JPH11295718A - Panel for liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent misalignment from occurring in a part corresponding to pixel electrode in an active matrix panel of a liquid crystal display device. SOLUTION: A black mask 8 is arranged on a thin film transistor 4. And, a drain line 3 containing the thin film transistor 4 and the black mask 8 is arranged in parallel with the rubbing direction of an alignment layer 9 shown by the arrow. Therefore, even if the thin film transistor 4 and the black mask cause alignment defect as obstacles at the time of rubbing process, the region where the alignment defect is caused, namely, the region enclosed by the two-dot chain line is located on the drain line 3, so it is possible to prevent the alignment defect from being caused in a part corresponding to a pixel electrode 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display panel.

[0002]

2. Description of the Related Art For example, an active matrix type liquid crystal display device has an active matrix panel (liquid crystal) having a gate line (scanning line), a drain line (signal line), a thin film transistor as a switching element, and a pixel electrode on one surface. Liquid crystal is sealed between a display panel) and a common electrode panel (liquid crystal display panel) having a common electrode on one surface.

FIG. 7 is a plan view of a part of an example of an active matrix panel in such a conventional liquid crystal display device, and FIG. 8 is a sectional view taken along line XX. This active matrix panel has a glass substrate 1. A gate line 2 and a drain line 3 are provided on the upper surface side of the glass substrate 1 in a direction orthogonal to each other, and a thin film transistor 4 and a pixel electrode 5 are provided near each intersection.

That is, the thin film transistor 4 and the gate insulating film 6 are provided on the upper surface of the glass substrate 1. In this case, although not shown in FIG. 8, a gate line 2 is provided at a predetermined position between the glass substrate 1 and the gate insulating film 6 so as to be connected to the thin film transistor 4. A pixel electrode 5 is provided at a predetermined location on the upper surface of the gate insulating film 6 so as to be connected to the thin film transistor 4, and a drain line 3 is provided at another predetermined location connected to the thin film transistor 4. An overcoat film 7 is provided on the periphery of the pixel electrode 5, the thin film transistor 4, the drain line 3, and the upper surface of the gate insulating film 6. On the upper surface of the overcoat film 7 corresponding to the thin film transistor 4, a black mask 8 made of resin black is provided. An alignment film 9 is provided on the upper surface of the overcoat film 7 including the black mask 8 and the upper surface of the pixel electrode 5. When the liquid crystal display device is of a twisted nematic type, the upper surface of the alignment film 9 is made of a rubbing cloth made of a woven cloth or felt or the like to form the gate line 2 or the drain line 3.
The rubbing process is performed by rubbing in the direction of 45 °, that is, in the direction of the arrow in FIG.

[0005]

However, in such a conventional active matrix panel, the portion of the thin film transistor 4 and the black mask 8 is significantly protruded as compared with the other portions, so that during the rubbing process,
The portion of the thin film transistor 4 and the black mask 8 may be an obstacle, and an alignment defect may occur from the portion of the thin film transistor 4 and the black mask 8 to a region surrounded by a two-dot chain line in the direction of the arrow in FIG. Since it is located on the electrode 5, there is a problem that the display quality may be deteriorated. An object of the present invention is to prevent alignment failure from occurring at a portion corresponding to a pixel electrode.

[0006]

