JP2013076852A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the occurrence rate of minute bright spots by preventing displacement of substrates.SOLUTION: A liquid crystal display device includes: a spacer 80 holding a gap between a first substrate 28 and a second substrate 36; a foundation layer 40 having a recess 66 on the side of a second alignment film 22; and a liquid crystal layer 26 interposed between a first surface 20 of a first alignment film 18 and a second surface 24 of the second alignment film 22 which face each other. The first alignment film 18 has a first projecting portion 82 where the first surface 20 projects, along the shape of the spacer 80, and a bottom surface of the recess 66 of the foundation layer 40 is made rugged, and a recess 84 is formed in the second surface 24 of the second alignment film 22 correspondingly to the shape of the foundation layer 40, and a bottom surface of the recess 84 of the second alignment film 22 is made rugged due to a second projection 76 lower than the second surface 24 of the second alignment film 22 and a recess 78 having a bottom surface lower than the second projection 76, and the first projection 82 of the first alignment film 18 is in the recess 84 of the second alignment film 22 to come into contact with the second projection 76.

Description

  The present invention relates to a liquid crystal display device.

  In medium- and large-sized liquid crystal display devices of the 17-inch class or higher, there are problems of wiping unevenness and minute bright spots due to alignment film scraping that occur during vibration tests. Wiping unevenness is a phenomenon in which when the surface of a liquid crystal display panel is touched, a gap is partially changed due to a shift between a TFT (Thin Film Transistor) substrate and a color filter substrate, which is recognized as unevenness. In addition, in medium and large liquid crystal display devices, the load applied to the liquid crystal display panel when subjected to vibration or impact increases. For this reason, the TFT substrate and the color filter substrate are rubbed to cause scraping of the alignment film, and defects caused by disturbing the alignment are minute bright spots.

  As a measure against uneven wiping, the sealing pressure is weakened so that the TFT substrate and the color filter substrate can be easily returned to each other even when they are displaced. However, if the sealing pressurization is too weak, the peripheral gap widens in a high temperature environment, so that the portion turns yellow and high temperature gap unevenness occurs.

JP 2011-22535 A

  Patent Document 1 discloses that a recess is formed in a region facing the spacer, and the spacer is inserted into the recess to prevent the TFT substrate and the color filter substrate from being displaced. Therefore, the generation of minute bright spots is reduced by reducing the displacement of the spacer. However, since the alignment film cannot be completely scraped, it is difficult to prevent the shavings from floating.

  An object of the present invention is to prevent the substrate from shifting and to reduce the incidence of minute bright spots.

  (1) A liquid crystal display device according to the present invention includes a first substrate, a second substrate disposed to face the first substrate with a space therebetween, and a first alignment film formed on the first substrate. And a second alignment film formed on the second substrate, a spacer formed between the first substrate and the first alignment film, and holding a gap between the first substrate and the second substrate; An underlayer formed between the second substrate and the second alignment film and having a depression on the second alignment film side, the first surface of the first alignment film and the second alignment facing each other. A liquid crystal layer sandwiched between the second surfaces of the film, and the first alignment film has a first protrusion protruding from the first surface along the shape of the spacer, and the base layer The bottom surface of the recess is formed in a concavo-convex shape, and a recess is formed on the second surface of the second alignment film corresponding to the shape of the underlayer. The depression of the second alignment film is formed in a concavo-convex shape by a second convex portion lower than the second surface of the second alignment film and a concave portion having a bottom surface lower than the second convex portion. The first convex portion of the first alignment film enters the dent of the second alignment film and is in contact with the second convex portion. According to the present invention, the first convex portion of the first alignment film corresponding to the spacer enters the recess of the second alignment film, thereby preventing the first substrate and the second substrate from being displaced. Furthermore, since the depression of the second alignment film is uneven at the second protrusion and the recess, the shavings of the first alignment film and the second alignment film accumulate in the recess. Thereby, floating of the shavings can be prevented and the generation rate of minute bright spots can be reduced.

