JP3894660B2 - Method and apparatus for manufacturing liquid crystal display element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a liquid crystal display element using a technique of interposing and curing a photocurable material between a pair of substrates, and more particularly to improving light irradiation to the photocurable material. .
[0002]
[Prior art]
In general, the process of assembling an empty cell before liquid crystal injection of a liquid crystal display element is performed by applying a sealing material to one or both of a pair of substrates subjected to orientation treatment by printing, spraying in-plane spacers, and fixing if necessary. Then, the pair of substrates are positioned, overlapped and temporarily fixed, and pressed to fix both substrates. In this process, in addition to the sealing material that finally bonds both substrates, a photo-curing material is used as a spacer fixing material that fixes spacers between both substrates, and a temporary fixing material that temporarily fixes both substrates. Is done.
[0003]
Examples of such a photo-curable material include a resin that is mainly cured by ultraviolet rays, such as a material mainly composed of acrylic and methacrylic monomers, or a material composed of a photoreactive epoxy resin.
[0004]
By the way, in the empty cell assembly process before liquid crystal injection of the liquid crystal display element, for example, in a conventional apparatus using a photo-curable material as a sealing material, as shown in FIG. A pair of substrates 1A and 1B is sandwiched between a pair of platens 2A and 2B made of a material capable of transmitting ultraviolet rays, such as quartz or borosilicate glass, and a photo-curing resin previously applied between the substrates 1A and 1B. Is irradiated with light from the lamp 3 on which the reflecting mirror 4 is located on the back part above the platen 2A located at the upper part to cure the photocurable resin and bond the two substrates 1A and 1B. .
[0005]
[Problems to be solved by the invention]
However, as the platen 2A, 2B made of quartz or the like, a size suitable for the transparent substrates 1A, 1B and a thickness sufficient to withstand the pressure applied to the pressure plate 2A, 2B are required. Was expensive and the entire device was expensive. In addition, since the light from the lamp 3 passes through the platen 2A and reaches the photocurable material, it is attenuated as well as the film thickness of the photocurable material as the light absorbing layer is usually very small, such as several μm. Since the phenomenon that the light of the part simply passes through occurs, in order to cure the photocurable material to a level with sufficient reliability, it is necessary to irradiate light from the lamp 3 for a long time, and energy consumption However, there was also a problem that productivity was poor.
[0006]
For this reason, the manufacturing method and apparatus of the liquid crystal display element which used the photocurable material as a sealing material in the stage before liquid crystal injection | pouring are not used widely, and have reached now.
[0007]
An object of the present invention is to provide a method and an apparatus for manufacturing a liquid crystal display element that can overcome such problems in the conventional apparatus and improve productivity with a simple apparatus.
[0008]
[Means for Solving the Problems]
In order to overcome the above-described problems, the liquid crystal display element manufacturing method according to the first aspect of the present invention is characterized in that it is interposed between a pair of substrates, at least one of which is a transparent substrate, at a stage before liquid crystal injection. In the manufacturing method of the liquid crystal display element including the step of curing the photocurable material, light is incident from the end surface of the transparent substrate, the incident angle of the light is changed relative to the end surface of the transparent substrate, and the light is It is in the point which hardens the said photocurable material by advancing, making it totally reflect within a transparent substrate . And by employ | adopting such a structure, arrival of light to a photocurable material can be performed favorably and a photocurable material can be hardened rapidly.
[0009]
A feature of the method for producing a liquid crystal display element of the present invention according to claim 2 is that the incident angle of light from the end face of the transparent substrate is 50 degrees or less. By adopting such a configuration, light can reach the photocurable material particularly efficiently.
[0010]
According to a third aspect of the present invention, there is provided an apparatus for manufacturing a liquid crystal display element in which the incident angle of light is changed relative to the end face of the transparent substrate toward the photocurable material interposed between the two substrates. Thus, there is provided a light irradiation means for allowing light to enter from the end face of the transparent substrate so that the light travels while being totally reflected in the transparent substrate . And by adopting such a configuration, it is possible to satisfactorily reach the light curable material from the light irradiation means through the end surface of the transparent substrate, and to quickly cure the photocurable material. .
