JP2003270651A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which can suppress the penetration of a liquid crystal sealing member into a display region. <P>SOLUTION: The liquid crystal display device has a liquid crystal driving substrate 1, a counter substrate 2, and the sealing member 4. The sealing member 4 comprises a frame-like part 4a having an opening 11 and projecting parts 4b and 4c. The projecting parts 4b and 4c and the two substrates form an injection passage 12. Within a region which forms the injection passage 12 of at least either of the two substrates, a step part 13 is formed so that a distance L<SB>1</SB>at the inlet side of the injection passage 12 becomes longer than a distance L<SB>2</SB>at the side of the outlet of the injection passage 12. When the opening length of the opening 11 is (a), the minimum width of the projecting part 4b measured in parallel with the opened face of the opening 11 is (b), the minimum width of the projecting part 4c measured in parallel with the opened face of the opening 11 is (c), and the minimum distance between the projecting part 4b and the projecting part 4c at the inlet side of the injection passage 12 of the step part 13 is (A), the sealing member 4 is formed so as to satisfy the relation of 'a≤A≤(a+b+c)'. <P>COPYRIGHT: (C)2003,JPO

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, and more particularly to a liquid crystal display device capable of suppressing the occurrence of display unevenness due to penetration of a liquid crystal sealant into the display area.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been widely used for display screens of AV / OA equipment and the like. Also, AV
OA equipment and the like are required to be small and compact, and liquid crystal display devices also need to meet the demand. Therefore, in designing a liquid crystal display device, a liquid crystal drive substrate,
Modules and housings, which are composed of a counter substrate and a liquid crystal drive circuit, have been made smaller and more compact.

FIG. 5 (a) is a cross-sectional view of a conventional liquid crystal display device taken along the thickness direction, and FIG. 5 (b) is a cross-section taken along the cutting line BB 'in FIG. 5 (a). It is a figure. Figure 5
As shown in (a), the liquid crystal display device includes a liquid crystal drive substrate 6
A liquid crystal 63 is sealed between 1 and a counter substrate 62 facing it.

A protective film 65 and an alignment film 66 are sequentially provided on a surface of the liquid crystal driving substrate 61 facing the counter substrate 62 (hereinafter referred to as "opposing surface of the liquid crystal driving substrate"). A protective film 67, a common electrode (ITO) 68, and an alignment film 69 are sequentially provided on a surface of the counter substrate 62 facing the liquid crystal drive substrate 61 (hereinafter, “counter surface of the counter substrate”).

The seal member 64 is sandwiched between the liquid crystal driving substrate 61 and the counter substrate 62, and forms a space for filling the liquid crystal 63. As shown in FIG. 5B, the seal member 64 is
A frame-shaped portion 64 formed in a frame shape having an opening 71 in part
a and a pair of projecting portions 64b and 64 formed so as to project from both ends of the opening 71 to the outside of the frame-shaped portion 64a.
It is composed of c and. The protrusions 64b and 64c form an injection path 72 for injecting the two substrates and the liquid crystal into the inside of the frame-shaped portion 64a. After the liquid crystal is injected, the injection path 72 is sealed by the liquid crystal sealing member 70.

[0006]

However, as shown in FIG.
As shown in (b), in recent liquid crystal display devices,
Injecting passage 72 to achieve the demand for compactness and compactness
The design is made so that the distance d between the end portion on the entrance side of and the display area H is reduced. Therefore, depending on the condition when the injection channel 72 is sealed by the liquid crystal sealing member 70, the liquid crystal sealing member 70 reaches the inside of the display area H as shown in FIG. A part of the stop member 70 may be hardened inside the display area H.

Further, the liquid crystal sealing member 70 that has entered may be mixed with the liquid crystal 63 before being completely cured, and the alignment of the liquid crystal 63 may be disturbed. In such a case, display unevenness occurs in the display area H, which causes a defect in the liquid crystal display device.

An object of the present invention is to solve the above problems and to provide a liquid crystal display device which can prevent the liquid crystal sealing member from entering the display area.

