JP3408134B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a large-sized liquid crystal display device suitable for application to a high-definition television such as HDTV or a display for CAD.

[0002]

2. Description of the Related Art As a method of improving the viewing angle characteristics of a liquid crystal display device, a display mode (Axially Symmetric A) in which liquid crystal molecules are aligned axially symmetrically for each picture element is used.
Signed Microcell Mode: ASM
Mode) is disclosed in JP-A-7-120728. This method is a technique for orienting liquid crystal molecules in an axially symmetrical manner by utilizing phase separation from a mixture of a liquid crystal material and a photo-curable resin. This is a p-type display mode in which liquid layer molecules oriented in the direction are oriented perpendicular to the substrate.

Another technique is Japanese Patent Application No. 8-341.
590, a pair of substrates each having an electrode and a liquid crystal layer sandwiched between the pair of substrates, the liquid crystal molecules of the liquid crystal layer have a negative dielectric anisotropy, When no output voltage is applied, the liquid crystal molecules are aligned vertically with respect to the pair of substrates, and the liquid crystal molecules are axially symmetric in each of a plurality of pixel regions when the center axis alignment voltage is applied. There is disclosed a liquid crystal display device which is oriented in a vertical direction. Since the proposed liquid crystal display device operates in the normally black mode, it is possible to obtain a higher contrast than the conventional ASM mode liquid crystal display device, and it is possible to easily manufacture the liquid crystal display device.

FIG. 9 shows a schematic diagram of a conventional n-type ASM liquid crystal display device. 9 (b) is a plan view thereof, and FIG. 9 (a) is a sectional view taken along line XX of FIG. 9 (b).

This liquid crystal display device has a glass substrate 101 and a glass substrate 102, which are arranged to face each other with a predetermined gap, and a space between the substrates 101 and 102 is made of a liquid crystal material having a negative dielectric anisotropy. The liquid crystal layer 109 is sandwiched. Signal electrodes 104 are formed in stripes on the inner surface of the glass substrate 102 on the upper side of the figure, and a vertical alignment layer 105 made of polyimide or the like is formed on almost the entire surface to cover the signal electrodes 104.

On the inner surface of the glass substrate 101 on the lower side of the drawing, signal electrodes 103 are formed in a stripe shape so as to intersect with the signal electrodes 104, and grid-shaped partition walls 106 are further formed thereon. The columnar protrusions 107 are provided on the partition wall 106 selectively and on the glass substrate 10 on the upper side of the drawing.
It is provided to reach 2.

The partition wall 106 is formed by patterning, for example, by exposing and developing a photosensitive resin through a mask, and the columnar projections 107 are made of, for example, a photosensitive resin through a mask similarly to the partition wall 106. Then, it is exposed and developed to form a pattern. Above these signal electrodes 103, partition walls 106 and columnar protrusions 107,
A vertical alignment layer 105 made of polyimide or the like is covered.

In this technique, the partition wall 106 defines the position and size of the liquid crystal region 108.
The portion surrounded by the partition wall 106 becomes the liquid crystal region 108, and when no voltage is applied between the signal electrodes 103 and 104, the liquid crystal molecules in the liquid crystal region 108 form a pair of substrates 101,
The liquid crystal molecules are aligned substantially perpendicular to 102, and the liquid crystal molecules are oriented in axial symmetry in each liquid crystal region 108 when a voltage is applied. Also,
Columnar protrusion 1 existing between the partition wall 106 and the substrate 102
07 has a function of keeping the cell thickness constant because it is in contact with the substrate 102.

The configuration and operating principle of this liquid crystal display device will be described with reference to FIG. 10 (a) and 10 (b) show a case where no axial centering alignment centering voltage is applied, and FIGS. 10 (c) and 10 (d) show a case where axis symmetrical alignment centering voltage is applied. 10 (a) and 10 (c) are sectional views, and FIGS. 10 (b) and 10 (d) show the results obtained by observing the upper surface with a polarization microscope in the crossed Nicols state.

In this liquid crystal display device, a liquid crystal layer 140 composed of liquid crystal molecules 142 having a negative dielectric anisotropy is sandwiched between a pair of substrates 132 and 134. Transparent electrodes 131 and 133 are formed on the surfaces of the pair of substrates 132 and 134 in contact with the liquid crystal layer 140, respectively, and vertical alignment layers 138a and 138b are further formed thereon. Further, a projection 136 is formed on the surface of at least one of the pair of substrates 132 and 134 that is in contact with the liquid crystal layer 140.

As will be described later, the projection 136 defines a region having an axially symmetric orientation when a central axis-aligning voltage is applied. Therefore, as shown in FIG. 10 (c), the protrusion 136 is centered on the axially symmetrical orientation central axis 144.
The liquid crystal molecules 142 are axisymmetrically aligned in the pixel region defined by

When no axial centering voltage is applied, the liquid crystal molecules 142 are aligned in the direction perpendicular to the substrate due to the alignment regulating force of the vertical alignment layer, as shown in FIG. When a picture element region in which no axially centering voltage is applied with an axially symmetric orientation is observed with a crossed Nicols polarization microscope, a dark field is exhibited as shown in FIG. 10B (normally black mode). Liquid crystal molecules 14 having a negative dielectric anisotropy when an axially symmetrical alignment centering voltage is applied.
Since a force for orienting the long axes of the liquid crystal molecules perpendicularly to the direction of the electric field acts on 2, the liquid crystal molecules tilt from the direction perpendicular to the substrate as shown in FIG. 10C (halftone display state). When observing the picture element area in this state with a crossed Nicols polarization microscope,
As shown in FIG. 10D, an extinction pattern is observed in the direction along the polarization axis.

FIG. 11 shows a voltage transmittance curve of the above liquid crystal display device.

