JP2002174814A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device in which a flattening film or the like to prevent exposure of color filters is not necessary although a slit is formed in a counter electrode. SOLUTION: A liquid crystal 12 is sealed between a pair of substrates 1, 7, pixel electrodes 4 are formed on one substrate 1 and a counter electrode and color filters 9 are formed on the other substrate 7. A slit 13 is formed in every pixel on the counter electrode 10. In the portion of the slit, the color filter 9 is removed and edges of the color filter 9 are covered with the counter electrode 10.

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 in which a slit is formed in a counter electrode to improve viewing angle characteristics.

[0002]

2. Description of the Related Art Although a TN mode has been put to practical use in a liquid crystal display device, the TN mode has a problem that a viewing angle is narrow. For this reason, systems having excellent viewing angle characteristics, such as the IPS system and the VA system, are disclosed in JP-A-6-194657 and JP-A-7-194657.
As disclosed in Japanese Patent No. 43719 and Japanese Patent No. 3011720, there has been proposed a device in which a slit is provided in a counter electrode arranged to face a pixel electrode to form a plurality of viewing angle directions in one pixel.

A liquid crystal display device in which a slit is formed in a counter electrode will be described with reference to FIG. FIG. 4 is a schematic sectional view of a conventional liquid crystal display device when a voltage is applied. 100 is a transparent substrate such as a glass substrate, 101 is a signal line formed on the substrate 100, 102 is a pixel electrode provided for each pixel, and 103 is an alignment film laminated on the substrate 100.
104 is a transparent substrate opposed to the substrate 100, 10
5 is a light-shielding film disposed between pixels, 106 is a color filter corresponding to each pixel, 107 is a color filter 106
Is a counter electrode provided with a slit 111 at a portion facing the center of the pixel electrode 102, and 109 is an alignment film covering the counter electrode 108 and the flattening film 107. The liquid crystal 1 is provided between the pair of substrates 100 and 104.
10, the arrangement state changes according to the voltage applied to the pixel electrode 102. For example, when the liquid crystal 110 has a negative dielectric anisotropy and the alignment films 103 and 109 are subjected to a vertical alignment process, when no voltage is applied, the liquid crystal molecules 110 are affected by the alignment films 103 and 109 to be in a vertical alignment. During the application of an electric field, the liquid crystal molecules 110
It tilts in the horizontal direction under the influence of the electric field generated between them. At this time, since the slit 111 is formed in the opposing electrode 108, the substrate 10 is formed as shown by a dotted line in FIG.
An electric field is generated in an oblique direction with respect to 0 and 104, and regions having different inclination directions of liquid crystal molecules are formed in one pixel.

[0004]

If the slit 111 is not formed in the opposing electrode 108, the flattening film 107 may not be provided.
Is formed, the flattening film 1 is formed on the color filter 106.
For example, a film covering the color filter 106 such as 07 is required. For example, when the flattening film 107 is not provided at the slit 111, the color filter 106 comes into contact with the liquid crystal via the alignment film 109 at the slit 111, and the components of the color filter 106 pass through the alignment film 109 and the liquid crystal 110
Will melt into For this reason, a problem such as contamination of the liquid crystal 110 occurs, and the display quality is deteriorated. Therefore, the components of the color filter 106 are prevented from dissolving into the liquid crystal 110 by laminating the flattening film 107 on the color filter 106 in the slit 111 portion. When the slit 111 is formed in the counter electrode 108 in this manner, a flattening film 107 or the like is required at the slit 111 portion, but the number of manufacturing steps for laminating the flattening film 107 increases.

Accordingly, the present invention proposes a liquid crystal display device in which a slit is formed in a counter electrode without providing a flattening film or the like.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a liquid crystal sealed between a pair of substrates, a pixel electrode formed for each pixel on one substrate, and a liquid crystal formed on the other substrate. A color filter disposed opposite to the pixel electrode, and a counter electrode laminated on the color filter, and a slit formed in the counter electrode according to each pixel,
In the slit portion, the color filter is removed, and an end of the color filter is covered with the counter electrode. By removing the color filter in the slit part, the counter electrode can also be used as a film that covers the color filter, and the components of the color filter dissolve into the liquid crystal without specially forming a film that covers the color filter such as a flattening film. Can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of the first substrate side, and FIG. 2 is a schematic sectional view taken along line AA of FIG.

Reference numeral 1 denotes a transparent first substrate such as a glass substrate. On this first substrate 1, a scanning line 2 and a signal line 3 are arranged in a matrix, and an area surrounded by the scanning line 2 and the signal line 3 is provided. The pixel electrode 4 is disposed at the center. A TFT 5 (thin film transistor) is formed at the intersection of the scanning line 2 and the signal line 3,
The gate electrode of the TFT 5 is connected to the scanning line 2, the source electrode of the TFT 5 is connected to the signal line 3, and the drain electrode of the TFT 5 is connected to the pixel electrode 4. Reference numeral 6 denotes an alignment film that has been subjected to a vertical alignment process, and is stacked on the pixel electrode 4.

