JP2013142727A - Optical film manufacturing device, optical film manufacturing method, and optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a known method for forming patterns on a film by applying an optical orientation resin on the film and exposing the film through a photomask, in which if the exposure is performed in a roll-to-roll method during transferring a long film, the border of alignment patterns is not formed clearly.SOLUTION: An optical film manufacturing device manufactures an optical film having a plurality of alignment regions during transferring a long film continuously. The optical film manufacturing device comprises support rolls supporting the film and exposure parts that are opposed to the support rolls and that develop a plurality of alignment regions, in an optical orientation resin, of which alignment regions are different from each other in molecular alignment direction by exposing the optical orientation resin on the film through a mask with polarized light. The support rolls each have a suppressing part that suppresses the reflection of the exposure light.

Description

  The present invention relates to an optical film manufacturing apparatus, an optical film manufacturing method, and an optical film.

2. Description of the Related Art Conventionally, a technique is known in which a resist is applied to a long film and exposed through a photomask while the film is supported by a plurality of rollers to form a pattern on the film (for example, Patent Document 1). ). Further, in order to accurately form a groove (scribe) for dividing a thin film layer provided in a solar cell or the like, a dielectric layer that transmits or attenuates laser light and a light absorption layer that absorbs laser light are used. A technique for forming a groove in a thin film layer using a substrate supporting means having a heavy structure is known (for example, Patent Document 2).
[Patent Literature]
[Patent Document 1] Japanese Patent Application Laid-Open No. 4-97155 [Patent Document 2] Japanese Patent Application Laid-Open No. 10-27918

  However, according to the method of Patent Document 1, since the exposure is performed on the region located between the rollers in the film, the exposed film may be wrinkled. Therefore, it is conceivable to expose the film on a roller. In this case, however, there is a problem that the boundary of the alignment pattern cannot be clearly formed because unnecessary reflected light from the roller re-enters the film. Moreover, the method of patent document 2 is a method of forming the groove | channel for dividing | segmenting thin film layers, such as a solar cell, accurately, and has an optical film which has a different orientation pattern and the boundary of the orientation pattern was formed clearly. It cannot be manufactured.

  1st aspect of this invention is an optical film manufacturing apparatus which manufactures the optical film which has a some orientation area | region, conveying a elongate film continuously, Comprising: Photoalignment resin was apply | coated. A support roll for supporting the film and a plurality of alignment regions arranged opposite to the support roll and having different alignment directions of molecules in the photo-alignment resin by exposing the photo-alignment resin of the film with polarized light through a mask The support roll provides an optical film manufacturing apparatus having a roll body and a suppressing section for suppressing reflection of exposure on the roll body.

  In the second aspect of the present invention, a coating step in which the photo-alignment resin is applied to a long film and dried, and while the film is continuously conveyed in the longitudinal direction, the photo-alignment resin is interposed through a mask. Exposure step of exposing the photo-alignment resin to a plurality of alignment regions having different molecular orientation directions by exposing with polarized light. It is a stage which exposes, and a support roll provides the manufacturing method of an optical film provided with the suppression part which is provided in the surface of a roll main body and a roll main body, and suppresses reflection of exposure.

  In the third aspect of the present invention, an alignment layer formed of a photo-alignment resin and having a plurality of alignment regions having different alignment directions of molecules, a transparent substrate that supports the alignment layer, and a pre-alignment layer Is provided on the substrate side, and an optical film comprising a light absorption layer that absorbs light having a wavelength for curing the photo-alignment resin is provided.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

The structure of the optical film 10 in 1st Embodiment is shown. The disassembled perspective view of the three-dimensional display apparatus 1000 provided with the optical film 10 is shown. The whole structure of the optical film manufacturing apparatus 100 in this embodiment is shown. The structure of the orientation process part 116 in this embodiment is shown. The top view of the mask 138 in this embodiment is shown. The cross-sectional schematic diagram of the exposure part of the orientation processing part 116 in this embodiment is shown. The expanded sectional view of the support roll 130 in this embodiment is shown. The expanded sectional view of the support roll 130 in the 1st modification of this embodiment is shown. The expanded sectional view of the support roll 130 in the 2nd modification of this embodiment is shown. The manufacturing method of the optical film 10 in this embodiment is shown. The manufacturing method of the optical film 10 in this embodiment is shown. The photograph which observed the orientation pattern of the liquid crystal layer 40 of the optical film 10 by crossed Nicols is shown. The structure of the optical film 12 in the 3rd modification of this embodiment is shown. The structure of the optical film 14 in the 4th modification of this embodiment is shown. The photograph which observed the boundary of the orientation pattern of the liquid crystal layer 40 of the optical film obtained in Comparative Example 8 with crossed Nicols is shown. The photograph which observed the boundary of the orientation pattern of the liquid crystal layer 40 of the optical film obtained in Example 10 by crossed Nicols is shown.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows a configuration of an optical film 10 in the first embodiment. The optical film 10 is provided, for example, on the image light emission side of the stereoscopic display device. An example of the optical film 10 is a retardation film, which converts incident image light into a left-eye polarization image and a right-eye polarization image and outputs the converted image light.

  The optical film 10 includes a base material 20, an alignment layer 30, and a liquid crystal layer 40. The substrate 20 is a long film that supports the alignment layer 30. The substrate 20 is preferably at least transparent to visible light and optically isotropic. The base material 20 is, for example, a cycloolefin polymer (COP) film or a triacetyl cellulose (TAC) film.

