JPH1152392A - Apparatus for production of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the apparatus for production of a liquid crystal display device capable of uniformly spraying spacer materials to one substrate constitut ing the liquid crystal display device. SOLUTION: This apparatus for producing the liquid crystal display device has a spacer spraying device for spraying the spacers to one of the substrates constituting the liquid crystal display device. The spacer spraying device has a spacer weighing section 1, a spraying gun section 2 and a tube. The spraying gun section 2 consists of divided structures and comprises a nozzle 21 and an intermediate section 22. Spacer through-holes respectively having the same diameter are formed within the tube, the intermediate section 22 and the nozzle 21. The tube, the intermediate part 22 and the nozzle 21 are so joined that the wall surfaces of the spacer through-holes of the connecting part of the tube and the intermediate part 22 and the connecting part of the intermediate part 22 and the nozzle 21 are made flush with each other. As a result, the spacers do not adhere any more to the wall surfaces of the spacer through-holes and the spraying of the spacers uniformly to the substrate is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a liquid crystal display device having a structure in which two substrates are bonded together with a gap material therebetween, and a liquid crystal composition is sealed in the gap between these substrates.
In particular, the present invention relates to a structure of a spray device for spraying a gap material on a substrate. I do.

[0002]

2. Description of the Related Art Liquid crystal display elements can be classified by operation mode into TN (Twisted Nematic) type and STN (Super Twisted).
Nematic) type, SBE (Super Twisted Birefrigence Fe)
ct) type, GH (Guest Host) type, DS (Dynamic Scatterin)
g) type, among which there are field effect type T
N-type, STN-type and SBE-type liquid crystal display elements are generally used.

[0003] These commonly used liquid crystal display elements are:
In each case, the display is performed based on the operation principle utilizing the optical rotation of the nematic liquid crystal due to the twisted alignment. For example, an SBE type liquid crystal display device is disclosed in Japanese Patent Laid-Open No. 60-107020.

A simple matrix type liquid crystal display device using such a nematic liquid crystal has a scanning electrode substrate in which a plurality of scanning electrodes are arranged in rows and an alignment film is formed so as to cover them, and a plurality of signal electrodes are provided. And a signal electrode substrate on which a light distribution film is formed so as to cover them. Bar-shaped or granular spacers are scattered on the surface of one of the alignment films of these two substrates. Then, after the spacers are scattered, the scanning electrode substrate and the signal electrode substrate are disposed to face each other, the periphery thereof is sealed, and the liquid crystal composition is sealed in a gap (cell gap) formed by the spacer.

[0005] The gap between two opposing substrates is 4-12.
It is about μm. In addition, as a material of a nematic liquid crystal used for the liquid crystal composition, a cyclohexane-based, ester-based, biphenyl-based, pyrimidine-based liquid crystal, or the like is used.

Further, a chiral agent is added to the liquid crystal composition, and the molecular axis of the liquid crystal molecules is 180 ° -270 ° between the upper and lower substrates.
The angle is set so as to be twisted to an angle of about ° (preferably about 270７０ in practical use). The surface of the alignment film is subjected to a rubbing alignment treatment or the like, and the alignment is set so that the molecular axis of the liquid crystal is aligned with the surface of the alignment film at an inclination (pretilt) of an angle larger than 5 °.

A liquid crystal display device using such a nematic crystal has extremely steep threshold characteristics and retardation characteristics. Therefore, even if a slight nonuniformity occurs in the cell gap, the threshold voltage and the threshold voltage in that portion are reduced. The lighting state becomes non-uniform as compared with others, and display unevenness occurs. Therefore, in order to suppress such display unevenness, it is necessary to distribute the spacers uniformly to make the cell gap uniform.

Further, in recent years, liquid crystal display devices for expressing delicate images such as gradation display and color display have been put into practical use, and uniform display characteristics are required. Therefore, it is necessary to distribute the spacers more evenly than before to make the cell gap uniform.