[0009]

In order to achieve the above object, a liquid crystal display device according to the present invention comprises a liquid crystal driving substrate, a counter substrate facing the liquid crystal driving substrate, and a space sandwiched between the two substrates and filled with liquid crystal. A seal member to be formed, wherein the seal member is a frame-shaped portion formed in a frame shape having an opening,
It is composed of a pair of protrusions protruding from both ends of the opening to the outside of the frame, and the protrusions form two substrates and an injection path for injecting liquid crystal into the inside of the frame. In the liquid crystal display device, at least one of the two substrates has a step portion in a region that forms the protrusion and the injection path, and the step portion is located on the inlet side of the injection path with respect to the step portion. The distance between two substrates is set to be longer than the distance between two substrates on the outlet side of the injection path, the opening length of the opening is a, and one protrusion is measured parallel to the opening surface of the opening. The minimum width of the portion is b, the minimum width of the other protruding portion measured parallel to the opening surface of the opening is c, and the minimum distance between the one protruding portion and the other protruding portion on the inlet side of the injection path of the step portion is When A is set, a ≦
It is characterized in that the relationship of A ≦ (a + b + c) is satisfied.

In the liquid crystal display device according to the present invention, the distance from the step portion to the inlet end of the injection path is 0.
It is preferably 1 mm or more and 1.5 mm or less.

Further, in the liquid crystal display according to the present invention, a first protective film and a first alignment film are sequentially provided on a surface of the liquid crystal driving substrate which faces the counter substrate, and the liquid crystal driving substrate of the counter substrate faces the liquid crystal driving substrate. It is preferable that the second protective film, the common electrode, and the second alignment film are sequentially provided on the surface to be covered.

In this aspect, at least one end of the first protective film and the second protective film is located in the injection path, and the step is formed by at least one end. can do. In this case, the thickness of the first protective film and the thickness of the second protective film may be 0.1 μm or more and 20 μm or less.

Further, the end of the common electrode is located in the injection path, and the step is formed by the end of the common electrode, or at least one of the first alignment film and the second alignment film. It is also possible to adopt a mode in which the end portion is located in the injection path and the step is formed by at least one end portion. In this case, the thickness of the common electrode, the first alignment film, and the second alignment film may be 0.05 μm or more and 0.5 μm or less.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A liquid crystal display device according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. 1A is a cross-sectional view of the liquid crystal display device according to the first embodiment of the present invention cut in the thickness direction, and FIG. 1B is a sectional line AA ′ in FIG. It is sectional drawing cut | disconnected along. 2 is shown in FIG.
It is sectional drawing which expands and shows the injection path shown in (b).

As shown in FIG. 1A, the first embodiment
The liquid crystal display device according to the present invention has a liquid crystal drive substrate 1, a counter substrate 2 arranged to face the liquid crystal drive substrate 1, and a seal member 4 which is sandwiched between the two substrates to form a space for filling the liquid crystal 3. ing.

Further, as shown in FIG. 1B, the seal member 4 is composed of a frame-shaped portion 4a formed in a frame shape and a pair of protruding portions 4b and 4c. The frame-shaped portion 4a is provided with an opening 11, and the protrusions 4b and 4c are formed so as to project from both ends of the opening 11 to the outside of the frame-shaped portion 4a. The protrusions 4 b and 4 c together with the two substrates 1 and 2 form an injection path 12 for injecting the liquid crystal 3 into the frame-shaped part 4 a.

The dotted line 14 in FIGS. 1B and 2 is used.
Shows the boundary between the frame-shaped portion 4a and the protruding portions 4b and 4c and the end portion on the outlet side (outlet end) of the injection path 12, but in the first embodiment, the frame-shaped portion 4a and the protruding portion 4b. And 4c are integrally formed. In this specification, the portions protruding from the outer edge of the frame-shaped portion 4a are the protruding portions 4b and 4c.

When the filling of the liquid crystal 3 from the injection channel 12 to the inside of the frame-shaped portion 4a is completed, the injection channel 12 is filled with the liquid crystal sealing member 10.
Sealed by. The dotted line H in FIG.
The area surrounded by corresponds to the display area of the liquid crystal display device according to the first embodiment. The display area H is located inside the frame-shaped portion 4a.

Also in the first embodiment, similarly to the conventional example, the liquid crystal drive substrate 1 is formed by providing TFTs and pixel electrodes in an array on a glass substrate, and the counter substrate 2 is a glass substrate on which a black matrix or a color matrix is formed. It is formed by providing a filter and the like. Further, on the facing surface of the liquid crystal drive substrate 1,
A first protective film 5 and a first alignment film 6 are sequentially provided, and a second protective film 7, a common electrode 8 and a common electrode 8 are provided on the facing surface of the counter substrate 2.
And an alignment film 9 are provided in that order.

