JP2002131766A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high performance liquid crystal display device wherein no spark is generated between both the counter edges of a pair of transparent electrode parts and an alignment layer is free from turbulence. SOLUTION: In a part of a stage for manufacturing a substrate 19 for a signal used for the liquid crystal display device 17, a signal electrode 21 is divided in the vicinity of a nearly center of a display region 23 on a glass substrate 25 before it is divided to form the pair of transparent electrode parts 26 and 27 arrayed on each line. The end parts on the side opposite to the counter ends of the transparent electrode parts 26 and 27 are respectively connected with a drawer wiring 28 and an electrode terminal 29 and energized and corner parts 32 and 33 of both the counter ends of the transparent electrode parts 26 and 27 are formed in an inclined shape, a curved shape or stepped shape.

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, and more particularly to an improvement in a transparent electrode pattern.

[0002]

2. Description of the Related Art In a liquid crystal display device such as a super twist nematic type, two electrodes each having a transparent electrode formed on a glass substrate and an alignment film formed thereon are prepared. (For example, 5 to 10 μm), a display region is formed, and a seal portion is formed with an organic adhesive along the outer periphery of the display region.

[0005] A part of a process for manufacturing a liquid crystal display device having this structure will be described with reference to FIG. FIG. 2 is a plan view of a glass substrate on which one transparent electrode pattern is formed, and shows a state before the glass substrate is divided at an early stage of a manufacturing process.

[0004] Reference numeral 1 denotes a glass substrate before division. On this glass substrate 1, a transparent electrode pattern 2 in which a plurality of transparent electrodes are arranged in a stripe shape is divided substantially in the vicinity of the center of a display area 3, and each glass substrate is divided. A pair of transparent electrode portions 4 and 5 arranged on a line are formed. Although these transparent electrode portions 4 and 5 face each other,
The ends opposite to the opposite end are connected to the lead wiring 6 and the electrode terminal 7, respectively, and further connected to the connection pattern 9 through the lead transparent electrode pattern 8, and are energized.

In the production of each of these wirings and patterns, a film is formed by vapor deposition or sputtering using ITO or metal, and a photolithography process is performed. Thereafter, an alignment film is formed thereon and then divided. A part of the glass substrate 1 is cut by the line 10 and the connection pattern 9 is removed.

The reason for forming the connection pattern 9 and removing it thereafter is as follows.

After coating an alignment film made of a synthetic resin such as polyimide, the film is rubbed in a certain direction by a roller wrapped with a cloth, so that countless fine scratches are made. A large amount of static electricity is generated due to friction during rubbing. However, as described above, the respective transparent electrode portions 4 and 5 have the same potential due to the connection pattern 9, so that sparks between the transparent electrode portions 4 and 5 due to the static electricity do not occur.

[0008]

On the other hand, in a configuration in which a driving IC is directly mounted on a glass substrate as in a COG type liquid crystal display device, the connection pattern 9 as described above cannot be provided. .

FIG. 6 is a plan view showing a schematic configuration of a glass substrate on which a transparent electrode pattern used for a COG type liquid crystal display device is formed. The same parts as those shown in FIG. 5 are denoted by the same reference numerals.

Reference numeral 11 denotes a glass substrate. On the glass substrate 11, transparent electrode portions 4 and 5 separated from each other near the center of the display area 3 are formed. And the electrode terminal 7.

Reference numeral 12 denotes an area where the driving IC is bonded face-down, and an input terminal 13 is formed along with the bonding area.

In the transparent electrode pattern having the above structure,
Since the transparent electrode portion 4 and the transparent electrode portion 5 are not electrically connected to each other, they are not at the same potential, and therefore, due to static electricity generated in the rubbing step for the alignment film,
Sparks occurred between the transparent electrode portions 4 and 5 in the region 14.

FIGS. 7 to 9 show defect states caused by the spark.
Shown in FIG. 7 shows the transparent electrode portions 4 and 5 in the region 14.
FIG. 4 is an enlarged view of a main part showing the vicinity of FIG. 8 is a cross-sectional view taken along the line aa of FIG. 7, and FIG. 9 is a cross-sectional view taken along the line bb of FIG. Incidentally, reference numeral 15 denotes an alignment film.

As shown in these figures, the spark causes a chip 16 at both ends of the transparent electrode portion 4 and the transparent electrode portion 5, which disturbs the alignment film 15 and affects the alignment of liquid crystal molecules. Had been defective.

