JPH1031220A - Production of liquid crystal display device, and production device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain a uniform gap even when there are no spacers for gap control in display parts by applying different pressures on the sealing parts and display parts of glass substrates in a press bonding and curing stage of the glass substrates. SOLUTION: The press bonding and curing of the first glass substrate 1 coated with sealing materials 3 contg. the spacers 4 and the second glass substrate 2 which are stuck to each other in a previous stage. Flow passages 7 for compressed air A for sealing parts 13 and flow passages 8 for compressed air B for display parts 14 are separately formed at an upper plate 6 for pressurization of a pair of the set glass substrates 1, 2. The compressed air A does not directly pressurize the sealing parts 13 and an annular pressurizing member 11 pressurizes the annular sealing members 13. The compressed air B enters a pressurizing chamber 15 through the flow passages 8 and applies the pressure directly on the display parts 14 of the glass substrates. The uniform control of the gap is made possible by applying the pressure different from the pressure on the sealing parts 13 to the display parts 14 in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device having a liquid crystal layer sandwiched between two substrates and used in a projector, a viewfinder, and the like.

[0002]

2. Description of the Related Art A conventional method will be described with reference to FIG. The cushioning material 20 and the pair of glass substrates 1 and 2 to be pressed are sandwiched between the upper plate 19 which is a pressing material and the glass plate 5 until the gap between the pair of glass substrates 1 and 2 reaches a predetermined value. Then, a sufficient load is applied to the upper plate 19, and the sealing material 3 is cured when the gap is stabilized (hereinafter, a material obtained by pressing and compressing a pair of glass substrates is referred to as a liquid crystal cell).
The method of curing the sealing material 3 varies depending on the type of the adhesive of the sealing material 3, but as shown in FIG.
There is a case of irradiating V or a case of curing by heating. Regardless of the curing method, the cushioning material 20 is used to apply a load uniformly. As the cushioning material 20,
As shown in FIG. 5, there are a type that can load the entire surface as shown in FIG. As shown in FIG. 5, the cushioning material 20 is made of paper, rubber, sponge rubber, glass, or the like having a buffering property. In some cases. When a load is applied using this cushioning material 20, the sealing portion 1 containing the spacer 4 as shown in FIG.
Reference numeral 3 denotes a gap determined by the diameter of the spacer 4, and the display unit 14 without the spacer 4 for forming the gap.
Has a concave shape in which the center is the most concave. Here, the reason why the spacer 4 is not provided in the display unit is that the display quality is not deteriorated in applications such as a projector.

As another method, there is a method in which a load is applied only to the seal portion 13 in order to prevent the display portion 14 from becoming concave. In this case, by forming the cushioning material 20 into the cutout shape 23 as shown in FIG. 6, a load can be applied only to the seal portion 13 without applying a load to the display portion 14. Since the load is concentrated, the stress is concentrated at the center of the display unit 14 and the shape becomes a convex shape as shown in FIG.

As a measure for improving the above-mentioned conventional method, there is a method of heating the liquid crystal cell after press-bonding and curing, thereby relaxing the strain stress of the concave or convex liquid crystal cell to make the liquid crystal cell flatter.

Further, on the assumption that the liquid crystal cell has a concave or convex shape after pressure bonding and curing to some extent,
There is also a method of flattening in the sealing step. For example, as described in JP-A-6-75233, when the liquid crystal is sealed, the display section is forcibly flattened by using a suction pump and a pressure pump while measuring the gap at the center of the display section of the liquid crystal cell. In other words, there is a method of controlling and sealing so that the gap becomes a predetermined gap.

[0006]

However, the above prior art has the following problems.

[0007] In the conventional pressure bonding and curing using a cushioning material, there is a problem that the shape of the liquid crystal cell does not become flat but always becomes concave or convex. As a solution to this, relaxation of strain stress due to heat can be considered. However, in this method, there is a large variation in warpage of the glass substrate caused by a glass film forming process which is a preceding process, and a glass substrate of a sealing material which is softened by heat. However, there are many uncertain factors in the influence on the liquid crystal cell, and it is difficult to control the liquid crystal cell with high accuracy and to make the liquid crystal cell flat. Furthermore, as another solution, there is a method of flattening in the encapsulation / sealing process after pressing and curing.
The shape distortion of the unevenness of the liquid crystal cell formed at the time of curing cannot be absorbed because the sealing portion is cured, and the cross section after injection of the liquid crystal 24 has a wrinkled shape near the sealing portion as shown in FIG. And there was a problem that a uniform gap could not be obtained.

With such a solution, it is impossible to obtain a liquid crystal display device having no display unevenness, which is the most important in quality, that is, a uniform gap.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a manufacturing method and a manufacturing apparatus for manufacturing a flat liquid crystal cell in a compression / curing step.