The first protective film 5 and the second protective film 7 are general protective films and have a thickness of 0.1 μm or more and 20 μm or more.
It is set within the following range. The common electrode is also a common electrode, and its thickness is 0.05 μm or more and 0.5 μm.
It is set within the following range. In addition, the first alignment film 5
The second alignment film 6 is also a general alignment film, and its thickness is set in the range of 0.05 μm or more and 0.5 μm or less.

However, unlike the conventional example, in the first embodiment, the first protective film 5 and the second protective film 7 are provided so that their ends are located in the injection path 12. . Therefore, in the regions where the protrusions 4b and 4c and the injection path 12 are formed in the liquid crystal drive substrate 1 and the counter substrate 2 by the end portions of the first protective film 5 and the second protective film 7,
The step portion 13 is formed.

Further, in the step portion 13, the distance L1 between the two substrates on the inlet side of the injection path with respect to the step portion 13 is longer than the distance L2 between the two substrates on the outlet side of the injection path. Is formed in. Therefore, the step portion 13 serves as a wall when the liquid crystal sealing member 10 flows into the display region H.

In the first embodiment, the step portion 13 is formed by the protective film provided on each substrate, but the present invention is not limited to this example. Step portion 13
May be formed by a film other than the protective film or a member provided separately, or may be formed by combining two or more kinds of films.

However, from the viewpoint that the number of manufacturing steps is not increased, it is preferable that the step portion 13 is usually formed by using a film provided on the liquid crystal drive substrate 1 or the counter substrate 2 as in the first embodiment. It is a mode. In addition, the stepped portion 13 is shown in FIG.
It is not limited to the one-stage type as shown in (a), but may be a multi-stage type having two or more stages.

The position where the stepped portion 13 is provided is not particularly limited as long as it is within the region where the injection path 12 is formed in the two substrates, and it depends on the type and amount of the liquid crystal sealing member used. It can be set appropriately. For example, the end faces (step faces) of the protective films 5 and 7 may be aligned with the outlet end 14 of the injection path 12. However, from the viewpoint of sufficiently exerting the function of the step portion 13, the above-mentioned FIG.
As shown in (a), the case where the end surfaces (step surfaces) of the protective films 5 and 7 coincide with the end portion on the inlet side (inlet end) of the injection path 12 is excluded.

In the first embodiment, the distance B from the step surface to the inlet end of the injection passage 12 (see FIG. 2) is set to 0.1 mm or more in order to sufficiently exert the action of the step portion. preferable. The upper limit of the distance B will be described later.

In FIG. 2, a indicates the opening length of the opening 11. Further, b indicates the minimum width of the protrusion 4b measured parallel to the opening surface of the opening 11, and c indicates the minimum width of the protrusion 4c measured parallel to the opening surface of the opening 11. Further, A indicates the minimum distance between the protrusion 4b and the protrusion 4c on the inlet side of the injection path 12 of the step portion 13.

In the first embodiment, the opening length a, the minimum width b of the protrusion 4b, the minimum width c of the protrusion 4c, and the protrusion 4b.
The minimum distance A between the protrusion 4c and the protrusion 4c needs to satisfy the relationship of a ≦ A ≦ a + b + c. This is because if the length of each part is set so as to satisfy this relationship, the shape of the injection path 12 is tapered from the inlet to the outlet, or a straight tubular shape in which the inlet and the outlet are equal in size. This is because the liquid crystal sealing member 10 receives a drag force from the protrusions 4b and 4c at the time of injection, and it is difficult for the liquid crystal sealing member 10 to invade deeper.

Specifically, in the first embodiment, the opening length a is 3 mm, the minimum width b of the protruding portion 4b is 1.2 mm, the minimum width c of the protruding portion 4c is 1.2 mm, and the protruding portion 4b and the protruding portion 4b are protruded. Part 4
The minimum distance A from c is set to 3.5 mm, and "a
The relationship “≦ A ≦ (a + b + c)” is satisfied.

As described above, in the liquid crystal display device according to the first embodiment, the step portion that prevents the liquid crystal sealing member from entering the display region is provided in the injection path, and "a≤A≤ (a +
b + c) ”relationship is satisfied. Therefore, when the liquid crystal display device according to the first embodiment is used, unlike the conventional liquid crystal display device, due to the action of the stepped portion and the action of satisfying the relationship of “a ≦ A ≦ (a + b + c)”, It is possible to prevent the stop member from entering the display area, and as a result, it is possible to suppress display unevenness.

