JP2001066575A - Method for joining dustproof glass of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to suppress the generation of air bubbles in adhesives and to suppress the flooding of the adhesives by resting the adhesives for a specified time at ordinary temperature to cure the adhesives. SOLUTION: The second adhesive 32 is arranged to an approximately dome shape on a color filter surface 20A of an LCD panel 20 and dustproof glass 30A is arranged at a prescribed angle of inclination with a color filter surface 20A. The first side 301 of the dustproof glass 30A is turned and displaced so as to gradually approach the LCD panel 20 side and while the second adhesive 32 is crushed to a thin film form, the dustproof glass 30A and the LCD panel 20 are arranged in tight contact with each other through the thin film-like second adhesive 32. The dusproof glass on a TFT surface 20B side of the LCD panel 20 is adhered by the similar procedures. The joined body formed by adhering an outer frame, the LCD panel 20, the dusproof glass 30A, etc., is rested for the specified time (for example, 24 hours) at ordinary temperature (for example, 23 to 27 deg.C) in order to solidify the second adhesive 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding a dustproof glass of a liquid crystal display device in which an LCD panel is bonded and fixed in an outer frame, and dustproof glass is bonded and fixed to both sides of the LCD panel.

[0002]

2. Description of the Related Art Conventionally, an LCD panel, dust-proof glass, and the like are provided in an outer frame attached to an apparatus body provided with a light source and the like.
And a liquid crystal display device having a structure in which a parting plate and the like are mounted. This liquid crystal display device transmits light from the light source to L
The light is incident on a CD panel, and the incident light passes through a color filter, is modulated by driving liquid crystal, and is emitted.
After an LCD panel to which a color filter has been mounted is bonded and fixed in an outer frame, dustproof glass is bonded and fixed to both sides of the LCD panel, and a parting plate is mounted on both sides of the outer frame.

[0003] In the process of manufacturing such a conventional liquid crystal display device, when a dustproof glass is bonded and fixed to both sides of the LCD panel bonded and fixed in the outer frame, a thermosetting adhesive is used. The combined body of the outer frame, the LCD panel, and the dust-proof glass is heated to, for example, 30 ° C. to 40 ° C. to be solidified. Further, in the conventional manufacturing process of the liquid crystal display device, in order to remove bubbles in the adhesive layer generated when the dustproof glass is bonded to the LCD panel,
The defoaming process by pressurization was performed by a pressurizing device.

[0004]

However, in the manufacturing process of the above-mentioned conventional liquid crystal display device, after adhering the dustproof glass to the LCD panel and then solidifying the thermosetting adhesive, it is required to be 30 ° C. to 40 ° C. C, so that the outer frame and the LCD panel (color filter and TF
Due to the difference in the coefficient of thermal expansion of the dust-proof glass and the stress caused by the hardening of the adhesive in a short time, each part of the liquid crystal display device is structurally deformed, and the gap width of the liquid crystal layer fluctuates. There is a problem. For example, the coefficient of thermal expansion of each member constituting the liquid crystal display device is 37
× 10 ^-7 / ° C, color filter -6 × 10 ^-7 / °
C, since the TFT is 5 × 10 ⁻⁷ / ° C., such a difference in the coefficient of thermal expansion has an adverse effect.

In the above-described method of performing the defoaming treatment by pressurization for removing bubbles, after the dustproof glass is pressurized, the pressure is released and the pressure is returned to the atmospheric pressure. There is a problem in that backing occurs and air bubbles cannot be completely removed. Also, when dustproof glass is adhered to both sides of the LCD panel adhered and fixed in the outer frame via a thermosetting adhesive, excess adhesive concentrates on the inner corners of the outer frame. There is a problem that the adhesive overflows and runs on the surface side of the outer frame.

Accordingly, an object of the present invention is to provide an LCD panel, which is bonded and fixed in an outer frame, when the dustproof glass is bonded and fixed without heating the adhesive.
It is an object of the present invention to provide a dustproof glass bonding method for a liquid crystal display device which can be fixedly adhered to a CD panel, suppress generation of air bubbles in an adhesive, and suppress overflow of the adhesive.

