JP2875645B2 - Liquid crystal display device - Google Patents

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 device, and more particularly, to a shape and an arrangement of dummy electrodes formed in a non-display area.

[0002]

2. Description of the Related Art As shown in FIG. 5, a liquid crystal display element comprises an upper electrode substrate 2 having an upper transparent electrode 1 formed on one surface and a lower electrode substrate 4 having a lower transparent electrode 3 formed on one surface.
The transparent electrodes 1 and 3 are placed inside, and the transparent electrode forming surfaces of the electrode substrates 2 and 4 are bonded together via a predetermined cell gap G, and a liquid crystal (not shown) is sealed in the cell gap G. In addition, an upper polarizer 5 and a lower polarizer 6 are provided on the outer surfaces of the electrode substrates 2 and 4. In general, a liquid crystal display element is required to have high cell gap accuracy.
TN (Super Twisted Nematic) type and full color TFT
(Thin Film Tran-sistor) type liquid crystal display elements require extremely high cell gap accuracy of ± 0.1 μm or less, and multi-tone black and white type liquid crystal display elements require ± 0.05 μm or less.

As shown in FIG. 6, an upper transparent electrode 1 and a lower transparent electrode 3 are arranged at right angles, and the upper transparent electrode 1 and the lower transparent electrode 3 are divided into a plurality of groups, which are different from each other. Flexible substrates 7a, 7
, 7c,... mounted on the driver ICs 8a, 8
In the dot matrix type liquid crystal display element connected to the output terminals b, 8c,.
In order to facilitate the mounting of a, 7b, 7c,..., the ends of the transparent electrode groups are generally gathered and pulled out to the ends of the upper electrode substrate 2 or the lower electrode substrate 4,
Connected to electrode terminal 9. Therefore, the first driver I
Between the first transparent electrode group 1a connected to the first driver IC 8a and the second transparent electrode group 1b connected to the second driver IC 8b disposed adjacent to the first driver IC 8a; A non-display area 10 having no transparent electrode is formed in the outermost part of the non-display area. Note that reference numeral 11 in FIG.
Denotes a lead pattern formed on the flexible substrates 7a, 7b, 7c,..., And 12 denotes a printed wiring board on which a circuit pattern 13 for driving a liquid crystal display element is formed. The electrode terminal 9 and the lead pattern 11, and the lead pattern 11 and the circuit pattern 13 are connected via an anisotropic conductive sheet (not shown).

As described above, in a liquid crystal display element in which the non-display area 10 having no transparent electrodes 1 and 3 is dispersedly arranged in the display area constituted by the transparent electrodes 1 and 3, The transparent electrodes 1 and 3 are
The cell gap G is different by the thickness of the display region, and there is a problem that color unevenness portions are likely to be dotted around the display area. In order to improve such inconvenience, as shown in FIG. 7, conventionally, the non-display area 10 has a thickness equivalent to that of the transparent electrodes 1 and 3 and is electrically independent of the transparent electrodes 1 and 3 for information. An electrode which is not involved in display, that is, a dummy electrode 14 is provided to make the cell gap G uniform.

[0005]

However, in the prior art, since the dummy electrode 14 is formed in such a shape as to cover almost the entire non-display area 10, the capacitance of the area is large. In the case where the potential equalizing means as described in JP-A-57-56044 is not provided between the transparent electrodes 1 and 3 and the dummy electrode 14, high-voltage static electricity is generated during the rubbing process. The transparent electrodes 1 and 3 are liable to be charged, and a discharge is generated between the transparent electrodes 1 and 3 and the dummy electrode 14 so that the transparent electrodes 1 and 3 are likely to be electrostatically damaged. Further, when the potential equalizing means is provided between the transparent electrodes 1 and 3 and the dummy electrode 14, it is possible to eliminate the inconvenience such as the electrostatic breakdown of the transparent electrodes 1 and 3 during the rubbing process. Since the process becomes complicated and the cost of the liquid crystal display element increases, and after the potential equalizing means is separated, the large-area dummy electrode 14 is also likely to be charged with high-voltage static electricity. It is easy to cause energized air bubble failure which is a phenomenon to be destroyed.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid crystal display device which is inexpensive and hardly affected by static electricity.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method of dividing a plurality of groups into a plurality of groups.
Transparent electrode group and each upper transparent grouped
Has dummy electrodes formed in non-display areas between electrode groups
The upper electrode substrate is divided into several groups.
Transparent electrode group and each grouped lower part
Dummy electrodes formed in the non-display area between the transparent electrode groups
With a lower electrode substrate having a required cell gap.
The upper transparent electrode group formed on the upper electrode substrate
And the lower transparent electrode formed on the dummy electrode and the lower electrode substrate.
In a liquid crystal display device in which an electrode group and a dummy electrode face each other, a plurality of dummy electrodes are formed for each of the non-display regions.
Configuration. The size of the dummy electrode is
Although it can be set arbitrarily, the capacitance of each dummy electrode
Considering the amount and color unevenness, the upper transparent electrode group and the lower transparent electrode group
Approximately equal to the size of one pixel regulated by the bright electrode group
Is particularly preferred.

[0008]

When a plurality of dummy electrodes are formed in one non-display area, the area per one dummy electrode is reduced and the capacitance is reduced. In this case, defective energized bubbles due to the charging of the dummy electrode are less likely to occur, and the yield of non-defective products and the durability of the products are improved. Further, since it is not necessary to take any special means for preventing the electrostatic breakdown of the transparent electrode during the rubbing treatment, for example, the above-mentioned potential equalization means, it can be implemented at low cost.