The transmittance gradually increases as a voltage is applied, and the transmittance reaches saturation as the voltage further increases. The voltage at which the transmittance is saturated is called the saturation voltage (Vst). A voltage at which the transmittance is 10% relative to the transmittance at Vst (saturation voltage) is called Vth (threshold voltage). When voltage is applied from the state where no voltage is applied, the liquid crystal molecules tilt from the direction perpendicular to the substrate.
Since the tilt direction is not uniquely determined, a plurality of axially symmetrical alignment central axes are formed in the liquid crystal region that exhibits the axially symmetrical alignment defined by the protrusion 136. The state in which a plurality of axially symmetrical alignment central axes exist is an unstable alignment state and the transmittance is not stable. When a voltage of 1/2 Vth or more is continuously applied, a plurality of axisymmetric alignment center axes that exist are provided for each liquid crystal region defined by the protrusion 136. When the voltage applied to the liquid crystal layer 140 is between 1/2 Vth and Vst, the transmittance reversibly changes within the operating range shown in FIG. In the state where a voltage near 1/2 Vth is applied, the liquid crystal molecules are almost vertically aligned with respect to the substrate, and when the voltage of 1/2 Vth or more is applied, that is, the axially symmetric alignment state, that is, the axially symmetric alignment. It remembers the symmetry about the central axis. However, no voltage is applied or the applied voltage is 1/2 Vth.
When it becomes lower than the above, the liquid crystal molecules are almost vertically aligned with respect to the substrate and return to the state in which the axially symmetric alignment state is not stored. Even if a voltage of 1/2 Vth or more is applied again from this state, a plurality of axis-symmetric alignment center axes are once formed. For example, when an n-type liquid crystal material is injected into the liquid crystal cell, the same behavior is exhibited.

As described above, in the liquid crystal display device, when no voltage is applied, the liquid crystal molecules are oriented in the direction perpendicular to the substrate to provide black display, and when voltage is applied, the liquid crystal molecules are formed in each pixel region. Symmetrical Alignment It operates in a normally black mode in which an axisymmetric alignment state is formed around the central axis and white display is performed. However, since a plurality of axis-symmetric alignment center axes are formed immediately after the voltage is applied, the operation becomes unstable when the voltage is not applied in black display. In order to perform stable operation in the display mode of this liquid crystal display device, it is desirable to form one axis-symmetric alignment center axis for each pixel area in advance before performing the display operation.

Before the display operation, one axisymmetric alignment center axis is formed for each pixel region in advance.
A constant voltage, that is, a voltage of 1/2 Vth or more may be applied. In this way, only one axis-symmetrical alignment central axis is formed for each pixel region, and a stable axis-symmetrical alignment state is realized during white display. However, once no voltage is applied, the initial unstable state in which a plurality of axially-symmetric alignment central axes are formed is returned. Therefore, after the display is started, even in black display, no voltage is applied. Instead, it is used in a state where a constant voltage, that is, a voltage near 1/2 Vth is applied. In this display mode, the operating voltage is used in a voltage range (a voltage of 1/2 Vth or more and a voltage of Vst or less) in which a stable axially symmetric orientation state is obtained.

Further, at the time of applying a voltage, in order to stably orient the liquid crystal molecules in each pixel region in an axially symmetrical manner, at least the surface of the substrate in contact with the liquid crystal layer in the region corresponding to the liquid crystal region, Disclosed is a technique of providing an axially symmetric orientation fixed layer made of a polymer material. The formation of this axially symmetric alignment fixing layer is realized by placing a precursor mixture consisting of at least a liquid crystal material and a photocurable material between a pair of substrates and curing the mixture while applying a voltage. it can. The applied voltage may be 1/2 Vth or more, which stabilizes the above-mentioned axially symmetric orientation, and Vst or less.

[0018]

However, when applied to the above-mentioned conventional large-sized display device, there are the following problems.

In general, ITO is used for the transparent electrode, and ITO has a high resistivity, and the larger the screen, the more uneven the applied voltage applied to the liquid crystal layer in the panel.

In the above-mentioned conventional display mode, the operating voltage is used within a voltage range (a voltage of 1/2 Vth or more and a voltage of Vst or less) that can provide a stable axially symmetric orientation state. When the screen is made larger, the non-uniformity of the voltage applied in the black display becomes large in the panel, and there is a pixel in which a stable axially symmetric orientation state cannot be obtained, because a voltage of 1/2 Vth or less is applied. However, the display becomes uneven, which causes roughness. To eliminate the display unevenness, it was necessary to increase the driving voltage.

Further, in a further conventional technique, a precursor mixture consisting of at least a liquid crystal material and a photo-curable material is cured while applying a voltage, whereby a region corresponding to the liquid crystal region of at least one of the substrates. An axisymmetric alignment fixing layer made of a polymer material is formed on the surface of the liquid crystal layer in contact with the liquid crystal layer. In the step of forming the axially symmetric alignment fixed layer, it is important that the liquid layer molecules are tilted at a certain angle (tilt angle) with respect to the normal direction of the substrate. A voltage may be applied to tilt the liquid crystal molecules at an angle with respect to the normal line direction of the substrate. The applied voltage is 1/2 Vth at which the axially symmetric orientation is stabilized in the display mode described above.
Thus, it may be Vst or less. The applied voltage at the time of forming the above-mentioned axially symmetric orientation-fixed layer also becomes large in the panel when the screen becomes large, and only a voltage of 1/2 Vth or less is applied at the time of formation of the above-mentioned axis-symmetrically oriented fixed layer. When the liquid crystal panel is manufactured without increasing the number of pixels and the orientation is not fixed, the axially symmetric orientation state becomes unstable at the time of display, causing display unevenness, causing roughness, and slowing the rise time. There was a problem.

The present invention has been made to solve the problems of the prior art as described above, and has a liquid crystal region in which liquid crystal molecules are uniformly aligned in each pixel region even in a large screen, An object of the present invention is to provide a high-contrast liquid crystal display device having excellent azimuth and viewing angle characteristics and having no roughness.

[0023]

A liquid crystal display device of the present invention has a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a transparent electrode is formed on the pair of substrates. The liquid crystal layer has at least one picture element region for each picture element, and at least one of liquid crystal display devices in which liquid crystal molecules in the picture element region are oriented in axial symmetry about an axis of axial alignment A convex portion that substantially surrounds the pixel region is formed on the surface of the substrate on the liquid crystal layer side so as to be in contact with the transparent electrode, and the convex portion has a region made of a conductive material. And the conductive region is in contact with the transparent electrode, whereby the above object is achieved.