[0009]

By the way, a manufacturing apparatus for a liquid crystal display device is provided with a spacer dispersing device.
The spacer is scattered by the spacer scatterer. The spacer dispersing device is roughly divided into a spacer weighing unit that measures the amount of the spacer to be sprayed and pressure-feeds the spacer, and a spacer supply unit that applies a charge to the spacer that is pressure-fed from the spacer weighing unit and sprays the spacer toward the substrate. It consists of.

FIG. 4 is a diagram showing a sectional structure of the spacer supply section. As shown in the figure, the spacer supply unit is usually composed of a plurality of tubular parts, and the inner diameter of each part is not always the same. For this reason, a joint or a step is formed in the spacer conduction hole inside the component constituting the spacer supply unit, and the spacer may be deposited on this portion, and the deposited spacer may be dispersed in a lump. When such massive spacers are scattered on the substrate, the cell gap between the substrates becomes non-uniform, causing display unevenness and point defects.

The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid crystal display device capable of uniformly dispersing a gap material on at least one substrate constituting the liquid crystal display device. It is to provide a manufacturing apparatus.

[0012]

In order to solve the above-mentioned problems, the invention of claim 1 is directed to a first substrate on which first electrodes are arranged and a first substrate on which second electrodes are arranged. A gap material spraying device for spraying a gap material on at least one of the surfaces of the second substrate and the first and second substrates facing each other with the spread gap material interposed therebetween; In a device for manufacturing a liquid crystal display device by enclosing a liquid crystal composition in the gap formed by the gap material, the gap material spraying device, a spray amount measuring unit that measures the amount of the gap material to be sprayed,
A nozzle for spraying a gap material at a tip portion, and a gap material supply unit that supplies the gap material output from the spray amount measuring unit to the tip of the nozzle via a gap material conduction hole; The wall surface of the gap material conducting hole extending from the output end of the quantity measuring unit to the nozzle is flush with the nozzle.

According to a second aspect of the present invention, in the apparatus for manufacturing a liquid crystal display device according to the first aspect, the gap material supply section has a structure divided into at least two parts. Has the gap material passage holes, and joins each of the divided portions such that the wall surfaces of the gap material passage holes are flush with each other.

According to a third aspect of the present invention, in the apparatus for manufacturing a liquid crystal display device according to the second aspect, the gap material supply section has a tube connected to the spray amount measuring section, and the tube connected to one end. A spray gun for applying a charge to the gap material that has passed through the tube, wherein the tube and the spray gun have the gap material passage hole, and the spray gun has a nozzle at a tip end thereof. , And is divided into at least two parts. Each of these divided parts is joined so that the wall surfaces of the gap material passage holes are flush with each other.

According to a fourth aspect of the present invention, in the liquid crystal display device according to any one of the first to third aspects, the wall surface of the gap material passage hole from the output end of the spray amount measuring section to the tip of the nozzle is formed by a joint. It is covered with a cylindrical member formed integrally without any steps.

According to a fifth aspect of the present invention, in the liquid crystal display device according to any one of the first to fourth aspects, the spray amount measuring unit is configured to supply the gap material made of a compressed fluid having a predetermined density or more to the gap material supply unit. To supply.

The invention of claim 1 will be described with reference to FIGS. 1 and 2, for example. The "spreading device spraying device" is used for the spacer spraying device, the "spreading amount measuring unit" is used for the spacer weighing unit 1, and the "nozzle" is used. Corresponds to the nozzle 21, the “gap material supply unit” corresponds to the spraying gun unit 2 and the spacer transport tube 3, and the “gap material conduction hole” corresponds to the spacer conduction hole 4.

The invention of claim 3 will be described with reference to FIG. 1, for example. "Tube" corresponds to the spacer transport tube 3, and "spray gun unit" corresponds to the spray gun unit 2.

