JP3486859B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large screen active matrix type liquid crystal display device having a wide viewing angle and high image quality.

[0002]

2. Description of the Related Art A method of applying an electric field to a liquid crystal composition layer using a comb-teeth-shaped electrode pair formed on one substrate of a conventional active matrix type liquid crystal display device is disclosed in, for example, Japanese Patent Laid-Open No. 7-36058. It is proposed by Japanese Patent Laid-Open No. 7-159786. Hereinafter, a display system in which the main electric field direction applied to the liquid crystal composition layer is a direction substantially parallel to the substrate interface is referred to as a lateral electric field system. 1 and 2 show an example of a conventional lateral electric field method. The common electrode and the scanning signal wiring are formed in the same layer. Further, the video signal wiring and the liquid crystal drive electrode are also formed in the same layer. Although the common electrode and the liquid crystal drive electrode are formed separately in different layers, they are linearly arranged in parallel comb teeth. Similarly, the scanning signal lines and the video signal lines are also formed in a linear parallel arrangement. The common electrode and the video signal wiring are arranged so as not to overlap each other. The additional capacitance is formed by overlapping the common electrode and the liquid crystal driving electrode with each other with an insulating film interposed therebetween. The surfaces of the common electrode and the liquid crystal driving electrode, which occupy half of the pixel area, are covered with the metal material used as it is, or with a self-oxidizing film or a self-nitriding film for preventing a short circuit.

[0003]

When the horizontal electric field type liquid crystal display device is manufactured by the above-mentioned conventional technique, the probability of short circuit is high because the scanning signal wiring and the common electrode are formed in the same layer. Similarly, since the video signal wiring and the liquid crystal drive electrode are formed in the same layer, there is a high probability of short circuit. In the former case, a horizontal line defect occurs, and in the latter case, a point defect occurs, and the image quality is significantly deteriorated. Therefore, the conventional structure has a problem of low yield and high production cost.

In the horizontal electric field system, the capacitance of the liquid crystal drive electrode becomes very small unless an additional capacitance is formed.
The non-uniformity of the leak current of T on the entire screen is likely to be uneven and visible. Therefore, in the conventional technique, the common electrode and the liquid crystal driving electrode are separately formed in different layers via an insulating film,
Although they are formed by overlapping each other, when trying to form a large additional capacitance, there is no other way but to enlarge the area of the overlapping portion by shrinking the effective screen, which causes a poor light transmittance.

In the conventional horizontal electric field system in which the common electrode and the liquid crystal driving electrode are linearly arranged in a parallel comb shape as shown in FIG. 2, the pretilt angle between the alignment film and the liquid crystal is as shown in FIG. Is known to greatly affect the viewing angle. Therefore, the liquid crystal having the pretilt of 3 ° to 8 ° and the alignment film, which are used in the TFT using the conventional TN liquid crystal, cannot be used, and when the TN method and the horizontal electric field method are produced in one production line, Since the alignment film and the liquid crystal must be exchanged, there was a problem that the production efficiency was drastically reduced.

In the horizontal electric field system, the aperture ratio is low, and even if it is designed well, it is about 50% at most. Half of the effective screen is occupied by the common electrode and the liquid crystal drive electrode.In the conventional technology, since the antireflection film is not formed on the surface of these electrodes, the liquid crystal passes through the color filter from the outside. The light that has entered the layer is reflected by the common electrode and the liquid crystal driving electrode, passes through the color filter again, and goes out. For this reason, the black level is raised to the gray side, so that there is a problem that the black level of the entire screen is worse than that of the conventional TN liquid crystal system.

The present invention solves the above problems, and an object of the present invention is to provide a large-screen high-definition active matrix type liquid crystal display device having a high contrast, a high manufacturing yield, a large aperture ratio, and a high contrast. To provide.

[0008]

[Means for Solving the Problems] The present invention adopts the following means in order to solve the above problems.