[0011]
According to a fourth aspect of the present invention, there is provided an apparatus for manufacturing a liquid crystal display element according to the present invention, wherein the light irradiation means includes a plurality of optical fibers connected so that light from the light source enters from the end face of the transparent substrate substrate. There is in point. And by employ | adopting such a structure, light can enter simultaneously from the wide range of the end surface of a transparent substrate with a some optical fiber, and it can harden | cure more rapidly.
[0012]
A feature of the apparatus for manufacturing a liquid crystal display element according to the fifth aspect of the present invention is that the angle of each of the optical fibers is variable relative to the end face of the transparent substrate. By employing such a configuration, by adjusting the angle with respect to the end face of the transparent substrate in consideration of the total reflection, further performs better the arrival of light to the curable material, the photocurable The material can be cured more rapidly.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a principle embodiment of an apparatus for manufacturing a liquid crystal display element according to the present invention. In this embodiment, the apparatus has a pair of substrates 11A and 11B for forming a liquid crystal display element. Yes. In the present invention, it is necessary that at least one of the pair of substrates 11A and 11B is a transparent substrate for the incidence of light from the substrate end face. 11B is described as a transparent substrate.
[0014]
Incidentally, before Symbol transparent substrate 11A, in order to cure the photocurable material light is incident from the end surface of the 11B, the curing wavelength of photocurable material, transparent substrates 11A, 11B of the transparent region and the later-described lamp, 13 It is necessary that the three principal wavelengths of the two coincide.
[0015]
For this reason, the transparent substrates 11A and 11B may be either normal glass substrates or plastic substrates. Among these, as the material of the glass substrate, soda lime, borosilicate glass, non-alkali glass, or the like is used. Moreover, as a material of the plastic substrate, polyethylene terephthalate, polycarbonate or the like is used.
[0016]
The pair of transparent substrates 11A and 11B are sandwiched between a pair of platens 12A and 12B formed of a highly rigid metal, and particularly at the outer peripheral portion between the transparent substrates 11A and 11B. A photocurable resin, which is a photocurable material, is applied in advance.
[0017]
This photocurable resin contains, as a main component, a material obtained by adding a photoinitiator and a sensitizer to acrylic, methacrylic monomers and / or oligomers which are mainly cured by ultraviolet rays. Depending on the type of photoinitiator or sensitizer, a visible light curable type that is cured by visible light can also be used. In addition, a photoinitiator such as a type that generates an acid when irradiated with light is also practical, and this type of photoinitiator can also be used.
[0018]
A pair of lamps 13 and 13 as light irradiation means for making light incident from the end face of the transparent substrate toward the photocurable resin interposed between the transparent substrates 11A and 11B are mutually connected to the transparent substrates 11A and 11B. Are arranged so as to face both end faces 14A, 14B: 15A, 15B located on the back. As the lamp 13, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like can be used.
[0019]
The wavelength for curing the photocurable resin by the lamp 13 needs to be in the high transmittance region of the transparent substrates 11A and 11B, but the glass substrate and the plastic substrate as the transparent substrates 11A and 11B are: It can transmit at 365 nm, which is the main wavelength of high-pressure mercury lamps and metal halide lamps, at a very high rate. In addition, the glass substrate and the plastic substrate do not have any problem because they transmit the main wavelength of the xenon lamp.
[0020]
In the present embodiment, the lamp 13 is described as being irradiated from the two directions of the transparent substrates 11A and 11B. However, the lamp 13 may be irradiated from the four directions of the transparent substrates 11A and 11B. It is also possible to irradiate from only one direction.
[0021]
Further, a spherical surface is provided on the back portion of each lamp 13 so that most of the light from each lamp 13 faces both end surfaces 14A, 14B: 15A, 15B located on the back portions of both transparent substrates 11A, 11B. The upper reflecting mirror 16 is disposed.
[0022]
Furthermore, it is desirable that the incident angle of light from the end surfaces of both the transparent substrates 11A and 11B is incident at an angle of 50 degrees or less in order to smooth the total reflection of light in the substrates 11A and 11B and reduce loss. Therefore, the positions and orientations of the lamps 13 and the reflecting mirror 16 are variable. Note that the positions and orientations of the platens 12A and 12B sandwiching both the transparent substrates 11A and 11B may be variable.
