JPH10111497A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device in which a liquid crystal panel can be surely prevented from fracture even when a large shock is added due to falling or other cause to the liquid crystal display device. SOLUTION: This liquid crystal display device has a pair of glass substrates 2a, 2b facing each other through a liquid crystal 4. The side faces of the glass substrates 2a, 2b are heat-treated by irradiation of laser light. The side faces of the glass substrates may cause cracking in the production process of a liquid crystal panel, however, these cracks can be eliminated by dissolving a proper position in the side faces of the substrates by heat treatment. Therefore, fracture in the liquid crystal panel due to cracks can be prevented.

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 device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween, and a method of manufacturing the liquid crystal display device.

[0002]

2. Description of the Related Art In general, a liquid crystal panel, which is a main component of a liquid crystal display device, is often manufactured from a large glass substrate by a multi-piece method. For example, Japanese Unexamined Patent Publication No.
Japanese Patent Application Publication No. 157,642 discloses an example of a method for manufacturing such a liquid crystal panel. In this type of manufacturing method, first, a pair of glass substrates having a large area are overlapped and bonded to form a large glass substrate frame, and then a primary scribing process is performed using diamond or a super steel alloy. Cuts are made at appropriate places on both glass substrates, and the large-area glass substrate frame is divided into several intermediate glass substrate frames at the boundaries of the cuts. Then, a liquid crystal is injected into each of the plurality of liquid crystal panels included in the intermediate glass substrate frame, and each injection port is sealed. Thereafter, a secondary scribing process is performed on each of the intermediate glass substrate frames to make cutting scratches corresponding to the individual liquid crystal panels. Each liquid crystal panel is divided.

[0003]

However, in the above-mentioned conventional method for manufacturing a liquid crystal panel, when the glass substrate is cut from a cutting scratch formed by the primary scribe processing and the secondary scribe processing, the cutting is performed. In many cases, small chipping, that is, cracks occurred on the end surface of the glass substrate. If such cracks are formed on the end face of the substrate, there is a problem that when the liquid crystal panel is dropped, cracks are generated on the liquid crystal panel surface starting from the cracks and the liquid crystal panel is broken. In particular, when the liquid crystal panel is used as an information display section of a mobile phone, there is a high possibility that the liquid crystal panel will fall on the mobile phone and thus the liquid crystal panel will be broken by the drop.

It is not known whether the purpose is to prevent the liquid crystal panel from cracking.
No. 68 discloses a technique of protecting an outer edge portion of a liquid crystal panel and a circuit board and the like provided on the outer edge portion by covering them with a mold resin.

However, this publication does not specifically disclose how the mold resin is formed in relation to cracks generated on the end face of the liquid crystal substrate. Further, in FIG. 3 of the publication, the idea of forming a mold case at an appropriate interval at the outer edge of the liquid crystal panel is indicated, so that a crack existing on the end face of the liquid crystal substrate is broken. It can be easily understood that the mold resin is not formed for the purpose of preventing the development.

The present invention has been made in view of the above prior art, and even when a large shock is applied to the liquid crystal display device due to a fall or other causes, the liquid crystal panel in the liquid crystal display device is cracked. It is an object of the present invention to provide a liquid crystal display device capable of reliably preventing such a situation.

[0007]

In order to achieve the above object, a first liquid crystal display device according to the present invention is a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween. A heat treatment for melting the side end surface of the glass substrate is performed on the side end surface. Further, a first manufacturing method of the liquid crystal display device according to the present invention is a manufacturing method for manufacturing a liquid crystal display device having a pair of glass substrates opposed to each other with a liquid crystal interposed therebetween. A heat treatment step for dissolving the substrate end face. As the heat treatment here, for example, laser light irradiation can be considered.

According to the liquid crystal display device and the method of manufacturing the device, when a plurality of liquid crystal panels are indexed from a large glass substrate, cracks, that is, small chippings occur on the side end surfaces of the glass substrates of the individual liquid crystal panels. Even if this is done, by applying heat treatment to the side end surface of the glass substrate using laser light or the like, the end surface is melted and cracks are eliminated. As a result, it is possible to reliably prevent the liquid crystal panel from being cracked when a large impact is applied to the liquid crystal panel due to a drop or the like, which is caused by a defect serving as a crack starting point.

