JPH06175096A - Correction method for liquid crystal display - Google Patents

Abstract

PURPOSE:To correct a defective picture element without incorporating evaporated matter, etc., into a liquid crystal and without increasing the defective picture elements by giving damages to the other picture elements. CONSTITUTION:A polarizing plate 14 corresponding to the defective pixel electrode 4-2 among the respective pixel electrodes 4-1, 4-2, 4-3 of the liquid crystal display is subjected to surface working A by irradiating this plate with a laser beam. The incident light on this surface worked A part is scattered and the light to a color filter 7-2 and the pixel electrode 4-2 is shut off, by which the luminescent point defective picture element is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display repairing method for repairing bright spot defective pixels using laser light.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a liquid crystal display. The glass substrates 1 and 2 are supported by a support 3 and are arranged to face each other. Of the glass substrates 1 and 2, the pixel electrodes 4-1, 4-2, ... Are arranged on the glass substrate 1 at predetermined intervals and the pixel electrodes 4-1 and 4- are arranged.
The thin film transistors 5-1, 5-2, ... Are connected to 2 ,. Then, these pixel electrodes 4-1, 4-2,
The alignment film 6 is formed on the thin film transistors 5-1, 5-2, ...

Further, on the other glass substrate 2, color filters 7-1, 7-2, ... Of the three primary colors of light are arranged at positions corresponding to the pixel electrodes 4-1, 4-2 ,. Further, the common electrode 8 and the alignment film 9 are formed on the upper part thereof. Then, the liquid crystal 10 is sealed between the alignment films 6 and 9. Further, each spacer 1 is provided between the alignment films 6 and 9.
1 and 12 are arranged. On the other hand, each glass substrate 1, 2
Polarizing plates 13 and 14 are attached to the outside of the.

With such a configuration, each color filter 7
A backlight is arranged on the glass substrate 2 side (downward in the figure) on the side where -1, 7-2, ... Are formed, and the light Q with uniform light intensity is emitted from this backlight. In this state, for example, the thin film transistor 5-1 becomes conductive and the pixel electrode 4-1.
When a voltage is applied between the pixel electrode 4-1 and the common electrode 8, the pixel electrode 4-1 and the common electrode 8 are shielded from light, while the voltage is applied between the pixel electrode 4-1 and the common electrode 8. When the light is cut off, the light Q is transmitted between the pixel electrode 4-1 and the common electrode 8. The operation of such a liquid crystal display is called normally white.

However, in the process of manufacturing such a liquid crystal display, when the liquid crystal 10 is sealed, the conductive foreign metal 15 may be mixed. If such a metal foreign substance 15 is mixed and sandwiched between the pixel electrode 4-2 and the common electrode 8, for example, the pixel electrode 4-2 and the common electrode 8 are short-circuited. In addition, each pixel electrode 4-1
There may be a short circuit on the wirings 4-2, .... If such a short circuit occurs, it becomes difficult to control the conduction of each thin film transistor 5-1, 5-2 ,.
A state in which the light Q always passes through the portion of the pixel electrode 4-2, that is, a so-called bright spot defective pixel is obtained. Thus, the liquid crystal display having the bright spot defective pixel is treated as a defective product and excluded from the product.

Therefore, the bright spot defective pixel in the liquid crystal display is repaired. In this method, the metal foreign matter 15 is directly irradiated with laser light to be destroyed,
The pixel electrode 4-2 is irradiated with the laser light on the ring to remove it in a ring shape as shown in FIG. 6, and the small portion 4a is electrically insulated to form the bright spot defective pixel. A method of reducing to a small portion 4a is performed.

However, in the method of irradiating the inside of the liquid crystal display with the laser beam as in the above method, bubbles may be generated in the liquid crystal 10 by the irradiation of the laser beam and the vaporized substance may be mixed therein. When vaporized substances are mixed in this way,
The brightness of each pixel is affected.

Further, in particular, in the method of directly irradiating the metallic foreign matter 15 with laser light to destroy and finely decompose it, the metallic foreign matter 1
5 will not be destroyed and will move to another place, or the fragments of the destroyed metal foreign matter 15 will be scattered and rather the number of bright spot defective pixels will increase.

