JP3994743B2 - Method for manufacturing liquid crystal device and liquid crystal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve display quality by preventing an alignment defect at a part with a difference in level on a liquid crystal substrate surface and making alignment uniform over a full screen surface. <P>SOLUTION: A stage 81 and a rubbing roll 83 are freely movable relative to each other. The stage 81 is made to move in a horizontal direction while the rubbing roll 83 is made to rotate. A rubbing operation is carried out by the rotation of the rubbing roll 83 and by the movement of the stage 81. In this case, a direction of the rotation of the rubbing roll 83 is made to coincide with data lines on the liquid crystal substrate and, at the same time, a direction of relative movement of the stage 81 and the rubbing roll 83 is made to incline at an angle specified corresponding to a direction of twist of the liquid crystal with respect to a direction of the data lines on the surface of the liquid crystal substrate 82. Therefore, the surface of the rubbing roll 83 obliquely passes across the part with a difference in level caused by the data lines, the twist of the liquid crystal at the part with a difference in level gets smooth, the alignment defect is prevented, the alignment is made uniform over the full screen surface and picture quality is improved. <P>COPYRIGHT: (C)2003,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a liquid crystal device and a liquid crystal device in which the alignment is made uniform over the entire screen.
[0002]
[Prior art]
A liquid crystal device such as a liquid crystal light valve is configured by sealing liquid crystal between two substrates such as a glass substrate and a quartz substrate. In a liquid crystal light valve, switching elements such as thin film transistors (hereinafter referred to as TFTs) are arranged in a matrix on one substrate, and a counter electrode that supplies a common potential is arranged on the other substrate. Image display is enabled by changing the optical characteristics of the liquid crystal layer sealed between the two substrates in accordance with the image signal.
[0003]
The TFT substrate on which the TFT is disposed and the counter substrate disposed to face the TFT substrate are manufactured separately. Both substrates are bonded together with high accuracy in the panel assembling process, and then liquid crystal is sealed therein. In the panel assembly process, first, an alignment film is formed on the opposing surfaces of the TFT substrate and the counter substrate manufactured in each substrate process, that is, on the surface in contact with the liquid crystal layer of the counter substrate and the TFT substrate, and then the rubbing process. Is done.
[0004]
By forming an alignment film and performing a rubbing treatment, the alignment of liquid crystal molecules when no voltage is applied is determined. The alignment film is formed, for example, by applying polyimide with a thickness of about several tens of nanometers. By forming an alignment film on the surfaces of both substrates facing the liquid crystal layer, the liquid crystal molecules can be aligned along the substrate surface. In the rubbing process, a rubbing roll is disposed in contact with the alignment film, and the alignment film is rubbed while rotating the rubbing roll at a high speed to form fine grooves on the alignment film surface, or a polymer that forms the alignment film. By aligning the direction of the side chain, the film becomes an anisotropic film, and the alignment of the liquid crystal molecules can be defined by subjecting the alignment film to rubbing treatment in a certain direction. When the rotational speed of the rubbing roll is sufficiently larger than the relative moving speed of the rubbing roll and the liquid crystal substrate, the rubbing direction is defined by the rotational direction of the rubbing roller.
[0005]
[Problems to be solved by the invention]
By the way, the transmittance characteristics of the liquid crystal panel are influenced by Δnd of the liquid crystal (Δn is the refractive index anisotropy of liquid crystal molecules, and d is the cell thickness (optical path length)). Δn varies depending on the orientation of the liquid crystal molecules, that is, the alignment state of the liquid crystal molecule assembly. Therefore, when the orientation state is not uniform over the entire screen, the display quality is lowered, and for example, it appears as a rough feeling.
[0006]
In particular, the TFT pixels arranged in a matrix form have a large step in the vicinity of the gate line (scanning line) or source line (data line) direction, and stripe unevenness is likely to occur in this direction due to a decrease in alignment uniformity. there were.
[0007]
The present invention has been made in view of such problems, and the display state can be improved by making the orientation state uniform over the entire screen by setting the rotation direction, the moving direction, the substrate direction, and the like of the rubbing roll. It is an object to provide a method for manufacturing a liquid crystal device and a liquid crystal device.