The invention according to claim 4 will be described with reference to, for example, FIG. 3. The “cylindrical member” corresponds to the tube 5.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a manufacturing apparatus of a liquid crystal display device to which the present invention is applied will be specifically described with reference to the drawings. Hereinafter, the structure of a spacer dispersing device that disperses spacers on the alignment film surface of at least one of the scan electrode substrate and the signal electrode substrate that constitutes a simple matrix type liquid crystal display device will be described.

FIG. 1 is a view showing a schematic structure of a spacer spraying apparatus. The illustrated spacer dispersing apparatus includes a spacer weighing unit 1 for measuring the amount of spacer to be sprayed at one time, a spray gun unit 2 for applying a charge to the spacer to spray the spacer, and a spacer weighing unit 1 to the spray gun unit 2. And a spacer transport tube 3 for pressure-feeding the spacer.

Compressed air is fed into the spacer weighing section 1, and the measured spacer is pressure-fed toward the spacer transport tube 3. The spray gun unit 2 applies a high voltage to the spacer to apply a charge to the spacer, and sprays the spacer using electrostatic force.

While the spacer transport tube 3 shown in FIG. 1 is formed integrally, the spray gun unit 2 has a divided structure, and a nozzle 21 for spraying the spacers,
The nozzle 21 and an intermediate portion 22 joined to the spacer transport tube 3 are configured. The connecting portion between the intermediate portion 22 and the spacer transport tube 3 and the connecting portion between the intermediate portion 22 and the nozzle 21 are fixed by screws or the like so that the spacer does not leak outside. Each of the spacer transport tube 3, the intermediate portion 22, and the nozzle 21 is a hollow cylindrical member, and a spacer conduction hole 4 through which the spacer passes is formed in the inside thereof.

FIG. 2 is a diagram showing a sectional structure of a connecting portion 23 between the spacer transport tube 3 and the intermediate portion 22 and a connecting portion 24 between the intermediate portion 22 and the nozzle 21. Since the cross-sectional structures of these two connection portions 22 and 23 are the same, only one cross-sectional structure is shown.

As shown in the figure, the connecting portions 22 and 23 at both ends of the intermediate portion 22 are flush with each other so that no step is formed. Note that the peripheral areas of the inner walls of the spacer transport tube 3, the intermediate portion 22, and the nozzle 21 do not necessarily have to be the same, as long as the surfaces of the connection portions 22, 23 match.

As described above, by aligning the surfaces at the connection portions 22 and 23 at both ends of the intermediate portion 22, the spacers do not adhere to the connection portions 22 and 23, and there is no danger of the spacers being clumped and scattered. . Therefore, the spacers can be uniformly spread on the scanning electrode substrate or the signal electrode substrate.

An experiment was conducted to compare the case where the wall surface of the spacer conduction hole 4 was flush with the wall as shown in FIG. 2 and the case where the wall surface of the spacer conduction hole 4 had a step as shown in FIG.
In the case of FIG. 2, the generation of spacer lumps could be suppressed by about 20 to 30%.

The type of spacer output from the spacer weighing unit 1 is not particularly limited.
A bead-like plastic spacer or a rod-like spacer is used. Alternatively, a compressed fluid having a predetermined density (for example, 3 kg / cm ² ) or more may be allowed to flow from the spacer weighing unit 1. According to an experiment, when such a compressed fluid is caused to flow to the spacer spraying device having the structure shown in the drawing. It has been found that the spacer mass can be suppressed by about 50 to 60%, and the spacers can be more evenly sprayed.

By the way, the structure shown in FIG. 2 only eliminates a step at a connection portion, but does not eliminate a seam. For this reason, there is a possibility that the spacer may adhere to the joint part to some extent. Therefore, the wall surface of the spacer conducting hole 4 in the spacer spraying device is connected to the integrally formed tube 5 as shown in FIG.
May be covered with. Thereby, not only the step at the connection portion but also the seam can be completely eliminated, and the spacer conduction hole 4
The spacers are no longer attached to the wall surfaces, and the ratio of dispersing the spacer blocks can be further reduced as compared with FIG.

In the above embodiment, an example of manufacturing a simple matrix type liquid crystal display device has been described. However, the present invention can be similarly applied to an active matrix type liquid crystal display device. In that case, the TFT (Thi
n Film Transistor) The spacers may be sprayed on the active substrate using the spacer spraying apparatus of FIG.

The present invention can apply various types of liquid crystal compositions to be injected between two substrates.
The present invention is particularly effective for a liquid crystal display device using a nematic liquid crystal having high voltage response and retardation characteristics, such as an N-type liquid crystal and a TN-type liquid crystal. In addition, the present invention can be applied to, for example, a GH type liquid crystal display device. Although the example in which the spray gun unit 2 has a divided structure is described with reference to FIG. 1, the spacer transport tube 3 and the spacer conduction hole 4 of the spray gun unit 2 may be integrated. As a result, steps and seams can be eliminated, and the nozzle 2
There is no possibility that the spacer lump is sprayed from the point (1).

[0032]

As described above in detail, according to the present invention, since the wall surface of the gap material conducting hole extending from the output end of the spray amount measuring section to the nozzle is flush, the gap is formed on the wall surface of the gap material conducting hole. The material no longer adheres, and the gap material can be evenly spread on the substrate. Therefore, the gap between the two substrates to be bonded can be made uniform, and a liquid crystal display device with high display quality without display unevenness can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic structure of a spacer spraying device.

FIG. 2 is a diagram showing a cross-sectional structure of a connection portion at both ends of an intermediate portion.

FIG. 3 is a diagram showing an example in which a wall surface of a spacer conduction hole is covered with a tube integrally formed.

FIG. 4 is a diagram illustrating a cross-sectional structure of a spacer supply unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spacer weighing part 2 Spray gun part 3 Spacer transfer tube 4 Spacer conduction hole 21 Nozzle 22 Intermediate part

Claims (5)

[Claims] 1. A gap material sprayer for spraying a gap material on at least one surface of a first substrate on which first electrodes are arranged and a second substrate on which second electrodes are arranged. A first device and a second device, each of which is provided with a device interposed therebetween.
In a device for manufacturing a liquid crystal display device by sealing a substrate facing each other and sealing a liquid crystal composition in a gap formed by the gap material, the gap material spraying device reduces the amount of the gap material to be sprayed. A spraying amount measuring unit for measuring, and a nozzle for spraying a gap material at a tip portion, and a gap material for supplying the gap material output from the spraying amount measuring unit to a tip of the nozzle via a gap material conduction hole; A liquid crystal display device manufacturing apparatus, comprising: a supply unit; and a wall surface of the gap material conduction hole extending from an output end of the spray amount measuring unit to the nozzle. 2. The gap material supply section has a structure divided into at least two sections. Each of the divided portions has the gap material passage hole, and the wall surface of the gap material passage hole is 2. The apparatus according to claim 1, wherein each of the divided portions is joined so as to be flush with each other. 3. The gap material supply section includes: a tube connected to the spray amount measuring section; and a spray gun section connected to one end of the tube and applying a charge to the gap material passing through the tube. The tube and the spray gun section have the gap material passage hole, and the spray gun section has a structure in which the tip is provided with the nozzle and is divided into at least two parts. 3. The apparatus according to claim 2, wherein each of the portions is joined such that a wall surface of the gap material passage hole is flush with each other. 4. 4. The wall surface of the gap material passage hole from the output end of the spray amount measuring section to the tip of the nozzle is covered with a tubular member integrally formed without seams or steps. An apparatus for manufacturing a liquid crystal display device according to any one of claims 1 to 3. 5. The liquid crystal display according to claim 1, wherein said spray amount metering section supplies said gap material comprising a compressed fluid having a predetermined density or more to said gap material supply section. Equipment manufacturing equipment.