JP2000171808A - Liquid crystal display - Google Patents

Abstract

(57) [Object] To provide a horizontal electric field type liquid crystal display device capable of displaying a high quality image by eliminating light leakage due to a spacer and suppressing disturbance of an electric field between electrodes. Kind Code: A1 At least two or more types of color filters FIL having different colors for color display on one substrate SUB2.
(R), FIL (G), and a black matrix BM interposed between the color filters, and the other substrate S
UB1 has electrode groups PX, CT, CT1, for pixel selection.
A liquid crystal layer LC made of a liquid crystal composition having a dielectric anisotropy sandwiched between a pair of substrates, and polarizing plates POL1, POL2 on at least one outer surface of the pair of substrates. A liquid crystal display device comprising: a liquid crystal panel formed by laminating the electrodes; and a driving unit for applying a driving voltage for display to the electrode group, while bridging a gap between opposing inner surfaces of the pair of substrates, A projection SP1 formed on one substrate SUB2 side and having a specific resistance of less than 10 ⁸ Ω · cm, and a specific resistance formed on the other substrate SUB1 side being 10 ⁸ Ω · cm.
A spacer SP formed by contacting each of the top surfaces with the above-mentioned protrusion SP2 was provided.

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 liquid crystal display device in which a substantially parallel electric field is applied to a substrate to control a liquid crystal molecular axis in a plane of the substrate. And an active matrix type liquid crystal display device.

[0002]

2. Description of the Related Art An active matrix type liquid crystal display device using an active element typified by a thin film transistor (TFT) as a switching element for selecting a pixel is characterized in that it is thin and lightweight, and has a high image quality display comparable to a cathode ray tube. In that it is widely used as a display terminal for various electronic devices such as OA equipment.

[0003] There are roughly two types of display methods of this liquid crystal display device. One is a liquid crystal (hereinafter, also referred to as a liquid crystal layer) formed of two substrates on each of which a transparent electrode for pixel selection is formed.
A voltage is applied between the transparent electrodes to control the molecular orientation of the liquid crystal, and the light transmitted through the transparent electrode and incident on the liquid crystal layer is modulated and displayed. Used in products. The other is to form an electrode group for pixel selection only on one substrate and control the parallel direction of the liquid crystal molecules constituting the liquid crystal layer by an electric field substantially parallel to the substrate surface,
A method of performing display by modulating light incident on the liquid crystal layer from the gap between the electrode groups (hereinafter, referred to as a lateral electric field method: IPS method).
This is a promising technology for an active matrix type liquid crystal display device having a feature that the viewing angle is extremely wide.

In a liquid crystal display device for performing color display, a red (R), green (G), and blue (B) colored layer (color filter FIL) and a black matrix BM, which is a light shielding layer, are provided on one of two substrates. A transparent electrode layer made of ITO or the like is formed. Hereinafter, this substrate is also referred to as a color filter substrate substrate or a counter substrate.

A color filter F is provided on a color filter substrate.
In some cases, a protective film (overcoat) OC for protecting the IL and the black matrix is coated. The thin film transistor TFT serving as a switching element generally uses amorphous silicon AS as a semiconductor.

In order to keep the gap (cell gap) between the two substrates constant, plastic beads or the like having a substantially uniform particle size are scattered between the substrates.

The prior art relating to the in-plane switching mode liquid crystal display device is disclosed, for example, in Japanese Patent Publication No. 5-505247 or Japanese Patent Publication No. Sho 63-2190.
7 and JP-A-6-160878.

FIG. 10 is a sectional view of the vicinity of an electrode of one pixel of a liquid crystal panel constituting a liquid crystal display device of a horizontal electric field type, and a sectional view of a peripheral portion of a substrate. On the color filter substrate SUB2 side, which is one of the substrates with respect to the liquid crystal layer LC, a pattern of a color filter FIL and a light-shielding black matrix BM is formed. The black matrix B for shading
It is also possible to form the M pattern on the active matrix substrate SUB1 side.

An active matrix substrate SUB1, which is the other substrate, has a thin film transistor TFT, a storage capacitor Cstg (not shown), and an electrode group CT for pixel selection.
(Counter electrode: common electrode), PX (pixel electrode) and the like are formed. In addition, the configuration is such that the electric field E formed between the pixel electrode PX and the counter electrode CT controls the orientation direction of the molecules constituting the liquid crystal LC.

