JP2000066224A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the phenomenon that the influence of the disclination on electrodes appears in apertures, to improve panel transmittance and to decrease residual images and display unevenness by constituting the device in such a manner that an effective panel gap increases when the region on the side where the direction toward liquid crystals from a first substrate is in the direction approaching common electrodes and pixel electrodes is compared with another region. SOLUTION: Insulating film slits 210 parallel with the electrodes in contact with the electrodes are formed in protective insulating films or gate insulating films alongside the rubbing up stream side of the common electrodes 106 and the pixel electrodes 104. The portions where these insulating film slits 210 are formed are so formed that the effective gap panel is large in these portions and that the increase in the tilt angle by the z axis direction component of electric fields and the increase in the twist angle by the electric fields of x, y directions are larger compared with the portions where there are no insulating film slits 210. As a result, the phenomenon that the influence of the disclination on the electrodes appear in the apertures may be suppressed.

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 lateral electric field driving type (IPS: in-plane switching mode) liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device is a TN (Twisted
Nematic) mode, an electric field acts in a direction perpendicular to the substrate surface to change the director (molecular axis) orientation of the liquid crystal molecules, thereby controlling the light transmittance. A type that displays an image on a panel (hereinafter, referred to as a vertical electric field driving type) was generally used. However, in this vertical electric field driving type liquid crystal display device, when an electric field is applied, the director is oriented perpendicular to the substrate surface, and as a result, the refractive index changes depending on the viewing angle direction, so that the viewing angle dependence is strong, and the liquid crystal display device has a wide viewing angle. It is not suitable for applications requiring a viewing angle.

On the other hand, the director of liquid crystal molecules is oriented parallel to the substrate surface, and an electric field is applied in a direction parallel to the substrate surface to rotate the director in a plane parallel to the substrate surface. In recent years, a liquid crystal display device of a type that performs image display by controlling light transmittance (hereinafter, referred to as a lateral electric field driving type) has been researched and developed. In the liquid crystal display device of the lateral electric field driving type, since the change in the refractive index in the viewing angle direction is extremely small, high-quality display performance can be obtained in a wide field of view. The present invention is directed to this lateral electric field drive type liquid crystal display device.

[0004] Liquid crystal displays include passive matrix displays without active elements such as STN,
There is an active matrix display having an active element in each display pixel represented by FT and MIM. In the present invention, the presence or absence of an active element is not limited as long as it is a lateral electric field driving type. In the following, a TFT type active matrix display will be particularly described.

First, the configuration of the prior art will be described. FIG. 10 shows a plan view of a display pixel. The display pixels include a scanning line 502 connected to an external driving circuit, a signal line 103, and a common electrode 10.
6, and a thin film transistor 5 as a switching element
03 and a pixel electrode 104. FIG. 11 shows a cross-sectional view taken along aa ′ of FIG.

In FIG. 11, a TFT-side glass substrate 10 is provided.
2, a common electrode 106 is formed, on which a pixel electrode 104 and a signal line 103 are formed via a gate insulating film 130. At this time, the pixel electrodes 104 and the common electrodes 106 are alternately arranged. These electrodes are covered with a protective insulating film 110, on which a TFT-side alignment film 120 necessary for aligning the liquid crystal 107 is applied and rubbed. Thus, the TFT-side substrate 100 is formed.

The light-shielding film 20 is formed on the glass substrate 101 on the opposite side.
3 are provided in a matrix, on which a color layer 142 necessary for color display is formed. Further, a flattening film 202 necessary for flattening the counter substrate is provided thereon, and a counter-side alignment film 122 necessary for aligning the liquid crystal 107 is applied thereon and subjected to a rubbing process. The rubbing direction is opposite to the direction applied to the TFT-side substrate 100. Thus, the opposing substrate 200 is formed.

A liquid crystal 107 and a spacer 302 are sealed between the TFT side substrate 100 and the opposite side substrate 200. The gap between the two substrates is determined by the diameter of the spacer 302. Lastly, a TFT-side polarizing plate 145 is attached to the surface of the TFT-side glass substrate 102 where no electrode pattern is formed, so that the transmission axis is orthogonal to the rubbing direction. The opposite-side polarizing plate 143 is attached such that the transmission axis is orthogonal to the transmission axis direction of the TFT-side polarizing plate 145. Thus, the liquid crystal display panel 300 is completed.

FIG. 12 shows a configuration of a liquid crystal display device. The liquid crystal display panel 300 is installed on the backlight 400 and connected to the driving circuit 500.

Next, the operation will be described. In FIG. 10, ON / O of the scanning line 502 provided in the same layer as the common electrode 106 is shown.
The thin film transistor 503 is switched by the FF signal, and when the thin film transistor 503 is on, electric charge flows from the signal line 103 to the pixel electrode 104 and turns off.
After that, the electric charge is held and a certain potential is maintained. A constant DC voltage is constantly applied to the common electrode 106. Signals to the scanning line 502, the signal line 103, and the common electrode 106 are supplied from the driving circuit 500 in FIG. Due to a potential difference between the pixel electrode 104 and the common electrode 106 caused by these signals, a horizontal electric field parallel to the glass substrate is generated.

As a result, as shown in FIG. 13, the liquid crystal molecules 303 rotate by the action of the dielectric anisotropy of the liquid crystal and the component of the surrounding electric field parallel to the glass substrate (FIG. 13 shows the dielectric constant of the liquid crystal). When the anisotropy is positive, when the anisotropy is negative, the rotation is reversed.) The retardation of the liquid crystal layer changes,
3, the pixel electrode 104, the common electrode 106, the scanning line 502,
At a portion where the thin film transistor 503 is not installed, the amount of light transmitted from the backlight 400 in FIG. The change in the amount of light transmitted through the panel can be approximately expressed as in equation (1).

[0012]

(Equation 1) ：: angle between the average liquid crystal alignment direction and the initial alignment direction Δn: refractive index anisotropy of the liquid crystal d: cell gap λ: transmitted light wavelength Here, the angle Ψ is the voltage between the common electrode 106 and the pixel electrode 104. Is a function that depends on FIG. 14 shows an example of the result of measuring the relationship between the voltage between the electrodes and the amount of light transmission. here,
The maximum transmittance is called peak transmittance. The above is the configuration and operation of the related art. The main disadvantages of the prior art are as follows.

When the width of the pixel electrode is reduced in order to obtain a high aperture ratio, reverse tilt mode disclination appears at the opening beside the electrode, and the following problems occur.

The decrease in transmittance, uneven brightness, afterimage feeling The reason for the above drawbacks is considered as follows.
The common electrode 106 and the pixel electrode 10 of the horizontal electric field type liquid crystal display device
The liquid crystal alignment near No. 4 (hereinafter these two electrodes are simply referred to as electrodes) will be considered. A rubbing process is performed on the TFT-side alignment film 120 in the direction shown in FIG.
When injected between the counter substrate 200 and the counter substrate 200, the liquid crystals 107 are arranged on the TFT substrate 100 on the TFT substrate 100 at a constant angle θ ⁰ called a pretilt angle determined by a liquid crystal material and an alignment film material. To give an example, θ = 3-4 °
It is about. When a voltage is applied to the electrode, a radial electric field is formed in the vicinity of and on the electrode, so that the liquid crystal molecules generate a torque that rotates in the xy plane and a torque that tends to rise in the z-axis direction. Assuming that the angle between the direction of the director of the liquid crystal and the direction of the electric field in FIG. 16 is α and the magnitude of the generated torque is T, the relationship between T and α is approximately expressed by equation (2).

[0015]

(Equation 2) Here, Δε is the dielectric anisotropy of the liquid crystal, and E is the electric field strength of the liquid crystal. FIG. 16 shows the electric field near the electrode when a voltage is applied to the electrode and the direction of the rotational torque when the liquid crystal tries to rise in the z-axis direction. However, FIG. 16 depicts the director projected on the yz plane. In FIG. 16, due to the electric field generated from the electrode, the liquid crystal existing on the rubbing upstream side among the liquid crystals near the electrode receives a clockwise torque toward the paper surface, and the liquid crystal existing on the rubbing downstream side receives a counterclockwise torque. The magnitude of the torque received is in accordance with equation (2). The torque equilibrium point is located on the rubbing upstream side from the center of the electrode due to the influence of the pretilt angle (point A). At this point, the electric field is almost perpendicularly incident on the director of the liquid crystal, and the liquid crystal substantially maintains the initial tilt angle (pretilt angle) ((2)).
Α = 90 ° in the equation). Generally, such a discontinuous plane of the orientation vector of the liquid crystal is called disclination. In particular, in this case, since the tilt angle of the liquid crystal changes discontinuously, it is called a reverse tilt type disclination. Since the liquid crystal has anisotropy in the dielectric constant, the electric field distribution changes due to the rise of the liquid crystal near the electrode. The magnitude E of the electric field in the dielectric can be described as equation (3) when the electric field in vacuum is E ₀ .

[0016]

(Equation 3) (Here, ε ₀ is the dielectric constant in a vacuum.) In a liquid crystal with Δε> 0, the director direction has a large dielectric constant, so that the component of the electric field in the director direction is smaller than the expression (3). Then, since the equipotential surface is as shown in FIG. 17B, the position where the electric field parallel to the z-axis direction, that is, the xy component of the electric field becomes 0 near the electrode is located slightly upstream of the rubbing from the center of the electrode. I do. When the liquid crystal does not have a pretilt angle, the equipotential surface is symmetric with respect to the electrodes as shown in FIG. 17 (a). However, in the liquid crystal panel formed by the rubbing method, the pretilt angle appears, so that FIG. ). At this time, the electric field x, y
At the position where the component becomes 0, as shown in FIG.
Since 03 does not rotate in the x and y planes, the liquid crystal molecules substantially maintain the initial orientation direction, and the light transmittance is low. As described above, at the position of the reverse tilt disclination on the electrode in the in-plane switching mode liquid crystal display device, the liquid crystal molecules almost maintain the initial orientation direction. The position of the disclination is determined by the electric field distribution near the electrode and the pretilt angle. In a structure in which a large electric field component in the z-axis direction is generated near the electrode edge as typified by a narrow electrode width, it can be said that the position of the disclination is close to the opening. If the effect of the disclination appears in the opening, the transmittance of the opening naturally decreases.

The above is a simple consideration of the director distribution of the liquid crystal in the vicinity of the electrode. However, the determination of the electric field distribution and the orientation of the liquid crystal are simultaneous phenomena, and it is difficult to perform a detailed consideration by an analytical method. is there. Therefore, in the following, the director distribution was actually calculated by a numerical calculation method.

FIGS. 19 and 20 show the results of numerical calculation of the director distribution and transmittance of the liquid crystal when the electrode width is 4 μm and when the electrode width is 2 μm. How to read FIGS. 19 and 20 will be described below. The upper diagram (a) shows the director distribution of the liquid crystal and the lower diagram (b) shows the transmittance distribution of the liquid crystal cell. The area enclosed by a square in the above figure (a) is a portion where liquid crystal is sealed, and a short line segment is a projection of a director of liquid crystal molecules onto the y and z planes. The upper side of the liquid crystal layer is a TFT-side substrate, and the lower side is a counter-side substrate. The common electrode and the pixel electrode (collectively referred to as electrodes) have the same layer shape because of the calculation speed. In the lower diagram (b), the distribution of the transmittance at each position near the electrode in the element is drawn for each of several types of inter-electrode voltages. The electrodes are drawn in a rectangle. 19 and 20, the following can be seen.

When the electrode width is 2 μm, the disclination appears in the opening, and the transmittance is reduced around that portion. When the electrode width is 4 μm, the disclination is hidden on the electrode, and the influence on the transmittance at the opening is small.

In general, when disclination occurs in an opening, not only does the transmittance decrease, but when disclination occurs in an opening, a transient state of disclination formation is visible to the user. To the eyes as afterimages. Further, when there is a variation in the position where disclination occurs in the plane, non-uniformity of transmittance in the plane, that is, so-called display unevenness occurs.

[0021]

SUMMARY OF THE INVENTION The present invention relates to a liquid crystal display of a lateral electric field drive type, which suppresses a phenomenon in which the effect of disclination on electrodes appears in an opening, improves panel transmittance, improves afterimages, and displays images. The purpose is to reduce unevenness.

[0022]

The present invention to achieve the above object is as follows. 1. A first transparent substrate, a common electrode extending over the first transparent substrate, a scanning signal line, and a gate insulating film interposed in parallel with the common electrode and separated from each other. A pixel electrode and a signal line, an uppermost layer covered with a protective insulating film, an electrode structure and an active element provided for each of a plurality of pixels arranged in a matrix, and a rubbing method provided on the electrode structure; A first substrate including an alignment-treated first alignment film, a second transparent substrate, and a light-shielding film and an alignment-treated second alignment film on the second transparent substrate. The second alignment film is provided so as to face the first alignment film of the first substrate, and an opening region exposing at least a part of the pixel electrode for each pixel is formed in the light shielding film. A second substrate having a first substrate on the first substrate; And a layer of a liquid crystal composition having a positive dielectric anisotropy accommodated between the second alignment film and the second alignment film on the second substrate. In the device, of the regions present adjacent to the common electrode and the pixel electrode on the left and right sides, the region on the side where the direction from the first substrate of the liquid crystal director toward the liquid crystal is closer to the common electrode and the pixel electrode is the other region. A liquid crystal display device characterized in that the effective panel gap is made thicker as compared with the region (1). 2. The liquid crystal display device according to the above item 1, wherein the structure obtained by increasing the effective panel gap is that a slit extending parallel to the longitudinal direction of the electrode is provided in at least one of the gate insulating film and the protective insulating film. . 3. The liquid crystal display device according to the above item 1, wherein the structure obtained by increasing the effective panel gap is that a slit is partially provided in at least one of a gate insulating film and a protective insulating film. 4. The structure in which the effective panel gap is thickened, wherein a slit extending parallel to the longitudinal direction of the electrode is provided on at least one of the gate insulating film and the protective insulating film so as to partially overlap the electrode. 2. The liquid crystal display device according to the above item 1, wherein 5 The structure for increasing the effective panel gap is as follows:
2. The liquid crystal display device according to the above item 1, wherein a slit extending in parallel with the longitudinal direction of the electrode and a part of the electrode are partially provided on at least one of the gate insulating film and the protective insulating film. 6. The liquid crystal display device according to any one of the above items 1 to 5, wherein both the first transparent substrate and the second transparent substrate are glass substrates. 7. The method for manufacturing a liquid crystal display device according to 1 above,
A manufacturing method, wherein a slit parallel to a longitudinal direction of an electrode is at least partially formed in at least one of a gate insulating film and a protective insulating film. 8. The manufacturing method according to the above 7, wherein the slit is formed so as to partially overlap the electrode.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples. Although the drawing illustrates a TFT driven active matrix type as a representative, the present invention can be applied to other methods as long as it is a horizontal electric field driving type liquid crystal display device. Also, the following is discussed on behalf of the pre-tilt expression by the rubbing method, but the present invention can be applied to those in which the pre-tilt angle is expressed by a method such as a photo-alignment method or an oblique deposition method,
The expression means does not matter. The coordinate system is such that the x-axis is taken in the longitudinal direction of the electrode, the y-axis is taken in a direction perpendicular to the longitudinal direction, and the z-axis is taken in the cell thickness direction perpendicular to the glass substrate, on the glass substrate plane.

[0024]

Embodiment 1 The structure of Embodiment 1 will be described with reference to the drawings. Figure 1 is a plan view
FIG. 2 is a cross-sectional view of the bb ′ TFT-side substrate. The difference from the conventional technology is that the common electrode 106, the pixel electrode 10
In the protective insulating film or the gate insulating film on the side of the rubbing upstream side of No. 4, an insulating film slit 210 in contact with and parallel to the electrode.
Is formed. Other configurations are the same as those of the related art.

FIG. 3 is a schematic diagram showing the electric field near the electrodes and the orientation direction of the liquid crystal.

Since the threshold voltage is generally proportional to the reciprocal of the size of the panel gap, the effective panel gap is large in the portion where the insulating film slit 210 is formed, and the tilt angle due to the z-axis component of the electric field is increased. And an increase in the twist angle due to the electric field in the x and y directions are larger than those in a portion where the insulating film slit 210 is not provided. Due to the effect of increasing the tilt angle and the twist angle on the upstream side of the rubbing, a portion where the tilt angle and the twist angle do not change from the initial orientation azimuth, that is, a region where light does not pass, is closer to the center of the electrode as compared with the related art. Become. FIG. 4 shows a comparison diagram of the twist angle distribution with the prior art. However, if the binding force in the vicinity of the electrode on the upstream side of the rubbing is weakened by a certain value or more, the effect of disclination appears on the downstream side of the rubbing, so the slit width needs to be set appropriately.

FIG. 5 shows the result of calculating the director distribution and transmittance distribution in the structure of the present invention by liquid crystal simulation.
Shown in The way of reading the figures is the same as in FIGS. 19 and 20 described above. However, the electrodes are formed in the same layer for the sake of calculation speed. The shape of the insulating film slit 210 is a taper width of 1 μm,
The flat part is 1 μm and the depth is 0.5 μm.

Unlike the prior art, the disclination is hidden by the electrode, so that the transmittance at the opening is also improved. As described in the operation section, the shape of the insulating film slit 210 needs to be set to an appropriate size in order to keep the reverse tilt disclination on the electrode.
When the interelectrode space is 10 μm and the electrode width is 2 μm, the depth of the insulating film slit 210 is constant (= 0.5 μm), the taper width is also constant (1 μm), and the width of the slit (taper width + width of flat portion) is reduced. FIG. 6 shows the result of calculating the average transmittance of the opening by changing the average transmittance. The voltage between the electrodes is set to a voltage that gives a peak transmittance. In this case, it is understood that the optimum case is when the width of the slit is 3 μm.

Actually, a liquid crystal panel having the cross-sectional shape shown in FIG. 2A was prepared, and the transmittance was measured. As a result, it was confirmed that the peak transmittance was improved by 10% as compared with the prior art. Here, the values of the parameters are an electrode width of 2 μm, a space between the electrodes of 15 μm, a slit width of 4 μm, and a slit depth of 0.3 μm. However, the contrast is reduced by 5% because the initial alignment of the liquid crystal is disturbed by the step of the insulating film slit 210 and the rubbing strength is substantially reduced at the bottom of the insulating film slit 210. It is considered that the initial orientation direction of the liquid crystal is disturbed compared to the prior art, and the transmittance in black display increases.

Embodiment 2 FIG. 7 shows a plan view of Embodiment 2 of the present invention. The difference from the first embodiment is that the insulating film slit 210 is partially formed on the side of the electrode, and the cross-sectional shape and other configurations are the same as those of the first embodiment.

The basic operation is the same as that of the first embodiment,
The same effect as in the first embodiment is generated by the insulating film slit 210 provided partially, and the other portion is formed by utilizing the intermolecular interaction of the nematic liquid crystal (the property that the director faces the same direction). The effect is spread.

FIG. 7 is a plan view and FIG.
When the liquid crystal panel of (a) was prepared and the transmittance was measured, the peak transmittance was improved by about 3% as compared with the prior art. Here, the value of each parameter is an electrode width of 2 μm, a space between the electrodes is 15 μm, and a slit width is 4 μm in the x-axis direction and 1 in the y-axis direction.
0 μm and the depth of the slit is 0.3 μm. Although the transmittance improvement value was lower than that of Example 1, the decrease in contrast was suppressed to 0.5% or less. It is considered that since the slit area is small, the disturbance of the alignment of the liquid crystal due to the weak rubbing at the slit boundary and the slit bottom can be ignored.

Embodiment 3 The structure of Embodiment 3 will be described with reference to the drawings. Fig. 8
FIG. 9 is a sectional view taken along line dd ′.

The difference in structure from the prior art is that the common electrode 10
Sixth, the insulating film slit 210 is formed in a part of the protective insulating film or the gate insulating film on the electrode other than the side of the pixel electrode 104 on the rubbing upstream side. Other configurations are the same as those of the related art. A slit may be formed partially as in the second embodiment.

The basic operation is the same as that of the first and second embodiments. The effect of the first and second embodiments is emphasized because the edge of the electrode on the rubbing upstream side is in contact with the alignment film. As a result of the performance test of the liquid crystal panel of this example, the same peak transmittance was obtained as compared with Examples 1 and 2, and a high contrast (3% improvement compared to Examples 1 and 2) was realized. However, since the electrode width is about 2 to 4 μm, a fine process is required when forming the slit.

[0036]

According to the present invention, in a lateral electric field driving type liquid crystal display device, a portion having a lower threshold voltage than other regions is formed in a region on the rubbing upstream side of a pixel electrode or a common electrode. It is possible to suppress a phenomenon in which the effect of disclination on the electrode appears at the opening, thereby improving panel transmittance, reducing afterimages, and reducing display unevenness.

[Brief description of the drawings]

FIG. 1 is a plan view of a unit pixel according to a first embodiment.

FIG. 2 is a cross-sectional view of the structure of the first embodiment.

FIG. 3 is a schematic diagram illustrating a relationship between an electric field near an electrode and a tilt angle in Example 1.

FIG. 4 is a schematic diagram showing a distribution of a twist angle of a liquid crystal in the vicinity of an electrode in Example 1.

FIG. 5 is a result of calculating a director distribution and a transmittance distribution of Example 1.

FIG. 6 shows the result of calculating the relationship between the electrode side slit width and the peak transmittance in Example 1.

FIG. 7 is a plan view of a unit pixel according to a second embodiment.

FIG. 8 is a plan view of a unit pixel according to a third embodiment.

FIG. 9 is a cross-sectional view of a unit pixel according to a third embodiment.

FIG. 10 is a plan view of a conventional unit pixel.

FIG. 11 is a cross-sectional view of a prior art structure.

FIG. 12 is a configuration diagram of a general transmission type liquid crystal display device.

FIG. 13 is a schematic diagram illustrating an optical operation of a liquid crystal display device of a lateral electric field driving type.

FIG. 14 is a diagram showing an operation (voltage / luminance characteristic) according to the related art.

FIG. 15 is a schematic diagram showing the relationship between the rubbing direction and the formation of a pretilt angle.

FIG. 16 is a schematic view showing a rising direction of a liquid crystal in the vicinity of an electrode according to a conventional technique.

FIG. 17 is a schematic diagram of a potential distribution in the vicinity of an electrode according to a conventional technique.

FIG. 18 is a schematic diagram showing a conventional liquid crystal twisting orientation in the vicinity of an electrode.

FIG. 19 is a diagram showing a calculation result of a tilt angle and a transmittance distribution of a conventional technique (electrode width: 4 μm).

FIG. 20 is a diagram showing a calculation result of a tilt angle and a transmittance distribution of a conventional technique (electrode width: 2 μm).

[Explanation of symbols]

 100: TFT side substrate 101: Opposite side glass substrate 102: TFT side glass substrate 103: Signal line 104: Pixel electrode 106: Common electrode 107: Liquid crystal 110: Protective insulating film 120: TFT side alignment film 122: Opposite side alignment film 130 : Gate insulating film 142: Color layer 143: Opposite polarizing plate 145: TFT side polarizing plate 200: Opposing substrate 202: Flattening film 203: Light shielding film 210: Insulating film slit 300: Liquid crystal display panel 302: Spacer 303: Liquid crystal Molecule 400: backlight 500: driving circuit 502: scanning line 503: thin film transistor

Claims (8)

[Claims] A first transparent substrate, a common electrode extending on the first transparent substrate, a scanning signal line, and a gate insulating film interposed in parallel with and separated from the common electrode, respectively. An electrode structure and an active element provided for each of a plurality of pixels arranged in a matrix, having a pixel electrode and a video signal line extending in A first substrate provided with a first alignment film that has been subjected to an alignment process by a rubbing method; a second transparent substrate; and a light-shielding film and an alignment process that have been performed on the second transparent substrate. An opening region in which two alignment films are sequentially provided, the second alignment film is provided so as to face the first alignment film of the first substrate, and at least a part of the pixel electrode is exposed for each pixel. A second substrate having the light shielding film, A lateral electric field driving type having a layer of a liquid crystal composition having a positive dielectric anisotropy accommodated between a first alignment film on a substrate and a second alignment film on the second substrate. In the active matrix type liquid crystal display device, in a region adjacent to the common electrode and the pixel electrode and located on the left and right, a direction from the first substrate of the liquid crystal director toward the liquid crystal is a direction approaching the common electrode and the pixel electrode. A liquid crystal display device characterized in that an effective panel gap is made thicker when an area on one side is compared with another area. 2. The structure in which the effective panel gap is thickened is that a slit extending parallel to the longitudinal direction of the electrode is provided in at least one of the gate insulating film and the protective insulating film. The liquid crystal display device as described in the above. 3. The liquid crystal display device according to claim 1, wherein the structure in which the effective panel gap is thickened is that a slit is partially provided in at least one of a gate insulating film and a protective insulating film. 4. The structure in which the effective panel gap is thickened, wherein a gate insulating film is formed in such a manner that a slit extending parallel to the longitudinal direction of the electrode partially overlaps the electrode.
2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided on at least one of the protective insulating films. 5. A structure for increasing an effective panel gap is provided in at least one of a gate insulating film and a protective insulating film in such a manner that a slit extending in parallel with a longitudinal direction of an electrode partially overlaps the electrode. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided partially. 6. The apparatus according to claim 1, wherein both the first transparent substrate and the second transparent substrate are glass substrates.
6. The liquid crystal display device according to any one of items 5 to 5. 7. The method for manufacturing a liquid crystal display device according to claim 1, wherein a slit parallel to a longitudinal direction of the electrode is formed at least partially in at least one of the gate insulating film and the protective insulating film. The manufacturing method characterized by the above-mentioned. 8. The method according to claim 7, wherein the slit is formed so as to partially overlap the electrode.