  The alignment layer 30 is a photo-alignment resin that is laminated on the surface of the substrate 20 and cured. The alignment layer 30 may be, for example, a film obtained by aligning and curing photo-alignable resin molecules such as a photolytic type, a photodimer type, or a photoisomer type in a predetermined direction with linearly polarized ultraviolet rays. The alignment layer 30 includes a plurality of alignment regions 32 and 34 having different molecular alignment directions. In the example shown in FIG. 1, the alignment layer 30 has a pattern in which striped alignment regions 32 and 34 extending in the Y direction are repeatedly arranged in the X direction.

  The liquid crystal layer 40 is a liquid crystal compound stacked on the surface of the alignment layer 30. The liquid crystal layer 40 is made of, for example, a nematic liquid crystal compound. The polymer of the liquid crystal compound contained in the liquid crystal layer 40 is aligned along the alignment direction of the alignment regions 32 and 34 of the alignment layer 30. Thereby, the liquid crystal layer 40 has a plurality of alignment regions 42 and 44 in which the alignment directions of the polymers are different from each other. In the example shown in FIG. 1, the liquid crystal layer 40 has a pattern in which striped alignment regions 42 and 44 extending in the Y direction are repeatedly arranged in the X direction. The alignment direction 50 of the alignment region 42 and the alignment direction 60 of the alignment region 44 are orthogonal to each other in the XY plane. The optical film 10 having such a configuration functions as, for example, a quarter wavelength plate.

  FIG. 2 is an exploded perspective view of the stereoscopic display device 1000 including the optical film 10. The stereoscopic display device 1000 includes a light source 1200, an image display unit 1300, and the optical film 10 in this order. The image display unit 1300 includes a light source side polarizing plate 1500, an image generation unit 1600, and an emission side polarizing plate 1700. When an observer observes a stereoscopic image displayed by the stereoscopic display device 1000, the observer observes from the right side of the optical film 10 in FIG.

  The light source 1200 is arranged on the farthest side of the stereoscopic display device 1000 as viewed from the observer, and is white in a state where the stereoscopic display device 1000 is used (hereinafter abbreviated as “usage state of the stereoscopic display device 1000”). The non-polarized light is emitted toward one surface of the light source side polarizing plate 1500.

  The light source side polarizing plate 1500 is disposed on the light source 1200 side in the image generation unit 1600. When the non-polarized light emitted from the light source 1200 is incident, the light source-side polarizing plate 1500 transmits linearly polarized light having a polarization direction parallel to the transmission axis direction of the non-polarized light and linearly polarized light having a polarization direction parallel to the absorption axis direction. Shut off. The direction of the transmission axis in the light source side polarizing plate 1500 is 45 degrees from the horizontal direction when the observer looks at the stereoscopic display device 1000 as indicated by an arrow in FIG.

  The image generation unit 1600 includes a right eye image generation area 1620 and a left eye image generation area 1640. As shown in FIG. 2, the right eye image generation area 1620 and the left eye image generation area 1640 are areas obtained by dividing the image generation unit 1600 in the horizontal direction, and a plurality of right eye image generation areas 1620 and left eye image generation areas 1640 are vertical. Staggered in the direction.

  In the usage state of the stereoscopic display device 1000, a right-eye image and a left-eye image are generated in the right-eye image generation region 1620 and the left-eye image generation region 1640 of the image generation unit 1600, respectively. At this time, when the light transmitted through the light source side polarizing plate 1500 enters the right eye image generation region 1620 of the image generation unit 1600, the transmitted light of the right eye image generation region 1620 is the image light of the right eye image (hereinafter referred to as “right eye image light”). For short). Similarly, when the light transmitted through the light source side polarizing plate 1500 enters the left eye image generation region 1640 of the image generation unit 1600, the transmitted light of the left eye image generation region 1640 is the image light of the left eye image (hereinafter, “left eye image light”). For short).

  Note that the right-eye image light transmitted through the right-eye image generation region 1620 and the left-eye image light transmitted through the left-eye image generation region 1640 are, for example, straight lines having the same polarization direction as the transmission axis in the output-side polarizing plate 1700 described later. Become polarized. In such an image generation unit 1600, for example, an LCD (liquid crystal display) in which a plurality of small cells are arranged two-dimensionally in the horizontal direction and the vertical direction, and liquid crystal is sealed between alignment films in each cell.

  The exit side polarizing plate 1700 is disposed on the viewer side in the image generation unit 1600. When the right-eye image light that has been transmitted through the right-eye image generation region 1620 and the left-eye image light that has been transmitted through the left-eye image generation region 1640 are incident on the output-side polarizing plate 1700, the polarization direction of these light beams is the transmission axis. Transmits parallel linearly polarized light and blocks linearly polarized light whose polarization direction is parallel to the absorption axis. Here, the direction of the transmission axis in the exit-side polarizing plate 1700 is 45 degrees from the horizontal direction when the observer looks at the stereoscopic display device 1000 as indicated by an arrow in FIG.

