JP2012018256A - Method for exposing alignment film for liquid crystal and device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a practical problem in that a conventional exposure method of irradiating an alignment film with an optical pattern via a mask takes a long exposure time when irradiating the alignment film of a liquid crystal substrate with an optical pattern of fine-pitch linear lines in a single direction gives the alignment film a uniform alignment characteristic (pretilt angle) according to the scanning direction of irradiation.SOLUTION: In a method of exposing an alignment film for liquid crystal by giving exposure light emitted from a light source polarization characteristics, making the light incident to a micro-mirror device having a large number of minute movable mirrors and projecting via a projection optical system a pattern of exposure light reflected in a reflection pattern formed by the minute movable mirrors of the micro-mirror device on a substrate that is mounted on a stage and on whose surface the alignment film is formed, while the substrate is moved continuously in a single direction by moving the stage, the alignment film is exposed to the pattern of exposure light that is moved at a lower speed than the moving speed of the stage.

Description

  The present invention relates to a method for producing a liquid crystal display element, and more particularly to a liquid crystal alignment film exposure method and apparatus for imparting alignment characteristics to a liquid crystal alignment film by an optical technique.

  A liquid crystal display element is required to have high image quality and high definition in order to display more information with higher quality as a display of a large television, a 3D television, a personal computer, or a mobile terminal.

  In order to realize high image quality and high definition of this liquid crystal display element, an arrangement (orientation) of molecules of liquid crystal material to be sealed between a pair of opposing glass substrates constituting the liquid crystal display element is formed on the glass substrate. It is necessary to make it uniform on the optically transparent electrode (transparent electrode).

  In order to make the alignment (alignment) of the molecules of the liquid crystal material uniform, a method of forming an alignment film on a transparent electrode conventionally formed on a glass substrate and rubbing the alignment film with a cloth to impart alignment characteristics Was used. However, in this method, a part of the alignment film is peeled off and fine dust is generated, which may cause an element defect or it is difficult to provide uniform alignment characteristics over the entire display area of the glass substrate, resulting in higher definition. This is a problem in forming a simple display element.

  For example, Non-Patent Document 1 proposes an optical rubbing method that imparts alignment characteristics in a non-contact manner by irradiating the alignment film with light as a technique for replacing the alignment film with the alignment film by this rubbing method. . This is because the irradiation region is continuously moved in one direction while irradiating the polymer film, which is an alignment film material, with a plurality of linear light beams formed at a pitch of 14 μm from the vertical direction, to the surface of the polymer film. This is a method of imparting liquid crystal alignment ability. It is described that the orientation characteristics change depending on the scanning direction of the irradiated light. Patent Document 1 also describes a similar optical rubbing method.

  In Patent Document 2, two types of alignment regions having different pretilt directions are formed on two opposing glass substrates in order to increase the viewing angle of a liquid crystal display device, improve display quality, and improve contrast. In addition, it is described that a two-divided alignment state is obtained by bonding two glass substrates so that the boundaries between the alignment regions are orthogonal to each other. As an alignment treatment method for the alignment film, it is described that the alignment film is subjected to any one of a rubbing method, an ion beam irradiation method, and a light irradiation method in a state where a region to which no alignment characteristic is imparted is masked.

JP 2004-145141 A JP-A-11-352486

Masayuki Kimura, Shoichi Tanaka et al .: New photo-alignment process for inducing a stable pretilt angle on a photo-alignment film: JSR TECHINICAL REVIEW No. 111/2004

    In the method described in Non-Patent Document 1, the scanning speed of the irradiated linear light is 34 μm / sec, whereas in the method described in Patent Document 1, the irradiated linear light is The scanning speed is 100 μm / sec. This is because, for example, when processing a liquid crystal substrate having a side length of 1 m, it takes 7.5 hours in the method of Non-Patent Document 1 to scan light once, and approximately It takes 2.8 hours, and considering the fact that scanning is performed a plurality of times by changing the scanning direction on the substrate in order to give a plurality of alignment characteristics, it is far from the practical processing speed.

  In addition, the method described in Patent Document 2 requires the use of a photomask in order to impart alignment characteristics only to a desired portion of the substrate. Particularly in a production line using a large mother substrate, an expensive photomask is created for each product. This is a heavy burden in terms of manufacturing costs. In addition, the liquid crystal panel manufactured by this method is a method in which the alignment is regulated in a direction twisted by 90 degrees above and below the liquid crystal, and is compared to the alignment direction providing method in which the alignment is regulated in a vertical or inversely flat direction. , Response speed may decrease.

  An object of the present invention is to provide a liquid crystal alignment film exposure method and apparatus capable of forming a photoalignment film at a practical processing speed by solving the above-described conventional technical problems. .

