JP4712954B2 - Liquid crystal display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly to improvement of a transparent electrode pattern.
[0002]
[Prior art]
For a liquid crystal display device such as a super twist nematic type, two transparent electrodes are formed on a glass substrate and an alignment film is formed on the glass substrate, and both are provided at a predetermined interval (for example, 5 to 10 μm) via a liquid crystal layer. In this structure, a display region is formed opposite to each other, and a seal portion is formed with an organic adhesive along the outer periphery of the display region.
[0003]
Part of a process for manufacturing the liquid crystal display device having this structure will be described with reference to FIGS.
This figure 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 the initial stage of the manufacturing process.
[0004]
Reference numeral 1 denotes a glass substrate before dividing. 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 in the vicinity of the center of the display region 3, and on each line. A pair of transparent electrode portions 4 and 5 are arranged. These transparent electrode portions 4 and 5 are opposed to each other, but their opposite ends are connected to the lead wiring 6 and the electrode terminal 7, respectively, and are further connected to the connection pattern 9 through the lead transparent electrode pattern 8. Energized.
[0005]
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. After that, an alignment film is formed on these, and then a dividing line 10 is formed. Accordingly, a part of the glass substrate 1 is cut and the connection pattern 9 is removed.
[0006]
The reason why the connection pattern 9 is formed in this way and then removed is as follows.
[0007]
After applying an alignment film made of a synthetic resin such as polyimide, the film is rubbed in a fixed direction with a cloth-rolled roller to give countless fine scratches. A large amount of static electricity is generated due to friction. However, as described above, the transparent electrode portions 4 and 5 have the same potential due to the connection pattern 9, and as a result, no spark occurs between the transparent electrode portions 4 and 5 due to the static electricity.
[0008]
[Problems to be solved by the invention]
On the other hand, in the configuration in which the driving IC is directly mounted on the glass substrate as in the COG type liquid crystal display device, the connection pattern 9 as described above cannot be provided.
[0009]
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.
[0010]
Reference numeral 11 denotes a glass substrate. On the glass substrate 11, transparent electrode portions 4 and 5 are formed which are divided in the vicinity of the center of the display region 3, and these end portions are respectively drawn wiring 6 and electrode terminals. 7 is connected.
[0011]
Reference numeral 12 denotes a region where the driving IC is bonded face down, and the input terminal 13 is formed accordingly.
[0012]
In the transparent electrode pattern having the above configuration, the transparent electrode portion 4 and the transparent electrode portion 5 are not electrically connected, and thus are not at the same potential. For this reason, due to static electricity generated in the rubbing process for the alignment film, A spark occurred between the transparent electrode portions 4 and 5 in the region 14.
[0013]
The defect state by this spark is shown in FIGS.
FIG. 7 is an essential part enlarged view showing the vicinity of the transparent electrode portion 4 and the transparent electrode portion 5 in the region 14. 8 is a cross-sectional view taken along section line aa in FIG. 7, and FIG. 9 is a cross-sectional view taken along section line bb in FIG. Reference numeral 15 denotes an alignment film.
[0014]
As shown in these figures, the chip 16 is generated at the tip of both the transparent electrode portion 4 and the transparent electrode portion 5 due to the spark, thereby disturbing the alignment film 15 and affecting the alignment of the liquid crystal molecules, resulting in a display defect. It was.
[0015]
Therefore, the present invention has been devised in view of the above circumstances, and the purpose thereof is to prevent the occurrence of sparks between the opposing ends of the pair of transparent electrode portions arranged on the line, and to the alignment film. An object is to provide a high-performance liquid crystal display device free from disturbance.