  The optical film 10 is arranged on the viewer side with respect to the emission side polarizing plate 1700. The optical film 10 has an alignment region 42 and an alignment region 44 having an alignment direction represented by arrows, and functions as a quarter wavelength plate. The positions and sizes of the alignment region 42 and the alignment region 44 in the optical film 10 correspond to the positions and sizes of the right eye image generation region 1620 and the left eye image generation region 1640 of the image generation unit 1600, as shown in FIG. ing. Therefore, in the usage state of the stereoscopic display device 1000, the right-eye image light transmitted through the right-eye image generation region 1620 is incident on the right-eye alignment region 42, and the left-eye image is input to the left-eye alignment region 44. Left-eye image light that has passed through the generation region 1640 enters.

  The alignment region 42 converts the incident right-eye image light into right-handed circularly polarized light and transmits it. The alignment region 44 converts the incident left eye image light into counterclockwise circularly polarized light and transmits it. Therefore, the rotation direction of the circular polarization of the right-eye image light transmitted through the alignment region 42 is opposite to the rotation direction of the circular polarization of the left-eye image light transmitted through the alignment region 44.

  The left eye filter and right eye filter of the polarized glasses worn by the observer selectively transmit circularly polarized light having different rotation directions. And the observer can visually recognize a stereo image by observing the image which passed each filter with the left eye and the right eye.

  FIG. 3 shows the overall configuration of the optical film manufacturing apparatus 100 in the present embodiment. The optical film manufacturing apparatus 100 performs a plurality of processes such as coating, drying, and exposure while continuously transporting a long film in the direction of the arrow in a continuous manner, that is, while transporting by a so-called roll-to-roll method. The optical film 10 having the alignment region is manufactured. In the following description, “upstream side” means a side opposite to the film transport direction, and “downstream side” means the same side as the film transport direction. 3 includes a supply unit 108, a winding unit 126, an alignment layer coating unit 112, an alignment layer drying unit 114, an alignment processing unit 116, a liquid crystal layer coating unit 120, a liquid crystal layer drying unit 122, And a liquid crystal layer curing unit 124.

  The supply unit 108 is disposed on the most upstream side in the transport direction of the optical film 10 and supplies the base material 20 that serves as a support for the optical film 10. An example of the supply unit 108 is a delivery roll. In this case, the base material 20 is previously wound around the outer periphery of the delivery roll, and the base material 20 is unwound by rotating the delivery roll.

  The alignment layer coating unit 112 is disposed on the downstream side of the supply unit 108 and applies the photo-alignment resin 28 on one surface of the substrate 20. The alignment layer coating unit 112 may be any coating device that can coat the film being conveyed, and is, for example, a die coater, a micro gravure coater, or a roll coater.

  The alignment layer drying unit 114 is disposed on the downstream side of the alignment layer coating unit 112 and dries the photo-alignment resin 28 applied to the substrate 20. The alignment layer drying unit 114 is, for example, a drying device such as an oven or a blower that can dry the film being transported.

  The alignment processing unit 116 is disposed on the downstream side of the alignment layer drying unit 114, and exposes the dried photo-alignment resin 28 with linearly polarized ultraviolet rays while continuously transporting the substrate 20 in the longitudinal direction. Thereby, the alignment process part 116 forms the alignment layer 30 which has a predetermined alignment pattern.

  The liquid crystal layer coating unit 120 is disposed on the downstream side of the alignment processing unit 116 and applies the liquid crystal compound 38 on the surface of the alignment layer 30. The liquid crystal layer coating unit 120 may be any coating apparatus that can coat the film being conveyed, and is, for example, a die coater, a micro gravure coater, or a roll coater.

  The liquid crystal layer drying unit 122 is disposed on the downstream side of the liquid crystal layer coating unit 120 and dries the liquid crystal compound 38 applied to the alignment layer 30. The liquid crystal layer drying unit 122 is, for example, a drying device such as an oven or a blower that can dry the film being conveyed.

  The liquid crystal layer curing unit 124 is disposed on the downstream side of the liquid crystal layer drying unit 122 and is cured by irradiating the dried liquid crystal compound 38 with ultraviolet rays. As a result, the liquid crystal layer curing unit 124 forms the liquid crystal layer 40 aligned along the alignment layer 30. When the liquid crystal compound is thermosetting, the liquid crystal layer curing unit 124 may be a heating device such as an oven.

  The winding unit 126 is disposed on the most downstream side of the optical film manufacturing apparatus 100 and winds up the optical film 10 manufactured through each upstream stage. The winding unit 126 is, for example, a winding roll. When the winding unit 126 rotates, the optical film 10 is wound around the outer periphery of the winding unit 126.

  The supply unit 108 and the winding unit 126 rotate in synchronism, and at least one of them has a rotation driving device such as a motor. When either one of the rolls has a rotation driving device, the roll having the rotation driving device mainly drives the conveyance of the film, and the roll without the rotation driving device rotates following the roll having the rotation driving device. When both rolls have a rotation drive device, the supply unit 108 and the winding unit 126 synchronize the feeding speed and the winding speed to stabilize the film conveyance. Alternatively, the supply unit 108 and the winding unit 126 may rotate at independent rotation speeds without being synchronized. Moreover, the optical film manufacturing apparatus 100 may have a film driving device such as another roll with a motor in the film transport path.

  FIG. 4 shows a configuration of the alignment processing unit 116 in the present embodiment. The alignment processing unit 116 exposes the photo-alignment resin 28 applied to the base material 20 continuously supplied in the arrow direction. The alignment processing unit 116 includes a support roll 130, a transport roll 132, an exposure unit 134, an exposure unit 136, and a mask 138.

