JPH11174493A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the image burning on a liquid crystal display device of an in-plane switching(IPS) mode. SOLUTION: Low-dielectric constant material layers 10 are formed in part of the space parts between driving electrode parts 8 and 9 of comb-shaped electrodes arranged on a first substrate 1. The dielectric constant of these low-dielectric constant material layers 10 is lower than the dielectric constant of the liquid crystals constituting a liquid crystal layer 3. As a result, the electric field intensity impressed on the liquid crystals at the boundary is lessened. High-dielectric constant material layers are otherwise formed on the surface of the substrate 1 and the electric field direction at the boundary is offset from the horizontal direction. A perpendicular surface is otherwise formed on the substrate of the display section or the horizontal parts in the display section are decreased, by which effective anchoring intensity is increased. As a result, the officiating of the liquid crystal molecules at the boundary from the direction of initial alignment at the time of driving voltage impression is substantially prevented and the image burning is prevented.

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 for displaying video and character information and a method for manufacturing the same, and more particularly, to a liquid crystal display device using an in-plane switching mode (IPS mode) and a method for manufacturing the same. About.

[0002]

2. Description of the Related Art Liquid crystal display devices have been widely used as flat displays for video equipment such as video movies and information equipment such as computers due to their thin and lightweight features. Many display modes have been proposed for the liquid crystal display. Among them, the in-plane switching mode (IPS mode) is disclosed in, for example, Japanese Patent Publication No. 5-505247 and Japanese Patent Application Laid-Open No. 6-273803. As shown in (1), display is performed by applying a parallel electric field to the substrate to switch the liquid crystal molecules in the in-plane direction of the substrate, and has a feature of having a wide viewing angle characteristic.

FIG. 21 is a plan view showing the overall configuration of an IPS mode liquid crystal display device. Comb-shaped signal electrode 51
And the common electrode 52 have a plurality of comb-shaped electrode portions, and these comb-shaped electrode portions are arranged in a meshing state. A scanning signal is applied to the scanning line 53 to make a thin film transistor (TFT).
When the switch 54 is turned on, the signal voltage from the signal line 55 is written to the signal electrode 51. The electric field in the horizontal direction of the substrate is generated due to the voltage difference between this and the common electrode 52, and the liquid crystal is switched. Reference numeral 56 denotes a common electrode bus line. In the figure, reference numeral 57 denotes a driving circuit on the scanning side, and 58 denotes a driving circuit on the signal side.

FIG. 22 is a sectional view taken along the line AA of FIG. In the figure, reference numerals 61 and 62 denote upper and lower substrates, which sandwich the liquid layer 63. Electrodes 51 and 52 are formed on the lower substrate 62. When a driving voltage is applied between the electrodes 51 and 52, an electric field parallel to the substrate is generated between the electrodes 51 and 52, and the liquid crystal operates by the electric field. 64 and 65 are alignment films for aligning liquid crystal molecules at the substrate interface, 66 and 67 are polarizing plates, and 70 is a light source.

[0005] When no voltage is applied, the liquid crystal molecules are in a parallel alignment state. When a liquid crystal having a positive dielectric anisotropy is used, the major axis of the liquid crystal molecules at the interface between the liquid crystal layer and the upper and lower substrates is substantially parallel to the direction in which the comb-shaped electrode extends (the horizontal direction in FIG. Then the depth direction of the paper)
Orientation. The polarization axes of the upper and lower polarizing plates 66 and 67 are orthogonal to each other, one is arranged in parallel with the orientation direction of the liquid crystal molecules, and the other is arranged perpendicular to it. The light emitted from the light source 70 is linearly polarized by the polarizing plate 67 and enters the liquid crystal layer 63.
The vibration direction of this linearly polarized light coincides with the major axis (or minor axis) of the liquid crystal molecules, and passes through the liquid crystal layer in the same polarization state. Since the polarization axis of the other polarizing plate 66 is orthogonal to the polarization direction of the light that has passed through the liquid crystal layer, the light is blocked here, and black display is performed.

When a voltage is applied between the electrodes 51 and 52, the liquid crystal molecules try to orient their long axes in the direction of the electric field. On the other hand, the liquid crystal molecules at the interface are bound by the alignment films 64 and 65. Due to the influence of both, the arrangement of the liquid crystal molecules at the time of applying a voltage becomes complicated, deviating from the parallel arrangement, and exhibits birefringence with respect to linearly polarized light that has passed through the polarizing plate 67 on the incident side.
Therefore, the state of polarization changes when passing through the liquid crystal layer. For this reason, a polarization component that passes through the polarizing plate 66 on the emission side is generated, and white display and halftone display are performed according to the applied voltage.

When a liquid crystal having a negative dielectric anisotropy is used, the liquid crystal molecules tend to have their minor axes oriented in the direction of the electric field. If the display is oriented so as to be substantially orthogonal to the display, the display is performed on the same principle.

[0008]

However, in the IPS mode liquid crystal display device configured as described above, the liquid crystal molecules at the substrate interface between the comb electrodes are rotated in the in-plane direction when an electric field is applied. And the power works. On the other hand, twist nematic
In the mode (TN mode), an electric field is applied between the two substrates, and a force acts to raise the liquid crystal molecules at the interface from within the plane. The anchoring strength of the liquid crystal molecules at the substrate interface is about one tenth to one hundredth of that in the direction in which the liquid crystal molecules rotate in the plane, compared to the anchoring in the direction in which the liquid crystal molecules tend to rise. It is. That is, the anchoring energy in the polar angle direction is 10 ⁻³ to 10 ⁻⁴ J / m.
² , the anchoring energy in the azimuthal direction is 10 ^-4 to 1
It is said to be about 0 ^-6 J / m ² . Therefore, in the IPS mode, the liquid crystal at the interface is more likely to deviate from the initial alignment direction in the portion where the electric field is applied than in the TN mode. Since this appears as a difference in the luminance-voltage characteristics, even if a voltage that should have the same luminance is applied, a difference in luminance occurs due to the previous display. That is, in the IPS mode, there is a problem that a so-called burn-in phenomenon easily occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device which solves the above-mentioned problems and prevents the occurrence of a so-called burn-in phenomenon, and a method of manufacturing the same.

[0010]

In order to achieve the above object, the invention according to claim 1 of the present invention comprises a first substrate, a second substrate facing the first substrate, a first substrate and a first substrate. A liquid crystal layer sandwiched between two substrates, a pair of drive electrodes provided corresponding to each pixel for applying an electric field to the liquid crystal layer to drive the liquid crystal layer to adjust light, and a pair of driving electrodes on the outer side of the first substrate. A pair of drive electrodes, comprising: a first polarizing plate to be disposed; and a second polarizing plate disposed outside the second substrate and having a polarization axis in a direction orthogonal to a polarization axis direction of the first polarization plate. Are both formed on the first substrate and configured to apply an electric field substantially parallel to the substrate. In the liquid crystal display device, of the electric field applied to the liquid crystal layer, portions other than the liquid crystal portion near the interface of the first substrate are included. While maintaining the electric field strength of the remaining liquid crystal part, only the electric field strength of the liquid crystal part near the interface of the first substrate is reduced. Characterized in that a Mel field suppression means.