[0010]

According to a method of manufacturing a liquid crystal display device of the present invention, a gap is controlled by mixing a spacer only in a sealing material forming a sealing portion of a pair of glass substrates, thereby controlling the gap. In a method for manufacturing a liquid crystal display device in which liquid crystal is injected and sealed between the pair of glass substrates, different pressures are applied to a display portion and a seal portion of the pair of glass substrates, and the pair of glass substrates are pressed.

Further, the manufacturing apparatus of the liquid crystal display device of the present invention controls a gap by mixing a spacer only in a sealing material forming a sealing portion of a pair of glass substrates, and controls a gap between the pair of glass substrates. In the manufacturing apparatus of the liquid crystal display device to be injected and sealed, a first gas flow path for pressurizing the display portion of the glass substrate, and a second flow passage for pressurizing the annular seal portion of the glass substrate. A gas flow path is separately provided, and the annular seal portion of the glass substrate is pressurized by an annular pressure member that slides by the pressure of the second gas flow.

Further, a manufacturing apparatus for a liquid crystal display device in which a gap is controlled by mixing a spacer only in a sealing material forming a sealing portion between a pair of glass substrates, and a liquid crystal is injected and sealed between the pair of glass substrates. A structure in which the pair of glass substrates is sandwiched between a pressurizing material and a cushioning material having a punched shape capable of pressurizing an upper portion of a seal of the glass substrate and an inner portion of the seal portion by a certain amount, and applying a pressure. It is characterized by having.

[0013]

According to the present invention, even if a spacer for controlling a gap is not provided in a display unit,
By applying a different pressure to the display than the seal,
A flat liquid crystal cell can be made by uniformly controlling the gap.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a sectional view of an apparatus for manufacturing a liquid crystal display device according to a first embodiment of the present invention. The present apparatus comprises a first glass substrate 1 having a sealing material 3 containing a spacer 4 applied thereto and a second glass substrate 2 bonded together in a previous step.
Then, the pair of glass substrates are pressed and cured. In this drawing, a case where a plurality of products are obtained from a pair of glass substrates is shown, but a single product may be used depending on the glass substrate and the product size.

First, the pair of glass substrates 1 and 2 are set on a glass plate 5. In order to press the pair of glass substrates 1 and 2 thus set, the upper plate 6 is provided with a sealing portion 13.
The flow path 7 for the compressed air A for use and the flow path 8 for the compressed air B for the display unit 14 are separately formed. The compressed air A is the seal part 1
Rather than directly pressurizing 3, the annular pressing member 11 presses the annular seal portion 13. The annular pressing member 11 can be slid with the annular pressing member guide 9 against the guide with compressed air. The annular pressing member 11 is
Thus, the compressed air does not leak, and uniform pressure of the compressed air can be transmitted. Furthermore, a uniform pressure can be applied to the annular pressing member 11 by attaching the buffer material 12 to a portion that comes into contact with the glass substrate. Cushioning material 1
Numeral 2 also serves to seal compressed air added to the display unit described later. The other compressed air B enters the pressurizing chamber 15 through the flow path 8 and directly applies pressure to the display unit 14 (inside the above-described annular pressurizing member 11) of the glass substrate. The compressed air B is a buffer material 1 attached to the annular pressure member 11 described above.
2, and the pressure can be uniformly applied to the display unit 14 of the glass substrate. By doing this,
Ideal uniform pressure can be applied to the seal portion 13 and the display portion 14 of the glass substrate. After the pressurization, the sealing portion 13 is hardened through the glass plate 5 with UV light from below to complete the liquid crystal cell.

Normally, the gap control of the display portion 14 of the glass substrate by the spacer 4 is performed by applying a uniform pressure to the entire surface of the glass substrate. However, in the present invention, the spacers 4 for gap control are not used in the display unit 14 in order to make display quality a problem, such as for a projector. In this case, as shown in the conventional example, in order to prevent the liquid crystal cell from having a concave shape under uniform pressure and a convex shape under the concentrated load of only the seal portion 13, the pressure between the seal portion 13 and the display portion 14 is separately set. In other words, by applying a certain force to the display unit 14 to reduce the stress concentration by applying a certain force to the display unit 14 due to the load of the seal unit 13,
The liquid crystal cell can be made flat.