In the liquid crystal display device of the present invention, the liquid crystal molecules of the liquid crystal layer have a negative dielectric anisotropy, and the liquid crystal molecules are aligned substantially perpendicular to the pair of substrates when no voltage is applied,
When a voltage is applied, the liquid crystal molecules may be oriented in axial symmetry with respect to each of the plurality of picture element regions about the axis of axial symmetry.

In the liquid crystal display device of the present invention, the transparent electrodes formed on at least one of the pair of substrates may have a stripe shape.

In the liquid crystal display device of the present invention, the conductive region of the protrusion may be a single-layer metal thin film or a multi-layer metal thin film.

In the liquid crystal display device of the present invention, the convex portion may include a conductive region and an insulating layer, and the insulating layer may be laminated on the conductive region.

In the liquid crystal display device of the present invention, the convex portion may include a conductive region and an insulating layer, and the insulating layer may be formed so as to cover the conductive region.

In the liquid crystal display device of the present invention, the metal thin film may be composed of aluminum, chromium, nickel, molybdenum, titanium, copper, silver or gold alone, or an alloy of two or more thereof. .

In the liquid crystal display device of the present invention, it is preferable that the width of the convex portion is 5 μm or more and 20 μm or less.

In the liquid crystal display device of the present invention, it is preferable that the height of the convex portion is 20% or more and 80% or less of the liquid crystal layer thickness.

In the liquid crystal display device of the present invention, the film thickness of the transparent electrode is preferably in the range of 700 angstroms or more and 4000 angstroms or less.

In the liquid crystal display device of the present invention, it is preferable that the surface resistivity of the convex portion is within a range of 0.5 ohm / square or more and 2.0 ohm / square or less.

The operation of the present invention will be described below.

In the present invention, the position and size of the picture element region of the liquid crystal layer are defined by the presence of the convex portion that substantially surrounds the picture element region, and the liquid crystal molecules in the liquid crystal region are axisymmetric. Alignment Orients in an axially symmetrical manner around the central axis. At this time, since the conductive area of the convex portion is formed so as to be in contact with the transparent electrode, the conductive area of the convex portion functions as an auxiliary electrode of the transparent electrode, and as a result, the resistance of the electrode is reduced. it can. As a result, the non-uniformity of the operating voltage and the applied voltage during the formation of the axially symmetric alignment fixed layer in the liquid crystal panel is reduced, so that a uniform and stable axially symmetric alignment state can be realized in the liquid crystal panel. Therefore, the display quality of the liquid crystal display device can be improved.

Further, by forming the conductive region of the convex portion with a metal thin film, the convex portion can be accurately formed by inexpensive wet etching.

The conductive area of the convex portion can be formed of a multilayer metal thin film. For example, the transparent electrode is IT
O and the conductive region of the convex portion is aluminum or an aluminum alloy, a metal thin film is further formed on the side of the conductive region in contact with the transparent electrode.
Than the difference between the reduction potential of aluminum and the oxidation potential of aluminum.
By reducing the difference between the reduction potential of TO and the oxidation potential of the metal thin film formed on the side in contact with the transparent electrode, the redox reaction between ITO and aluminum in the development step during the photolithography step of patterning the aluminum thin film. It is possible to prevent the occurrence of so-called electrolytic corrosion reaction, which is caused by corrosion, and it is possible to pattern the conductive region of the convex portion with a positive resist, which enables finer processing and realizes higher definition of the liquid crystal display device. it can. For example, a thin film of molybdenum or an alloy of molybdenum can be used as the metal thin film formed on the side in contact with the transparent electrode.

By forming the convex portion into a multi-layer structure in which an insulating layer is laminated on the conductive region, it is possible to improve the adhesion with the alignment film formed on the convex portion. Further, it is possible to prevent vertical leakage between the convex portion and the transparent electrode formed on the other substrate.

The process can be simplified by using, as the insulating layer, a photoresist used for patterning the conductive region without using a new film after etching and using the photoresist as it is without peeling. .

By covering the upper surface and the side surface of the conductive region of the convex portion with the insulating layer, it is possible to prevent the disorder of the alignment of the liquid crystal molecules due to the lateral electric field generated between the conductive regions of the adjacent convex portions. .

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the basic structure of a liquid crystal display device according to the present invention will be described with reference to FIG.

In this liquid crystal display device, as shown in FIG. 1A, a liquid crystal layer 40 composed of liquid crystal molecules 42 having a negative dielectric anisotropy is sandwiched between a pair of substrates 32 and 34. There is. On the surfaces of the pair of substrates 32 and 34 that are in contact with the liquid crystal layer 40, the transparent electrodes 31 and 33 made of ITO are formed, respectively.
Is formed, and a convex portion 36 made of a conductive material is formed on at least one of the transparent electrodes 31 in contact with the transparent electrode 31. In addition, a vertical alignment layer 38 is formed on it.
a and 38b are formed.

As the material of the convex portion 36, it is preferable to use aluminum, chromium, nickel, molybdenum, titanium, copper, silver or gold alone, or an alloy of two or more of these. The reason is that the volume resistance is smaller than that of ITO.

Further, the width of the convex portion 36 is 5 μm or more and 20 μm or more.
The reason for this is that if the thickness is less than 5 μm, problems such as disconnection are likely to occur, and if the thickness exceeds 20 μm, the aperture ratio is significantly reduced.

Further, the height of the convex portion 36 is set to 20% or more and 80% or less of the thickness of the liquid crystal layer. When the height is smaller than 20%, the axially symmetric orientation is not formed and exceeds 80%. In this case, a short circuit will occur between the upper and lower substrates.

If the thickness of the transparent electrode is within the range of 700 angstroms or more and 4000 angstroms or less, if it is less than 700 angstroms,
This is because the transparent electrode is easily peeled off from the glass substrate, and when it exceeds 4000 Å, the light transmittance is significantly deteriorated.

Further, the surface resistivity of the convex portion is set within the range of 0.5 ohm / □ or more and 2.0 ohm / □ or less,
In order to make it smaller than 0.5 ohm / □, it is necessary to unnecessarily widen the width of the convex portion or increase the height of the convex portion, and the aperture ratio is lowered or the other substrate is Causes vertical leakage between the formed transparent electrode,
This is because if it exceeds 2.0 ohms / square, low resistance cannot be realized.

