Patent Publication Number: US-9427915-B2

Title: Exposure device

Description:
The present application is a Continuation application of U.S. patent application Ser. No. 13/824,263, filed on Mar. 15, 2013, which is based on International Application No. PCT/JP2011/068576, filed on Aug. 16, 2011, which is based on the Japanese Patent Application No. 2010-208773, filed on Sep. 17, 2010, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to an exposure device for producing, by a multidomain exposure technique, an alignment material film for a liquid crystal display device that displays three-dimensional images; and relates in particular to an exposure device for photoalignment of an alignment material film by splitting portions of the alignment material film which correspond to picture elements of the liquid crystal display device into two parts, and exposing these from different directions; or by exposing portions which correspond to pixels from a different direction in each adjacent pixel in the width direction thereof. 
     BACKGROUND ART 
     In the past, liquid crystals constituted by calamitic molecules comprising a plurality of benzene or cyclohexane molecules with modifying groups at both ends have been used in liquid crystal displays and like, for example. Adjustments to viewing angle and contrast of the display are made by causing the calamitic liquid crystals to orient in a uniform direction. 
     In the past, to orient the liquid crystal molecules, an alignment film comprising, for example, a polyimide or the like, is formed on the surface of the glass substrates for sandwiching the liquid crystals, thereby orienting the liquid crystal molecules in a predetermined direction coincident with the alignment direction of the alignment film, through sandwiching of the liquid crystals between the alignment films. 
     In one example of a production method adopted when forming an oriented film on the surface of a glass substrate, a polyimide solution, for example, is coated and baked onto the glass substrate, forming a polyimide film (alignment material film) several tens of nanometers thick, and thereafter the surface of the polyimide film (alignment material film) is rubbed in one direction with a rubbing roller having cloth wound about the surface (for example, Patent Document 1). 
     However, with methods that involve orienting the liquid crystal molecules by forming an alignment film on a glass substrate surface, due to the adoption of production methods like that described above to form the alignment film, the alignment film may become scratched by rubbing cloth that is shed by the roller as it is rubbed or by dust sloughed off from the polyimide film or the like, or the dust itself may become deposited on the surface of the alignment film. A resultant problem is that this tends to lead to display nonuniformities and display defects of the liquid crystal display. 
     In order to solve this problem, there has recently been proposed a technique, called photoalignment, which uses ultraviolet light to align the alignment material film. Specifically, by irradiating an alignment material film of polyimide, azobenzene, or the like with linear polarized or unpolarized ultraviolet light, the alignment material film becomes aligned in the same direction, due to its photodegradation characteristics. Consequently, alignment films of good alignment can be formed by a non-contact process, preventing display nonuniformities and display defects of the liquid crystal displays and the like. 
     However, with photoalignment, in the event that the alignment material film is irradiated with ultraviolet light exclusively from a single direction, the alignment direction of the alignment film will be a single direction only, and therefore the liquid crystal molecules sandwiched between the alignment films will orient in a single given direction exclusively. A consequent problem is that the liquid crystal display or the like will have a narrow viewing angle. 
     In order to solve this problem, there has recently been proposed an alignment material film exposure technique called multidomain alignment (for example, in Patent Documents 2 to 4).  FIG. 9  is a schematic view showing exposure in conventional multidomain alignment, wherein  FIG. 9 ( a )  is a side view showing multidomain alignment exposure in a conventional exposure unit, and  FIG. 9 ( b )  is a perspective view thereof. As shown in  FIG. 9 , in an exposure unit of employing a multidomain alignment system, exposure light  11   a ,  12   a  from two different light sources (a first light source  11  and a second light source  12 ) is output at mutually different output angles, whereupon the exposure light  11   a ,  12   a  is transmitted through a mask  13  disposed between the first light source  11 , the second light source  12 , and a member for exposure  2 .  FIG. 10  is a drawing showing the mask in this multidomain alignment system exposure unit, and an alignment film formed by a single exposure. As shown in  FIG. 9 ( b ) , the mask  13  is constituted by a frame  130  and a pattern formation portion  131  at the center thereof; as shown in  FIG. 10 , a first light-transmitting region group  131   a  and a second light-transmitting group  131   b  in each of which a plurality of light transmission regions are arrayed in one row are formed in the pattern formation portion  131 , in correspondence with the respective exposure light from the first light source  11  and the second light source  12 . The first light-transmitting region group  131   a  and the second light-transmitting group  131   b  are disposed spaced apart in the relative scanning direction of the alignment material film with respect to the mask  13 , with the respective plurality of light transmission regions corresponding to regions split to one-half the picture element width. The light transmission regions of the first light-transmitting region group  131   a  and the second light-transmitting group  131   b  are arrayed with gaps between them, so that there is no overlap in the scanning direction. As shown in  FIG. 10 ( b ) , the respective light transmission regions of the first and the second light-transmitting group  131   a ,  131   b  are formed such that a plurality thereof (in  FIG. 10  ( b ), six) are lined up in the scanning direction. By irradiating these respectively different regions  131   a,    131   b  of the mask  13  from different directions with the exposure light  11   a ,  12   a  from the first and second light sources  11 ,  12 , the light transmitted through the light transmission regions irradiates and exposes the alignment material film on the surface of the member for exposure  2 , which is supported on a stage  15 . In so doing, through a single exposure, in both the direction of split (width direction) of the picture elements and the lengthwise direction perpendicular thereto (the scanning direction), respectively, the alignment material film is exposed by the exposure light transmitted through the plurality of light transmission regions, forming an alignment film in such a way that a plurality of regions, which correspond to picture elements and have uniform alignment direction, line up in the width direction and lengthwise direction, as shown in  FIG. 10 ( c ) . 