[0016]
[Means for Solving the Problems]
The liquid crystal display device of the present invention includes a transparent substrate having one transparent electrode pattern in which a plurality of transparent electrodes are arranged in a stripe shape in one direction , and a first substrate provided with an alignment film , and a plurality of transparent electrodes in a stripe shape in the other direction. A second substrate provided with an alignment film and the other transparent electrode pattern that is arranged and intersected with the one transparent electrode pattern in plan view , and a liquid crystal interposed between the first substrate and the second substrate And the one transparent electrode pattern is divided along the other direction, and the corners at the opposite ends of the divided one transparent electrode pattern are inclined or curved, and the one direction and length Saga 3 to 10 mu m of the corner portion in the other direction, the length of the transparent electrode Saga 20 [mu] m or more between the corners in the other direction, and in a distance between the opposite ends of each other 7μm or more is there.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The liquid crystal display device of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic plan view of a super twist nematic type liquid crystal display device 17 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. FIG. 3 and FIG. 4 are enlarged views of the main part showing the vicinity of both opposing ends in a pair of transparent electrode portions arranged on each line.
[0018]
First, the liquid crystal display device 17 shown in FIG. 1 will be described.
The glass scanning substrate 18 and the signal substrate 19 are bonded together with a seal portion 20, and liquid crystal is sealed in a region surrounded by the seal portion 20. The seal part 20 is made of a thermosetting resin such as epoxy, acrylic or silicone.
[0019]
In order to fabricate 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, and the sealant is heated. The seal portion 20 is formed by curing. In addition, a large amount of non-conductive spacers made of resin spheres are dispersed between the scanning side substrate 18 and the signal side substrate 19, thereby keeping the distance between the substrates constant and enclosing the liquid crystal therein. .
[0020]
On the signal substrate 19, a plurality of signal electrodes 21 that are 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 in parallel on the scanning substrate 18 in a stripe shape, 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 with each other, and the intersecting region becomes a rectangular display region 23. The signal electrode 21 and the scanning electrode 22 are made of indium tin oxide (ITO) or the like. Further, an alignment film of polyimide resin is coated on the signal electrode 21 and the scanning electrode 22. A dummy pattern 24 made of ITO or the like is formed between the display area 23 and the seal portion 20 so that the thickness between the substrates is constant.
[0021]
FIG. 2 illustrates a part of the process of manufacturing the signal substrate 19 having the above-described configuration.
This figure 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 the initial stage of the manufacturing process.
[0022]
Reference numeral 25 denotes a glass substrate before being divided. On this glass substrate 25, the signal electrode 21 is divided in the vicinity of the center of the display area 23, and a pair of transparent electrode portions 26 and 27 arranged on each line are arranged. Eggplant. The ends of the transparent electrode portions 26 and 27 opposite to the opposite end portions are connected to the lead wiring 28 and the electrode terminal 29, respectively, and are energized.
[0023]
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 a dividing line 30 is formed. Accordingly, a part of the glass substrate 25 is cut to form the signal substrate 19.
[0024]
Further, as described with reference to FIG. 6, the lead wiring 28 and the electrode terminal 29 are formed as input terminals in the region where the driving IC is bonded face down. That is, the bonding region and the input terminal are formed inside the dividing line 30 as shown in FIG. Incidentally, the lead wire 28 and the electrode terminal 29 correspond to the lead wire 6 and the electrode terminal 7 shown in FIG. 6, respectively.
[0025]
3 and 4 are enlarged views of the main part of the transparent electrode portions 26 and 27 in the region 31 near the center of the display region 23 shown in FIG.
[0026]
In FIG. 3, the corner portions 32 at both opposing ends of the transparent electrode portions 26 and 27 are inclined. Moreover, in FIG. 4, the corner | angular part 33 of both the opposing ends in the transparent electrode parts 26 and 27 is made into the curve shape.
[0027]
The accumulated static electricity is likely to spark from the pointed portion of the adjacent electrode pattern that caused the potential difference. Therefore, it becomes difficult to spark by eliminating the pointed shape, but in the liquid crystal display device 17 of the present invention, the signal substrate 19 In the transparent electrode portions 26 and 27, the corner portions 32 and 33 at both opposing ends are inclined or curved so that the corner portions at both opposing ends are not sharp. Therefore, by forming a shape that prevents static electricity from flying, the alignment film is rubbed, and even if a large amount of high-potential static electricity generated by friction is generated, it will not accumulate locally, and the transparent electrode due to the static electricity The spark between the parts 26 and 27 does not occur.