[0009]

As described above, the liquid crystal 10 is used.
When vaporized substances are mixed in, the brightness of each pixel is affected. In addition, the metallic foreign matter 15 moves to another place without being destroyed, or the fragments thereof are scattered and the bright spot defective pixels are increased.

Therefore, the present invention provides a method for repairing a liquid crystal display, which is capable of repairing a bright spot defective pixel without mixing vaporized substances into liquid crystal and damaging other pixels to increase bright spot defective pixels. The purpose is to provide.

[0011]

According to a method of repairing a liquid crystal display of a first aspect of the present invention, one of the substrates of the pixel electrodes of the liquid crystal display corresponding to the bright spot defective pixel is one of the substrates. The surface is processed by irradiating the side with laser light.

In the liquid crystal display repairing method according to the second aspect of the present invention, a black dot is painted on one of the substrates of the pixel electrode corresponding to the bright spot defective pixel. is there.

Further, in the liquid crystal display repairing method of the third invention, a black dot is painted on one of the substrates of the part of each pixel electrode corresponding to the bright spot defective pixel, and a black dot is applied. That is, a part of the black dots is removed by laser light to form a shape corresponding to the pixel electrode.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. The same parts as those of the present invention are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a block diagram of a correction device for a liquid crystal display. A hollow hole 21 is formed in the center of the XY table 20, and the transillumination unit 2 is provided below the hollow hole 21.
2 are arranged. The transillumination unit 22 is arranged so as to emit white light P1 having a uniform light intensity toward the hollow hole 21.

Further, the XY table 20 is provided with a processing moving mechanism 23. This processing movement mechanism 23
The XY table 20 is moved and controlled on the XY plane, and this XY table is moved.
The position of the liquid crystal display 30 placed on the table 20 is controlled.

The structure of the liquid crystal display 30 mounted on the XY table 20 is the same as that shown in FIG. 5, and the mounting direction is opposite to that shown in FIG. 5 in the vertical direction. ing. A liquid crystal display driving device 31 is connected to the liquid crystal display 30. The liquid crystal display driving device 31 supplies a drive control signal to the thin film transistors 5-1, 5-2, ... Of the liquid crystal display 30 so as to connect the pixel electrodes 4-1, 4-2 ,. It has the function of controlling the applied voltage.

An image forming optical system 50 is arranged above the XY table 20. In this image forming optical system 50, a condenser lens 51 is arranged, and a dichroic mirror 52, a beam splitter 53, and an image forming lens 54 are arranged on the optical axis of the condenser lens 51. Of these, an epi-illumination source 55 is arranged in the branching direction of the beam splitter 53. The CCD camera 56 is located at the image forming point of the image forming lens 54.
Is arranged, and the image signal output from the CCD camera 56 is sent to the monitor television 57. The condensing point of the condensing lens is on the polarizing plate 14 of the liquid crystal display 30 as shown in FIG.

On the other hand, a laser oscillator 60 is provided, to which a laser power source 61 is connected. The laser oscillator 60 has a function of generating pulsed YAG laser light and converting the pulsed YAG laser light into a fourth harmonic (FHG) for output.

The pulsed laser light output from the laser oscillator 60 is reflected by the mirror 62 and the beam splitter 63 and enters the dichroic mirror 52.

Further, a white light source 64 for positioning is provided, and the white light emitted from the white light source 64 is reflected by the lens 6.
The light is converted into parallel light by 5 and propagates through the same optical path as the optical path of the pulsed laser light from the beam splitter 63 and enters the dichroic mirror 52. Next, a method of repairing the liquid crystal display 30 using the device configured as described above will be described.

The liquid crystal display 30 is an XY table 20.
The white light P1 placed on the top and emitted from the transmissive illumination unit 22 propagates through the hollow hole 21 and is applied to the liquid crystal display 30.

At the same time, the incident light P2 emitted from the incident illumination source 55 is split by the beam splitter 53,
The light passes through the dichroic mirror 52, is condensed by the condenser lens 51, and is irradiated onto the liquid crystal display 30. Then, this reflected light passes through a condenser lens 51, a dichroic mirror 52, and a beam splitter 53, and an imaging lens 5
An image is formed on the image pickup surface of the CCD camera 56 by 4. The CCD camera 56 receives the reflected light, captures an image of the liquid crystal display 30, and outputs the image signal to the monitor television 5.
Send to 7. As a result, the monitor image on the liquid crystal display 30 is displayed on the monitor television 57.

