JP4102915B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bonding structure of a pair of substrates constituting a liquid crystal display device.
[0002]
[Prior art]
FIG. 9 shows a plan view of an example of a conventional liquid crystal display device. In this liquid crystal display device, a common glass substrate 2 is laminated on a segment glass substrate 1 in FIG. 9 with a substantially rectangular frame-shaped sealing material 3 therebetween, and both glass substrates 1 inside the sealing material 3 are bonded. The liquid crystal 4 (see FIG. 11) is sealed between the two. Each of the opposing surfaces (hereinafter referred to as inner surfaces) of the glass substrates 1 and 2 is formed with a plurality of segment electrodes and common electrodes, which will be described later, extending in directions orthogonal to each other, A plurality of pixels are arranged in a matrix. In this case, a rectangular area surrounded by a one-dot chain line inside the sealing material 3 is a display area 5 in which pixels are arranged in a matrix, and the outside thereof is a non-display area 6 in which no pixels exist. . Further, a protruding portion 1 a protruding from the common glass substrate 2 is formed on the lower side of the segment glass substrate 1 in FIG. 9. Although not shown, a plurality of connection terminals (segment terminals and common terminals) connected to the segment electrode and the common electrode are provided on the upper surface of the projecting portion 1a.
[0003]
Next, FIG. 10 shows an enlarged plan view of a part of the liquid crystal display device shown in FIG. 9, and FIG. 11 shows a cross-sectional view taken along line YY of FIG. The inner surface of the segment glass substrate 1 (the surface facing the common glass substrate 2) is a black matrix 11 made of a light-shielding metal such as chrome, red, green and blue color filter elements 12R, 12G, 12B made of colored resin, acrylic A planarizing film 13 made of resin or the like, a segment electrode 14 made of a transparent conductor such as ITO, and an alignment film 15 made of a polyimide material are laminated in this order.
[0004]
In this case, the color filter elements 12R, 12G, and 12B are provided only in the display area 5. The black matrix 11 is provided in a lattice shape at the boundary between the color filter elements 12R, 12G, and 12B in the display area 5, and is provided in a rectangular frame shape in the non-display area 6. Both the black matrix 11 and the planarizing film 13 are provided to the vicinity of the end face of the segment glass substrate 1 in order to make the gap uniform. The segment electrode 14 is provided so as to extend in the lateral direction of the substrate in FIGS. 9 and 10. As shown in FIG. 11, for example, the right end portion of the segment electrode 14 extends to the non-display region 6 and is provided to the vicinity of the end surface of the planarizing film 13 in order to make the gap uniform. Yes. The alignment film 15 is provided inside the sealing material 3.
[0005]
On the other hand, a common electrode 16 made of a transparent conductor such as ITO and an alignment film 17 made of a polyimide material are laminated in this order on the inner surface of the common glass substrate 2 (the surface facing the segment glass substrate 1). In this case, the common electrode 16 is provided so as to extend in the longitudinal direction of the substrate in FIGS. 9 and 10. Further, the common electrode 16 is also provided in the non-display area 6 on the right side of FIG. 11, for example, in order to make the gap uniform. The alignment film 17 is provided inside the sealing material 3. The sealing material 3 is interposed between the planarizing film 13 having the segment electrode 14 on the surface and the common glass substrate 2 having the common electrode 16 on the surface.
[0006]
Next, another example of a conventional liquid crystal display device will be described with reference to FIG. 12, which is a cross-sectional view similar to FIG. In this case, the black matrix 11 ′ is formed by stacking red, green, and blue color filter elements 12R, 12G, and 12B. In this case as well, the peripheral edge of the black matrix 11 ′ is provided to the vicinity of the end surface of the segment glass substrate 1 in order to make the gap uniform.