According to the first aspect of the present invention,
A scanning line and a signal line are provided on one surface in a direction orthogonal to each other, a switching element and a pixel electrode are provided near each intersection thereof, an alignment film is provided thereon, and a formation region of the switching element is provided. In the liquid crystal display panel having a protruding portion, the protruding portions are spaced apart in a direction parallel and orthogonal to a rubbing direction of the alignment film, and are arranged in a region between the protruding portions in a direction parallel to the rubbing direction of the alignment film. The pixel electrodes adjacent to each other are separated. According to the first aspect of the present invention, the protrusions are spaced apart in a direction parallel and orthogonal to the rubbing direction of the alignment film, and pixels adjacent to each other in a region between the protrusions in a direction parallel to the rubbing direction of the alignment film. Since the electrodes are separated, during the rubbing process, even if the protrusions become obstacles and poor alignment occurs, the region where the poor alignment occurs will be located between adjacent pixel electrodes, Therefore, it is possible to prevent poor alignment from occurring at a portion corresponding to the pixel electrode. According to a fifth aspect of the present invention, a black mask and a plurality of color filter elements are provided on one surface, and a plurality of columnar spacers are formed by a portion where the plurality of color filter elements are overlapped. In a liquid crystal display panel having an alignment film provided thereon, the spacers are spaced apart in a direction parallel and orthogonal to a rubbing direction of the alignment film, and a part of the black mask is parallel to a rubbing direction of the alignment film. In a region between the spacers in different directions. According to the fifth aspect of the present invention, the spacers are spaced apart in a direction parallel and perpendicular to the rubbing direction of the alignment film, and a part of the black mask is formed between the spacers in a direction parallel to the rubbing direction of the alignment film. Polymerized to
During the rubbing process, even if the spacer becomes an obstacle and an alignment defect occurs, the region where the alignment defect has occurred will be located on the black mask, and therefore an alignment defect will occur at the portion corresponding to the pixel electrode. Can not be.

[0007]

(First Embodiment) FIG. 1 is a plan view of a main part of an active matrix panel to which a first embodiment of the present invention is applied, and FIG. 2 is a cross-sectional view taken along the line XX. It is shown. In these figures, the same reference numerals are given to the same parts as those in FIGS. 7 and 8, and the description thereof will be omitted as appropriate. In this active matrix panel,
As shown by the arrow in FIG. 1, the rubbing direction of the alignment film 9 is substantially four times the vertical direction or the horizontal direction of the glass substrate 1.
It is inclined by 5 °. The gate line 2 is provided orthogonal to the rubbing direction of the alignment film 9 shown by the arrow in FIG. 1, that is, provided at an angle of approximately 45 ° with respect to the vertical direction or the horizontal direction of the glass substrate 1. The drain line 3 is provided in parallel with the rubbing direction of the alignment film 9 indicated by the arrow in FIG. 1, that is, at an angle of approximately 45 ° with respect to the vertical direction or the horizontal direction of the glass substrate 1. Therefore, the gate line 2 and the drain line 3 are provided in directions orthogonal to each other. A thin film transistor 4 and a black mask 8 are provided near each intersection of the gate line 2 and the drain line 3. That is, the thin film transistors 4 and the black masks 8 are spaced apart from each other in a direction parallel and orthogonal to the rubbing direction of the alignment film 9 shown by the arrow in FIG. In this case, the drain line 3 is bent in a U-shape at the thin film transistor 4 and the black mask 8. Also,
The region where the thin film transistor 4 and the black mask 8 are formed is a projection. A pixel electrode 5 is provided near each intersection of the gate line 2 and the drain line 3. Each side of the pixel electrode 5 is provided to be inclined at approximately 45 ° with respect to the vertical direction or the horizontal direction of the glass substrate 1. A region between the adjacent thin film transistors 4 and the black mask 8 in a direction parallel to the rubbing direction of the alignment film 9 indicated by an arrow in FIG. It is located in. That is, adjacent pixel electrodes 5 are separated in a region between the thin film transistor 4 and the black mask 8 in a direction parallel to the rubbing direction of the alignment film 9 indicated by the arrow in FIG.

As described above, in this active matrix panel, the thin film transistors 4 and the black masks 8 are arranged in a direction parallel and perpendicular to the rubbing direction of the alignment film 9 shown by the arrow in FIG. Since the pixel electrodes 5 adjacent to each other are separated in a region between the thin film transistor 4 and the black mask 8 in a direction parallel to the rubbing direction of the film 9, the thin film transistor 4 and the black mask 8 become obstacles during the rubbing process. Even if the alignment failure occurs, the region where the alignment failure has occurred, that is, the region surrounded by the two-dot chain line in FIG. 1 is located on the drain line 3 between the pixel electrodes 5 adjacent to each other. 5 can be prevented from causing poor alignment. Further, even when the black mask 8 is not provided on the thin film transistor 4, the thin film transistor 4 becomes an obstacle during the rubbing treatment because the portion of the thin film transistor 4 is protruded as compared with the other portions, resulting in poor alignment. Even in such a case, similarly to the above, it is possible to prevent the occurrence of poor alignment at the portion corresponding to the pixel electrode 5.