An active matrix substrate SUB1 (hereinafter also referred to as an electrode substrate) and a color filter substrate SU
Alignment films ORI11 and ORI12 for controlling the initial alignment of the liquid crystal are provided on the inner surface (the liquid crystal LC side) of each of B2, and the polarizing axes are provided on the outer surfaces of the transparent glass substrates SUB1 and SUB2. Are provided orthogonally (crossed Nicols arrangement). The periphery of the two substrates is sealed with a sealing material.

FIG. 11 is a schematic explanatory diagram of a peripheral circuit of a liquid crystal display device of a horizontal electric field type. An active matrix substrate, which is the other substrate of the liquid crystal panel, has an image display section composed of a group of a plurality of pixels arranged in a matrix, and each pixel is provided by a backlight arranged at the back of the liquid crystal panel. It is configured so that the transmitted light can be modulated independently.

An active pixel area AR is provided on an active matrix substrate SUB1, which is one of the components of the liquid crystal panel.
The gate signal line GL and the counter voltage signal line CL, which extend in the x direction (row direction) and are arranged in parallel in the y direction (column direction), extend in the y direction while being insulated from each other, and are arranged in parallel in the x direction. The formed drain signal line DL is formed.

Here, a unit pixel is formed in a rectangular area surrounded by each of the gate signal line GL, the counter voltage signal line CL, and the drain signal line DL.

The liquid crystal panel is provided with a vertical scanning circuit V and a video signal driving circuit H as external circuits, and the vertical scanning circuit V sequentially supplies a scanning signal (voltage) to each of the gate signal lines GL. The video signal drive circuit H supplies a video signal (voltage) to the drain signal line DL in accordance with the timing.

The vertical scanning circuit V and the video signal driving circuit H are supplied with power from the liquid crystal driving power supply circuit POW, and image information from the CPU 1 is transmitted to the controller CO.
The display data and the control signal are separately input according to NT.

In the above-described in-plane switching mode liquid crystal display device, a large number of wirings are provided on the other substrate (active matrix substrate), and electric signals are transmitted through the wirings. . Therefore, the electric field applied to the liquid crystal is affected by the unnecessary electric field, and an appropriate electric field is not applied to the liquid crystal.

FIG. 12 is a schematic sectional view for explaining an example of the arrangement of electrodes constituting one pixel of a liquid crystal panel constituting a conventional in-plane switching type liquid crystal display device. The active matrix substrate SUB1 has pixel electrodes PX, counter electrodes CT1 and CT2,
A drain electrode SD2, an insulating film PSV, an alignment film ORI1, etc. are formed, and a black matrix BM, color filters FIL (R), FIL are provided on the color filter substrate SUB2.
(G), FIL (B) (not shown), an overcoat film OC, an alignment film ORI2, and the like are formed. The liquid crystal LC is sealed in the gap between the two substrates. Note that P
L1 and POL2 are polarizing plates, E is an electric field for selecting a pixel, E ′
Indicates an unnecessary electric field.

When this pixel is selected, the pixel electrode PX
An electric field E is formed between the counter electrode CT1 and the electric field E.
As a result, the orientation of the liquid crystal LC is controlled, and a so-called lighting state is achieved. At this time, since there is a potential difference between the adjacent counter electrode CT2, an undesired interference electric field E 'is formed therebetween. As a result, an appropriate electric field is not applied to the liquid crystal of the selected pixel.

For a method of applying an appropriate electric field to the liquid crystal without causing electric fields applied in parallel to the substrate to interfere with each other, and a means for improving image quality accompanying the method, see, for example, JP-A-6-160878 and JP-A-6-160788. This is disclosed in JP-A-9-120061.

[0020]

As described above, in a horizontal electric field type liquid crystal display device, a large number of wirings are provided on an active matrix substrate and electric signals are applied, so that electric fields interfere with each other. Therefore, the electric field applied to the liquid crystal may be affected by an unnecessary electric field, and an appropriate electric field may not be applied to the liquid crystal.

Further, the voltage applied to the liquid crystal may fluctuate due to unnecessary electric capacitance generated between the electrodes. Such a phenomenon causes the display quality of the liquid crystal display device to deteriorate.

In particular, an electric field generated from a video signal electrode transmitting a signal to each pixel having an active element such as a thin film transistor TFT affects an electric field between a pixel electrode for operating a liquid crystal and a common electrode. The potential of the video signal electrode constantly changes during the frame period because the video signal propagates. For example, if a pixel electrode (potential is in a floating state when the active element is turned off) is adjacent to the video signal electrode, the potential fluctuates on the video signal electrode, and a streak parallel to the video signal electrode called smear, which is a crosstalk phenomenon. It is known that unevenness such as the shadow of the image occurs.