[0009]

FIG. 1 is a plan view of a main part of a liquid crystal display device according to a first embodiment, and FIG. 2 is a cross-sectional view of the main part.
Parts corresponding to those in FIG. 7 are denoted by the same reference numerals.

As shown in these figures, the liquid crystal display device of the present embodiment has upper transparent electrodes 1 and lower transparent electrodes 3 at opposing positions on the inner surfaces of an upper electrode substrate 2 and a lower electrode substrate 4. A large number of dot-shaped dummy electrodes 14 are formed for each non-display area 10 that is not present. Other portions are formed in the same manner as the conventional liquid crystal display device shown in FIGS. The size of one dummy electrode 14 can be arbitrarily set in consideration of the capacitance and the color unevenness. For example, the size of one dummy electrode 14 is equal to the size of one pixel in the display region (0.3 to 0.3). (0.4 mm square) is particularly preferable. The dummy electrodes 14 are formed simultaneously with the transparent electrodes 1, 3 and the electrode terminals 8 by printing using a transparent conductive material such as ITO forming the transparent electrodes 1, 3 and the electrode terminals 8. These dummy electrodes 14 are formed electrically independently of each other and electrically independent of the transparent electrodes 1 and 3 and the electrode terminal 8. Further, these dummy electrodes 14 are formed to have substantially the same thickness as the transparent electrodes 1 and 3 and the electrode terminals 8 in order to prevent color unevenness of the liquid crystal display element. In addition, the method of bonding the glass substrates 2 and 4,
The method of injecting liquid crystal and the like are the same as those conventionally well-known methods, and are not the gist of the present invention, and therefore description thereof is omitted.

In the liquid crystal display device of the embodiment, since a large number of dot-shaped dummy electrodes 14 are formed for each non-display area, the area per dummy electrode is reduced, and the capacitance of the dummy electrode is reduced. can do. Therefore, it is difficult to cause the electrostatic breakdown of the transparent electrodes 1 and 3 during the rubbing process and the failure of the energized bubble due to the charging of the dummy electrode 14 during use, thereby improving the yield of non-defective products and the durability of the products. In addition, since it is not necessary to take any special means for preventing the electrostatic breakdown of the transparent electrodes 1 and 3 during the rubbing process, for example, a potential equalizing means or the like, it can be implemented at low cost.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a plan view of a main part of a liquid crystal display device according to a second embodiment, and the same reference numerals are given to portions corresponding to FIG. 1 described above.

As shown in FIG. 1, in the liquid crystal display device of this embodiment, a plurality of linear dummy electrodes 14 are formed for each non-display area 10. The rest is the same as the liquid crystal display device of the first embodiment shown in FIG. The liquid crystal display device of the present embodiment also has substantially the same effects as the liquid crystal display device of the first embodiment.

The gist of the present invention resides in that a plurality of dummy electrodes are divided and formed for each non-display area. The shape, arrangement, and the like of the dummy electrodes 14 are limited to the above embodiment. Can be set as desired. For example, in the above-described embodiment, the dummy electrodes 14 are formed at opposing positions on the inner surfaces of the upper electrode substrate 2 and the lower electrode substrate 4, respectively. However, as shown in FIG. The dummy electrode 14 may be formed only on one of the inner surfaces.

[0015]

As described above, according to the present invention,
Since a plurality of dummy electrodes are formed for each non-display area and the area per dummy electrode is reduced, the capacitance of each dummy electrode is reduced, and the electrostatic damage of the transparent electrode during the rubbing process or during use In this case, defective energized bubbles due to the charging of the dummy electrode are less likely to occur, and the yield of non-defective products and the durability of the products are improved. In addition, since it is not necessary to take any special means for preventing the electrostatic breakdown of the transparent electrode during the rubbing treatment, for example, a potential equalizing means, it is possible to implement the method at low cost.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a liquid crystal display device according to a first embodiment.

FIG. 2 is a sectional view of a main part of the liquid crystal display element according to the first embodiment.

FIG. 3 is a plan view of a main part of a liquid crystal display device according to a second embodiment.

FIG. 4 is a cross-sectional view of a main part of a liquid crystal display element according to another embodiment.

FIG. 5 is a sectional view of a main part of the liquid crystal display element.

FIG. 6 is a plan view of a main part of a liquid crystal display device having no dummy electrode.

FIG. 7 is a plan view of a main part of a liquid crystal display device according to a conventional example.

[Explanation of symbols]

 Reference Signs List 1 upper transparent electrode 2 upper electrode substrate 3 lower transparent electrode 4 lower electrode substrate 10 non-display area 14 dummy electrode

Claims (2)

(57) [Claims] 1. The method according to claim 1 , wherein the group is divided into a plurality of groups.
Transparent electrode group and each upper transparent grouped
Has dummy electrodes formed in non-display areas between electrode groups
The upper electrode substrate is divided into several groups.
Transparent electrode group and each grouped lower part
Dummy electrodes formed in the non-display area between the transparent electrode groups
With a lower electrode substrate having a required cell gap.
The upper transparent electrode group formed on the upper electrode substrate
And the lower transparent electrode formed on the dummy electrode and the lower electrode substrate.
In a liquid crystal display device in which an electrode group and a dummy electrode face each other, a plurality of dummy electrodes are formed for each of the non-display regions.
The liquid crystal display element characterized by forming the. 2. The group of claim 1, wherein the size of the dummy electrode is set to the upper transparent electrode group and the lower transparent electrode group.
A liquid crystal display element having a size substantially equal to the size of one pixel regulated by the above .