[0028]
FIG. 10 shows an example of the dimensions in the case where the corner portions 32 at both opposing ends of the transparent electrode portions 26 and 27 are inclined as shown in FIG.
[0029]
FIG. 10 shows an example of the dimensions of the inclined corner portion 32. According to experiments repeatedly conducted by the present inventor, d is preferably 20 μm or more, and e is 3 to 10 μm. No sparks occur between 27 and is the most effective.
[0030]
Specifically, in the conventional configuration in which d is set to 20 μm or more and e is set to 0, a spark is generated, but when e is 1 μm and 2 μm, a slight spark is generated when the applied voltage is increased. However, there was no problem in practical use, and when e was 3 μm, 4 μm... 9 μm, 10 μm, no spark was generated. Further, when e is increased to 11 μm and 12 μm, even if no spark is generated, the liquid crystal is not sufficiently driven and a display abnormality occurs.
[0031]
FIG. 12 shows an example of the dimensions when the corners 33 at both opposing ends of the transparent electrode portions 26 and 27 are curved as shown in FIG.
[0032]
As shown in FIG. 12, it is preferable that f is 20 μm or more, and g of the curved portion is 3 to 10 μm, so that no spark is generated between the transparent electrode portions 26 and 27, which is most effective.
[0033]
According to an experiment conducted by the present inventor, spark was generated in the conventional configuration in which f was set to 20 μm or more and g was set to 0. However, when g was 1 μm and 2 μm, the applied voltage was large. In this case, a slight spark was generated, but there was no practical problem. Further, when g was 3 μm, 4 μm... 9 μm, 10 μm, no spark was generated. Further, when g was increased to 11 μm and 12 μm, the liquid crystal was not sufficiently driven even if no spark was generated, and display abnormality occurred.
[0034]
In the present invention, the distance x between the opposing ends of the transparent electrode portions 26 and 27 is preferably set to 7 μm or more, although it depends on the display accuracy, the number of dots, and the distance between adjacent transparent electrodes. Therefore, the occurrence of a short circuit between the opposing ends of the transparent electrode portions 26 and 27 can be most effectively prevented. Then, by increasing the distance x between the opposing ends of the transparent electrode portions 26 and 27, the degree of occurrence of a short circuit between the opposing ends tends to decrease, but even if the distance x is increased to 25 μm, It was confirmed by experiments that the effects of the invention were achieved.
[0035]
Next, another embodiment of the present invention will be described.
In the liquid crystal display device 17 described above, the corner portions 32 and 33 at both opposing ends of the transparent electrode portions 26 and 27 in the signal substrate 19 are inclined or curved so that the corner portions at both opposing ends are formed. This prevents the occurrence of sparks, thereby preventing the occurrence of sparks. Instead, as shown in FIG. 11, the corners 32 and 33 at the opposite ends of the transparent electrode portions 26 and 27 are stepped. It is also possible to prevent the opposing electrodes from being short-circuited by increasing the distance between the corners of the opposing ends.
[0036]
With respect to the stepped shape, a is set to 20 μm or more, b is set to 3 to 10 μm, and c is set to 1.5 to 2 μm, so that sparks are not generated most effectively between the transparent electrode portions 26 and 27.
[0037]
The present inventor defined the gaps x = 7 to 25 μm, a = 20 μm, c = (1/2) b, and b was changed to 0, 1 μm, 2 μm, 3 μm... 10 μm, 11 μm. However, the following results were obtained.
[0038]
The occurrence of a spark can be determined by shorting the opposing electrode pattern to cause a display defect. Furthermore, the display defect can be confirmed by the disorder of the orientation of liquid crystal molecules caused by the defect as shown in FIG. it can.
[0039]
When b = 0, that is, when there is no step as in the prior art, and when b = 1 μm, sparking occurred.