According to the above configuration, only the electric field strength of the liquid crystal portion near the interface of the first substrate is weakened by the electric field suppressing means. Thereby, the torque for rotating the liquid crystal molecules at the interface in the horizontal direction when the driving voltage is applied is weakened, and the liquid crystal molecules are hardly shifted from the direction of the initial alignment, so that the burn-in phenomenon can be prevented. Even if the electric field intensity of the liquid crystal portion near the interface of the first substrate is reduced, the display characteristics are not affected as long as the electric field intensity of the remaining liquid crystal portion is maintained. Incidentally, for reference, if the electric field strength of the liquid crystal portion near the interface of the first substrate is weakened, a configuration in which the interval between the drive electrodes is widened is also conceivable. However, in the case of such a configuration, the electric field at the center of the liquid crystal layer is correspondingly weakened, and a display failure occurs. In order to eliminate the display failure, it is necessary to increase the electric field as compared with the case where the electrode interval is not increased, which is substantially the same as the case where the electrode interval is not increased. Therefore,
A configuration in which the distance between the drive electrodes is widened does not solve the problem.

According to a second aspect of the present invention, in the liquid crystal display device according to the first aspect, the pair of drive electrodes are comb-shaped electrodes each having a plurality of comb-teeth electrode portions, and the comb teeth of one of the drive electrodes are provided. It is characterized in that the electrode portion and the other comb-tooth electrode portion are arranged in an engaged state.

According to a third aspect of the present invention, in the liquid crystal display device according to the second aspect, the electric field suppressing means comprises a low dielectric constant material layer having a lower dielectric constant than a liquid crystal layer. It is characterized by being a configuration interposed between the parts.

According to the above configuration, since the electric field at the interface of the substrate is applied to the low dielectric constant material layer, the electric field applied to the liquid crystal at the interface of the substrate is weakened, so that there is an effect that image sticking does not occur.

According to a fourth aspect of the present invention, in the liquid crystal display device according to the second aspect, the electric field suppressing means includes a high dielectric constant material layer having a higher dielectric constant than the liquid crystal layer. The high dielectric constant material layer is formed at a portion corresponding to a portion between the electrode portions on the first substrate, and the upper surface of the high dielectric constant material layer is flush with the bottom surface of the drive electrode.

According to the above structure, the electric field at the substrate interface penetrates into the high dielectric constant material layer, so that the electric field intensity at the substrate interface is weakened or the electric field direction is shifted from the horizontal direction. For this reason, the horizontal electric field received by the liquid crystal at the substrate interface is weakened, and has the effect of preventing image sticking.

According to a fifth aspect of the present invention, in the liquid crystal display device of the second aspect, the electric field suppressing means includes a conductor buried in the first substrate, and the buried position of the conductor is in the meshing state. Position corresponding to each comb-tooth electrode part of
Alternatively, it is characterized in that it is configured to be located immediately below the comb-tooth electrode portion.

According to the above configuration, the electric field at the substrate interface penetrates into the conductor, so that the electric field intensity at the substrate interface is weakened or the electric field direction is shifted from the horizontal direction. For this reason, the horizontal electric field received by the liquid crystal at the substrate interface is weakened, and has the effect of preventing image sticking.

According to a sixth aspect of the present invention, in the liquid crystal display device of the second aspect, the electric field suppressing means protrudes and forms a mounting surface of the first substrate on which the comb-tooth electrode portion is mounted. It is characterized in that the bottom surface of the tooth electrode portion is positioned higher than the surface of the portion of the first substrate corresponding to the interdigitated comb tooth electrode portions.

According to the above configuration, the line connecting the two comb-teeth electrode portions having the strongest electric field in the horizontal direction is separated from the interface between the substrate and the liquid crystal layer, so that the electric field intensity at the substrate interface is weakened or the electric field direction is changed. Deviates from horizontal direction. For this reason, the horizontal electric field received by the liquid crystal at the substrate interface is weakened, and has the effect of preventing image sticking.

According to a seventh aspect of the present invention, in the liquid crystal display device according to the sixth aspect, the step surface of the first substrate connected to the mounting surface of the first substrate from the surface of the first substrate has a vertical surface. It is characterized by including.

According to the above configuration, since the step surface of the first substrate includes the vertical surface, the liquid crystal molecules at the interface of the vertical portion are rotated in the rising direction where the anchoring strength is strong when the driving voltage is applied. Torque works. Since the liquid crystal molecules at the interface hardly move even when the driving voltage is applied, the effect of the application of the driving voltage hardly remains on the liquid crystal molecules at the interface, so that there is an effect that image sticking does not occur.

According to an eighth aspect of the present invention, in the liquid crystal display device according to the second aspect, the electric field suppressing means is configured such that a comb electrode portion is embedded in the first substrate.

According to the above configuration, the comb-teeth electrode portion is formed by the first
By embedding in the substrate, the line connecting the two comb-teeth electrode parts with the strongest electric field in the horizontal direction moves into the substrate,
The electric field strength at the substrate interface is weakened, or the electric field direction is shifted from the horizontal direction. For this reason, the horizontal electric field received by the liquid crystal at the substrate interface is weakened, and has the effect of preventing image sticking.

According to a ninth aspect of the present invention, the first substrate comprises:
A second substrate facing the first substrate; a liquid crystal layer sandwiched between the first substrate and the second substrate; and a dimming drive of the liquid crystal layer by applying an electric field to the liquid crystal layer provided for each pixel. Drive electrodes, a first polarizing plate disposed on the outer side of the first substrate, and a polarizing axis disposed on the outer side of the second substrate and orthogonal to the direction of the polarizing axis of the first polarizing plate. And a pair of drive electrodes, both of which are formed on the first substrate and configured to apply an electric field substantially parallel to the substrate. A means for increasing the anchoring strength of the liquid crystal molecules in the in-plane rotation direction.

According to the above structure, the torque for rotating the liquid crystal molecules at the interface in the horizontal direction when the driving voltage is applied is reduced by the means for increasing the anchoring strength, so that the liquid crystal molecules are less likely to be displaced from the initial alignment direction, and the image sticking phenomenon is prevented. Can be prevented.

According to a tenth aspect of the present invention, in the liquid crystal display device according to the ninth aspect, the pair of drive electrodes are comb-shaped electrodes each having a plurality of comb-tooth electrode portions, and one of the drive electrodes is a comb-shaped electrode. It is characterized in that the electrode portion and the other comb-tooth electrode portion are arranged in an engaged state.

