JPH08328020A - Production of liquid crystal display element and device therefor - Google Patents

Abstract

PURPOSE: To produce a high definition liquid crystal display element. CONSTITUTION: An insulating layer 12 on a substrate 1 preliminarily rubbed is positively charged and inner electrodes 24 are grounded. When a positively charged gap forming agent 20 is sprayed through a nozzle 40 to the substrate 1 in a charged state, the gap forming agent 20 is recoiled by an electrostatic force from a pixel area 32 and is deposited only in a light-shielding area 34 having a low potential. Further, the gap forming agent 20 stuck on the light- shielding area 34 is fixed to form a spacer which maintains the thickness of a liquid crystal to be supplied in the pixel area 32.

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 element manufacturing method and apparatus for manufacturing a liquid crystal display element having an internal electrode for wiring in a light shielding region of a dielectric substrate.

[0002]

2. Description of the Related Art Image projectors (projectors) that display an image on a predetermined display device, pass a projection light beam, and project it on a screen or the like are widely used. A liquid crystal display element is often used in the display device of such a projector. In general, a liquid crystal display element is manufactured by laminating two substrates with a gap of several μm therebetween and filling the gap with liquid crystal. The distance between the two substrates needs to be adjusted according to the material of the liquid crystal. To meet this need, for example, Japanese Patent Laid-Open No. 63-287824 has been used.
Japanese Patent Laid-Open No. 63-285517 or Japanese Patent Laid-Open No. 2-110432 discloses a method of using a granular dielectric material (gap agent) as a spacer between two substrates.

[0003]

However, according to the method disclosed in Japanese Unexamined Patent Publication No. 63-287824, the liquid crystal exists in addition to the light-shielding region (black matrix) of the substrate on which the TFT and the like are arranged. Since the gap agent is also dispersed and fixed in the pixel area, the portion of the pixel area to which the gap agent adheres is in a state where the projection light beam always passes through or a state where the projection light ray is always blocked. . Therefore, when the entire projected screen is whitish, the part that is in the state of blocking the projection light always stands out as white dots (bright spots). On the contrary, when the entire projected screen is blackish, it always appears. The part that is in the state of allowing the projection light beam to pass through becomes noticeable as a black dot (dark spot).
This problem cannot be completely solved even by the method disclosed in JP-A-63-285517.

Further, according to the method disclosed in the above-mentioned Japanese Patent Laid-Open No. 2-110432, the substrate on which the TFTs and the like are arranged can be rubbed only after the gap agent is fixed. In the conventional low-definition liquid crystal display element, even if the vicinity of the boundary of the gap agent cannot be rubbed, the alignment state of the liquid crystal is not significantly affected. However, the direction of the rubbing treatment for the high-definition liquid crystal display element that is widely used at present is 45 °, and when the rubbing treatment is performed in this direction, the fixed gap agent has a large influence on the alignment state of the liquid crystal. It will have a significant impact on the quality of the projected image.

The present invention has been made in view of the above-mentioned problems of the prior art, and the gap agent can be fixed only in the light-shielding region of the substrate on which the TFT and the like are arranged, and the gap agent is not formed in the pixel region. It is an object of the present invention to provide a liquid crystal display element manufacturing method and a device thereof that are not fixed. Another object of the present invention is to provide a liquid crystal display element manufacturing method and apparatus capable of improving the quality of a projected image by eliminating the gap agent fixed in the pixel area.

Further, according to the present invention, the substrate on which the TFTs and the like are arranged can be rubbed before the gap agent is fixed, and the influence on the alignment state of the liquid crystal of the high-definition liquid crystal display element can be minimized. It is an object of the present invention to provide a liquid crystal display element manufacturing method and an apparatus therefor capable of obtaining a high quality image.