  The support roll 130 is rotatable and is supplied by the supply unit 108 to support the base material 20 on which the photo-alignment resin 28 is provided. The support roll 130 applies tension to the film by bending the film conveyance path along the surface thereof. As a result, the support roll 130 prevents the film from being displaced in the width direction, and prevents wrinkles and the like from being generated in a region where the film is in contact. Moreover, the support roll 130 also suppresses that wrinkles are generated on the film between the rolls.

  The transport roll 132 is rotatable and supports the base material 20 from the alignment layer drying unit 114 and transports it to the support roll 130. Further, the transport roll 132 transports the base material 20 to the liquid crystal layer coating unit 120.

  The exposure units 134 and 136 are arranged to face the support roll 130. The exposure units 134 and 136 output linearly polarized light having different polarization directions and expose the photo-alignment resin on the substrate 20 through the mask 138, thereby expressing a plurality of alignment regions having different alignment directions. .

  The mask 138 is disposed between the exposure unit 134 and the exposure unit 136 and the substrate 20. The mask 138 shields a part of polarized light from the exposure unit 134 and the exposure unit 136 and transmits a part thereof.

  FIG. 5 shows a plan view of the mask 138 in the present embodiment. An arrow 148 indicates the film transport direction during exposure, and an arrow 149 indicates the width direction of the long film. The mask 138 is provided with a first exposure region 140 provided with a plurality of openings 142 and a second exposure region 144 provided with a plurality of openings 146. Linearly polarized light output from the exposure unit 134 is incident on the first exposure region 140, and linearly polarized light output from the exposure unit 136 is incident on the second exposure region 144.

  The opening 142 corresponds to the alignment region 34 of the alignment layer 30 and has the same size as the width of the alignment region 34 in the width direction of the film. The opening 146 corresponds to the alignment region 32 of the alignment layer 30 and has the same size as the width of the alignment region 32 in the film width direction. The openings 146 are arranged so as to be separated from the openings 142 in the film conveyance direction and between the openings 142 in the film width direction. Moreover, the opening 142 and the opening 146 transmit linearly polarized light having different polarization directions as indicated by arrows in the opening. Thereby, the alignment processing part 116 in this embodiment can form the alignment layer 30 in which the stripe-shaped alignment regions 32 and 34 are arranged without a gap.

  FIG. 6 is a schematic cross-sectional view of an exposed portion of the alignment processing unit 116 in the present embodiment. FIG. 6 corresponds to a portion A surrounded by a broken line in FIG. The arrow indicates the irradiation direction of the exposure 154 that passes through the mask 138. The support roll 130 includes a roll main body 150 and a suppressing portion 152 provided on the surface of the roll main body 150.

  The roll body 150 is a cylindrical roll, and is formed of a metal such as stainless steel, for example. The suppression unit 152 is formed on the outer periphery of the roll body 150 and suppresses reflection of the incident exposure 154.

  As shown in FIG. 6, the exposure unit 136 exposes an area of the base material 20 coated with the photo-alignment resin 28 to which the support roll 130 is in contact. Thereby, since the film is exposed in a state of being stretched in the width direction, the alignment processing unit 116 of the present embodiment can prevent the film from being wrinkled.

  In FIG. 7, the expanded sectional view of the support roll 130 in this embodiment is shown. FIG. 7 corresponds to a portion B surrounded by a broken line in FIG. In this embodiment, the suppression unit 152 is an exposure absorption layer provided on the surface of the roll body 150. The exposure absorption layer absorbs the exposure 154, thereby suppressing reflection of the exposure 154 on the surface of the support roll 130.

  An exposure absorption layer is a layer which consists of black paints, for example. The layer made of black paint is formed by, for example, applying, spraying, baking, or vapor-depositing black paint on the surface of the support roll 130. The black paint may be a paint in which a black pigment or the like is dispersed. The black paint may be formed on the outer periphery of the roll main body 150 with a uniform film thickness, thereby preventing the base material 20 from being slipped during conveyance. In addition, the suppression unit 152 may further include a resin or the like for preventing wear on the outer periphery of the black paint, thereby preventing the black paint from being worn. Alternatively, the exposure absorption layer may be a layer made of a colored or colorless ultraviolet absorbing resin or the like.

  Thereby, the suppressing part 152 can prevent the phenomenon where the photo-alignment resin 28 is aligned by the reflected light of the exposure 154 and the boundary of the alignment pattern of the alignment layer 30 becomes unclear. As a result, the alignment processing unit 116 of the present embodiment can obtain the alignment layer 30 having a clear alignment pattern boundary.

  Furthermore, since the boundary of the alignment pattern of the alignment layer 30 is clear, the boundary of the alignment pattern of the liquid crystal layer 40 formed on the surface of the alignment layer 30 is also clear. As a result, the optical film 10 manufactured by the optical film manufacturing apparatus 100 can display a high-quality stereoscopic image with little crosstalk between left and right parallax images when provided in the stereoscopic display device. In order to sufficiently obtain such an effect, it is preferable that the reflectance of the support roll 130 with respect to the ultraviolet light is 5% or less.

  The instrument used for the reflectance measurement is a spectrophotometer U-4100 (manufactured by Hitachi High-Technologies). The wavelength light used in the measurement is wavelength light that the photo-alignment resin is exposed to, and the reflectance at an incident angle of 5 degrees was measured. Here, the reflectance is the reflectance (relative reflectance) of the measurement sample with respect to the reference sample plate. This was made into the reflectance with respect to the ultraviolet-ray of the support roll 130. FIG. As the reference sample plate, a plate made of barium sulfate was used, but a plate made of another material may be used. The measurement sample was a glass plate provided with a light absorption layer provided on a support roll. In this measurement, in order to obtain the reflectance in the ultraviolet region, the measurement was performed with a high-sensitivity integrating sphere attached to the spectrophotometer.

  In FIG. 8, the expanded sectional view of the support roll 130 in the 1st modification of this embodiment is shown. FIG. 8 corresponds to part B surrounded by a broken line in FIG. In this modification, the suppression unit 152 is an exposure interference layer provided on the surface of the roll body 150. The exposure interference layer interferes so as to weaken the exposure 154 reflected at the interface, thereby suppressing the reflection of the exposure 154 on the surface of the support roll 130.

  The exposure interference layer is, for example, a metal oxide multilayer film in which the thickness of each layer is 1/4 of the exposure wavelength. Alternatively, the exposure interference layer may be a single-layer metal oxide film, a single-layer or multilayer resin film, or the like. The exposure interference layer may be formed on the outer periphery of the roll body 150 with a uniform film thickness, thereby reliably suppressing the reflection of the exposure 154 and preventing the base material 20 from being slipped during conveyance.

  In FIG. 9, the expanded sectional view of the support roll 130 in the 2nd modification of this embodiment is shown. FIG. 9 corresponds to a portion B surrounded by a broken line in FIG. In the present modification, the suppression unit 152 is an exposure scattering layer provided on the surface of the roll body 150. The suppressing unit 152 scatters the exposure 154 by the exposure scattering layer, thereby suppressing reflection of the exposure 154 on the surface of the support roll 130.

  The exposure scattering layer may be formed of, for example, a resin in which fine particles that scatter light are dispersed. The resin in which the fine particles and the like are dispersed may be formed with a uniform film thickness on the outer periphery of the roll main body 150, thereby preventing the base material 20 from being slipped during conveyance. Instead, the exposure scattering layer may be irregularities formed on the surface of the roll main body 150 by embossing or the like.

  7 to 9, the description has been given of the case where the suppression unit 152 is one of the exposure absorption layer, the exposure interference layer, and the exposure scattering layer. Instead, the suppression unit 152 includes an exposure absorption layer, an exposure interference layer, In addition, two or more of the exposure scattering layers may be laminated. For example, the suppressing unit 152 may be formed of an exposure absorption layer and an exposure interference layer or an exposure scattering layer provided on the exposure absorption layer.

  FIGS. 10A to 10C and FIGS. 11D to 11F show a method for manufacturing the optical film 10 in the present embodiment. The manufacturing method of the optical film in this embodiment can be implemented by the optical film manufacturing apparatus 100 shown in FIG.

  First, in FIG. 10A, the supply unit 108 continuously supplies the long TAC film base material 20. Here, a light absorption layer, an antireflection layer, or an antiglare layer may be provided in advance on one side or both sides of the substrate 20. Further, the substrate 20 may be a COP film instead of the TAC film.

  Next, in FIG.10 (b), the alignment layer coating part 112 apply | coats the coating liquid photoalignment resin 28 on one side, conveying the base material 20 to a longitudinal direction continuously. Further, the alignment layer drying unit 114 removes the solvent by drying the photo-alignment resin 28 while continuously transporting the substrate 20 in the longitudinal direction.

Next, in FIG. 10C, the alignment processing unit 116 applies a linearly polarized light parallel to the Y direction to a partial region of the photo-alignment resin 28 via the first exposure region 140 of the mask 138. First exposure is performed. The first exposure is performed, for example, by irradiating linearly polarized ultraviolet rays having a wavelength of 280 to 340 nm with an intensity of ²⁰ to 200 mW / cm ² . The exposed region in the photo-alignment resin 28 is cured by developing an alignment region 34 that is aligned in a direction parallel to the Y direction.

  In the first exposure, the alignment processing unit 116 irradiates a region of the film where the support roll 130 is in contact with the substrate 20 while continuously conveying the substrate 20 to the support roll 130 including the suppressing unit 152. To do. This prevents wrinkles and the like from occurring on the film being exposed. In addition, since the suppressing unit 152 suppresses the reflection of the exposure 154 on the surface of the support roll 130, the boundary of the alignment pattern is prevented from being blurred by the reflected light of the exposure 154.

  Next, in FIG. 11D, the alignment processing unit 116 applies an unexposed region of the photo-alignment resin 28 through the second exposure region 144 of the mask 138 by linearly polarized light parallel to the X direction. On the other hand, the second exposure is performed. In the linearly polarized light of the second exposure, ultraviolet rays having the same wavelength and the same intensity as those of the first exposure may be used. The exposed region of the photo-alignment resin 28 is cured by developing an alignment region 32 that is aligned in a direction parallel to the X direction.