[0008]
[Means for Solving the Problems]
A method for manufacturing a liquid crystal device according to the present invention includes rubbing the element substrate and the counter substrate in two different rubbing directions so that the liquid crystal is in a twisted nematic mode between the element substrate and the counter substrate. A first procedure for defining a relative traveling direction of at least one liquid crystal substrate of the element substrate and the counter substrate and the rubbing roll, and a first procedure for defining an inclination of the rotation axis of the rubbing roll with respect to the relative traveling direction. The surface having a step extending in a predetermined direction is obtained by moving the liquid crystal substrate and the rubbing roll relative to each other in the relative traveling direction while rotating the rubbing roll around the rotating shaft having an inclination. A third procedure for performing a rubbing process on the liquid crystal substrate, and in the third procedure, among the both side walls of the step extending in a predetermined direction, In the first procedure and the second procedure, the relative traveling direction and the inclination are defined so that the wall that becomes the alignment obstacle of the liquid crystal that is twisted in the direction determined by two different rubbing directions is rubbed by the rubbing roll. It is characterized by doing.
[0009]
According to such a structure, the wall surface which becomes an orientation disorder | damage | failure among the both wall surfaces of a level | step difference is rubbed by a rubbing roll, and the orientation defect can be prevented in the wall surface vicinity which becomes this orientation disorder | damage | failure.
[0010]
In the first procedure, the relative traveling direction of the liquid crystal substrate and the rubbing roll is inclined by a predetermined angle with respect to the predetermined direction, and in the second procedure, the inclination of the rotation axis of the rubbing roll with respect to the relative traveling direction is set to 90 degrees. It is characterized by prescribing.
[0011]
According to such a configuration, the rubbing direction can be inclined by a predetermined angle so that the wall surface that becomes an alignment obstacle among the both side wall surfaces of the step is rubbed by the rubbing roll, and even when the step is an alignment barrier, the step An alignment failure in the vicinity can be prevented.
[0012]
In the first procedure, the relative traveling direction of the liquid crystal substrate and the rubbing roll is tilted by a predetermined angle with respect to the predetermined direction, and in the second procedure, the tilt of the rotation axis of the rubbing roll with respect to the relative traveling direction is twisted of the liquid crystal. A predetermined angle is inclined from 90 degrees based on the direction.
[0013]
According to such a configuration, the movement direction of the rubbing roll surface can be tilted by a predetermined angle so that the wall surface that disturbs the alignment of the liquid crystal among the both side wall surfaces of the step is rubbed by the rubbing roll. Even in the case of the wall surface, it is possible to prevent alignment failure in the vicinity of the step.
[0016]
Further, the step is the largest step among the plurality of steps on the surface of the liquid crystal substrate.
[0017]
According to such a configuration, it is possible to prevent orientation failure at the largest step portion at least and to promote uniform orientation.
[0018]
Further, the step is constituted by data lines or scanning lines which are formed on the liquid crystal substrate and are orthogonal to each other.
[0019]
According to such a configuration, even when a step is formed on the surface of the liquid crystal substrate by the data line or the scanning line, it is possible to prevent alignment defects due to these steps.
[0020]
The counter substrate is rubbed in the scanning line direction, and only the element substrate is rubbed by the first to third procedures.
[0021]
According to such a configuration, it is possible to prevent alignment failure in the vicinity of the data line having a large step.
[0022]
The liquid crystal device according to the present invention is characterized in that a predetermined angle between the rotation direction of the rubbing roll and the predetermined direction is set in a range of 1 to 6 degrees.
[0023]
According to such a configuration, since the rubbing is performed while the surface of the rubbing roll moves along the alignment barrier portion at an inclination angle in the range of 1 to 6 degrees, alignment failure is reliably prevented. The applicant of the present application discloses in Japanese Patent Application No. 2000-248525 filed earlier that the contrast is improved by setting the twist angle within this range.
[0024]
Further, the inclination of the rotation axis of the rubbing roll with respect to the relative traveling direction is set in a range of 10 to 45 degrees.
[0025]
According to such a configuration, since the rubbing is performed while the surface of the rubbing roll moves along the alignment barrier portion at an inclination angle in the range of 10 to 45 degrees, alignment failure is reliably prevented.
[0026]
A liquid crystal device according to the present invention is manufactured by the method for manufacturing a liquid crystal device according to any one of claims 1 to 8.
[0027]
According to such a configuration, the surface of the rubbing roll has a predetermined angle so as to rub up the wall surface that becomes an alignment obstacle based on the direction of twisted alignment of the liquid crystal determined by the two different rubbing directions among the both side wall surfaces of the step. Rubbing is performed while moving at an angle. Therefore, the liquid crystal device is superior in display quality by preventing alignment failure so that the liquid crystal rotates smoothly.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram for explaining a method of manufacturing a liquid crystal device according to the first embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of various elements and wirings in a plurality of pixels constituting the pixel region of the liquid crystal device. FIG. 3 is a plan view of an element substrate such as a TFT substrate as viewed from the counter substrate side together with each component formed thereon, and FIG. 4 is an assembly process in which the element substrate and the counter substrate are bonded together to enclose liquid crystal. It is sectional drawing which cut | disconnects and shows the liquid crystal device after completion | finish at the position of the HH 'line | wire of FIG. FIG. 5 is a cross-sectional view showing the liquid crystal device in detail. FIG. 6 is a flowchart showing the panel assembly process.
[0029]
This embodiment is applied to a twisted nematic mode liquid crystal panel utilizing the optical rotation of light, and the rubbing roll rotation direction and traveling direction, stage traveling direction, substrate orientation, etc. are appropriately set during rubbing. Thus, a uniform alignment state is obtained over the entire screen to improve display quality.
[0030]
First, the structure of the liquid crystal panel will be described with reference to FIGS.
[0031]
As shown in FIGS. 3 and 4, the liquid crystal panel is configured by sealing a liquid crystal 50 between an element substrate 10 such as a TFT substrate and a counter substrate 20. On the element substrate 10, pixel electrodes and the like constituting pixels are arranged in a matrix. FIG. 2 shows an equivalent circuit of elements on the element substrate 10 constituting the pixel.
[0032]
As shown in FIG. 2, in the pixel region, a plurality of scanning lines 3a and a plurality of data lines 6a are wired so as to cross each other, and a pixel electrode is formed in a region partitioned by the scanning lines 3a and the data lines 6a. 9a are arranged in a matrix. A TFT 30 is provided corresponding to each intersection of the scanning line 3 a and the data line 6 a, and the pixel electrode 9 a is connected to the TFT 30.
[0033]
The TFT 30 is turned on by the ON signal of the scanning line 3a, whereby the image signal supplied to the data line 6a is supplied to the pixel electrode 9a. A voltage between the pixel electrode 9 a and the counter electrode 21 provided on the counter substrate 20 is applied to the liquid crystal 50. In addition, a storage capacitor 70 is provided in parallel with the pixel electrode 9a, and the storage capacitor 70 makes it possible to hold the voltage of the pixel electrode 9a for a time that is, for example, three orders of magnitude longer than the time when the source voltage is applied. That is, the storage capacitor 70 improves the voltage holding characteristic and enables image display with a high contrast ratio.
[0034]
FIG. 5 is a schematic cross-sectional view of a liquid crystal panel focusing on one pixel.
[0035]
A groove 11 is formed in the element substrate 10 such as glass or quartz in order to adjust the step shape when the element substrate is completed. A TFT 30 having an LDD structure is formed on the groove 11 with a light shielding film 12 and a first interlayer insulating film 13 interposed therebetween. The groove 11 flattens the boundary surface between the TFT substrate and the liquid crystal 50.
[0036]
The TFT 30 includes a scanning line 3a that forms a gate electrode through an insulating film 2 on a semiconductor layer in which a channel region 1a, a source region 1d, and a drain region 1e are formed. The light shielding film 12 is formed in a region corresponding to the formation region of the TFT 30, a formation region such as a data line 6a and a scanning line 3a described later, that is, a region corresponding to a non-display region of each pixel. The light shielding film 12 prevents incident light from entering the channel region 1 a, the source region 1 d, and the drain region 1 e of the TFT 30.
[0037]
A second interlayer insulating film 14 is stacked on the TFT 30, and a barrier layer 15 is formed on the second interlayer insulating film 14. On the barrier layer 15, a capacitance line 18 is disposed to face the dielectric film 17. The capacitor line 18 includes a capacitor layer and a light shielding layer, and forms a storage capacitor with the barrier layer 15 and has a light shielding function for preventing internal reflection of light. The barrier layer 15 is formed at a position relatively close to the semiconductor layer, so that irregular reflection of light can be efficiently prevented.
[0038]
A third interlayer insulating film 19 is disposed on the capacitor line 18, and a data line 6 a is stacked on the third interlayer insulating film 19. The data line 6a is electrically connected to the source region 1d through contact holes 24a and 24b penetrating the third and second interlayer insulating films 19 and 14. A pixel electrode 9a is stacked on the data line 6a with a fourth interlayer insulating film 25 interposed therebetween. The pixel electrode 9a is electrically connected to the drain region 1e through the capacitor line 18 through contact holes 26a and 26b that penetrate the fourth to second interlayer insulating films 25, 19, and 14. An alignment film 16 made of polyimide polymer resin is laminated on the pixel electrode 9a, and is rubbed in a predetermined direction by the method shown in FIG.
[0039]
When the ON signal is supplied to the scanning line 3a (gate electrode), the channel region 1a becomes conductive, the source region 1d and the drain region 1e are connected, and the image signal supplied to the data line 6a becomes the pixel electrode. 9a.
[0040]
On the other hand, the counter substrate 20 is provided with a first light-shielding film 23 in a region facing the data line 6a, scanning line 3a, and TFT 30 formation region of the TFT array substrate, that is, in a non-display region of each pixel. The first light shielding film 23 prevents incident light from the counter substrate 20 side from entering the channel region 1 a, the source region 1 d, and the drain region 1 e of the TFT 30. A counter electrode (common electrode) 21 is formed over the entire surface of the substrate 20 on the first light shielding film 23. An alignment film 22 made of a polyimide-based polymer resin is laminated on the counter electrode 21 and rubbed in a predetermined direction.
[0041]
A liquid crystal 50 is sealed between the element substrate 10 and the counter substrate 20. Thereby, the TFT 30 writes the image signal supplied from the data line 6a to the pixel electrode 9a at a predetermined timing. The alignment state of the molecular assembly of the liquid crystal 50 changes according to the written potential difference between the pixel electrode 9a and the counter electrode 21 to modulate light and enable gradation display.
[0042]
As shown in FIGS. 3 and 4, the counter substrate 20 is provided with a light shielding film 42 as a frame for partitioning the display area. The light shielding film 42 is formed of, for example, the same or different light shielding material as the light shielding film 23.
[0043]
A sealing material 41 that encloses liquid crystal in a region outside the light shielding film 42 is formed between the element substrate 10 and the counter substrate 20. The sealing material 41 is disposed so as to substantially match the contour shape of the counter substrate 20 and fixes the element substrate 10 and the counter substrate 20 to each other. The sealing material 41 is missing in a part of one side of the element substrate 10, and a liquid crystal injection port 78 for injecting the liquid crystal 50 is formed in the gap between the bonded element substrate 10 and the counter substrate 20. The After the liquid crystal is injected from the liquid crystal injection port 78, the liquid crystal injection port 78 is sealed with a sealing material 79.
[0044]
A data line driving circuit 61 and a mounting terminal 62 are provided along one side of the element substrate 10 in a region outside the sealing material 41 of the element substrate 10, and scanning lines are provided along two sides adjacent to the one side. A drive circuit 63 is provided. On the remaining side of the element substrate 10, a plurality of wirings 64 are provided for connecting between the scanning line driving circuits 63 provided on both sides of the screen display area. In addition, a conductive material 65 for electrically connecting the element substrate 10 and the counter substrate 20 is provided in at least one corner of the counter substrate 20.
[0045]
Next, the panel assembly process will be described with reference to FIG. The element substrate 10 (TFT substrate) and the counter substrate 20 are manufactured separately. In the next steps S2 and S7, polyimide (PI) to be the alignment films 16 and 22 is applied to the TFT substrate and the counter substrate 20 prepared in steps S1 and S6, respectively. Next, in steps S3 and S8, the alignment film 16 on the surface of the element substrate 10 and the alignment film 22 on the surface of the counter substrate 20 are rubbed.
[0046]
Next, a cleaning process is performed in steps S4 and S9. This cleaning process is for removing dust generated by the rubbing process. When the cleaning process is completed, a sealing material 41 (see FIG. 3) is formed in step S5. Next, in step S10, the element substrate 10 and the counter substrate 20 are bonded together, and in step S11, pressure bonding is performed while alignment is performed, and the sealing material 41 is cured. Finally, in step S12, liquid crystal is sealed from a notch provided in a part of the sealing material 41, and the notch is closed to seal the liquid crystal.
[0047]
Next, the reason for setting the rubbing angle will be described with reference to FIGS. FIG. 7 is an explanatory diagram for explaining the alignment state of the liquid crystal panel.
[0048]
This embodiment is applied to a twisted nematic mode liquid crystal panel using the optical rotation of light.
[0049]
FIG. 7 schematically shows a state where a light transmission state is observed with a polarization microscope in a twist nematic mode liquid crystal panel using a TFT substrate in which data lines and gate lines are arranged in a matrix in the horizontal and vertical directions. ing. 7 is rubbed in the rubbing direction shown in FIG. 7 and 8 are views seen from the counter substrate side, as in FIG. The relationship between the step sizes is an example of data line> gate line.
[0050]
In FIG. 7, the filled lattice-like portion 71 indicates a black matrix formed on the counter substrate. Moreover, the plain area | region 72 in FIG. 7 has shown the part with a uniform orientation state. A hatched region 73 in FIG. 7 indicates a portion where the alignment state is unstable. The region 73 having a poor alignment state is along the data line of the TFT substrate. That is, this region 73 corresponds to one side surface of the portion where the TFT substrate surface has a step.
[0051]
As shown in FIG. 8, the rubbing direction of the TFT substrate is from the lower side to the upper side in the vertical direction, and in the vicinity of the TFT substrate, the liquid crystal molecules have a tilt with the lower side adjacent to the TFT substrate and the upper side spaced apart from the TFT substrate. On the other hand, the rubbing direction of the counter substrate is from the right to the left in the horizontal direction. In the vicinity of the counter substrate, the liquid crystal molecules have a tilt in which the right side is adjacent to the counter substrate and the left side is separated from the counter substrate. That is, with reference to the direction of the liquid crystal molecules adjacent to the counter substrate side, the liquid crystal molecules rotate 90 degrees counterclockwise between the counter substrate and the TFT substrate when no voltage is applied.
[0052]
Therefore, in the rubbing state of FIG. 8, considering the tilt of the liquid crystal molecules on the TFT substrate side, it is considered that the rotation of the liquid crystal molecules is hindered when there is a step on the left side of the liquid crystal molecules when viewed from the panel surface side. . On the other hand, when the rubbing direction is as shown in FIG. 9, the step due to the data line on the right side of the liquid crystal molecules as viewed from the panel surface side becomes a barrier.
[0053]
That is, liquid crystal molecules are likely to be disturbed in the vicinity of these step barriers. In the TFT panel, a step is generated on the substrate surface also by a signal line, a capacitor line, a light-shielding film, and the like, and an alignment failure occurs in these step portions.
[0054]
Therefore, in the present embodiment, in consideration of the occurrence of alignment failure depending on the tilt direction of the liquid crystal molecules, that is, the rubbing direction and the step direction, the direction of the signal line that causes the step is determined. By tilting the rubbing direction, the alignment failure is suppressed. Thereby, in the present embodiment, the alignment state is also improved in the step portion of the liquid crystal panel, and a uniform alignment state is obtained over the entire screen.
[0055]
In FIG. 1, a liquid crystal substrate 82 is placed on a stage 81. The example of FIG. 1 is an example in which the relationship of the rubbing direction between the TFT substrate and the counter substrate has the relationship shown in FIG. The liquid crystal substrate 82 is the element substrate 10 described above, and the alignment film is formed in step S2 in FIG. If there is a step on the surface of the counter substrate 20, the counter substrate 20 may be rubbed by the method shown in FIG.
[0056]
The rubbing roll 83 is configured in a cylindrical shape, and is rotatable in the circumferential direction around the center of the circle as an axis 84. A rubbing cloth made of, for example, rayon is attached to the peripheral surface of the rubbing roll 83. The tip of the rayon extends from the surface of the rubbing cloth. The rubbing roll 83 and the stage 81 are positioned in the vertical direction so that the rubbing pressure on the liquid crystal substrate 82 by the rubbing cloth becomes a predetermined value.
[0057]
The stage 81 and the rubbing roll 83 are relatively movable, and FIG. 1 shows that the rubbing roll 83 moves relative to the stage 81 in the horizontal direction indicated by the arrow 85, for example. The stage 81 is moved in the horizontal direction while rotating the rubbing roll 83, and the entire surface of the liquid crystal substrate 82 is rubbed with a rubbing cloth by the rotation of the rubbing roll 83 and the movement of the stage 81.
[0058]
In the present embodiment, the liquid crystal substrate 82 is disposed at a predetermined angle with respect to the relative movement direction of the rubbing roll 83 and the stage 81.
[0059]
Accordingly, the rubbing direction indicated by the arrow 85 in FIG. 1 is inclined at a predetermined angle with respect to the vertical direction of the liquid crystal substrate 82. That is, in this case, the rubbing direction is shifted by a predetermined angle with respect to the wiring direction of the data line. As is clear from comparison between FIG. 1 and FIGS. 7 and 8, a rubbing roll 83 is provided from the lower side to the upper side of the step with respect to the wall surface that tends to cause orientation failure among the both side wall surfaces of the step due to the data line or the like. Set to progress.
[0060]
In the embodiment configured as described above, rubbing is performed in the direction indicated by the arrow 85 in FIG. That is, the surface of the rubbing roll 83 gives an alignment failure to the step due to the data line of the liquid crystal substrate 82 when the relationship in the rubbing direction between the liquid crystal substrate 82 and the counter substrate is the relationship shown in FIG. Proceed from the lower side of the wall to the upper side.
[0061]
In the rubbing treatment in the present embodiment, the rubbing cloth is performed so as to advance in a direction to rub up the stepped wall surface that causes an alignment failure. The liquid crystal substrate 82 thus rubbed is bonded to the counter substrate with the relationship shown in FIG. Then, with reference to the direction of the liquid crystal molecules adjacent to the counter substrate side, the liquid crystal molecules on the TFT substrate side rotate clockwise toward the counter substrate side when no voltage is applied.
[0062]
In this case, the alignment state of the liquid crystal molecules adjacent to the TFT substrate in the vicinity of the step wall near the step wall that causes alignment failure is regulated so as to cross the step diagonally in the vicinity of the step wall and tilt along the rubbing direction by the rubbing cloth. Is formed. Therefore, the liquid crystal molecules are easy to rotate clockwise even in the vicinity of the step barrier, and it is possible to prevent the alignment state from becoming poor in the vicinity of the step barrier.
[0063]
As described above, in the present embodiment, the rubbing direction is inclined by a predetermined angle with respect to the direction of the step in accordance with the liquid crystal twist direction, thereby preventing the occurrence of alignment failure near the step barrier. This makes it possible to improve the display quality by making the orientation state uniform over the entire screen.
[0064]
Although the rubbing direction on the TFT substrate side is inclined by a predetermined angle with respect to the step such as the data line, the counter substrate side is also inclined by a predetermined angle so that the twist angle differs by 90 degrees depending on the rubbing direction on the TFT substrate side. A rubbing process may be performed. If the twist angle does not need to be set to 90 degrees, the counter substrate side may be rubbed in a rubbing direction that matches the horizontal or vertical axis of the substrate.
[0065]
The angle between the step direction and the relative traveling direction of the rubbing roll 83 and the stage 81 is preferably set in the range of 1 to 6 degrees. In this angle range, the orientation state tends to be good. Further, when the rubbing direction of the counter substrate is made to coincide with the horizontal axis, the twist angle is 91 to 96 degrees, and as disclosed in Japanese Patent Application No. 2000-248525 filed earlier by the present applicant, the contrast characteristics. Becomes better.
[0066]
FIG. 10 is an explanatory view showing a second embodiment of the present invention. In FIG. 10, the same components as those in FIG.
[0067]
This embodiment is applied to a method in which rubbing is performed in a state where the relative movement direction of the stage 81 and the rubbing roll 83 is inclined by a predetermined angle in accordance with the liquid crystal twist direction with respect to the rotation direction of the rubbing roll 83.
[0068]
In the first embodiment, the rubbing direction is inclined with respect to the step direction, thereby preventing the occurrence of alignment failure near the step barrier. However, since the rubbing direction is inclined with respect to the direction of the step, that is, the direction of the data line, it is difficult to set the reference axis in the rotation direction in the manufacturing process.
[0069]
Therefore, in the present embodiment, the rubbing direction is made to coincide with the step direction, and the rubbing roll is made to advance from the lower side to the upper side of the wall surface that is likely to cause an alignment failure, so that the surface of the rubbing cloth advances. It is possible to prevent the occurrence and facilitate the setting of the rotation direction reference axis in the manufacturing process.
[0070]
In the present embodiment, as shown in FIG. 10, the liquid crystal substrate 82 is staged so that the direction of the data lines or the like constituting the step matches the rotation direction of the rubbing roll 83 defined by the direction of the shaft 84. 81. An arrow 96 indicates the rotational speed direction of the rubbing roll 83. An arrow 95 indicates the relative movement direction of the stage 81 and the rubbing roll 83 in the horizontal direction.
[0071]
The rotational speed of the rubbing roll 83 is extremely high with respect to the relative movement speed of the rubbing roll 83 and the stage 81, and the rubbing direction substantially coincides with the rotational direction of the rubbing roll 83.
[0072]
However, the relative movement direction of the rubbing roll 83 and the stage 81 is inclined with respect to the step such as the data line of the liquid crystal substrate 82. In the present embodiment, the rubbing roll 83 also has a step due to the data line or the like. It sets so that it may progress toward the upper side from the lower side of a level | step difference with respect to the wall surface which tends to give an orientation disorder among both wall surfaces.
[0073]
As described above, in this embodiment, by performing bias rubbing, the rubbing direction is made to coincide with the step direction by the data line or the like, and the relative movement direction of the rubbing roll 83 and the stage 81 is twisted with respect to the step. It is inclined at a predetermined angle according to the direction. As a result, the liquid crystal molecules easily rotate even in the vicinity of the step barrier, and no alignment failure occurs.
[0074]
Also in the present embodiment, it is desirable that the angle between the step direction and the relative traveling direction of the rubbing roll 83 and the stage 81 is set in a range of 10 to 45 degrees. In this angle range, the orientation state tends to be good.
[0075]
FIG. 11 shows a state in which the light transmission state of the liquid crystal panel manufactured according to the second embodiment is observed with a polarization microscope, as in FIG. FIG. 12 shows an example in which the inclination angle of the rubbing direction with respect to the step is set without considering the twist direction of the liquid crystal molecules. 11 and 12 are examples in the case where the same rubbing direction as in FIG. 8 is set.
[0076]
When the rubbing roll 83 is rubbed upward from the lower side to the upper side of the step barrier as in the second embodiment, as is apparent from the comparison between FIG. 11 and FIG. Has a relatively uniform orientation. On the other hand, FIG. 12 shows an example in which the rubbing roll 83 is rubbed while being rubbed from the upper side to the lower side of the step barrier. In this case, the region 94 is non-uniformly oriented.
[0077]
As described above, the rubbing roll surface advances while scrubbing the step barrier from the lower side to the upper side, so that it is possible to prevent the occurrence of alignment failure in the vicinity of the step barrier.
[0078]
【The invention's effect】
As described above, according to the present invention, it is possible to improve the display quality by making the orientation state uniform over the entire screen by setting the rotation direction, the moving direction, the substrate direction, and the like of the rubbing roll.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for explaining a manufacturing method of a liquid crystal device according to a first embodiment of the invention.
FIG. 2 is an equivalent circuit diagram of various elements and wirings in a plurality of pixels constituting a pixel region of the liquid crystal device.
FIG. 3 is a plan view of an element substrate such as a TFT substrate as viewed from the counter substrate side together with each component formed thereon.
4 is a cross-sectional view of the liquid crystal device after the assembly process in which liquid crystal is sealed by bonding an element substrate and a counter substrate, cut along the line HH ′ of FIG. 3;
FIG. 5 is a cross-sectional view illustrating a liquid crystal device in detail.
FIG. 6 is a flowchart showing a panel assembly process.
FIG. 7 is an explanatory diagram showing a light transmission state of a liquid crystal panel in a twisted nematic mode.
FIG. 8 is an explanatory diagram showing rubbing directions of the counter substrate and the TFT substrate.
FIG. 9 is an explanatory diagram for explaining a rubbing direction and an alignment barrier of a counter substrate and a TFT substrate.
FIG. 10 is an explanatory diagram showing a second embodiment of the present invention.
FIG. 11 is an explanatory diagram showing a light transmission state of a twisted nematic mode liquid crystal panel according to the second embodiment.
FIG. 12 is an explanatory diagram showing an example when the inclination angle of the rubbing direction with respect to the step is set without considering the twist direction of the liquid crystal molecules.
[Explanation of symbols]
81 ... Stage 82 ... Liquid crystal substrate 83 ... Rubbing roll 85 ... Relative movement direction

Claims (9)

A liquid crystal device manufacturing method comprising rubbing the element substrate and the counter substrate in two different rubbing directions so that the liquid crystal is in a twisted nematic mode between the element substrate and the counter substrate,
A first procedure for defining a relative traveling direction of at least one liquid crystal substrate of the element substrate and the counter substrate and a rubbing roll;
A second procedure for defining an inclination of a rotation axis of the rubbing roll with respect to the relative traveling direction;
While the rubbing roll is rotated around the inclined rotation axis, the liquid crystal substrate and the rubbing roll are relatively advanced in the relative traveling direction, thereby providing a surface having a step extending in a predetermined direction. And performing a rubbing process on the liquid crystal substrate,
In the third procedure, of the both side wall surfaces of the step extending in the predetermined direction, a wall surface that becomes an alignment obstacle of the liquid crystal that is twisted and aligned in a direction determined by the two different rubbing directions is the rubbing roll. A method of manufacturing a liquid crystal device, wherein the relative traveling direction and the inclination are defined in the first procedure and the second procedure so as to be rubbed by each other. In the first step, the relative traveling direction of the liquid crystal substrate and the rubbing roll is inclined by a predetermined angle with respect to the predetermined direction,
2. The method of manufacturing a liquid crystal device according to claim 1, wherein the second procedure defines an inclination of a rotation axis of the rubbing roll with respect to the relative traveling direction as 90 degrees. In the first step, the relative traveling direction of the liquid crystal substrate and the rubbing roll is inclined by a predetermined angle with respect to the predetermined direction,
2. The liquid crystal device according to claim 1, wherein in the second step, the inclination of the rotation axis of the rubbing roll with respect to the relative traveling direction is inclined by a predetermined angle from 90 degrees based on a twist direction of the liquid crystal. Production method.   The method for manufacturing a liquid crystal device according to claim 1, wherein the step is the largest step among the plurality of steps on the surface of the liquid crystal substrate.   2. The method of manufacturing a liquid crystal device according to claim 1, wherein the step is constituted by data lines or scanning lines which are formed on the liquid crystal substrate and are orthogonal to each other. Rubbing the counter substrate in the scanning line direction;
4. The method of manufacturing a liquid crystal device according to claim 3, wherein only the element substrate is rubbed by the first to third procedures.   4. The method of manufacturing a liquid crystal device according to claim 1, wherein a predetermined angle between the rotation direction of the rubbing roll and the predetermined direction is set in a range of 1 to 6 degrees.   4. The method of manufacturing a liquid crystal device according to claim 1, wherein an inclination of a rotation axis of the rubbing roll with respect to the relative traveling direction is set in a range of 10 to 45 degrees.   A liquid crystal device manufactured by the method for manufacturing a liquid crystal device according to claim 1.

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