[0007]

In order to achieve the above object, a method of manufacturing a liquid crystal display device according to the present invention comprises a potential difference between a light shielding region of a dielectric substrate of the liquid crystal display device and a region other than the light shielding region. A granular dielectric of a predetermined size is charged and scattered so as to gather in the light-shielding region, and the granular dielectric is attached to the surface of the light-shielding region, depending on the thickness of the liquid crystal of the liquid crystal display element. Forming spacers.

Preferably, an internal electrode insulated from the surface of the dielectric substrate is arranged in the light-shielding region of the dielectric substrate, and the internal electrode is charged by charging the dielectric substrate to a predetermined polarity. Grounded, a potential difference is applied between the light-shielded region of the dielectric substrate and a region other than the light-shielded region, and a granular dielectric of a predetermined size is charged to the predetermined polarity and dispersed on the surface of the dielectric substrate. Then, the granular dielectric adhered to the light shielding region of the dielectric substrate is fixed, and the spacer is formed.

The liquid crystal display element manufacturing apparatus according to the present invention is an apparatus for manufacturing a liquid crystal display element having an internal electrode insulated from the surface of the dielectric substrate in a light-shielding region of the dielectric substrate. Dielectric substrate charging means for charging the dielectric substrate to a predetermined polarity, grounding means for grounding the internal electrode, and granular dielectric material of a predetermined size to the predetermined polarity to charge the surface of the dielectric substrate. And a granular dielectric fixing means for fixing the granular dielectric adhered to the light shielding area of the dielectric substrate.

[0010]

The liquid crystal display device manufacturing method according to the present invention includes a TFT.
A method of fixing a gap agent only to a light-shielding area of a liquid crystal display element provided with an internal electrode for wiring which is insulated from the surface in a light-shielding area of a dielectric substrate where Is charged and charged, and the internal electrode is grounded to provide a potential difference between the light-shielding region of the dielectric substrate and the pixel region.

Granular dielectric material (gap agent) having a predetermined size
Is charged to the same polarity as the dielectric substrate and sprayed on the surface of the dielectric, repels the gap agent that has fallen to the pixel area that is charged to the same polarity as the gap agent, and collects the gap agent in the light-shielded area that is almost at ground potential. To attach. Further, the gap agent gathered in the light-shielding area is fixed to form a spacer that makes the liquid crystal of the liquid crystal display element have a predetermined thickness.

[0012]

Embodiments of the present invention will be described below. Figure 1
It is a top view of the liquid crystal display element after each process of the liquid crystal display element manufacturing method which concerns on this invention is completed. As shown in Figure 1,
After each step (FIGS. 2 and 3) of the method for manufacturing a liquid crystal display element of the present invention is completed, the gap agent 20 is attached onto the internal electrodes 24 arranged inside the substrate 1 to form the light shielding regions 34, respectively. A pixel region 32 filled with liquid crystal is provided between the light shielding regions 34.

Hereinafter, a method of manufacturing a liquid crystal display device according to the present invention will be described with reference to FIGS. 2 and 3. FIG. 2 is a diagram showing a liquid crystal display device manufacturing method according to the present invention, in which (A)
Shows a cross section of the substrate 1 after the rubbing treatment, (B) shows a step (first step) in which the substrate 1 is positively charged and the internal electrode 24 is grounded to give a potential difference, and (C) is positively charged. The process (2nd process) of spraying the made gap agent 20 is shown,
(D) shows a step (third step) of attaching the gap agent 20 to the light shielding region 34 of the substrate 1. FIG. 3 shows the substrate 1 after the step of fixing the attached gap agent 20 (fourth step) is completed.
The cross section of is shown. Note that FIG. 3 corresponds to a cross-sectional view taken along the XZ plane of the substrate 1 after each step shown in FIG.

As shown in FIG. 2A, the substrate 1 comprises a transparent glass substrate 10 and a thin film transistor layer (TFT layer) 1.
4 is provided, the internal electrode 24 is provided in a portion which becomes the light shielding region 34 on the TFT layer 14, and the insulating layer 12 is provided with a predetermined transparent dielectric. The insulating layer 12 of the substrate 1 has the first to fourth steps of the method for manufacturing a liquid crystal display element according to the present invention shown in FIGS. 2 (B) to (D) and FIG.
Before entering the process, the direction indicated by the arrow in FIG. 1, that is, X,
A rubbing process is performed in the direction of 45 ° with respect to the Y axis in advance.