[0007]
[Problems to be solved by the invention]
By the way, in the case of the liquid crystal display device shown in FIG. 11, the substrates facing each other are joined by a sealing material via chromium, a planarizing film, and a transparent electrode, and the adhesion between the members is such as chromium or the like. Since the black matrix 11 made of a light-shielding metal and the planarizing film 13 made of a resin material such as an acrylic resin are relatively bad, peeling between the two tends to occur. There was a problem that the bonding strength between the two was low. On the other hand, in the case of the liquid crystal display device shown in FIG. 12, the black matrix 11 ′ is configured by stacking red, green, and blue color filter elements 12 R, 12 G, and 12 B made of colored resin. There was a problem that green and blue color filter elements 12R, 12G, and 12B had relatively poor adhesion to each other, and peeling was likely to occur between them. By the way, when the adhesion strength between the glass substrates 1 and 2 of the liquid crystal display device obtained by directly bonding the glass substrates 1 and 2 with the sealing material 3 without the black matrix 11 or the flattening film 13 is 1, In the case of the liquid crystal display device shown in FIG. 11 and FIG. 12, it becomes considerably weak at about 0.2 to 0.4.
An object of the present invention is to provide a liquid crystal display device in which a desired gap between two glass substrates in a liquid crystal display device is uniformly ensured and the bonding strength between the two glass substrates is high. .
[0008]
[Means for Solving the Problems]
According to the liquid crystal display device of the present invention, the black matrix, the planarizing film, and the electrode are laminated in this order on one of the mutually facing inner surfaces of the pair of substrates arranged opposite to each other. In the liquid crystal display device, the pair of substrates are joined by a substantially rectangular frame-shaped sealing material formed surrounding the region where the black matrix, the planarization film, and the electrode are formed on the one inner surface. The black matrix laminated on the one inner surface extends to a position where the peripheral edge of the black matrix penetrates to the middle of the width of the sealing material, and the planarizing film includes a display area and a non-display area of the liquid crystal display device. Having a film thickness for substantially equalizing the gap between the opposing substrates, and extending to a position overlapping the entire width of the sealing material covering the peripheral edge of the black matrix, Serial respectively formed by extending until overlapping the sealing material on the planarization layer, wherein that part of the peripheral portion of the planarizing film in close contact in direct contact with said one inner surface in the region overlapping with the sealing material It is characterized by.
According to the present invention, since the black matrix and the flattening film are extended to the region where the sealing material is provided, the desired gap can be secured uniformly and the flattening film provided to overlap the black matrix. Since at least a part of the peripheral edge and / or the sealing material is directly laminated and fixed on the inner surface of the glass substrate, the inner surface of the glass substrate is flattened even if the adhesion strength between the flattening film and the black matrix is weak. Since the adhesion strength between the film and the sealing material is relatively strong, peeling between the two glass substrates bonded together can be effectively prevented, and the bonding strength between the two glass substrates can be increased.
In this case, it is preferable that the corner portion of the peripheral portion of the planarization film is in direct contact with and closely contacts the one inner surface as in the invention described in claim 2.
In addition, as in the invention described in claim 3, it is preferable that the edge of the planarization film is in direct contact with and closely contacts the inner surface of the entire flattening film.
According to a fourth aspect of the present invention, it is preferable that the electrode is interposed between the sealing material and the planarizing film over the entire width of the sealing material . In this case, as in the invention described in claim 5, it is more preferable that an alignment film is interposed between the sealing material and the electrode.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a plan view of a liquid crystal display device as a first embodiment of the present invention. In this liquid crystal display device, the common glass substrate 22 is bonded to the segment glass substrate 21 in a planar manner in FIG. A liquid crystal 24 (see FIG. 3) is sealed between the glass substrates 21 and 22. A plurality of segment electrodes and common electrodes, which will be described later, are formed on the inner surfaces of both glass substrates 21 and 22 so as to extend in directions orthogonal to each other, and a plurality of pixels formed by crossing opposing portions of both electrodes are formed in a matrix. It is the composition arranged in. In this case, a rectangular area surrounded by a one-dot chain line inside the sealing material 23 is a display area 25 in which pixels are arranged in a matrix, and the outside thereof is a non-display area 26 where no pixels exist. . In addition, a protruding portion 21 a that protrudes from the common glass substrate 22 is formed on the lower side of the segment glass substrate 21 in FIG. 1. Although not shown, a plurality of connection terminals (segment terminals and common terminals) connected to the segment electrodes and the common electrodes are provided on the upper surface of the protruding portion 21a.
[0010]
Next, FIG. 2 shows an enlarged plan view of a part of the liquid crystal display device shown in FIG. 1, and FIG. 3 shows a sectional view taken along line XX of FIG. On the inner surface of the segment glass substrate 21, a black matrix 31 made of a light-shielding metal such as chrome, red, green and blue color filter elements 32R, 32G and 32B made of colored resin, and a planarizing film made of a resin material such as acrylic resin 33, a segment electrode 34 made of a transparent conductor such as ITO and an alignment film 35 made of a polyimide material are laminated in this order.
[0011]
In this case, the color filter elements 32R, 32G, and 32B are provided only in the display area 25. The black matrix 31 is provided in a lattice shape in the display area 25 so as to correspond to the boundary portions of the color filter elements 32R, 32G, and 32B, and is provided in a rectangular frame shape in the non-display area 26. Further, the peripheral edge portion of the black matrix 31 having a rectangular frame shape is provided up to a position where it enters an appropriate dimension L (for example, about 1/3 or less of the width of the sealing material 23) inside the end surface of the segment glass substrate 21. ing. The peripheral edge portion of the planarizing film 33 is provided to cover the peripheral edge portion of the black matrix 31 and to the vicinity of the end surface of the segment glass substrate 21 on the outer side. The segment electrode 34 is provided in the display region 25 so as to extend in the substrate short direction in FIGS. 1 and 2. Further, for example, the right end portion of FIG. 3 of the segment electrode 34 is extended to the non-display region 26 and provided to the vicinity of the end face of the planarizing film 33 in order to make the gap uniform. The alignment film 35 is provided inside the sealing material 23.
[0012]
Here, the peripheral portion of the black matrix 31 is provided only up to a position that enters the inner side of the outer peripheral surface of the segment glass substrate 21 to some extent, but the peripheral portion of the flattening film 33 covers the peripheral portion of the black matrix 31. Since it is provided to the vicinity of the end face of the segment glass substrate 21 on the outside, the gap can be made uniform as in the conventional case shown in FIG.
[0013]
On the other hand, a common electrode 36 made of a transparent conductor such as ITO and an alignment film 37 made of a polyimide material are laminated on the inner surface of the common glass substrate 22 in this order. In this case, the common electrode 36 is provided in the display region 25 so as to extend in the longitudinal direction of the substrate in FIGS. 1 and 2. Further, the common electrode 36 is also provided in the non-display area 26 on the right side of FIG. 3, for example, in order to make the gap uniform. The alignment film 37 is provided inside the sealing material 23. The sealing material 23 is interposed between the planarizing film 33 having the segment electrode 34 on the surface and the common glass substrate 22 having the common electrode 36 on the surface.
[0014]
As described above, in this liquid crystal display device, the end surface position of the peripheral portion of the black matrix 31 is set to a position where the appropriate length L enters the end surface of the segment glass substrate 21, and the peripheral portion of the planarizing film 33 is the black matrix. 31 is provided so as to cover the periphery of 31 and to the vicinity of the end surface of the segment glass substrate 21 on the outer side thereof. Therefore, the periphery provided on the outer side of the end surface of the black matrix 31 of the planarizing film 33 It is formed by direct contact.
[0015]
In this case, the adhesion between the planarizing film 33 made of a resin material such as an acrylic resin and the segment glass substrate 21 is better than the adhesion between it and the black matrix 31 made of a light-shielding metal such as chromium. Therefore, even if the adhesion strength between the peripheral portion of the black matrix 31 made of chromium and the corresponding portion of the flattening film 33 laminated thereon is slightly weak, the flattening film 33 and the segment glass substrate 21 are strong on the entire outer periphery. , The relatively weak flattening film 33 and the black matrix 31 are prevented from peeling off, and the peeling between the members between the two glass substrates 21 and 22 bonded to each other is effectively prevented. In addition, the bonding strength between the two glass substrates 21 and 22 can be increased.