In this state, the machining moving mechanism 23 moves the XY table 20 on the XY plane. The movement of the XY table 20 moves the area of the liquid crystal display 30 which is imaged by the CCD camera 56, and the monitor image of the monitor television 57 changes accordingly.

When a bright spot defective pixel, that is, a pixel in which the foreign metal 15 is mixed is detected from this monitor image, white light is emitted from the white light source 64, and this light is emitted from the condenser lens 5.
The polarizing plate 14 of the liquid crystal display 30 is condensed by 1
Irradiated on. Then, the reflected light is collected by the condenser lens 5.
1 to dichroic mirror 52, beam splitter 5
The light is received by the imaging lens 54 through 3 and is displayed on the monitor image of the monitor television 57. Therefore, the monitor image is monitored, and the XY table 20 is moved and controlled by the processing moving mechanism 23 to align the irradiation position of the white light with the bright point defective pixel.

After this alignment, the laser oscillator 60
Outputs the pulsed YAG laser light converted into the fourth harmonic. The pulsed YAG laser light is reflected by the mirror 62 and the beam splitter 63 and is reflected by the dichroic mirror 5.
2, the light is further condensed by the condenser lens 51, and is irradiated onto the polarizing plate 14 of the liquid crystal display 30 as shown in FIG.

At this time, XY is moved by the processing moving mechanism 23.
The table 20 is moved and controlled to scan the irradiation position of the pulsed YAG laser light on the portion corresponding to the color filter 7-2 of the bright spot defective pixel. In this case, since the irradiation position of the pulse YAG laser light and the irradiation position of the white light coincide with each other, the pulse YAG laser light can be scanned by monitoring the white light position on the monitor image. The polarizing plate 14 of the liquid crystal display 30 is subjected to the surface processing A by the heat of the pulse YAG laser light by the irradiation of the pulse YAG laser light and the scanning thereof.

As a result, the light incident on the surface-processed portion of the polarizing plate 14 is scattered, so that the light to the color filter 7-2 and the pixel electrode 4-2 is the same as the light shielded. It becomes a state. Therefore, even if a bright spot defect occurs in the pixel electrode 4-2, this bright spot defect pixel does not appear on the screen of the liquid crystal display 30.

As described above, in the first embodiment, the pulse YAG is applied to the portion of the polarizing plate 14 corresponding to the bright spot defective pixel.
Since the surface processing A is performed by irradiating with laser light,
As described above, the light incident on the surface-processed portion A is scattered and color filter 7-2 and pixel electrode 4-2.
The light is in the same state as when it is shielded, and even if a bright spot defective pixel occurs in the pixel electrode 4-2, this bright spot defective pixel does not appear on the screen of the liquid crystal display 30.

Further, according to this repairing method, bright spot defective pixels can be easily repaired without mixing vaporized substances into the liquid crystal 10 and damaging other pixels to increase defective pixels. Thereby, the product yield in manufacturing the liquid crystal display 30 can be improved. Next, a second embodiment of the present invention will be described.

When it is detected from the monitor image of the monitor television 57 of the above apparatus that the liquid crystal display 30 has a bright spot defective pixel, the bright spot defective pixel portion on the surface of the liquid crystal display 30 is detected as shown in FIG. Black paint on 7
0 is applied. The material of the black dot coating point 70 may be any material that blocks light. Due to the application of the black-painted spot 70, the bright-spot defect pixel does not appear on the screen of the liquid crystal display 30.

By the way, the black coating points 70 are not applied only to the regions corresponding to the color filter 7-2 and the pixel electrode 4-2 which are the bright spot defective pixels, but the adjacent black color filters as shown in FIG. It may be applied up to the areas corresponding to 7-1 and 7-3.

Therefore, the monitor image is monitored in the same manner as described above, and the processing moving mechanism 23 controls the movement of the XY table 20 to align the irradiation position of the white light with the black coating point 70.

After this alignment, the laser oscillator 60 outputs the pulsed YAG laser light converted into the fourth harmonic, and the pulsed YAG laser light is condensed by the condenser lens 51, as shown in FIG. The black coating point 70 on the polarizing plate 14 of the liquid crystal display 30 is irradiated.