According to a second liquid crystal display device of the present invention, in a liquid crystal display device having a pair of glass substrates opposed to each other with a liquid crystal interposed therebetween, protection for covering cracks present on side end surfaces of the pair of glass substrates is provided. The member is provided on the side end surface. Further, a second manufacturing method of the liquid crystal display device according to the present invention is a manufacturing method for manufacturing a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween. And a protective member for covering a crack existing on the side end surface thereof is provided.

The protective member may be, for example, a molding resin applied to a region including a side end surface of the glass substrate. As the molding resin, for example, an epoxy resin which is a thermosetting resin, or an ultraviolet ray (U
V) An acrylic resin or the like, which is a curable resin, can be used. Further, a ceramic material can be used as the protective member.

According to the liquid crystal display device and the method of manufacturing the liquid crystal display device, even if cracks occur on the side end surfaces of the glass substrates of the individual liquid crystal panels when a plurality of liquid crystal panels are indexed from a large glass substrate, Since these cracks are filled with a protective member, for example, various resins or ceramic materials, even if the cracks are dropped, the cracks can be prevented from growing and developing into cracks.

It is desirable that the protective member is applied substantially only to the side end surface of the glass substrate and not applied to the information display surface of the glass substrate. This is because if the information display surface is provided, there is a disadvantage that the area of the information display surface is reduced. The term “substantially” includes a case where the protection member partially and slightly protrudes from the information display surface due to a work error or a property of the protection member.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a liquid crystal panel, which is a main component of the liquid crystal display device according to the first aspect of the present invention, and one main process in manufacturing the liquid crystal panel.
The liquid crystal panel 1 shown here has a pair of glass substrates 2a and 2b adhered to each other by a sealant 3. The liquid crystal 4 is sealed in a space formed between the two glass substrates 2a and 2b, that is, in a so-called cell gap. Transparent electrodes (not shown) having a stripe shape or an appropriate pattern are formed on the inner surfaces of the glass substrates 2a and 2b, that is, opposing surfaces, and an input terminal pattern 5 communicating with those electrodes is formed on the inner surface of one of the glass electrodes 2b ( (The upper surface in the figure).

The glass substrates 2a and 2 of the liquid crystal panel 1
b, a polarizing plate (not shown) is adhered to each outer surface, and heat seal or FPC (Fl
exiblePrinted Circuit) with adhesive, ACF (Anisotrop
ic Conductive Film: Anisotropic conductive film), connected to the input terminal pattern 5 by soldering, etc., and further, a backlight, a reflection plate, and other accessory parts are attached to one glass substrate to manufacture a liquid crystal display device. Is done.

The liquid crystal panel 1 is manufactured, for example, as shown in FIGS. That is, first, two glass substrates 2 c and 2 d having a large area are bonded to each other by the sealant 3. Then, a primary scribing process is performed using diamond or a super steel alloy, and the glass substrate 2c,
A primary cutting flaw 6a is formed in 2d. Then, the two glass substrates 2c and 2d are individually pressed with a predetermined pressure by the pressing element 7, and the respective glass substrates 2c and 2d are cut from the cutting scratches 6a. A plurality of (five in the case of this embodiment) intermediate glass substrate frames 2e including the liquid crystal panel 1 (five in the case of the embodiment) are manufactured.

Thereafter, the liquid crystal 4 is sealed in the cell gap G formed between the glass substrates 2c and 2d with respect to each of the produced intermediate glass substrate frames 2e. And then
A secondary scribing process is performed using diamond or a super-steel alloy, and a cutting flaw 6 is formed on each intermediate glass substrate frame 2e at a planned cutting position corresponding to the size of one liquid crystal panel.
is formed, and the glass substrates 2c and 2d are individually pressed by the pressing element 7 at a predetermined pressure to cut the intermediate glass substrate frame 2e from the scratches 6b to divide the liquid crystal panel 1 one by one. .

By the way, when the individual liquid crystal panels 1 are indexed from the large glass substrates 2c and 2d as described above, each cut surface of the glass substrates 2a and 2b of the liquid crystal panel 1, that is, each of the glass substrates 2a and 2b Cracks may occur on the side end surfaces. If such cracks occur on the side end surfaces of the glass substrates 2a and 2b of the liquid crystal panel 1, and if the cracks remain in the liquid crystal display device as a final product without being repaired, the cracks may be dropped on the liquid crystal display device. When a large impact is applied, the glass substrate may be cracked starting from the crack, making it impossible to use it as a liquid crystal display device.

