JP2955079B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal display equipment to correct defects such as bright spot defective pixel.

[0002]

2. Description of the Related Art In recent years, a liquid crystal display panel has been used in a projection apparatus for enlarging and projecting an image on a screen. In this projection device, display illumination light is emitted from one surface of a transmissive liquid crystal panel in which display pixels are arranged in a matrix, and emission light emitted from the other surface is enlarged and projected on a screen to display an image. .

An example of a liquid crystal panel used in the above-mentioned projection device is an active matrix driving type liquid crystal panel. In this liquid crystal panel, a TFT (thin film transistor) is connected to a pixel electrode arranged in a matrix on one of a pair of translucent substrates made of glass or the like to be bonded, and a switching operation of the TFT is performed. The display operation is performed by selecting and non-selecting each pixel electrode. For this reason, crosstalk during non-selection, which is a drawback of the simple matrix driving method, does not occur, and a high-quality display screen can be realized.

Since the TFT has a multilayer structure in which a gate electrode, a source electrode, a drain electrode and the like are laminated on a substrate, a step of laminating these metal thin films on the substrate,
The step of patterning the metal thin film is repeatedly performed. Therefore, in order to produce a complete TFT without defects, a great effort is required to maintain and manage various setting conditions in each manufacturing process.

Therefore, in some cases, a normal TFT
In some cases, defective TFTs for which characteristics have not been obtained may occur, and repairable defects can be repaired using the respective repair techniques depending on the content of the defect. Such a T
As an example of a defect of the FT, when a display cannot be repaired on a circuit formation pattern and a display is driven, a pixel corresponding to a pixel electrode connected to the TFT becomes a bright point and is recognized on a display screen as a bright spot. There are point defects.

In order to prevent the occurrence of defective picture elements as described above, conventionally, for example, two wirings are connected to each pixel electrode, and even if one wiring is broken, the display is not affected. Like that. In addition, each pixel is divided into two, and one pixel is displayed by a plurality of electrodes. When a voltage cannot be applied to one electrode, the pixel is displayed by the remaining electrodes.

[0007]

In a liquid crystal display device in which two wirings are connected to each pixel or one pixel is divided into two to display one pixel with a plurality of electrodes, the driving circuit is complicated. And it is difficult to design and manufacture the circuit. In addition, since the circuit becomes complicated and the number of wirings increases, the area in which the wirings are formed must be increased, and the area of each electrode is reduced, and there is a problem in that the display brightness is reduced.

In addition, when one pixel is displayed by a plurality of electrodes, there is a problem that a load is applied to a driving circuit for performing display.

Further, even when the conventional technique as described above is used, if any of the two wirings connected to each pixel is broken, the wiring is connected to each of a plurality of electrodes for displaying one pixel. If any of the wiring
The generation of bright spots cannot be prevented.

An object of the present invention is to provide a liquid crystal display device which prevents light from leaking from a region corresponding to a defective pixel and improves display quality, and a method of manufacturing the same.

[0011]

[0012]

According to the present invention, there is provided a method of manufacturing a liquid crystal display device in which a liquid crystal layer is interposed between a pair of light transmitting substrates and a plurality of pixels are formed in a matrix. Coating means is formed on at least one surface of the non-conductive substrate on the side opposite to the liquid crystal layer, on the optical path of incident light and outgoing light, and on the side of the one substrate on which the coating means is formed; Forming a recess in a region corresponding to the above, filling the recess with a light-blocking resin, and peeling off the covering means.

[0013]

According to the present invention, the light leaking from the area corresponding to the defective pixel is shielded by the light shielding means provided on the optical path of the incident light and the emitted light and provided in the area corresponding to the defective pixel. Therefore, it is possible to prevent light from leaking from the region corresponding to the defective pixel, and it is possible to significantly improve display quality. In particular, according to the present invention, at least one of the pair of light-transmitting substrates is provided with a light-shielding means, that is, the light-shielding means is provided on one or both of the substrates, as described above. The distance between the pixel and the area corresponding to the defective pixel can be reduced. As a result, even when the viewing angle is inclined, the light that has passed through the area corresponding to the defective pixel can be blocked by the light blocking means, and is not recognized as leakage light.