In the liquid crystal display device having this structure, the convex portion 36 defines the region exhibiting the axially symmetric orientation when the axial centering voltage is applied. Therefore, FIG.
As shown in (c), the liquid crystal molecules 42 are oriented in an axially symmetrical manner within the pixel region defined by the convex portion 36 about the axially symmetrical orientation central axis 44.

Axisymmetric Alignment When no centering voltage is applied, the liquid crystal molecules 42 are aligned in the direction perpendicular to the substrate due to the alignment regulating force of the vertical alignment layer, as shown in FIG. When the picture element region in which the axially symmetric orientation centering voltage is not applied is observed with a polarization microscope in a crossed Nicols state, a dark field is exhibited as shown in FIG. 1B (normally black mode). Axisymmetric alignment When a centering voltage is applied, the liquid crystal molecules 42 having negative dielectric anisotropy have a force to align the long axes of the liquid crystal molecules perpendicularly to the direction of the electric field. ) As shown in (), it is tilted from the direction perpendicular to the substrate (halftone display state). When the picture element region in this state is observed with a crossed Nicols polarization microscope, an extinction pattern is observed in the direction along the polarization axis as shown in FIG.

As described above, the liquid crystal display device having this structure has the convex portion 36 so as to surround the picture element region. The thickness of the liquid crystal layer 40 (cell gap) does not include the convex portion 36.
Liquid crystal domains (continuously aligned regions:
Since it is not possible to define the position or size at which a region where no disclination line is generated) is formed, a random alignment state occurs, resulting in a rough display in halftone display.

By forming the convex portion 36 as in the present invention, the position and size of the liquid crystal region exhibiting the axially symmetrical alignment are defined. Further, the convex portion 36 controls the thickness of the liquid crystal layer 40, and is formed to weaken the interaction of liquid crystal molecules between the pixel regions. The thickness of the liquid layer 40 is such that the thickness (dout) of the liquid crystal layer in the vicinity of the pixel region is smaller than the thickness (din) of the liquid crystal layer (in the opening) in the pixel region (din> d).
out), and 0.2 × din ≦ dout
It is preferable to satisfy the relationship of ≦ 0.8 × din. That is, when 0.2 × din> dout, this convex portion 3
In some cases, the effect of 6 weakening the interaction of liquid crystal molecules between the pixel regions is not sufficient, and it may be difficult to form a single axially symmetric alignment region for each pixel region. Furthermore, dout>
If it is 0.8 din, it may be difficult to inject the liquid crystal material into the liquid crystal cell.

The "picture element" is generally defined as the minimum unit for displaying. As used herein, the term "picture element region" refers to a portion of the display device that corresponds to the "picture element." However, in the case of a picture element having a large aspect ratio (long picture element), a plurality of picture element regions may be formed for one long picture element. The number of picture element regions formed corresponding to picture elements is as long as the axially symmetric orientation can be stably formed.
It is preferably as small as possible.

Here, the axially symmetric orientation means a radial orientation, a concentric orientation (tangential orientation) or the like.

(Embodiment 1) FIG. 2 shows a schematic view of a liquid crystal display device of Embodiment 1. 2A is a sectional view taken along line XX in FIG. 2B, and FIG. 2B is a plan view.

This liquid crystal display device has a pair of glass substrates 2 and 8, and a liquid crystal layer 16 is provided between them. On one (upper side of the figure) glass substrate 2, a transparent electrode 3 made of ITO and a vertical alignment layer 22 are formed with the former side facing the substrate 2. A transparent electrode 10 made of ITO is formed on the other (lower side of the figure) glass substrate 8, and a convex portion 17 made of aluminum is formed on the transparent electrode 10. The convex portion 17 is provided so as to surround the picture element region 15, as shown in FIG. Further, a vertical alignment layer 22 is formed on the outer surfaces of the transparent electrode 10 and the protrusions 17.

Further, a columnar spacer 20 is formed outside the pixel area between the transparent electrodes 10 (see FIG. 2B). The columnar spacer 20 adjusts the distance between the substrates 2 and 8, and is provided so as to reach the substrates 2 and 8. The vertical alignment layer 21 is also formed on the peripheral surface of the columnar spacer 20. There is.

The liquid crystal display device having such a structure is manufactured as follows.

First, a transparent electrode 3 made of ITO and having a thickness of 700 nm is formed on one glass substrate 2, and further,
JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated to form the vertical alignment layer 22.

Next, a transparent electrode 10 made of ITO and having a thickness of 700 nm and a width of 160 μm is formed in a stripe shape on the other glass substrate 8, and a convex portion 17 made of aluminum is further formed on the transparent electrode 10. The protrusions 17 are formed by forming an aluminum thin film with a thickness of 3 μm and removing the portions corresponding to the picture element regions 15 by photolithography and etching so as to leave regions with a width of 10 μm from both ends of the transparent electrode 10. went. Although aluminum is used as the metal thin film here, the present invention is not limited to this, and chromium, nickel, molybdenum, titanium, copper, silver or gold alone may be used, or aluminum, chromium, nickel, Molybdenum, titanium,
Two or more alloys of copper, silver or gold may be used.

Next, outside the picture element region between the transparent electrodes 10 and 10, a photosensitive polyimide is used to make a height of about 5 μm.
m columnar spacers 20 were formed.

Next, JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated on the glass substrate 8 on which the transparent electrode 10 and the convex portion 17 were formed to form the vertical alignment layer 21.

Next, both substrates 2 and 8 are bonded together, and an n-type liquid crystal material (Δε = −4.0, Δn = 0.08, cell gap) is formed as a liquid crystal layer 16 between both substrates 2 and 8. 5
A twist angle peculiar to the liquid crystal material was set so that the twist would be 90 ° in μm), and the liquid crystal cell was completed. In the completed liquid crystal cell, the surface resistivity of the transparent electrode 10 and the convex portion 17 as a two-layer structure electrode was 1.2 ohm / □.

Next, polarizing plates were arranged on both sides of the liquid crystal cell so as to be in a crossed Nicols state, and a liquid crystal display device was completed.

FIG. 3 is a diagram showing a result of observing each picture element in a transmission mode using a polarization microscope (Cross Nicol) while applying a voltage of about 4 V to the liquid crystal cell.