With respect to the liquid crystal panel 1 of the present embodiment, in order to prevent the glass substrate from cracking due to the cracks existing on the glass end face, when a crack occurs on the glass substrate end face, as shown in FIG. After the panel 1 is indexed and before a polarizing plate (not shown) is mounted, a laser light R is irradiated from the laser irradiation system 8 to the cracked glass substrate end surface to melt the glass substrate end surface by heat generation. This eliminates cracks. This allows
A liquid crystal panel and a liquid crystal display device having high impact resistance can be manufactured.

The laser beam R may be uniformly applied to all the side end faces of the glass substrates 2a and 2b, or it may be considered that the laser beam R is likely to be impacted in view of the use form of the electronic equipment using the liquid crystal panel 1. Alternatively, the laser beam R may be applied only to the side end surface to be selected.

In this embodiment, the laser irradiation system 8 includes a laser oscillator 9 for generating laser light, a lens system 11 for expanding or reducing the cross-sectional diameter of the laser light as required, and a mirror 12 for reflecting the laser light. It is comprised including. Mirror 12
The laser light can be irradiated to any desired position on the glass substrates 2a and 2b by appropriately adjusting the angle of.
In some cases, by continuously rotating and scanning the mirror 12, the entire surface of the side end surfaces of the glass substrates 2a and 2b can be irradiated with laser light.

(Second Embodiment) In the embodiment described above, the individual liquid crystal panels 1 are separated from the large glass substrates 2c and 2d, and then the individual liquid crystal panels 1 are separated as shown in FIG. Then, the end faces were irradiated with laser light to eliminate the cracks. However, instead of such a method, in FIG. 3, after performing a primary scribing process, after producing some intermediate glass substrate frames 2e, a liquid crystal is injected into those glass substrate frames. Prior to this, the laser beam is applied to the section of each intermediate glass substrate frame 2e so that cracks generated in the section can be eliminated.

Then, after the laser processing, liquid crystal is injected into each intermediate glass substrate frame 2e, each injection port is sealed, and a secondary scribe processing is performed to finally obtain the individual liquid crystal panel 1e. After that, the laser beam is applied to the cross sections of the glass substrates 2a and 2b formed by the secondary scribing process, so that the cracks in the cross sections can be eliminated.

As described above, before the liquid crystal panels 1 are completely divided one by one, laser irradiation may be performed on the divided planes of the liquid crystal panels while some liquid crystal panels are still connected. , Work efficiency is improved.

(Third Embodiment) FIG. 4 shows a liquid crystal panel which is a main component of the liquid crystal display device according to the third aspect of the present invention, and one step in manufacturing the liquid crystal panel. The liquid crystal panel 1 shown in this figure is the same as the liquid crystal panel 1 shown in FIG. 1, and the description thereof will be omitted. As described with reference to FIG. 1, cracks may occur on the side end surfaces of the glass substrates 2a and 2b of the liquid crystal panel 1. In the present embodiment, in order to repair the crack, while squeezing out the molding resin J from the tube 13 containing the molding resin as a protective member, the tube 13 is moved along the glass substrates 2a and 2b as shown by the arrow A. The resin J is applied to the entire side end surfaces of the glass substrates 2a and 2b by the parallel movement.

If the molding resin J is a thermosetting resin, for example, an epoxy resin, the resin applied to the end face on the substrate side is cured by heating. Further, the molding resin J is made of ultraviolet rays (U
V) In the case of a curable resin such as an acrylic resin, after the application is completed, the applied resin is irradiated with ultraviolet rays to be cured. As shown in FIG. 5, the resin J is desirably applied to the entire side end surfaces of the glass substrates 2a and 2b except for the side end surfaces where the input terminal patterns 5 are formed. Glass substrates 2a and 2 at portions where input terminal pattern 5 is formed
Resin J may be applied to the side end surface of b. However, since the side end surface may be reinforced by connecting a heat seal or the like to this portion, the resin J may not be applied. In most cases, there is no problem in practical use. Further, as shown in FIG. 6, the molding resin J is preferably applied only to the end faces of the glass substrates 2a and 2b and does not protrude from the information display surface 14a or 14b of the glass substrate 2a or 2b. The information display area is narrowed if it protrudes, so that it is avoided so that the entire surface of the liquid crystal panel 1 can be effectively used.