  In order to achieve the above object, in the present invention, an exposure apparatus that exposes an alignment film for liquid crystal, a stage unit that can move by placing a substrate having an alignment film formed on the surface, and an exposure light are emitted. A light source, a polarization characteristic imparting means for imparting polarization characteristics to the exposure light emitted from the light source, and a part of the exposure light imparted with the polarization characteristic by the polarization characteristic imparting means reflected by a pattern formed by a minute movable mirror Pattern forming means, a projection optical unit for exposing the alignment film by irradiating the substrate mounted on the stage means with the exposure light pattern reflected by the pattern forming means, and a control means for controlling the whole The control means controls the stage means and the pattern forming means, and moves the stage means continuously in one direction, whereby the pattern of exposure light is continuously moved on the substrate moving in one direction. But And configured to expose the alignment film moves at a slower speed than the moving speed of the stage means.

  In order to achieve the above-described object, in the present invention, an exposure apparatus that exposes the alignment film for liquid crystal includes a stage unit that can move by placing a substrate having an alignment film formed on the surface, and ultraviolet light or A light source that emits light close to ultraviolet light as exposure light, a polarization property imparting means that imparts polarization characteristics to the exposure light emitted from this light source, and a polarization property imparting means that includes a large number of small movable mirrors Pattern forming means for forming a linear light pattern with a fine pitch by reflecting the applied exposure light and reflecting with a pattern formed by a minute movable mirror, and a fine pitch formed by this pattern forming means And a projection optical unit that exposes the alignment film by irradiating the substrate placed on the stage means with a linear exposure light pattern, and the pattern forming means is placed on the stage means in one direction The alignment film is exposed by moving a linear exposure light pattern with a fine pitch on a continuously moving substrate in a direction opposite to one direction at a speed slower than the moving speed of the stage means. Configured.

  Furthermore, in order to achieve the above-described object, in the present invention, the exposure light emitted from the light source is given polarization characteristics and is incident on a micromirror device having a large number of microscopic movable mirrors. Alignment for liquid crystal that exposes the alignment film by projecting the pattern of exposure light reflected by the reflection pattern formed by the movable mirror onto the substrate on which the alignment film is formed on the surface via the projection optical system In the method of exposing the film, the stage of the stage is moved continuously in one direction, and the pattern of the exposure light moves on the substrate that is continuously moving in one direction at a speed slower than the moving speed of the stage. The film was exposed.

  By using the alignment film exposure apparatus for liquid crystal according to the present invention configured as described above, the subpixel of the liquid crystal panel is divided into four regions, and the alignment film regulation direction of each region is reversely flat between the TFT and the upper and lower substrates of the color filter. In addition, the tilt direction of the liquid crystal due to voltage application can be 45 °, 135 °, 225 °, 315 ° with respect to the vertical end surface of the substrate, or ± 22.5 ° with respect to the uniaxial positive and negative directions, respectively. A liquid crystal panel with a wide viewing angle and quick response can be manufactured.

  According to the present invention, it is possible to form a photo-alignment film that replaces the conventional rubbing method at a practical processing speed, and to realize a liquid crystal display element with higher image quality and higher definition.

It is a block diagram which shows the whole structure of the alignment film exposure apparatus for liquid crystals. It is a top view of a micromirror device. It is a side view of a micromirror device element explaining operation of one element of a micromirror device. It is a perspective view which shows the structure of a projection optical part and a stage part. It is the top view of the element of the micromirror device which showed typically the time change of the element of a micromirror device and a substrate-like exposure field in an exposure process. It is a front view of the micromirror device which formed the linear exposure pattern. It is a front view of a micromirror device showing a state where a linear exposure pattern is transferred for one line in the Y direction. It is a block diagram which shows the structure in 2nd Embodiment of a projection optical part. In the second embodiment of the projection optical unit, a plan view of a 30 μm square region on the substrate showing a state in which a minute spot light is irradiated on a two-dimensional region of 30 μm square on the substrate and one row of micromirror devices It is a top view. It is a front view of 1 pixel of the liquid crystal substrate which shows distribution of the pretilt angle of the alignment film in 1 pixel. It is a front view of a liquid crystal substrate which shows the state where the pretilt angle of four directions was given to each pixel in a liquid crystal substrate. It is the front view of the liquid crystal substrate which showed typically the direction which provides a pretilt angle in the 1st exposure process. It is the front view of the liquid crystal substrate which showed typically the direction which provides a pretilt angle in the 2nd exposure process. It is the front view of the liquid crystal substrate which showed typically the direction which provides a pretilt angle in the 3rd exposure process. It is the front view of the liquid crystal substrate which showed typically the direction which provides a pretilt angle in the 4th exposure process. FIG. 4 is a front view of one pixel of a liquid crystal substrate showing a pretilt angle distribution of ± 22.5 degrees with respect to the X-axis positive and negative directions of the alignment film in one pixel. FIG. 3 is a front view of the liquid crystal substrate showing a state in which pre-tilt angles in four directions of ± 22.5 degrees with respect to the X-axis direction are given to each pixel in the liquid crystal substrate. FIG. 10B is a front view of the liquid crystal substrate schematically showing a direction in which a pretilt angle corresponding to the direction of 1043 in FIG. 10A is given in the first exposure step. FIG. 10B is a front view of the liquid crystal substrate schematically showing a direction in which a pretilt angle corresponding to the direction of 1044 in FIG. 10A is given in the second exposure step. FIG. 10B is a front view of the liquid crystal substrate schematically showing a direction in which a pretilt angle corresponding to the direction of 1042 in FIG. 10A is given in the third exposure step. FIG. 10B is a front view of a liquid crystal substrate schematically showing a direction in which a pretilt angle corresponding to the direction of 1041 in FIG. 10A is given in a fourth exposure step. It is a flowchart which shows the flow of a process of the exposure process for repeating the operation of the Y direction of a liquid crystal substrate, and forming the pretilt angle of 4 directions for every pixel in an alignment film. It is a flowchart which shows the flow of the process of the exposure process which repeats repeating the operation of the Y direction of a liquid crystal substrate, and forming the pretilt angle of 4 directions for every pixel in an alignment film, moving a scanning area | region to a X direction.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the overall configuration of a liquid crystal alignment film exposure apparatus according to this embodiment. The alignment film exposure apparatus for liquid crystal controls the stage unit 110 on which the substrate 100 is placed, the exposure optical system 120 for exposing the alignment film formed on the surface of the substrate 100, the stage unit 110, and the exposure optical system 120. A system 130 and a substrate surface height detection system 140 are provided.

  The stage unit 110 is moved in the X-axis direction that is movable in the X-axis direction, the Y-stage 112 that is movable in the Y-direction orthogonal to the X-axis direction, and the Z-axis direction (height direction) orthogonal to the X-axis and Y-axis. A possible Z stage 113 and a θ stage 114 rotatable about the Z axis are provided. The substrate 100 is held on the θ stage 114.

  The exposure optical system 120 includes a light source 121 that emits ultraviolet light (UV light) or light close to the ultraviolet region, a polarizing plate 122 that controls the polarization state of light emitted from the light source 121, and an optical path of light that has passed through the polarizing plate 122. , A micromirror device 124 composed of a large number of fine movable mirrors, a light path switched by the mirror 123 and incident on the micromirror device 124, and the light reflected by the micromirror device 124 is condensed to form a substrate The projection optical unit 125 that exposes the alignment film formed on the surface of 1 is provided.

  The control system 130 includes a light source control unit 131 that controls the light source 121, a micromirror device control unit 132 that controls the micromirror device 124, a stage control unit 133 that controls each stage of the stage unit 110, and an overall control unit 134 that controls the whole. It has.

  The substrate surface height detection system 140 emits light having a wavelength different from the light emitted from the light source 121 and having a wavelength that does not affect the alignment film formed on the surface of the substrate 100 with the exposure optical system 120. A height detection light source 141 that irradiates in the vicinity of a region irradiated with exposure light from an oblique direction, and light (regular reflection light) emitted from the height detection light source 141 and reflected from the surface of the substrate 100. And a reflected light detector 142 for detection. During exposure of the substrate 100 by the exposure optical system 120, a signal obtained by detecting the reflected light from the substrate 100 by the reflected light detector 142 is sent to the overall control unit 134 and processed to obtain height information on the surface of the substrate 100. The overall controller 134 controls the Z stage 113 via the stage controller 133 so that the surface of the substrate 100 maintains a predetermined height based on the height information.

  FIG. 2A shows a plan view of the micromirror device 124. In the micromirror device 124, minute movable mirrors 1242 are arranged in an array in a frame part 1241, and each of the minute movable mirrors 1242 is controlled by the micromirror device control unit 132 so that each of the minute movable mirrors 1242 has two inclinations. You can switch between angles. That is, as shown in FIG. 2B, when the movable mirror 1242 is maintained at the tilt angle indicated by the solid line (on) as controlled by the micromirror device control unit 132 (on), the light path is emitted from the light source 121 and the optical path through the mirror 123. The incident light after being bent is reflected in the direction of the projection optical unit 125 by the movable mirror 1242, passes through the projection optical unit 125, reaches the substrate 100, and exposes the alignment film formed on the surface of the substrate 100. On the other hand, when the movable mirror 1242 is maintained at the tilt angle indicated by the dotted line as controlled by the micromirror device controller 132 (off), the incident light reflected by the mirror 123 is projected by the movable mirror 1242. The light is reflected in the direction away from the portion 125, does not reach the substrate 100, and does not contribute to the exposure of the alignment film formed on the surface of the substrate 100.

  The pattern formed by the movable mirrors 1242 arranged in the X direction in FIG. 2A (the combination of ON and OFF of each movable mirror 1242) is moved on the micromirror device 124 by moving in the Y direction at predetermined time intervals. A pattern based on a combination of turning on and off the mirror 1242 can be sent in the Y direction at a constant speed.

  That is, in the configuration shown in FIG. 1, the light emitted from the light source 121, reflected by the mirror 123 and incident on the micromirror device 124 is controlled by the micromirror device controller 132 and shown by the solid line in FIG. 2B. Only the light reflected by the minute mirror 1242 set at a predetermined angle enters the projection optical unit 125 and reaches the substrate 100.

  Next, a first embodiment of the projection optical unit 125 will be described with reference to FIGS. FIG. 3A is a perspective view of the stage unit 110 including the projection optical unit 125. The micromirror device 124 is installed with an inclination of θ with respect to the moving direction of the Y stage 112.

The relationship between the small area 101 moving in the Y direction and the pixel pattern transferred onto the small area 101 will be described with reference to FIG. In FIG. 4, for ease of explanation, movable mirrors 1242-1 to 1242-6 arranged in a line in the Y direction of the micromirror device 124 and the substrate 100 continuously moving in the Y direction (the direction of the arrow 50). The temporal change in the relationship with the region 111 (indicated by a two-dot chain line) sequentially irradiated by the movable mirrors 1242-1 to 1242-6 is shown above. Pt ₁ to Pt ₆ on the left side of FIG. 4 represent the positions of the region 111 on the substrate 100 moving at a constant speed in the Y direction from time t ₁ to time t ₆ at equal intervals.

The pitch between each of the movable mirrors of the movable mirror 1242-1～1242-6 in a row of micro-mirror device 124 is P, the substrate 100 at regular intervals of time from time _{t 1} to time _{t 6} in the Y-direction The feed pitch is PP. In this embodiment, the feed pitch PP in the Y direction of the substrate 100 is set slightly larger than the pitch P between the movable mirrors. As a result, the position of the region 111 on the substrate 100 from the time t ₁ to the time t ₆ is gradually shifted from the positions of the movable mirrors 1242-1 to 1242-6 arranged in a line of the micro mirror device 124.

That is, assuming that sequentially projected to the region 111 on the substrate 100 moves in the Y direction 1243 points plotted in the same position on each of the movable mirrors 1242-1～1242-6 from time _{t 1} over the _{t 6,} the state As shown on the right side of FIG. As a result, the region 111 on the substrate 100 moving at a constant speed in the Y direction is sequentially irradiated by the movable mirrors 1242-1 to 1242-6 aligned in the Y direction of the micromirror device 124 at time t. so that moves gradually from ₁ toward t _6. Therefore, the exposure time of the region 111 on the substrate 100 can be set to a desired value by appropriately setting the feed pitch PP in the Y direction of the substrate 100 with respect to the pitch P between the movable mirrors.

  For example, when the transfer pixel size of the micromirror device 124 is C, and the feed pitch PP is 21 / 20C, the transfer pitch TP is 1 / 20C. Therefore, when the stage speed V is 2 mm / s, the transfer pixel scan speed is 100 μm / s.

The point 1243 shown in FIG. 4 is replaced with a linear light pattern formed by the plurality of movable mirrors 1242 shown in FIGS. 5A and 5B, and applied to the entire surface of the substrate 100, thereby scanning the linear light pattern. Thus, the entire surface of the substrate 100 can be exposed in a desired time. In the example shown in FIGS. 5A and 5B, the movable mirrors 1242-1, -2,... N arranged in alignment in the XY direction of the micromirror device 124 are turned on and off every other column in the X direction. These patterns are arranged, and after this, the substrate 100 is PP-moved in the Y direction from the state shown in FIG. 8A and then sequentially sent in one row in the Y direction as shown in FIG. 5B. As a result, the entire surface of the substrate 100 is scanned with a linear repetitive pattern by the difference between the feed amount in the Y direction of the on and off patterns by the micromirror device 124 and the amount of movement of the substrate 100 in the Y direction within the same time. The structure to be shown is shown. In the example shown in FIGS. 5A and 5B, the pattern in the X direction is uniform. Actually, however, the ON and OFF areas are also in the X direction according to the exposure area on the substrate 100. Is formed. In the example shown in FIGS. 5A and 5B, an example in which a linear repetitive pattern is formed for each line of one line in the X direction of the micromirror device is shown. Alternatively, the width between the on pattern and the off pattern may be changed.
In the example shown in FIGS. 3 and 4, the direction in which the movable mirrors 1242-1 to 1242-6 arranged in a row in the micromirror device 124 are inclined by an angle θ with respect to the feeding direction (Y direction) of the substrate 100. ing. This is because the transfer pixels of the micromirror device 124 are aligned with a position resolution equal to or less than the transfer pixel pitch C. For example, when θ = 1/256 rad and the transfer pixel pitch is 10 μm, transfer can be performed with a position resolution of 10/256 = 0.039 μm by selecting a transfer pixel.

  Next, a second embodiment of the projection optical unit 125 will be described with reference to FIG. The projection optical unit 125 condenses the magnifying lens 1251 that magnifies the light reflected by the micromirror device 124, the array lens 1253 that condenses the light magnified by the magnifying lens 1251, and the array lens 1253, respectively. An objective lens 1254 is provided for projecting the spot of light thus produced at an equal magnification onto an alignment film formed on the surface of the substrate 100.

Here, the movable mirrors 1242 of the micromirror device 124 are two-dimensionally arranged at a pitch of 10.8 μm. When the magnification ratio of the magnification lens 1251 is set to 2.78 times, the individual microlenses 1252 of the array lens 1253 are What is necessary is just to form with a 30 micrometer pitch. Further, when the NA of each micro lens 1252 is 0.07 and the wavelength of light emitted from the light source 121 is 365 nm, the spot diameter of the light collected by each micro lens 1252 is 6.4 μm. .
If there is no array lens 1253, the transfer pixel size is 30 μm, but this configuration enables pattern transfer with a resolution of 6.4 μm. The light reflected by the micromirror device 124 is collected by the array lens 1253 and irradiated onto the alignment film formed on the surface of the substrate 100 as a set of 6.4 μm spot lights.
Here, FIG. 7 shows a state in which one row of pixels of the micromirror device 124 is transferred into a two-dimensional area of 30 μm square. As shown on the left side of FIG. 7, when one column of the micromirror device 124 is 1024 pixels, the inclination angle θ2 in the column direction of the micromirror device 124 is 1/1024 rad (horizontal direction when 1024 pixels are separated in the vertical direction). And the pitch of pixels transferred by the micromirror device 124 (size of one pixel region on the substrate 100) is C, the feed pitch PP of the substrate 100 is C * 33 / By setting the number to 32, 32 * 32 points are transferred to a two-dimensional area of one pixel of 30 μm square on the substrate 100 as shown on the right side of FIG.

  That is, when the size of one pixel region is 30 μm and the feed pitch PP of the substrate 100 is 30 * 33/32 = 30.9375 μm, the light spot is fed in the feed direction of the substrate 100 in one pixel region of 30 μm square ( In the vertical direction of FIG. 7, 32 spots are irradiated with an inclination of an angle θ with respect to the feed direction of the substrate 100 over a length of 30 μm at a pitch of 0.9375 μm. The 33rd light spot is the first light spot because the irradiation position of the light spot on the substrate 100 is shifted by one pixel in the feed direction of the substrate 100 with respect to the irradiation area of the first light spot. With respect to the irradiation area of the light spot, the image is transferred at a position 30 * 32/1024 = 0.9375 μm away from the feeding direction of the substrate 100 in a direction perpendicular to the feeding direction. By repeating such scanning in a direction perpendicular to the feed direction of the substrate 100 at a pitch of 0.9375 μm, a spot of 1024 pixels in the column direction of the micromirror device 124 is irradiated to one pixel region of the substrate 100. The

  Each point on the right side of FIG. 7 corresponds to a pixel of the micromirror device, and a 6.4 μm spot light pattern can be drawn in a two-dimensional region by turning each pixel on and off. If the feed pitch PP is 30 * 33/32 = 30.9375 μm, the ratio of the stage speed to the light spot scan speed is 30: 0.9375, the stage speed is 3.2 mm / s, and the light spot is 100 μm / s. Low-speed scanning can be realized.

  Next, a method for performing an optical rubbing process on the alignment film formed on the surface of the substrate 100 using the exposure apparatus shown in FIG. 1 will be described.

  FIGS. 8A and 8B show a region for imparting alignment characteristics to the alignment film in the region for one pixel of the liquid crystal display device formed on the substrate 100.

  Patent Document 2 discloses a method of forming four types of alignment states by giving different alignment characteristics of 180 degrees to both alignment films of a pair of glass substrates constituting a liquid crystal display device and combining them. However, in this embodiment, four kinds of alignment states are formed on one glass substrate, and the treatment for imparting alignment characteristics to the other substrate is not performed.

  That is, in this embodiment, as shown in FIG. 8A, an area 101 corresponding to one pixel on the substrate 100 is divided into four small areas 1011, 1012, 1013, and 1014, and each divided small area is divided. Different alignment characteristics are imparted to the alignment films (set to different pretilt angles). Arrows 1021, 1022, 1023, and 1024 in FIG. 8A indicate orientation characteristics directions (directions to which a pretilt angle is given), respectively.

  FIG. 8B schematically shows a state in which many regions 101 corresponding to one pixel are formed on the substrate 100. The actual liquid crystal substrate has 1920 pixels in the horizontal direction and 1080 pixels in the vertical direction (full high-definition specification).

  Next, with reference to FIGS. 9A to 9D and the flowcharts of FIGS. 12 and 13, a method for imparting orientation characteristics in different directions as indicated by arrows 1021, 1022, 1023, and 1024 in FIG. 8A. explain.

  When the alignment film is irradiated with a linear light pattern with a fine pitch and scanned in one direction, uniform alignment characteristics (pretilt angle) according to the scanned direction are imparted to the alignment film. In the present embodiment, by utilizing this property, first, as shown in FIG. 9A, the small area 1011 in the area 101-1 corresponding to one pixel on the substrate 100 and the adjacent area corresponding to the area 101-1. A region corresponding to a small region 1011 inside each pixel region (101-2 to 101-9 in the example of FIG. 9A) is scanned while irradiating a linear light pattern with a fine pitch through the projection optical unit 125. Thus, the alignment film formed on the surface of the substrate 100 is exposed. The scanning of the linear light pattern is performed by moving the Y stage with respect to the projection optical unit 125 at a constant speed. As the Y stage moves, the micromirror device control unit 132 controls the individual movable mirrors 1242 of the micromirror device 124, so that the small area 1011 in the area 101 corresponding to one pixel on the substrate 100. In addition, irradiation is performed while continuously moving the linear light pattern in the Y direction in an area corresponding to the small area 1011 of each adjacent pixel area corresponding to the area 101.

Returning to FIG. 9A and FIG. In a state where the orientation of the substrate 100 placed on the θ stage 114 is inclined by an angle θ with respect to the Y direction, the stage driving means 133 drives the Y stage 112 to move the substrate 100 at a constant speed in the Y direction (S1201). . At this time, the moving speed of the substrate 100 in the Y direction is set slightly higher than the moving speed of the pattern in the Y direction of each movable mirror 1242 of the micromirror device 124 (each movable mirror in the X direction of the micromirror device 124). While the pattern formed in 1242 is transferred by one column in the Y direction, the distance that the substrate 100 moves in the Y direction is slightly larger than one pitch of the movable mirrors 1242 arranged in the Y direction of the micromirror device 124. In this manner, the moving speed of the Y-axis stage 112 and the Y-direction pattern feed speed of the micromirror device 124 are set. As a result, each minute region (indicated by 1011 in FIG. 8A: first region) with an arrow in FIG. 9A is irradiated with a linear light pattern of equal pitch formed by the micromirror device 124. By scanning in this manner, a pretilt angle can be given to the alignment film formed on the surface of the substrate 100 in the direction indicated by the arrow in each region.
When the Y stage 112 continues to move in the Y direction and reaches a moving end in the Y direction (end point: not shown) (S1202), the movement of the Y stage is temporarily stopped. Next, the area of each pixel on the substrate 100 corresponding to 1012 in FIG. 8A while moving the Y stage 112 in a direction (reverse direction) opposite to that in FIG. 9A at a constant speed as in FIG. 9A. By exposing the (second region) with a linear repeating pattern formed by the micromirror device 124 (S1203), the alignment film formed on the surface of the substrate 100 is shown in each region as shown in FIG. 9B. A pretilt angle can be given in the direction opposite to that described in 9A.
When the Y stage 112 is moved in the reverse direction to reach the moving end (start point: not shown) (S1204), the θ stage 114 is rotated 90 degrees (S1205).

Next, while moving the Y stage 112 at a constant speed in the same direction as in FIG. 9A, the region (third region) of each pixel on the substrate 100 corresponding to 1013 in FIG. By exposing with the formed linear repeating pattern (S1206), a pretilt angle can be given to the orientation film formed on the surface of the substrate 100 in the direction as shown in FIG. 9C in each region.
When the Y stage 112 reaches the moving end (end point: not shown) in the Y direction (S1207), the movement of the Y stage is temporarily stopped. Next, while moving the Y stage 112 in the opposite direction (reverse direction) to that of FIG. 9C at a constant speed as in the case of FIG. 5C, the area of each pixel on the substrate 100 corresponding to 1014 in FIG. 8A. 9C is exposed in a linear repetitive pattern formed by the micromirror device 124 (S1208), and as shown in FIG. 9D, the alignment film formed on the surface of the substrate 100 is explained in FIG. 9C in each region. A pretilt angle can be given to the opposite direction. When the Y stage 112 reaches a moving end in the Y direction (start point: not shown) (S1209), the movement of the Y stage is stopped.

  In the state shown in FIG. 9A, when the width in the X direction of the substrate 100 is larger than the exposure width in the X direction performed in one exposure, before the θ stage 114 is rotated 90 degrees in S605 in the flow of FIG. The stage 111 is driven so that the adjacent exposure region on the substrate 100 is positioned below the projection exposure unit 125, and steps S601 to S604 are repeated, so that the first region and the second region of each pixel are repeated over the entire surface of the substrate 100. The area is exposed. The flow is shown in FIG.

  10 and 11, another embodiment of the pretilt angle will be described. The apparatus configuration and processing flow in this embodiment are the same as those in the first embodiment.

  In FIG. 10A, the directions to which the pretilt angle is given are arrows 1041, 1042, 1043, and 1044, for example, ± 22.5 degrees with respect to the positive or negative direction of the X axis. By setting such an angle, the visibility with respect to the viewing angle can be improved. FIG. 10B shows the direction of the pretilt angle of ± 22.5 degrees on the substrate 100. 11A to 11D show pretilt angle application directions by stage scanning. FIG. 11A is a front view of a liquid crystal substrate schematically showing a direction in which a pretilt angle corresponding to the direction 1043 in FIG. 10A is given in the first exposure step, and FIG. 11B is a front view of 1044 in FIG. 10A in the second exposure step. FIG. 11C is a front view of the liquid crystal substrate schematically showing the direction for giving the pretilt angle corresponding to the direction, and FIG. 11C schematically shows the direction for giving the pretilt angle corresponding to the direction 1042 in FIG. 10A in the third exposure step. FIG. 11D is a front view of the liquid crystal substrate schematically showing the direction in which the pretilt angle corresponding to the direction 1041 in FIG. 10A is applied in the fourth exposure step.

  In the state of FIG. 11B, by rotating the θ stage 114 by 45 degrees in S1205 of the flow of FIG. 12, a pretilt angle of 22.5 degrees can be given to each region.

  Thus, the direction of the desired pretilt angle can be set according to the rotation amount of the stage 114, and it becomes possible to cope with the improvement of the viewing angle for each product.

  In the flowchart shown in FIG. 13, S1301 to S1304 are the same as the processes from S1201 to S1204 described in FIG. In the processing from S1201 to S1204, when the exposure of the first region and the second region on the alignment film is completed for the first region along the X direction, it is checked whether the scanning in the X direction is completed (S1305). If not completed, the X stage 111 is driven to position the next exposure area below the projection exposure unit 125 in the X direction (S1306), and the processes from S1301 to S1304 are executed. This is repeated until the processing is completed for all regions in the X direction on the substrate 100.

  If it is determined that scanning in the X direction has been completed, the θ stage 114 is then rotated 90 degrees (S1307), and the same processing as in steps S1206 to S1209 described in FIG. 12 is performed in steps S1308 to S1311. When the exposure of the third region and the fourth region on the alignment film is completed for the first region along the X direction in the processing from S1308 to S1311, it is checked whether the scanning in the X direction is completed (S1312). If not completed, the X stage 111 is driven to position the next exposure region below the projection exposure unit 125 in the X direction (S1313), and the processing from S1308 to S1311 is executed. This is repeated until the exposure of the third region and the fourth region of each pixel is completed for all regions in the X direction on the substrate 100. When it is determined that scanning in the X direction is complete, the entire process is terminated.

  By performing the above-described processing on the entire display region of the substrate 100, a pretilt angle as shown in FIGS. 9A to 9D is applied to each of the regions divided into four with respect to the alignment film formed on the surface of each pixel. As a result, as shown in FIG. 8B, it is possible to obtain liquid crystal display elements having different polarization characteristics in four regions in one pixel over the entire surface of the substrate 100 as shown in FIG. 8B. became.

  As mentioned above, although the invention made by the present inventor has been specifically described based on the embodiments, it is needless to say that the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof. Yes.

DESCRIPTION OF SYMBOLS 110 ... Stage part 111 ... X stage 112 ... Y stage 113 ... Z stage 114 ... θ stage 120 ... Exposure optical system 121 ... Light source 122 ... Polarizing plate 123 .. Mirror 124 ... Micromirror device 125 ... Projection optical unit 130 ... Control unit 131 ... Light source control unit 132 ... Micromirror device control unit 133 ... Stage control unit 134 ... Overall control unit 140... Substrate surface height detection system 141... Height detection light source unit 142.

Claims (16)

An exposure apparatus that exposes an alignment film for liquid crystal,
Stage means capable of moving by placing a substrate having an alignment film formed on the surface;
A light source that emits exposure light;
Polarization property imparting means for imparting polarization property to exposure light emitted from the light source;
Pattern forming means for reflecting a part of the exposure light imparted with polarization characteristics by the polarization characteristic imparting means with a pattern formed by a minute movable mirror;
A projection optical unit that exposes the alignment film by irradiating a substrate mounted on the stage unit with a pattern of exposure light reflected by the pattern forming unit;
A control means for controlling the whole, and the control means controls the stage means and the pattern forming means, and continuously moves in one direction by moving the stage means continuously in one direction. An alignment film exposure apparatus for liquid crystal, wherein the alignment film is exposed by moving a pattern of the exposure light on the substrate at a speed slower than a moving speed of the stage means.   The control means controls the stage means and the pattern forming means to expose the first region of the alignment film on the substrate with the exposure light while continuously moving the stage means in one direction. And exposing the second region different from the first region of the alignment film on the substrate with the exposure light while continuously moving the stage means in a direction opposite to the one direction. The alignment film exposure apparatus for liquid crystal according to claim 1.   2. The alignment film exposure apparatus for liquid crystal according to claim 1, wherein the stage means comprises a linear stage capable of reciprocating on a straight line and a rotatable θ stage. An exposure apparatus that exposes an alignment film for liquid crystal,
Stage means capable of moving by placing a substrate having an alignment film formed on the surface;
A light source that emits ultraviolet light or light close to ultraviolet light as exposure light;
Polarization property imparting means for imparting polarization property to exposure light emitted from the light source;
By providing a large number of minute movable mirrors and exposing the exposure light imparted with polarization characteristics by the polarization characteristic imparting means and reflecting it with a pattern formed by the minute movable mirrors, a linear light pattern with a fine pitch is formed. Pattern forming means to be formed;
A projection optical unit configured to irradiate the alignment film by irradiating a substrate placed on the stage unit with a fine pitch linear exposure light pattern formed by the pattern forming unit;
The pattern forming means is configured to apply the fine pitch linear exposure light pattern on the substrate that is placed on the stage means and continuously moves in one direction, based on the moving speed of the stage means. An alignment film exposure apparatus for liquid crystal, wherein the alignment film is exposed by moving in a direction opposite to the one direction at a slow speed.   While the stage means is continuously moved in one direction, the first region of the alignment film on the substrate is exposed with the exposure light, and the stage means is continuously moved in a direction opposite to the one direction. 5. The alignment film exposure apparatus for liquid crystal according to claim 4, wherein a second region different from the first region of the alignment film on the substrate is exposed with the exposure light.   5. The alignment film exposure apparatus for liquid crystal according to claim 4, wherein the stage means includes a linear stage capable of reciprocating on a straight line and a rotatable θ stage.   In the micromirror device, the micro movable mirrors are two-dimensionally arranged, and the arrangement of the linear directions in which the stage means of the micro movable mirrors arranged in two dimensions reciprocally move is The liquid crystal alignment film exposure apparatus according to claim 1, wherein the liquid crystal alignment film exposure apparatus is inclined with respect to a direction.   8. The alignment film exposure apparatus for liquid crystal according to claim 1, further comprising height detection means for detecting the height of the surface of the substrate placed on the stage means. Applying polarization characteristics to the exposure light emitted from the light source and making it incident on a micromirror device equipped with a large number of small movable mirrors,
A pattern of exposure light reflected by a reflection pattern formed by a minute movable mirror of the micromirror device is projected onto a substrate having an alignment film formed on a surface placed on a stage via a projection optical system. A method of exposing an alignment film for liquid crystal that exposes the alignment film,
By moving the stage continuously in one direction, the pattern of the exposure light moves at a speed slower than the moving speed of the stage on the substrate that is continuously moving in one direction. An alignment film exposure method for liquid crystal, comprising exposing.   The first region of the alignment film on the substrate is exposed with the exposure light while continuously moving the stage in one direction, and the substrate is continuously moved in a direction opposite to the one direction. 10. The alignment film exposure method for liquid crystal according to claim 9, wherein a second region different from the first region of the upper alignment film is exposed with the exposure light.   After exposing the first region and the second region of the alignment film on the substrate, the substrate is rotated at an arbitrary angle to expose the third region and the fourth region on the substrate. The alignment film exposure method for liquid crystals according to claim 9.   A large number of pixels are formed in alignment on the substrate, and the substrate is placed on the stage so that the alignment direction of the pixels on the substrate is inclined at an arbitrary angle with respect to one direction in which the stage moves. The alignment film exposure method for liquid crystal according to claim 9, wherein the alignment film is exposed to light.   After exposing the first region and the second region of the alignment film on the substrate, the substrate is rotated 90 degrees to expose the third region and the fourth region on the substrate. The alignment film exposure method for liquid crystal according to claim 9, characterized in that:   A large number of pixels are formed in alignment on the substrate, and the substrate is placed on the stage so that the alignment direction of the pixels on the substrate is inclined 45 degrees with respect to one direction in which the stage moves. 12. The alignment film exposure method for liquid crystal according to claim 9, wherein the alignment film is exposed to light.   The micro movable mirrors constituting the micro mirror device are arranged in a two-dimensional manner inclined with respect to one direction in which the stage is continuously moved, and reflected by the micro movable mirrors arranged in an inclined manner. 13. The alignment film exposure method for liquid crystals according to claim 9, wherein the alignment film on the substrate placed on the stage is exposed with an exposure pattern.   During the exposure of the alignment film on the substrate, the height of the surface of the substrate placed on the stage is optically detected, and the height of the surface of the substrate is adjusted based on the detected result. The alignment film exposure method for liquid crystal according to any one of claims 9 to 12.

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