  (2) In the liquid crystal display device described in (1), a part of the first convex portion of the first alignment film protrudes from the second convex portion, and a gap is formed from the bottom surface of the concave portion. It may be characterized by being located.

  (3) In the liquid crystal display device described in (2), the first convex portion of the first alignment film faces the entire second convex portion and is larger than the second convex portion. It is good.

  (4) In the liquid crystal display device described in any one of (1) to (3), the concave portion of the second alignment film may include the first convex portion so that the first convex portion does not enter. It may be characterized by being smaller than.

  (5) In the liquid crystal display device according to any one of (1) to (4), the second convex portion of the second alignment film is a part of the inner wall of the recess of the second alignment film. A plurality of the recesses may be formed so as to be partitioned by the second protrusions in the recess of the second alignment film.

  (6) In the liquid crystal display device described in any one of (1) to (4), the concave portion may be formed so as to surround the second convex portion.

  (7) In the liquid crystal display device described in any one of (1) to (4), the concave portion may be formed inside and outside the second convex portion.

  (8) In the liquid crystal display device described in any one of (1) to (7), the base layer applies a voltage to the liquid crystal layer and a semiconductor layer and a plurality of wirings for forming a thin film transistor. And an insulating layer between the thin film transistor and the electrode, and the recess of the base layer is formed by a hole in the insulating layer.

  (9) In the liquid crystal display device described in (8), the insulating layer includes a first inorganic insulating film that covers the thin film transistor, an organic insulating film that covers the first inorganic insulating film, and the first inorganic insulating film. And a second inorganic insulating film covering the organic insulating film.

  (10) In the liquid crystal display device described in (9), the hole of the insulating layer is formed by a through hole of the first inorganic insulating film and a through hole of the organic insulating film, and the first inorganic insulating film The through hole is formed to be smaller than the through hole of the organic insulating film, and the depression of the base layer is formed by a part of the first inorganic insulating film located inside the through hole of the organic insulating film. A convex portion is formed on the bottom surface of the first inorganic insulating film, and the second inorganic insulating film includes the through hole of the first inorganic insulating film, the through hole of the organic insulating film, and a part of the first inorganic insulating film. It is good also as being formed in unevenness on the 1st inorganic insulating film and the organic insulating film so that the convex part may be covered.

  (11) In the liquid crystal display device according to (9), the hole of the insulating layer is formed by a through hole of the organic insulating film, and is inside the through hole of the organic insulating film, and is the first hole. Under the inorganic insulating film, a first layer made of the same material as the semiconductor layer and a second layer made of the same material as the plurality of wirings are laminated in a convex shape, and the first inorganic insulating film The first inorganic insulating film is formed to cover the first layer and the second layer, and the second inorganic insulating film covers the through hole of the organic insulating film and the convex part of the first inorganic insulating film. In addition, it may be formed in an uneven shape on the first inorganic insulating film and the organic insulating film.

1 is an exploded perspective view showing a liquid crystal display device according to a first embodiment to which the present invention is applied. It is a partial cross section figure of a liquid crystal display panel. FIG. 3 is a partial cross-sectional view of a liquid crystal display panel at a position different from that in FIG. 2. It is a top view which shows the hollow of a 2nd alignment film. It is a partial cross section figure of the liquid crystal display panel which concerns on 2nd Embodiment. It is a top view of the 1st layer and the 2nd layer. It is a top view which shows an example of the shape of a 1st convex part and a 2nd convex part. It is a top view which shows an example of the shape of a 1st convex part and a 2nd convex part. It is a top view which shows an example of the shape of a 1st convex part and a 2nd convex part. It is a top view which shows an example of the shape of a 1st convex part and a 2nd convex part. It is a top view which shows an example of the shape of a 1st convex part and a 2nd convex part. It is a top view which shows an example of the shape of a 1st convex part and a 2nd convex part. It is a top view which shows an example of the shape of the hollow of a 2nd alignment film.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is an exploded perspective view showing a liquid crystal display device according to a first embodiment to which the present invention is applied. The liquid crystal display device includes a liquid crystal display panel 10. A flexible wiring board 12 is attached to the liquid crystal display panel 10, and polarizing plates 14 are attached to both sides. The liquid crystal display device includes a backlight 16 so that a bright image can be displayed.