At this time, XY is moved by the processing moving mechanism 23.
The table 20 is moved and controlled, and the irradiation position of the pulsed YAG laser light is scanned on the black coating point 70 except the portion corresponding to the color filter 7-2. By the irradiation of the pulsed YAG laser light and the scanning thereof, the black coating point 70 becomes the pulse YA.
Only the dye is evaporated and removed by the heat of the G laser light. As a result, the color filter 7-
2 and the black coating point 7 only in the area corresponding to the pixel electrode 4-2.
0 remains.

As described above, in the second embodiment, the black dot coating point 70 is formed on the portion of the polarizing plate 14 corresponding to the bright point defective pixel.
Since a part of the black spot coating point 70 is removed by laser light to form a shape corresponding to the bright spot defective pixel, the bright spot defective pixel is darkened and the bright spot defective pixel becomes a liquid crystal. The bright spot defective pixel can be easily corrected without appearing on the screen of the display 30, and without causing vaporization or the like to be mixed into the liquid crystal 10 and damaging other pixels to increase the number of defective pixels. Thereby, the product yield in manufacturing the liquid crystal display 30 can be improved. The present invention is not limited to the above-mentioned embodiments, and may be modified within the scope of the invention.

For example, when performing surface processing, instead of focusing the laser light, the laser may be applied to a wide area using a slit or the like, and the wide area may be collectively surface-processed A. .

Further, in each of the above-mentioned embodiments, the surface processing A was performed on the polarizing plate 14 on the side where the backlight of the liquid crystal display 30 is arranged, or the black dot coating point was applied, but the surface is applied to the polarizing plate 13 on the opposite side. Processing A may be performed or a black dot coating point may be applied.

[0039]

As described above in detail, according to the present invention, it is possible to prevent the occurrence of bright spot defective pixels without mixing vaporized substances into the liquid crystal and damaging other pixels to increase bright spot defective pixels. A method of correcting a liquid crystal display that can be corrected can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a correction device to which a liquid crystal display correction method according to the present invention is applied.

FIG. 2 is a diagram showing a correcting action by surface processing of laser light of the same apparatus.

FIG. 3 is a diagram showing black dot coating points in the second embodiment of the present invention.

FIG. 4 is a diagram showing a black dot coating point removing action in the embodiment.

FIG. 5 is a diagram showing a state where a metallic foreign substance is sandwiched between liquid crystal displays.

FIG. 6 is a diagram showing a correcting action of a bright spot defective pixel by a metallic foreign matter of a conventional liquid crystal display.

[Explanation of symbols]

1, 2 ... Glass substrate, 4-1 to 4-3 ... Pixel electrode, 5-
1-5-3 ... Thin film transistor, 7-1-7-3 ... Color filter, 8 ... Common electrode, 10 ... Liquid crystal, 13, 14 ...
Polarizer, 15 ... Metal foreign matter, 20 ... XY table, 22 ...
Transmitted illumination unit, 23 ... Moving mechanism for processing, 30 ... Liquid crystal display, 31 ... Liquid crystal display drive device, 50
... Imaging optical system, 51 ... Condensing lens, 56 ... CCD camera, 57 ... Monitor television, 60 ... Laser oscillator,
64 ... White light source.

Claims (3)

[Claims] 1. A method of repairing a liquid crystal display, comprising enclosing a liquid crystal between opposed substrates and arranging each pixel electrode on one of the substrates, wherein a bright spot defective pixel among the pixel electrodes is provided. 2. A method for repairing a liquid crystal display, which comprises irradiating a laser beam on one of the substrates of the respective portions corresponding to the above to perform surface processing. 2. A method of repairing a liquid crystal display in which liquid crystal is sealed between opposed substrates and each pixel electrode is arranged on one of these substrates, wherein a bright spot defective pixel among the pixel electrodes is provided. 5. A method of repairing a liquid crystal display, characterized in that a black dot is painted on one of the substrates in the portion corresponding to [1]. 3. A method of repairing a liquid crystal display, wherein liquid crystal is sealed between opposed substrates and each pixel electrode is arranged on one of the substrates, wherein bright pixel defective pixels among the pixel electrodes are provided. A black dot is painted on one of the substrates of the portion corresponding to the above, and a part of the black dot is removed by laser light to form a shape corresponding to the pixel. How to fix the LCD display.