  In the second exposure, the alignment processing unit 116 irradiates the region where the support roll 130 is in contact with the base material 20 while exposing the base material 20 to the support roll 130. This prevents wrinkles and the like from occurring on the film being exposed. Also in the second exposure, the suppression unit 152 of the support roll 130 prevents the alignment pattern from becoming unclear due to the reflected light of the exposure 154. Thus, according to the manufacturing method of the optical film of this embodiment, since the suppression part 152 prevents reflection of exposure in any of the two exposures, the boundary composed of the alignment region 32 and the alignment region 34 is clearly aligned. A patterned alignment layer 30 can be formed.

  Next, in FIG. 11E, the liquid crystal layer coating unit 120 applies an ultraviolet curable or thermosetting liquid crystal compound 38 to the alignment layer 30. Next, the liquid crystal layer drying unit 122 dries the liquid crystal compound 38 applied to the alignment layer 30. The liquid crystal compound 38 is aligned by forming an alignment pattern having a clear boundary corresponding to the alignment region 32 and the alignment region 34 of the alignment layer 30.

  Next, in the liquid crystal layer curing portion 124 of FIG. 11 (f), the liquid crystal compound 38 is cured by ultraviolet irradiation to form the liquid crystal layer 40 having the alignment regions 42 and 44. The ultraviolet rays applied to the liquid crystal compound 38 may be the same as or different from the wavelengths of the ultraviolet rays applied to the photo-alignment resin in FIGS. 10 (c) and 11 (d). Alternatively, the liquid crystal layer curing unit 124 may cure the liquid crystal compound 38 by heating.

  In this way, the optical film 10 having the liquid crystal layer 40 with a clear alignment pattern boundary is obtained by the manufacturing method shown in FIGS. 10 (a) to 11 (f). The obtained optical film 10 is wound around the winding unit 126. Thereafter, the long optical film 10 may be cut to an appropriate length for use in a display device or the like.

  12A and 12B show photographs in which the alignment pattern of the liquid crystal layer 40 of the optical film 10 is observed with crossed Nicols. FIG. 12A is a photograph obtained by observing the alignment pattern of the liquid crystal layer 40 of the optical film 10 manufactured using the support roll 130 not including the suppressing unit 152 with a crossed Nicol microscope. The observed alignment pattern has a substantially striped shape due to the first alignment region 300 and the second alignment region 310. However, minute irregularities are generated between the first alignment region 300 and the second alignment region 310, and the boundary is unclear.

  FIG. 12B is a photograph in which the alignment pattern of the liquid crystal layer 40 of the optical film 10 manufactured using the support roll 130 including the suppressing unit 152 is observed with crossed Nicols. There are no irregularities between the observed first alignment region 300 and the second alignment region 310, and the boundary is clear.

  FIG. 13 shows the configuration of the optical film 12 in the third modification of the present embodiment. The optical film 12 is the same as the optical film 10 shown in FIG. 1 except that the optical film 12 includes a light absorption layer 70 disposed closer to the base material 20 than the alignment layer 30.

  The light absorption layer 70 is a layer that absorbs light having a wavelength that cures the photo-alignment resin 28 forming the alignment layer 30, for example, ultraviolet rays. The light absorption layer 70 can be formed from a hard coat material, and is formed from, for example, a polymer mainly composed of a polyfunctional monomer containing a (meth) acryloyloxy group.

  Since the light absorption layer 70 absorbs the exposure 154 that has passed through the photo-alignment resin 28 and the exposure 154 that has been reflected by the support roll 130 during the exposure of the photo-alignment resin 28, the alignment pattern having a clear boundary on the upper surface thereof. The alignment layer 30 formed with can be formed. Moreover, since the light absorption layer 70 transmits visible light, the optical characteristics of the optical film 12 are not impaired. Thereby, the stereoscopic display device provided with the optical film 12 on the image output side can display a high-quality stereoscopic image with little crosstalk. Further, the light absorption layer 70 may be provided not on the surface of the base material 20 and the alignment layer 30 but on the surface opposite to the alignment layer 30 among both surfaces of the base material 20.

  FIG. 14 shows the configuration of the optical film 14 in the fourth modification of the present embodiment. The optical film 14 is the same as the optical film 12 shown in FIG. 13 except that the optical film 14 further includes an antireflection layer 80 disposed on the surface opposite to the side where the alignment layer 30 is provided on both surfaces of the substrate 20. It is. The antireflection layer 80 suppresses reflected light by optical interference. The antireflection layer 80 is formed of a resin having a low refractive index with respect to the base material 20 so as to have a thickness of ¼ with respect to a visible light wavelength (for example, 550 nm). As the resin having a low refractive index, for example, an ultraviolet curable resin in which silica particles having an average particle diameter of 0.5 to 200 nm, which has been reduced in refraction due to the hollow structure inside, is dispersed may be used.

  The anti-reflection layer 80 reflects not only visible light but also ultraviolet light that has passed through the photo-alignment resin 28 during exposure of the photo-alignment resin 28 and reflects and interferes with the interface between the base material 20 and the support roll. The exposure 154 reflected by the interface 130 is prevented from entering the photo-alignment resin 28. Thus, in this modification, the light absorption layer 70 and the antireflection layer 80 contribute to the sharpening of the alignment pattern of the alignment layer 30.