In order to suppress this phenomenon, there is a technique of arranging a common electrode to which a potential is constantly supplied from the outside as the nearest electrode of the video signal electrode (Japanese Patent Laid-Open No. 6-46916).
No.). However, there is a problem that the technique disclosed in this publication alone does not always provide a sufficient electric field shielding effect, and smear is generated.

It is expected that if the wiring width of the common electrode is increased, the shielding effect is enhanced and the smear can be suppressed. However, increasing the wiring width decreases the aperture ratio of the liquid crystal display device. As a countermeasure against this, Japanese Patent Application Laid-Open No. 9-120061 discloses a light shielding film provided in parallel with a video signal electrode and having the light shielding film made conductive.

However, the portion formed on the color filter as the light shielding film is not limited to the portion parallel to the video signal electrode. In the lateral electric field method, the electric field applied between the video signal electrode and the common electrode has a problem that the electric field is absorbed by the light-shielding film if the light-shielding film immediately above has high conductivity. It is necessary to form two types of light-shielding films, a portion that needs to have conductivity and another portion. Therefore, the manufacturing process of the color filter becomes complicated.

In a liquid crystal display device, it is important to keep the cell gap (d) between opposing substrates of the liquid crystal panel constant. In a conventional liquid crystal display device, for example, a large number of transparent spherical spacers are scattered between substrates.

If the cell gap d changes at each position on the substrate surface, the path length difference Δn · d of the liquid crystal layer at each position (birefringence Δn of the liquid crystal layer and the thickness of the liquid crystal layer, ie, the cell gap) d). Since this change in Δn · d changes the optical response speed and transmittance of the liquid crystal, when the cell gap d at each position on the substrate surface is not uniform, the contrast ratio and chromaticity of the display screen are changed. And the display quality is deteriorated such that the uniformity of the screen cannot be maintained.

In order to obtain a uniform cell gap, it is sufficient to increase the amount of spacers to be scattered. However, it is difficult to disperse the spacers, and several spacers are scattered in a lump.
Since this results in display failure, it is not possible to disperse too much.

Further, in the method by spraying, since the spacers are arranged at random positions, they are present at various uneven positions on the substrate, and there is a limit in obtaining a uniform cell gap. Furthermore, the arrangement of the liquid crystal molecules near the spacer is in a disturbed state, and light leakage occurs in a portion where the liquid crystal arrangement is disturbed by the spacer existing in the display region, and the light leakage lowers the black level. There is a problem that the contrast is reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art, to eliminate light leakage due to spacers, and to suppress disturbance of the electric field between the electrodes, thereby enabling a high-quality image display with a high-quality image display. It is to provide a liquid crystal display device.

[0031]

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention is characterized by having the following constitutions (1) to (4).

(1) At least one of a pair of transparent substrates has at least two or more kinds of color filters having different colors for color display and a black matrix interposed between the color filters. An electrode group for pixel selection is formed on the other of the substrates, and a liquid crystal layer made of a liquid crystal composition having a dielectric anisotropy sandwiched between the pair of substrates, and at least one of the pair of substrates A liquid crystal display device comprising: a liquid crystal panel having a polarizing plate laminated on an outer surface thereof; and driving means for applying a driving voltage for display to the electrode group, wherein a liquid crystal panel is provided between the opposing inner surfaces of the pair of substrates. In addition to bridging the gap, a spacer having a specific resistance on the one substrate side smaller than a specific resistance on the other substrate side is provided.

(2) The spacer in (1) was formed by joining the top surfaces of the projections formed on each of the pair of substrates.

[0034] (3) (1) or (2) the specific resistance of the one substrate side of the spacer is less than 10 ⁸ Ω · cm in specific resistance of the other substrate side is set to 10 ⁸ Ω · cm.

(4) The projection on the one substrate side of the spacer in (2) or (3) is formed of an organic polymer material containing particles of metal or carbon, and the projection on the other substrate is an organic high material. It was formed of a molecular insulating material.

The spacer according to the present invention is a member which is formed immediately below the black matrix and has a partition shape formed continuously on the side surface of the pixel region along the black matrix matrix or a columnar shape having one or more columns. The partition walls or the columnar spacers are formed by joining the top surfaces of the projections formed fixedly between the substrate and the color filter substrate. It is created by a process of forming an insulating film and the like on the inner surfaces of these substrates. On the projection side of the spacer on the color filter substrate side, a portion having a lower specific resistance than the projection on the active matrix substrate side is provided.