According to the invention, a coating means is formed on a surface of at least one of the pair of translucent substrates constituting the liquid crystal display element, the surface being opposite to the liquid crystal layer. Forming a recess in the area corresponding to the defective pixel,
The concave portion is filled with a light-shielding resin, and finally, the covering means is peeled off to form a liquid crystal display device. Thus, light leaking from the area corresponding to the defective pixel is shielded by the light-shielding resin filled in the recess provided in the area corresponding to the defective pixel. Therefore, light leakage from a region corresponding to the defective pixel can be prevented, and the display quality of the liquid crystal display device can be improved.

When the recess is filled with the light-shielding resin, the resin overflows around the recess, and when the overflowed resin is removed, the resin is excessively filled by the thickness of the covering means. Therefore, by adjusting the thickness of the coating means,
The resin filled in the recess can be removed so that the thickness of the resin does not become thin at the center, and the thickness of the light-shielding resin can be adjusted so as to rise from the substrate surface.

[0016]

FIG. 1 is a sectional view showing the structure of a liquid crystal display device 1 according to one embodiment of the present invention. The liquid crystal display device 1 has transparent substrates 2 and 3 made of glass or the like having a light-transmitting property disposed facing each other, and a surface of the transparent substrate 2 facing the transparent substrate 3 is made of ITO (indium tin oxide) or the like. A single full-surface electrode 4 is formed, and an alignment film 5 made of a resin such as polyimide is formed on the surface. On the surface of the transparent substrate 3 facing the transparent substrate 2, a plurality of rectangular pixel electrodes 6 are arranged in a matrix, and an alignment film 7 is formed on the surface.

The transparent substrates 2 and 3 are arranged so that the surfaces on which the electrodes 4 and 6 are formed face each other, and are configured with a liquid crystal layer 8 interposed between the substrates. Each of the pixel electrodes 6 is connected to a TFT (not shown).

In the liquid crystal display device 1, a region where the full-surface electrode 4 and the pixel electrode 6 overlap is defined as a pixel region. In this embodiment, the pixel electrode 6a is connected to the line disconnection or T
A normal drive voltage cannot be applied to the corresponding liquid crystal layer 8 due to the FT characteristic failure or the like, and the region A1 including the pixel electrode 6a becomes a defective pixel region. The defective pixel area A1
Can perform only light-transmitting display irrespective of application / non-application of a voltage to the pixel electrode 6a. Therefore, when a voltage is applied to the surrounding pixel electrode 6, the surrounding pixel area blocks light but the defective pixel area A1
In this case, since light is transmitted, it becomes a bright point, and the display quality is reduced. In the present invention, as shown in FIG.
In addition, by providing the light shielding means 9, the defective pixel area A
1 does not transmit light, and is prevented from becoming a bright spot.

The light shielding means 9 may be formed on the substrate 3 or on both the substrates 2 and 3.

FIG. 2 is a diagram for explaining an example of use of the liquid crystal display device 1. Here, the liquid crystal display device 1 is used as a display panel of a so-called projection display device. Light source light 11 from a light source (not shown) is
2, the light enters from the transparent substrate 2 side of the liquid crystal display device 1 as a display panel, and the light emitted from the transparent substrate 3 side is applied to a screen (not shown) via the projection lens 13. Thereby, the image displayed on the liquid crystal display device 1 is enlarged and projected on the screen.

At this time, as shown in FIG. 1, a light shielding means 9 is provided on the optical path of the light incident on the defective pixel area A1, and the incident light is shielded. Therefore, the emitted light 14 from the defective pixel area A1 is not irradiated on the screen, and is not displayed as a bright spot in the enlarged and projected image.

As described above, in the projection display device, even if the bright spot is a small bright spot in the liquid crystal display device 1, the image is enlarged, so that the bright spot is also enlarged and displayed on the screen. Therefore, by providing the light shielding means 9 in the area corresponding to the defective pixel area A1 and blocking incident light as in the present invention, it is possible to prevent the bright spot from being enlarged and displayed. As a result, the display quality of the image is significantly improved.

FIG. 3 is a plan view of the liquid crystal display device 1.
The light shielding means 9 is a square covering the pixel electrode 6a, as shown in FIG. The light shielding means 9 has a height of 150 μm.
m, 150 μm in width and 100 μm in depth. Also,
As shown in FIG. 3B, the shape may be a circle, or any other shape as long as the shape includes the pixel electrode 6a.

FIG. 4 is a process diagram for explaining a manufacturing process of the liquid crystal display device 1, and FIG. 5 is a sectional view for explaining a method for manufacturing the liquid crystal display device 1. In this embodiment, FIG.
The case where the light shielding means 9 is formed on the transparent substrate 2 side as shown in (1) will be described.