As can be seen from FIG. 3, during white display, the liquid crystal molecules in each picture element region are oriented in axial symmetry about the central axis of the alignment, over the entire liquid crystal panel.
Further, it was observed that the central axis of the axisymmetric orientation was formed at the substantially central position of the picture element region, and it was possible to obtain a liquid crystal display device having excellent viewing angle characteristics with no roughness or display unevenness.

(Second Embodiment) In the second embodiment, the convex portion 1
A liquid crystal display device is formed in the same manner as in Embodiment 1 except that 7 is formed of a multilayer metal thin film.

First, a transparent electrode 3 made of ITO and having a thickness of 700 nm is formed on one glass substrate 2, and then J
ALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated to form the vertical alignment layer 22.

Next, a transparent electrode 10 made of ITO and having a thickness of 700 nm and a width of 160 μm is formed in a stripe shape on the other glass substrate 8, and the convex portion 17 composed of two layers of molybdenum and aluminum is further formed on the transparent electrode 10. To form. The formation of the convex portion 17 was performed as follows. For example, molybdenum is formed to a thickness of about 100 nm by vapor deposition, aluminum is formed to a thickness of about 3 μm, and a positive photoresist (TFRB-3; manufactured by Tokyo Ohka Co., Ltd.) is applied to a thickness of about 1 μm. develop. At this time, the presence of the molybdenum thin film between the aluminum thin film and the ITO (transparent electrode 10) can prevent the occurrence of pinholes in the ITO during development. continue,
At the same time, the aluminum thin film and the molybdenum thin film are removed by etching so as to leave a region having a width of 10 μm from both ends of the transparent electrode 10 by etching, and the photoresist 17 is peeled off to form the convex portion 17. Formed. Although aluminum and molybdenum are used here as the metal thin film, the present invention is not limited to this, and a simple substance of chromium, nickel, titanium, copper, silver, or gold may be used, or each of the metal thin films of multiple layers may be used. You may use the alloy of 2 or more types of aluminum, chromium, nickel, molybdenum, titanium, copper, silver, or gold for this layer.

Next, outside the picture element region between the transparent electrodes 10 and 10, a photosensitive polyimide is used to make a height of about 5 μm.
m columnar spacers 20 were formed.

Next, JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated on the glass substrate 8 on which the transparent electrode 10 and the convex portion 17 were formed, to form the vertical alignment layer 21.

Next, both substrates 2 and 8 were bonded together, and an n-type liquid crystal material (Δε = −4.0, Δn = 0.08, cell gap) was used as the liquid crystal layer 16 between both substrates 2 and 8. 5
A twist angle peculiar to the liquid crystal material was set so that the twist would be 90 ° in μm), and the liquid crystal cell was completed. In the completed liquid crystal cell, the surface resistivity of the transparent electrode 10 and the protrusion 17 as a two-layer structure electrode was 1.5 ohm / □.

Next, polarizing plates were arranged on both sides of the liquid crystal cell so as to be in a crossed Nicol state, and a liquid crystal display device was completed.

While applying a voltage of about 4 V to each of the completed liquid crystal cells, each picture element was observed in a transmission mode using a polarization microscope (Cross Nicol).
At the time of white display, the liquid crystal molecules in each picture element region are aligned in an axially symmetric manner around the axis of axially symmetric orientation, and the axis of axially symmetric orientation is almost equal to that of the pixel area over the entire liquid crystal panel. It was observed that the liquid crystal display device was formed at the center position, and a liquid crystal display device having excellent viewing angle characteristics without graininess or display unevenness could be obtained.

(Third Embodiment) In the third embodiment, the convex portion 1
A liquid crystal display device is formed in the same manner as in Embodiment 1 except that 7 is formed of a multilayer film including a metal thin film and an organic resin layer as an insulating layer.

First, a transparent electrode 3 made of ITO and having a thickness of 700 nm is formed on one glass substrate 2, and then J
ALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated to form the vertical alignment layer 22.

Next, a transparent electrode 10 made of ITO and having a thickness of 700 nm and a width of 160 μm is formed in a stripe shape on the other glass substrate 8, and as shown in FIG. A convex portion 17 having two layers, that is, a region 17a and an insulating layer 17b made of a resist is formed. The formation of the convex portion 17 was performed as follows. For example, aluminum is sputtered to a thickness of about 0.5.
μm thick, and a positive photoresist (TFRB
-3; Tokyo Ohka Co., Ltd.) is applied to a thickness of about 2.5 μm, and then exposed and developed, and then the aluminum thin film is formed so as to leave a region of 20 μm width from both ends of the transparent electrode 10. It was carried out by removing the portion of the aluminum thin film corresponding to 15 by etching. This Embodiment 3
The convex portion 17 has a structure in which the resist 17b is formed on the aluminum thin film 17a in the same area as the convex portion 17. Although aluminum was used as the metal thin film, the present invention is not limited to this, and chromium, nickel, molybdenum, titanium, copper,
A simple substance of silver or gold may be used, or an alloy of two or more of aluminum, chromium, nickel, molybdenum, titanium, copper, silver or gold may be used.

Next, a photosensitive polyimide is used outside the pixel region between the transparent electrodes 10 and about 5 μm in height.
m columnar spacers 20 were formed.

Next, JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated on the glass substrate 8 on which the transparent electrode 10 and the convex portion 17 were formed, to form the vertical alignment layer 21.

Next, both substrates 2 and 8 are bonded together, and an n-type liquid crystal material (Δε = −4.0, Δn = 0.08, cell gap) is formed as a liquid crystal layer 16 between both substrates 2 and 8. 5
A twist angle peculiar to the liquid crystal material was set so that the twist would be 90 ° in μm), and the liquid crystal cell was completed. In the completed liquid crystal cell, the surface resistivity of the transparent electrode 10 and the convex portion 17 as a two-layer structure electrode was 1.4 ohm / □.

Next, polarizing plates were arranged on both sides of the liquid crystal cell so as to be in a crossed Nicols state, and a liquid crystal display device was completed.

While applying a voltage of about 4 V to each of the completed liquid crystal cells, each picture element was observed in a transmission mode using a polarization microscope (Cross Nicol).
At the time of white display, the liquid crystal molecules in each picture element region are aligned in an axially symmetric manner around the axis of axially symmetric orientation, and the axis of axially symmetric orientation is almost equal to that of the pixel area over the entire liquid crystal panel. It was observed that the liquid crystal display device was formed at the center position, and a liquid crystal display device having excellent viewing angle characteristics without graininess or display unevenness could be obtained.