     In this case, due to the respectively different angles of slope of the exposure light  11   a ,  12   a  with respect to the surface being exposed, an alignment film aligned in two directions is obtained. Consequently, sections that will constitute the R (red), G (green), and blue (B) picture elements of a liquid crystal display or the like are split into halves respectively irradiated by the exposure light  11   a ,  12   a . In so doing, two alignment directions of the alignment film are created within each single picture element of the liquid crystal display or the like, and the liquid crystal molecules can be oriented in two directions. In so doing, the viewing angle of the liquid crystal display or the like can be made wider. Moreover, in a multidomain alignment system exposure unit such as this, rather than lining up a plurality of the light transmission regions of the mask shown in  FIG. 10  in the scanning direction, the light transmission regions could instead be constituted to extend in the scanning direction, making these light transmission regions correspond to regions that include a plurality of pixels lined up in the scanning direction; and by continuously transmitting light through these light transmission regions, regions having uniform alignment directions can be formed in the alignment film so as to extend in a band in the scanning direction. In so doing, an alignment film in which each of the regions that will constitute adjacent pixels in the width direction has a different alignment direction is manufactured. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     
         
         Patent Document 1: Japanese Laid-open Patent Application 2009-294609 
         Patent Document 2: Japanese Laid-open Patent Application 2010-39485 
         Patent Document 3: Japanese Laid-open Patent Application 2001-42365 
         Patent Document 4: Japanese Laid-open Patent Application 2003-43492 
       
    
     DISCLOSURE OF THE INVENTION 
     Problems the Invention is Intended to Solve 
     However, the aforedescribed prior art has problems such as the following. In a multidomain alignment system exposure unit, the mask stage  14  that supports the mask  13  is disposed towards one of the two light sources. Consequently, the conventional exposure unit has the problem that, in cases in which the direction in which the alignment film is to be aligned necessitates a small angle of the exposure light  11   a  with respect to the surface being exposed, the top part of the mask stage  14  (section A in  FIG. 11 ) will be positioned on the optical path of the exposure light  11   a , as shown in  FIG. 11 , and will interfere with the exposure light  11   a , so that the alignment film cannot be exposed in the predetermined pattern. 
     Moreover, as shown in  FIGS. 9 to 11 , in the conventional exposure unit, the exposure light  11   a ,  12   a  output from the first and second light sources  11 ,  12  are respectively transmitted through regions that respectively lie closer towards the light source side from the mask  13 . Consequently, in a case in which the angle of the exposure light  11   a ,  12   a  with respect to the surface being exposed is small, it is necessary for the distance between the first and second light sources  11 ,  12  to be long, creating the problem of a larger size of the exposure device. 
     With the foregoing in view, it is an object of the present invention to provide an exposure device for manufacture, through exposure by a multidomain alignment system, of an alignment material film for use in a liquid crystal display device that displays three-dimensional images, wherein the exposure device can expose the alignment material film to a predetermined pattern in the normal fashion, even in cases necessitating a small slope angle of the exposure light with respect to the surface being exposed, so that a more compact size is possible. 
     Means for Solving the Problems 
     The exposure device according to the present invention is an exposure device for splitting sections of an alignment material film corresponding to picture elements of a liquid crystal display device into two parts in the width direction thereof and exposing the film from different directions, whereby the alignment material film is photoaligned; the exposure device having: a first and a second light source for outputting exposure light; a mask in which there are formed a first light transmission region group and a second light transmission region group in which a plurality of light transmission regions for transmitting the exposure light from the first and second light sources is arrayed in single rows; and a mask support portion for supporting the mask, the mask support portion being disposed towards the first light source; the first and second light transmission region groups being disposed spaced apart in the direction of relative scanning of the alignment material film with respect to the mask; the plurality of light transmission regions respectively corresponding to regions equivalent to one-half of one picture element split in the width direction; the light transmission regions of the first light transmission region group and the light transmission regions of the second light transmission region group being arrayed with intervals therebetween such that there is no overlap in the scanning direction; and the exposure light from the first light source and the second light source being caused to mutually intersect on the optical path between the first and second light sources and the alignment material film so that regions of the alignment material film which correspond to split regions of picture elements are irradiated. This exposure device splits in two the picture elements of the liquid crystal display device in the width direction, and exposes the regions in such a way that the respective alignment directions thereof are different directions, and is suited to forming an aligned film having a wide viewing angle. 
     Another exposure device according to the present invention is an exposure device for splitting sections of an alignment material film corresponding to picture elements of a liquid crystal display device into two parts in the width direction thereof and exposing the film from different directions, whereby the alignment material film is photoaligned; the exposure device having: a first and a second light source for outputting exposure light; a first mask in which is formed a first light transmission region group in which a plurality of light transmission regions for transmitting the exposure light from the first light source is arrayed in a single row; a first mask support portion for supporting the first mask, the mask support portion being disposed towards the second light source; a second mask in which is formed a second light transmission region group in which a plurality of light transmission regions for transmitting the exposure light from the second light source is arrayed in a single row; and a second mask support portion for supporting the second mask, the mask support portion being disposed towards the first light source; the respective plurality of the light transmission regions of the first and second light transmission region groups corresponding to regions equivalent to one-half of one picture element split in the width direction; and the exposure light from the first light source and the second light source being caused to mutually intersect on the optical path between the first and second light sources and the alignment material film so that regions of the alignment material film which correspond to split regions of picture elements are irradiated. This exposure device splits in two the picture elements of the liquid crystal display device in the width direction, and exposes display device in the width direction, and exposes the in such a way that the alignment directions thereof are different directions, and is suited to forming an aligned film having a wide viewing angle. 
     Yet another exposure device according to the present invention is an exposure device for causing sections of an alignment material film corresponding to pixels of a liquid crystal display device to be exposed from a different direction for each adjacent pixel in the width direction thereof, whereby the alignment material film is photoaligned; the exposure device having: a first and a second light source for outputting exposure light; a mask in which there are formed a first light transmission region group and a second light transmission region group in which a plurality of light transmission regions for transmitting the exposure light from the first and second light sources is arrayed in single rows; and a mask support portion for supporting the mask, the mask support portion being disposed towards the first light source; the first and second light transmission region groups being disposed spaced apart in the direction of relative scanning of the alignment material film with respect to the mask; the respective plurality of light transmission regions corresponding to regions that include a plurality of pixels lined up in the scanning direction; the light transmission regions of the first light transmission region group and the light transmission regions of the second light transmission region group being arrayed with intervals therebetween such that there is no overlap in the scanning direction; and the exposure light from the first light source and the second light source being caused to mutually intersect on the optical path between the first and second light sources and the alignment material film so that regions in the alignment material film that correspond to the regions including a plurality of pixels lined up in the scanning direction are irradiated. This exposure device exposes the pixels of a liquid crystal display device in such a way that the alignment direction is a different direction for each adjacent pixel in the width direction thereof, and is suitable, for example, to form a polarizing film for use as a polarizing film in a 3D display. 
     Yet another exposure device according to the present invention is an exposure device for causing sections of an alignment material film corresponding to pixels of a liquid crystal display device to be exposed from a different direction for each adjacent pixel in the width direction thereof, whereby the alignment material film is photoaligned; the exposure device having: a first and a second light source for outputting exposure light; a first mask in which is formed a first light transmission region group in which a plurality of light transmission regions for transmitting the exposure light from the first light source is arrayed in a single row; a first mask support portion for supporting the first mask, the mask support portion being disposed towards the second light source; a second mask in which is formed a second light transmission region group in which a plurality of light transmission regions for transmitting the exposure light from the second light source is arrayed in a single row; and a second mask support portion for supporting the second mask, the mask support portion being disposed towards the first light source; the respective plurality of the light transmission regions of the first and second light transmission region groups corresponding to regions that include a plurality of pixels lined up in the scanning direction; and the exposure light from the first light source and the second light source being caused to mutually intersect on the optical path between the first and second light sources and the alignment material film so that regions of the alignment material film that correspond to the regions including a plurality of pixels lined up in the scanning direction are irradiated. This exposure device exposes the pixels of a liquid crystal display device in such a way that the alignment direction is a different direction for each adjacent pixel in the width direction thereof; and is suitable, for example, to form a polarizing film for use as a polarizing film in a 3D display. 
     In the exposure device according to the present invention, the position of intersection of exposure light from the first light source and exposure light from the second light source is between the first and second light sources and the mask, for example. Alternatively, the position of intersection of exposure light from the first light source and exposure light from the second light source is between the mask and the alignment material film. 
     Effect of the Invention 
     In the exposure device according to the present invention, exposure light from the first light source and exposure light from the second light source are caused to intersect on the optical path between the first and second light sources and the alignment material film, and irradiate regions that correspond to split regions of the picture elements, or to regions including a plurality of pixels lined up in the scanning direction, in the alignment material film. In so doing, the distance between the light sources can be shorter, as compared to the case in which the exposure light does not intersect. Therefore, as compared with conventional exposure devices, the exposure device of the present invention has a wider range in which irradiation can take place free from interference of the device with the exposure light, and the alignment material film can be exposed in the normal manner, even when the angle of the exposure light with respect to the surface being exposed is small. 
     Moreover, because the distance between the light sources can be shorter, the device can be more compact overall. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1 ( a )  is a side view showing multidomain alignment by an exposure device according to a first embodiment of the invention, and ( b ) is a perspective view thereof; 
         FIG. 2 ( a )  is a plan view showing a mask in the exposure device according to the first embodiment of the invention, ( b ) is an enlarged view of section A showing a portion of a light transmission region group in  FIGS. 2 ( a ), and ( c )  is a diagram showing an alignment film formed by a single exposure in the exposure device according to the first embodiment of the invention; 
         FIG. 3  is a schematic diagram showing the relationship of the mask and the exposure light in the exposure device according to the first embodiment of the invention; 
         FIGS. 4 ( a ) and ( b )  are diagrams showing a modification of the mask in the exposure device according to the first embodiment of the invention, and ( c ) is a diagram showing an alignment film formed by the mask of  FIGS. 4 ( a ) and ( b ) ; 
         FIG. 5 ( a )  is a side view showing multidomain alignment exposure by an exposure device according to a second embodiment of the invention, and ( b ) is a perspective view thereof; 
         FIG. 6  is a schematic diagram showing the relationship of the mask and the exposure light in the exposure device according to the second embodiment of the invention; 
         FIG. 7 ( a )  is a side view showing multidomain alignment exposure by an exposure device according to a third embodiment of the invention, and ( b ) is a perspective view thereof; 
         FIG. 8  is a plan view showing the mask in the exposure device according to a third embodiment of the invention; 
         FIG. 9 ( a )  is a side view showing multidomain alignment exposure by a conventional exposure device, and ( b ) is a perspective view thereof; 
         FIG. 10 ( a )  is a plan view showing a mask in a conventional exposure device, ( b ) is an enlarged view of section A showing a portion of a light transmission region group in  FIGS. 10 ( a ), and ( c )  is a diagram showing an alignment film formed by a single exposure in the conventional exposure device; and 
         FIG. 11  is a schematic diagram showing the relationship of the mask and the exposure light in the conventional exposure device. 
     
    
    
     EMBODIMENTS FOR CARRYING OUT THE INVENTION 
     The embodiments of the present invention are described in specific terms below, making reference to the accompanying drawings. Firstly, the constitution of an exposure device of a first embodiment is described.  FIG. 1 ( a )  is a side view showing multidomain alignment by an exposure device according to a first embodiment of the invention, and ( b ) is a perspective view thereof.  FIG. 2 ( a )  is a plan view showing a mask in the exposure device according to the first embodiment of the invention,  FIG. 2 ( b )  is an enlarged view of section A showing a portion of a light transmission region group in  FIG. 2 ( a ) , and  FIG. 2( c )  is a diagram showing an alignment film formed by a single exposure in the exposure device according to the first embodiment of the invention.  FIG. 3  is a schematic diagram showing the relationship of the mask and the exposure light in the exposure device according to the first embodiment of the invention. In the present embodiment, a case in which the light transmission regions are constituted so as to extend in the scanning direction, with each light transmission region corresponding to a region that includes a plurality of pixels lined up in the scanning direction, and regions of uniform alignment direction are formed to extend in a band in the scanning direction, through continuous exposure. 
     As shown in  FIG. 1 , the exposure device  1  is constituted by two light sources (a first light source  11  and a second light source  12 ) for outputting exposure light  11   a ,  12   a ; a mask  13  having a pattern formed on the surface; and a mask stage  14  for supporting the mask  13 . A member for exposure  2  (for example, a glass substrate with an alignment material film formed on the surface) supported on a stage  15  is irradiated with the exposure light  11   a ,  12   a , and aligned in predetermined directions. In  FIGS. 1, 2 , and other drawings, the member for exposure  2  is shown as being slightly larger than the mask; however, the present invention imposes no limitation as to the size of the member for exposure  2 . 
     The first and second light sources  11 ,  12  are light sources for respectively outputting ultraviolet light, for example. Mercury lamps, xenon lamps, excimer lamps, ultraviolet LEDs, and the like, for example, are suitable for use. A collimator lens and/or a reflecting mirror or the like, for example, are disposed respectively on the optical paths of the exposure light output by the first and second light sources  11 ,  12 , so that, for example, the alignment material film on the surface of the member for exposure  2  is irradiated with a predetermined quantity of light by the first and second light sources  11 ,  12 . The output direction of the exposure light  11   a ,  12   a  can be adjusted, for example, through control of the first and second light sources  11 ,  12  by a control device (not illustrated). A constitution whereby the angle of incidence on the member for exposure  2  is adjustable is thereby achieved. In the exposure device  1  of the present embodiment, the beams of exposure light  11   a ,  12   a  from the first and second light sources  11 ,  12  are output so as to mutually intersect between the first and second light sources  11 ,  12  and the mask  13 . In the present embodiment, both of the beams of the exposure light  11   a ,  12   a  are linear-polarized exposure light that is either P-polarized or S-polarized, for example, and do not interfere with one another even in the case of intersection on the optical paths thereof. By irradiating the alignment material film with the exposure light  11   a  and the exposure light  12   a  at respectively different pre-tilt angles, the alignment directions of the liquid crystal molecules can be made to differ from one another, and, for example, the alignment direction of the alignment film can be increased to two directions for each single picture elements or each of adjacent pixels in the width direction, to increase the viewing angle of a liquid crystal display or the like. 
     As shown in  FIG. 1 ( b ) , the mask  13  is constituted, for example, by a frame  130  and a pattern formation portion  131  at the center thereof. As shown in  FIG. 2 ( a ) , in the pattern formation portion  131 , there are formed a first light transmission region group  131   a  and a second light transmission region group  131   b  in which a plurality of light transmission regions are respectively arrayed in a single row in a direction perpendicular to the scanning direction and corresponding respectively to the exposure light from the first or second light source  11 ,  12 . In the present embodiment, the first light transmission region group  131   a  and the second light transmission region group  131   b  are disposed spaced apart in the direction of relative scanning of the alignment material film with respect to the mask  13 . As shown in  FIG. 2 ( b ) , the respective plurality of light transmission regions correspond to regions that extend in the scanning direction and include a plurality of pixels lined up in the scanning direction. The light transmission regions of the first light transmission region group  131   a  and the light transmission regions of the second light transmission region group  131   b  are arrayed with intervals therebetween such that there is no overlap in the scanning direction. For example, the light transmission regions of the first light transmission region group  131   a  and the light transmission regions of the second light transmission region group  131   b  are arrayed in staggered fashion to one another along a direction perpendicular to the scanning direction, such that there is no overlap in the scanning direction. In the present embodiment, the light transmission regions of the first and second light sources  11 ,  12  are apertures of a shape for transmitting the exposure light  11   a ,  12   a , or light-transmissive members. By irradiating the respectively different regions  131   a ,  131   b  of the mask  13  with the exposure light  11   a ,  12   a  from the first and second light sources  11 ,  12  from different directions, the light transmitted through the light transmission regions irradiates and exposes the alignment material film on the surface of the member for exposure  2 , which is supported on the stage  15 . As shown in  FIG. 2 ( a ) , in the present embodiment, of the light transmission regions of the pattern formation portion  131 , the first light transmission region group  131   a  corresponding to the exposure light  11   a  output from the first light source  11  is formed to the second light source  12  side, and the second light transmission region group  131   b  corresponding to the exposure light  12   a  output from the second light source  12  is formed to the first light source  11  side. Therefore, as shown in  FIG. 2 ( c ) , in the present embodiment, the areas exposed by the exposure light  11   a  from the first light source  11  and the areas exposed by the exposure light  12   a  from the second light source  12  are situated mutually spaced apart. 
     The mask stage  14  supports the frame  130  of the mask  13 , to the first light source  11  side. In the present invention, the light source on the mask stage  14  side is termed the first light source  11 ; however, the designations “first” and “second” have no particular significance. The mask stage  14  is either affixed to another component, not illustrated, inside the exposure device, or is constituted such that the mask stage  14  can move in coincidence with the area being exposed by the exposure light. For example, the mask stage  14  is moveable in the horizontal direction, in coincidence with the angle of slope of the exposure light  11   a  and/or the exposure light  12   a  with respect to the exposure surface of the member for exposure  2 . For example, the mask stage  14  is constituted to be moveable in the vertical direction as well. 
     The stage  15  supporting the member for exposure  2  is adjustable in position through computer control, for example. By moving the stage  15  after the member for exposure  2  has been placed thereon, the area irradiated by the exposure light on the surface of the member for exposure  2  can be moved. In so doing, a plurality of areas on the member for exposure  2  can be exposed in succession. 
     As shown in  FIG. 2 , in the present embodiment, the areas on the surface of the member for exposure  2  which are irradiated by the two beams of exposure light  11   a ,  12   a  transmitted through the mask  13  are areas, corresponding to the apertures or light-transmissive members of the mask, in which a plurality of picture elements (constituted by three R, G, and B picture elements) of a liquid crystal display or the like line up in one direction (the scanning direction of the exposure device), with the areas exposed by the exposure light  11   a  from the first light source  11  and the areas exposed by the exposure light  12   a  from the second light source  12  being at positions mutually spaced apart. Consequently, while simultaneous exposure of areas of mutually adjacent pixels is not possible, unexposed adjacent pixels are exposed by the other beam of exposure light, by carrying out exposure while moving the stage  15 . Specifically, in the present embodiment, exposure of mutually adjacent pixels is carried out at staggered timing, forming an alignment film of mutually adjacent areas exposed by the exposure light  11   a  output from the first light source  11  and areas exposed by the exposure light  12   a  output from the second light source  12 . 
     As shown in  FIG. 9 , in a conventional exposure device, two beams of exposure light at different output angles irradiate mutually adjacent regions equivalent to one-half of one picture element, or pixels adjacent in the width direction, so that a single picture element, or pixels adjacent in the width direction, are respectively exposed simultaneously by two different light sources. In contrast to this, in the exposure device  1  of the present embodiment, the exposure light  11   a ,  12   a  from the first and second light sources  11 ,  12  is output in such a way that the beams intersect on the optical path between the first and second light sources  11 ,  12  and the mask  13 , and are respectively transmitted through the pattern lying towards the other light source, with the two beams of exposure light irradiating the surface of the member for exposure  2  at mutually spaced apart locations. Therefore, in the present embodiment, the distance between the first light source  11  and the second light source  12  can be shorter, and the device can be smaller overall. 
     The operation of the exposure device of the present embodiment is described next. Before initiating exposure, firstly, the member for exposure  2 , for example, a glass substrate on which an alignment material film of predetermined thickness has been formed on the top surface, is placed on the stage  15 . At this time, the position of the member for exposure  2  is adjusted, for example, so that the surface for exposure of the alignment material film on the member for exposure  2  is parallel to the top surface of the stage  15 . Moreover, the position of the member for exposure  2  is adjusted, for example, so that the zone for exposure of the alignment material film lies within the exposure region of the exposure light. In preferred practice, this adjustment of the position of the member for exposure  2  is performed after placing the member for exposure  2  on the stage  15 , through movement of the stage, which is moveable by computer control for example. In so doing, a plurality of regions can be exposed in succession on the member for exposure  2 . 
     Next, the directions in which to align the alignment material film are determined for each region that will become a pixel lined up in the scanning direction. The directions of output of exposure light from the first and second light sources  11 ,  12  are then determined in corresponding fashion with the alignment directions so determined, in such a way that the split regions will be irradiated with exposure light at predetermined angles. Next, the distance between the first light source  11  and the second light source  12  is adjusted in such a way that predetermined regions of the alignment material film formed on the member for exposure  2  can be irradiated with the exposure light, and the position of the patterns of light transmission regions of the mask  13  are adjusted through adjustment of the position of the mask stage  14 . The mask  13  is selected to coincide with the pattern to be exposed on the alignment material film. 
     In the present embodiment, the positions of the first light source  11  and the second light source  12  are adjusted such that the exposure light  11   a  output from the first light source  11  and the exposure light  12   a  output from the second exposure light  12  mutually intersect on the optical path prior to irradiating the pattern formation portion  131  of the mask  12 . Consequently, the distance between the first light source  11  and the second light source  12  can be shorter, as compared with a conventional exposure device. Therefore, irradiation by the exposure light  11   a ,  12   a  can take place over a wider range free from interference by the device itself (for example, by the mask stage  14  or the frame  130  of the mask). 
     Once the positions of the first and second light sources  11 ,  12  and the mask  13  have been determined, next, exposure light is output from the light sources. The exposure light  11   a ,  12   a  output from the light sources is transmitted or reflected by optical members, such as a collimator lens and/or mirror, or the like for example, directing a predetermined quantity of light onto the mask  13 . 
     In the present embodiment, the exposure light  11   a  output from the first light source  11  and the exposure light  12   a  output from the second light source  12  mutually intersect on the optical path leading to the pattern formation portion  131 . However, the exposure light  11   a ,  12   a  is directed onto the alignment material film in a manner free of mutual interference between them. Because the two beams of exposure light  11   a ,  12   a  are made to mutually intersect, even when the angle of slope of the exposure light  11   a ,  12   a  with respect to surface for exposure is small, the exposure light  11   a ,  12   a  is directed onto the predetermined light exposure regions  131   a ,  131   b  of the mask  13  in a manner free of interference with the mask stage or the like. When the exposure light  11   a ,  12   a  irradiates the respective corresponding light exposure regions  131   a ,  131   b  of the pattern formation portion  131 , the exposure light  11   a ,  12   a  is transmitted through the mask  13  in a manner corresponding to the pattern of light transmission regions of the pattern formation portion  131 , and the light transmitted through the mask is directed onto the member for exposure  2 . 
     The exposure light  11   a  and the exposure light  12   a  irradiate regions mutually spaced apart on the alignment material film. In the present embodiment, the regions irradiated through the light transmission regions of the mask  13  by the exposure light  11   a  and the exposure light  12   a  are, for example, a plurality of regions corresponding to pixels (constituted by three R, G, B picture elements) of a liquid crystal display or the like, which line up in one direction (the scanning direction in the exposure device), with the regions that will constitute the plurality of pixels lined up in the scanning direction being respectively exposed through the respective plurality of light transmission regions that have been formed in the pattern formation portion  131  of the mask  13  (and that line up in the width direction perpendicular to the scanning direction). In the regions irradiated by the exposure light  11   a  and the exposure light  12   a , the alignment material film, due to its photodegradation characteristic, aligns in predetermined directions corresponding to the angle of irradiation by the exposure light. Therefore, the alignment material film, in the regions thereof irradiated by the exposure light  11   a , aligns in a first direction dependent on the angle of incidence of the exposure light  11   a , while the alignment material film, in the regions thereof irradiated by the exposure light  12   a , aligns in another second direction different from the first direction and dependent on the angle of incidence of the exposure light  12   a . In so doing, for the plurality of pixels lined up in the scanning direction, alignment film aligned in the first direction, and alignment film aligned in the second direction, is formed so as to extend in a band in the scanning direction. In the present embodiment, the exposure light  11   a ,  12   a  irradiating the alignment material film can expose the alignment material film in the normal manner free from interference by the device itself on the optical path. 
     In a state of continued irradiation by the exposure light  11   a ,  12   a  in this manner, by moving the stage  15  through computer control, and moving the member for exposure  2  at a constant speed along the scanning direction for example, the member for exposure  2  is continuously exposed through continuous irradiation by the exposure light  11   a ,  12   a . In so doing, adjacent pixels unexposed by one exposure light are ultimately exposed by the other exposure light, forming an alignment film of mutually adjacent exposed regions produced by the exposure light  11   a  of the first light source  11  and exposed regions produced by the exposure light  12   a  of the second light source  12 . 
     Once all of the regions for exposure on the member for exposure  2  have been exposed, the member for exposure  2  is ejected from the exposure device  1 , for example, by moving the stage  15 . In this way, there may be manufactured, on a glass substrate for example, an alignment film in which regions of band shape of uniform alignment direction are formed to correspond to pixels lined up in the scanning direction, with the alignment directions differing between adjacent pixels in a direction perpendicular to the scanning direction. Liquid crystals are then sandwiched between the alignment films of two glass substrates manufactured in this manner. Thereupon, the calamitic molecules of the liquid crystals orient in a predetermined direction due to the alignment direction of the alignment films. In so doing, a multidomain alignment system liquid crystal display material affording a wide viewing angle is perfected. Polarized films, such as those for a 3D display, can also be manufactured by the method for forming an alignment film as in the present embodiment. Specifically, by irradiating individual regions to constitute adjacent pixels in the width direction of the film for example, by exposure light from two light sources, doing so with exposure light of linear-polarized light, namely, P-polarized light and S-polarized light in alternating fashion, the alignment direction of the alignment material film can be varied in each of the pixels constituted by a plurality of picture elements. In so doing, there can be obtained an alignment film having a function comparable to a ¼λ panel in which the alignment directions at the film surface mutually differ by 90°, and the resulting film can be used as a polarized film. Specifically, by causing light for image display, which is linear-polarized light, to be transmitted through the polarized film, each of display rows constituted by a plurality of pixels and extending in the width direction of the film can be made to output transmitted light which is circular-polarized light of mutually opposite rotation directions. These two beams of transmitted light of circular-polarized light can be used respectively as display light for the right eye and the left eye in a 3D display, for example. 
     In the above manner, in the exposure device  1  of the present embodiment, the exposure light  11   a ,  12   a  is output in such a way as to mutually intersect on the optical path between the first and second light sources  11 ,  12  and the mask  13 , and therefore the distance between the first light source  11  and the second light source  12  can be smaller, and the alignment material film can be exposed in the normal manner, even when the angle of the exposure light  11   a ,  12   a  with respect to the surface for exposure is small. 
     As shown in  FIG. 2 ( b ) , in the present embodiment, the light transmission regions of the first and second light transmission region groups  131   a ,  131   b  of the mask  13  respectively correspond to regions that include a plurality of pixels lined up in the scanning direction; however, this represents a case in which an alignment film of uniform alignment direction extending in the scanning direction is formed by continuous exposure to exposure light. The present invention is not limited to this mode, and can be applied in a case in which a member for exposure is exposed through intermittent irradiation by exposure light as well. Specifically, as shown in  FIG. 4 ( a )  and  FIG. 4 ( b )  for example, the light transmission regions of the first and second light transmission region groups  131   a ,  131   b  can be split into a plurality of regions in the scanning direction (in  FIG. 4 ( b ) , six), with each of these light transmission regions corresponding to a region equivalent to a single picture element split in two in the width direction perpendicular to the scanning direction. In so doing, regions corresponding to a plurality of picture elements can be exposed through a single exposure cycle. The member for exposure  2  is then moved, for example by the stage  15 , at a constant speed on the horizontal along the scanning direction, for example, towards the first light source  11  side or the second light source side  12 , while performing exposure through irradiation with exposure light, each time that it has moved by a distance of movement equal to the length of the pattern in the scanning direction (in the present modification, a length equivalent to six picture elements (see  FIG. 4 )). In this case, however, it is preferable that the regions irradiated on the surface of the member for exposure  2  by the two beams of exposure light be spaced apart, for example, by an integral multiple of the picture element length. Specifically, as shown in  FIG. 4 ( c ) , in the present modification as well, the regions exposed by the first light source  11  and the regions exposed by the second light source  12  are mutually spaced apart; and by adopting an integral multiple of the picture element length as the distance therebetween, in picture elements in which a region equivalent to one-half thereof has already been exposed by one of the light sources, the region equivalent to the other half can be exposed by the other light source, in accurately matching fashion. In so doing, there is manufactured a film in which a plurality of regions equivalent to single picture elements split into two, and in which the alignment film in each split region of the regions is respectively formed with a different alignment direction, are lined up in a matrix arrangement. 
     In the present embodiment, the configuration is such that the stage  15  is moveable along the scanning direction by computer control; however, in the exposure device of the present invention, there is no limitation to the mode of the present embodiment, and the direction in which the stage  15  is moved can be controlled by computer as well, for example. Specifically, in case in which stepped exposure is performed, as in the aforedescribed modification for example, the direction in which the stage  15  is moved can be controlled in such a way that, after completing formation of the alignment film in a first zone for exposure, the regions in which the pattern has been formed are moved in the width direction, which is the direction in which the picture elements are split, for example. In so doing, zones for exposure situated adjacently in the width direction of the picture elements are exposed in succession. Moreover, even in cases in which, for example, the disposition of the zones for exposure in the member for exposure  2  is not such that they are mutually adjacent (continuous), by moving the stage  15  and disposing the zones for exposure in regions irradiated by the exposure light, the zones for exposure can undergo stepped exposure in succession. 
     Next, an exposure device according to a second embodiment of the present invention is described.  FIG. 5 ( a )  is a side view showing multidomain alignment exposure by an exposure device according to a second embodiment of the invention, and ( b ) is a perspective view thereof.  FIG. 6  is a schematic diagram showing the relationship of the mask and the exposure light in the exposure device according to the second embodiment of the invention. 
     The first embodiment was constituted such that the exposure light  11   a ,  12   a  outputted by the first and second light sources  11 ,  12  intersect between the first and second light sources  11 ,  12  and the mask  13 . In the present embodiment, however, intersection position of the two beams of exposure light  11   a ,  12   a  output by the first and second light sources  11 ,  12  is between the mask  13  and the alignment material film, as shown in  FIGS. 5 and 6 . 
     Moreover, the positions of the mask  13  and the mask stage  14  are further away from the member for exposure  2 , as compared with the first embodiment. The constitution is otherwise comparable to the first embodiment. 
     In the present embodiment, because the exposure light  11   a ,  12   a  mutually intersects between the mask  13  and the alignment material film, as shown in  FIG. 5 , the distance between the first light source  11  and the second light source  12  must be slightly greater than in the case of the first embodiment, but the device overall can still be smaller in size than in the past. 
     Moreover, the range in which irradiation by the exposure light  11   a ,  12   a  can take place free from interference by the device itself (for example, by the mask stage  14  or the frame  130  of the mask) is wider than in a conventional exposure device, and even when the angle of slope of the exposure light  11   a ,  12   a  with respect to the surface for exposure is small, the alignment material film can be irradiated by the exposure light  11   a ,  12   a  free from interference by the mask stage or the like, and the alignment material film can be exposed in the normal manner. 
     In the present embodiment, as in the first embodiment, the light transmission regions of the first and second light transmission region groups  131   a ,  131   b  are constituted so as to extend in the scanning direction as shown in  FIG. 2 ( a )  and  FIG. 2 ( b )  for example; and by causing the exposure light to be continuously transmitted through the light transmission regions while moving the member for exposure  2  at constant speed along the scanning direction, for example, the member for exposure  2  may be continuously irradiated and exposed by the exposure light, to obtain an oriented film of uniform alignment direction in regions of band shape along the scanning direction, whereby a polarized film for use in a 3D display, for example, can be manufactured. In this case as well, because there is no need for the exposure regions having been split into two and constituting picture elements to be adjacent, there is no limitation as to the distance in the scanning direction between the regions irradiated by the two beams of exposure light. 
     Regions irradiated by the exposure light  11   a  from the first light source  11  and regions irradiated by the exposure light  12   a  from the second light source  12  are positioned mutually spaced apart on the surface of the member for exposure  2  as shown in  FIG. 6 . In a case in which exposure regions that correspond to a plurality of picture elements are exposed each time that regions are irradiated with the exposure light while intermittently outputting exposure light, the distance between these irradiated regions may be set to an integral multiple of the length of a single picture element, for example, as in the first embodiment. In so doing, as in the case of the modification of the first embodiment, after exposure has been completed in the state shown in  FIG. 6 , by then, for example by moving the stage  15  to move the member for exposure  2  at a constant speed while irradiating the member for exposure with exposure light each time that it has moved by the equivalent of the length of the pattern in the scanning direction (in the case of use of the mask  13  like that shown in  FIG. 4 , a length equivalent to six picture elements), there can be obtained an alignment film in which the areas exposed by the exposure light  11   a  and the areas exposed by the exposure light  12   a  are adjacent, with regions equivalent to one-half a single pixel element being aligned in respectively different directions. Specifically, in the present embodiment as well, regions equivalent to a single picture element split into two are exposed at staggered timing. In so doing, there is manufactured a film in which a plurality of regions equivalent to single picture elements split into two, and in which the alignment film in each split region of the regions is respectively formed with a different alignment direction, are lined up in a matrix arrangement. 
     An exposure device according to a third embodiment of the present invention is described next.  FIG. 7 ( a )  is a side view showing multidomain alignment exposure by an exposure device according to a third embodiment of the invention, and ( b ) is a perspective view thereof.  FIG. 8  is a plan view showing the mask in the exposure device according to a third embodiment of the invention. 
     As shown in  FIG. 7 , in the present embodiment, the mask  13  in the first embodiment has been split into a first mask  13   a  for transmission of the exposure light  11   a  from the first light source  11 , and a second mask  13   b  for transmission of the exposure light  12   a  from the second light source  12 . Consequently, as shown in  FIG. 7 ( b )  and  FIG. 8 , the first light transmission region group  131   a  for transmission of the exposure light  11   a  from the first light source  11  is furnished to the first mask  13   a , while the second light transmission region group  131   b  for transmission of the exposure light  12   a  from the second light source  12  is furnished to the second mask  13   b . As in the first and second embodiments, the first and second light transmission region groups  131   a ,  131   b  are respectively disposed in a single row so as to line up in a direction perpendicular to the scanning direction. The respective plurality of light transmission regions extend in the scanning direction, and correspond to regions that include a plurality of pixels lined up in the scanning direction. The first mask  13   a  and the second mask  13   b  are respectively supported on mask stages  14 , and are thereby constituted such that the first mask  13   a  and the second mask  13   b  are respectively moveable independently. Specifically, in the present embodiment, as shown in  FIG. 7 , the mask stage  14  that supports the first mask  13   a  is disposed on the second light source  12  side, while the mask stage  14  that supports the second mask  13   b  is disposed on the first light source  11  side. The constitution is otherwise comparable to the first embodiment. 
     In the present embodiment, as in the exposure device of the first embodiment, the distance between the first light source  11  and the second light source  12  can be smaller, the device can be made more compact in size overall, and the range in which irradiation by the exposure light  11   a ,  12   a  can take place free from interference by the device itself (for example, by the mask stages  14  or the frame  130  of the mask) is wider; moreover, even when the angle of slope of the exposure light  11   a ,  12   a  with respect to the surface for exposure is small, the alignment material film can be exposed in the normal manner. Furthermore, in the present embodiment, the mask  13  has been split into the first mask  13   a  and the second mask  13   b  which are respectively supported by the mask stages  14  so as to be moveable independently, whereby the position of the mask, the quantity of the exposure light irradiating the member for exposure  2 , and other variables can be adjusted for each light source. Consequently, in a case in which, for example, the exposure light from one of the light sources fails to irradiate a predetermined quantity of light onto the member for exposure  2 , the mask  13   a  or the mask  13   b  for transmitting the target exposure light can be moved by the mask stage  14  to adjust the position or quantity of the exposure light. 
     In the present embodiment, as in the first and second embodiments, the light transmission regions of the first and second light transmission region groups  131   a ,  131   b  are constituted so as to extend in the scanning direction as shown in  FIG. 2 ( a )  and  FIG. 2  ( b ) for example; and by causing the exposure light to be continuously transmitted through the light transmission regions while moving the member for exposure  2  at constant speed along the scanning direction, for example, the member for exposure  2  may be continuously irradiated and exposed by the exposure light, to obtain an oriented film of uniform alignment direction in regions of band shape along the scanning direction, whereby a polarized film for use in a 3D display, for example, can be manufactured. 
     In the present embodiment as well, as shown, for example, in  FIG. 4 ( a )  and  FIG. 4 ( b ) , stepped exposure may be performed while splitting the light transmission regions of the first and second light transmission regions light transmission region groups  131   a ,  131   b  into a plurality of regions along the scanning direction, with each light transmission region corresponding to a region equivalent to one picture element split into two in the width direction perpendicular to the scanning direction; and a film in which a plurality of regions equivalent to single picture elements split into two, and in which the alignment film in each split region of the regions is respectively formed with a different alignment direction, are lined up in a matrix arrangement, can be manufactured. 
     INDUSTRIAL APPLICABILITY 
     The exposure device of the present invention photoaligns an alignment material film by splitting portions of the alignment material film which correspond to picture elements of a liquid crystal display device into two parts, and exposing these from different directions; or by exposing portions which correspond to pixels from a different direction in each adjacent pixel in the width direction thereof. In this way, with the exposure device of the present invention, during manufacture of an alignment material film for a liquid crystal display device displaying three-dimensional images, the alignment material film can undergo multidomain exposure in a predetermined pattern in the normal manner. 
     KEY 
     
         
         
           
               1  Exposure device 
               11  First light source 
               12  Second light source 
               11   a  Exposure light (from first light source) 
               12   a  Exposure light (from second light source) 
               13  Mask 
               13   a  First mask 
               13   b  Second mask 
               130  Frame 
               131  Pattern formation portion 
               131   a  First light transmission region group 
               131   b  Second light transmission region group 
               14  Mask stage 
               15  Stage 
               2  Member for exposure