Accordingly, the present invention has been devised in view of the above circumstances, and a purpose thereof is to prevent a spark from being generated between both opposing ends of a pair of transparent electrode portions arranged on a line. An object of the present invention is to provide a high-performance liquid crystal display device in which an alignment film is not disturbed.

[0016]

A liquid crystal display device according to the present invention comprises: a substrate on which one transparent electrode pattern in which a plurality of transparent electrodes are arranged in a stripe pattern in one direction and an alignment film are sequentially laminated; The other transparent electrode pattern arranged in a stripe pattern in the other direction and the substrate on which the alignment film is sequentially laminated are arranged to face each other via a liquid crystal layer, and both transparent electrode patterns intersect to form a rectangular display area. A liquid crystal interposed in a display area between the two substrates, wherein one transparent electrode pattern is divided in the other direction near substantially the center of the display area, and a pair of transparent electrodes arranged on each line. It is characterized in that the corners of both opposing ends in the electrode portion are formed in an inclined shape, a curved shape or a stepped shape.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view of a liquid crystal display device 17 of a super twist nematic type such as a COG type, and FIG. 2 is a plan view showing a schematic configuration of a glass substrate on which a transparent electrode pattern is formed. FIGS. 3 and 4 are enlarged views of a main part showing the vicinity of both opposing ends of a pair of transparent electrode portions arranged on each line.

First, the liquid crystal display 17 shown in FIG. 1 will be described. This is a structure in which a glass scanning substrate 18 and a signal substrate 19 are bonded together with a seal portion 20, and a liquid crystal is sealed in a region surrounded by the seal portion 20. The seal portion 20 is made of a thermosetting resin such as an epoxy, acrylic, or silicone resin.

In order to produce such a bonded structure, the scanning side substrate 18 and the signal side substrate 19 are bonded via a sealant, and a space is provided by further positioning.
The sealant is heated and cured to form the seal portion 20. In addition, many non-conductive spacers made of resin spheres are dispersed between the scanning-side substrate 18 and the signal-side substrate 19, so that the distance between the two substrates is kept constant and the liquid crystal is sealed therein. .

On the signal substrate 19, a plurality of signal electrodes 21 as the transparent electrodes are arranged in parallel in a stripe shape, and the arrangement pattern extends to the outside of the seal portion 20. Similarly, a plurality of scanning electrodes 22 are arranged on the scanning substrate 18 in parallel in a stripe pattern, and the arrangement pattern extends to the outside of the seal portion 20. The signal electrode 21 and the scanning electrode 22 are arranged so as to intersect, and the intersecting area becomes a rectangular display area 23. The signal electrode 21 and the scanning electrode 22 are made of indium tin oxide (ITO). Further, an alignment film of a polyimide resin is coated on the signal electrodes 21 and the scanning electrodes 22. Display area 23
A dummy pattern 24 made of ITO or the like is formed between the substrate and the seal portion 20 to keep the thickness between the substrates constant.

FIG. 2 illustrates a part of the process of manufacturing the signal substrate 19 having the above configuration. FIG. 3 is a plan view of the glass substrate on which the one transparent electrode pattern is formed, and shows a state before the glass substrate is divided at an early stage of the manufacturing process.

Reference numeral 25 denotes a glass substrate before division. On the glass substrate 25, the signal electrode 21 is divided in the vicinity of substantially the center of the display area 23, and a pair of transparent electrode portions 26 arranged on each line is formed. , 27. These transparent electrode portions 2
The ends opposite to the opposing ends of 6 and 27 are connected to the lead-out wiring 28 and the electrode terminal 29, respectively, and are energized.

In the production of each of these wirings and patterns, a film is formed by vapor deposition or sputtering using ITO or metal, and a photolithography process is performed. Thereafter, an alignment film is formed thereon and then divided. A part of the glass substrate 25 is cut by the line 30 to form the signal substrate 19.

Further, as described with reference to FIG. 6, the above-mentioned lead wiring 28 and electrode terminal 29 are formed as input terminals in a region where the driving IC is bonded face down. That is, the bonding area,
The input terminal is formed inside the dividing line 30 as shown in FIG. Incidentally, the lead wiring 28 and the electrode terminal 29 correspond to the lead wiring 6 and the electrode terminal 7 shown in FIG. 6, respectively.