(Embodiment 4) Embodiment 4 is the same as Embodiment 3, except that the convex portion 17 is formed of a multilayer film including a metal thin film and an organic resin layer as an insulating layer. A liquid crystal display device is formed in the same manner as 1. However, in the third embodiment described above, the insulating layer is formed on the metal thin film in the same area as that, but in the fourth embodiment, the insulating layer is formed so as to cover the upper surface and the side surface of the metal thin film. is there.

First, a transparent electrode 3 made of ITO and having a thickness of 700 nm is formed on one glass substrate 2, and then J
ALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated to form the vertical alignment layer 22.

Next, a transparent electrode 10 made of ITO and having a thickness of 700 nm and a width of 160 μm is formed in a stripe shape on the other glass substrate 8, and as shown in FIG. A convex portion 17 having two layers, that is, a region 17a and an insulating layer 17b made of a resist is formed. The formation of the convex portion 17 was performed as follows. For example, aluminum is sputtered to a thickness of approximately 1 μm.
Then, a positive photoresist (TFRB-
3; after applying a thickness of about 2 μm, manufactured by Tokyo Ohka Co., Ltd.,
Expose and develop. Then, the aluminum thin film is removed by etching so as to leave a region having a width of 10 μm from both ends of the transparent electrode 10, and the photoresist is baked at about 120 ° C. to remove the aluminum thin film corresponding to the pixel region 15. The convex portion 17 was formed by softening the photoresist existing only on the aluminum thin film and covering the upper surface and the side surface of the aluminum thin film 17a with the photoresist 17b. Although aluminum is used as the metal thin film, the present invention is not limited to this, and a single substance of chromium, nickel, molybdenum, titanium, copper, silver or gold is used, or aluminum, chromium, nickel, molybdenum, titanium, copper. Two or more alloys of silver, gold or gold may be used.

Next, outside the picture element region between the transparent electrodes 10 and 10, a photosensitive polyimide is used to make a height of about 5 μm.
m columnar spacers 20 were formed.

Next, JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated on the glass substrate 8 on which the transparent electrode 10 and the convex portion 17 were formed to form the vertical alignment layer 21.

Next, both substrates 2 and 8 were bonded together, and an n-type liquid crystal material (Δε = −4.0, Δn = 0.08, cell gap) was formed as a liquid crystal layer 16 between both substrates 2 and 8. 5
A twist angle peculiar to the liquid crystal material was set so that the twist would be 90 ° in μm), and the liquid crystal cell was completed. In the completed liquid crystal cell, the surface resistivity of the transparent electrode 10 and the convex portion 17 as a two-layer structure electrode was 1.6 ohm / □.

Next, polarizing plates were arranged on both sides of the liquid crystal cell so as to be in a crossed Nicols state, and a liquid crystal display device was completed.

While applying a voltage of about 4 V to each of the completed liquid crystal cells, each picture element was observed in a transmission mode using a polarizing microscope (Cross Nicol).
At the time of white display, the liquid crystal molecules in each picture element region are aligned in an axially symmetric manner around the axis of axially symmetric orientation, and the axis of axially symmetric orientation is almost equal to that of the pixel area over the entire liquid crystal panel. It was observed that the liquid crystal display device was formed at the center position, and a liquid crystal display device having excellent viewing angle characteristics without graininess or display unevenness could be obtained.

In the above-described Embodiments 2 to 4, the metal thin film has two layers, or the metal thin film and the organic resin layer (for example, resist) have two layers, but the present invention is not limited to this. Needless to say, a multilayer structure having three or more layers, which has more than two layers with the same material configuration, may be used. In addition, this is similar to Embodiment 2 described later in Embodiment 2
The same applies when the fourth embodiment is applied.

(Fifth Embodiment) The fifth embodiment is applied to a plasma addressed liquid crystal display device.

FIG. 6 is a schematic sectional view showing a specific structure of the plasma addressed liquid crystal display device according to the present embodiment.

In this liquid crystal display device, a substrate 58 made of transparent glass or the like is provided on one side (upper side in the drawing) with the liquid crystal layer 59 interposed therebetween.
And a plasma generating substrate 52 having a thin glass plate 53 as a dielectric sheet and a substrate 54 arranged opposite to each other on the other side (lower side in the drawing). A partition 57 is formed in a line shape between the substrate 54 of the plasma substrate 52 and the thin glass 53, and a space surrounded by the partition 57, the substrate 54, and the thin glass 53 is filled with an ionizing gas. To form a line-shaped channel 55. Inside each channel 55, an anode electrode A and a cathode electrode K for ionizing the ionizing gas are provided.

On the other hand, a color filter 63 is provided on the liquid crystal layer 59 side of the substrate 58, and a transparent electrode 60 as a data line is provided on the color filter 63 in a striped and linear channel 55. Are crossed, and are wired in the vertical direction, for example. The liquid crystal layer 59 is sandwiched between the substrate 58 and the thin glass plate 53, and the cell thickness between the substrate 58 and the thin glass plate 53 is kept constant by the columnar spacer 67. The substrate 58 and the thin glass plate 53
A vertical alignment film 68 is formed on the surface of the liquid crystal layer 59 side. Further, the display cell 51 is composed of a portion including the substrate 58, the color filter 63, the transparent electrode 60, and the liquid crystal layer 59.

A polarizing plate 69a is provided on one side (upper side in the drawing) of the liquid crystal display device thus configured, and a polarizing plate 69b and a backlight 62 are provided on the other side (lower side in the drawing).

In the method of manufacturing the plasma addressed liquid crystal display device, the plasma generating substrate 52 shown in FIG. 6 is used instead of the glass substrate 8 shown in FIG. The plasma generation substrate 52 is manufactured by a known method.

FIG. 7 shows a detailed schematic view of the display cell 51 portion of the plasma addressed liquid crystal display device of the second embodiment. FIG. 7A is a sectional view taken along line XX of FIG.
FIG. 7B shows a plan view.