Reference numeral 7 denotes a transparent second substrate such as a glass substrate. On the second substrate 7, a light shielding film 8, a color filter 9, a counter electrode 10, and an alignment film 11 are sequentially laminated. The counter electrode 10 is provided with a slit 13 for regulating the tilt direction of the liquid crystal molecules 12 when a voltage is applied. In the present invention, the color filter 9 corresponding to the slit 13 is removed. FIG. 3 is a schematic diagram showing the positional relationship between the light-shielding film 8 and the slit 13. The dotted line indicates the pixel electrode 4. As shown in FIG. 3, the light-shielding film 8 is formed in a portion facing the scanning line 2 and the signal line 3 between each pixel and in a slit 13 portion. Irregular disclination is likely to occur in the slit 13 due to the presence of the liquid crystal molecules 12 inclined in different directions. In addition, since the color filter 9 in the slit 13 is removed, white light is transmitted therethrough when a voltage is applied. Display quality is degraded. Therefore, by providing the light shielding film 8 in the slit 13, adverse effects on display can be reduced. Further, even when the light-shielding film 8 is formed in the slit 13, the light-shielding film 8 can be formed in the same step as the light-shielding film 8 between pixels, so that it can be easily manufactured without increasing the number of manufacturing steps.

[0010] The color filter 9 has RGB components corresponding to each pixel.
Are arranged in stripes in this order, and a slit 13 having the shape shown in FIG. 3 is formed for each pixel. The counter electrode 10 is I
It is formed of TO or the like, and covers the entire surface of the color filter 9. A slit 13 is also formed in the counter electrode 10,
By removing the color filter 9 in the slit 13 portion, it is possible to cover up to the end of the color filter 9 with the counter electrode 10, and the components of the color filter 9
2 can be prevented. A vertical alignment process is performed on the alignment film 11 that covers the opposing electrode 10 and the light-shielding film 8 in the slit 13.

A liquid crystal 12 having a negative dielectric anisotropy is sandwiched between the substrates 1 and 7, and when no voltage is applied, the alignment films 6, 1
Vertical arrangement is performed under the action of 1. When a voltage is applied to the pixel electrode 4, an electric field is generated between the pixel electrode 4 and the counter electrode 10, and the liquid crystal molecules 12 are inclined from the vertical direction to the horizontal direction by the electric field. At this time, an electric field is generated in an oblique direction with respect to the substrates 1 and 7 at the periphery of the pixel electrode 4 and the slit 13 of the counter electrode 10 as shown by the dotted line in FIG. Direction is regulated. In the counter electrode 10 in the slit 13 portion, an electric field is generated from the end to the pixel electrode 4 while spreading toward the center of the slit 13, and the liquid crystal molecules 12 located on the left side of the slit 13 are tilted clockwise as shown in FIG. Then, the liquid crystal molecules 12 located on the right side of the slit 13 tilt counterclockwise. The direction of inclination of the liquid crystal molecules 12 near the slit 13 affects the surrounding liquid crystal molecules 12, and each liquid crystal molecule 12 is inclined in substantially the same direction as the adjacent liquid crystal molecules 12. Then, the liquid crystal molecules 12 in the regions adjacent to each other with the slit 13 interposed therebetween are inclined in the opposite directions. In this embodiment, since one pixel is divided into four regions by the slits 13, the liquid crystal molecules 12 in each region are inclined by the inclination. The viewing angle in the direction corresponding to the direction is improved, and the liquid crystal display device has a wide viewing angle.

The present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention. For example, in this embodiment, a VA mode liquid crystal display device has been described.
For a liquid crystal display device in which a slit is formed in the opposite electrode, T
It is also effective for N mode.

[0013]

According to the present invention, the color filter is removed from the slit portion of the counter electrode and the end of the color filter is covered with the counter electrode. By removing the color filter in the slit portion in this manner, it becomes possible to cover the color filter to the end with the counter electrode, and the step of forming a film that prevents the components of the color filter from dissolving in the liquid crystal is omitted. can do.

Further, since the light-shielding film is provided in the slit portion, the influence on the display quality due to irregular disclination caused by disorder of the arrangement of the slit portion and white transmitted light not passing through the color filter is reduced. And high-quality display can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a first substrate side of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view when a voltage is applied to the liquid crystal display device according to the embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a positional relationship between a light shielding film and a slit according to the embodiment of the present invention.

FIG. 4 is a schematic sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

 2 Gate line 3 Source line 4 Pixel electrode 9 Color filter 10 Counter electrode 12 Liquid crystal molecule 13 Slit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Kase 3-201 Minamiyoshikata, Tottori-shi, Tottori Sanyo Electric Co., Ltd. (72) Inventor Yoshitaka Mori 3-201 Minamiyoshikata, Tottori-shi, Tottori Sanyo Tottori Inside Electric Co., Ltd. (72) Inventor Shinichiro Tanaka 3-201 Minamiyoshikata, Tottori City, Tottori Pref. 5C094 AA43 AA45 BA03 BA43 CA19 CA24 EA04 EA07 ED02 ED15

Claims (4)

[Claims] A liquid crystal sealed between a pair of substrates; a pixel electrode formed for each pixel on one substrate; a color filter formed on the other substrate and arranged to face the pixel electrode; A counter electrode laminated thereon, and a slit formed in the counter electrode in accordance with each pixel, wherein the slit portion is removed and the end of the color filter is covered with the counter electrode. Liquid crystal display device. 2. A liquid crystal having a negative dielectric anisotropy is used as the liquid crystal, and a vertical alignment film is laminated on the two substrates. When no voltage is applied, the liquid crystal molecules are vertically aligned. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal is inclined in a horizontal direction. 3. The liquid crystal display device according to claim 1, wherein said slit portion regulates a tilt direction of liquid crystal molecules when a voltage is applied. 4. The liquid crystal display device according to claim 1, wherein a light-shielding film is formed in a slit portion on the other substrate.