At least a part of a scanning signal line, a video signal line, a thin film transistor formed on each intersection of the scanning signal line and the video signal line on the substrate, a liquid crystal driving electrode connected to the thin film transistor, A liquid crystal display device comprising an active matrix substrate having a common electrode formed facing the liquid crystal driving electrode and a liquid crystal layer sandwiched between the counter plates, [Means 1] the scanning signal wiring and the The video signal wiring, the common electrode, and the liquid crystal driving electrode are formed and separated in different layers via an insulating film.

[Means 2] In the means 1, the video signal wiring and at least a part of the common electrode, or the scanning signal wiring and at least a part of the common electrode are overlapped with each other via an insulating film.

[Means 3] In the means 1, at least a part of the liquid crystal drive electrode, the scanning signal line, and the common electrode are overlapped with each other through an insulating film, and the overlapping portion forms an additional capacitance.

[Means 4] In the means 1, when the positive dielectric constant anisotropic liquid crystal (P-type LC) is used, the video signal wiring and the pixel electrode (the liquid crystal driving electrode and the common electrode facing the liquid crystal driving electrode) Is a ± 1 degree to the liquid crystal alignment direction.
The structure is arranged so that it is bent within a range of ± 45 degrees.

[Means 5] In the means 1, when the positive dielectric constant anisotropic liquid crystal (P-type LC) is used, the scanning signal wiring and the pixel electrode are ± 1 ° to ±± with respect to the liquid crystal alignment direction. Four
The structure is arranged to be bent in the range of 5 degrees.

[Means 6] In the means 1, when the negative dielectric constant anisotropic liquid crystal (N-type LC) is used, the video signal wiring and the pixel electrode except 90 degrees with respect to the liquid crystal alignment direction. The structure is arranged to be bent in the range of degrees to 135 degrees.

[Means 7] When the negative dielectric constant anisotropic liquid crystal (N-type LC) is used in the means 1, the scanning signal wiring and the pixel electrode except 90 degrees with respect to the liquid crystal alignment direction. The structure is arranged to be bent in the range of degrees to 135 degrees.

[Means 8] A light antireflection film layer is formed on the surface of both the liquid crystal driving electrode and the common electrode, or at least one of the electrodes.

[0017]

Since the scanning signal wiring, the video signal wiring, the common electrode, and the liquid crystal driving electrode are present in different layers with the insulating films interposed therebetween as in the above means 1, the scanning signal wiring and the common electrode are The probability of short circuit is reduced, and horizontal line defects can be reduced. The probability of occurrence of a short circuit between the video signal wiring and the liquid crystal drive electrode is also reduced, and point defects are reduced.

By the means 2 and 3, a part of the common electrode and the video signal wiring and the scanning signal wiring can be overlapped with each other through the insulating film, so that the pixel aperture ratio can be increased. In addition, since at least a part of the liquid crystal drive electrode, the scanning signal line, and the common electrode are overlapped with each other through the insulating film, the added amount can be increased, so that the TF can be increased.
It is possible to prevent the deterioration of the image quality due to the decrease of the off resistance of T. Further, since this large addition amount has an effect of reducing the fluctuation of the liquid crystal drive voltage due to the scanning signal line, it is possible to prevent the occurrence of an afterimage.

When the horizontal electric field is applied in the pixel electrode (the liquid crystal drive electrode and the common electrode) by the means 4 to 7 as shown in FIGS. 17 and 18, the liquid crystal molecules are generated in the pixel electrode. There are two types of rotational movements, left rotation and right rotation. As shown in FIG. 23, the unidirectional rotary motion alone
When the pretilt angle is large, as shown in FIG. 24, due to the characteristics of the viewing angle, a twist occurs. When two types of rotational movements of the liquid crystal molecules, that is, left rotation and right rotation, occur inside one pixel electrode, even if the pretilt angle is large, one of the characteristics of the viewing angle does not occur. Therefore, in the liquid crystal display device using the structure of the present invention, the degree of freedom in selecting the alignment film and the liquid crystal is increased without being restricted by the pretilt angle. Afterimages and response speed can be easily improved, and conventional alignment films and liquid crystals can be used, so that production efficiency can be improved. Since the effective utilization rate of the polarizing plate also increases, the cost can be downed.