[0040]
In the case of b = 2 μm, the occurrence of a slight spark was confirmed, but there was no practical problem, and in the case of b = 3 μm, 4 μm... 7 μm, 8 μm, 9 μm, 10 μm, a spark was generated at all. There wasn't.
[0041]
Further, when b = 11 μm and 12 μm, the liquid crystal was not sufficiently driven and display abnormality occurred.
[0042]
In addition, this invention is not limited to the said embodiment, A various change, improvement, etc. do not interfere in the range which does not deviate from the summary of this invention.
[0043]
For example, in this example, as shown in FIGS. 10 to 12, each has an inclined shape, a step shape, or a curved shape, but instead of this, a shape that combines these shapes, that is, an inclined shape and a step shape. A combined configuration, a configuration combining a step shape and a curved shape, or a configuration combining an inclined shape and a curved shape may be used.
[0044]
【The invention's effect】
As described above, according to the liquid crystal display device of the present invention, one transparent electrode pattern in which a plurality of transparent electrodes are arranged in stripes in one direction, a first substrate provided with an alignment film , and a plurality of transparent electrodes Between the first substrate and the second substrate, the second transparent electrode pattern arranged in stripes in the other direction and crossing the one transparent electrode pattern in plan view , and the second substrate provided with the alignment film An intervening liquid crystal layer, and one transparent electrode pattern is divided along the other direction, and the corners at the opposite ends of the divided one transparent electrode pattern are inclined or curved, and unidirectional and length Saga 3 to 10 mu m of the corners of the other direction, over a length Saga 20 [mu] m of the transparent electrode between the corners of the other direction, and since the distance between the mutual facing end is 7μm or more, Between the opposite ends of both Park is not generated, thereby, disturbance in the alignment film is no longer occurring, as a result, could be provided reliable and high-performance liquid crystal display device.
[0045]
In addition, according to the present invention, when manufacturing the liquid crystal display device of the present invention, in the inspection process, when quality inspection is performed with or without the occurrence of sparks as described above, the quality is improved. The yield was improved and the manufacturing cost was reduced, thereby providing a low-cost liquid crystal display device.
[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 showing a schematic configuration 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. 7 is an enlarged view of a main part showing the vicinity of a transparent electrode part showing a defect state due to a spark.
8 is a cross-sectional view taken along a cutting plane line aa in FIG. 7;
9 is a cross-sectional view taken along section line bb in FIG.
FIG. 10 is an enlarged view of a main part of a transparent electrode part having corners inclined.
FIG. 11 is an enlarged view of a main part of a transparent electrode part with corners having a stepped shape.
FIG. 12 is an enlarged view of a main part of a transparent electrode portion having a corner portion curved.
[Explanation of symbols]
17 ... Liquid crystal display device 18 ... Scanning substrate 19 ... Signal substrate 21 ... Signal electrode 22 ... Scanning electrode 25 ... Glass substrate 26, 27 before separation: Transparent electrode Section 28 ... Lead-out wiring 29 ... Electrode terminal 30 ... Dividing line 31 ... Areas 32, 33 ... near the center of the display area

Claims (1)

One transparent electrode pattern in which a plurality of transparent electrodes are arranged in a stripe in one direction , and a first substrate provided with an alignment film ;
A second substrate in which a plurality of transparent electrodes are arranged in stripes in the other direction and the other transparent electrode pattern intersects with the one transparent electrode pattern in plan view , and a second substrate provided with an alignment film ;
A liquid crystal layer interposed between the first substrate and the second substrate,
The one transparent electrode pattern is divided along the other direction, and the corners of the one transparent electrode pattern that are divided are opposed to each other at an inclined shape or a curved shape,
Length Saga 3 to 10 mu m of the angle portion in one direction and the other direction, the transparent head of the electrode Saga 20 [mu] m or more between the corners in the other direction, and the distance between the opposite ends of each other A liquid crystal display device having a thickness of 7 μm or more.

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