In step a1, as shown in FIG.
The covering member 16 is formed over substantially the entire surface of the transparent substrate 2. In this embodiment, the covering member 16 has a thickness of 50 μm.
A cellophane tape of about m is adhered to the surface of the transparent substrate 2 using an adhesive or the like.

In step a2, as shown in FIG.
By irradiating an excimer laser or the like,
To form The recess 17 has a length of 150 μm and a width of 1 μm, for example.
It is selected to be 50 μm and depth 100 μm.

In step a3, as shown in FIG.
For example, the ink 18 containing the ultraviolet curable resin is
Fill inside. Then, in step a4, as shown in FIG. 5 (5), the ink 18 overflowing onto the covering member 16 is wiped off. In step a5, the light shielding means 9 is formed by peeling off the covering member 16 and thereafter irradiating ultraviolet rays to solidify the ink 18.

As the material of the covering member 16, various adhesive tapes, photoresist materials, glass, metals and the like can be used, but it is necessary to select a material corresponding to the energy of the excimer laser for the workpiece.

FIG. 6 is a diagram for explaining another embodiment of the present invention. By adjusting the thickness of the covering member 16, the thickness of the ink 18 at the time of wiping the ink can be adjusted. Therefore, as shown in FIG.
The thickness of the transparent substrate 2 can be made uniform so as to be uniform with the surface of the transparent substrate 2, and by selecting the thickness of the covering member 16 relatively large, as shown in FIG.
It is also possible to form a shape that rises from the surface of the substrate.

FIGS. 7 and 8 are views for explaining a comparative example in the present invention. In FIG. 7, the ink 18 containing the ultraviolet curable resin is applied directly on the defective pixel area A1 of the transparent substrate 2. In the comparative example shown in FIG. 7, the light-shielding means 9 is easily peeled off by an external factor such as wiping off the surface of the transparent substrate 2 and the film thickness is determined by the surface tension of the ink 18. It is difficult, and it is also difficult to make the thickness of the entire film uniform.

In FIG. 8, a recess is formed directly on the transparent substrate 2 without forming the covering member 16, and the recess is filled with the ink 18 containing the ultraviolet curing resin. In the comparative example shown in FIG. 8, if the amount of ink to be filled is too small, FIG.
As shown in (1), since the ink cannot be sufficiently filled in the recess, it is necessary to fill the recess with a relatively large amount of ink. In this case, as shown in FIG. 8 (2), the ink 18 overflows from the recess and must be wiped. At this time, as shown in FIG. 8 (3), the ink 18 at the center of the recess is also wiped off at the same time. Therefore, as shown in FIG. It is very difficult to form the means 9, and a sufficient film thickness cannot be secured.

Since the size of the recess is determined according to the pixel of the liquid crystal display device, it is usually several tens μm to one hundred and several tens μm.
Chosen as a corner.

FIG. 9 is a side view of the recess forming apparatus 30 used for forming the recess 17. The laser beam 32 emitted from the laser oscillator 31 passes through a slit pattern 33 in which a pattern having a shape in which the outer size of the recess 17 formed on the defective pixel area A1 is enlarged is formed, and is reflected by an ultraviolet reflecting mirror. After that, the light is condensed on the defective pixel area A1 of the liquid crystal display device 1 mounted on the mounting table 36 via the lens 35 and irradiated.

The laser beam 32 has a slit pattern 3
3, the defective pixel area A
The position 1 is precisely irradiated. Although it is difficult to form the blocking piece 6 in a shape corresponding to the rectangular defective pixel area A1, the use of the slit pattern 33 allows the concave portion 17 to be formed in a rectangular shape, thereby reducing the formation area. be able to. Further, the mounting table 36 is movable in, for example, two XY orthogonal directions in a horizontal plane, and the movement of the mounting table 36 can irradiate the laser beam 32 to a desired defective pixel area A1.

FIG. 10 is a view showing a light shielding means installation device 20 used in the present invention, and FIG.
FIG. 10B is a view illustrating a step b1 of FIG. 1, and FIG. 10B is a view illustrating a step b5 of FIG.

A sliding member 41 that slides along the rail 40 is provided on the lower surface side of the rail 40 horizontally installed by the frame 49. The sliding range of the sliding member 41 on the rail 40 is defined by two stoppers 42a and 42b installed on the rail 40.

A support member 43 is installed on the sliding member 41 downward in FIG.
A sliding piece 44 is provided so as to be slidable in the up-down direction. A needle 45 is provided on the sliding piece 44 in a downward direction in FIG.