(Embodiment 2) FIG. 2 is a sectional view of an apparatus for manufacturing a liquid crystal display device according to a second embodiment of the present invention. Also in this embodiment, the number of products taken from one glass substrate can be applied to both plural and single products. The present device is a method of applying a load using a rigid pressing member 16 and a cushioning material 17 without using compressed air, and by removing the cushioning material so that a certain amount of pressure is applied to the display portion of the glass substrate. is there. The buffer member 17 is used to apply a uniform pressure to the glass substrate, but is also used to select a pressurized portion. As the cushioning material 17, paper, rubber, rubber sponge, glass, or the like, which is a material having a cushioning property, is used.

In this case, a cushioning material 17 having a shape as shown in FIG. 3 is used so that pressure can be applied to the display section. FIG.
Is a seal portion 13 of one product area surrounded by a seal material.
2 shows a position 18 at which the cushioning material 17 is removed. The cushioning material 17 has a cutout shape that can be partially pressurized not only to the seal portion 13 of the glass substrate but also to the display portion inside the seal portion 13. The pressure applied to the glass display unit can be controlled by how much pressure is applied from the seal unit 13, that is, by inserting the buffer material 17 further inside. It is necessary to change how much pressure is applied depending on the area of the glass substrate surrounded by the seal, the aspect ratio of the seal pattern, the material and thickness of the glass substrate.
By using a cushioning material with such a shape, it is possible to change the pressure applied to the seal part of the glass substrate and the force applied to the display part, and evenly control the gap even for a pair of glass substrates without spacers in the display part Will be able to

The liquid crystal cell pressed and cured according to the embodiment shown in FIGS. 1 and 2 is completed as a liquid crystal display device through a subsequent sealing step. In the sealing step, the flat liquid crystal cell thus manufactured does not require any suction or pressurization for obtaining a uniform gap, and does not cause a problem such as distortion after sealing. This is because when the liquid crystal is injected into the liquid crystal cell, the liquid crystal cell tends to return to the shape of the liquid crystal cell formed in the pressure bonding step. The liquid crystal display device having a flat and uniform gap can be completed by leaving it for a certain period of time and sealing it when the liquid crystal has completely entered.

[0020]

As described above, according to the present invention, it is possible to apply different pressures to the sealing portion and the display portion of the glass substrate in the pressing and curing steps of the glass substrate, so that the gap is formed in the display portion. Even when there is no control spacer, a uniform gap can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a manufacturing apparatus showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a manufacturing apparatus showing a second embodiment of the present invention.

FIG. 3 is a plan view showing a position where a seal portion and a cushioning material are removed.

FIG. 4 is a cross-sectional view of a conventional device.

FIG. 5 is a perspective view showing a composite cushioning material.

FIG. 6 is a perspective view showing a punching cushioning material.

FIG. 7 is a cross-sectional view of the liquid crystal cell after pressure bonding and curing.

FIG. 8 is a cross-sectional view of the liquid crystal cell after pressure bonding and curing.

FIG. 9 is a cross-sectional view of a liquid crystal cell after liquid crystal injection.

[Explanation of symbols]

 Reference numerals 1 and 2 Glass substrate 3 Sealing material 4 Spacer 5 Glass plate 6 Upper plate 7, 8 Flow path 9 Annular pressure member guide 10 Packing 11 Annular pressure member 12 Buffer material 13 Seal part 14 Display part 15 Pressure chamber 16, 19 Upper plate 18 Drilled part 17, 20 Buffer material

Claims (3)

[Claims] 1. A method for manufacturing a liquid crystal display device, in which a gap is controlled by mixing a spacer only in a sealing material forming a sealing portion between a pair of glass substrates, and a liquid crystal is injected and sealed between the pair of glass substrates. 3. The method for manufacturing a liquid crystal display device according to claim 1, wherein different pressures are applied to the display portion and the seal portion of the pair of glass substrates to press the pair of glass substrates. 2. A manufacturing apparatus for a liquid crystal display device, wherein a gap is controlled by mixing a spacer only in a sealing material forming a sealing portion between a pair of glass substrates, and a liquid crystal is injected and sealed between the pair of glass substrates. In, a first gas flow path for pressurizing the display portion of the glass substrate, and a second gas flow path for pressurizing the annular seal portion of the glass substrate are separately provided, The annular seal of the glass substrate
An apparatus for manufacturing a liquid crystal display device, wherein pressure is applied by an annular pressing member that slides by the pressure of a second gas flow. 3. A manufacturing apparatus for a liquid crystal display device, in which a gap is controlled by mixing a spacer only in a sealing material forming a sealing portion of a pair of glass substrates, and a liquid crystal is injected and sealed between the pair of glass substrates. A structure in which the pair of glass substrates is sandwiched between a pressurizing material and a cushioning material having a punched shape capable of pressurizing an upper portion of a seal of the glass substrate and an inner portion of the seal portion by a certain amount, and applying a pressure. An apparatus for manufacturing a liquid crystal display device, comprising: