KR19990070436A - Liquid crystal display with a new electrode structure - Google Patents

Abstract

A common electrode is formed over the entire surface of the upper substrate of the liquid crystal display device having different electrode arrangements, and a linear pixel electrode is formed on the lower substrate. When a voltage is applied to the two electrodes to give a potential difference between the two electrodes, an electric field symmetrical with respect to the longitudinal center line on the pixel electrode and the longitudinal center line of the region between the pixel electrodes is formed. The electric field lines have vertical and horizontal components in the region between the pixel electrode and the pixel electrode, and the liquid crystal molecules are rearranged by the electric field with the twist angle and the tilt angle. Due to the rearrangement of the liquid crystal molecules, the polarization of the incident light changes, thereby enabling the display operation.

Description

Liquid crystal display with a new electrode structure

The present invention relates to a liquid crystal display device having a novel electrode structure and a manufacturing method thereof.

In general, a liquid crystal display device has electrodes on both substrates or an inner surface of one substrate, and is an optical switching medium having a liquid crystal material layer between two electrodes. When a potential difference is applied to both electrodes, liquid crystal molecules are re-used due to the potential difference. Arranged and rearranged liquid crystal molecules display an image by scattering light or changing light transmission properties.

As an example of a conventional liquid crystal display device, a nematic liquid crystal material is inserted between upper and lower electrodes formed on the inner surfaces of two lower and upper substrates, respectively, and the liquid crystal molecules are twisted and oriented parallel to the substrate. And a twisted nematic liquid crystal display disclosed in Patent No. 5,576,861. In this liquid crystal display, when a voltage is applied to the upper and lower electrodes to give a potential difference, an electric field perpendicular to both substrates is formed, and a torque for arranging the long axis direction of the liquid crystal molecules in parallel with the direction of the electric field (the magnitude of this torque is Depending on the strength of the electric field), ie, torque and rubbing due to the dielectric anisotropy, and the liquid crystal molecules are rearranged so as to balance the elastic torque for arranging the long axis direction of the liquid crystal molecules in a specific direction.

Another example of a conventional liquid crystal display device is disclosed in US Pat. No. 5,598,285, in which two rows of electrodes are arranged in parallel on one substrate with a liquid crystal material layer between them, and the liquid crystal molecules are oriented parallel to the substrate. And a liquid crystal display device. In this liquid crystal display device, an electric potential is applied between electrodes to form an electric field essentially parallel to the substrate and perpendicular to the two electrodes, and the liquid crystal is balanced so that the torque due to the dielectric anisotropy of the liquid crystal material and the elastic torque due to the alignment treatment are balanced. The molecules rearrange.

Each of these conventional liquid crystal display devices has a problem.

The biggest problem of the twisted nematic liquid crystal display is that the viewing angle is narrow. In this liquid crystal display device, as the angle between the direction of the eye of the person viewing the display device and the direction perpendicular to the surface of the display device increases, the birefringence (Δn), which is a difference in refractive index between the long axis direction and the short axis direction of the liquid crystal molecules, The product of the thickness d of the liquid crystal layer, that is, the value of Δn · d, becomes large, and accordingly, the contrast (a value obtained by dividing the brightness of the brightest state by the brightness of the darkest state) is rapidly reduced. In addition, there is a phenomenon of gray level inversion in which brightness is reversed. Therefore, the viewing angle (the angle at which the contrast is maintained at 10 is called a viewing angle) is very narrow, and the image quality deteriorates sharply compared to the image viewed from the front when the display device is viewed at an angle larger than the viewing angle.

In order to compensate the viewing angle, as described in the above-mentioned US Patent No. 5,576,861, a method of widening the viewing angle using a phase difference compensation plate or the like has been proposed, but since an additional process of attaching an additional compensation plate is required. In addition to higher costs and increased processing, the use of compensation plates still limits the viewing angle.

In the second device, the electric field located in the region between the two electrodes becomes smaller as it moves away from the two electrodes, so that the minimum voltage (threshold voltage) for passing light in the normally black mode is not only high. Since the voltage (saturation voltage) that passes the light as much as possible is high, there is a problem in that the power consumption is large. In addition, not only all the electrodes are formed on one substrate, but in order to ensure sufficient capacitance, the pixel electrode and the common electrode must have an overlapping portion with an insulating layer therebetween, so that the aperture ratio through which light passes is small. In addition, since all electrodes are formed on one substrate and no electrodes are formed on the other substrate, there is a problem in that image quality is deteriorated when static electricity occurs on the substrate on which the electrode is not formed.

One object of the present invention is to ensure a wide viewing angle.

Another object of the present invention is to increase the transmittance.

Another object of the present invention is to prevent the degradation of the image quality due to static electricity.

1 is a plan view illustrating one pixel of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II 'of FIG. 1 and shows the upper and lower substrates together.

3 illustrates an equipotential surface of an electric field formed when a voltage is applied to a liquid crystal display according to an exemplary embodiment of the present invention.

4 is a plan view illustrating a change in twist angle in the liquid crystal display according to the exemplary embodiment of the present invention;

5 is a graph illustrating a change in transmittance according to a position in a liquid crystal display according to an exemplary embodiment of the present invention.

6 to 8 are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to an exemplary embodiment of the present invention.

In order to solve the above problems, the present invention updates the arrangement of the electrodes.

That is, a first electrode is formed over the entire surface on one substrate, and a linear second electrode is formed on the other substrate.

In general, the first electrode is a common electrode for applying a common voltage to all pixels, and is made of a transparent conductive material. The second electrode is a pixel electrode for applying a different image signal to each pixel.

In such a liquid crystal display, when a voltage is applied to the first electrode and the second electrode to give a potential difference between the two electrodes, an electric field symmetrical with respect to the longitudinal center line of the second electrode and the longitudinal center line of the region between the second electrodes is formed. This electric field has vertical and horizontal components on the second electrode and between the second electrode, and the liquid crystal molecules are rearranged by the electric field with the twist angle and the tilt angle.

As such, the liquid crystal molecules rearrange and have both a twist angle and an inclination angle, thereby widening the viewing angle.

An alignment layer may be formed on the substrate on which the first electrode and the second electrode are formed to align the liquid crystal molecules horizontally with respect to the substrate, and the alignment layer may be rubbed in a predetermined direction. It is preferable that the rubbing direction of the alignment layer has a constant angle with respect to the direction of the second electrode and the direction perpendicular to the second electrode.

In addition, the polarizers are attached to the outside of the two substrates, respectively, and the transmission axes of the polarizers are preferably perpendicular to each other. And the transmission axis of a polarizing plate should be parallel to the rubbing direction of an adjacent alignment film.

It is preferable that the space | interval between the linear 2nd electrodes shall be 20 micrometers or less, and by doing so, a transmittance | permeability can be raised.

Such a liquid crystal display device can be manufactured by a simple process using four masks. First, a gate wiring is formed of a metal, a gate insulating film is laminated, and an amorphous silicon layer and a doped amorphous silicon layer are successively stacked and then patterned together. After the metal is deposited and patterned to form the data line and the pixel electrode, the doped amorphous silicon layer exposed using the source electrode and the drain electrode as a mask is etched. Finally, a protective film is formed.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings so that a person skilled in the art may easily implement the present invention.

First, a first embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a plan view illustrating one pixel of a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1 to show both the upper substrate and the lower substrate. It is.

First, the structure of the lower substrate in which an electrode is formed is demonstrated.

A gate line 20 for transmitting a scan signal in a horizontal direction is formed on an inner surface of the lower substrate 10 made of a transparent insulating material such as glass or quartz, and part of the gate line 20 becomes a gate electrode 2. On the gate line 20, a gate insulating film 3 made of silicon nitride or the like is formed over the entire surface of the substrate 10. A semiconductor layer 4 made of amorphous silicon or the like is formed on the gate insulating film 3 on the gate electrode 2, and the semiconductor layer 4 is used as a ohmic contact layer on both sides of the gate electrode 2. Doped amorphous silicon layers 51 and 52 are formed. A source electrode 6 and a drain electrode 7 are formed on the doped amorphous silicon layers 51 and 52, respectively, and the source electrode 6 intersects the gate line 20 in the vertical direction and receives an image signal from the outside. It is connected to the data line 60 to transmit. The drain electrode 7 is formed long in the vertical direction and is connected to a plurality of pixel electrodes 8 connected to each other.

Here, the gate electrode 2, the source electrode 6, the drain electrode 7, the gate insulating film 3, the ohmic contact layers 51 and 52, and the amorphous silicon layer 4 form a thin film transistor, and the source electrode ( The amorphous silicon layer 4 between 6) and the drain electrode 7 becomes a channel portion of the thin film transistor. That is, when a scan signal is applied to the gate electrode 2 through the gate line 20, the thin film transistor is turned on and thus an image signal applied to the source electrode 6 through the data line 60. Is passed through the amorphous silicon layer 4 to the drain electrode 7, and a signal is applied to the pixel electrode 8 through the drain electrode 7.

A protective film 9 made of silicon nitride or the like is covered on the entire surface of the substrate 10 on which the source and drain electrodes 6 and 7, the data line 60, and the pixel electrode 8 are formed, on which a polyimide ( An alignment film 30 made of a material such as polyimide is applied. On the other hand, a polarizing plate 40 is attached to the outer surface of the lower substrate 10.

A common electrode 12 made of a transparent conductive material such as indium tin oxide (ITO) is formed over the entire surface of the substrate 11 on the inner surface of the substrate 11 made of a transparent insulating material such as glass or quartz. An alignment film 31 made of polyimide or the like is formed, and a polarizing plate 41 is attached to an outer surface thereof.

Finally, a liquid crystal material layer having optical anisotropy is inserted between the two substrates 10 and 11.

Next, the general shape of the electric field of the liquid crystal display will be described in detail with reference to FIG. 3.

A voltage is applied to the pixel electrode 8 and the common electrode 12 formed on the lower substrate 10 and the upper substrate 11, respectively, to give a potential difference between the two electrodes 8 and 12, as shown in FIG. An electric field with the same equipotential surface is created. 3 shows a case where the width of the pixel electrode 8 formed on the lower substrate 10 is 8 μm and the interval between the two pixel electrodes 8 is 24 μm and 17 μm, respectively.

As can be seen in FIG. 3, the shape of the electric field is at the center line C (actually corresponding to the face) of the pixel electrode 8 and the center line B (actually corresponding to the face) of the region between the pixel electrode 8. It is symmetrical about. The shape of the equipotential surface is essentially formed in a semi-ellipse or parabolic shape with its apex at the center line B of the region between the pixel electrode 8 and the center line C of the pixel electrode 8. In a portion close to the common electrode 12 above, the direction becomes substantially parallel to the upper substrate 11.

Then, the state in which the liquid crystal molecules are rearranged by the electric field is divided into components that are horizontal to the substrate and components that are perpendicular thereto.

First, the initial state will be described.

The alignment layers 30 and 31 formed inside the two substrates 10 and 11 are aligned by rubbing or ultraviolet irradiation, so that the liquid crystal molecules are all aligned in one direction, but have a slight diameter with respect to the substrates 10 and 11. It has a square but becomes substantially horizontal, and is arranged to have a predetermined angle with respect to the direction of the pixel electrode 8 and the direction perpendicular thereto when viewed from a plane parallel to the substrates 10 and 11. The transmission axes of the polarizing plates 40 and 41 are arranged to be perpendicular to each other, and the transmission axes of the lower polarizing plate 40 substantially coincide with the rubbing direction. The liquid crystal material contained between the two alignment layers 30 and 31 is a nematic liquid crystal having a positive dielectric anisotropy.

Next, a voltage is applied to the pixel electrode 8 and the common electrode 12, respectively. At this time, the arrangement of the liquid crystal molecules is determined by equilibrium between the force due to the electric field (depending on the direction and intensity of the electric field) and the elastic restoring force generated by the alignment process.

The rearrangement state of the liquid crystal molecules is divided into components parallel to the substrate and perpendicular to the substrate. For convenience of description, the direction perpendicular to the substrates 10 and 11 is z-axis, and the direction perpendicular to the substrates 10 and 11 and perpendicular to the longitudinal direction of the pixel electrode 8 is the x-axis, and the longitudinal direction of the pixel electrode 8. Let's set the direction parallel to the y axis. That is, the direction from left to right in FIG. 3 is the x-axis, the direction from the bottom of the paper to the ground along the length direction of the pixel electrode 8 is the y-axis, and the direction from the lower substrate 10 to the upper substrate 11. Is taken as the z axis.

First, a change in the angle at which the long axis of the liquid crystal molecules is parallel to the substrate, that is, on the xy plane with respect to the torsion angle of the liquid crystal molecules, that is, the x axis or the initial arrangement direction, will be described with reference to FIG. 3.

As shown in Figure 3, the rubbing direction is a vector Xy plane component of the electric field is a vector The angle between the major axis of the liquid crystal molecules and the x axis is represented by ψ _LC .

Xy plane component of the electric field ( Direction is the x direction, and the intensity of the electric field component is almost zero above the pixel electrode 8 in the x direction, and becomes the maximum at the boundary of the pixel electrode 8, It becomes smaller toward the center line B and becomes the minimum at the center line B of the area between the pixel electrodes 8.

The magnitude of the elastic restoring force by the orientation treatment is constant regardless of the position on the xy plane.

Since the liquid crystal molecules should be arranged so that these two forces are in equilibrium, the direction of the long axis of the liquid crystal molecules is determined by the electric field component ( ), While being substantially parallel to each other and having a large angle with respect to the rubbing direction, the long axis of the liquid crystal molecules toward the centerline of the region between the pixel electrodes is the xy plane component of the electric field ( The angle? _LC formed with respect to the direction of?) Becomes large, and the major axis and the rubbing direction of the liquid crystal molecules become the same in the center line B of the region between the pixel electrodes 8.

On the other hand, the xy plane component of the electric field ( ) Decreases from the lower alignment layer 30 toward the upper alignment layer 31 in the z direction, and the elastic restoring force due to the alignment is the largest on the surfaces of the alignment layers 30 and 31, and the liquid crystal layer between the two alignment layers 30 and 31. It gets smaller toward the center of.

Looking at the torsion angle from the lower alignment layer 30 to the upper alignment layer 31, that is, along the z axis and the long axis direction of the liquid crystal molecules forming the x axis, the torsion angle is the force due to the alignment force on the surfaces of the alignment layers 30 and 31. Because of its strength, it is large, becomes smaller toward the center of the liquid crystal layer, and becomes closer to the direction of the electric field. Immediately above the alignment films 30 and 31, the long axes of the liquid crystal molecules are arranged in the same direction as the rubbing direction.

Next, the change of the inclination angle of the liquid crystal molecules, that is, the angle between the long axis of the liquid crystal molecules and the z axis perpendicular to the substrate will be described.

In the initial state where no voltage is applied, the long axis of the liquid crystal molecules has a slight pretilt angle near the two alignment layers 30 and 31, but is essentially arranged in a direction parallel to the substrate. That is, the angle between the major axis of the liquid crystal molecules and the z axis is 90 degrees.

Referring first to the area above the pixel electrode 8, the direction of the electric field in this portion is approximately in the z-axis direction, and the intensity of the electric field is substantially constant between the two alignment films 30 and 31. As described above, the magnitude of the elastic restoring force by the alignment treatment is the largest on the surfaces of the two alignment layers 30 and 31 and decreases toward the center of the liquid crystal layer. The liquid crystal molecules must be arranged such that these two forces are in equilibrium. Therefore, the liquid crystal molecules are arranged in parallel with the substrate because the alignment force is strong on the surfaces of the two substrates 10 and 11, but since the electric field of this portion is mostly in the z direction and its magnitude is large, the inclination angle is drastically reduced to the center of the liquid crystal layer In, the long axis of the liquid crystal molecules is arranged in a direction substantially parallel to the z axis.

Next, the arrangement of the liquid crystal molecules in the centerline B of the region between the pixel electrodes 8 will be described. There is no z-direction component of the electric field in this region. Accordingly, there is no change in the inclination angle of the liquid crystal molecules, and the liquid crystal molecules maintain the initial arrangement.

Finally, the arrangement of the liquid crystal molecules in the region from the boundary portion of the pixel electrode 8 to the center line B of the region between the pixel electrodes 8 will be described.

In the boundary portion of the pixel electrode 8, the direction of the electric field is formed in a direction having a constant angle with respect to the z-axis and the x-axis so as to have vertical and horizontal components. The vertical component of this electric field is basically similar to the region above the pixel electrode 8 so that its intensity is constant. Accordingly, the inclination angle of the liquid crystal molecules is also changed in a similar manner and arranged almost parallel to the substrate on the surface of the substrate, and the inclination angle of the liquid crystal molecules decreases gradually away from the substrate toward the center of the liquid crystal layer. At this time, the smallest inclination angle of the liquid crystal molecules is the centerline portion of the two substrates.

However, the region in which the electric field has both horizontal and vertical components is formed very narrowly, and if the electric field is out of the boundary of the pixel electrode 8, the shape of the electric field is rapidly changed in the x-axis direction. That is, in the region between the center plane B of the region between the pixel electrode 8 and the pixel electrode 8, there is almost no z-axis component of the electric field. Therefore, the liquid crystal molecules in this region maintain the parallel angle with respect to the substrate.

As such, when voltage is applied to the two electrodes 8 and 12, the liquid crystal molecules are rearranged at a torsion angle and an inclination angle, and the transmittance of light is changed due to the change in the torsion angle and the inclination angle.

5 illustrates a graph in which transmittance of a liquid crystal display according to an exemplary embodiment of the present invention is measured. This graph measures the transmittance by changing the distance between the pixel electrodes to 24 µm and 17 µm.

As shown in FIG. 5, the transmittance is highest at the edge portion of the pixel electrode 8, and the transmittance is lowered toward the pixel electrode 8 to be minimized at the centerline B of the region between the pixel electrodes 8 and rises again. . Since the pixel electrode 8 is made of an opaque metal, no light is transmitted through the pixel electrode 8.

However, when the width of the linear pixel electrode and the distance between the pixel electrodes in the liquid crystal display device according to the exemplary embodiment of the present invention are changed, the shape of the electric field is changed and the transmittance is also changed. Thus, it is necessary to optimize the distance between the width of the pixel electrode and the pixel electrode.

As shown in FIG. 4, when the distance between the pixel electrodes 8 is narrowed, the transmittance between the pixel electrodes 8 increases. That is, when the distance between electrodes is 24 μm, the transmittance is almost zero at the center line between the electrodes, while when the distance between electrodes is 17 μm, the transmittance is about 25%. In order to secure the transmittance at the center line of the region between the pixel electrodes 8, the distance between the electrodes is preferably formed to be 20 μm or less.

However, if the distance between the electrodes is too narrow, the aperture ratio decreases due to the part blocked by the electrodes, so that even if the transmittance between the electrodes is high, the transmittance is not so high when viewed as a whole. Therefore, the width and the distance of the electrode must be properly adjusted. In addition, if the width of the electrode is wider, the opening ratio decreases accordingly. Therefore, it is preferable to form the electrode narrowly within the range allowed by the design rule.

If a transparent electrode is used without forming the pixel electrode with an opaque metal or the like, the overall transmittance is increased. In this case, even if the number of electrodes is large, there is no decrease in the aperture ratio. Accordingly, the shorter the distance between the electrodes, the greater the transmittance. .

In this embodiment, a wider viewing angle can be obtained by using the optical phase difference compensation plate between the polarizing plate and the substrate.

In the above embodiments and experimental examples, the type of liquid crystal material, the type of alignment film, the alignment method, the pretilt angle, the direction of the polarizing plate, the cell spacing, the type and presence of the retardation compensation plate, the material forming the electrode, the width and spacing of the electrode, etc. Is changeable according to the design of the liquid crystal display device.

Next, a method of manufacturing a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 6 to 8.

First, as shown in FIG. 6, a Cr, Al, Mo, Ti, Ta film or an alloy film thereof is deposited and patterned on a transparent insulating substrate to form the gate line 20 and the gate electrode 2 that is part of the gate line 20. To form.

Next, as shown in FIG. 7, the gate insulating film 3 made of silicon nitride or the like is stacked to cover the gate line 20, and the amorphous silicon layer 4 and the doped amorphous silicon layer 5 are disposed on the gate insulating film 3. ) Are stacked in succession and then patterned together.

As shown in FIG. 8, Cr, Al, Mo, Ta, or alloys thereof are deposited and patterned to form a data line 60, a source electrode 6, a drain electrode 7, and a pixel electrode 8. After forming, the doped amorphous silicon layer 5 exposed by using the source electrode 6 and the drain electrode 7 as a mask is etched to complete the ohmic contacts 51 and 52.

Finally, as shown in FIG. 2, the protective film 9 is formed on the entire surface of the substrate 10, and the alignment film 30 is printed on the protective film.

The present invention is not limited to the above-described embodiments, and technical details that can be modified or improved by those skilled in the art based on these embodiments are also included in the present invention.

In the liquid crystal display device as in the embodiment of the present invention, by renewing the electrode structure, the viewing angle can be widened, the aperture ratio can be increased, and the deterioration of image quality due to static electricity can be prevented.

Claims (20)

First and second substrates facing each other, A liquid crystal material layer implanted between the first and second substrates and oriented parallel to the first and second substrates, A first electrode formed over the entire surface on the first substrate, A plurality of second electrodes linearly formed on the second substrate; And a polarizing plate attached to outer surfaces of the first and second substrates. In claim 1, The first electrode is a common electrode for applying a common voltage to all the pixels. In claim 2, And the second electrode is a pixel electrode which applies an image signal for displaying an image to each pixel. In claim 3, The first electrode is a liquid crystal display device made of a transparent conductive material. In claim 4, The liquid crystal display device further comprising an alignment layer formed on the first and second electrodes, respectively. In claim 5, And the alignment layers are rubbed in one direction so as to have a predetermined angle with respect to the direction of the second electrode and the direction perpendicular to the second electrode. In claim 6, The transmission axes of the polarizers are perpendicular to each other. In claim 7, The transmission axis of the polarizing plate is parallel to the rubbing direction of the adjacent alignment layer. The compound according to any one of claims 1 to 8, A liquid crystal display device having a spacing between the second electrodes of 20 μm or less. A gate line transferring a scan signal from the outside, a gate electrode connected to the gate line, a gate insulating film covering the gate line and the gate electrode, a semiconductor layer formed on the gate insulating film on the gate electrode, and the semiconductor layer A source electrode and a drain electrode formed on both sides of the gate electrode, and a data line formed on the gate insulating film and transmitting an image signal from the outside and connected to the source electrode, and defined as an intersection of the gate line and the data line. A first substrate formed in at least two linear regions in the pixel area, the first substrate including a pixel electrode connected to each other and connected to the drain electrode, the source and drain electrodes, a data line, and a protective layer covering the pixel electrode; A second substrate including a common electrode formed over the entire surface, And a liquid crystal material layer implanted between the first and second substrates and oriented parallel to the first and second substrates. In claim 10, The common electrode is a liquid crystal display device made of a transparent conductive material. In claim 11, And an alignment layer formed on the passivation layer on the first substrate and on the common electrode on the second substrate. In claim 12, And the alignment layers are rubbed in one direction so as to have a constant angle with respect to the direction of the pixel electrode and the direction perpendicular to the pixel electrode. In claim 13, And a polarizing plate attached to an outer side of the first and second substrates, respectively. The method of claim 14, The transmission axes of the polarizers are perpendicular to each other. The method of claim 15, The transmission axis of the polarizing plate is parallel to the rubbing direction of the adjacent alignment layer. The method according to any one of claims 10 to 16, A liquid crystal display device having a gap between the pixel electrodes of 20 μm or less. Forming a gate line transmitting a scan signal from the outside and a gate electrode connected to the gate line on a transparent insulating substrate; Forming a gate insulating film on the gate line and the gate electrode; Forming a semiconductor layer on the gate insulating film on the gate electrode; Source and drain electrodes are formed on both sides of the gate electrode on the semiconductor layer, and image signals are transmitted from the outside on the gate insulating layer, and data lines connected to the source electrodes are defined as intersections of the gate lines and the data lines. Forming a pixel electrode connected to the drain electrode on the gate insulating layer in the pixel region, And forming a passivation layer covering the source and drain electrodes, the data line, and the pixel electrode. The method of claim 18, And at least two pixel electrodes formed in one pixel region. The method of claim 19, A method of manufacturing a substrate for a liquid crystal display device, wherein the interval between the pixel electrodes is formed to be 20 μm or less.