(Second Embodiment) FIG. 3 is a sectional view showing a main part of an active matrix panel to which a second embodiment of the present invention is applied. In this figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. In this active matrix panel, color filter elements R, G, and B of three colors of red, green, and blue are provided on the upper surface of the pixel electrode 5 and the overcoat film 7, and a black mask is provided on a portion corresponding to the thin film transistor 4 on the upper surface. 8 is provided, and an alignment film 9 is provided on the upper surfaces of the color filter elements R, G, and B including the black mask 8. In this case, a portion (projection) where the thin film transistor 4, the color filter elements R, G, B, and the black mask 8 are superposed greatly protrudes as compared with other portions. Even in the case where the defective portion becomes an obstacle and poor alignment may occur, the poor alignment can be prevented from occurring in the portion corresponding to the pixel electrode 5 as in the first embodiment.

(Third Embodiment) FIG. 4 is a sectional view showing a main part of an active matrix panel to which a third embodiment of the present invention is applied. In this figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. In this active matrix panel, three color filter elements R, G, and B of red, green, and blue are provided on the upper surfaces of the pixel electrodes 5 and the overcoat film 7. In this case, the color filter elements R, G, and B have three layers in a portion corresponding to the thin film transistor 4. The columnar spacer 11 is constituted by the three layers of the color filter elements R, G, and B. An alignment film 9 is provided on the upper surfaces of the color filter elements R, G, B. As described above, since the portion (projection) where the thin film transistor 4 and the columnar spacer 11 are superposed greatly protrudes as compared with the other portions, the superposed portion becomes an obstacle during the rubbing process. Even in the case where misalignment may occur, the misalignment can be prevented from occurring in a portion corresponding to the pixel electrode 5 as in the case of the first embodiment. In addition, since the color filter elements R, G, and B, which are three layers, are black as a whole, they also serve as a black mask in addition to the role of the spacer. However, the color filter element R having three layers,
A black mask may be further provided on G and B.

(Fourth Embodiment) FIG. 5 is a bottom view of a main part of a common electrode panel to which a fourth embodiment of the present invention is applied, and FIG. 6 is a cross-sectional view taken along the line XX. It is. This common electrode panel has a glass substrate 21. On the lower surface of the glass substrate 21, a black mask 22 made of chromium or the like is provided in a lattice shape. In this case, a part of the black mask 22, that is, a predetermined part is provided in parallel with the direction shown by the arrow in FIG. 5, and the remaining part is provided orthogonal to the direction shown by the arrow in FIG. That is, a part of the black mask 22 is inclined at approximately 45 ° with respect to the vertical direction or the horizontal direction of the glass substrate 21, and the remaining portion is inclined at approximately 45 ° with respect to the vertical direction or the horizontal direction of the glass substrate 21 . On the lower surface of the glass substrate 21 including the black mask 22, three color filter elements R, G, and B of red, green, and blue are provided. In this case, the color filter elements R, G, and B have three layers below the black mask 22 and at, for example, a portion corresponding to the thin film transistor 4 of the active matrix panel shown in FIG. The columnar spacer 25 is constituted by the three layers of the color filter elements R, G, and B. In this case, the spacers 25 are spaced apart in a direction parallel and perpendicular to the direction indicated by the arrow in FIG. 5, and are located below the black mask 22. Further, a region between the spacers 25 in a direction parallel to the direction indicated by the arrow in FIG. 5 is located below a part of the black mask 22. That is, a part of the black mask 22 is superimposed on a region between the spacers 25 in a direction parallel to the direction indicated by the arrow in FIG. A common electrode 23 is provided on the lower surface of the color filter elements R, G, and B, and an alignment film 24 is provided on the lower surface. Then, the lower surface of the alignment film 24 is rubbed with a rubbing cloth made of woven cloth, felt, or the like in the direction of the arrow in FIG.