By adopting each of the above-mentioned structures, a member that absorbs an unnecessary interference electric field can also be used as a spacer, so that only one light-shielding film is required, and a color filter substrate (one substrate) side is used. Since the height of the spacer can be arbitrarily adjusted, it is easy to control the amount of electric field absorption.
Further, since there is no need to disperse the spherical spacer as in the related art, the problem of light leakage does not occur.

Unlike the conventional dispersion of spherical spacers, the spacer can be formed at a desired position avoiding the pixel region, so that the cell gap can be easily controlled. Further, by making the top surface of the projection formed on each substrate a planar structure, the contact area between the opposing substrates can be increased, and the uniformity of the cell gap can be improved by dispersing the pressure applied to the spacer. . Furthermore, since the spacer has a two-layer structure, the height of each projection can be suppressed to a value equal to or less than the height of the cell gap, rubbing of the alignment film becomes easy, and uneven alignment around the spacer is reduced. can do.

The member for absorbing the unnecessary electric field may be a conductor such as a metal. In such a case, a conductor is disposed only in a portion facing the pixel electrode (video signal electrode), and an insulating material is provided to cover the conductor. It is covered with a light-shielding film with high properties. At this time, by configuring the conductor to have the same potential as the potential of the counter electrode, the electric field shielding effect can be further increased.

Further, as the insulating light-shielding film, an organic polymer material containing conductive particles such as metal and carbon is used, and the specific resistance can be adjusted by adjusting the amount of the conductive particles. it can.

[0041]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view of one pixel of a liquid crystal panel for explaining a first embodiment of a liquid crystal display device according to the present invention, and FIG. 2 is a sectional view taken along line 1-1 'of FIG. AS is non-condensed silicon (a-silicon), TFT is a thin film transistor, Cstg is a storage capacitor, CL is a counter voltage signal line, CT, CT1, and CT2 are counter electrodes, GL is a scanning signal line, GT is a gate electrode, and PX is a gate electrode. A pixel electrode, SD1 is a source electrode, SD2 is a drain electrode, and SP is a spacer.

In this embodiment, the spacer SP is connected to the video signal line DL.
In almost the area immediately above the (drain electrode SD2), the projection SP1 on the electrode substrate (active matrix substrate) side and the projection SP2 on the counter substrate (color filter substrate) side are provided in a partition shape in which the top surfaces of the projections SP2 are in contact with each other. . The projection SP1 on the color filter substrate side is made of a conductive material, and the projection SP2 on the active matrix substrate side is made of the same material as the insulating film PSV.

Therefore, the pixel electrode PX and the common electrode CT
2 is weakened by the drain electrode SD2 and further absorbed by the projection SP1 on the color filter substrate side, so that no crosstalk occurs. In addition, the thickness of the liquid crystal LC can be controlled by the spacer SP, and it is not necessary to use a conventional spherical spacer (plastic bead), and light from the periphery of the spacer, which is likely to be generated when the spherical spacer is used. A decrease in contrast due to leakage and a display defect due to uneven distribution of spacers do not occur.

As a measure of the conductivity of the projection SP1 on the counter substrate side, smear as a crosstalk phenomenon can be reduced by setting the specific resistance to less than 10 ⁸ Ω · cm.

In the lateral electric field method, electrodes are basically formed only on the substrate side on which the active elements are mounted.
Then, since the electric field is applied to the substrate in a substantially parallel direction,
The conductor on the counter substrate hinders the formation of an electric field for pixel selection.

Therefore, when the black matrix BM is provided on the counter substrate side, it is necessary that the material is not a metal but an insulator which does not affect the applied voltage.

The present inventors have made it possible to assist the shielding effect of the unnecessary electric field of the common electrode CT2 adjacent to the video signal electrode SD2 by setting the specific resistance of the projection SP1 on the counter substrate side to less than 10 ⁸ Ω · cm. I found it. This is based on the experimental result that an insulator having a specific resistance of the projection SP1 of less than 10 ⁸ Ω · cm absorbs an electric field even though it is an insulator.

FIG. 3 is a diagram showing the result of an experiment on the relationship between the specific resistance of the black matrix and the driving voltage according to the first embodiment of the present invention, and the structure of the liquid crystal cell used in this experiment.
(B-1) of (b) is a plan view of the electrode substrate, and (b-2) is a cross-sectional view taken along line AA 'of (b-1).

In this experiment, an opposing substrate in which a black matrix BM was formed on an electrode substrate (corresponding to an active matrix substrate) I on which comb-shaped electrodes EDc were formed as shown in (b-1) of FIG. A test sample in which II was superimposed (corresponding to a color filter substrate) and liquid crystal was sealed in the gap between the two was used.

