JP2001311938A - Liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Problem] Color filter, cover glass plate and TFT
Provided is an LCD in which bubbles, particles, and the like do not exist between the substrate and the substrate. SOLUTION: This LCD 30 has a TFT substrate 12 and a T
The color filter 14 which is in close contact with the FT substrate, and two cover glass plates 16A and 16B which are respectively adhered to the surface of the color filter opposite to the TFT substrate and the surface of the TFT substrate opposite to the color filter. And a quadrangular cylindrical outer frame 32 with upper and lower openings that accommodates the laminated body. The outer frame body has a tapered side wall, and a protrusion 36 protruding inward of the outer frame body is provided.
It is provided on the tapered inner wall surface 34 on the four sides of the outer frame body, and substantially contacts the cover glass plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display (L).
CD), more specifically, color filters and TF
The present invention relates to an LCD in which bubbles, foreign matter, particles, and the like do not exist between a T substrate and a cover glass plate.

[0002]

2. Description of the Related Art Liquid crystal display devices (hereinafter referred to as LCDs).
Is a TFT substrate, a color filter that is in close contact with the TFT substrate, and two covers adhered to the surface of the color filter opposite to the TFT substrate and the surface of the TFT substrate opposite to the color filter, respectively. A quadrangular prism-shaped laminate made of a glass plate is housed in a quadrangular cylindrical outer frame body with upper and lower openings. The TFT substrate includes a liquid crystal, an electrode for driving the liquid crystal,
The cover glass plate is a transparent glass plate provided as a color filter and a protection plate for the TFT substrate, and is formed as a liquid crystal display element having a TFT for controlling electrodes, a polarizing plate, and the like.

Here, the configuration of a conventional LCD will be described with reference to FIGS. 6 and 7. FIG. 6 and 7 show, respectively,
It is the top view and sectional drawing of the conventional LCD. Conventional LCD
Reference numeral 10 denotes a TFT substrate 12 as shown in FIGS.
And a color filter 14 adhered on the TFT substrate 12.
And two transparent cover glass plates 16A, B adhered to the surface of the color filter 14 opposite to the TFT substrate 12 and the surface of the TFT substrate 12 opposite to the color filter 14, respectively. It is composed of a columnar laminated body 18 and a rectangular tubular outer frame 20 with a vertically opened opening that houses the laminated body 18.

[0004] The cover glass plate 16A is bonded to the surface of the cover glass plate 14 opposite to the TFT substrate 12 by a silicone resin layer 22A. The cover glass plate 16B is bonded to the surface of the TFT substrate 12 opposite to the color filter 14 by a silicone resin layer 22B. The TFT substrate 12 and the color filter 14 of the laminate 18 are adhered to the inner wall surface of the outer frame 20 with an adhesive (not shown). As shown in FIGS. 6 and 7, the outer frame body 20 is a quadrangular cylindrical part having upper and lower openings and tapered side walls 24 in all directions, and a lower opening having substantially the same size as the cover glass plate 16B. And the height is approximately the same as the thickness of the laminate 18. As shown in FIG. 7, the outer frame body 20 has a gap g of 0.1 mm or less on average at the lower opening edge with respect to the cover glass plate 16 </ b> B, and the tapered side wall expands from the lower part to the upper part. 24.

[0005] Next, with reference to FIGS. 8A and 8B, steps of manufacturing a conventional LCD will be described. FIG. 8 is a flowchart showing a manufacturing process of a conventional LCD in a partial sectional side view. First, as shown in FIG. 8A, a laminated structure in which the color filter 14 is closely attached to the TFT substrate 12 is inserted into the outer frame 20, and the laminated structure and the outer frame 20 are bonded with an adhesive (not shown). )). Next, as shown in FIG. 8B, a silicone resin is applied as an adhesive to the upper surface of the color filter 14 and the lower surface of the TFT substrate 12, respectively, to form silicone resin layers 22A and 22B. Subsequently, as shown in FIG. 8C, the cover glass plates 16A and 16B are bonded to the silicone resin layer 22A on the upper surface of the color filter 14 and the silicone resin layer 22B on the lower surface of the TFT substrate 12, and
The CD 10 is formed.

By the way, a silicone resin is applied as an adhesive to the upper and lower surfaces of the laminated structure to form a silicone resin layer 22A,
When forming B, the coated and formed silicone resin layer 22
In A and B, bubbles are inevitably caught and remain. Therefore, usually, after the cover glass plates 16A and B are adhered to the upper and lower surfaces of the laminated structure, the pressure is applied to the cover glass plates 16A and B by applying the pressure to the autoclave and bubbles are pushed out from the silicone resin layers 22A and B. .

[0007]

However, the above-mentioned LC
In forming the LCD according to the conventional manufacturing method of D, in the final stage, pressure is applied to the cover glass plates 16A, 16B of the LCD 10 by applying pressure to the cover glass plates 16A, B of the LCD 10 to push out bubbles from the silicone resin layers 22A, B, Quite
It is difficult to completely extrude bubbles from the silicone resin layers 22A and 22B. In addition, when foreign matter, particles, and the like exist on the color filter, bubbles are easily generated. Therefore, it is necessary to prevent foreign matter, particles, and the like from being present on the color filter. However, in the conventional LCD, as shown in FIGS. 9A and 9B, bubbles, foreign matter, and particles are generated. It often remained. If air bubbles, foreign matter, particles, and the like remain, display defects caused by the remaining bubbles may occur in an image displayed on the liquid crystal display surface of the liquid crystal display device, so that it is difficult to improve the LCD product yield. there were.

[0008] Therefore, an object of the present invention is to provide a method for controlling the presence of bubbles, foreign matter, and the like between a color filter and a cover glass plate or a TFT substrate.
An object of the present invention is to provide an LCD in which particles and the like do not exist.

[0009]

As a result of research, the present inventor has found that bubbles are hardly pushed out of the silicone resin layer because in the conventional LCD, the outer edge of the cover glass plate and the inner wall of the outer frame body are on average. Since there is only a gap of 0.1 mm or less and almost close contact, excess silicone resin is difficult to be extruded from between the cover glass plate and the color filter and between the cover glass plate and the TFT substrate, and It has been found that the extruded silicone resin does not have a stagnant liquid pool. Then, the inventors conceived of providing a projection on the inner wall of the outer frame body to provide a gap between the cover glass plate and the inner wall of the outer frame body, and arrived at the present invention after experiments.

In order to achieve the above object, a liquid crystal display device of the present invention comprises a TFT substrate formed as a liquid crystal display element having a liquid crystal, an electrode for driving the liquid crystal, a TFT for controlling the electrode, a polarizing plate, and the like; A square consisting of a color filter that is in close contact with the TFT substrate, and two cover glass plates that are respectively adhered to the surface of the color filter opposite to the TFT substrate and the surface of the TFT substrate opposite to the color filter. In a liquid crystal display device in which a columnar laminated body is housed in a square tubular outer frame body with upper and lower openings, projections projecting toward the laminated body are formed on the inner wall surfaces of the square tubular outer frame body on four sides.
Each is characterized by being provided.

Preferably, the shape and size of the projections are not limited as long as the projections are not so large that the laminated body cannot be accommodated in the outer frame. 0.8 mm or more and 1.5 mm or less, with a radius of curvature of 0.
2 mm or more and 0.6 mm or less, semi-circular projection, or projection thickness of 0.8 mm or more and 1.5 mm or less; Any of the following quadrangular projections,
The gap between the cover glass plate and the inner wall surface of the outer frame body in the region excluding the protrusion is 0.2 mm or more and 0.8 mm or less.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First Embodiment FIGS. 1 and 2 are a plan view showing the configuration of an LCD according to the present embodiment, a cross-sectional view taken along line II of FIG. 1, and FIGS. 3 (a) and 3 (b) respectively. FIG. 4 is an enlarged view of the rear surface of the projection, and FIG. 4 is an enlarged view of the rear surface of another projection. The liquid crystal display device (hereinafter, referred to as LCD) 30 of the present embodiment.
1 has the same configuration as the conventional LCD 10 except for the configuration of the outer frame 32, as shown in FIGS. That is, the LCD 30 includes the TFT substrate 12 and the TFT substrate 12.
The color filter 14 and the color filter 1
4 and the surface opposite to the TFT substrate 12 and the TFT substrate 12
A rectangular column-shaped laminate 18 composed of two transparent cover glass plates 16A and 16B adhered to the surface opposite to the color filter 14, And the outer frame body 32 of FIG.

As shown in FIGS. 1 and 2, the outer frame 32 has two projections 36 spaced apart from the lower opening edges of the first and third tapered side walls 34A and 34C, and the second projection 36, respectively. And one each on the lower opening edge of the fourth tapered side walls 34B and 34D.
Of the laminated body 18.
At its tip against the cover glass plate 16B.

The protrusions 36 are all the same type of protrusions provided so as to protrude from the lower opening edge of the outer frame body 32 toward the inner laminated body 18, and are shown in FIGS. As shown in b), it is a semi-disc-like projection having a projection thickness T of 1.1 mm and a radius of curvature R of 0.2 mm or more and 0.6 mm or less. The protrusion 36 of the first tapered side wall 34A and the third
The distance between the tapered side wall 34C and the protrusion 36 is
It is the same as the distance between the corresponding lower opening edges of the outer frame 20 of the CD 10. Similarly, the distance between the protrusion 36 of the second tapered side wall 34B and the protrusion 36 of the fourth tapered side wall 34D is the same as the distance between the corresponding lower opening edges of the outer frame 20 of the conventional LCD 10. . In addition, as the protrusion 36,
As shown in FIG. 3B, instead of the semi-circular projection, the thickness T of the projection is 1.1 mm, and the dimension P of the projection is 0.2 mm or more and 0.6 mm or less as shown in FIG. , Width W is 0.2m
It may be a square pillar-shaped protrusion having a length of not less than m and not more than 0.6 mm.

The LCD 30 of the present embodiment is a conventional L
It is produced in the same manner as CD10. That is, first, FIG.
As shown in (a), a laminated structure in which the color filter 14 is adhered to the TFT substrate 12 is inserted into the outer frame 32,
The laminated structure and the outer frame 32 are bonded with an adhesive. Then
As shown in FIG. 8B, a silicone resin is applied as an adhesive to the upper surface of the color filter 14 and the lower surface of the TFT substrate 12 to form silicone resin layers 22A and 22B.
Subsequently, the cover glass plate 16B is positioned by bringing the cover glass plate 16B into contact with the projecting portion 36, and the cover glass plates 16A and 16B are placed on the upper surface of the color filter 14 and the lower surface of the TFT substrate 12, as shown in FIG. LCD3
0 is formed. Further, after the cover glass plates 16A and 16B are adhered to the upper and lower surfaces of the laminated structure, they are put in an autoclave and pressure is applied to the cover glass plates 16A and 16B to push out bubbles from the silicone resin layers 22A and 22B.

In the LCD 30 of the present embodiment, since the outer frame 32 has the projection 36, the lower opening edge of the outer frame 32 and the cover glass plate 16B of the laminated body 18 Is widened from 0.2 mm to 0.6 mm. Therefore, after the cover glass plates 16A and 16B are adhered to the upper and lower surfaces of the laminated structure to form the laminate 18, the pressure is applied to the cover glass plates 16A and 16B by applying the pressure to the autoclave, and the silicone resin layers 22A and B When extruding air bubbles from the silicone resin, the silicone resin easily flows out. That is, when the pressure is applied, the silicone resin and the TFT substrate 12 between the cover glass plate 16A and the color filter 14A are formed.
Since the silicone resin between the cover glass plate 16B and the cover glass plate 16B spreads thinly, excess silicone resin is extruded from the outer peripheral portion, the silicone resin layers 22A and 22B become thinner, and air bubbles and particles are extruded together with the silicone resin. It is.

Test Example 1 In order to evaluate the LCD 30 according to the present embodiment, a large number of LCDs 3 were set up using the conventional LCD 10 described above as a conventional example.
The same number of LCDs 10 as those of 0 were inspected to calculate the ratio of the LCD 30 and the LCD 10 in which bubbles exist and the ratio of the LCD 30 and the LCD 10 in which foreign matter and particles exist, and the following results were obtained. Existence ratio of foreign matter and particles Existence ratio of air bubbles Conventional LCD 10 2.7% 0.3% LCD 30 of the present embodiment 0.3% 0% As described above, the LCD 30 of the present embodiment has The ratio of the existing LCD 30 was almost zero (0), and the ratio of the LCD 30 in which foreign matters, particles, and the like were present was significantly smaller than that of the conventional LCD 10.

Test Example 2 In order to evaluate the LCD 30 of this embodiment, the conventional LCD 10 described above was used as a conventional example,
That is, the adhesiveness between the cover glass plate 16A and the color filter 14A and the TFT substrate 12 and the cover glass plate 16A
In order to evaluate the adhesiveness with B, a rotation torque durability test was performed in the following manner. With reference to FIG. 5, the point of the rotation torque durability test will be described. First, the LCD sample is fitted into the fitting hole 42 of the rotation torque measuring jig 40. Then
The LCD driver is sandwiched by the torque driver 44, and the torque driver 44 is turned to check how many kilos of torque the silicone resin has been peeled off while looking at the microscope. The result of the rotation torque endurance test shows that in the conventional LCD 10, the average torque at which the silicone resin was peeled off was 2.95 × 9.8 × 10 ^4.
Of the LCD 30 according to the present embodiment,
In Table 1, the average torque was 3.6 × 9.8 × 10 ⁴ Pa.