On the thin glass plate 53 on the lower side of the figure, JALS-
The vertical alignment layer 68 was formed by spin coating 204 (manufactured by Japan Synthetic Rubber Co., Ltd.).

A color filter 63 is formed on the glass substrate 58 on the upper side of the drawing, and a thickness 7 made of ITO is formed on the color filter 63.
A transparent electrode 60 having a width of 00 nm and a width of 160 μm is formed in a stripe shape, and a convex portion 70 made of aluminum is formed on the transparent electrode 60. The convex portion 70 is formed by forming an aluminum thin film with a thickness of 3 μm and removing the portion corresponding to the picture element region 71 by photolithography and etching so as to leave a region with a width of 10 nm from both ends of the transparent electrode 60. went. Further, a columnar spacer 67 having a height of about 5 μm was formed outside the pixel region between the transparent electrodes 60 by using photosensitive polyimide. Further, on the glass substrate 58 on which the transparent electrode 60 and the convex portion 70 are formed, JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.)
Was spin-coated to form a vertical alignment layer 68. Also in this embodiment, not only aluminum but also the above metal simple substance or alloy can be used.

Then, the thin glass plate 53 on the plasma generating substrate 52 side and the glass substrate 58 on the display cell 51 side are bonded together, and an n-type liquid crystal material is formed as a liquid crystal layer 59 between the thin glass plate 53 and the glass substrate 58. (Δε = −4.0,
A twist angle peculiar to the liquid crystal material was set so that the twist was 90 ° at Δn = 0.08 and the cell gap was 5 μm. The surface resistivity of the transparent electrode 60 and the convex portion 70 as a two-layer structure electrode was 1.2 ohm / □.

After that, polarizing plates 69a and 69b are arranged on both sides of the plasma generation substrate 52 and the display cell 51 bonded together so as to be in a crossed Nicol state as shown in FIG. Backlight 6 on the outside
2 was provided to complete the plasma addressed liquid crystal display device.

When the plasma-addressed liquid crystal display device was brought into a display state and each picture element was observed in a transmission mode using a polarization microscope (Cross Nicol), the same result as in FIG. 3 was obtained.

As can be understood from this, during white display, the liquid crystal molecules in each pixel region are oriented in axial symmetry around the central axis of axial alignment, over the entire panel,
Moreover, it was observed that the axially symmetrical alignment central axis was formed substantially at the central position of the pixel region, and it was possible to obtain a plasma addressed liquid crystal display device with excellent viewing angle characteristics without graininess or display unevenness. It was

(Comparative Example 1) FIG. 9 is a sectional view of a liquid crystal display device used in a conventional example.

This liquid crystal display device is manufactured as follows. That is, a transparent electrode 104 made of ITO and having a thickness of 700 nm was formed on one glass substrate 102, and JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated to form a vertical alignment layer 105.

A transparent electrode 103 made of ITO and having a thickness of 700 nm is formed on the other glass substrate 101, and a photosensitive polyimide is used outside the pixel region on the transparent electrode 103 to form a spacer having a height of about 5 μm. Formed 107. After that, with acrylic negative resist, height about 3μ
The convex portion 106 of m was formed. The area surrounded by the convex portion 106, that is, the size of the pixel area is 190 μm × 325.
μm. Then, JALS-204 (manufactured by Japan Synthetic Rubber Co., Ltd.) was spin-coated to form a vertical alignment layer 105.

After that, both substrates are bonded together, and an n-type liquid crystal material (Δε =
-4.0, Δn = 0.08, 90 at cell gap 5 μm
The liquid crystal cell was completed by injecting (twist angle peculiar to the liquid crystal material was set so as to be twisted). The surface resistivity of the transparent electrode 103 was 6.0 ohm / □.

After that, polarizing plates were arranged on both sides of the liquid crystal cell so as to be in a crossed Nicols state, and a liquid crystal display device was completed.

FIG. 8 shows the result of observing each picture element in the transmission mode using a polarization microscope (Cross Nicol) while applying a voltage of about 4 V to the completed liquid crystal cell.

As can be understood from FIG. 8, the liquid crystal molecules in each picture element region are oriented in axial symmetry about the central axis during white display, but depending on the picture element region, they are oriented in axial symmetry. It was observed that the central axis was formed at a position largely deviated from the center of the picture element region, and it was not possible to obtain a liquid crystal display device having excellent viewing angle characteristics free from roughness and display unevenness.

The fifth embodiment described above has a configuration in which the first embodiment is applied to the plasma addressed liquid crystal display device, but the present invention is not limited to this, and the second embodiment described above is applied to the plasma addressed liquid crystal display device. ~ Embodiment 4 can be applied. Even in that case, in the obtained plasma addressed liquid crystal display device, the liquid crystal molecules in each picture element region are oriented in axial symmetry about the axis of axial symmetry and are axially symmetric as in the fifth embodiment. It is observed that the uniform alignment central axis is formed substantially at the central position of the picture element region, and it is of course that the viewing angle characteristic is excellent without graininess or display unevenness.

[0112]

As described in detail above, in the present invention, the position and size of the picture element region of the liquid crystal layer are defined by the presence of the convex portion that substantially surrounds the picture element region, The liquid crystal molecules in the elementary regions are oriented in axial symmetry about the central axis of the alignment, and at this time, the conductive region of the convex portion is formed so as to be in contact with the transparent electrode. Region functions as an auxiliary electrode of the transparent electrode, and as a result, the resistance of the electrode can be reduced, which results in non-uniformity of the operating voltage and the applied voltage during the formation of the axisymmetric alignment fixed layer in the liquid crystal panel. Is smaller, it is possible to realize a uniform and stable axisymmetric alignment state in the liquid crystal panel, and it is possible to improve the display quality of the liquid crystal display device.

Further, by forming the conductive region of the convex portion with a metal thin film, the convex portion can be formed with high precision by inexpensive wet etching. Further, when the conductive area of the convex portion is formed of a multi-layered metal thin film, it is possible to prevent the occurrence of electrolytic corrosion reaction, and it is possible to pattern the conductive area of the convex portion with a positive resist. Processing becomes possible and high definition of the liquid crystal display device can be realized.