Using this test sample, the drive voltage at spot a, which is not affected by the black matrix BM, and the drive voltage at spot b, which may be affected by the black matrix BM, were measured and compared. As a result, the specific resistance of the material of the black matrix BM is 10 ⁸ Ω · cm.
It was found that the drive voltage increased when the value was less than the above. That is,
It has been demonstrated that even an insulator having a specific resistance of less than 10 ⁸ Ω · cm absorbs an electric field. Therefore, the specific resistance of the material of the black matrix BM is 10 ⁸ Ω · c.
By using an insulator less than m, an effect of shielding an unnecessary electric field can be obtained.

The projection SP on the electrode substrate shown in FIG.
2 has a specific resistance of 10 ⁸ Ω · cm or more, and the drain electrode S
By arranging it at some distance from D2, it is possible to prevent the electric field between the pixel electrode PX and the common electrode CT1 used for display from being affected.

The specific resistance of the insulator can be controlled by dispersing metal particles or carbon in a high-molecular-weight organic material. By adjusting the content thereof, it is possible to adjust the specific resistance of the insulator. it can.

FIG. 4 is a plan view of a liquid crystal display device according to a second embodiment of the present invention in the vicinity of one pixel of a liquid crystal panel. The cross section along the line 1-1 'in FIG. 4 is the same as that in FIG.

In the first embodiment, the spacers SP are formed in the form of partitions arranged immediately above the video signal lines and directly below the black matrix BM. However, the spacers SP of the present embodiment are arranged in the same positions as in the first embodiment. Similar to the first embodiment, except that a plurality of columnar spacers SP are arranged instead of a single partition.

The structure of this spacer is the same as that shown in FIG.
1 and a projection SP2 formed on the color filter substrate side. According to this embodiment, in addition to the same effect as the first embodiment, the liquid crystal flows between the columnar spacers SP when the liquid crystal is injected into the opposing gap between the active matrix substrate and the color filter substrate. Has an effect that the injection of sapphire becomes easy.

FIG. 5 is a plan view of a liquid crystal display device according to a third embodiment of the present invention in the vicinity of one pixel of a liquid crystal panel.
FIG. 6 is a sectional view taken along line 1-1 ′ of FIG.

In the first and second embodiments, the spacers SP are placed just above the video signal lines in the black matrix BM.
The spacer SP of this embodiment has a protrusion SP1 on the active matrix substrate side similar to that of the first embodiment shown in FIGS. 1 and 2. Projection S formed on color filter substrate side
P2 is different from the first and second embodiments in that the height of both sides of the pixel of the black matrix BM is increased, and a projection SP2 made of a material having a specific resistance of less than 10 ⁸ Ω · cm is formed on the top surface thereof.

According to this embodiment, in addition to the same effects as those of the first embodiment, the thickness and width of the projection SP2 are arbitrarily set so as to perform optimal electric field absorption according to the magnitude of crosstalk. It has the effect of being able to

FIG. 7 is a plan view of a liquid crystal display device according to a fourth embodiment of the present invention in the vicinity of one pixel of a liquid crystal panel. This embodiment is different from the third embodiment in that the entire thickness of the black matrix BM is increased, but the height of only the central portion, that is, the portion corresponding to the drain electrode SD2 is increased. According to this embodiment, the same effects as in the first embodiment can be obtained.

The height of the black matrix BM in the third and fourth embodiments can be discontinuously formed so as to form a columnar spacer as shown in FIG. Thereby, the same effect as in the second embodiment can be obtained.

Next, an example of a method for manufacturing a liquid crystal display device of the present invention will be described with reference to the liquid crystal display device of the first embodiment.

FIG. 8 is a plan view showing the structure near one pixel of the liquid crystal panel described in the first embodiment which constitutes the liquid crystal display device according to the present invention.

First, similarly to the process of forming a general thin film transistor, the thickness is 0.7 mm or 1.1 mm.
Thin film transistor TF made of amorphous silicon AS by repeating film formation and patterning on a glass substrate
An electrode group such as T, storage capacitor Dstg, comb-shaped pixel electrode PX, source electrode SD1, and counter electrode CT is formed.

A video signal wiring DL for applying a predetermined voltage to the above-mentioned electrode group via the thin film transistor TFT, a drain electrode SD2, a counter voltage signal line CL, a plurality of scanning signal lines GL for controlling conduction of the thin film transistor TFT, and a gate electrode. GTs are formed in a lattice shape. Thin film transistor T
The FT, each electrode group and each wiring are covered with an insulating film GI (FIG. 2) and a protective film PSV.