[0007]

According to the present invention, there is provided an LCD panel to which a flat cable is connected, and an outer frame corresponding to the outer shape of the LCD panel.
A cutout for guiding the flat cable to the outside, an outer frame to which the LCD panel is bonded and fixed via a first adhesive on an inner side, and an LCD panel bonded and fixed in the outer frame. A dustproof glass bonding method for a liquid crystal display device, comprising: a dustproof glass adhered and fixed via a second adhesive; and a parting plate mounted on both sides of the outer frame in a state where the dustproof glass is bonded. A thermosetting adhesive is used for the second adhesive, and the dustproof glass is
When adhering to a CD panel, first, with the second adhesive disposed on the dust-proof glass joint surface of the LCD panel, the dust-proof glass is disposed on the dust-proof glass joint surface at a constant inclination angle, The dustproof glass is the LCD
The second adhesive is crushed into a thin film by gradually rotating and displacing in a direction in which it adheres to the dust-proof glass joint surface of the panel, and the dust-proof glass and the LCD panel are brought into contact with the thin-film second adhesive. Then, the second adhesive is solidified by leaving the second adhesive at room temperature for a certain period of time, so that the dust-proof glass is bonded to the LCD panel.

In the method for bonding dustproof glass of a liquid crystal display device according to the present invention, first, the second surface of the LCD panel is bonded to the dustproof glass.
Place the adhesive. Then, the dust-proof glass is disposed at a fixed inclination angle on the dust-proof glass joint surface of the LCD panel, and then the dust-proof glass is gradually rotated and displaced in a direction in which the dust-proof glass comes into close contact with the dust-proof glass joint surface of the LCD panel. Thus, while the second adhesive is crushed into a thin film by the dust-proof glass, the dust-proof glass and the LCD panel are brought into contact with the second thin-film.
And tightly arranged via the adhesive. After that, the second adhesive is solidified by leaving it at room temperature for a certain period of time, and the dustproof glass is bonded to the LCD panel.

As described above, in the dustproof glass bonding method of the present invention, since the second adhesive is solidified by being left at room temperature for a certain period of time, the heat treatment for solidifying the second adhesive as in the prior art is performed. Therefore, stress due to thermal expansion of the outer frame, the LCD panel, and the dust-proof glass, and curing of the adhesive in a short time can be eliminated. Therefore, each part of the liquid crystal display device is not structurally deformed by the heat treatment, the fluctuation of the gap width of the liquid crystal layer can be prevented, and the quality can be improved.

Further, in the dustproof glass bonding method of the present invention,
When the dust-proof glass is bonded to the LCD panel with the second adhesive, the dust-proof glass, which is arranged obliquely on the dust-proof glass joint surface of the LCD panel, is gradually rotated and displaced, so that the second adhesive is dust-proof. Since the dust-proof glass is brought into close contact with the LCD panel while gradually crushing from one side of the glass bonding surface to the other side, the bonding operation can be performed without bubbles in the second adhesive, and the pressure treatment can be performed. There is no subsequent press-back of bubbles.

Further, in addition to the above-described method, by forming the inner corner portion of the outer frame into an arc shape, the second corner of the inner corner portion can be formed at the time of joining the dustproof glass.
Can be guided so that the adhesive flows toward both sides of the corner portion, and the second adhesive crushed by the dustproof glass can be used.
Part of the adhesive can be prevented from concentrating on the corner portion and overflowing to the surface side of the outer frame.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for bonding dustproof glass of a liquid crystal display device according to the present invention will be described.
FIG. 1 is an exploded perspective view showing an example of a liquid crystal display device to which the dustproof glass bonding method according to the present embodiment is applied. FIG. 2 is a cross-sectional view showing a laminated structure of the liquid crystal display device shown in FIG. 1, and FIG. 3 is a plan view showing an outer frame of the liquid crystal display device shown in FIG.