(Other Embodiments) The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to those embodiments, but may fall within the technical scope described in the claims. Various modifications can be made.

For example, the liquid crystal panel to which the present invention can be applied is not limited to the liquid crystal panel having the structure shown in FIGS. 1 and 4, but may be applied to a liquid crystal panel having an arbitrary structure in which cracks may occur on the side end surface of the glass substrate. Applicable. Further, in FIG. 1, the laser irradiation system 8 can have any configuration other than that shown. Further, in the embodiment shown in FIG. 3, the case where 5 × 5 = 25 liquid crystal panels 1 are taken out from one large glass substrate 2c and 2d is taken as an example, but how many liquid crystal panels are taken out. This can be freely determined.

[0028]

According to the liquid crystal display device of the first aspect and the method of manufacturing the liquid crystal display device of the sixth aspect, cracks generated on the side end surface of the glass substrate can be eliminated.
As a result, it is possible to reliably prevent the liquid crystal panel from being broken due to a crack when the liquid crystal panel receives an impact in the related art.

According to the liquid crystal display device of the present invention, fine cracks and cracks having complicated shapes can be reliably eliminated by a simple operation.

The liquid crystal display device according to the third aspect and the seventh aspect.
According to the manufacturing method of the liquid crystal display device described above, the crack generated on the side end surface of the glass substrate is covered and reinforced by the protective member. It is possible to reliably prevent the liquid crystal panel from breaking.

According to the liquid crystal display device of the fourth aspect, the side end surface of the liquid crystal panel can be reliably reinforced and the information display surface of the liquid crystal panel can be effectively utilized.

According to the liquid crystal display device of the fifth aspect, the protection member can be formed by a simple and reliable method.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a liquid crystal panel which is a component of a liquid crystal display device according to the present invention, and one process of a manufacturing method for manufacturing the liquid crystal panel.

FIG. 2 is a cross-sectional view illustrating an example of a manufacturing method for manufacturing the liquid crystal panel illustrated in FIG.

FIG. 3 is a plan view showing a large glass substrate before being cut.

FIG. 4 is a perspective view showing one embodiment of a liquid crystal panel which is a component of the liquid crystal display device according to the present invention, and one step of a manufacturing method for manufacturing the liquid crystal panel.

FIG. 5 is a plan view of the liquid crystal panel of FIG.

FIG. 6 is a cross-sectional view showing a cross-sectional structure of the liquid crystal panel along line BB in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2a, 2b Glass substrate 2c, 2d Large glass substrate before cutting 2e Intermediate glass substrate frame formed by primary scribe processing 3 Sealant 4 Liquid crystal 5 Input terminal pattern 6 Cutting flaw 7 Presser 8 Laser irradiation System 9 Laser oscillator 11 Lens system 12 Mirror 13 Resin tube 14a, 14b Information display surface of liquid crystal panel

Claims (7)

[Claims] 1. A liquid crystal display device having a pair of glass substrates opposed to each other with a liquid crystal interposed therebetween, wherein the side end surfaces of the pair of glass substrates have been subjected to a heat treatment for melting the portions. Display device. 2. The liquid crystal display device according to claim 1, wherein
The liquid crystal display device, wherein the heat treatment is a process of irradiating a side surface of the pair of glass substrates with laser light. 3. A liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween, wherein a protection member for covering cracks present on the side end surfaces of the pair of glass substrates is provided on the side end surfaces. Characteristic liquid crystal display device. 4. The liquid crystal display device according to claim 3, wherein
A liquid crystal display device, wherein the protection member is provided substantially only on the side end surface of the glass substrate, and is not provided on the information display surface of the glass substrate. 5. The liquid crystal display device according to claim 3, wherein the protective member is a molding resin applied to a side end surface of a glass substrate. 6. A manufacturing method for manufacturing a liquid crystal display device having a pair of glass substrates opposed to each other with a liquid crystal interposed therebetween, comprising a substrate end surface heat treatment step for melting the side end surfaces of the pair of glass substrates. A method for manufacturing a liquid crystal display device, comprising: 7. A manufacturing method for manufacturing a liquid crystal display device having a pair of glass substrates facing each other with a liquid crystal interposed therebetween, wherein a protective member for covering cracks present on side end surfaces of the pair of glass substrates is provided. A liquid crystal display device comprising a substrate end face processing step for providing on a side end face.