JP3819086B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly to improvement in display unevenness such as contrast and color tone due to gap unevenness in an STN (super twisted nematic) liquid crystal display device.
[0002]
[Prior art]
As shown in FIG. 6, the liquid crystal display device has a gap between a first glass substrate 2 on which a segment-side transparent electrode 1 is formed and a second glass substrate 4 on which a common-side transparent electrode 3 is formed facing each other. The peripheral portion is bonded and liquid crystal is encapsulated to form a display portion 5 composed of pixels formed by intersecting the segment side transparent electrode 1 and the common side transparent electrode 3, and each electrode has a desired voltage. Is applied to change the orientation of the liquid crystal by the generated electric field.
[0003]
In the case of manufacturing a liquid crystal display device, in order to keep the gap between the first glass substrate 2 and the second glass substrate 4 at a predetermined design value, a glass fiber of a specific diameter or a spherical substance is used as a spacer. As a sensor, the gap was managed by being distributed between both substrates. However, management of the gap which becomes a liquid crystal layer has become an important problem along with the improvement in performance of liquid crystal display devices in recent years. That is, when there is a partial gap unevenness from a TN (twisted nematic) type liquid crystal to an STN (super twisted nematic) type liquid crystal, the display becomes uneven and becomes a major factor that deteriorates the display quality. It was. Therefore, in order to improve the display quality of the liquid crystal display device, it is necessary to keep the gap uniform over the entire display portion.
[0004]
Therefore, in the invention disclosed in Japanese Patent Application Laid-Open No. 63-26631, when using a substrate on which unevenness such as an electrode is formed, an adhesive portion is formed in order to form unevenness almost evenly in at least a region related to gap formation. Crossing the feeder line is not necessary only in the design of the feeder function, and unevenness due to open circuit dummy wiring made of the same material as the feeder line is formed in an area where it is not necessary to install the feeder line. Occurrence is prevented. Therefore, the gap defined by the height of the convex portion and the spacer diameter can be formed uniformly over the entire display area.
[0005]
In addition, the invention disclosed in Japanese Utility Model Laid-Open No. 2-128128 also provides a dummy electrode which is ineffective for the substrate in order to make the gap between the substrates of the liquid crystal display device uniform, as in Japanese Patent Laid-Open No. 63-26631. Disposing in the pixel region is disclosed. FIG. 7 shows the structure of a liquid crystal display device disclosed in Japanese Utility Model Laid-Open No. 2-128128. FIG. 7A shows a portion corresponding to part B of FIG. 6, and it is necessary to show the positional relationship between the electrodes formed at the corners on the first glass substrate 2 and the second glass substrate 4. FIG. 7B is a partial plan view, and FIG. 7B is a cross-sectional view taken along the line DD of FIG.
[0006]
As can be seen from FIG. 7, in the non-effective pixel region other than the display portion composed of pixels, when there are no opposing electrodes on both substrates, dummy electrodes are formed on both substrates. That is, dummy electrodes 5a, 5b, and 5c are formed on the first glass substrate 2 on the substrate portion on which neither the segment-side transparent electrode 1 nor the common-side transparent electrode 3 is formed, and the second glass substrate 4 is damaged. -Dummy electrodes 6a, 6b, 6c are formed at positions facing the electrodes 5a, 5b, 5c. If there is an electrode only on one substrate, a dummy electrode is formed at the position of the other substrate facing the electrode. That is, dummy electrodes 7a, 7b, 7c are formed at the position of the second glass substrate 4 facing the segment side transparent electrode 1 formed on the first glass substrate 2. As a result, the gap interval between the two substrates is made constant via the dummy electrode.
[0007]
[Problems to be solved by the invention]
However, in the above prior art, when a dummy electrode is used in order to prevent the occurrence of non-uniform gaps between the substrates, after the liquid crystal display device is completed, the charge is charged after the static electricity is charged from the outside. -A new problem has arisen in which a constantly lit portion is displayed in a non-display portion. In addition, the pixel electrode portion and the dummy electrode portion of the liquid crystal display device are slightly different in color and have a problem of uneven color.
[0008]
The present invention has been made in view of the above problems, and its purpose is to make the gap between the substrates of the liquid crystal display device uniform and to display a constantly lit portion in a non-display portion due to electrostatic charge. An object of the present invention is to provide a liquid crystal display device with improved display unevenness such as color.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a first substrate on which a segment side transparent electrode is formed and a second substrate on which a common side transparent electrode is formed, and the segment side transparent electrode and the common side transparent electrode intersect. In a liquid crystal display device having a dummy electrode on the outer peripheral portion of the display unit, the display unit comprising the above-described pixels ,
A plurality of opposing dummy electrodes are formed as corner dummy electrodes on at least one of the substrates in at least one corner of the outer peripheral portion, and the corner dummy electrodes are It is formed of an electrode similar to the segment side transparent electrode or formed of an electrode similar to the common side transparent electrode and formed with an electrode width equal to or smaller than the electrode width of the segment side transparent electrode or the common side transparent electrode. The corner dummy electrode of one of the first substrate and the second substrate facing each other is connected to a transparent electrode for constituting the pixel on the same substrate, and the corner dummy electrode of the other substrate Is characterized in that the transparent electrode for constituting the pixel is in an open circuit floating state .