[0016]
In the above embodiment, the case where the black matrix 31 is formed of a light-shielding metal such as chromium has been described. However, the present invention is not limited to this. For example, as in the second embodiment of the present invention shown in FIG. 4, the black matrix 31 'is formed by laminating red, green and blue color filter elements 32R, 32G and 32B made of colored resin. Also good. Even in this case, even if the adhesion strength between the red, green, and blue color filter elements 32R, 32G, and 32B constituting the rectangular frame-shaped peripheral edge of the black matrix 31 'is slightly weak, Since the planarizing film 33 is directly laminated on the segment glass substrate 21 and is in close contact with the high strength, delamination between the color filter elements 32R, 32G, and 32B is reliably prevented. Therefore, as in the above embodiment, the black matrix 31 ′ composed of the color filter elements 32R, 32G, and 32B stacked at the peripheral edge portions of the two glass substrates 21 and 22, the planarization film 33, the segment electrode 34, and the seal Since the members 23 and the common electrode 36 are in close contact with each other with sufficient strength, separation between the two glass substrates 21 and 22 is effectively prevented.
[0017]
Moreover, although each said embodiment demonstrated the case where the alignment films 35 and 37 were provided inside the sealing material 23, it is not limited to this. For example, as in the third and fourth embodiments of the present invention shown in FIGS. 5 and 6, the alignment films 35 and 37 may be interposed between the sealing material 23 and the electrodes 34 and 36, respectively. . In this case, the material between the glass substrates 21 and 22 is peeled off similarly to the above-described embodiment by using a material having excellent adhesion to the sealing material 23 as the material of the alignment films 35 and 37. It can be surely prevented and the gap can be more evenly secured.
[0018]
Further, for example, in the first embodiment, as shown in FIGS. 2 and 3, the rectangular frame-shaped peripheral edge of the black matrix 31 enters the inside of the end surface of the segment glass substrate 21 by an appropriate length L over the entire periphery. However, the present invention is not limited to this. However, the present invention is not limited to this, although the entire peripheral edge portion of the flattening film 33 is provided to the vicinity of the outer peripheral surface of the segment glass substrate 21 on the outer side.
[0019]
For example, a fifth embodiment of the present invention shown in FIGS. 7 and 8 may be used. In other words, at the four corner portions of the peripheral edge portion forming the rectangular frame shape of the black matrix 31, the corner portions 31b are respectively provided by removing each corner portion into an isosceles right triangle shape. The portion other than the corner portion where the oblique side portion 31 b is formed at the peripheral portion of the black matrix 31 is provided up to the vicinity of the end surface of the segment glass substrate 21. And the planarizing film 33 is provided to the vicinity of the end surface of the segment glass substrate 21 in the whole peripheral part similarly to the said 1st Embodiment etc. Therefore, in this embodiment, the periphery of the planarizing film 33 is directly laminated on the segment glass substrate 21 only at the four corners. By the way, it has been confirmed that peeling between the peripheral portion of the black matrix 31 and the peripheral portion of the planarizing film 33 occurs from four corner portions. Therefore, even with the configuration as in the above-described embodiment, it is possible to effectively prevent peeling between the two glass substrates 21 and 22 bonded together with the sealing material 23, and to increase the bonding strength between the glass substrates 21 and 22. Can be increased.
[0020]
Incidentally, the adhesion strength as a whole of the liquid crystal display device shown in FIGS. 7 and 8, that is, the joint strength between both substrates is 1.3 to 1 of the joint strength between both substrates of the conventional liquid crystal display device shown in FIGS. About 5 times. Even when the black matrix was formed of a resin film such as a laminate of red, green, and blue color filter elements made of colored resin, substantially the same bonding strength was obtained. Further, not only the black matrix but also the planarizing film laminated thereon may be similarly configured such that the corner corners are removed and the sealing material is directly adhered to the glass substrate at the corner corners. In this case, the liquid crystal display The bonding strength between the two substrates of the device is 1.5 to 2.0 times that of the conventional liquid crystal display device shown in FIGS. In this case, the removal end face of the flat film may be set outside the removal end face of the black matrix without aligning the removal end faces of the flattening film and the black matrix, whereby both the flattening film and the sealing material are made of glass. The structure is in direct contact with the substrate. Even if the corner portion of the planarizing film is removed, since the substantially entire periphery excluding the corner portion extends to the vicinity of the substrate end surface, there is no possibility that the gap becomes non-uniform.