As described above, in this common electrode panel, the spacers 25 are spaced apart in the direction parallel and perpendicular to the rubbing direction of the alignment film 24 shown by the arrow in FIG. Are overlapped in the region between the spacers 25 in the direction parallel to the rubbing direction, and even if the spacer 25 becomes an obstacle during the rubbing process and a poor alignment occurs, the region where the poor alignment occurs, that is, FIG. The region surrounded by the two-dot chain line 5 is located below the black mask 22, so that it is possible to prevent the occurrence of poor alignment at the portion corresponding to the pixel electrode. In addition, by combining with the active matrix panel to which the first embodiment is applied, it is possible to form a liquid crystal display device in which alignment failure does not occur in a portion corresponding to a pixel electrode.

[0013]

As described above, according to the first aspect of the present invention, the protruding portions are spaced apart in a direction parallel and perpendicular to the rubbing direction of the alignment film, and are arranged in a direction parallel to the rubbing direction of the alignment film. Since the pixel electrodes adjacent to each other are separated in the region between the protrusions, even if the protrusions become obstacles during the rubbing process and poor alignment occurs, the regions where the poor alignment occurs are adjacent to each other. It is located between the pixel electrodes, and therefore, it is possible to prevent the occurrence of poor alignment at a portion corresponding to the pixel electrodes. According to the fifth aspect of the present invention, the spacers are spaced apart in a direction parallel and perpendicular to the rubbing direction of the alignment film, and a part of the black mask is provided in a region between the spacers in a direction parallel to the rubbing direction of the alignment film. Due to the polymerization, even if the spacer becomes an obstacle during the rubbing treatment and an alignment failure occurs, the region where the alignment failure has occurred is located on the black mask, and thus corresponds to the pixel electrode. It is possible to prevent the occurrence of poor orientation in the portion.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of an active matrix panel to which a first embodiment of the present invention has been applied.

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

FIG. 3 is a sectional view of a main part of an active matrix panel to which a second embodiment of the present invention has been applied.

FIG. 4 is a sectional view of a main part of an active matrix panel to which a third embodiment of the invention is applied.

FIG. 5 is a bottom view of a main part of a common electrode panel to which a fourth embodiment of the present invention is applied.

FIG. 6 is a sectional view taken along the line XX of FIG. 5;

FIG. 7 is a plan view of a part of an example of a conventional active matrix panel.

FIG. 8 is a sectional view taken along line XX of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Gate line 3 Drain line 4 Thin film transistor 5 Pixel electrode 8 Black mask 9 Alignment film 11 Spacer 21 Glass substrate 22 Black mask 24 Alignment film 25 Spacer R, G, B Color filter element

Claims (5)

[Claims] 1. A scanning line and a signal line are provided on one surface in a direction orthogonal to each other, a switching element and a pixel electrode are provided near each intersection thereof, and an alignment film is provided thereon. In a liquid crystal display panel in which an element formation region is a projection, the projections are arranged in a direction parallel and orthogonal to a rubbing direction of the alignment film, and the projections in a direction parallel to a rubbing direction of the alignment film are provided. A liquid crystal display panel, wherein adjacent pixel electrodes are separated in a region between the sections. 2. The liquid crystal display panel according to claim 1, wherein the protruding portion has a black mask made of resin black formed on the switching element. 3. The liquid crystal display panel according to claim 1, wherein the protrusion has a color filter element formed on the switching element and a black mask made of resin black. 4. The liquid crystal display panel according to claim 1, wherein the projecting portion is formed in a column shape in which color filter elements of a plurality of colors are overlapped on the switching element, and also serves as a spacer. 5. A black mask and color filter elements of a plurality of colors are provided on one surface, and a plurality of columnar spacers are formed by a portion where the color filter elements of the plurality of colors are overlapped with each other. In a liquid crystal display panel provided with a film, the spacers are arranged separately in a direction parallel and orthogonal to the rubbing direction of the alignment film, and a part of the black mask is aligned in a direction parallel to the rubbing direction of the alignment film. A panel for liquid crystal display, wherein the panel is superposed in a region between the spacers.