By the means 8 described above, the light that has passed through the color filter from the outside and has entered the liquid crystal layer is reflected by the antireflection film formed on the common electrode and the liquid crystal driving electrode as shown in FIG. Since it disappears, the black level is improved and the contrast is increased. A high-quality image that is easy to see can be obtained.

With the means 1, 2, 3 described above, light leakage of the backlight light from other than the effective pixels is reduced, so that the BM (black mask) area of the color filter can be reduced. 37, 38, 39, 4
0, 41, and 42 completely cover the part of the TFT with one part of the common electrode or one part of the liquid crystal driving electrode, so that the semiconductor active layer of the TFT is not directly exposed to external light. This drastically reduces the photo leak current when the TFT is off. The BM (black mask) of the color filter that was absolutely necessary in the past is no longer necessary,
The manufacturing process of the color filter can be shortened and the yield can be increased, so that the cost can be reduced.

[0022]

EXAMPLE 1 FIG. 3, FIG. 4, FIG. 5, FIG. 31, FIG. 31, FIG. 36, FIG. 37, FIG. 38 are sectional and plane views of a unit pixel of an example of the first category of the present invention. It is a figure. A common electrode (common electrode) was formed on a glass substrate (10), and a base insulating film (14) made of a silicon nitride (SiN) film or a silicon oxide (SiO ₂ ) film was formed so as to cover the common electrode. Next, scan signal wiring (gate electrode) was formed. The scan signal wiring is preferably a metal such as Al that can be anodized, but may be a pure metal or alloy such as Cr, Mo, Ti, W or Ta. Using a metal with a low electric resistance, two layers,
It may be a composite metal layered in three layers. A gate insulating film is formed on the scan signal wiring and then an amorphous silicon (a-si) film is formed to be an active layer of the transistor. The video signal wiring and the drain electrode are formed so as to overlap with part of the amorphous silicon. A protective insulating film made of a SiN film is formed so as to cover all of them.
Next, through hole in SiN on the drain electrode (15)
Form ▼. A liquid crystal driving electrode is formed and is electrically connected to the drain electrode through the through hole 15. An alignment film made of polyimide was formed on the surface of the active matrix substrate in which the unit pixels made of the above were arranged in a matrix, and the surface was rubbed. Similarly, a liquid crystal composition containing rod-shaped liquid crystal molecules is enclosed between the counter substrate (11) having an alignment film on the surface of which a rubbing treatment is formed and the active matrix substrate,
Polarizing plates (12) and (13) were arranged on the outer surfaces of the two substrates.

The alignment film may be a film which does not require rubbing treatment and which has a liquid crystal alignment property by causing a photopolymerization reaction of a photopolymerization type heat-resistant polymer using linearly polarized light.
The pretilt angle is less likely to occur in the alignment by the photopolymerization type heat-resistant polymer alignment film, but the smaller the pretilt angle in the horizontal electric field type liquid crystal display mode is, the better the viewing angle characteristic is. A heat resistant polymer alignment film can also be used. As shown in FIG. 23, the liquid crystal molecules are oriented so as to form a slight angle (1 to 45 degrees) with respect to the longitudinal direction of the stripe-shaped liquid crystal drive electrode and the common electrode as shown in FIG. The alignment of liquid crystal molecules at the interface with the upper and lower substrates was parallel to each other. The dielectric anisotropy of liquid crystal molecules is positive. When liquid crystal molecules with negative dielectric anisotropy are used, the axis of the liquid crystal alignment direction and the pixel electrode,
It is sufficient to set the intersection angle of 45 degrees to 89 degrees.