  FIG. 2 is a partial cross-sectional view of the liquid crystal display panel 10. FIG. 3 is a partial cross-sectional view of the liquid crystal display panel 10 at a position different from that in FIG. The liquid crystal display panel 10 includes a liquid crystal layer 26 sandwiched between the first surface 20 of the first alignment film 18 and the second surface 24 of the second alignment film 22.

  The liquid crystal display panel 10 includes a first substrate 28 made of a light transmissive substrate such as a glass substrate. The first substrate 28 constitutes a color filter substrate, and a black matrix layer 30 and a colored layer 32 are laminated. In order to flatten the unevenness on the surface of the colored layer 32, a flattened layer 34 is formed on the colored layer 32 on the side opposite to the black matrix layer 30. A first alignment film 18 is formed on the planarization layer 34.

  The liquid crystal display panel 10 includes a second substrate 36 made of a light transmissive substrate such as a glass substrate. As shown in FIG. 3, the second substrate 36 is formed with a thin film transistor 38 and is called a TFT substrate. The second substrate 36 is disposed so as to face the first substrate 28 with a space therebetween. A second alignment film 22 is formed on the second substrate 36. A base layer 40 is formed between the second substrate 36 and the second alignment film 22. The underlayer 40 is configured by laminating various layers as described below.

  A gate wiring 42 is formed on the second substrate 36. A gate insulating film 44 is formed so as to cover the gate wiring 42, and a semiconductor layer 46 (for example, an amorphous silicon layer) is formed on the gate insulating film 44 above the gate wiring 42. A source wiring 48 and a drain wiring 50 are formed on the semiconductor layer 46 with a space therebetween. A first inorganic insulating film 52 is formed so as to cover the thin film transistor 38 (the semiconductor layer 46, the gate wiring 42, the source wiring 48, and the drain wiring 50).

  An organic insulating film 54 made of resin or the like is formed so as to cover the first inorganic insulating film 52. A second inorganic insulating film 56 is formed so as to cover the first inorganic insulating film 52 and the organic insulating film 54. On the second inorganic insulating film 56, an electrode 58 (for example, a transparent electrode made of ITO (Indium Tin Oxide)) for applying a voltage to the liquid crystal layer 26 is formed. Under the electrode 58, a wiring 60 made of metal is formed. Note that the electrode 58 is a common electrode, and a plurality of pixel electrodes are formed at positions not shown in the drawing. A second alignment film 22 is formed so as to cover the electrode 58.

  The underlayer 40 includes a semiconductor layer 46 and a plurality of wirings 62 (gate wiring 42, source wiring 48 and drain wiring 50) for forming the thin film transistor 38, an electrode 58 for applying a voltage to the liquid crystal layer 26, and a thin film transistor 38 and the insulating layer 64 (the first inorganic insulating film 52, the organic insulating film 54, and the second inorganic insulating film 56) between the electrode 38 and the electrode 58.

  As shown in FIG. 2, the underlayer 40 has a depression 66 on the second alignment film 22 side. The bottom surface of the recess 66 of the foundation layer 40 is formed in an uneven shape. The depression 66 of the base layer 40 is formed by a hole 68 in the insulating layer 64 including the first inorganic insulating film 52, the organic insulating film 54, and the second inorganic insulating film 56. Specifically, the hole 68 of the insulating layer 64 shown in FIG. 2 is formed by the through hole 70 of the first inorganic insulating film 52 and the through hole 72 of the organic insulating film 54.

  A part of the first inorganic insulating film 52 remains inside the through hole 72 of the organic insulating film 54. Therefore, the through hole 70 of the first inorganic insulating film 52 is formed smaller than the through hole 72 of the organic insulating film 54. A convex portion 74 is formed on the bottom surface of the recess 66 of the base layer 40 by a part of the first inorganic insulating film 52 located inside the through hole 72 of the organic insulating film 54.