The invention according to claim 11 is the same as the claim 10.
In the liquid crystal display device described above, the means for increasing the anchoring strength is characterized in that a plurality of grooves are formed on the surface of the first substrate corresponding to each of the interdigitated comb-teeth electrode portions.

According to the above configuration, by forming a plurality of grooves on the surface of the first substrate corresponding to the space between the comb-tooth electrode portions, a vertical plane is formed in the liquid crystal alignment portion, and a driving electric field is prevented. By creating a part with high anchoring strength and reducing the horizontal plane of the liquid crystal alignment part to reduce the part with low anchoring strength against the driving electric field, the influence of the driving voltage applied to the liquid crystal molecules at the interface is less likely to remain. Has the effect that seizure does not occur.

The invention according to claim 12 provides the invention according to claim 11
In the liquid crystal display device described above, the side surface of the groove is a vertical surface.

According to the above-described structure, by forming a vertical surface on the side of the groove, a portion having a high anchoring strength with respect to the driving electric field is created, thereby having an effect of preventing image sticking.

The invention according to claim 13 provides the invention according to claim 11
In the liquid crystal display device described above, the groove has a V-shape.

According to the above configuration, by forming the groove in a V-shape, the portion having a low anchoring strength with respect to the driving electric field is reduced, so that the burn-in is prevented.

According to the invention of claim 14, claim 6 is
In the method for manufacturing a liquid crystal display device according to any one of 7, 11, 12, and 13, a pair of comb-shaped electrodes having a plurality of comb-teeth electrode portions is formed such that the comb-teeth electrode portions are arranged in an engaged state. A first step of forming on one substrate, a second step of processing the surface of a portion corresponding to a portion between the comb electrode portions of the first substrate into a predetermined shape, and a third step of performing an alignment process on the surface of the first substrate. A fourth step of performing an alignment process on the surface of the second substrate; and a fifth step of injecting a liquid crystal between the first substrate and the second substrate. It is characterized by the photo-alignment treatment used.

According to the above configuration, by performing the photo-alignment process on the substrate having the vertical surface or the inclined surface, it is possible to perform a sufficient alignment process on the vertical surface portion or the corner portion of the bend. And good and uniform orientation can be obtained.

The invention according to claim 15 is the invention according to claim 6,
In the method for manufacturing a liquid crystal display device according to any one of 7, 11, 12, and 13, a pair of comb-shaped electrodes having a plurality of comb-teeth electrode portions is formed such that the comb-teeth electrode portions are arranged in an engaged state. A first step of forming on one substrate, a second step of processing the surface of a portion corresponding to a portion between the comb electrode portions of the first substrate into a predetermined shape, and a third step of performing an alignment process on the surface of the first substrate. A fourth step of performing an alignment process on the surface of the second substrate, and a fifth step of injecting a liquid crystal between the first substrate and the second substrate, wherein the alignment process in the third step is a pull-up alignment process. It is characterized by being.

According to the above configuration, by performing the pull-up alignment process on the substrate having a vertical surface or an inclined surface, a sufficient alignment process can be performed even on a vertical surface portion or a corner portion of a bend. And good and uniform orientation can be obtained.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. (Embodiment 1) FIG. 1 is a sectional view showing a configuration of a liquid crystal display device according to a first embodiment of the present invention. In the figure, 1 is a first substrate, 2 is a second substrate, and these substrates 1
The liquid crystal layer 3 is sandwiched between the two. Reference numerals 4 and 5 denote alignment films for aligning the liquid crystal at the interface. A pair of drive electrodes 8 and 9 are formed on the first substrate 1. Drive electrodes 8, 9
Has the same configuration as the conventional example shown in FIG. That is, the drive electrodes 8 and 9 are respectively provided with a plurality of comb electrode portions 8A and 9
This is a comb-shaped electrode having A, and the comb-tooth electrode portion 8A and the comb-tooth electrode portion 9A are arranged in an engaged state. The liquid crystal layer 3 has a parallel arrangement structure as in the conventional example. In the case of a liquid crystal having a positive dielectric anisotropy, the direction in which the major axes of the liquid crystal molecules are arranged is substantially parallel to the direction in which the comb-teeth electrode portions 8A and 9A extend, and the liquid crystal having a negative dielectric anisotropy. In this case, the direction is substantially perpendicular to the direction in which the comb electrode portions 8A and 9A extend. A voltage is applied between the comb electrode portions 8A, 9A to deform the arrangement of the liquid crystal molecules, and the two second polarizing plates 6 and the first
Displaying using the polarizing plate 7 is the same as in the conventional example. Reference numeral 11 denotes a backlight for illumination.

The characteristics of the liquid crystal display device of this embodiment are as follows.
The low dielectric constant material layer 10 is formed between the comb electrode portions 8A and 9A on the substrate 1. This low dielectric constant material layer 10
Is lower than the dielectric constant of the liquid crystal constituting the liquid crystal layer 3. Hereinafter, the effect of the low dielectric constant material layer 10 will be described. FIG. 2 schematically shows electric lines of force and equipotential lines when a drive voltage is applied between the comb electrode portions 8A and 9A in a liquid crystal display device in which the low dielectric constant material layer 10 is not formed. . For the sake of simplicity, in the following description, the influence of the alignment films 4 and 5 will be omitted. Although a DC voltage is applied between the two comb-tooth electrode portions 8A and 9A to indicate an electric field in the figure, an AC voltage is applied when the liquid crystal is actually driven. These are the same in the description of the following embodiments. Since the vicinity of the surface of the first substrate 1 is the closest between the two comb-tooth electrode portions 8A and 9A, the electric field concentrates on this portion. Taking as an example the case where a liquid crystal having a positive dielectric anisotropy is used, the electric field causes the liquid crystal molecules oriented at the interface with the major axis directed in the depth direction of the paper to rotate so that the major axis is oriented in the horizontal direction. However, it is considered that this phenomenon is combined with the fact that the anchoring strength in the direction in which the liquid crystal is rotated is weak, resulting in a burn-in phenomenon.

FIG. 3 is a sectional view of the both-comb electrode portion 8 shown in FIG.
5 is an equivalent circuit schematically showing an electric capacity between A and 9A.
C1 to C3 represent the capacitance of the liquid crystal, and C4 represents the capacitance of the first substrate 1. When the low dielectric constant material layer 10 is formed at the edges of the comb-teeth electrode portions 8A and 9A, the electric capacitance of the low dielectric constant material layer 10 is provided at the equivalent circuit portion at the interface of the first substrate 1 as shown in FIG. C5 and C6 are inserted in series. Since the liquid crystal near the interface is partially replaced by the low dielectric constant material layer 10, the electric capacity of the liquid crystal also has a value C3 'different from that in FIG. The capacitances C1 and C2 of the liquid crystal other than near the interface and the capacitance C4 of the substrate 1 are not much different from those of FIG. Due to the effect of inserting C5 and C6 in series, the electric field applied to C3 'in FIG. 4 is lower than the electric field applied to C3 in FIG. FIG. 5 is for simply explaining this. Comb electrode part 8
Let S be the area of the side section of A · 9A, and it is approximated that the portion sandwiched by this section contributes to the electric capacity near the interface. The width of the low dielectric constant material layer 10 is d1 · d3, the width of the liquid crystal layer at the interface therebetween is d2, the interval between the comb-teeth electrodes is d, the dielectric constant of the liquid crystal is εLC, and the dielectric constant of the low dielectric constant material 10 is Let it be ε10.