[0023]
Next, the operation of the liquid crystal display element manufacturing apparatus according to the present embodiment having the above-described configuration, that is, the liquid crystal display element manufacturing method of the present invention will be described.
[0024]
As shown in FIG. 1, a photocurable material (not shown) is interposed between a pair of transparent substrates 11A and 11B sandwiched between a pair of platens 12A and 12B.
[0025]
Therefore, the lamps 13 and the reflecting mirrors 16 are positioned at predetermined positions so that light enters from the end surfaces 14A, 14B: 15A, 15B of the transparent substrates 11A and / or 11B, and then both lamps 13 are turned on. When light having a wavelength capable of curing the photocurable material being used is irradiated, the light advances through each of the transparent substrates 11A and 11B while being totally reflected, and a photocurable material having a refractive index larger than the refractive index of air is applied. Light is absorbed by the resin without being totally reflected only at the site where it is present, and the light energy is used for curing the photocurable material with high efficiency. The total reflection is repeated in both the transparent substrates 11A and 11B until the light is attenuated, and the light energy is used effectively.
[0026]
As a result, according to the present embodiment, the photocurable material can be efficiently cured.
[0027]
Thus, according to the liquid crystal display element manufacturing apparatus of the present embodiment, productivity can be improved with a simple configuration.
[0028]
2 and 3 show another embodiment of the apparatus for manufacturing a liquid crystal display element according to the present invention, which further embodies the light irradiation means in the embodiment of FIG. Therefore, the light irradiation means will be described with reference to FIGS.
[0029]
The configuration in which the reflecting mirror 16 is arranged on the back of the lamp 13 is the same as that of the embodiment of FIG. 1 described above, but in this embodiment, one end face 15A, 15B of the transparent substrates 11A, 11B. Are connected between the transparent substrates 11A, 11B and the lamp 13 so as to face almost the entire area. Each optical fiber 18 is disposed so that its base end faces the lamp 13. Between the lamp 13 and the optical fiber 18, the light of the lamp 13 is transmitted to the base end of each optical fiber 18. A condensing lens 19 for converging is arranged. The rear end of each optical fiber 18 faces the vicinity of the end faces 15A and 15B of the transparent substrates 11A and 11B. The tip of each optical fiber 18 is movable in order to change the incident angle of light with respect to the transparent substrates 11A and 11B.
[0030]
According to the substrate bonding apparatus using the light irradiation means having such a configuration, the light of the lamp 13 is efficiently transmitted to the end faces 15A and 15B of the transparent substrates 11A and 11B by the plurality of optical fibers 18 to be photocured. The material can be cured more efficiently.
[0031]
Next, specific examples of the method and apparatus for manufacturing a liquid crystal display element according to the present invention will be described.
[0032]
【Example】
Example 1
A silica film and an ITO film were formed by sputtering on a soda-lime transparent substrate (300 mm × 260 mm, 0.7 mm thickness), and then patterned by a photolithographic technique to form a transparent electrode. Next, the middle coat and the polyimide alignment film were sequentially printed and then fired. Subsequently, an ultraviolet curable sealing agent was printed UR-8000 a (Nagase Ciba), and the temporarily fixed superposed, sandwiched crimping machine with an optical fiber, the pressure of both platens of the crimping machine 0 while pressed at .5kg / cm ^2, the transparent substrate with light of a high pressure mercury lamp is condensed on the end face of the optical fiber tip serving measure and at the outlet integrated quantity of light 1000 mJ / cm ² of about 1/8 of the conventional method Irradiated light.
[0033]
After the assembled substrate was divided into panels, liquid crystal was injected by a vacuum injection method and heated at 110 ° C. for 30 minutes.
[0034]
When a reliability test was performed after the polarizing plate was attached, no defective display mode was found even after 500 hours had passed under high temperature and high humidity conditions of 90% RH at 60 ° C.
[0035]
In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.
[0036]
【The invention's effect】
As described above, according to the method and apparatus for manufacturing a liquid crystal display element of the present invention, productivity can be improved with a simple apparatus.
