels connected to the drain terminal of the thin film transistor in a matrix form. An apparatus for inspecting line defects or pixel defects in a liquid crystal display panel, the line defects are inspected for disconnection, and thus the inspection can be easily conducted by conduction or non-conduction.

The pixel defect is inspected as an open defect or a short circuit defect. The pixel defect is easily inspected for a short circuit defect in an output level state of the selected pixel by sequentially selecting the image display mode of the scanning timing generator. In this case, since the signal-to-noise ratio is poor due to the stray capacitance of each pixel line, the accuracy of the determination decreases, so that the stray capacitance is completely inspected.

The inspection apparatus using the optical signal inspects the uneven state of the liquid crystal display panel, and inspects the uneven display defect by acquiring the contrast of the liquid crystal display panel through the camera using a polarizer, a backlight, and a camera. Will be done.

As described above, in the case of a device for inspecting whether a liquid crystal display panel is defective due to the display unevenness, when the backlight irradiates light to the liquid crystal display panel, that is, when the cathode ray tube is defective or abnormally lit or partially lowered in luminance, The display panel appears as a stained phenomenon. At this time, the inspector is inferior to the spot phenomenon appearing on the liquid crystal display panel.

Of course, the appearance of the liquid crystal display panel in the form of a stain may be natural to be treated as a defect, for example, one of the plurality of cathode ray tubes, such as a defect or lighting abnormality, the luminance is not abnormal due to the lowered brightness. Nevertheless, when the stain is continuously present, the inspector treats the liquid crystal panel as a defect, thereby increasing the defect rate of the liquid crystal panel, thereby causing economic losses.

Accordingly, an object of the present invention is to check whether there is a problem with the backlight before checking whether there is a defect in the liquid crystal display panel, and then check whether there is a problem with the liquid crystal display panel, thereby causing a problem of the backlight. The aim is to reduce defect rates and minimize economic losses.

The present invention provides a power supply device for realizing the above object; A relay unit which supplies and cuts off driving voltage supplied from the power supply device; A backlight unit which outputs an optical signal while being turned on by a driving voltage supplied from the relay unit; An illuminance detection unit detecting an illuminance of the optical signal emitted from the backlight unit; A digital signal processor for converting an illuminance signal detected by the illuminance detector into a digital signal and outputting the digital signal; It is characterized in that the computer is configured to control the display and test operation by receiving the signal input from the digital signal processor.

1 is an overall block diagram of the liquid crystal display panel inspection apparatus of the present invention

2 is a detailed circuit diagram of a liquid crystal display panel inspection device of the present invention.

3 is a display of abnormality of the liquid crystal display panel inspection device of the present invention

* Explanation of symbols for the main parts of the drawings *

100; A power supply unit 110; Relay part

120; Backlight 130; Illumination detector

140; A digital signal converter 150; computer

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention.

1 is an overall block diagram of a liquid crystal display panel inspection device of the present invention, and FIG. 2 is a detailed circuit diagram of the liquid crystal display panel inspection device of the present invention, comprising: a power supply device 100 for supplying a stable driving voltage to the device; A relay unit 110 for supplying and blocking driving the driving voltage supplied from the power supply device 100; A backlight unit 120 outputting an optical signal while being turned on by a driving voltage supplied from the relay unit 110; An illuminance detector (130) for detecting illuminance of an optical signal emitted from the backlight unit (120); A digital signal processor 140 for converting the illuminance signal detected by the illuminance detector 130 into a digital signal and outputting the digital signal; The computer 150 is configured to receive a signal input from the digital signal processor 140 and control display and test operations.

The backlight unit 120 may be configured as a cathode ray tube, and the cathode ray tube may be variably installed according to the size of the liquid crystal display panel.

The illuminance detection unit 130 is composed of a photoconductive cell (Cds) element, a plurality of the photoconductive cell (Cds) is installed in a position that can easily detect the entire optical signal of the backlight unit 120 Done.

The digital signal processor 140 is configured as an A / D converter that converts an input analog signal into a digital signal and outputs the digital signal.

The computer 150 includes a microprocessor for temporarily controlling or sequentially controlling the entire backlight and a monitor for displaying the number of cathode ray tubes of the backlight unit 120.

According to the present invention configured as described above, the driving voltage is supplied from the power supply unit 100 to the inspection apparatus, and then the inspector checks whether the liquid crystal display panel is defective or not through the computer 150. When any one of the cathode ray tubes of the mounted backlight unit 120 is inspected as shown in FIG. 3 in order to check for defects, lighting abnormalities, and luminance deterioration, the microprocessor of the computer 150 sets a predetermined algorithm. By the relay unit 110 to output a drive signal for a predetermined time set arbitrarily.

At this time, the computer 150 applies a driving signal to all of the relays RY1 to RY59 of the relay unit 110 by a predetermined algorithm, or sequentially drives them.

Accordingly, the relays RY1 to RY59 of the relay unit 110 all or sequentially turn on the relay contacts to apply the driving voltage applied from the power supply unit 100 to the cathode ray tube of the backlight unit 120. Or it turns on sequentially.

As described above, in the process of turning on the cathode ray tube of the backlight unit 120, the photoconductive cell of the illuminance detector 130 mounted at both sides of the backlight unit 120 detects the optical signal of the illuminated cathode ray tube. Done.

The illuminance signal detected by the illuminance detector 130 is converted into a digital signal through a digital signal converter 140 and is input to the computer 150, and the computer 150 is input by a predetermined algorithm. The digital signal (detected illuminance signal) is controlled to display the detected illuminance of the cathode ray tube of the backlight unit 120 displayed as shown in FIG. 3 through the monitor.

Therefore, the inspector easily checks the illumination state of the cathode ray tube of the backlight displayed on the monitor of the computer 150, and easily confirms which cathode ray tube has occurred in the backlight unit 120.

At this time, if no abnormality is detected in the cathode ray tube of the backlight unit 120, the inspector determines whether there is no abnormality in the backlight unit 120, and applies the backlight to the liquid crystal display panel transferred from a separate transfer device. It is possible to inspect whether or not the LCD panel is defective while inspecting.

As described above, according to the present invention, after checking whether there is an abnormality of the backlight for irradiating an optical signal before checking whether there is a defect of the liquid crystal display panel, if there is no abnormality of the backlight, the liquid crystal display panel is inspected for defects. By starting to reduce the bad occurrence of the liquid crystal display panel caused by the abnormality of the backlight to provide an effect that can minimize unnecessary economic losses.

Claims (4)

A power supply; A relay unit which supplies and cuts off driving voltage supplied from the power supply device; A backlight unit which outputs an optical signal while being turned on by a driving voltage supplied from the relay unit; An illuminance detection unit detecting an illuminance of the optical signal emitted from the backlight unit; A digital signal processor for converting an illuminance signal detected by the illuminance detector into a digital signal and outputting the digital signal; And a computer for controlling and displaying a signal input from the digital signal processor. 2. The liquid crystal display panel inspection apparatus according to claim 1, wherein the backlight unit is constituted by a cathode ray tube, and the mounting number is variably configured according to the size of the liquid crystal display panel. 2. The liquid crystal display panel inspection apparatus according to claim 1, wherein the illuminance detection unit is formed of a photoconductive cell element, and a plurality of illuminance detection units are provided on both sides of the backlight unit so as to detect the entire optical signal. 2. The liquid crystal display panel inspection apparatus according to claim 1, wherein the computer is configured to turn on all of the backlight units at once or turn them on sequentially.