In the first step shown in FIG. 2B, a positive charge is applied to the insulating layer 12 of the substrate 1 and the internal electrode 24 is grounded. The potential of the portion of the surface of the insulating layer 12 above the internal electrode 24, that is, the region serving as the light-shielding region 34, is almost grounded because the added charge cancels the potential due to the negative charge generated in the internal electrode 24. It becomes an electric potential and the insulating layer 1
The electric potential of the other region of 2, that is, the region which becomes the pixel region 32 is a positive electric potential.

In the second step shown in FIG. 2C, a diameter corresponding to the type of liquid crystal display element to be manufactured, for example, TN.
When manufacturing a (Twisted Nematic) cell, 4 μm to 6 μm, or when manufacturing an FLC (ferroelectric liquid crystal) cell, a granular plastic (plastic ball) having a diameter of 2 μm or less is used. The gap agent 20 is sprayed so as to be atomized from the nozzle 40 to which the positive voltage V _H is applied. In this way, the nozzle 4 to which the positive voltage V _H is applied
By spraying the gap agent 20 from 0, the gap agent 20 can be charged with a positive charge and can be sprayed on the substrate 1.

In the third step shown in FIG. 2D, the gap agent 20 scattered on the light-shielding area 34 having a low potential gathers, and the gap agent 20 scattered on the pixel area 32 having a high potential is repelled by electrostatic force. Be done. As a result, the gap agent 20 adheres only to the light shielding area 34. In the fourth step shown in FIG. 3, the gap agent 20 attached to the light-shielding region 34 is fixed, sandwiched between the upper substrate (not shown) and the substrate 1 which are further overlaid on the light-shielding region 34, and then the pixel region 32 is formed. Spacers are formed to keep the filled liquid crystal (not shown) at the proper thickness as described above. After the fourth step is completed, the substrate 1 is filled with the liquid crystal in the pixel region 32 as in a general liquid crystal display element, and the upper substrate is stacked and fixed.

It should be noted that the gap agent 20 may be previously coated with an ultraviolet curable adhesive or the like, and the gap agent 20 may be fixed by spraying the gap agent 20 and then irradiating it with ultraviolet rays to cure it. Like the substrate 1, the light-shielding region 34 is not provided on the upper substrate but on the substrate 1 side where the TFT layer 14 is provided.
When forming the, it is possible to use a transparent upper substrate. Therefore, by using the UV curable adhesive, the gap agent 20 can be fixed before stacking the upper substrate, or the gap agent 20 can be fixed by stacking the upper substrate on the substrate 1 and irradiating ultraviolet rays collectively. Bonding of the upper substrate can be performed at one time.

A thermosetting adhesive may be applied to the gap agent 20 in advance. Even if a thermosetting adhesive is used, the gap agent 20 can be fixed before the upper substrates are stacked, as in the case of using the ultraviolet curable adhesive. It is also possible to do it every time. In addition, when the thermosetting adhesive is used, unlike the case where the ultraviolet curing adhesive is used, the same effect can be obtained even when the upper substrate is not transparent.

The diameter of the gap agent 20 is not limited to the above-mentioned two types, and any diameter can be used according to the thickness of the liquid crystal, so that the gap control of the liquid crystal display element can be easily performed. be able to. Also, the gap agent 2
The material of 0 is not limited to plastic, and may be, for example, a granular dielectric material such as silica.