One end of a spring 46 is connected to the sliding member 41, and the other end of the spring 46 is connected to a sliding piece 44. The sliding piece 44 is biased by a spring 46 toward the sliding member 41.

A table 48 is provided below the structure shown in FIG. On the table 48, a container 47 containing the ink 18 serving as the light shielding means 9 and the liquid crystal display device 1 having the defective pixel area A1 are installed. The ink 18 contains an ultraviolet curable resin, and is a liquid before the ultraviolet irradiation treatment.

The container 47 is provided at a position where the sliding member 41 is brought into contact with the stopper 42a, the sliding piece 44 is lowered, and the ink 18 adheres to the needle 45. Further, the liquid crystal display element 1 is arranged such that the sliding member 41 is brought into contact with the stopper 42b, the sliding piece 44 is lowered, and the defective pixel area A1 is located at the position P where the needle 45 contacts.

FIG. 11 is a process diagram illustrating a process of installing the light shielding means 9 using the shielding piece installation device 20 shown in FIG. In step b1, as shown in FIG. 10A, the sliding member 41 is slid to a position where it contacts the stopper 42a. In this position, the needle 45 is located on the ink 18. In step b2, the ink is attached to the tip of the needle 45 by descending the sliding piece 44.

In step b3, the sliding member 41 is brought into contact with the stopper 42b, and the needle 45 is moved when the sliding piece 44 is lowered.
A defective pixel region A of the liquid crystal display device 1
The liquid crystal display device 1 is positioned so that 1 comes.

In step b4, the sliding member 41 is
2b until it comes into contact with it.
As shown in (2), the sliding piece 44 is lowered to bring the tip of the needle 45 into contact with the defective pixel area A1, and the ink 18 is attached.

Thereafter, the ink 18 is irradiated with ultraviolet rays to be cured. The ink 18 is cured and fixed on the liquid crystal display device 1.

The size of the light shielding means 9 to be formed is
Arbitrarily selected depending on the tip shape and thickness of the ink, the thickness of the ink 18 in the container 47, and the like.

As described above, according to the present embodiment, by blocking the optical path of the light passing through the defective pixel area A1,
Light leakage from defective pixels can be prevented, and display quality can be improved.

[0047]

As described above, according to the present invention, the light leaking from the area corresponding to the defective pixel is shielded by the light shielding means provided in the area corresponding to the defective pixel on the optical path of the incident light and the output light. Is done. Therefore, it is possible to prevent light from leaking from the region corresponding to the defective pixel, and it is possible to significantly improve display quality. According to the present invention,
For example, increase the thickness of the light-shielding resin formed in the recess
And a sufficient light-shielding property can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device 1 according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a usage example of the liquid crystal display device 1.

FIG. 3 is a plan view of the liquid crystal display device 1.

FIG. 4 is a process chart for explaining a method for manufacturing the liquid crystal display device 1.

FIG. 5 is a cross-sectional view for explaining the method for manufacturing the liquid crystal display device 1.

FIG. 6 is a diagram for explaining another embodiment of the present invention.

FIG. 7 is a diagram for explaining a comparative example in the present invention.

FIG. 8 is a diagram for explaining a comparative example in the present invention.

9 is a side view of the recess forming device 30. FIG.

FIG. 10 is a side view of the light shielding means installation device 20.

FIG. 11 is a process diagram illustrating a method of forming a light shielding unit.

[Description of Signs] 1 Liquid crystal display device 2, 3 Transparent substrate 4 Full surface electrode 5, 7 Alignment film 6 Pixel electrode 8 Liquid crystal layer 9 Light shielding means 16 Covering member 17 Depression A1 Defective pixel area

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuya Yoshimura 22-22 Nagaikecho, Abeno-ku, Osaka-shi Inside Sharpe Co., Ltd. (56) References JP-A-1-187532 (JP, A)

Claims (1)

(57) [Claims] A liquid crystal layer is interposed between a pair of translucent substrates,
A liquid crystal display device in which a plurality of pixels are formed in a matrix
In the manufacturing method, a liquid crystal of at least one of the pair of translucent substrates is used.
Forming a coating means on the surface opposite to the layer, on the optical path of the incident light and the emitted light, and
The area corresponding to defective pixels on the side of the plate where the coating means is formed
A liquid crystal display device , wherein a recess is formed in a region, a light shielding resin is filled in the recess, and the covering means is peeled off.
Manufacturing method.