[0010]
Further, the dummy electrodes connected by the connecting electrode, the an outermost first electrode or the second electrode, the dummy - that is connected to the electrode and the closer electrode at the connecting electrode Features.
[0011]
Furthermore, dummy - electrode is characterized in that it is formed in small Do Kutomo one place corners of four positions of the area that can intersect first substrate and the second substrate.
[0012]
Furthermore, the electrode width of the dummy electrode connected by the connection electrode is substantially the same as the electrode width of the first electrode or the second electrode connected by the connection electrode, To do.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on examples shown in the drawings. In the figure, the same members as those of the prior art are denoted by the same reference numerals, and description thereof is omitted. FIG. 1 is a plan view showing the positional relationship of electrodes of a liquid crystal display device according to a first embodiment of the present invention. FIG. 2 is a plan view showing the positional relationship of the electrodes of the second glass substrate of FIG. FIG. 3 is an enlarged plan view of a portion A in FIG. 4 is a cross-sectional view taken along the line CC of FIG.
[0015]
Ineffective other than the display unit 5 including pixels formed by the intersection of the segment side transparent electrode 1 formed on the first glass substrate 2 and the common side transparent electrode 3 formed on the second glass substrate 4 A dummy electrode is formed in the pixel region. That is, dummy electrodes 8, 10, 12, 14 are formed at four corners on the first glass substrate 2, and dummy electrodes 8, 10, 12, 14 are formed on the second glass substrate 4. Dummy electrodes 9, 11, 13, and 15 are formed at positions facing the.
As shown in FIG. 3, in the embodiment of the present invention, the dummy electrode provided at the corner is set to be substantially the same as the electrode width or electrode pitch of the segment side transparent electrode 1.
[0016]
Further, regarding the dummy electrodes 8 and 9, as shown in the sectional view of FIG. 4, the dummy electrodes 8a, 8b, 8c and 9a, 9b, 9c are segmented as shown in the sectional view of FIG. The side transparent electrode 1 and the common side transparent electrode 3 are provided on the substrate, and the gaps between the dummy electrodes 8a-9a, 8b-9b, and 8c-9c are transparent to the segment side transparent electrode 1 and the common side transparent electrode. The distance is the same as the gap distance from the electrode 3. The dummy electrodes 8, 10, 12, and 14 on the first glass substrate 2 are connected to the electrodes on the outer side of the segment-side transparent electrode 1 and are electrically connected. As for the dummy electrode 8, each dummy electrode 8a, 8b, 8c is connected to the outer segment-side transparent electrode 1a by the connection electrode 8d. As shown in FIG. 2, the dummy electrodes 9, 11, 13, 15 on the second glass substrate 4 are not connected to the common-side transparent electrode 3 and are brought into a non-conductive open circuit floating state. ing.
[0017]
With such a configuration, in the first embodiment, the gap between the first glass substrate 2 and the second glass substrate 4 is such that the gap between the segment side transparent electrode 1 and the common side transparent electrode 3 is the display unit. In the outer periphery of the substrate, gaps having the same interval are set between the dummy electrodes 8-9, 10-11, 12-13, and 14-15. By dispersing as a material, the gap between the substrates can be made constant and uniform.
[0018]
Moreover, since the dummy electrodes 8, 10, 12, and 14 on the first glass substrate 2 are connected to the electrodes of the segment side transparent electrode 1, electrostatic discharge is applied to the dummy electrode portion from the outside after the liquid crystal display device is completed. Even if charged, discharge is possible through the segment side transparent electrode, and display quality is not deteriorated.
[0019]
Furthermore, in this embodiment, the dummy electrodes 8, 10, 12, 14 on the first glass substrate 2 are connected to the electrodes of the segment-side transparent electrode 1, respectively, and the dummy electrodes on the second glass substrate 4 are connected. 9, 11, 13, and 15 are not connected to the common transparent electrode 3 and are in an open circuit floating state.
[0020]
FIG. 5 is an enlarged plan view showing a portion corresponding to part A of FIG. 1 according to another embodiment of the present invention. The dummy electrodes are formed along the four sides of the outer peripheral part of the display part of the liquid crystal display panel. The dummy electrode on the first glass substrate 102 extends from the segment-side transparent electrode 101 constituting the pixel portion to the outer peripheral portion of the display portion 105 to form a dummy electrode 101a. Although not shown, the dummy electrode A dummy electrode facing the substrate 101a is formed on the second glass substrate 104, and the dummy electrode on the second glass substrate 104 is connected to the common-side transparent electrode 103 constituting the pixel portion on the outer periphery of the display portion 105. The dummy electrode 103a is extended to a portion, and although not shown, a dummy electrode facing the dummy electrode 103a is formed on the first glass substrate 102. Incidentally, the dummy electrodes 108 at the corners are provided at four locations with the same configuration as in the first embodiment. Further, the width of the dummy electrode formed by extending the segment side transparent electrode or the common side transparent electrode is made smaller than the width of the display part electrode of the segment side transparent electrode or the common side transparent electrode, respectively. The width of the segment-side transparent electrode is about 120 μm to 200 μm, the width of the common-side transparent electrode is about 300 μm, and the width of the dummy electrode formed by extending this is suitably about 90% of each. If the width of the dummy electrode is too small, it is not preferable because it is clearly not distinguished from the display portion in a non-lighting state. In addition, the area of a pixel is about 300 micrometers x 120 micrometers-200 micrometers from the width | variety of said segment side transparent electrode and common side transparent electrode.
[0021]
In this embodiment, since dummy electrodes are formed on all four sides of the outer peripheral piece of the display unit 105, the effect of making the gap distance between the substrates constant and uniform can be further enhanced. In addition, the width of the dummy electrode formed by extending the segment side transparent electrode or the common side transparent electrode is smaller than the width of the segment side transparent electrode or the common side transparent electrode, respectively. A short circuit between the electrodes at the electrode portion can be prevented.
As described above, the present invention includes the first substrate in which the segment-side transparent electrode is formed on one substrate, and the second substrate in which the common-side transparent electrode is formed on the other substrate, and the first substrate and the first substrate A liquid crystal display device in which liquid crystal is sealed between two substrates, and the first substrate and the second substrate in a region other than a display portion including pixels in which the segment side electrode and the common side electrode intersect. The dummy electrodes on the first substrate are connected to any one of the segment-side transparent electrodes, and the dummy electrodes on the second substrate are The dummy electrode on the second substrate is connected to any one of the common-side transparent electrodes, and the dummy electrode on the first substrate is an open circuit. . Further, the dummy electrode on the first substrate or the second substrate is connected to the outermost electrode of the segment side transparent electrode or the common side transparent electrode and close to the dummy electrode. Further, the dummy electrode is formed in at least one of the four corners of the region formed by the intersection of the first substrate and the second substrate. Furthermore, the dummy electrode is formed along four sides of the outer peripheral portion of the display unit. Furthermore, the width of the dummy electrode formed by extending the segment side transparent electrode on the first substrate on the outer periphery of the display unit is smaller than the width of the display unit electrode of the segment side transparent electrode, The dummy electrode formed by extending the common-side transparent electrode on the second substrate has a width smaller than that of the display portion electrode of the common-side transparent electrode.
[0022]
【The invention's effect】
As is apparent from the above description, according to the present invention, the dummy electrode is provided on the substrate to make the gap between the substrates of the liquid crystal display device uniform, and one of the dummy electrodes is connected to the pixel electrode. However, it is possible to eliminate display unevenness such as color by making the other open circuit, that is, floating.
[Brief description of the drawings]
FIG. 1 is a plan view showing an arrangement relationship of electrodes of a liquid crystal display device according to a first embodiment of the present invention.
2 is a plan view showing an arrangement relationship of electrodes of a second glass substrate of FIG. 1. FIG.
FIG. 3 is an enlarged plan view of a part A in FIG. 1;
4 is a cross-sectional view taken along the line CC in FIG. 3;
5 shows another embodiment of the present invention, and is a partially enlarged plan view corresponding to part A in FIG. 1. FIG.
FIG. 6 is a plan view showing an electrode arrangement relationship of a conventional liquid crystal display device.
7 (a) is an enlarged plan view of a main part showing the electrode arrangement relationship of a portion corresponding to the portion B in FIG. 6, and FIG. 7 (b) is a sectional view taken along the line DD in FIG. 7 (a). It is.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,101 Segment side transparent electrode 2,102 1st glass substrate 3,103 Common side transparent electrode 4,104 2nd glass substrate 5,105 Display part 8, 10, 12, 14 Dummy on 1st glass substrate -Electrodes 9, 11, 13, 15 Dummy electrodes on the second glass substrate

Claims (1)

A first substrate on which a segment-side transparent electrode is formed;
And a second substrate on which a common-side transparent electrode is formed
A display unit comprising pixels in which the segment-side transparent electrode and the common-side transparent electrode intersect
In the liquid crystal display device having a dummy electrode on the outer peripheral portion of the display unit,
A plurality of opposing dummy electrodes are formed as corner dummy electrodes on at least one of the substrates in at least one corner of the outer peripheral portion.
The corner dummy electrode is formed of an electrode similar to the segment side transparent electrode or an electrode similar to the common side transparent electrode.
And it is formed with an electrode width equal to or smaller than the electrode width of the segment side transparent electrode or the common side transparent electrode.
The corner dummy electrode of one of the first and second substrates facing each other is connected to a transparent electrode for constituting the pixel on the same substrate, and the corner dummy electrode of the other substrate is A liquid crystal display device characterized in that a transparent electrode for constituting a pixel is in an open circuit floating state .

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