As described above, according to the liquid crystal display device of the first embodiment, since the liquid crystal sealing member can be prevented from entering the display area, the frame can be made narrower than the conventional one. Therefore, in the first embodiment, the step portion 13
The distance B from the (step surface) to the inlet end of the injection path 12 is 1.
It can be 5 mm or less.

(Second Embodiment) Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view of the liquid crystal display device according to the second embodiment of the present invention taken along the thickness direction.

As shown in FIG. 3, the liquid crystal display device according to the second embodiment also has a liquid crystal drive substrate 21, a counter substrate 22, and a seal member 24, as in the first embodiment. These are the same as those used in the first embodiment. In FIG. 3, 30 is a liquid crystal sealing member, 3 is
2 is an injection path, and 33 is a stepped portion.

Further, a first protective film 25 and a first alignment film 26 are sequentially provided on the facing surface of the liquid crystal drive substrate 21,
A second protective film 27, a common electrode 28, and an alignment film 29 are sequentially provided on the facing surface of the counter substrate 22. The thickness of each film is set within the same range as in the first embodiment.

However, in the second embodiment, the step portion 33 in the counter substrate 22 is formed by the second protective film 27 and the common electrode 28, which is different from the first embodiment in this respect. . Therefore, in the second embodiment,
The height of the step portion 33 on the counter substrate 22 is the sum of the thickness of the second protective film 27 and the thickness of the common electrode 28, and is higher than that in the first embodiment by using two types of films. There is. Therefore, it can be said that the effect of the step portion 33 can be enhanced by using the liquid crystal display device according to the second embodiment.

Further, in the second embodiment, the opening length a
Is 6 mm, the minimum width b of one protrusion is 1.0 mm, the minimum width c of the other protrusion is 0.8 mm, and the minimum distance A between one protrusion and the other protrusion is set to 7.5 mm. ing. Therefore, also in the second embodiment, “a ≦ A ≦
The relationship “a + b + c” is satisfied. Also, the step portion 33
The distance B from the (step surface) to the inlet end of the injection path 32 is 0.
It is 5 mm.

As described above, also in the liquid crystal display device according to the second embodiment, the step portion that prevents the liquid crystal sealing member from entering the display region is provided in the injection path, and "a≤A≤.
Since the relationship of “(a + b + c)” is satisfied, it is possible to prevent the liquid crystal sealing member from entering the display area and prevent display unevenness from occurring. Further, in the second embodiment, since the height of the step portion is higher than that in the first embodiment, the intrusion of the liquid crystal sealing member can be further suppressed.

(Third Embodiment) Next, a liquid crystal display device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the liquid crystal display device according to the third embodiment of the present invention taken along the thickness direction.

As shown in FIG. 4, the liquid crystal display device according to the third embodiment also has a liquid crystal drive substrate 41, a counter substrate 42, and a seal member 44, as in the first embodiment. These are the same as those used in the first embodiment. In FIG. 3, reference numeral 50 denotes a liquid crystal sealing member, 5
2 is an injection path, and 53 is a stepped portion.

Further, a first protective film 45 and a first alignment film 46 are sequentially provided on the facing surface of the liquid crystal drive substrate 41,
A second protective film 47, a common electrode 48, and an alignment film 49 are sequentially provided on the facing surface of the counter substrate 42. The thickness of each film is set within the same range as in the first embodiment.

Further, also in the third embodiment, the step portion 53 is provided in the injection passage 52. However, in the third embodiment, the step portion 53 in the liquid crystal drive substrate 41 is formed by the first alignment film 46, and the step portion 53 in the counter substrate 42 is formed by the common electrode 48 and the second alignment film 49. It is different from the first and second embodiments in that it is formed.

In the third embodiment, the opening length a is 10
mm, the minimum width b of one protrusion is 0.8 mm, the minimum width c of the other protrusion is 0.8 mm, and the minimum distance A between one protrusion and the other protrusion is set to 11.0 mm. There is.
Therefore, also in the second embodiment, “a ≦ A ≦ (a
+ B + c) ”is satisfied. In addition, the step portion 53
The distance B from the (step surface) to the inlet end of the injection path 52 is 1.
It is 2 mm.

As described above, also in the liquid crystal display device according to the second embodiment, the step portion that prevents the liquid crystal sealing member from entering the display region is provided in the injection path, and "a≤A≤.
Since the relationship of “(a + b + c)” is satisfied, it is possible to prevent the liquid crystal sealing member from entering the display area and prevent display unevenness from occurring.