Further, in the embodiment, the gap agent 20 is used.
Although the case where both of the insulating layer 12 and the insulating layer 12 are positively charged has been described as an example, the gap agent 2 for negatively charging them
0 is positively charged and a negative voltage is applied to the internal electrode 24,
Alternatively, the gap agent 20 is negatively charged and the internal electrode 2
A method such as applying a positive voltage to 4 may be adopted. Also,
Each step or all steps of the liquid crystal display element manufacturing method according to the present invention may be automatically performed by using a predetermined device. Further, although the liquid crystal display element using the TFT has been described in the embodiment, the liquid crystal display element manufacturing method and the apparatus thereof according to the present invention can be applied to other types of liquid crystal display elements. In addition to the examples described above, the liquid crystal display element manufacturing method and the method thereof according to the present invention can have various configurations, for example, as in the modified example shown here.

[0022]

As described above, according to the liquid crystal display element manufacturing method and apparatus according to the present invention, the gap agent can be fixed only in the light-shielding area of the substrate on which the TFT and the like are arranged, and the pixel area can be fixed. The gap agent is not fixed to the. Further, according to the liquid crystal display element manufacturing method and the apparatus therefor of the present invention, since the gap agent fixed in the pixel region is eliminated, bright spots and dark spots do not occur in the projected image,
The image quality can be improved. Further, according to the method for manufacturing a liquid crystal display element and the apparatus therefor according to the present invention, it is possible to perform a rubbing treatment on a substrate on which TFTs and the like are arranged before fixing the gap agent. Therefore, even when manufacturing a high-definition liquid crystal display element, the influence on the alignment state of the liquid crystal can be minimized, and a high-quality image can be obtained.

[Brief description of drawings]

FIG. 1 is a top view of a liquid crystal display element after each step of a method for manufacturing a liquid crystal display element according to the present invention is completed.

FIG. 2 is a diagram showing a method for manufacturing a liquid crystal display element according to the present invention, wherein (A) shows a cross section of a substrate after a rubbing treatment,
(B) shows the process of positively charging the substrate and grounding the internal electrodes to give a potential difference, (C) shows the process of spraying the positively charged gap agent, and (D) shows the substrate with the gap agent. The process of adhering to the light-shielding area of is shown.

FIG. 3 is a diagram showing a cross section of the substrate after the step of fixing the attached gap agent is completed.

[Explanation of symbols]

1 ... Substrate, 10 ... Glass substrate, 12 ... Insulating layer, 14 ... T
FT layer, 20 ... Gap agent, 24 ... Internal electrode, 32 ... Pixel region, 34 ... Shading region, 40 ... Nozzle

Claims (3)

[Claims] 1. A potential difference is applied between a light-shielding region of a dielectric substrate of a liquid crystal display device and a region other than the light-shielding region, and granular dielectrics of a predetermined size are charged so as to gather in the light-shielding region. A method for manufacturing a liquid crystal display element, comprising: spraying, adhering the granular dielectric to the surface of the light shielding area, and forming spacers corresponding to the thickness of the liquid crystal of the liquid crystal display element. 2. An internal electrode insulated from the surface of the dielectric substrate is disposed in the light-shielding region of the dielectric substrate, and the dielectric substrate is electrically charged to a predetermined polarity to ground the internal electrode. A potential difference is provided between a light-shielding region of the dielectric substrate and a region other than the light-shielding region, and a granular dielectric of a predetermined size is charged to the predetermined polarity and dispersed on the surface of the dielectric substrate, The method for manufacturing a liquid crystal display element according to claim 1, wherein the spacer is formed by fixing the granular dielectric adhered to a light-shielding region of the dielectric substrate. 3. An apparatus for manufacturing a liquid crystal display device having an internal electrode insulated from the surface of the dielectric substrate in a light-shielding region of the dielectric substrate, the dielectric substrate charging the dielectric substrate to a predetermined polarity. Body substrate charging means, grounding means for grounding the internal electrode, charging means for charging a predetermined size of a granular dielectric material to the predetermined polarity and spraying it on the surface of the dielectric substrate, and the dielectric material. An apparatus for manufacturing a liquid crystal display device, comprising: a granular dielectric fixing means for fixing the granular dielectric adhered to a light shielding area of a substrate.