In the liquid crystal display device used in this embodiment, light from a light source provided in a device main body (not shown) is made incident on the LCD panel 20, and this incident light passes through a color filter (not shown) and is driven by the liquid crystal. The light is modulated and emitted. The outer frame 10, the LCD panel 20, and the dust-proof glasses 30A, 30
B and parting plates 40A, 40B. Outer frame 10
Is a mounting frame for attaching the LCD panel 20 to the apparatus main body, is formed in a rectangular frame shape, and has a rectangular plate-shaped L inside.
The CD panel 20 and the dustproof glasses 30A, 30B are housed, and the parting plates 40A, 40B are mounted on both sides. A plurality of insertion holes 10A through which mounting screws (not shown) for mounting to the apparatus main body are inserted are formed in the outer peripheral portion of the outer frame 10, and one side of the outer frame 10 has an LCD. A notch 10B for guiding the flat cable 24 connected to the panel 20 to the outside is formed.

The LCD panel 20 has a color filter and a TFT which are overlapped with each other and have a liquid crystal enclosed therein.
The TFT controls each liquid crystal pixel to modulate light from the light source described above. This LCD panel 20 is provided with a color filter on the surface on the incident side, and a flat cable 24 is connected from one side. Such L
The CD panel 20 is bonded and fixed to the inside of the outer frame 10 using a positioning step 10D or the like provided inside the outer frame 10, and in this example, a first adhesive ( (Not shown) and fixed by irradiation with ultraviolet rays.

Each of the dust-proof glasses 30A and 30B is L
The CD panel 20 is adhered and fixed to both the entrance side and the exit side of the CD panel 20. In this example, the CD panel 20 is adhered by a second adhesive 32 made of a thermosetting resin, and is kept at room temperature (for example, 23 ° C. to 27 ° C.).
(C) for a fixed time (24 hours).

FIGS. 4A and 4B are an enlarged plan view and an enlarged sectional view showing the configuration of the inner corner portion of the outer frame 10 in this embodiment. In this example, the inner corner portion 10C of the outer frame 10 has a dustproof glass 30 as shown in FIG.
When viewed in the plate thickness direction of A and 30B, it is formed not in a right angle but in an arc-shaped concave shape having a radius of curvature of, for example, about several mm. Further, the inner corner portion 10C is formed as shown in FIG.
As shown in (B), when viewed in the plate surface direction of the dustproof glasses 30A and 30B, the dustproof glasses 30A are formed to incline, for example, around θ = 1 ° in a direction expanding from the inside to the outside of the outer frame 10. . A dustproof glass 30 is provided near the inner corner 10C.
A and a plurality of projections 10E for positioning 30B are formed, and as shown in FIG.
E allows the dust-proof glasses 30A, 30B to be positioned and mounted in the outer frame 10. Thereby, each corner part of dustproof glass 30A, 30B is arrange | positioned in the state which faces the inside corner part 10C of the outer frame 10 by predetermined distance.

In this embodiment, since the inner corner portions 10C and the projections 10E having the above-described shapes are provided, the adhesive 32 is thin-filmed by the dust-proof glasses 30A and 30B in a later-described step of joining the dust-proof glasses 30A and 30B. The inner corner portion 1 of the outer frame 10 when squashed and joined.
The adhesive 32 that has flowed into the inner corner portion 10C is guided by the slightly inclined circular arc surface of the inner corner portion 10C, flows as indicated by an arrow α in FIG. 4A, and is guided to both sides of the inner corner portion 10C. Thus, the excess adhesive 32 can be prevented from being concentrated on the inner corner portion 10C, and can be prevented from overflowing onto the surface of the outer frame 10. In addition, this phenomenon is the result observed also by experiment with a prototype.

After the dust-proof glasses 30A and 30B are mounted, a gap formed between the dust-proof glass 30A on the incident side and the outer frame 10 is filled with an RTV (room temperature curing type) silicone resin or the like for filling. Is injected and solidified. The parting plates 40A and 40B determine the display area of the liquid crystal display device, and have a plurality of engaging claws 42A and 42B provided on the outer peripheral edge thereof formed on the inner portion of the outer frame 10. (Not shown) to be mounted on the outer frame 10.

Next, a method of manufacturing the liquid crystal display device having the above-described configuration will be described. First, the LCD panel 20 is bonded and fixed to the outer frame 10. This is the outer frame 1 as described above.
After applying a first adhesive such as an ultraviolet curable resin to the inside of the frame 0, the LCD panel 20 is mounted on the inside of the frame 10. At this time, the LCD panel 20 is positioned by a positioning step 10D formed inside the frame 10 or the like. Further, the flat cable 24 of the LCD panel 20 is arranged in the cutout portion 10B of the outer frame 10 and is guided to the outside. Next, the dustproof glass 30A is bonded and fixed to the incident side surface (color filter surface) of the LCD panel 20.

FIG. 5 is a side view showing the operation procedure at the time of the adhesive fixing, and shows a state in which the outer frame 10 is omitted.
This operation is performed by the second adhesive 32 using the thermosetting resin as described above. First, as shown in FIG. 5A, a second adhesive 32 is applied on the dust-proof glass bonding surface of the LCD panel 20 (in this case, the color filter surface 20A).
Are arranged in a substantially dome shape, and the dust-proof glass 30A is inclined at a predetermined inclination angle (30 degrees) with respect to the color filter surface 20A.
At least 40 °). That is, FIG.
In the example shown in (A), the second side 2 of the LCD panel 20 opposite to the first side 201 where the flat cable 24 is provided is provided.
02, the second side 302 of the dust-proof glass 30A is made coincident with the first side 301 of the dust-proof glass 30A.
It is arranged in a state separated from the D panel 20.

Then, the first side 301 of the dustproof glass 30A is rotationally displaced so as to gradually approach the LCD panel 20, as shown by the arrow β in FIGS. 5A and 5B. As a result, the second adhesive 32 disposed on the dust-proof glass joining surface 30A of the LCD panel 20 is gradually extruded toward the flat cable 24, and is crushed into a thin film. (FIG. 5 (C)). On this occasion,
Since the second adhesive 32 provided in a dome shape is gradually extruded from the inside to the outside and crushed into a thin film, the dustproof glass 3
Since the contact area between 0A and the second adhesive 32 gradually expands in the radial direction from the center of the dome shape, no gap (bubble) remains between the dustproof glass 30A and the LCD panel 20. , The second adhesive 32 can be pushed out. Therefore, no air bubbles remain in the second adhesive 32 between the dustproof glass 30A and the LCD panel 20.
Therefore, no bubbles are generated by pressback after the defoaming operation by the post-processing as in the related art.

Further, the adhesive 3 is formed by the dustproof glass 30A.
The adhesive 32 that has flowed into the inner corner portion 10C of the outer frame 10 when crushed and joined into a thin film shape is guided by the slightly inclined circular arc surface of the inner corner portion 10C, as shown in FIG. Since the flow becomes as shown by the arrow α and is guided to both sides of the inner corner portion 10C, the excess adhesive 32 can be prevented from being concentrated on the inner corner portion 10C, and the outer frame 10 can be prevented.
Can be prevented from spilling over the surface.

Also, as described above, the LCD panel 20
After adhering the dustproof glass 30A on the color filter surface 20A side of the LCD panel 20, the TF
The dustproof glass 30B on the T surface 20B side is bonded. After this,
The film thickness of the second adhesive 32 is made constant, and a pressure treatment for defoaming is performed. This is performed by applying a uniform pressure to the dust-proof glasses 30A and 30B by a pressurizing device (autoclave).
The operation is performed at a pressure of 1 kg / cm ² and a working time of 0.5 hour.

Next, in order to solidify the second adhesive 32,
Outer frame 10, LCD panel 20, and dustproof glass 30A,
30B is bonded at room temperature (for example, 23 ° C to 2 ° C).
(7 ° C) for a certain period of time (24 hours). Thereby, the second adhesive 32 can be solidified without heating, and the outer frame 1
0, LCD panel 20, and dustproof glass 30A, 30B
It is possible to avoid a difference in the coefficient of thermal expansion of each material and a stress on each part due to the solidification of the thermosetting resin in a short time, and it is possible to prevent a change in the gap of the liquid crystal layer. Note that, in the present invention, the normal temperature means an environmental temperature in a step before the second adhesive 32 is solidified, and after the LCD panel 20 and the dust-proof glass 30A, 30B are bonded by the second adhesive 32. ,
It is preferable that the adhesive 32 be kept at a constant temperature for a period of time for solidifying the adhesive 32 (24 hours in this example). For example, the temperature may fluctuate around 10 ° between night and day,
The joined body of the outer frame 10, the LCD panel 20, and the dust-proof glasses 30A and 30B is stored in a temperature-controlled environment that does not receive such a change in air temperature.

Next, after the solidification of the second adhesive 32 is completed, an RTV (room temperature hardening system) is provided in a gap formed between the dust-proof glass 30A on the incident side and the outer frame 10. After the third adhesive 34 using silicon resin or the like is injected and solidified, the parting plates 40A and 40B are mounted.

[0026]

As described above, in the method for bonding dustproof glass of a liquid crystal display device according to the present invention, a thermosetting adhesive is used as an adhesive for bonding and fixing dustproof glass to an LCD panel bonded and fixed in an outer frame. And dustproof glass with LC
In the case of bonding to the D panel, first, the dust-proof glass is arranged at a certain inclination angle on the dust-proof glass joint surface with the adhesive disposed on the dust-proof glass joint surface of the LCD panel. By gradually rotating and displacing in the direction in which it adheres to the glass bonding surface, the dust-proof glass and the LCD panel are closely arranged via the thin-film adhesive while crushing the adhesive into a thin film. Was allowed to stand at room temperature for a certain period of time to solidify, and the dustproof glass was bonded to the LCD panel.

For this reason, in the dustproof glass bonding method of the present invention, since the adhesive is solidified by being left at room temperature for a certain period of time, the conventional heat treatment for solidifying the adhesive is not performed. In addition, the thermal expansion of the outer frame, the LCD panel, and the dustproof glass, and the stress caused by the hardening of the adhesive in a short time can be eliminated. Therefore, each part of the liquid crystal display device is not structurally deformed by the heat treatment, the fluctuation of the gap width of the liquid crystal layer can be prevented, and the quality can be improved.

Further, in the dustproof glass bonding method of the present invention,
When the dustproof glass is bonded to the LCD panel with an adhesive, the adhesive is gradually rotated and displaced from the dustproof glass bonding surface of the LCD panel so that the adhesive is removed from one of the dustproof glass bonding surfaces. Since the dust-proof glass is brought into close contact with the LCD panel while being gradually crushed toward the other side, the joining operation can be performed without bubbles in the adhesive, and press-back of bubbles after the pressure treatment does not occur. .

Further, in addition to the dustproof glass joining method of the present invention as described above, by forming the inner corner portion of the outer frame into an arc shape, the adhesive at the inner corner portion can be formed at the time of joining the above dustproof glass. Can be guided so as to flow toward both sides of the corner portion, and a part of the adhesive crushed by the dustproof glass can be prevented from concentrating on the corner portion and overflowing to the surface side of the outer frame.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of a liquid crystal display device to which a dustproof glass bonding method according to an embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view showing a laminated structure of each substrate of the liquid crystal display device shown in FIG.

FIG. 3 is a plan view showing an outer frame of the liquid crystal display device shown in FIG.

FIG. 4 is an enlarged plan view and an enlarged cross-sectional view showing a configuration of an inner corner portion of an outer frame of the liquid crystal display device shown in FIG.