Next, a transparent ultraviolet curable resin resist is applied to the entire surface, and ultraviolet rays are irradiated to the positions where the spacers SP are to be formed through a photomask having a desired opening pattern, developed, and post-baked to form the projections SP2. To form
Since the lower side of the projection SP2 is almost flat, the bottom and top of the projection SP2 have substantially the same area. In the ultraviolet irradiation step, the surface of the ultraviolet-curable resin resist is hardened almost completely because the thickness thereof is large. It is important that the uncured portion is sufficiently cured by the subsequent post-baking to be insolubilized in the liquid crystal.

Thereafter, an alignment film material such as polyimide is applied, baked, and rubbed to form an alignment film (also referred to as an alignment control layer) ORI1, thereby obtaining an active matrix substrate.

Next, a photosensitive black resin resist is applied on a glass substrate having a thickness of 0.7 mm or 1.1 mm,
Exposure through a photomask with a predetermined opening pattern,
After the development, baking is performed to form a black matrix BM having an opening in the pixel portion. This black matrix BM
Is coated with a photosensitive first color, for example, a red resin resist, exposed through a photomask having an opening pattern of a red filter, developed, and baked to form a red filter FI.
L (R) is formed. Hereinafter, similarly, a green filter FIL (G) and a blue filter FIL (B) are respectively formed using a second color, for example, a green resin resist, and a third color, for example, a blue resin resist.

An overcoat film OC is applied on the color filter film thus formed. The overcoat film OC serves to chemically separate the liquid crystal LC from the color filter or the black matrix and to flatten the surface of the color filter film.

An ultraviolet curable resin resist having a cured specific resistance of less than 10 ⁸ Ω · cm is applied on the entire surface of the overcoat film OC, and the resist is applied through a photomask having a desired opening at a position where a spacer is to be formed. Exposure, development and post-baking to form projections SP1. This projection SP1
The lower part and the top part have substantially the same area. The protrusion S
Similarly, it is important that P1 is sufficiently cured by post-baking to be insolubilized in the liquid crystal. Thereafter, an alignment film material is applied, baked and subjected to a rubbing treatment to form an alignment film O.
RI2 is formed, and a color filter substrate is obtained.

The active matrix substrate and the color filter substrate manufactured as described above are bonded to each other so that the top surfaces of the projections SP2 on the active matrix substrate side and the projections SP1 on the color filter substrate side are brought into contact with each other, whereby A spacer SP bridging the gap between the color filter substrates is formed. The subsequent steps of bonding the two substrates and enclosing the liquid crystal are the same as in the known method of manufacturing a liquid crystal display device.

The spacer SP of the first embodiment manufactured by this method is formed just below the black matrix BM and directly above the drain electrode SD2 in a partition shape along both sides of the pixel region. By directing the extending direction of the spacer SP toward the liquid crystal injection port, the liquid crystal filling speed can be made normal.

The spacer SP of the second embodiment can be obtained by changing the opening pattern of the photomask for exposing the ultraviolet-curable resin resist applied on the overcoat film OC in the above-described manufacturing method.

In the spacer SP of the third or fourth embodiment, the thickness of the coating film of the black matrix matrix material is increased in the process of forming the black matrix BM, or the process of forming the black matrix is performed twice. Is obtained. Further, in the first and second embodiments, the black matrix BM is formed before the formation of the color filter. However, a method in which the color filter is formed first, and then the black matrix is formed can be adopted.

Next, the embodiment of the present invention will be described more specifically with reference to the first embodiment. The optical density (OD value) of the black matrix BM of the counter substrate (color filter substrate) of the liquid crystal panel prepared by the above method is 1.8, the thickness of the projection SP1 on the counter substrate side is 1 μm, and the width is the video signal line DL. 6 μm, which is equal to the electrode width of the drain electrode SD2, and the protrusion S on the electrode substrate (active matrix substrate) side.
The film thickness of P2 was 3 μm, and the width was 6 μm, similar to that of the projection SP1. Therefore, the cell gap is 4 μm.

Using this liquid crystal panel, an active matrix type liquid crystal display device in which the voltage applied to the counter electrode was converted into an alternating current was constructed. No smear, which is the resulting crosstalk, was observed.

Hereinafter, a comparative example for clarifying the effect of the present invention will be described.