Further, in this embodiment, as shown in FIG. 3, the common electrode and the liquid crystal driving electrode are insulated and separated by the insulating film (14), so that they can be overlapped as shown in FIG. Yes, this overlapping portion can act as an additional capacitance. Further, as shown in FIG. 5, the liquid crystal driving electrode can be superimposed not only on the common electrode but also on the scanning signal wiring. Thereby, the additional capacitance can be increased without lowering the aperture ratio. Furthermore, FIG.
As shown in FIG. 7 and FIG. 38, the liquid crystal driving electrode can be formed so as to cover the entire surface of the amorphous active layer of the TFT.
By overlapping a part of the common electrode with the scanning signal wiring or the video signal wiring as shown in FIGS. 31, 35 and 36, it is possible to drastically reduce the leakage of light from other than the effective pixels.

[Embodiment 2] FIGS. 6, 7, 8, 9, and 10 are a sectional view and a plan view of a unit pixel according to a second embodiment of the present invention. A scanning signal wiring (gate electrode) is formed on the glass substrate (10), and anodization processing is performed.
The anodizable metal is Al, Ta, Nb or the like. It may be an alloy of these metals or a gate electrode having a laminated structure. Next, a common electrode (common electrode) is formed, and a gate insulating film that covers the common electrode is formed. After this, Example 1
Is the same as. In the present invention, scanning signal wiring (gate electrode)
The anodic oxide film has a function of completely insulating and separating the scanning signal wiring and the common electrode. As a result, the sheet of the scanning signal wiring and the common electrode can be completely prevented. It is possible to overlap a part of the common electrode and the video signal wiring as in the first embodiment. Furthermore, by using a part of the liquid crystal driving electrode, TF
It is also possible to completely cover the active layer of T.

[Embodiment 3] FIGS. 11, 12 and 13 show
FIG. 6 is a cross-sectional view and a plan view of a unit pixel according to an example of the third class of the present invention. On the glass substrate (10), the scanning signal wiring and the common electrode central line (18) are simultaneously formed in the same layer. Next, the common electrode center line (18) and the pixel electrode (20) are processed so that they can be electrically coupled at the contact through hole portion (19), and then the scanning signal line and the common electrode center line (18) are anodized. Oxidize. Anodizable metals are
Al, Ta, Nb and the like. It may be an alloy of these metals or a gate electrode having a laminated structure. Next, the pixel electrodes 20 are formed and a gate insulating film that covers them is formed. The subsequent steps are the same as in the first embodiment. In the present invention, the anodic oxide film of the scanning signal wiring (gate electrode) has a function of completely insulating and separating the scanning signal wiring from the pixel electrode (20) which is a part of the common electrode. The distance between the scanning signal wiring and the common electrode center line (18) is generally very large, and even if they are formed in the same layer, there is almost no short circuit. It is also possible to overlap a part of the common electrode pixel electrode 20 with the video signal wiring as in the first embodiment. Furthermore, it is possible to completely cover the active layer of the TFT by using a part of the liquid crystal driving electrode.

[Embodiment 4] FIGS. 14, 15, 16, 32, 33, 34, 39, 40, 41 and 4.
2, FIG. 43, and FIG. 44 are a sectional view and a plan view of a unit pixel according to a fourth embodiment of the present invention. The scanning signal wiring (gate electrode) is formed on the glass substrate (10), the gate insulating film is formed so as to cover the wiring, and then the amorphous silicon (a-si) film is formed. Layer. Next, the video signal wiring and the drain electrode are formed. SiN film or SiO to cover all of these
_A protective insulating film composed of _two films is formed. Next, a through hole is formed on the drain electrode. A liquid crystal driving electrode is formed and is electrically connected to the drain electrode through the through hole. Next, an upper insulating film is formed and then a common electrode is formed thereon. An alignment film was formed on the surface of an active matrix substrate in which the unit pixels made of the above were arranged in a matrix, and the surface was rubbed. In this embodiment, as shown in FIG. 14, the common electrode and the liquid crystal drive electrode are insulated and separated via the insulating film (21), so that they can be overlapped as shown in FIG. Can act as an additional capacitance. Further, as shown in FIG. 16, the liquid crystal drive electrode can be superimposed not only on the common electrode but also on the scanning signal wiring. Thereby, the additional capacitance can be increased without lowering the aperture ratio. Next, FIG. 39, FIG.
As shown in FIGS. 41 and 42, the liquid crystal driving electrode and the common electrode may be formed so as to cover the entire surface of the amorphous active layer of the TFT. As shown in FIGS. 32, 33, and 34, the leakage of light from other than the effective pixels can be drastically reduced by overlapping a part of the common electrode with the scanning signal wiring and the video signal wiring. As a result, the black mask (B
A color filter that does not require M) can be used.

Further, in this embodiment, as shown in FIGS. 43 and 44, an open window can be formed by removing the upper insulating film formed on the liquid crystal drive electrode in the effective pixel. Thereby, the alignment film can be directly formed on the surfaces of the liquid crystal drive electrode and the common electrode. The liquid crystal is basically driven by an alternating current, and when a bias voltage of a direct current component is applied, the alignment film is polarized, or charge is trapped at the interface between the alignment film and the insulating film, so that an afterimage phenomenon occurs.
When both electrodes are in direct contact with the alignment film as in this embodiment, charge traps are small and afterimages are less likely to occur. In the first, second, and third embodiments, it is possible to form the open window formed in FIGS. 43 and 44.

[Embodiment 5] FIG. 17, FIG. 19, FIG. 20, FIG. 21, FIG. 25, FIG. 26, FIG. 27, FIG. 28, FIG. 29, FIG.
0 is a plan view of the fifth embodiment of the operating principle and the embodiment.
The dielectric anisotropy of liquid crystal molecules is positive. Common electrode inside the pixel and liquid crystal drive electrode, alignment axis of liquid crystal molecules (optical axis)
Bends within a range of ± 1 ° to ± 45 °. With such a structure, as shown in FIG. 17, when a voltage is applied to the common electrode and the liquid crystal driving electrode and an electric field is generated between the electrodes, the liquid crystal molecules rotate left and right with the bending portion as a boundary. There are two types of rotational movement. 2 inside the unit pixel
The fact that street rotation is possible has a great effect on the improvement of the viewing angle characteristics. 19, 20, and 21 are plan views of a unit pixel. According to the bending of the pixel electrode,
The feature is that the video signal wiring and the scanning signal wiring are bent. FIG. 25, FIG. 26, and FIG. 28 show arrangement positions of common electrodes, liquid crystal drive electrodes, scanning signal wirings, and video signal wirings when pixels are arranged in a delta arrangement in order to improve color mixing of color filters. It is a top view. This delta arrangement is mainly used for AV. 29 and 30 are plan views showing the arrangement relationship between the common electrodes, the liquid crystal drive electrodes, the scanning signal wirings, and the video signal wirings when the pixels are arranged in a stripe arrangement.
This stripe array is mainly used for OA.

[Sixth Embodiment] FIGS. 18, 19, 20, 21, 25, 26, 27, 28, 29 and 3
0 is a plan view of the operation principle of the sixth class and the embodiment. The dielectric anisotropy of liquid crystal molecules is negative. The common electrode and the liquid crystal drive electrode inside the pixel are the alignment axis (optical axis) of the liquid crystal molecules.
With respect to 90 degrees, it is bent within a range of 45 degrees to 135 degrees. As shown in FIG. 18, when a voltage is applied to the common electrode and the liquid crystal driving electrode to generate an electric field between the electrodes, the liquid crystal molecules rotate in two ways, a left rotation and a right rotation, with the bending portion as a boundary. do. This is exactly the same as the fifth embodiment in that the fact that two types of rotational movements are possible inside the unit pixel is effective in improving the viewing angle characteristics. The plan view structure of the unit pixel and the plan view structure regarding the pixel array are described in the fifth embodiment.
Is exactly the same. The feature is that the video signal wiring and the scanning signal distribution are bent in accordance with the bending of the pixel electrode. In both Example 5 and Example 6, the rubbing treatment is performed so that the alignment of liquid crystal molecules at the interface with the upper and lower substrates is parallel to each other. The polarizing axes (optical axes) of the polarizing plates are vertically arranged vertically, and in a normally black mode, light does not pass from the pixels when there is no electric field.

[Embodiment 7] FIG. 22 is a sectional view of an embodiment of the seventh category. An antireflection layer is formed on the surface of the pixel electrode (common electrode and liquid crystal drive electrode) to prevent the light from being reflected by the pixel electrode and going out again when light from the outside enters the liquid crystal layer. Has been done. As a typical example, in the case of Cr metal, Cr \ CrN \ CrO or C
There is a double-layer structure of a nitride film such as r \ CrO and an oxide film, or a single-layer structure of only an oxide film. Similarly for Mo metal, Mo
The structure of \ MoN \ MoO or Mo \ MoO is used.
In addition, a considerable antireflection effect can be obtained by coating the surface of the pixel electrode with an a-si layer or carbon. Cr \ CrSix or Mo \ MoS
ix, Ti \ TiSix, W \ WSixTa \ TaSi
Metal silicide such as x, Nb \ NbSix can be used because it has a light reflection preventing effect.

Further, the same effect can be obtained by forming an antireflection film layer on the insulating film on the pixel electrode as shown in FIG. In this case, an antireflection film of an insulating film is suitable.
An a-si layer, a blue pigment resist used in a color filter, a black pigment resist, or the like can be used.

In the case of a color filter having no black mask on the counter substrate (11), an antireflection film layer is formed on the surfaces of the scanning signal electrodes and the video signal electrodes as shown in FIG. A horizontal electric field type liquid crystal display device having a very good contrast can be manufactured.

[0034]

As described above, according to the present invention, since the scanning signal wiring, the video signal wiring, the common electrode, and the liquid crystal driving electrode are formed in different layers by insulating films, respectively, a short circuit does not occur. A liquid crystal panel with high aperture ratio and high contrast and little afterimage can be produced. Further, by bending the pixel electrode with respect to the liquid crystal alignment direction, the rotation directions of the two liquid crystal molecules can be created in the unit pixel, and the viewing angle can be expanded. The cost can be reduced because the orientation material that has been used conventionally can be used.

[Brief description of drawings]

FIG. 1 is a sectional view of a conventional horizontal electric field type unit pixel.

FIG. 2 is a plan view of a conventional horizontal electric field type unit pixel.

FIG. 3 is a sectional view of a horizontal electric field type unit pixel of the present invention (Example 1).

FIG. 4 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 1).

FIG. 5 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 1).

FIG. 6 is a cross-sectional view of a horizontal electric field type unit pixel of the present invention (Example 2).

FIG. 7 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 2).

FIG. 8 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 2).

FIG. 9 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 2).

FIG. 10 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 2).

FIG. 11 is a sectional view of a horizontal electric field type unit pixel of the present invention (Example 3).

FIG. 12 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 3).

FIG. 13 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 3).

FIG. 14 is a sectional view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 15 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 16 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 17 is an alignment direction diagram of a positive dielectric constant anisotropic liquid crystal in a lateral electric field type bent pixel electrode of the present invention (Example 5).

FIG. 18 is a view showing the alignment direction of the negative dielectric constant anisotropic liquid crystal in the horizontal electric field type bent pixel electrode of the present invention (Example 6).

FIG. 19 is a plan view of a horizontal electric field type unit pixel of the present invention (Examples 5 and 6).

FIG. 20 is a plan view of a horizontal electric field type unit pixel of the present invention (Examples 5 and 6).

FIG. 21 is a plan view of a horizontal electric field type unit pixel of the present invention (Examples 5 and 6).

FIG. 22 is a sectional view of a pixel electrode with an in-plane switching type antireflection film of the present invention (Example 7).

FIG. 23 is an alignment direction diagram of a liquid crystal having a positive dielectric constant anisotropy in a horizontal electric field type pixel electrode (Example 1, Example 2, Example 3,
Example 4)

FIG. 24: Pretilt angle and viewing angle characteristics of liquid crystal molecules of a horizontal electric field type liquid crystal display device

FIG. 25 is a plan view of a horizontal electric field type pixel array according to the present invention (Examples 5 and 6).

FIG. 26 is a plan view of a horizontal electric field type pixel array according to the present invention (Examples 5 and 6).

FIG. 27 is a plan view of a horizontal electric field type pixel array according to the present invention (Examples 5 and 6).

FIG. 28 is a plan view of a horizontal electric field type pixel array according to the present invention (Examples 5 and 6).

FIG. 29 is a plan view of a horizontal electric field type pixel array according to the present invention (Examples 5 and 6).

FIG. 30 is a plan view of a horizontal electric field type pixel array according to the present invention (Examples 5 and 6).

FIG. 31 is a sectional view of the overlapping portion of the common electrode and the video signal wiring according to the present invention (Example 1).

FIG. 32 is a sectional view of the overlapping portion of the common electrode and the video signal wiring according to the present invention (Example 4).

FIG. 33 is a cross-sectional view of the overlapping portion of the common electrode, the liquid crystal drive electrode, and the scanning signal wiring according to the present invention (Example 4)

FIG. 34 is a cross-sectional view of the overlapping portion of the common electrode, the liquid crystal drive electrode, and the scanning signal wiring according to the present invention (Example 4)

FIG. 35 is a cross-sectional view of the overlapping portion of the common electrode, the liquid crystal drive electrode, and the scanning signal wiring according to the present invention (Example 1).

FIG. 36 is a cross-sectional view of the overlapping portion of the common electrode, the liquid crystal drive electrode, and the scanning signal line according to the present invention (Example 1).

FIG. 37 is a cross-sectional view of the active layer of the transistor portion including the scanning signal line and the liquid crystal drive electrode according to the present invention, sandwiched between the embodiments (Example 1).

FIG. 38 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 1).

FIG. 39 is a cross-sectional view of an active layer of a transistor portion including a scanning signal line and a liquid crystal driving electrode according to the present invention, sandwiched between the layers (Example 4).

FIG. 40 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 41 is a cross-sectional view of the active layer of the transistor portion including the scanning signal line and the common electrode according to the present invention, sandwiched between the layers (Example 4).

FIG. 42 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 43 is a sectional view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 44 is a plan view of a horizontal electric field type unit pixel of the present invention (Example 4).

FIG. 45 is a cross-sectional view of a pixel electrode with a lateral electric field type antireflection film of the present invention (Example 7).

[Explanation of symbols]

1 --- scanning signal wiring 2--video signal wiring 3--common electrode 4--liquid crystal driving electrode 5--gate insulating film 6-protecting insulating film 7-TFT substrate side alignment film 8--counter substrate side alignment Film 9--Liquid crystal molecule (positive dielectric constant anisotropic liquid crystal) 10--TFT side glass substrate 11--Counter glass substrate 12--TFT side polarizing plate 13--Counter substrate side polarizing plate 14--Underground insulating film 15 --- Drain Through Hole 16 --- Retention Capacitance Forming Region 17 --- Anodic Oxide Film 18 --- Common Electrode (Center Line) Simultaneously Formed of the Same Material as the Scan Signal Wiring 19--Common Electrode Through Hole 20--Common Pixel electrode 21 that is in contact with the common electrode (center line) through the electrode through hole --- Upper insulating film 22 --- Visible light antireflection film 23 --- Liquid crystal molecule (negative dielectric constant anisotropic liquid crystal) 3-F- Made of the same material as the common electrode at the same time Shielding film A--P-type liquid crystal molecule alignment direction and pixel electrode (common electrode and liquid crystal drive electrode) intersecting angle B--N-type liquid crystal molecule alignment direction and pixel electrode (common electrode and liquid crystal drive electrode) intersecting Angle P --- Alignment direction of liquid crystal molecules and polarization axis direction of polarizing plate (optical axis) Q --- Polarization axis direction of polarizing plate (optical axis) D --- Transistor drain electrode T-formed simultaneously with video signal wiring -Semiconductor layer --- Liquid crystal drive electrode open window

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-7-36058 (JP, A) JP-A-7-43744 (JP, A) JP-A-4-309928 (JP, A) JP-A-7- 306417 (JP, A) JP-A-6-273803 (JP, A) JP-A-7-134301 (JP, A) JP-A-7-234414 (JP, A) JP-A-7-128683 (JP, A) JP-A-7-72507 (JP, A) JP-A-9-230311 (JP, A) JP-A-60-12770 (JP, A) JP-A-8-286176 (JP, A) International Publication 97/10530 ( WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1343 G02F 1/1362 G02F 1/1333 G02F 1/1335 G02F 1/133

Claims (5)

(57) [Claims] 1. A scanning signal line, a video signal line, a thin film transistor formed at each intersection of the scanning signal line and the video signal line on a substrate, and a liquid crystal drive electrode connected to the thin film transistor, and at least a part of the thin film transistor. An active matrix substrate having a common electrode formed to face the liquid crystal drive electrode, a counter substrate facing the active matrix substrate, and a horizontal substrate including the active matrix substrate and a liquid crystal layer sandwiched between the counter substrates. In the electric field type liquid crystal display device, the scanning line signal wiring, the video signal wiring, the liquid crystal drive electrode, and the common electrode are formed and separated in different layers via an insulating film, respectively, and the common electrode is active. Formed on the passivation layer of the matrix substrate, in direct contact with the alignment film, and No. common electrode is disposed so as to overlap with the video signal lines on both sides of the wiring, and the common electrode of each pixel plane switching mode liquid crystal display device characterized by being connected to each other in the upper layer of the video signal lines 2. A scanning signal line, a video signal line, a thin film transistor formed at each intersection of the scanning signal line and the video signal line on a substrate, and a liquid crystal drive electrode connected to the thin film transistor, and at least a part of the thin film transistor. A horizontal matrix composed of an active matrix substrate having a common electrode formed facing the liquid crystal driving electrode, a counter substrate facing the active matrix substrate, and a liquid crystal layer sandwiched between the active matrix substrate and the counter substrate. In the electric field type liquid crystal display device, the scanning signal line, the video signal line, the liquid crystal driving electrode, and the common electrode are formed and separated in different layers via an insulating film, respectively, and the common electrode is an active matrix. It is formed on the passivation layer of the substrate, is in direct contact with the alignment film, and has a scanning signal. A common electrode is arranged on both sides of the wiring so as to overlap with the scanning signal wiring, a common electrode is arranged on both sides of the video signal wiring so as to overlap with the video signal wiring, and the common electrode of each pixel is a video signal. A lateral electrolysis type liquid crystal display device characterized by being connected to each other in an upper layer of wiring 3. The liquid crystal driving electrode according to claim 1, wherein the liquid crystal driving electrode is sandwiched by the common electrode and the scanning signal wiring from the upper layer and the lower layer via the insulating layer, and the additional capacitance is provided between the upper layer and the lower layer of the liquid crystal driving electrode by the overlapping portion. In-plane switching mode liquid crystal display device characterized by being formed 4. The BM (black) on the counter substrate side, which completely covers the semiconductor active layer of the thin film transistor with a part of the common electrode or a part of the liquid crystal driving electrode and faces the active matrix substrate. mask)
In-plane switching liquid crystal display device characterized by the absence of 5. A lateral electric field type liquid crystal display device according to claim 1, wherein a visible light antireflection film layer is formed on the surface of either or both of the common electrode and the liquid crystal driving electrode.