The LCD 30 of the present embodiment is a conventional L
This is considered to be because foreign substances, particles, and air bubbles in the silicone resin layer are extruded together with the silicone resin and reduced as compared with CD10, so that the bonding area increases and the bonding property improves.

[0020]

According to the present invention, a quadrangular prism-shaped laminate composed of a TFT substrate, a color filter, and two cover glass plates adhered respectively to the color filter and the TFT substrate is surrounded by an outer frame. The following effects can be obtained by providing the projections projecting toward the inside of the outer frame, that is, toward the laminated body, on the four inner wall surfaces of the outer frame. (1) Since the outer frame has a projection, the gap between the lower opening edge of the outer frame and the cover glass plate is widened in a region excluding the projection, and the cover glass plate is attached to the upper and lower surfaces of the laminated structure. After that, when put in an autoclave and apply pressure to the cover glass plate to push out bubbles from the silicone resin layer, the silicone resin layer between the cover glass plate and the color filter and the TFT substrate and the cover glass plate As the silicone resin layer spreads thinly, excess silicone resin is extruded from the outer periphery, and the silicone resin layer becomes thinner,
Bubbles, particles and the like are extruded together with the silicone resin. Therefore, the presence of bubbles can be reliably reduced. (2) The presence of foreign matter and particles can be reliably reduced. (3) By reducing bubbles, foreign matter, and particles, the integrity of the LCD, that is, the adhesion of the cover glass plate is improved. (4) Therefore, the product yield of the LCD is greatly improved, and the reliability of the image quality and mechanical strength of the LCD is improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of an LCD according to an embodiment.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIGS. 3A and 3B are an enlarged rear view and an enlarged side view of a protrusion.

FIG. 4 is an enlarged back view of another protrusion.

FIG. 5 is a diagram for explaining a point of a rotation torque durability test.

FIG. 6 is a plan view of a conventional LCD.

FIG. 7 is a sectional view taken along line II-II in FIG. 6;

FIG. 8 is a flowchart showing a conventional LCD manufacturing process.

9 (a) and 9 (b) are views for explaining the problems of the conventional LCD, and FIG. 9 (b) is a cross-sectional view.

[Explanation of symbols]

10 ... conventional LCD, 12 ... TFT substrate, 14 ...
Color filter, 16 cover glass plate, 18 laminate, 20 outer frame, 22 silicone resin layer, 3
0: LCD of the embodiment, 32: outer frame, 34:
... Tapered side wall, 36.

Continuing from the front page (72) Matsumoto Yoneyama 5-1 Noguchikita, Kokubu-shi, Kagoshima F-term in Sony Kokubu Corporation (reference) 2H089 HA40 JA10 QA02 QA08 TA06 TA12 5G435 AA11 BB12 EE05 EE13 EE34 GG12 KK02 KK05

Claims (2)

[Claims] 1. A TFT substrate formed as a liquid crystal display element having a liquid crystal, an electrode for driving the liquid crystal, a TFT for controlling the electrode, a polarizing plate, a color filter in close contact with the TFT substrate, and a color filter. A quadrangular prism-shaped laminate consisting of two cover glass plates adhered to the surface opposite to the TFT substrate and to the surface of the TFT substrate opposite to the color filter is a rectangular cylindrical outer frame with upper and lower openings. A liquid crystal display device housed in a body, wherein projections protruding toward a laminate are provided on four inner wall surfaces of a rectangular cylindrical outer frame, respectively. 2. The method according to claim 1, wherein the protrusion has a protrusion thickness of 0.8 mm or more.
5 mm or less, semi-disc-like projection having a curvature radius of 0.2 mm or more and 0.6 mm or less, or a projection thickness of 0.8 mm or more and 1.5 m
m or less, and any one of square pillar-shaped protrusions having a protrusion size of 0.2 mm or more and 0.6 mm or less and a protrusion width of 0.2 mm or more and 0.6 mm or less. The liquid crystal display device according to claim 1, wherein a gap between the inner wall surface of the frame and the inner wall is 0.2 mm or more and 0.8 mm or less.