FIGS. 3 and 4 show the transparent electrode portions 26 and 27 in a region 31 near the center of the display region 23 shown in FIG.
FIG.

In FIG. 3, the corners 32 of the transparent electrodes 26 and 27 at the opposite ends are inclined.
In FIG. 4, the corners 33 of the transparent electrode portions 26 and 27 at both opposing ends are curved.

Since the accumulated static electricity tends to spark from a pointed portion of the adjacent electrode pattern where a potential difference has occurred, it is difficult to spark by eliminating the pointed shape.
In the liquid crystal display device 17 of the present invention, the signal substrate 19
Since the corners 32, 33 at both opposing ends of the transparent electrode portions 26, 27 are formed in an inclined shape or a curved shape, sharp points at the opposing ends are eliminated. Therefore, even if a large amount of high-potential static electricity is generated by rubbing the alignment film due to the rubbing of the alignment film due to the shape that the static electricity is hard to fly, it is not accumulated locally, and the transparent electrode due to the static electricity Sparks between the parts 26 and 27 do not occur.

FIG. 10 shows an example of the dimensions of the transparent electrode portions 26 and 27 in the case where the corner portions 32 of the opposite ends of the transparent electrode portions 26 and 27 are inclined.

FIG. 10 shows an example of the size of the corner 32 of the inclined shape.
It is preferable that d is 20 μm or more and e is 3 to 10 μm, whereby no spark is generated between the transparent electrode portions 26 and 27, which is the most effective.

Specifically, in the conventional configuration in which d is 20 μm or more and e is 0, sparks occur. However, when e is 1 μm and 2 μm, the sparks slightly increase when the applied voltage increases. Occurred, but there was no practical problem, and e was 3 μm, 4 μm... 9 μm.
In the case of m and 10 μm, no spark was generated. Further, when e was increased to 11 μm or 12 μm, the liquid crystal was not sufficiently driven even if spark did not occur, and a display abnormality occurred.

Further, as shown in FIG.
FIG. 12 shows an example of the dimensions when the corners 33 of the two opposing ends in 27 are curved.

As shown in FIG. 12, f is preferably 20 μm or more, and g of the curved portion is preferably 3 to 10 μm. As a result, no spark is generated between the transparent electrode portions 26 and 27, which is the most effective. is there.

According to an experiment conducted by the present inventor, in the conventional configuration in which f was set to 20 μm or more and g was set to 0, sparks occurred. When the voltage was increased, sparks were slightly generated, but there was no practical problem, and g was 3
In the case of μm, 4 μm... 9 μm, 10 μm, no spark was generated. G is 11 μm,
When it was increased to 12 μm, even if sparks did not occur, the liquid crystal was not sufficiently driven and display abnormalities occurred.

In the present invention, the transparent electrode portion 2
The distance x between the opposite ends 6 and 27 depends on the display accuracy, the number of dots, and the distance between adjacent transparent electrodes, but is preferably set to 7 μm or more. The occurrence of a short circuit between the ends can be most effectively prevented. By increasing the distance x between the two opposing ends of the transparent electrode portions 26 and 27, the degree of occurrence of short-circuit between the opposing ends tends to be small. It was confirmed by experiments that the effects of the invention were exhibited.

Next, another embodiment of the present invention will be described.
In the above-described liquid crystal display device 17, the signal substrate 19
By making the corners 32, 33 of both opposing ends of the transparent electrode portions 26, 27 slanted or curved, the sharp corners of both opposing ends are eliminated, thereby reducing the generation of sparks. Instead, as shown in FIG. 11, the corners 32, 33 of both opposing ends of the transparent electrode portions 26, 27 may be stepped, as shown in FIG. Even if the interval between them is widened, it is possible to prevent both counter electrodes from being short-circuited.

Regarding the step shape, by setting a to 20 μm or more, b to 3 to 10 μm, and c to 1.5 to 2 μm, sparks are not most effectively generated between the transparent electrode portions 26 and 27. .

The present inventor has determined that the distance between the opposing ends x = 7 to 25 μm.
m, a = 20 μm, c = (１ ／) b, and b is 0, 1 μm, 2 μm, 3 μm,.
When it was changed to 11 μm, the following results were obtained.

The occurrence of spark can be determined by short-circuiting the opposing electrode pattern and causing a display defect. Further, the display defect is confirmed by disorder of the orientation of liquid crystal molecules caused by the defect as shown in FIG. You can also.