5 is a side view showing an operation procedure at the time of bonding and fixing an LCD panel and dustproof glass in the liquid crystal display device shown in FIG. 1;

[Explanation of symbols]

10 outer frame, 10C inner corner, 20 LC
D panel, 24 Flat cable, 30A, 30B
... dust-proof glass, 32 ... second adhesive, 40A, 40
B ... A parting board.

Claims (10)

[Claims] 1. An LCD panel to which a flat cable is connected, an outer frame corresponding to the outer shape of the LCD panel, a cutout for guiding the flat cable to the outside, and a first adhesive on an inner portion. An outer frame to which the LCD panel is adhered and fixed through the second frame;
A dust-proof glass bonded and fixed via an adhesive, and a parting plate attached to both sides of the outer frame in a state where the dust-proof glass is bonded. When a thermosetting adhesive is used as the adhesive of No. 2 and the dustproof glass is bonded to the LCD panel, first, the second adhesive is disposed on the dustproof glass joining surface of the LCD panel, The dust-proof glass is disposed at a fixed inclination angle on the dust-proof glass joining surface, and then the dust-proof glass is gradually rotated and displaced in a direction in which the dust-proof glass comes into close contact with the dust-proof glass joining surface of the LCD panel, so that the second bonding is performed. While crushing the agent into a thin film, the dust-proof glass and the LCD panel are closely placed via the second adhesive in the form of a thin film, and then the second adhesive is kept at room temperature for a certain period of time. It solidified by location, the dust-proof glass and so joined to the LCD panel, dustproof glass bonding method of the liquid crystal display device, characterized in that. 2. The inside corner portion of the outer frame prevents a part of the second adhesive crushed by the dust-proof glass from concentrating on the corner portion and overflowing to the surface side of the dust-proof glass. 2. The method as claimed in claim 1, wherein the second adhesive is formed in an arc shape for guiding the flow of the second adhesive to both sides of the corner portion. 3. When the dust-proof glass is arranged at a fixed angle of inclination on the dust-proof glass joint surface of the LCD panel, the first side of the LCD panel formed in a square plate shape is opposite to the first side on which the flat cable is provided. A second side of the dust-proof glass formed in a square plate shape is made to coincide with a second side of the dust-proof glass, and the first side of the dust-proof glass is arranged in a state of being separated from the LCD panel; Is gradually displaced so as to gradually approach the LCD panel side, so that the second adhesive disposed on the dust-proof glass joint surface of the LCD panel is pushed out toward the flat cable side while the second adhesive is pressed against the dust-proof glass side. 2. The method as claimed in claim 1, wherein the LCD panel is closely attached to the LCD panel via the second adhesive. 4. The method as claimed in claim 1, wherein the first adhesive is an ultraviolet-curable adhesive. 5. The fixed inclination angle is 30 ° or more and 40 ° or more.
2. The method for bonding dustproof glass of a liquid crystal display device according to claim 1, wherein the angle is in the range of not more than .degree. 6. The method according to claim 6, further comprising a step of pressing the dust-proof glass against the LCD panel with a constant uniform pressure after closely attaching the dust-proof glass and the LCD panel via the thin film-shaped second adhesive. The method for bonding dustproof glass of a liquid crystal display device according to claim 1, wherein: 7. After the dust-proof glass is bonded and fixed to the LCD panel in the outer frame, a third adhesive is filled in a gap formed between the outer frame and the LCD panel and the dust-proof glass to be solidified. 2. The method according to claim 1, further comprising attaching the parting plate to the outer frame. 8. The method as claimed in claim 1, wherein the third adhesive is an RTV type adhesive. 9. The parting plate is mounted on the outer frame by fitting a locking claw provided on an outer peripheral edge of the parting plate with an engaging portion formed on an inner portion of the outer frame. The method for bonding dustproof glass of a liquid crystal display device according to claim 1. 10. The method according to claim 1, wherein a plurality of projections for positioning the dust-proof glass are provided inside the outer frame.