  The optical film 14 may include an antiglare layer instead of the antireflection layer 80. The antiglare layer is formed of a resin or the like in which fine particles that scatter light are dispersed, and light scatters the exposure 154 incident during the exposure. Thereby, since the anti-glare layer suppresses the reflected light from the support roll 130 of the exposure 154, the same effect as the anti-reflection layer 80 is achieved.

  The optical film 14 may further include another light absorption layer instead of the antireflection layer 80. Another light absorption layer may be the same as the light absorption layer 70 in the third modification.

  Tables 1 to 3 show Comparative Examples 1 to 8 and Examples 1 to 13 of this embodiment. The “film” column of the table shows the configuration of the film on which the alignment layer 30 is formed by applying the photo-alignment resin 28 in each comparative example and example. TAC corresponds to the TAC film used as the substrate 20, LR corresponds to the antireflection layer 80, AG corresponds to the antiglare layer, and HC corresponds to the light absorption layer 70 and the like. The photo-alignment resin 28 is applied to the (alignment layer) side of the film. For example, (alignment layer) / HC / TAC / AG of Comparative Example 5 is provided with an antiglare layer on one side of the TAC film and a light absorption layer on the surface opposite to the antiglare layer of the TAC film. It means that the photo-alignment resin 28 is applied on the absorption layer.

  Thereafter, the film was supported by the support roll 130, and the alignment layer 30 was formed by exposing the photo-alignment resin. Here, “Yes” in the “Exposure Absorption Layer” column of the table indicates that the support roll 130 includes the exposure absorption layer as the suppression unit 152, and “No” indicates that the support roll 130 does not include the suppression unit 152. Show. “Between support rolls” in the “Exposure position” column indicates that exposure was performed on an area stretched between two support rolls 130 of the film (exposure between rolls). It shows that the exposure was performed on the area of the film that was in contact with the support roll 130 (back roll exposure).

  Thereafter, the liquid crystal layer 40 was applied on the alignment layer 30, dried, and UV-cured to obtain optical films of comparative examples and examples. Subsequently, the optical films obtained in the respective comparative examples and examples were cut out to a predetermined size, and observed by overlapping the polarizing plate with the liquid crystal layer 40 placed on the upper surface. Each optical film was evaluated from the viewpoint of the sharpness of the boundary portion of the alignment pattern.

  In the table, “X” in the “Wrinkle generation” column indicates that the manufactured optical film was wrinkled, and “◯” indicates that no wrinkle was generated. X in the “sharpness of boundary portion” column indicates that unevenness exceeding 10 μm has occurred from the average line at the boundary of the alignment pattern of the liquid crystal layer 40, Δ indicates that 5-10 μm unevenness has occurred, Indicates that irregularities of 5 μm or less occurred. The smaller the unevenness, the larger the tolerance of alignment when the optical film is aligned and bonded to the image display unit 1300 of the LCD. For example, for an image display unit 1300 in which a black matrix having a width of 30 μm is formed between pixels, if the unevenness is 10 μm or less, a bonding position error of 10 μm or more can be allowed, and the unevenness is 5 μm or less. If there is, a bonding error of 20 μm or more can be allowed. In addition, when the optical film is bonded, the optical film expands and contracts due to the stress of bonding, but the effect of the expansion and contraction can be reduced as the unevenness is smaller. When the unevenness was 5 μm or less, the unevenness was hardly visible with a microscope.

  As shown in Table 1, in Comparative Examples 1 to 7 in which the photo-alignment resin 28 was exposed between the support rolls 130, wrinkles were generated in the manufactured optical film. Moreover, in the comparative example 8 which exposed the photo-alignment resin 28 on the support roll 130 which does not contain the suppression part 152, the boundary of the orientation pattern of the liquid crystal layer 40 of the manufactured optical film became unclear.

  FIG. 15 shows a photograph in which the boundary of the alignment pattern of the liquid crystal layer 40 of the optical film obtained in Comparative Example 8 is magnified 500 times with an optical microscope and observed with crossed Nicols. As shown in the figure, irregularities occur between the alignment patterns of the liquid crystal layer 40, and the boundary is unclear. The unevenness at the boundary of the alignment pattern exceeds 10 μm from the average line (thick line in the figure). The average line is, for example, a convex reference line provided in parallel with the alignment pattern boundary line from the most protruding convex portion of the unevenness, and a concave reference provided in parallel with the alignment pattern boundary line from the most depressed concave portion of the unevenness. It is an intermediate line with the line.

  In addition, when using an optical film for a three-dimensional display device, it is preferable that the unevenness from the average line is within 10 μm, and the boundary between the plurality of alignment regions is within 5 μm so that crosstalk can be sufficiently suppressed. More preferably.

  On the other hand, in Examples 1-13 which exposed the photo-alignment resin 28 on the support roll 130, wrinkles did not generate | occur | produce in the manufactured optical film. Further, Examples 1 to 6 in which one or more of the light absorption layer, the antireflection layer, and the antiglare layer are provided on the base material 20 and Examples 7 to 7 manufactured using the support roll 130 including the exposure absorption layer. In No. 13, the unevenness | corrugation exceeding 10 micrometers did not arise in the boundary of the orientation pattern of the liquid crystal layer 40 of the manufactured optical film.

  In particular, in the optical films of Examples 8 to 13 manufactured using the support roll 130 including one or more of the light absorption layer, the antireflection layer, and the antiglare layer on the base material 20 and further including the exposure absorption layer, The sharpness of the alignment pattern boundary of the liquid crystal layer 40 was very excellent, and no irregularities were observed at the boundary.

  FIG. 16 shows a photograph in which the boundary of the alignment pattern of the liquid crystal layer 40 of the optical film obtained in Example 10 was observed with crossed Nicols. As shown in the figure, there is almost no unevenness between the alignment patterns of the liquid crystal layer 40, and the boundary is very clear.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 Optical film, 12 Optical film, 14 Optical film, 20 Base material 28 Photo-alignment resin, 30 Alignment layer, 32 Alignment area | region, 34 Alignment area | region 38 Liquid crystal compound, 40 Liquid crystal layer, 42 Alignment area | region 44 Alignment area | region 50 Alignment direction , 60 orientation direction, 70 light absorption layer, 80 antireflection layer 100 optical film manufacturing apparatus, 108 supply unit, 112 orientation layer coating unit 114 orientation layer drying unit, 116 orientation processing unit, 120 liquid crystal layer coating unit 122 liquid crystal layer Drying unit, 124 Liquid crystal layer curing unit, 126 Winding unit 130 Support roll, 132 Transport roll, 134, 136 Exposure unit 138 Mask, 140 First exposure region, 142 Opening, 144 Second exposure region 146 Opening, 148 Arrow, 149 Arrow, 150 Roll body, 152 Suppressing portion 154 Exposure, 300 First alignment region, 310 Second alignment region 1000 stereoscopic display device, 1200 light source, 1300 image display unit 1500 light source side polarizing plate, 1600 image generation unit, 1620 right eye image generation region 1640 left eye image generation region 1700 emission side polarizing plate

Claims (20)

An optical film manufacturing apparatus for manufacturing an optical film having a plurality of orientation regions while continuously conveying a long film,
A support roll for supporting the film provided with the photo-alignment resin;
The photo-alignment resin is arranged opposite to the support roll, and the photo-alignment resin of the film is exposed to polarized light through a mask to cause the photo-alignment resin to exhibit the plurality of alignment regions having different molecular orientation directions. An exposure unit,
The said support roll is an optical film manufacturing apparatus which has the suppression part which suppresses reflection of the said exposure in the roll main body and the said roll main body.   The optical film manufacturing apparatus according to claim 1, wherein the polarized light is ultraviolet light.   The optical film manufacturing apparatus according to claim 1, wherein the suppression unit is an exposure absorption layer that absorbs the polarized light and suppresses reflection of the polarized light.   The optical film manufacturing apparatus according to claim 3, wherein the exposure absorption layer is a layer made of a black paint.   The optical film manufacturing apparatus according to claim 1, wherein the suppression unit is an exposure interference layer that interferes with the exposure and suppresses reflection of the exposure.   The optical film manufacturing apparatus according to claim 1, wherein the suppression unit is an exposure scattering layer that scatters the exposure and suppresses reflection of the exposure.   The optical film manufacturing apparatus according to any one of claims 1 to 6, wherein a reflectance of the support roll with respect to the exposure is 5% or less. An application step of applying a photo-alignment resin to a long film and drying;
While continuously transporting the film in the longitudinal direction, the photo-alignable resin is exposed to polarized light through a mask to cause the photo-alignable resin to exhibit a plurality of alignment regions having different molecular orientation directions. An exposure stage,
The exposure step is a step of exposing a region of the film that is in contact with a support roll,
The said support roll is provided with the control part which is provided in the roll main body and the surface of the said roll main body, and suppresses the reflection of the said exposure. The manufacturing method of an optical film.   The method for producing an optical film according to claim 8, wherein the polarized light is ultraviolet light.   The method for producing an optical film according to claim 8, wherein the suppression unit is an exposure absorption layer that absorbs the exposure and suppresses reflection of the exposure.   The method for producing an optical film according to claim 10, wherein the exposure absorption layer is a layer made of a black paint.   The method for producing an optical film according to claim 8, wherein the suppression unit is an exposure interference layer that interferes with the exposure and suppresses reflection of the exposure.   The method for producing an optical film according to claim 8, wherein the suppressing unit is an exposure scattering layer that scatters the exposure and suppresses reflection of the exposure.   The method for producing an optical film according to claim 8, wherein a reflectance of the support roll with respect to the exposure is 5% or less. The optical film manufactured by the manufacturing method as described in any one of Claim 8 to 14. An alignment layer formed of a photo-alignment resin and having a plurality of alignment regions having different alignment directions of molecules;
A transparent substrate that supports the alignment layer;
An optical film comprising: a light absorption layer that is disposed closer to the substrate than the previous alignment layer and absorbs light having a wavelength that cures the photoalignable resin. The optical film according to claim 16, further comprising: an antireflection layer that is disposed on a surface opposite to the side on which the alignment layer is provided on both surfaces of the base material and suppresses reflected light by light interference. The optical film according to claim 16, further comprising an antiglare layer that is disposed on a surface opposite to the side on which the alignment layer is provided on both surfaces of the base material and suppresses reflected light by light scattering. An optical film having a plurality of alignment regions having different alignment directions of molecules,
An optical film in which irregularities from an average line are within 10 μm at boundaries between the plurality of alignment regions.   The optical film according to claim 19, wherein unevenness from an average line is within 5 μm at a boundary between the plurality of alignment regions.