When b = 0, that is, when there is no step as in the prior art, and also when b = 1 μm, sparks occurred.

In the case of b = 2 μm, the occurrence of spark was confirmed slightly, but there was no practical problem, and b = 3 μm.
m, 4 μm... 7 μm, 8 μm, 9 μm, 10 μm, no spark was generated at all.

Further, when b = 11 μm and b = 12 μm, the liquid crystal was not sufficiently driven, and display abnormalities occurred.

It should be noted that the present invention is not limited to the above embodiment, and various changes and improvements may be made without departing from the scope of the present invention.

For example, in this example, as shown in FIG. 10 to FIG. 12, the inclined shape, the step shape, and the curved shape are respectively used. A configuration combining the shapes, a configuration combining the step shape and the curved shape, or a configuration combining the inclined shape and the curved shape may be adopted.

[0044]

As described above, according to the liquid crystal display device of the present invention, a plurality of transparent electrodes are arranged in a stripe pattern in one direction. The other transparent electrode pattern in which the transparent electrodes are arranged in a stripe pattern in the other direction and a substrate on which an alignment film is sequentially laminated are arranged to face each other via a liquid crystal layer, and both transparent electrode patterns intersect to form a square shape. A liquid crystal is interposed in the display area between the two substrates to form a display area, and one transparent electrode pattern is divided in the other direction near the center of the display area, and a pair of transparent electrodes arranged on each line. By making the corners of the two opposing ends in the electrode portion inclined, curved or stepped, sparks do not occur between the two opposing ends, thereby preventing the alignment film from being disturbed. Fruit, high reliability and high-performance liquid crystal display device could be provided.

Further, according to the present invention, when a quality inspection is performed in the inspection step in the presence of the above-mentioned occurrence of a spark in the production process of the liquid crystal display device of the invention, the quality is improved. As a result, the manufacturing yield was improved, and the manufacturing cost was reduced, whereby a low-cost liquid crystal display device could be provided.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a liquid crystal display device of the present invention.

FIG. 2 is a plan view showing a schematic configuration of a glass substrate on which a transparent electrode pattern is formed in the liquid crystal display device of the present invention.

FIG. 3 is an enlarged view of a main part showing the vicinity of both opposing ends of a pair of transparent electrode portions in the present invention.

FIG. 4 is an enlarged view of a main part showing the vicinity of both opposing ends of a pair of transparent electrode portions in the present invention.

FIG. 5 is a plan view of a glass substrate on which a transparent electrode pattern is formed, which is a part of a process for manufacturing a conventional liquid crystal display device.

FIG. 6 is a plan view illustrating a schematic configuration of a glass substrate on which a transparent electrode pattern is formed, which is a part of a process of manufacturing a conventional liquid crystal display device.

FIG. 7 is an enlarged view of a main part showing the vicinity of a transparent electrode part showing a defect state due to spark.

8 is a cross-sectional view taken along the line aa of FIG. 7;

FIG. 9 is a cross-sectional view taken along line bb of FIG. 7;

FIG. 10 is an enlarged view of a main part of a transparent electrode part having a slanted corner.

FIG. 11 is an enlarged view of a main part of a transparent electrode portion having a stepped corner portion.

FIG. 12 is an enlarged view of a main part of a transparent electrode portion having a curved corner.

[Explanation of symbols]

 Reference Signs List 17 Liquid crystal display device 18 Scanning substrate 19 Signal substrate 21 Signal electrode 22 Scanning electrode 25 Glass substrate before division 26, 27 Transparent electrode Part 28: Lead-out wiring 29: Electrode terminal 30: Dividing line 31: Area near the center of the display area 32, 33: Corner

Claims (1)

[Claims] 1. A substrate in which one transparent electrode pattern in which a plurality of transparent electrodes are arranged in a stripe pattern in one direction and an alignment film are sequentially laminated, and the other in which a plurality of transparent electrodes are arranged in a stripe pattern in another direction. A substrate on which a transparent electrode pattern and an alignment film are sequentially laminated is disposed to face each other via a liquid crystal layer, and both transparent electrode patterns intersect to form a rectangular display area. An interposed liquid crystal display device, wherein one transparent electrode pattern is divided along the other direction near the center of the display area, and corners of both opposing ends in a pair of transparent electrode portions arranged on each line. A liquid crystal display device characterized in that the portion has an inclined shape, a curved shape or a stepped shape.