[0037]
That is, the method for manufacturing a liquid crystal display element of the present invention according to claim 1 includes a step of curing a photocurable material interposed between a pair of substrates, at least one of which is a transparent substrate . In the manufacturing method, light is incident from an end surface of the transparent substrate, the incident angle of the light is changed relative to the end surface of the transparent substrate, and the light curing proceeds by totally reflecting the light within the transparent substrate. Since the curable material is cured, the light can be satisfactorily reached to the photocurable material, and the photocurable material can be cured quickly, contributing to energy saving and improving the productivity.
[0038]
In the method of manufacturing a liquid crystal display element according to the second aspect of the present invention, since the incident angle of light from the end face of the transparent substrate is 50 degrees or less, the arrival of light to the photocurable material is particularly efficiently performed. Can be kept low. .
[0039]
According to a third aspect of the present invention, there is provided an apparatus for manufacturing a liquid crystal display element according to the present invention, wherein the light incident angle is changed relative to the end face of the transparent substrate toward the photocurable material interposed between the two substrates. Is provided with a light irradiating means for allowing light to enter from the end face of the transparent substrate so as to proceed while being totally reflected in the transparent substrate. It is possible to cure the photo-curing material quickly, contribute to energy saving, improve productivity, and it is not necessary to use an expensive UV-transmissive platen, and is inexpensive. A simple metal platen can be used, and the device can be manufactured at low cost.
[0040]
In the apparatus for manufacturing a liquid crystal display element according to the fourth aspect of the present invention, the light irradiating means has a plurality of optical fibers connected so that light from the light source enters from the end face of the transparent substrate substrate. Further, light can be simultaneously incident from a wide range of the end face of the transparent substrate by a plurality of optical fibers, and can be further rapidly cured.
[0041]
Apparatus for manufacturing a liquid crystal display device of the present invention according to claim 5, each optical fiber, since it is variable relatively angles to the end face of the transparent substrate, the end face of the transparent substrate in consideration of the total reflection By adjusting the angle with respect to the light curable material, it is possible to achieve better light arrival at the photocurable material, and to cure the photocurable material more rapidly, and to reduce energy loss.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating a first embodiment of a liquid crystal display element manufacturing apparatus according to the present invention. FIG. 2 is a front view illustrating a second embodiment of a liquid crystal display element manufacturing apparatus according to the present invention. 2 is a plan view of FIG. 2. FIG. 4 is a schematic diagram showing a conventional apparatus for manufacturing a liquid crystal display element.
1A, 11B Transparent substrates 12A, 12B Platen 13 Lamps 14A, 14B, 15A, 15B End face 16 Reflector 18 Optical fiber

Claims (5)

The manufacturing method of the liquid crystal display device having a step of curing the photocurable material in which at least one liquid crystal before injection stage is interposed between the substrates of the pair is a transparent substrate, from the end face of the front KiToru Akira substrate The light curable material is cured by causing light to enter, changing the incident angle of the light relative to the end surface of the transparent substrate, and proceeding while totally reflecting the light within the transparent substrate. A method for manufacturing a liquid crystal display element.   2. The method for manufacturing a liquid crystal display element according to claim 1, wherein an incident angle of light from an end face of the transparent substrate is 50 degrees or less. In a liquid crystal display device manufacturing apparatus having a light irradiation means for curing a photocurable material interposed between a pair of substrates, at least one of which is a transparent substrate at a stage before liquid crystal injection, the light irradiation means A light incident angle is changed relative to the end surface of the transparent substrate toward the photocurable material so that the light travels while totally reflecting inside the transparent substrate, and light is incident from the end surface of the transparent substrate. An apparatus for manufacturing a liquid crystal display element.   The said light irradiation means has the some optical fiber connected so that the light from a light source may inject from the end surface of a transparent substrate board | substrate, The manufacture of the liquid crystal display element of Claim 3 characterized by the above-mentioned. apparatus.   The apparatus for manufacturing a liquid crystal display element according to claim 4, wherein each of the optical fibers has a variable angle relative to an end surface of the transparent substrate.

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