When the convex portion has a multi-layer structure in which an insulating layer is laminated on the conductive region, the adhesion with the alignment film formed on the convex portion can be improved, and the convex portion and the It is possible to prevent vertical leakage from the transparent electrode formed on the other substrate. Further, the process can be simplified by using the photoresist used for patterning the conductive region as it is, without forming a new film as the insulating layer, after etching and without peeling it off. In addition, when the upper surface and the side surface of the conductive region of the convex portion are covered with the insulating layer, it is possible to prevent the alignment disorder of the liquid crystal molecules due to the horizontal electric field generated between the conductive regions of the adjacent convex portions.

Further, according to the present invention, there is provided a high-contrast liquid crystal display device in which liquid crystal molecules in each picture element region are oriented in axial symmetry and which has excellent viewing angle characteristics. The obtained liquid crystal display device of the present invention is particularly preferably used for a large-sized liquid crystal display device suitable for application to a high-definition television such as HDTV or a display for CAD.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a basic configuration of a liquid crystal display device according to the present invention, where (a) and (b) are (c) and (d) when no axial centering alignment centering voltage is applied. ) Indicates a state when an axially symmetrical orientation centering centering voltage is applied, (a) and (c) are cross-sectional views, and (b) and (d) show the results of observing the upper surface with a crossed Nicol polarization microscope. .

2A and 2B are diagrams showing a liquid crystal display device according to Embodiment 1 of the present invention, in which FIG. 2A is a sectional view and FIG. 2B is a plan view.

FIG. 3 is a diagram for explaining a relationship between a position of an axially symmetrical alignment central axis and display quality in the first and second embodiments of the present invention.

FIG. 4 is a sectional view showing a structure of a convex portion according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a structure of a convex portion according to Embodiment 4 of the present invention.

FIG. 6 is a sectional view showing a plasma addressed liquid crystal display device according to a second embodiment of the present invention.

7A and 7B are views showing a display cell portion of a plasma addressed liquid crystal display device according to a second embodiment of the present invention, wherein FIG. 7A is a sectional view and FIG. 7B is a plan view.

FIG. 8 is a diagram for explaining the relationship between the position of the central axis of the axially symmetrical alignment and the display quality in the comparative example.

9A and 9B are views showing a conventional liquid crystal display device, in which FIG. 9A is a sectional view and FIG. 9B is a plan view.

FIG. 10 is a diagram for explaining the configuration and operation principle of another conventional liquid crystal display device, wherein (a) and (b) are (c) and (d) when no axial centering alignment centering voltage is applied. ) Indicates a state when an axially symmetrical orientation centering centering voltage is applied, (a) and (c) are cross-sectional views, and (b) and (d) show the results of observing the upper surface with a crossed Nicol polarization microscope. .

FIG. 11 is a diagram showing a voltage transmittance curve of a liquid crystal display device.

[Explanation of symbols]

2 glass substrates 3 transparent electrodes 8 glass substrates 10 Transparent electrode 15 picture element area 16 Liquid crystal layer 17 convex 17a conductive region 17b Insulation layer 20 Column spacer 21 Vertical alignment layer 22 Vertical alignment layer 31 transparent electrode 32 substrates 33 Transparent electrode 34 substrate 36 convex 38a, 38b Vertical alignment layer 40 Liquid crystal layer 42 Liquid crystal molecule 44 Axisymmetric orientation central axis 51 display cells 52 Plasma generation substrate 53 Thin glass 54 substrate 55 channels 57 partitions 58 substrate 59 Liquid crystal layer 60 transparent electrode A anode electrode K cathode electrode 62 Backlight 63 color filters 67 Column spacer 68 Vertical alignment layer 69a, 69b Polarizing plate 70 convex 71 Picture element area

Front page continued (72) Inventor Noriaki Nakamura 22-22 Nagaike-cho, Naganocho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Inventor Katsuyuki Himejima 22-22, Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture (56) ) Reference JP-A-2-228629 (JP, A) JP-A-9-258241 (JP, A) JP-A-4-86726 (JP, A) JP-A-10-186330 (JP, A) JP-A-10-186330 (JP, A) 7-120728 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1333 G02F 1/1337 G02F 1/1343

Claims (10)

(57) [Claims] 1. A pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, a transparent electrode is formed on the pair of substrates, and the liquid crystal layer has at least one picture element for each picture element. In a liquid crystal display device having a pixel region, in which liquid crystal molecules in the pixel region are oriented in axial symmetry around an axis of axial alignment, the transparent electrode is formed on the surface of at least one substrate on the liquid crystal layer side. A convex portion that substantially surrounds the picture element region, and the convex portion has a region made of a conductive material, and the conductive region is It is in contact with the transparent electrode, and the height of the protrusion is 20% of the liquid crystal layer thickness.
A liquid crystal display device characterized by being 80% or less . 2. The liquid crystal molecules of the liquid crystal layer have a negative dielectric anisotropy, the liquid crystal molecules are aligned substantially perpendicular to the pair of substrates when no voltage is applied, and the liquid crystal molecules are aligned when a voltage is applied. The liquid crystal display device according to claim 1, wherein the plurality of picture element regions are oriented symmetrically with respect to an axially central alignment center axis. 3. The liquid crystal display device according to claim 1, wherein the transparent electrode formed on at least one of the pair of substrates has a stripe shape. 4. The liquid crystal display device according to claim 1, wherein the conductive region of the convex portion is a single-layer metal thin film or a multi-layer metal thin film. 5. The liquid crystal according to claim 1, wherein the convex portion comprises a conductive region and an insulating layer, and the insulating layer is laminated on the conductive region. Display device. 6. The structure according to claim 1, wherein the convex portion includes a conductive region and an insulating layer, and the insulating layer is formed so as to cover the conductive region. Liquid crystal display device. 7. The liquid crystal according to claim 4, wherein the metal thin film is made of aluminum, chromium, nickel, molybdenum, titanium, copper, silver or gold, or an alloy of two or more of these. Display device. 8. The liquid crystal display device according to claim 1, wherein the width of the convex portion is 5 μm or more and 20 μm or less. 9. The liquid crystal display device according to claim 1, wherein the film thickness of the transparent electrode is in the range of 700 angstroms or more and 4000 angstroms or less. 10. The surface resistivity of the convex portion is 0.5 ohm /
5. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is in the range of □ or more and 2.0 Ω / □ or less.