First, considering the case where the low dielectric constant material layer 10 is not provided, the electric capacitance C3 at the interface portion is approximated by the following equation, where the vacuum dielectric constant is εo. C3 = .epsilon.o..epsilon.LC.S / d (Equation 1) Assuming that a voltage V is applied between the comb electrode portions 8A and 9A, the electric field applied to the liquid crystal at the interface when the low dielectric constant material layer 10 is not provided. Is as shown in (Equation 2). E1 = V / d (Equation 2) When the low dielectric constant material layer 10 is formed, the electric capacity of each part is as shown in (Equation 3) to (Equation 5). C3 '= εo · εLC · S / d2 (Equation 3) C5 = εo · ε10 · S / d1 (Equation 4) C6 = ・ o · ε10 · S / d3 (Equation 5) C3', C5 and C6 The voltage is V3 ', V
Assuming that V.sub.6 and V.sub.6, the distribution ratio is as follows from the equation of series connection of capacitors. V3 ': V5: V6 = (1 / C3'): (1 / C5): (1 / C6) (Equation 6) = (d2 / εLC): (d1 / ε10): (d3 / ε10) (Equation 7) )

When a voltage V is applied between the comb electrode portions 8A and 9A, V is distributed to each portion at a distribution ratio of (Equation 7). This distribution ratio is determined by the width and the dielectric constant of each part, and a large voltage is distributed to a portion where the width d is large and the dielectric constant ε is small. Since ε10 is smaller than εLC in the liquid crystal display device of the present embodiment, the second and third terms of (Equation 7) have the widths d1 and d3.
The distribution ratio is high Therefore, a large voltage is applied to the left and right low dielectric layers 10 for its width, and a small voltage is applied to the central liquid crystal for its width. That is, the relationship of (Equation 8) holds for the voltage applied to the liquid crystal portion near the interface. V3 '<V.d2 / (d1 + d2 + d3) (Equation 8) Since d is the sum of d1, d2, and d3, this can be rewritten as (Equation 9). V3 '<Vd2 / d (Equation 9) Assuming that the electric field applied to the liquid crystal portion near the interface is E2, this is obtained by dividing V3' by d2. Dividing both sides of (Equation 9) by d2 to find the equation for E2 gives
(Equation 10) and (Equation 11) can be obtained. V3 '/ d2 <V / d (Equation 10) E2 <E1 (Equation 11)

That is, it can be seen that the electric field intensity E2 applied to the liquid crystal near the interface when the low dielectric constant material layer 10 is formed is smaller than the electric field intensity E1 when no low dielectric constant material layer 10 is formed. As a result, the torque for rotating the liquid crystal at the substrate interface becomes weaker, and the liquid crystal at the interface becomes harder to move, so that image sticking hardly occurs. As a result, even when a constant display is performed for a long time, the display is not burned in, or even if it is burned, the degree of the burn is greatly reduced, and the recovery time is greatly shortened.

As is clear from (Equation 7), as εLC is larger and ε10 is smaller, the ratio of the voltage applied to the liquid crystal portion is reduced, and the above effect is enhanced. That is, when a voltage is applied between the electrodes and the liquid crystal begins to line up in the direction of the electric field, the ratio of the voltage applied to the liquid crystal portion is automatically reduced, thereby preventing image sticking.

As the low dielectric constant material layer 10, an SiO ₂ film formed by plasma CVD using tetraethoxysilane (TEOS) as a raw material can be used. In particular, C
If the film is formed in an F4 gas atmosphere, a film having a relative dielectric constant of 3 or less can be formed relatively easily. In addition, the above SiO ₂
Various fluorides may be used instead of the membrane.
In FIG. 1, the thickness of the low dielectric constant material layer 10 is smaller than that of the comb electrode portions 8A and 9A. In FIG. 5, the thickness of the low dielectric material layer 10 is equal to the thickness of the comb electrode portions 8A and 9A. Alternatively, it may be thicker than the comb electrode portions 8A, 9A. In order to efficiently weaken the electric field between the comb-tooth electrode portions 8A and 9A, it is desirable that the thickness of the low dielectric constant material layer 10 be equal to the thickness of the comb-tooth electrode portions 8A and 9A.

When the thickness of the low dielectric constant material layer is less than 1/10 of the inter-electrode interval d in FIG. 5, the voltage loss in this layer is small, so that the low dielectric constant material layer 10 is Even if it is formed over the entire edge and the upper surface of the electrode portion, there is no significant effect. On the other hand, when the thickness of the low dielectric constant material layer 10 is equal to or more than 1/10 of the electrode interval d in FIG. 5, the voltage loss here is large, so that the low dielectric constant material layer does not cover the entire surface of the electrode. It is desirable to do. Also, the position of the low dielectric constant material layer is not limited to the edge of the comb-teeth electrode portion. Even if this is formed at the center of the space between the electrodes, the electric field intensity applied to the liquid crystal at the interface is similarly weakened. Thus, occurrence of image sticking can be suppressed.

(Embodiment 2) FIG. 6 is a sectional view showing a configuration of a liquid crystal display device according to a second embodiment of the present invention. In the figure, the same components as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The orientation of the liquid crystal layer and the operation thereof are described in the conventional example and the first example.
This is the same as that described in the embodiment. The difference from the first embodiment is that the low dielectric constant material layer 10 in FIG. 1 is removed and the high dielectric constant material layer 21 is formed on the upper surface of the substrate 2. Also in this embodiment, the burn-in phenomenon is prevented by weakening the electric field applied to the liquid crystal near the substrate interface.

FIG. 7 schematically shows lines of electric force when a driving voltage is applied between the comb electrode portions 8A and 9A in order to show the effect of the high dielectric constant material layer 21. In this figure, the influence of the alignment films 4 and 5 is omitted for simplicity of description. In the present embodiment, the high-dielectric-constant material layer 21 and the liquid crystal layer 3 having a lower dielectric constant are arranged in parallel on the path of the lines of electric force from the comb-teeth electrode portion 8A to the comb-teeth electrode portion 9A. When materials having different dielectric constants are arranged in parallel, lines of electric force enter a material having a higher dielectric constant. As a result, the intensity of the electric field applied to the liquid crystal at the substrate interface weakens, or the direction of the electric field is oblique. Therefore, the torque for rotating the liquid crystal at the interface of the substrate in the horizontal direction is weakened, and the liquid crystal at the interface becomes difficult to move.
As a result, even when a constant display is performed for a long time, the display is not burned in, or even if it is burned, the degree of the burn is greatly reduced, and the recovery time is greatly shortened.