[0044]

As described above, according to the liquid crystal display device of the present invention, it is possible to prevent the liquid crystal sealing member for sealing the injection port from entering the display area, and display unevenness is achieved. Can be suppressed. This also allows
The defect rate can be reduced, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view of the liquid crystal display device according to the first embodiment of the present invention taken along the thickness direction, FIG. 1 (b).
Is a cross-sectional view taken along the cutting line AA ′ in FIG.

FIG. 2 is an enlarged cross-sectional view showing an injection path shown in FIG. 1 (b).

FIG. 3 is a cross-sectional view of the liquid crystal display device according to the second embodiment of the present invention taken along the thickness direction.

FIG. 4 is a cross-sectional view of the liquid crystal display device according to the third embodiment of the present invention taken along the thickness direction.

5 (a) is a cross-sectional view of a conventional liquid crystal display device taken along the thickness direction, and FIG. 5 (b) is a cutting line B in FIG. 5 (a).
-B 'cross-section view

[Explanation of symbols]

1, 21, 41 Liquid crystal drive substrate 2, 21, 22 Counter substrate 3,23,43 liquid crystal 4, 24, 44 Seal member 5, 25, 45 First protective film 6, 26, 46 First alignment film 7, 27, 47 Second protective film 8, 28, 48 common electrode 9, 29, 49 Second alignment film 10, 30, 50 Liquid crystal sealing member 11 openings 12, 32, 52 injection path 13, 33, 53 Steps

Claims (13)

[Claims] 1. A liquid crystal driving substrate, a counter substrate facing the liquid crystal driving substrate, and a seal member sandwiched between the two substrates to form a space filled with liquid crystal, the seal member comprising:
A frame-shaped portion formed in a frame shape having an opening, and a pair of protrusions protruding from both ends of the opening to the outside of the frame-shaped portion, the protrusion is the two substrates, A liquid crystal display device having an injection path for injecting the liquid crystal to the inside of the frame-shaped portion, wherein at least one of the two substrates is within a region where the protrusion and the injection path are formed. A step portion, and the step portion has a distance between the two substrates on the inlet side of the injection path with respect to the step portion, and a distance between the two substrates on the outlet side of the injection path. The opening length of the opening is a, the minimum width of the one protruding portion measured in parallel with the opening surface of the opening is b, and the minimum width of the protrusion is measured in parallel with the opening surface of the opening. The minimum width of the other protruding portion is c, which is on the inlet side of the injection path of the step portion. That one of the minimum distance between the protruding portion and the other projecting portion is taken as A, a
A liquid crystal display device, wherein the relationship of ≦ A ≦ (a + b + c) is satisfied. 2. The liquid crystal display device according to claim 1, wherein a distance from the step portion to an inlet-side end portion of the injection path is 0.1 mm or more and 1.5 mm or less. 3. A first protective film and a first alignment film are sequentially provided on a surface of the liquid crystal driving substrate facing the counter substrate, and a second protective film and a first alignment film are provided on a surface of the counter substrate facing the liquid crystal driving substrate. The liquid crystal display device according to claim 1, wherein a protective film, a common electrode, and a second alignment film are sequentially provided. 4. The liquid crystal display device according to claim 3, wherein an end portion of the first protective film is located in the injection path, and the step is formed by the end portion of the first protective film. . 5. The liquid crystal display device according to claim 4, wherein the thickness of the first protective film is 0.1 μm or more and 20 μm or less. 6. The liquid crystal display device according to claim 3, wherein an end portion of the second protective film is located in the injection path, and the step is formed by the end portion of the second protective film. . 7. The liquid crystal display device according to claim 6, wherein the thickness of the second protective film is 0.1 μm or more and 20 μm or less. 8. The liquid crystal display device according to claim 3, wherein an end of the common electrode is located in the injection path, and the step is formed by the end of the common electrode. 9. The liquid crystal display device according to claim 8, wherein the common electrode has a thickness of 0.05 μm or more and 0.5 μm or less. 10. The liquid crystal display device according to claim 3, wherein an end of the first alignment film is located in the injection path, and the step is formed by the end of the first alignment film. . 11. The thickness of the first alignment film is 0.05 μm.
The liquid crystal display device according to claim 10, wherein the liquid crystal display device has a thickness of not less than m and not more than 0.5 μm. 12. The liquid crystal display device according to claim 3, wherein an end portion of the second alignment film is located in the injection path, and the step is formed by the end portion of the second alignment film. . 13. The second alignment film has a thickness of 0.05 μm.
The liquid crystal display device according to claim 12, having a thickness of not less than m and not more than 0.5 μm.