Comparative Example 1 Instead of the spacer according to the present invention, the average particle size was 4.25 μm.
m spherical spacers were dispersed to form a liquid crystal panel having the same cell gap of 4 μm as in the first embodiment. When a liquid crystal display device using this liquid crystal panel was driven under the same driving conditions as above, smear, which is crosstalk generated along the liquid crystal signal electrode, was generated, and the spherical spacers existing in the pixel portion during black display were used. Light leakage occurred, and image quality was deteriorated.

Comparative Example 2 A liquid crystal panel was constructed in the same manner as in the first embodiment. However, the specific resistance of the projection SP1 on the counter substrate side is 10 ⁴ Ω · cm.
The thickness was 4 μm, the width was 6 μm, which is the same as the electrode width, and no spacer SP2 was provided on the electrode substrate side.

When the liquid crystal display device using this liquid crystal panel was driven under the same driving conditions as above, a wide viewing angle without gradation inversion at 60 degrees in the vertical and horizontal directions, and a smear which is crosstalk generated along the liquid crystal signal electrode. Was not observed, but the drive voltage increased and the response speed also slowed.

FIG. 9 is an exploded perspective view for explaining an example of the overall configuration of the liquid crystal display device according to the present invention. This liquid crystal display device is a backlight type liquid crystal display device in which an illumination light source is installed on the back of a liquid crystal panel.

This liquid crystal display device describes a specific structure of a liquid crystal display device (module: MDL) in which a liquid crystal panel, a circuit board, a backlight and other components are integrated.

In FIG. 9, SHD is an upper frame (also referred to as a shield case or a metal frame) made of a metal plate, WD is a display window, INS1 to 3 are insulating sheets, PC
B1 to B3 are circuit boards (PCB1 is a drain side circuit board:
A video signal line driving circuit board, PCB2 is a gate side circuit board, PCB3 is an interface circuit board), JN1
Reference numeral 3 denotes a joiner for electrically connecting the circuit boards PCB1 to PCB3, TCP1 and TCP2 denote a tape carrier package, PNL denotes a liquid crystal panel having any of the structures of the above embodiments, POL denotes an upper polarizing plate, GC denotes a rubber cushion, IL
S is a light shielding spacer, PRS is a prism sheet, SPS is a diffusion sheet, GLB is a light guide plate, RFS is a reflection sheet, M
CA is a lower frame (lower case: mold frame) formed by integral molding, MO is an MCA opening, BA
T is a double-sided adhesive tape, and a liquid crystal display module MDL is assembled by stacking diffusion plate members in the arrangement shown in the figure. A light source assembly including a fluorescent tube LP and a reflection sheet LS is installed along one side of the light guide plate GLB, and the fluorescent tube LP
Power is supplied from a backlight power supply (not shown) via a lamp cable LPC pulled out from a rubber cushion GC portion provided at the end of the backlight. The light guide plate GLB and the light source assembly constitute a backlight BL. The light source assembly can be installed on two or four sides of the light guide plate GLB.

This liquid crystal display device (liquid crystal display module M)
DL) has a housing composed of two kinds of storage / holding members of a lower frame MCA and an upper frame SHD, and an insulating sheet IN
S1 to S3, circuit boards PCB1 to PCB3, and liquid crystal panel PNL are stored and fixed, and lower frame MCA storing a backlight composed of light guide plate GLB and the like is combined with upper frame SHD.

An electronic component such as an integrated circuit chip for driving each pixel of the liquid crystal panel PNL is mounted on the video signal line driving circuit board PCB1, and an image signal from an external host computer is mounted on the interface circuit board PCB3. An integrated circuit chip that accepts and receives control signals such as timing signals, and a timing converter (TCON) that processes timing to generate a clock signal, a low-voltage differential signal chip, and other electronic components such as capacitors and resistors Is done.

The clock signal generated by the timing converter is supplied to an integrated circuit chip mounted on the video signal line driving circuit board PCB1.

The interface circuit board PCB3 and the video signal line driving circuit board PCB1 are multilayer wiring boards, and the clock signal line CLL is the interface circuit board PCB3 and the video signal line driving circuit board PC
It is formed as an inner wiring of B1.

The liquid crystal panel PNL has a drain-side circuit board PCB1, a gate-side circuit board PCB2, and an interface circuit board PCB3 for driving TFTs.
Are connected by tape carrier packages TCP1 and TCP2, and the circuit boards are connected by joiners JN1, JN2, JN3.

With this liquid crystal display device, a liquid crystal display device having a wide viewing angle and a wide quality without crosstalk can be obtained.