In the liquid crystal display device of this embodiment, after a high dielectric constant material such as TaOx (tantalum oxide) is formed on a glass substrate by a sputtering method or the like, the driving electrodes 8 and
9 can be manufactured. In order to draw the electric field on the surface of the first substrate 1 into the substrate 1, it is desirable that the thickness of the high dielectric constant material layer is at least １ ／ of the thickness of the comb electrode portion. If the thickness is at least half the thickness of the comb electrode portion, a more desirable effect can be obtained. 6 and 7, the high dielectric constant material layer 21 is present on the entire surface of the substrate 1, but the high dielectric constant material layer 21 is formed on the surface of the substrate 1 between the comb electrode portions 8A and 9A. The lower part of the comb-tooth electrode portions 8A and 9A may not be made of a material having a high dielectric constant.

(Embodiment 3) FIG. 8 is a sectional view showing a structure of a liquid crystal display device according to a third embodiment of the present invention. In the figure, the same components as those described in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted. The orientation of the liquid crystal layer and the operation thereof are the same as those described in the conventional example and the first embodiment. The liquid crystal display device of the present embodiment is obtained by removing the high dielectric constant material layer 21 of the second embodiment and forming a conductor 22 in the first substrate 1 instead. FIG. 9 shows the function of the conductor, schematically showing lines of electric force when a drive voltage is applied between the comb-tooth electrode portions 8A and 9A. The conductor 22 has an intermediate potential between the comb electrode portions 8A and 9A. As shown in the figure, of the lines of electric force that have come out of the comb electrode portion 8A, those that pass near the interface of the substrate 1 once enter the conductor 22 and then head toward the other comb electrode portion 9A. Become like That is, since there is no line of electric force directing the surface of the substrate 1 from the comb-teeth electrode portion 8A to the comb-teeth electrode portion 9A, the liquid crystal display device of the present embodiment also has an electric field applied to the liquid crystal at the interface of the substrate 1. Weakening,
The direction may be oblique.

Therefore, similarly to the second embodiment, the torque for rotating the liquid crystal at the interface of the substrate in the horizontal direction is weakened, and the liquid crystal at the interface becomes difficult to move. As a result, even when a constant display is performed for a long time, the display is not burned in, or even if it is burned, the degree of the burn is greatly reduced, and the recovery time is greatly shortened.

In FIG. 9, the conductor 22 has an intermediate potential between the comb electrode portions 8A and 9A. However, the present invention is not limited to this. For example, the potential of the conductor 22 is made to coincide with one of the potentials of the comb electrode portions 8A and 9A,
The effect described above can be obtained even in a floating state. For reference, when the conductor 22 is not set to the intermediate potential between the comb electrode portions 8A and 9A, the amount of electric lines of force traveling from the comb electrode portion 8A to the conductor 22 and the electric potential from the conductor 22 The amount of electric lines of force traveling to the comb-tooth electrode portion 9A is different, which may cause non-uniform display. Therefore, the conductor 22 is connected to the comb electrode portion 8.
It is desirable to configure so that an intermediate potential between A and 9A is obtained.

In FIGS. 8 and 9, the conductor 22 is formed in the middle of the comb electrode portions 8A, 9A. For example, as shown in FIG. 10, the conductor 22 is formed below the comb electrode portion 9A. Even if it is formed, the electric field near the interface can be weakened or directed obliquely, and the burn-in phenomenon can be prevented as in the above description. In this case, it is desirable that the potential of the conductor 22 be equal to the potential of the comb-tooth electrode portion 9A. When the conductor 22 is formed below the comb-tooth electrode portion 9A, it is desirable that the conductor 22 be closer to the edge of the comb-tooth electrode portion 9A. Because the comb electrode portion 9A
When the conductor 22 is formed near the lower central portion of the comb-teeth electrode portion 9A away from the edge of the comb-teeth electrode portion 9A, the amount of electric lines of force entering the conductor 22 from the comb-teeth electrode portion 8A is shielded by the comb-teeth electrode portion 9A. It is because it decreases.

When the conductor 22 is formed in an intermediate portion between the comb electrode portions 8A and 9A, it is desirable to form the conductor 22 from a transparent conductor in terms of brightness of the display device. On the other hand, when the conductor 22 is formed below the comb electrode portion 9A, there is an advantage that the brightness does not decrease even if a light-shielding metal is used. The conductor 22 is formed between the comb electrode portions 8A and 9A. However, it is not always necessary to have a stripe shape corresponding to the comb electrode portions 8A and 9A. FIG. 11 shows the comb electrode portion 8
FIG. 3 is a plan view showing an arrangement relationship between A and 9A and a conductor 22. In this figure, the conductors 22 are in the form of islands, and are arranged at intervals between the comb electrode portions 8A and 9A. In this way, as shown in the enlarged view of FIG. 12 showing the lines of electric force near the substrate interface, an electric field component in a direction parallel to the comb-shaped electrode (vertical direction in the figure) is generated at a portion where the conductor 22 is not provided, The liquid crystal near the interface in this portion hardly moves even when the driving voltage is applied. This serves as a nucleus to return the liquid crystal at the interface of the peripheral substrate to the original direction, so that there is an advantage that image sticking is more unlikely to occur. In addition, even when the transmittance of the conductor is low or when a light-blocking substance is used as the conductor, there is an advantage that the transmittance of the display device is relatively hard to decrease because the portion without the conductor 22 is wide. . Note that the liquid crystal display device of the present embodiment can be easily manufactured by forming the conductor 22 on the substrate 1, forming an insulating film having a predetermined thickness, and forming electrodes thereon.

(Embodiment 4) FIG. 13 is a sectional view showing a structure of a liquid crystal display device according to a fourth embodiment of the present invention.
In this figure, the same components as those described in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
The orientation of the liquid crystal layer and the operation thereof are the same as those described in the conventional example and the first embodiment. The liquid crystal display device of the present embodiment is different from the conventional liquid crystal display device in that the first substrate 1 is provided with the protruding portion 23, on which the comb electrode portions 8A and 9A are formed.

FIG. 14 schematically shows lines of electric force near the surface of the substrate 1 in the liquid crystal display device of the present embodiment. With the configuration of the present embodiment, the comb-teeth electrode portion 8A and the comb-teeth electrode portion 9A having the strongest electric field in the horizontal direction are provided.
Can be separated from the interface between the substrate 1 and the liquid crystal layer 3. As a result, the intensity of the electric field applied to the liquid crystal at the substrate interface weakens, or the direction of the electric field is directed obliquely, and the liquid crystal at the substrate interface is rotated in the horizontal direction, as described in the above embodiment. The liquid crystal at the interface becomes difficult to move.

Further, in the liquid crystal display device of the present embodiment, if both side surfaces of the protruding portion 23 are perpendicular to the substrate 1, it is advantageous for image sticking for the following reasons. In FIG. 14, reference numeral 25 denotes a liquid crystal molecule. The liquid crystal molecules 25 are oriented at each interface with the long axis directed in the front-to-depth direction on the paper. The figure shows the liquid crystal molecules 25 at the interface of the groove 26 on the substrate 1. When a driving voltage is applied between the comb electrode portions 8A and 9A, among the liquid crystal molecules 25 shown in the drawing, the liquid crystal molecules at the interface with the bottom 26A of the groove 26 will rotate the liquid crystal molecules with respect to the interface (horizontal plane). In-plane torque acts. On the other hand, a torque acts on the liquid crystal molecules 25 at the interface between the left and right side walls 26B of the groove 26 so as to cause the liquid crystal molecules 25 to rise from the side wall 26B interface (vertical surface). As described above, since the anchoring strength in the direction in which the liquid crystal rises from the interface is very strong, the liquid crystal molecules 25 at the interface between the left and right side walls 26B of the groove hardly move even when the driving voltage is applied. Therefore, the bottom 26
Even when the alignment direction of the liquid crystal molecules 25 of A is shifted, the side wall 2
Since the orientation of the portion 6B serves as a nucleus to return its orientation to the original direction, or the orientation near the left and right side walls 26B is arranged so as to wrap around the exit portion of the groove 26, so that the bottom portion 26A
Even if the nearby alignment state propagates upward, it is cut off at the exit portion of the groove 26 and exerts a so-called masking effect of preventing further propagation upward, so that the seizure phenomenon hardly occurs. In the above description, the dielectric anisotropy of the liquid crystal is assumed to be positive.

By the two effects described above, even when a fixed display is performed for a long time, the display is not burned in, or even if it is burned, the degree of the burn is greatly reduced and the recovery time is greatly shortened.

When a liquid crystal having a negative dielectric anisotropy is used in the configuration of the present embodiment, it is necessary to initially align the liquid crystal molecules in FIG. In this case, it is necessary that the long axis of the liquid crystal is oriented parallel to the interface at the bottom of the groove and the long axis of the liquid crystal is oriented perpendicular to the interface at the side wall of the groove.
When a liquid crystal having a negative dielectric anisotropy is used, it is necessary to perform an alignment treatment having two kinds of characteristics according to the plane. On the other hand, when a liquid crystal having a positive dielectric anisotropy is used, the long axis of the liquid crystal may be aligned parallel to the interface at both the bottom and the side wall of the groove, and the alignment process is simple. Therefore, in the liquid crystal display device of the present embodiment, it is desirable to use liquid crystal having a positive dielectric anisotropy.

The protruding portion of the liquid crystal display device of the present embodiment may be formed of a substrate glass, or may be formed of another insulating film formed on the substrate glass. As the insulating film, SiNx (silicon nitride) or the like can be used. In any case, a projection pattern may be formed on a glass substrate in advance, and an electrode pattern may be formed thereon. However, it is desirable to use a self-alignment technique as described below in terms of pattern accuracy. That is, after forming the patterns of the drive electrodes 8 and 9 on the substrate 1 with a metal such as chromium, a photoresist is applied thereon. Electrode 8,
Since 9 is opaque, a resist pattern can be formed with high accuracy by performing exposure from the back. If etching is performed using this resist pattern, the protrusions 23 can be accurately left.

As another method, there is a method of forming patterns of the drive electrodes 8 and 9 on the substrate 1 with a metal such as chromium and then etching the substrate 1 using the drive electrodes 8 and 9 as a mask. In this case, not only can the protrusions 23 be manufactured with high accuracy, but also the protrusions 23 can be formed.
Since a photolithography step for forming is not required, there is an advantage that yield can be improved and cost can be reduced.

(Embodiment 5) FIG. 15 is a sectional view showing the structure of a liquid crystal display device according to a fifth embodiment of the present invention.
In this figure, the same components as those described in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.
The orientation of the liquid crystal layer and the operation thereof are the same as those described in the conventional example and the first embodiment. The liquid crystal display device of the present embodiment is formed by embedding the drive electrodes 8 and 9 in the substrate 1 in the conventional liquid crystal display device. With such a configuration, a region where the electric field intensity is maximum, that is, a line connecting the comb-teeth electrode portion 8A and the comb-teeth electrode portion 9A can be moved to the inside of the substrate 1. As a result, the intensity of the electric field applied to the liquid crystal at the substrate interface weakens, or the direction of the electric field is directed obliquely, and the liquid crystal at the substrate interface is rotated in the horizontal direction, as described in the above embodiment. The liquid crystal at the interface becomes difficult to move. As a result, even if a fixed display is performed for a long time, the display does not burn,
Even if it burns in, the extent is greatly reduced and the recovery time is greatly reduced. In the liquid crystal display device of the present embodiment, after forming the comb-shaped electrode, an insulating film may be formed thereon. In FIG. 15, the upper and lower portions of the comb electrode portions 8A and 9A are made of the same material, but different materials may be used. The depth at which the electrodes are embedded is preferably at least 1/10 of the width of the space between the electrodes. 1/1
If it is less than 0, the effect of reducing the intensity of the electric field applied to the liquid crystal at the substrate interface is too small to prevent image sticking.

(Embodiment 6) FIG. 16 is a sectional view showing the structure of a substrate with electrodes of a liquid crystal display according to a sixth embodiment of the present invention. In this figure, the same components as those described in the above embodiment are denoted by the same reference numerals, and description thereof is omitted. The substrate 1 with electrodes is a substrate 2 on the opposite side.
For example, a liquid crystal display device as shown in a sectional view in FIG. In this embodiment, by forming a vertical surface at the substrate interface,
This is to increase the anchoring strength of the liquid crystal molecules so that the image sticking phenomenon does not occur.

FIG. 16 shows a preferred configuration when a liquid crystal having a positive dielectric anisotropy is used. In the figure, the surfaces of the substrate 1 and the comb electrode portions 8A, 9A are:
Although not shown, an alignment film is formed. A groove 24 is formed on the surface of the substrate 1 between the comb electrode portions 8A and 9A. At any interface between the bottom 24A and the side wall 24B of the groove 24, the long axis of the liquid crystal molecules is
A and 9A are oriented in a direction parallel to the extending direction. When a drive voltage is applied between the comb electrode portions 8A and 9A, the liquid crystal molecules tend to direct their long axes in the direction of the electric field.
That is, as in the case shown in FIG.
At the 4A interface, torque acts to rotate the liquid crystal molecules in the in-plane direction of the interface (horizontal plane), and at the side wall 24B of the groove 24, torque acts to cause the liquid crystal molecules to rise from the interface (vertical plane). As in the description of the fourth embodiment, since the anchoring strength in the direction in which the liquid crystal rises from the interface is very strong, the liquid crystal molecules on the left and right side wall interfaces of the groove hardly move even when the driving voltage is applied.

Therefore, even when the alignment direction of the liquid crystal molecules in the bottom portion 24A is shifted, the alignment of the side wall 24B becomes a nucleus and the alignment direction is returned to the original direction, or the left and right side walls 2
Since the orientation of 4B is arranged so as to surround the exit portion of the groove 24, a so-called masking effect is exerted on the orientation of the bottom portion 24A, so that the seizure phenomenon hardly occurs. As a result, even when a constant display is performed for a long time, the display is not burned in, or even if it is burned, the degree of the burn is greatly reduced, and the recovery time is greatly shortened.

When the liquid crystal display device of the present embodiment is used in combination with a liquid crystal having a negative dielectric anisotropy, the groove 24 is formed so as to be orthogonal to the extending direction of the comb-teeth electrode portions 8A and 9A. It is preferable that the liquid crystal molecules are oriented in such a manner that the major axis of the liquid crystal molecules is oriented in this direction. In this case, the long axis of the liquid crystal may be aligned parallel to the interface at both the bottom and the side wall of the groove 24, and there is no need to mix the parallel alignment plane and the vertical alignment plane. In the above description, the side surface 24B of the groove is a vertical surface, but it may be a V-shaped groove. In this case, the horizontal surface at the bottom of the groove can be eliminated. The liquid crystal molecules at the interface of the horizontal plane are subjected to a torque for rotating the liquid crystal molecules in the plane, but the anchoring strength in this direction is weaker than in other directions. If a V-shaped groove is formed, no liquid crystal molecules receive torque completely in the in-plane direction inside the groove, and the anchoring strength can be effectively increased.
As a result, the influence of the application of the driving voltage is less likely to remain on the liquid crystal molecules at the interface, so that image sticking does not occur or hardly occurs. Further, as shown in FIG. 17, if the horizontal portion between the grooves 24 is formed into a mountain shape and has a saw-tooth cross section as a whole, there is no horizontal plane at all, so that image sticking can be further reduced.

The vertical surfaces and grooves on the substrate described above may be formed by etching, but may also be formed by using an ultraviolet curable resin. That is, if a UV-curable resin is applied on a substrate, and the resin is irradiated with UV light from the glass substrate while being pressed with a mold having a surface processed into a predetermined shape, the substrate surface can be processed into a predetermined shape. . still,
A thermosetting resin may be used instead of the ultraviolet curable resin, and the surface shape may be formed by curing with heat.

(Embodiment 7) In the liquid crystal display device according to the fourth or sixth embodiment including a surface perpendicular to the surface of the substrate 1 with electrodes, when the photo-alignment treatment by polarized UV light is performed, A good alignment state was obtained. When polarized UV light is irradiated only from the normal direction of the substrate, the irradiation is performed at a very shallow angle on the vertical surface, so that sufficient light does not hit or a portion that becomes a shadow of the electrode is generated. In the present embodiment, after irradiating polarized UV light from the substrate normal direction, as shown in FIG.
The substrate 1 was rotated about an axis 32 parallel to the direction in which A extends, so that the polarized UV light 31 was sufficiently applied to all regions.

When the substrate including the vertical surface is oriented by the rubbing method, the rubbing cloth does not sufficiently contact the vertical surface and the corners of the bend, which may cause poor alignment. As described above, when the photo-alignment was used, a very good and uniform alignment including a vertical plane and a corner portion could be obtained. Note that the light source may be moved instead of rotating the substrate in order to eliminate an insufficiently irradiated region. When a liquid crystal having a negative dielectric anisotropy is used in the sixth embodiment, the direction of the groove formed on the substrate is perpendicular to the direction in which the electrodes extend. In such a case, it is desirable to perform the second rotation of the substrate around another axis parallel to the substrate surface and orthogonal to the axis 32.

Further, even if a pull-up alignment treatment using an LB film or a chemical adsorption film is used instead of the photo-alignment, a good and uniform alignment treatment can be performed on a substrate including a vertical surface. Here, the pull-up orientation treatment is performed as shown in FIG.
As shown in FIG. 19A, a thin film 33 having a structure in which chain-like molecules extend in a certain direction is floated on the surface of water 34, and a substrate 35 to be subjected to alignment treatment is pulled up from the state of being immersed in water, thereby obtaining FIG. As shown in (1), this refers to a processing method in which the thin film 33 adheres to the surface of the substrate 35, and as a result, the surface of the substrate 35 is subjected to an alignment process.

When the liquid crystal display device of the fourth embodiment is manufactured by this pulling-up alignment process, the comb-tooth electrode portion 8
In the case of manufacturing the liquid crystal display device of the sixth embodiment, the major axis of the liquid crystal molecules is oriented parallel to the direction in which A and 9A extend. The pull-up direction may be determined so that is oriented. Also in the case of using the pull-up alignment treatment, very good and uniform alignment including the vertical plane and the corners could be obtained as in the case of the optical alignment.

In the first to sixth embodiments, the burn-in phenomenon can be prevented or hardly caused by the substrate structure of the liquid crystal display device. However, when some of these structures are used in combination, it is more favorable. Effects can be achieved. For example, as shown in FIG.
If 0 is also formed below the electrodes 8 and 9, the effect of the first and fourth embodiments is combined to move the portion where the electric field is strongest from the interface between the substrate 1 and the liquid crystal layer 3 to the inside of the liquid crystal layer 3. Let
In addition, the intensity of the electric field applied to the liquid crystal layer at the interface can be further reduced. As a result, it was possible to prevent or prevent the image sticking phenomenon even under severer voltage, time and temperature conditions. The combinations of the embodiments are not limited to those described above, and other combinations and combinations of three or more are also effective. In the first to sixth embodiments, comb electrodes are used as drive electrodes. However, the present invention is not limited to this, and a plurality of strip-shaped electrodes may be used. As for the comb electrode, although the comb electrode portion was linear,
In this case, the rotation direction of the liquid crystal is opposite on both sides of the bent portion, so that the viewing angle characteristics are symmetrical and a display that is more easily viewable is obtained. be able to.

[0073]

As described above, according to the present invention, the structure provided with the electric field suppressing means for weakening only the electric field of the liquid crystal portion near the interface of the first substrate or the in-plane of the liquid crystal molecules at the interface of the first substrate is provided. By providing a means for increasing the anchoring strength in the rotation direction, the torque for rotating the liquid crystal molecules at the interface in the horizontal direction when a driving voltage is applied is reduced, and the liquid crystal molecules are hardly displaced from the initial alignment direction, thereby preventing the image sticking phenomenon. be able to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing electric lines of force and electric potential lines of a conventional liquid crystal display device.

FIG. 3 is a cross-sectional view schematically showing an equivalent circuit between electrodes of a conventional liquid crystal display device.

FIG. 4 is a sectional view schematically showing an equivalent circuit between electrodes of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a configuration near a substrate of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view schematically illustrating a configuration near a substrate and lines of electric force of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 8 is a sectional view illustrating a configuration of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 9 is a cross-sectional view schematically illustrating a configuration near a substrate and lines of electric force of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view schematically illustrating a configuration near a substrate and lines of electric force of a liquid crystal display device according to a modification of the third embodiment of the present invention.

FIG. 11 is a plan view showing an arrangement of electrodes and conductors of a liquid crystal display according to another modification of the third embodiment of the present invention.

FIG. 12 is a plan view schematically showing directions of lines of electric force in FIG.

FIG. 13 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 14 is a cross-sectional view schematically illustrating a configuration near a substrate, lines of electric force, and liquid crystal molecules at an interface of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 15 is a sectional view illustrating a configuration of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 16 is a perspective view illustrating a substrate configuration of a liquid crystal display device according to a sixth embodiment of the present invention.

FIG. 17 is a perspective view showing a substrate configuration of a liquid crystal display device according to another modification of the sixth embodiment of the present invention.

FIG. 18 is a perspective view illustrating the method for manufacturing the liquid crystal display device according to the seventh embodiment of the present invention.

FIG. 19 is a diagram for explaining a pulling alignment process.

FIG. 20 is a sectional view showing a configuration of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 21 is a plan view showing the overall configuration of a conventional liquid crystal display device.

22 is a sectional view taken along the line AA of FIG. 21.

[Explanation of symbols]

 1: First substrate 2: Second substrate 3: Liquid crystal layer 4, 5: Alignment film 6, 7: Polarizer 8, 9: Driving electrode 8A, 9A: Comb-tooth electrode portion 10: Low dielectric constant material layer 21: High Dielectric substance layer 22: Conductor 23: Projecting portion of substrate 24, 26: Groove 25: Liquid crystal molecule 31: Polarized UV light

Claims (15)

[Claims] 1. A first substrate, a second substrate facing the first substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate, and an electric field applied to the liquid crystal layer provided for each pixel. A pair of driving electrodes for applying light to drive the liquid crystal layer by dimming, a first polarizer disposed outside the first substrate, and a first polarizer disposed outside the second substrate. A second polarizing plate having a polarization axis in a direction orthogonal to the polarization axis direction, wherein the pair of drive electrodes are both formed on a first substrate and configured to apply an electric field substantially parallel to the substrate. In the display device, of the electric field applied to the liquid crystal layer, the electric field intensity of the remaining liquid crystal portion other than the liquid crystal portion near the interface of the first substrate is maintained, and the electric field intensity of the liquid crystal portion near the interface of the first substrate is maintained. A liquid crystal display device comprising an electric field suppressing means for weakening only the electric field. 2. The pair of drive electrodes are comb electrodes each having a plurality of comb electrode portions, and the comb electrode portion of one drive electrode and the other comb electrode portion are arranged in an engaged state. The liquid crystal display device according to claim 1. 3. The liquid crystal display device according to claim 2, wherein said electric field suppressing means has a structure in which a low dielectric constant material layer having a lower dielectric constant than a liquid crystal layer is interposed between said interdigitated comb-teeth electrode portions. . 4. The electric field suppressing means, wherein a high dielectric constant material layer having a higher dielectric constant than the liquid crystal layer is formed at a portion on the first substrate corresponding to between the interdigitated comb-shaped electrode portions;
3. The liquid crystal display device according to claim 2, wherein an upper surface of the high dielectric constant material layer is flush with a bottom surface of the drive electrode. 5. The electric field suppressing unit according to claim 1, wherein a conductor is buried in the first substrate, and the buried position of the conductor is a position corresponding to each of the interdigitated comb-teeth electrode portions, or a comb-teeth electrode. 3. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is configured to be located immediately below the portion. 6. An electric field suppressing means, wherein a mounting surface of a first substrate on which a comb-tooth electrode portion is mounted is formed so as to protrude, and a bottom surface of the comb-tooth electrode portion is disposed between the interdigitated comb-tooth electrode portions. 3. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is configured to be located at a position higher than the surface of the portion of the first substrate corresponding thereto. 7. The liquid crystal display device according to claim 6, wherein a step surface of the first substrate connected to a mounting surface of the first substrate from a partial surface of the first substrate includes a vertical surface. 8. The electric field suppressing means according to claim 1, wherein the comb electrode portion comprises:
3. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is embedded in the first substrate. 9. A first substrate, a second substrate facing the first substrate, a liquid crystal layer sandwiched between the first substrate and the second substrate, and an electric field applied to the liquid crystal layer provided for each pixel. A pair of driving electrodes for applying light to drive the liquid crystal layer by dimming, a first polarizer disposed outside the first substrate, and a first polarizer disposed outside the second substrate. A second polarizing plate having a polarization axis in a direction orthogonal to the polarization axis direction, wherein the pair of drive electrodes are both formed on a first substrate and configured to apply an electric field substantially parallel to the substrate. A display device, comprising: means for increasing anchoring strength in an in-plane rotation direction of liquid crystal molecules at an interface of the first substrate. 10. The pair of drive electrodes are comb electrodes each having a plurality of comb electrode portions, and the comb electrode portion of one drive electrode and the other comb electrode portion are arranged in an engaged state. The liquid crystal display device according to claim 9. 11. The device according to claim 10, wherein the means for increasing the anchoring strength is such that a plurality of grooves are formed on the surface of the portion of the first substrate corresponding to each of the interdigitated comb-teeth electrode portions. Liquid crystal display. 12. The liquid crystal display device according to claim 11, wherein a side surface of the groove is a vertical surface. 13. The groove according to claim 1, wherein said groove has a V-shape.
2. The liquid crystal display device according to 1. 14. A first step of forming a pair of comb-shaped electrodes having a plurality of comb-tooth electrode portions on a first substrate so that the comb-tooth electrode portions are engaged with each other; A second step of processing the surface of the portion corresponding to between the electrode portions into a predetermined shape, a third step of performing an alignment process on the surface of the first substrate, a fourth step of performing an alignment process on the surface of the second substrate, A fifth step of injecting a liquid crystal between the first substrate and the second substrate; and wherein the alignment processing in the third step is a light alignment processing using polarized ultraviolet light. , 13
The method for manufacturing a liquid crystal display device according to any one of the above. 15. A first step of forming a pair of comb-shaped electrodes having a plurality of comb-tooth electrode portions on a first substrate so that the comb-tooth electrode portions are engaged with each other; A second step of processing the surface of the portion corresponding to between the electrode portions into a predetermined shape, a third step of performing an alignment process on the surface of the first substrate, a fourth step of performing an alignment process on the surface of the second substrate, A fifth step of injecting a liquid crystal between the first substrate and the second substrate, wherein the alignment processing in the third step is a pull-up alignment processing. 3. The method for manufacturing a liquid crystal display device according to item 1.