  The second inorganic insulating film 56 covers the through hole 70 of the first inorganic insulating film 52, the through hole 72 of the organic insulating film 54, and the convex portion 74 made of a part of the first inorganic insulating film 52. Thereby, the second inorganic insulating film 56 is uneven due to the through holes 70 and 72 and the protrusion 74.

  FIG. 4 is a plan view showing the depression 84 of the second alignment film 22. A recess 84 is formed in the second surface 24 of the second alignment film 22 corresponding to the shape of the underlayer 40. The depression 84 of the second alignment film 22 is formed in an uneven shape. Specifically, a second protrusion 76 that is lower than the second surface 24 of the second alignment film 22 is formed in the recess 84. The second protrusion 76 of the second alignment film 22 extends from a part of the inner wall of the recess 84 of the second alignment film 22 to another part (see FIG. 4). A recess 78 having a bottom surface lower than the second protrusion 76 is formed in the recess 84. A plurality of recesses 78 are formed in the recesses 84 of the second alignment film 22 so as to be partitioned by the second protrusions 76.

  As shown in FIG. 2, the gap between the first substrate 28 and the second substrate 36 is held by a spacer 80 made of resin or the like. The spacer 80 is formed between the first substrate 28 and the first alignment film 18. The first alignment film 18 has a first protrusion 82 from which the first surface 20 protrudes along the shape of the spacer 80. The first protrusion 82 of the first alignment film 18 enters the recess 84 of the second alignment film 22 and is in contact with the second protrusion 76. A part of the first convex portion 82 of the first alignment film 18 protrudes from the second convex portion 76 and is positioned with a gap from the bottom surface of the concave portion 78. The concave portion 78 of the second alignment film 22 is smaller than the first convex portion 82 so that the first convex portion 82 does not enter. That is, the width of the concave portion 78 is smaller than the width of the first convex portion 82.

  According to the present embodiment, the first protrusion 82 of the first alignment film 18 corresponding to the spacer 80 enters the recess 84 of the second alignment film 22, thereby preventing the first substrate 28 and the second substrate 36 from being displaced. can do. Further, since the depression 84 of the second alignment film 22 is uneven by the second protrusion 76 and the recess 78, the shavings of the first alignment film 18 and the second alignment film 22 are accumulated in the recess 78. It has become. Thereby, floating of the shavings can be prevented and the generation rate of minute bright spots can be reduced.

[Second Embodiment]
FIG. 5 is a partial cross-sectional view of the liquid crystal display panel 10 according to the second embodiment. In this example, the hole 168 in the insulating layer 164 is formed by the through hole 172 in the organic insulating film 154. Under the first inorganic insulating film 152, a first layer 184 made of the same material as the semiconductor layer 46 (see FIG. 3) and a second layer 186 made of the same material as the plurality of wirings 62 (see FIG. 3). They are stacked in a convex shape. The first layer 184 and the second layer 186 are formed inside the through hole 172 of the organic insulating film 154.

  FIG. 6 is a plan view of the first layer 184 and the second layer 186, and shows an example in which the first layer 184 and the second layer 186 form a cross. Since the first layer 184 and the second layer 186 have a convex shape, the first inorganic insulating film 152 covering the first layer 184 and the second layer 186 also has a convex portion 174. The second inorganic insulating film 156 is formed in an uneven shape on the first inorganic insulating film 152 and the organic insulating film 154 so as to cover the through hole 172 of the organic insulating film 154 and the convex portion 174 of the first inorganic insulating film 152. Has been. The other configurations correspond to the contents described in the first embodiment.

[Modification]
7 to 13 are plan views showing various shapes of the depressions or the second protrusions of the second alignment film.

  In the example shown in FIG. 7, the planar shape of the first convex portion 282 of the first alignment film is circular, and the planar shape of the second convex portion 276 of the second alignment film is a cross. The first convex portion 282 is disposed so as to face (mount) the cross-shaped intersection 288 of the second convex portion 276 and the portion 290 extending in four directions from the intersection 288.

  In the example shown in FIG. 8, the planar shape of the first convex portion 382 of the first alignment film is circular, and the planar shape of the second convex portion 376 of the second alignment film includes a plurality of strip-shaped portions 392. ing. In the arrangement direction of the plurality of strip-shaped portions 392 of the second convex portion 376, the first convex portion 382 is opposed to the strip-shaped portion 392a excluding both ends over the entire width direction. On the other hand, the first convex portions 382 are opposed to the side ends of the band-like portions 392b located at both ends in the arrangement direction, respectively, but are opposite to each other. The convex part 382 does not oppose.

  In the example illustrated in FIG. 9, the first convex portion 482 of the first alignment film faces the entire second convex portion 476 and is larger than the second convex portion 476. The recess 478 of the second alignment film recess 484 is formed so as to surround the second protrusion 476. The planar shape of the first convex portion 482 of the first alignment film is circular, and the planar shape of the second convex portion 476 of the second alignment film is also circular.

  In the example shown in FIG. 10, the planar shape of the second convex portion 576 of the second alignment film is rectangular, and the other configuration is the same as the example of FIG.

  In the example shown in FIG. 11, the recesses 678 of the recesses 684 of the second alignment film are formed inside and outside the second protrusions 676. The planar shape of the second convex portion 676 is a ring shape. The other configuration is the same as the example of FIG. According to the example of FIG. 11, the recesses 678 of the recesses 684 of the second alignment film are formed inside and outside the second protrusions 676. Therefore, when the scraps of the first alignment film and the second alignment film enter the concave portion 678 inside the second convex portion 676, the upper portion is blocked by the first convex portion 682 and thus does not go out. Therefore, floating of the shavings can be prevented.

  In the example shown in FIG. 12, the planar shape of the first convex portion 782 of the first alignment film is circular, and the planar shape of the second convex portion 776 of the second alignment film is # shape. The first convex part 782 is arranged so as to oppose (mount) the four crossing parts 794 of the # shape of the second convex part 776 and the portion 796 extending from the intersecting part 794 in four directions. The recesses 778 of the second alignment film recesses 784 are formed inside (# -shaped central region) and outside of the second protrusions 776. The effect corresponds to the content described above for the example shown in FIG.

  FIG. 13 is a diagram illustrating an example in which the planar shape of the depression 884 of the second alignment film is rectangular. Other structures are the same as those shown in FIG.

  The present invention is not limited to the embodiment described above, and various modifications are possible. For example, the configuration described in the embodiment can be replaced with a substantially the same configuration, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose.

  DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel, 12 Flexible wiring board, 14 Polarizing plate, 16 Backlight, 18 1st alignment film, 20 1st surface, 22 2nd alignment film, 24 2nd surface, 26 Liquid crystal layer, 28 1st substrate, 30 Black matrix layer, 32 colored layer, 34 planarization layer, 36 second substrate, 38 thin film transistor, 40 underlayer, 42 gate wiring, 44 gate insulating film, 46 semiconductor layer, 48 source wiring, 50 drain wiring, 52 first inorganic Insulating film, 54 Organic insulating film, 56 Second inorganic insulating film, 58 electrode, 60 wiring, 62 multiple wirings, 64 insulating layer, 66 depression, 68 hole, 70 through hole, 72 through hole, 74 convex part, 76 first 2 convex portions, 78 concave portions, 80 spacers, 82 first convex portions, 84 depressions, 152 first inorganic insulating film, 154 organic insulating film, 156 second inorganic Insulating film, 164 insulating layer, 168 hole, 172 through-hole, 174 convex part, 184 first layer, 186 second layer, 276 second convex part, 282 first convex part, 288 crossing part, 290 second convex part Part, 376 second convex part, 382 first convex part, 392 strip-shaped part, 476 second convex part, 478 concave part, 482 first convex part, 484 hollow, 576 second convex part, 684 second convex part, 678 concave part , 682 1st convex part, 784 2nd convex part, 778 Concave part, 782 1st convex part, 794 Crossing part, 796 2nd convex part part, 884 The depression of the 2nd alignment film.

Claims (11)

A first substrate;
A second substrate disposed to face the first substrate with a space therebetween;
A first alignment film formed on the first substrate;
A second alignment film formed on the second substrate;
A spacer formed between the first substrate and the first alignment film, and holding a gap between the first substrate and the second substrate;
An underlayer formed between the second substrate and the second alignment film, and having a depression on the second alignment film side;
A liquid crystal layer sandwiched between a first surface of the first alignment film and a second surface of the second alignment film facing each other;
Have
The first alignment film has a first convex part from which the first surface protrudes along the shape of the spacer,
The bottom surface of the recess of the base layer is formed in an uneven shape,
A depression is formed on the second surface of the second alignment film corresponding to the shape of the underlayer,
The recess of the second alignment film is formed in a concavo-convex shape by a second convex portion lower than the second surface of the second alignment film and a concave portion having a bottom surface lower than the second convex portion,
The liquid crystal display device, wherein the first convex portion of the first alignment film enters the depression of the second alignment film and is in contact with the second convex portion. The liquid crystal display device according to claim 1,
A part of the first convex portion of the first alignment film protrudes from the second convex portion and is located with a gap from the bottom surface of the concave portion. The liquid crystal display device according to claim 2,
The liquid crystal display device according to claim 1, wherein the first convex portion of the first alignment film faces the entire second convex portion and is larger than the second convex portion. In the liquid crystal display device according to any one of claims 1 to 3,
The liquid crystal display device, wherein the concave portion of the second alignment film is smaller than the first convex portion so that the first convex portion does not enter. The liquid crystal display device according to any one of claims 1 to 4,
The second convex portion of the second alignment film extends from a part of the inner wall of the recess of the second alignment film to another part,
A plurality of the concave portions are formed in the depression of the second alignment film so as to be partitioned by the second convex portions. The liquid crystal display device according to any one of claims 1 to 4,
The liquid crystal display device, wherein the concave portion is formed so as to surround the second convex portion. The liquid crystal display device according to any one of claims 1 to 4,
The liquid crystal display device, wherein the concave portion is formed inside and outside the second convex portion. The liquid crystal display device according to any one of claims 1 to 7,
The underlayer includes a semiconductor layer and a plurality of wirings for forming a thin film transistor, an electrode for applying a voltage to the liquid crystal layer, and an insulating layer between the thin film transistor and the electrode,
The liquid crystal display device, wherein the recess of the base layer is formed by a hole in the insulating layer. The liquid crystal display device according to claim 8, wherein
The insulating layer includes a first inorganic insulating film that covers the thin film transistor, an organic insulating film that covers the first inorganic insulating film, and a second inorganic insulating film that covers the first inorganic insulating film and the organic insulating film. A liquid crystal display device comprising: The liquid crystal display device according to claim 9,
The hole of the insulating layer is formed by a through hole of the first inorganic insulating film and a through hole of the organic insulating film,
The through hole of the first inorganic insulating film is formed smaller than the through hole of the organic insulating film;
A convex portion is formed on the bottom surface of the recess of the base layer by a part of the first inorganic insulating film located inside the through hole of the organic insulating film,
The second inorganic insulating film covers the through hole of the first inorganic insulating film, the through hole of the organic insulating film, and the convex portion formed of a part of the first inorganic insulating film. 1. A liquid crystal display device, wherein the liquid crystal display device is formed in an uneven shape on an inorganic insulating film and the organic insulating film. The liquid crystal display device according to claim 9,
The hole of the insulating layer is formed by a through hole of the organic insulating film,
A first layer made of the same material as the semiconductor layer, and a second layer made of the same material as the plurality of wirings, inside the through hole of the organic insulating film and below the first inorganic insulating film; Are stacked in a convex shape,
The first inorganic insulating film is formed to have a convex portion by covering the first layer and the second layer,
The second inorganic insulating film is formed in an uneven shape on the first inorganic insulating film and the organic insulating film so as to cover the through hole of the organic insulating film and the convex portion of the first inorganic insulating film. A liquid crystal display device.

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