In addition, in each of the above embodiments, the electrodes 34 and 36 may be provided only in the display area 25.
[0021]
【The invention's effect】
As described above, according to the present invention, the black matrix and the planarizing film having a film thickness for substantially equalizing the distance between the opposing substrates of the display area and the non-display area are disposed in the sealing material disposition area. The desired gap can be secured uniformly, and at least a part of the peripheral portion of the planarizing film and / or the sealing material provided on the black matrix is directly applied to the inner surface of the glass substrate. Since the adhesion strength between the flattening film and the black matrix is weak because the lamination and fixation are weak, the adhesion strength between the inner surface of the glass substrate, the flattening film and the sealing material is relatively strong. Peeling between the glass substrates can be effectively prevented, and the bonding strength between the two glass substrates can be increased.
[Brief description of the drawings]
FIG. 1 is a plan view of a liquid crystal display device as a first embodiment of the invention.
FIG. 2 is an enlarged plan view of a part of the liquid crystal display device shown in FIG.
3 is a cross-sectional view taken along line XX in FIG.
FIG. 4 is a sectional view similar to FIG. 3 for explaining a second embodiment of the present invention.
FIG. 5 is a cross-sectional view similar to FIG. 3 for explaining a third embodiment of the present invention.
FIG. 6 is a cross-sectional view similar to FIG. 4 shown for explaining a fourth embodiment of the present invention.
FIG. 7 is a plan view similar to FIG. 2 for explaining a fifth embodiment of the present invention.
8 is a cross-sectional view taken along line XX in FIG.
FIG. 9 is a plan view of an example of a conventional liquid crystal display device.
10 is an enlarged plan view of a part of the liquid crystal display device shown in FIG.
11 is a cross-sectional view taken along line YY in FIG.
12 is a cross-sectional view similar to FIG. 11 for explaining another example of a conventional liquid crystal display device.
[Explanation of symbols]
21 segment glass substrate 22 common glass substrate 23 sealing material 24 liquid crystal 25 display area 26 non-display area 31, 31 ′ black matrix 32R, 32G, 32B color filter element 33 flattening film 34 segment electrode 35 alignment film 36 common electrode 37 alignment film

Claims (5)

A black matrix, a planarizing film, and an electrode are stacked in this order on one inner surface of a pair of substrates arranged opposite to each other, and the black matrix, the planarizing film, In the liquid crystal display device in which the pair of substrates are joined by a substantially rectangular frame-shaped sealing material formed so as to surround the region where the electrodes are formed, the black matrix laminated on the one inner surface has a peripheral portion thereof The flattening film is extended to a position where it enters the middle of the width of the sealing material, and the planarizing film has a film thickness for substantially equalizing the distance between the opposing substrates of the display area and the non-display area of the liquid crystal display device. Extending to a position overlapping the entire width of the sealing material, covering the peripheral edge of the black matrix, and extending the electrode until it overlaps the sealing material on the planarizing film. They are respectively formed, a liquid crystal display device, wherein a portion of the periphery of the planarization layer is in close contact in direct contact with said one inner surface in the region overlapping with the sealing material.   2. The liquid crystal display device according to claim 1, wherein a corner portion of a peripheral portion of the planarizing film is in direct contact with and closely contacts the one inner surface.   2. The liquid crystal display device according to claim 1, wherein an edge portion of the flattening film is in direct contact with and closely contacts the inner surface of the flattening film. 4. The liquid crystal display device according to claim 1, wherein the electrode is interposed over the entire width of the sealing material between the sealing material and the planarizing film. .   5. The liquid crystal display device according to claim 4, wherein an alignment film is interposed between the sealing material and the electrode.

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