[0089]

As described above, according to the present invention,
A projection is formed on the color filter substrate side of the liquid crystal panel constituting the in-plane switching type liquid crystal display device and on the active matrix substrate. By setting the specific resistance of the projection on the filter substrate side to less than 10 ⁸ Ω · cm, it is possible to obtain a liquid crystal display device of a horizontal electric field type with a wide viewing angle and no crosstalk. In addition, by setting the specific resistance of the protrusion on the active matrix substrate side to 10 ⁸ Ω · cm or more, a liquid crystal display device with less crosstalk can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing a vicinity of one pixel of a liquid crystal panel for explaining a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a cross-sectional view taken along line 1-1 'of FIG.

FIG. 3 is a diagram illustrating a result of an experiment on a relationship between a specific resistance of a black matrix and a driving voltage in a first embodiment of the present invention, and an explanatory diagram of a configuration of a liquid crystal cell used in the experiment.

FIG. 4 is a plan view showing a vicinity of one pixel of a liquid crystal panel for explaining a second embodiment of the liquid crystal display device according to the present invention.

FIG. 5 is a plan view showing a vicinity of one pixel of a liquid crystal panel for explaining a third embodiment of the liquid crystal display device according to the present invention.

6 is a sectional view taken along line 1-1 'of FIG.

FIG. 7 is a plan view of the vicinity of one pixel of a liquid crystal panel for explaining a fourth embodiment of the liquid crystal display device according to the present invention.

FIG. 8 shows the first embodiment of the liquid crystal display device according to the present invention.
FIG. 3 is a plan view illustrating a configuration near one pixel of the liquid crystal panel described in the example.

FIG. 9 is an exploded perspective view illustrating an example of the overall configuration of a liquid crystal display device according to the present invention.

10A and 10B are a cross-sectional view of the vicinity of an electrode of one pixel of a liquid crystal panel included in a liquid crystal display device of a horizontal electric field type and a cross-sectional view of a peripheral portion of a substrate.

FIG. 11 is a schematic explanatory diagram of a peripheral circuit of a liquid crystal display device of an in-plane switching mode.

FIG. 12 is a schematic cross-sectional view illustrating an example of the arrangement of electrodes forming one pixel of a liquid crystal panel forming a conventional liquid crystal display device of an in-plane switching mode.

[Explanation of symbols]

 AS Non-condensed silicon (a-silicon) TFT Thin film transistor Cstg Storage capacitance CL Counter voltage signal line CT, CT1, CT2 Counter electrode GL Scan signal line GT Gate electrode PX Pixel electrode SD1 Source electrode SD2 Drain electrode SP Spacer SP1 Color filter substrate side Projection SP2 Projection on the active matrix substrate side.

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[Procedure amendment]

[Submission date] November 19, 1999 (1999.11.
19)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroaki Asma 3300 Hayano, Mobara-shi, Chiba F-term (reference) 2H089 LA09 MA06X NA14 PA04 QA16 5C094 AA03 AA09 AA12 AA48 AA55 BA03 BA43 CA19 CA24 DA12 DA13 EA10 EB02 EC03 EC04 EC10 ED03 ED14 ED15 FA01 FA02 FB01 FB02 FB12 FB18 GA10 GB01 JA05

Claims (4)

[Claims] An at least one of a pair of transparent substrates has at least two or more color filters of different colors for color display and a black matrix interposed between the color filters. An electrode group for pixel selection is formed on the other side of the substrate, and a layer of a liquid crystal composition having dielectric anisotropy sandwiched between the pair of substrates,
A liquid crystal panel comprising a polarizing plate laminated on at least one outer surface of the pair of substrates, and a liquid crystal display device comprising: a driving unit for applying a driving voltage for display to the electrode group; A liquid crystal display device, comprising a spacer bridging a gap between opposing inner surfaces and having a specific resistance on the one substrate side smaller than a specific resistance on the other substrate side. 2. The liquid crystal display device according to claim 1, wherein the spacer is formed by joining top surfaces of protrusions formed on each of the pair of substrates. 3. The specific resistance of the spacer on the one substrate side is less than 10 ⁸ Ω · cm, and the specific resistance on the other substrate side is 1 Ω · cm.
Characterized in that it is a 0 ⁸ Ω · cm according to claim 1 or 2
3. The liquid crystal display device according to 1. 4. The projection on the one substrate side of the spacer is formed of an organic polymer material containing metal or carbon particles, and the projection on the other substrate side is formed of an organic polymer insulating material. The liquid crystal display device according to claim 2, wherein: