JP2015018009A - Optical film, image display device, molding die for optical film, method for manufacturing optical film, and method for manufacturing molding die for optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy of a retardation layer as compared to conventional technology in a configuration of a method for producing a retardation layer by curing a liquid crystal material while aligning the material by alignment regulation force of an aligned layer.SOLUTION: An optical film includes a substrate 2 made of a transparent film material, an aligned layer 3 having a line-shaped unevenness form formed on the substrate 2, and a retardation layer 4, which is formed from a liquid crystal material that is solidified while maintaining refractive index anisotropy by alignment regulation force of the aligned layer 3 and which gives a retardation to transmitted light. The aligned layer 3 is configured in such a way that an extending direction of the line-shaped unevenness form is varied along a width direction of the substrate 2; and the extending direction of the line-shaped unevenness form is set to compensate a change in a slow phase axis direction of the retardation layer 4 depending on the direction of an optical axis in a portion of the substrate 2.

Description

  The present invention relates to an optical film such as a pattern retardation film applied to three-dimensional image display by a passive method.

  In recent years, flat panel displays capable of three-dimensional display have been provided. Here, in order to perform three-dimensional display on a flat panel display, it is usually necessary to selectively provide a right-eye image and a left-eye image to the viewer's right eye and left eye in some manner. . As a method for selectively providing a right-eye image and a left-eye image, for example, a passive method is known. This passive three-dimensional display method will be described with reference to the drawings. FIG. 13 is a schematic diagram showing an example of a passive three-dimensional display using a liquid crystal display panel. In the example of FIG. 13, pixels that are continuous in the vertical direction of the liquid crystal display panel are sequentially and alternately assigned to a right-eye pixel that displays a right-eye image and a left-eye pixel that displays a left-eye image. And driving with the image data for the left eye, thereby displaying the image for the right eye and the image for the left eye simultaneously. As a result, the screen of the liquid crystal display panel is alternately switched into a region for displaying an image for the right eye and a region for displaying an image for the left eye, for example, by a band-shaped region in which the short side is vertical and the long side is horizontal. It is divided.

  Furthermore, in the passive method, a pattern retardation film is placed on the panel surface of the liquid crystal display panel, and light emitted from the linearly polarized light from the right-eye and left-eye pixels is converted into circularly polarized light with different rotation directions for the right-eye and left-eye. To do. Therefore, in the pattern retardation film, two types of band-like regions in which the slow axis direction (direction in which the refractive index is maximum) are orthogonal to each other are sequentially formed corresponding to the setting of the region in the liquid crystal display panel. Thus, in the passive method, glasses equipped with corresponding polarizing filters are worn, and a right-eye image and a left-eye image are selectively provided to the viewer's right eye and left eye, respectively. Here, as the slow axis direction of the adjacent band-like region, a combination of +45 degrees and −45 degrees, or 0 degrees and +90 degrees with respect to the horizontal direction is usually employed. In the example of FIG. 13, the long side direction of the screen is shown as the horizontal direction in accordance with the name in the normal image display device.

  This passive method can also be applied to a liquid crystal display device with a slow response speed, and can also display three-dimensionally with a simple configuration using a pattern retardation film and circularly polarized glasses.

  The pattern phase difference film according to this passive method requires a pattern-like phase difference layer that gives a phase difference to transmitted light corresponding to the allocation of pixels. With respect to this pattern retardation film, Patent Document 1 discloses a method for forming a retardation layer by forming a photo-alignment film with controlled alignment regulating force on a glass substrate and patterning the alignment of liquid crystals with this photo-alignment film. Is disclosed. For this alignment film, for example, a method has been proposed in which a fine line-shaped uneven shape formed on the surface of a molding die is molded into a molding resin layer made of an ultraviolet curable resin or the like ( Patent Document 2). Instead of this, a method has also been proposed in which a polyimide film on a base material is rubbed (Patent Document 3).

  By the way, in the retardation layer of this kind of optical film, it is required to provide the desired retardation with high accuracy to the transmitted light. For this purpose, the liquid crystal material constituting the retardation layer is accurately aligned in the desired direction. It is required to make it. However, according to various examination results, there are variations in the direction of the optical axis in the base material for producing the alignment film, and the slow axis direction of the retardation layer changes due to the influence of the variation in the optical axis. As a result, it was found that the accuracy of the retardation layer deteriorated.

JP 2005-49865 A JP 2010-152296 A Special table 2007-50613 gazette

  The present invention has been made in view of such a situation, and in a configuration in which a liquid crystal material is cured in a state of being aligned by the alignment regulating force of the alignment film to produce a retardation layer, the retardation is compared with the conventional one. The accuracy of the layer can be improved.

  The present inventor has intensively studied to solve the above-mentioned problems, and arrived at the idea of setting the extending direction of the line-shaped uneven shape so as to correct the influence due to the variation of the optical axis in the substrate, and completed the present invention. It came to do.

(1) a substrate made of a transparent film material;
An alignment film with a line-shaped uneven shape formed on the substrate;
Formed of a liquid crystal material solidified in a state in which the refractive index anisotropy is maintained by the alignment regulating force of the alignment film, and comprising a retardation layer that imparts a retardation to transmitted light,
The alignment film is
The extension direction of the line-shaped uneven shape is set so as to change in the width direction of the base material so as to correct the change in the slow axis direction in the retardation layer due to the direction of the optical axis in each part of the base material. In addition, the extending direction of the line-shaped uneven shape is set.

  According to (1), in the optical film including the base material, the alignment film, and the retardation layer, the change in the slow axis direction in the retardation layer due to the direction of the optical axis in each part of the base material can be reduced. The accuracy of the retardation layer can be improved as compared with the prior art.

  (2) An image display device in which the optical film according to (1) is disposed on the viewer side of the image display panel.

  According to (2), an image display device can be configured using an optical film including a highly accurate retardation layer.

(3) In a mold for forming by a roll plate that molds a line-shaped uneven shape formed on the peripheral side surface and uses it for preparation of an alignment film,
Produced by the alignment regulating force of the alignment film according to the direction of the optical axis in each part of the film material that is set so that the extending direction of the line-shaped uneven shape changes in the direction along the rotation axis. The phase difference layer is set so as to correct the change in the slow axis direction.

  According to (3), in the case of producing an alignment film by continuous shaping treatment of a long film material, and further producing a retardation layer, in the retardation layer depending on the direction of the optical axis in each part of the film material. The change in the slow axis direction can be corrected, thereby improving the accuracy of these retardation layers as compared with the conventional case.

(4) An alignment film creating step for producing an alignment film with a line-shaped uneven shape on a substrate made of a transparent film material;
A phase difference layer creating step of producing a phase difference layer that solidifies a liquid crystal material while maintaining refractive index anisotropy by the orientation regulating force of the alignment film and gives a phase difference to transmitted light;
The alignment film is
The extension direction of the line-shaped uneven shape is set so as to correct the change in the slow axis direction in the retardation layer depending on the direction of the optical axis in each part of the substrate.

  According to (4), when an optical film is prepared by sequentially preparing a base material, an alignment film, and a retardation layer, the change in the slow axis direction in the retardation layer due to the direction of the optical axis in each part of the base material is changed. The accuracy of the retardation layer can be improved as compared with the conventional case.

(5) In the manufacturing method of the mold for molding by the roll plate which molds the line-shaped uneven shape formed on the peripheral side surface and is used for the preparation of the alignment film,
A rubbing treatment step for producing the line-shaped uneven shape by pressing a rotating rubbing roll against the rotating base material and moving the rotating base material in a direction along the rotation axis of the base material,
The line-shaped uneven shape is produced so that the extending direction of the line-shaped uneven shape changes in the direction along the rotation axis.

  According to (5), when producing a retardation layer by producing an alignment film on a substrate made of a long film material, a change in the slow axis direction in the retardation layer depending on the direction of the optical axis in each part of the substrate. Therefore, the accuracy of these retardation layers can be improved as compared with the conventional case.

  (6) In (5), by changing the inclination of the rubbing roll, the line-shaped uneven shape is prepared so that the extending direction of the line-shaped uneven shape is changed in the direction along the rotation axis. .

  (7) In (5) or (6), the extending direction of the line-shaped uneven shape is changed in the direction along the rotation axis due to the change in the rotation speed of the rubbing roll with respect to the rotation speed of the base material. In addition, the line-shaped uneven shape is produced.

  According to (6) or (7), the extending direction of the line-shaped uneven shape can be changed in the direction along the rotation axis with a more specific configuration.

  The present invention can improve the accuracy of the retardation layer as compared with the conventional one in a configuration in which the retardation layer is prepared by curing in a state where the liquid crystal material is aligned by the alignment regulating force of the alignment film.

It is a figure which shows the pattern phase difference film which concerns on 1st Embodiment of this invention. It is a figure which shows the manufacturing process of the pattern phase difference film of FIG. It is a figure which shows the manufacturing process of a roll plate. It is a figure which shows the continuation of FIG. It is a figure where it uses for description of a rubbing process. It is a figure with which it uses for variable description of the extension direction about a line-shaped uneven | corrugated shape. It is a figure which shows a specific variable structure. It is a figure where it uses for description of the variable of the extension direction which concerns on 2nd Embodiment. It is sectional drawing which shows the image display apparatus which concerns on 3rd Embodiment of this invention. It is a figure where it uses for description of the optical film applied to the image display apparatus of FIG. It is sectional drawing which shows the transfer film which concerns on the optical film of FIG. It is a figure where it uses for description of the preparation method of the alignment film which concerns on 3rd Embodiment. It is a figure where it uses for description of a pattern phase difference film.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Overall Configuration of First Embodiment]
FIG. 1 is a diagram showing a pattern retardation film applied to the image display device according to the first embodiment of the present invention. In the image display device according to the first embodiment, the pixels of the liquid crystal display panel that are continuous in the vertical direction (the left-right direction is the corresponding direction in FIG. 1) sequentially and alternately display the right-eye image. The pixels are assigned to the left-eye pixels for displaying the left-eye image and the left-eye image, and are driven by the right-eye and left-eye image data, respectively. As a result, the image display device alternately divides the display screen into a band-like region for displaying an image for the right eye and a band-like region for displaying an image for the left eye, so that the image for the right eye and the image for the left eye are divided. Display at the same time. In this image display device, the pattern phase difference film 1 shown in FIG. 1 is disposed on the panel surface of the liquid crystal display panel, and the pattern phase difference film 1 corresponds to light emitted from pixels for the right eye and the left eye, respectively. To give the phase difference. Thereby, this image display apparatus displays a desired three-dimensional image by a passive method.

  Here, in the pattern retardation film 1, an alignment film 3 and a retardation layer 4 are sequentially formed on one surface of a substrate 2 made of a transparent film such as TAC (triacetyl cellulose). The pattern retardation film 1 is formed of a liquid crystal material that is solidified (cured) in a state where the retardation layer 4 retains refractive index anisotropy, and the alignment of the liquid crystal material is patterned by the alignment regulating force of the alignment film 3. To do. In FIG. 1, the orientation of the liquid crystal molecules is exaggerated by an elongated ellipse. By this patterning, the pattern phase difference film 1 has a certain width corresponding to the pixel assignment in the liquid crystal display panel, and the right eye region (first region) A and the left eye region (second region). ) B and B are sequentially formed in a band shape, and give phase differences corresponding to light emitted from the right-eye and left-eye pixels, respectively.

  The alignment film 3 is coated on the surface of the base material 2 with a molding resin, which is a resin used for molding a fine line-shaped uneven shape. A shape is created. In this embodiment, an ultraviolet curable resin is applied to the shaping resin. As the ultraviolet curable resin, it is possible to apply an acrylate-based, methacrylate-based, epoxy-based monomer, a prepolymer, or a mixture thereof with a photopolymerization initiator such as benzophenone or aromatic iodonium added. it can.

  As a result, after the ultraviolet curable resin 5 is applied to the surface of the substrate 2, the pattern retardation film 1 is formed with minute line-shaped irregularities on the surface of the ultraviolet curable resin 5. The alignment film 3 is formed by the uneven shape. The pattern phase difference film 1 transfers a fine line-shaped uneven shape produced on the surface of a mold for molding to be described later to produce a fine line-shaped uneven shape related to the alignment film 3. The retardation layer 4 is patterned by the orientation regulating force. For this reason, in the alignment film 3, strip-shaped regions respectively corresponding to the strip-shaped regions A and B for the right eye and the left eye are alternately formed, and minute line-shaped uneven shapes are respectively produced. Here, the minute line-shaped uneven shape is formed by a line (line) uneven shape extending in one direction, and the direction extending in this one direction differs 90 degrees between the right-eye region A and the left-eye region B. And is inclined at 45 degrees with respect to the extending direction of each region (the horizontal direction, the direction connecting the upper right and the lower left in FIG. 1). In addition to the basic structure shown in FIG. 1, the pattern retardation film 1 is provided with an adhesive layer, a separator film, an antireflection film, and the like as necessary.

  In addition, this fine line-shaped uneven shape has a 10-point average roughness (Rz) of 10 nm or more and 45 nm or less, and an average surface roughness (Ra) of 1 nm or more and 4 nm or less. Thereby, the alignment film 3 can secure sufficient adhesion strength between the alignment layer 4 and sufficiently reduce the variation of the retardation layer 4 related to so-called black luminance.

  FIG. 2 is a schematic diagram showing a manufacturing process of the pattern retardation film 1. In the manufacturing process 10, the base material 2 is provided by a roll, and the base material 2 is supplied from a supply reel 11. In the manufacturing process 10, a coating solution of an ultraviolet curable resin is applied to the substrate 2 by the die 12. In this manufacturing process 10, the roll plate 20 is a cylindrical mold for molding in which the line-shaped uneven shape related to the alignment film 3 of the pattern retardation film 1 is formed on the peripheral side surface. In the manufacturing process 10, the substrate 2 coated with the ultraviolet curable resin is pressed against the peripheral side surface of the roll plate 20 by the pressure roller 14, and the ultraviolet curable resin is applied by irradiating the ultraviolet rays with the ultraviolet irradiation device 15 made of a high-pressure mercury lamp. Harden. Thereby, the manufacturing process 10 transfers the line-shaped uneven | corrugated shape formed in the surrounding side surface of the roll plate 20 to the base material 2. FIG. Thereafter, the substrate 2 is peeled off integrally with the ultraviolet curable resin cured from the roll plate 20 by the peeling roller 16, and a liquid crystal material is applied by the die 19. Thereafter, the liquid crystal material is cured by irradiation with ultraviolet rays from the ultraviolet irradiation device 17, thereby solidifying the liquid crystal material while maintaining the refractive index anisotropy by the alignment regulating force of the alignment film 3, thereby producing the retardation layer 4. Then, it is wound up on the take-up reel 18. The pattern retardation film 1 is produced by forming an adhesive layer, an antireflection layer, and the like on the sheet material wound on the take-up reel 18 as necessary, and then cutting it to a desired size. Thereby, the pattern phase difference film 1 is efficiently mass-produced by continuously processing the substrate 2 provided by the roll.

  3 and 4 are diagrams showing a manufacturing process of the roll plate 20 which is a mold for manufacturing the pattern retardation film. 3 and 4, regions corresponding to the regions A and B of the pattern retardation film 1 are indicated by symbols ARA and ARB, respectively. In this manufacturing process, the peripheral side surface of the base material 40 is smoothed by cutting in the chamfering process. Subsequently, in this manufacturing process, the underlayer 41 is produced (FIG. 3A). Here, the base material 40 is a cylindrical metal material corresponding to the outer shape of the roll plate 20. The base material 40 is preferably a metal material from the viewpoint of ease of processing and dimensional stability, and more preferably nickel, chromium, stainless steel, copper, or the like. In this embodiment, the base material 40 is made of copper.

  The underlayer 41 is provided to reinforce the adhesion to the base material 40 with respect to the material layer provided on the upper layer. In this embodiment, the foundation layer 41 is formed with a thickness of 500 nm from a nickel layer doped with phosphorus by electroless plating.

Subsequently, in this step, the first inorganic material layer 42 is formed on the base layer 41. In this embodiment, a nickel layer is applied to the first inorganic material layer 42, and a nickel layer having a thickness of 100 nm is formed by sputtering. In addition, although various inorganic materials, such as a metal material, an inorganic oxide, an inorganic nitride, an inorganic carbide, can be widely applied to this 1st inorganic material layer 42, it is chromium, titanium from the ease of processing etc. , nickel, tungsten, stainless steel-based metallic material, _{aluminum, SiO 2, SiOx, Al 2} O 3, Cr 2 O 3, TiO 2, Si 3 N 4, AlN, TiN, SiO x N y, SiC, WC, DLC , etc. Can be applied.

  Subsequently, in this step, as shown in FIG. 3B, a fine line-shaped uneven shape is formed on the entire surface of the first inorganic material layer 42 in the first uneven shape forming step. Here, this line-shaped uneven shape is a minute line-shaped uneven shape corresponding to the uneven shape of the right-eye region or the left-eye region of the alignment film 3. In this embodiment, the concavo-convex shape is produced by a rubbing process using a rubbing cloth. In this embodiment, the rubbing process is shown by the rubbing roll R.

  Subsequently, in this step, a mask 43 in which a region ARA corresponding to the right eye region A is covered with a resist material and a region ARB corresponding to the left eye region B is exposed with a resist material in the mask manufacturing step is manufactured (FIG. 3 (c)). That is, in this step, a positive resist agent is applied to the entire surface, and then exposed and developed to produce a mask that exposes the region ARB corresponding to the left-eye region B. The resist material is not particularly limited, and a negative resist material may be applied. In addition, various methods can be widely applied even in the coating method and the exposure method.

Subsequently, as shown in FIG. 4D, in the thin film manufacturing process, the second inorganic material layer 44 is formed on the entire surface. In this embodiment, a nickel layer having a thickness of 100 nm is formed by sputtering, and thereby the nickel layer is applied to the second inorganic material layer 44. The second inorganic material layer 44 can be widely applied to various inorganic materials such as a metal material, an inorganic oxide, an inorganic nitride, and an inorganic carbide. However, in terms of ease of processing, chromium, titanium, nickel, tungsten, stainless steel-based metallic material, _{aluminum, SiO 2, SiO x, Al} 2 O3, Cr 2 O 3, TiO 2, Si 3 N 4, AlN, TiN, SiO x N y, SiC, WC, and the like DLC Selected.

  Subsequently, as shown in FIG. 4E, in the second concavo-convex shape manufacturing step, a direction different from the extending direction of the line-shaped concavo-convex shape in the first inorganic material layer 43 (in this embodiment, the first inorganic material The entire surface is rubbed in a direction that forms an angle of 90 degrees with the rubbing direction in the layer 43, and an uneven shape is formed on the surface of the second inorganic material layer (nickel layer) 44. Thereafter, as shown in FIG. 4F, in the manufacturing process, the mask 43 is removed together with the second inorganic material layer 44 as an upper layer in the subsequent resist removing process. Thus, in this manufacturing process, the concavo-convex shape corresponding to the regions A and B of the alignment film 3 is prepared by two concavo-convex shape manufacturing processes, and the roll plate 20 is manufactured.

  For the rubbing process of the areas ARA and ARB related to the roll plate 20, various methods can be widely applied, for example, when the areas ARA and ARB are alternately masked and selectively rubbed.

[Rubbing treatment]
FIG. 5 is a diagram for explaining the rubbing process. The roll plate 20 has a fine line-shaped uneven shape to be subjected to a shaping process by a rubbing process using a rubbing roll R. The base material 40 according to the description of FIG. 9 is provided with the base layer 41 and the like on the peripheral side surface as described above with reference to FIGS.

  Here, the rubbing roll R is a cylindrical member around which a rubbing cloth to be subjected to a rubbing process is wound. In the rubbing process, as shown by arrow A, the base material 40 is rotated at a constant rotational speed, and the rubbing roll R rotating at a constant rotational speed as shown by arrow B is tilted by a predetermined angle. The rubbing roll R is pressed against the peripheral side surface of the material 40 and moved in the direction along the rotation axis of the base material 40 as indicated by an arrow C, and thereby the periphery of the base material 40 is rubbed by the rubbing cloth provided on the rubbing roll R. Rub the sides to rub the entire surface.

  The rubbing cloth can be widely applied, for example, various kinds of cloth materials that can be used for rubbing treatment, natural leather, artificial leather, etc. In this embodiment, the rubbing cloth is a cloth material in which a large number of fibers are planted. Rubbing with a blanket. The material for the rubbing cloth is appropriately selected from cellulose, rayon, polyamide (nylon: registered trademark), polyolefins such as polyethylene, acrylic resin, polyester resin, urethane resin and the like. A general pile having a pile length of 1 to several mm, a density of 20 to 40,000 filaments / cm2, a pile diameter of several tens to 300 dinars, and a pile number of about 250 to 1500 / cm2 is used. The preferred material is a flocked cloth using chemical fibers such as rayon and nylon with less rubbing residue. In this case, the pile length is 1-2 mm, the density is 2.5-35,000 filaments / cm2, and the pile diameter is 50 to 150 dinar, pile number 600 to 1000 / cm 2, and the spreading angle of the filament is 5 to 20 °.

  Here, when the base material 40 is rotated at a constant rotational speed in this way, the rotating rubbing roll R is tilted by a predetermined angle and pressed against the peripheral side surface of the base material 40 to perform the rubbing process. The extending direction z of the line-shaped unevenness formed on the side surface is determined by the peripheral speed y of the base material 40, the inclination θ of the rubbing roll R with respect to the base material 40, and the peripheral speed x of the rubbing roll R. As a result, in the roll plate 20, the rotation direction of the base material 40 and the base material 40 are set such that the extending direction z is an angle of +45 degrees and −45 degrees, respectively, with respect to the circumferential tangential direction of the roll plate 20. If the rubbing roll R is moved in the direction along the axis of rotation of the base material 40 as indicated by an arrow C with the inclination θ of the rubbing roll R and the rotational speed of the rubbing roll R set, a roll plate A line-shaped uneven shape can be formed uniformly on the entire surface of the 20 peripheral side surfaces.

  However, when the patterned retardation film 1 was produced using the roll plate 20 thus produced and the slow axis direction of the retardation layer 4 was measured, variation was detected in the width direction of the substrate 2. When the cause is variously examined, the direction of the optical axis changes in the width direction in the base material 2, and the phase difference changes in the width direction of the base material 2 in the retardation layer 4 due to the change in the direction of the optical axis. I found out. More specifically, when a roll plate is produced and molded so that the line-shaped uneven shape extends in a direction of 45 degrees obliquely with respect to the extending direction of the base material 2, the base material 2 corresponds to the extending direction. In the regions where the inclination of the optical axis is 0 degree and 5 degrees respectively, the slow axis direction in the retardation layer is 45 degrees and 50 degrees, respectively. As a result, it was found that a retardation layer could not be produced with high accuracy.

  In this case, in order to correct the slow axis direction in the retardation layer that changes depending on the direction of the optical axis of the base material in this way, if the extension direction of the line-shaped portion fine irregularities formed by rubbing is set, The influence of the orientation of the optical axis of the substrate can be effectively avoided, and the accuracy of the retardation layer can be improved. That is, when a roll plate is produced so that the line-shaped uneven shape is extended and is subjected to a shaping process, the line of the optical axis in the substrate 2 is inclined at 0 degree and 5 degrees with respect to the extending direction. If the extending direction of the concavo-convex shape is set to 45 degrees and 40 degrees, both the slow axis directions of the retardation layer at the 0 degree and 5 degree parts can be set to 45 degrees.

  Therefore, in this embodiment, as shown in FIG. 6 in comparison with FIG. 5, the inclination θ of the rubbing roll R is made different in the axial direction of the roll plate 20 so as to correct the direction of the optical axis in the substrate 2. Thus, the extending direction of the line-shaped unevenness formed by the shaping process is changed in the width direction of the substrate 2. The direction of the optical axis in the substrate 2 can be obtained by measurement of the substrate 2.

  More specifically, as shown in FIG. 7, in this embodiment, the rotation speed of the base material 40 and the rotation speed of the rubbing roll R are maintained at a constant speed, and further, as indicated by an arrow C, the base material. The rubbing roll R is moved in the direction along the rotation axis 40, and the inclination of the rubbing roll R is gradually changed as indicated by the symbols RA to RE, thereby changing the extending direction of the line-shaped unevenness. Thus, the production accuracy of the retardation layer is improved.

  That is, as indicated by the symbol RA, the rubbing process is performed at the start end side of the rubbing process by setting the inclination θ to 49 degrees, for example, and the rubbing roll R is moved to approximately 55.8 degrees at the position indicated by the reference numeral RB. Set and rub. Further, at the center (RC), the rubbing process is performed by setting the inclination θ to 56.5 degrees, and the rubbing process is performed at the sign RD by setting the inclination θ to 56.0 degrees. The inclination θ is restored.

  In this embodiment, the alignment regulating force of the alignment film 2 is set by applying the extension direction of the line-shaped uneven shape so as to be applied to the optical film by the pattern retardation film and correcting the variation of the optical axis in the substrate 2. In the configuration in which the retardation layer 4 is produced by curing in a state where the liquid crystal material is aligned, the accuracy of the retardation layer can be improved as compared with the conventional case.

[Second Embodiment]
FIG. 7 is a diagram for explaining the manufacturing process of the pattern retardation film according to the second embodiment of the present invention in comparison with FIG. This embodiment is configured in the same way as the first embodiment except that the rubbing process according to FIG. 7 is different.

  Here, in this embodiment, instead of changing the inclination θ of the rubbing roll R according to the position of the base material 40 in the rotation axis direction, the relative rotational speed of the rubbing roll R with respect to the base material 40 is varied. Specifically, the inclination θ is held at a constant value of 45 degrees. In this state, the base material 40 is rotated at a rotational speed of 10 rpm and the rubbing roll R is rotated at a rotational speed of 100 rpm at a location indicated by the symbol RA. Moreover, in the location shown with the code | symbol RB, the base material 40 is rotated with the rotational speed of 15 rpm, and the rubbing roll R is rotated with the rotational speed of 100 rpm. Moreover, in the location shown with the code | symbol RC, the base material 40 is rotated with the rotational speed of 20 rpm, and the rubbing roll R is rotated with the rotational speed of 180 rpm. Moreover, in the location shown with the code | symbol RD, the base material 40 is rotated with the rotational speed of 13 rpm, and the rubbing roll R is rotated with the rotational speed of 110 rpm. Moreover, in the location shown with the code | symbol RE, the base material 40 is rotated with the rotational speed of 10 rpm, and the rubbing roll R is rotated with the rotational speed of 104 rpm.

  As in this embodiment, even if the extending direction of the line-shaped uneven shape is changed by changing the relative rotational speed of the rubbing roll R with respect to the base material 40, the same effect as in the first embodiment is obtained. be able to. Further, in this case, the configuration relating to the change in the extending direction of the line-shaped uneven shape can be simplified as compared with the configuration according to the first embodiment.

  In addition, by changing the inclination θ of the rubbing roll R according to the position of the base material 40 in the rotation axis direction, and changing the relative rotational speed of the rubbing roll R with respect to the base material 40, the extending direction of the line-shaped uneven shape May be variable.

[Third Embodiment]
FIG. 9 is a diagram showing an image display apparatus according to the third embodiment of the present invention. In the image display device 51, an optical film 53 is disposed on the panel surface (viewer side surface) of the image display panel 52. Here, the image display panel 52 is an organic EL panel, for example, and displays a desired color image. The image display panel 52 is not limited to the organic EL panel, and various image display panels such as a liquid crystal display panel can be widely applied.

  The optical film 53 is an optical film that suppresses reflection of extraneous light arriving at the image display panel 52 by the function of a circularly polarizing plate. Therefore, the optical film 53 is configured by laminating a linear polarizing plate 55 and a quarter wavelength plate 56. The optical film 53 is peeled off a separator film (not shown) to expose the pressure-sensitive adhesive layer 54, and is then adhered and held on the panel surface of the image display panel 52 by the pressure-sensitive adhesive layer 54. Instead of the pressure sensitive adhesive, the optical film 53 may be arranged by various adhesives such as an ultraviolet curable resin, and an adhesive. The linearly polarizing plate 55 and the quarter wavelength plate 56 are integrated with each other through the adhesive layer 57. Here, although various adhesives such as an ultraviolet curable resin, a thermosetting resin, and a pressure sensitive adhesive can be widely applied, the adhesive layer 57 is made of an ultraviolet curable resin from the viewpoint of reducing the overall thickness. In this case, it can be formed with a thickness of about 1 μm.

  The quarter wavelength plate 56 includes a quarter wavelength retardation layer 58 that imparts a phase difference of ¼ wavelength to the transmitted light, and a ½ wavelength that imparts a phase difference of ½ wavelength to the transmitted light. It is comprised by the laminated body which bonded the phase difference layer 59 with the contact bonding layer 60. FIG. Thereby, the optical film 53 sufficiently suppresses reflection of extraneous light in a wide wavelength band used for displaying a color image.

  The quarter-wave plate 56 is used for the production of the quarter-wave retardation layer 58 and the half-wave retardation layer 59, and is used for the quarter-wave retardation layer 62 and the half-wave retardation layer. An alignment film 63 is provided on each of the image display panel 52 side and the linear polarizing plate 55 side, whereby an optical film 53 is produced by applying a transfer method to reduce the overall thickness and a quarter wavelength phase difference. The layer alignment film 62 and the ½ wavelength retardation layer alignment film 63 function as a protective layer to reduce damage to the ¼ wavelength retardation layer 58 and the ½ wavelength retardation layer 59.

  As a result, in the image display device 51, the ¼ wavelength phase difference layer 58, the ½ wavelength phase difference layer 59, and the linear polarizing plate 55 are sequentially arranged from the display screen side of the image display panel 52. Further, as shown in FIG. 10, the slow axes (indicated by arrows respectively) of the ½ wavelength phase difference layer 59 and the ¼ wavelength phase difference layer 58 with respect to the transmission axis of the linearly polarizing plate 55 indicated by arrows. These are arranged to form angles of 55 degrees and 73 degrees counterclockwise, respectively.

  The quarter-wave retardation layer alignment film 62 and the half-wave retardation layer alignment film 63 are formed by forming fine line-shaped uneven shapes on the surface, and the alignment regulation by the fine line-shaped uneven shapes. The liquid crystal material according to the quarter wavelength retardation layer 58 and the half wavelength retardation layer 59 is aligned by force. The quarter-wave retardation layer alignment film 22 and the half-wave retardation layer alignment film 23 have a 10-point average roughness (Rz) of 10 nm to 45 nm, and an average surface roughness. (Ra) is 1 nm or more and 4 nm or less. As a result, the quarter-wave retardation layer alignment film 22 and the half-wave retardation layer alignment film 23 are disposed between the corresponding quarter-wave retardation layer 58 and the half-wave retardation layer 59. Sufficient adhesion strength can be secured, and variations in the quarter-wave retardation layer 58 and the half-wave retardation layer 59 related to so-called black luminance can be sufficiently reduced.

  In this embodiment, the quarter-wave retardation layer alignment film 62 and the half-wave retardation layer alignment film 63 are formed by a molding process after a molding resin layer for molding is formed. A fine line-shaped uneven shape is created on the surface of the shaping resin layer. In this embodiment, an ultraviolet curable resin is applied to the shaping resin, and an acrylic ultraviolet curable resin is used. However, the present invention is not limited to this, and various resins used for the shaping process can be widely applied. it can.

  In addition, the fine line-shaped uneven shape related to the alignment film 63 for 1/2 wavelength phase difference layer and the alignment film 62 for 1/4 wavelength phase difference layer is formed by a line-shaped uneven shape extending in one direction. It is formed so that the direction extending in one direction is approximately 55 degrees and 73 degrees counterclockwise with respect to the transmission axis of the linearly polarizing plate 55, respectively.

  The quarter-wave retardation layer 58 and the half-wave retardation layer 59 are made of a liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy by the orientation regulating force of the corresponding orientation films 62 and 63. It is formed. More specifically, the quarter-wave retardation layer 58 and the half-wave retardation layer 59 are formed by laminating a polymerizable liquid crystal monomer on the alignment films 62 and 63, and then raising the temperature to the phase transition point. It is produced by polymerizing a polymerizable liquid crystal monomer by irradiation to fix the alignment state of the liquid crystal. Although the ¼ wavelength retardation layer 58 and the ½ wavelength retardation layer 59 can widely apply various liquid crystal materials applicable to this type of optical film, in this embodiment, the same material is used. Applied.

  Although various adhesives such as an ultraviolet curable resin, a thermosetting resin, and a pressure sensitive adhesive can be widely applied to the adhesive layer 60, an ultraviolet curable resin is applied from the viewpoint of reducing the overall thickness. In this case, it can be formed with a thickness of about 1 μm. In this embodiment, an ultraviolet curable resin applied to the preparation of the alignment film is applied. In the present invention, the adhesive layer 60 may be an adhesive layer.

  In the linear polarizing plate 55, the lower surface side of the base material 55A made of a transparent film such as TAC (triacetyl cellulose) is saponified, and then the optical functional layer 55B is disposed. In addition, 55 A of base materials replaced with this, poly (meth) acrylate methyl, poly (meth) acrylate butyl, (meth) acrylate methyl- (meth) acrylate butyl copolymer, (meth) acrylate methyl- A resin such as an acrylic resin such as a styrene copolymer, a glass such as soda glass, potash glass, lead glass, or quartz glass can be used.

  The optical functional layer 55B is a part that bears an optical function as a linearly polarizing plate, and is produced, for example, by adsorbing and orienting iodine compound molecules on a film material of polyvinyl alcohol (PVA).

  Thus, in the optical film 53, each of the quarter-wave plates 56 is configured by a laminate in which the quarter-wave retardation layer 58 and the half-wave retardation layer 59 are bonded by the adhesive layer 60, respectively. The ¼ wavelength phase difference layer 58 and the ½ wavelength phase difference layer 59 created by separate processes can be used, and thereby an alignment film and a phase difference layer are sequentially laminated. In this case, it can be created by effectively avoiding shortage of adhesion and insufficient adhesion, and as a result, it can be created with high stability and reliability.

  Further, the quarter-wave retardation layer alignment film 62 and the half-wave retardation layer alignment film 63 used for the production of the quarter-wave retardation layer 58 and the half-wave retardation layer 59 are respectively images. This is provided on the display panel 52 side and the linearly polarizing plate 55 side, whereby the transfer method is applied to produce the optical film 53 to reduce the overall thickness, and the 1/4 wavelength retardation layer alignment film 62, 1 / The alignment film 63 for the two-wavelength retardation layer can function as a protective layer, and damage to the quarter-wave retardation layer 58 and the half-wave retardation layer 59 can be reduced. The transfer method refers to, for example, when a desired layer is formed on a base material, the layer is not directly formed on the base material, but can be peeled once on a releasable support. After forming the transfer body by laminating the layers, the layer formed on the support is finally placed on the substrate (transfer base material) on which the layer is to be laminated according to the process, demand, etc. In this method, a desired layer is formed on the substrate by bonding and laminating, and then peeling and removing the support.

  In the optical film 53, the quarter wavelength plate 56 and the linear polarizing plate 55 are integrated by the adhesive layer 57, and the transfer method is applied to a series of processes related to this integration. Thus, in this embodiment, the substrate to be transferred is the linear polarizing plate 55, and the layers (transfer layers) used for transfer are the quarter-wave retardation layer alignment film 62 and the quarter-wave retardation layer 58. , An adhesive layer 60, a ½ wavelength retardation layer 59, and a ½ wavelength retardation layer alignment film 63.

  FIG. 11 is a diagram showing a configuration of a transfer film 61 that is a transfer body. The transfer film 61 is formed on a support substrate 65, a quarter-wave retardation layer alignment film 62, a quarter-wave retardation layer 58, an adhesive layer 60, a half-wave retardation layer 59, and a half. A wavelength retardation layer alignment film 63 and a substrate 64 are provided.

  Here, the support base material 65 is a base material that is detachably supported after the transfer layer is detachably supported and the transfer layer is bonded and laminated on the transfer target substrate. In this embodiment, a PET (Polyethylene terephthalate) film, which is a transparent film material, is applied, whereby the transfer film 61 is configured to be able to inspect optical characteristics. The PET film is subjected to corona treatment as necessary, whereby the adhesion force is appropriately set. The support substrate 65 may have a sheet shape as a whole. The support substrate 65 may be a resinous film material made of a resin such as a polyester resin such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene aphthalate, or a polyolefin resin such as polypropylene or polymethylpentene.

  When the peelability from the transfer layer is insufficient, a release layer that promotes peeling is provided on the support base material 65 on the transfer layer side. Here, the release layer can be applied with a material having relatively high adhesion to the support substrate 65 (low peelability) and low adhesion to the transfer layer (high peelability). . In this embodiment, the lowermost layer of the transfer layer is an alignment film 62 for a quarter wavelength retardation layer made of an ultraviolet curable resin. Polymer compound), fluorine-based resin, melamine resin, epoxy resin, or a mixture of these resins and other resins (acrylic resin, cellulose-based resin, polyester resin, etc.) as appropriate.

  Incidentally, when the peelability by the release layer is insufficient, a release layer may be provided between the support substrate 65 and the release layer, and the release layer may supplement the peelability by the release layer. . For the release layer, a material having relatively low adhesion to the support film (high peelability) and high adhesion to the release layer (low peelability) can be applied. More specifically, in this embodiment, the release layer includes an acrylic resin, a cellulose resin, a polyester resin, a urethane resin, a vinyl chloride-vinyl acetate copolymer, or a mixture of two or more selected from the above. Alternatively, a mixture of one or more selected from the above and other resins can be applied.

  The base material 64 is a base material that carries the transfer layer in a peelable manner and is subjected to peeling and removal as appropriate at the time of transfer or the like. In this embodiment, it is comprised similarly to the support body base material 65. FIG. In addition, also in the base material 64, in order to appropriately set the adhesion between the lower-layer alignment layer 63 for the half-wave retardation layer, corona treatment is performed as necessary, and a release layer and a release layer are provided. Can be formed.

  In the manufacturing process of the transfer film 61, the alignment film 63 for the ½ wavelength phase difference layer and the ½ wavelength phase difference layer 59 are formed on the base material 64. The alignment layer 62 for the retardation layer and the quarter wavelength retardation layer 58 are formed. In the manufacturing process, the ½ wavelength retardation layer 59 and the ¼ wavelength retardation layer 58 are bonded together by the adhesive layer 60, thereby creating the transfer film 61.

  In the manufacturing process of the optical film 53, only the base material 64 is peeled from the transfer film 61, and then attached to the linearly polarizing plate 55 through the adhesive layer 57 to produce the optical film 53.

  In this embodiment, the half-wave retardation layer alignment film 63 and the quarter-wave retardation layer alignment film 62 are formed into line-shaped irregularities by rubbing treatment similar to that described above for the first or second embodiment. This is executed by a forming process using a roll plate having a shape, which effectively avoids deterioration of the characteristics of the retardation layers 58 and 59 due to changes in the optical axis of the support base material 65 and the base material 64.

  In this embodiment, when producing a half-wave retardation layer and a quarter-wave retardation layer, further laminating these retardation layers to produce an optical film as a transfer body, Even when an optical film integrated with a linear polarizing plate is produced by a transfer body, the same effects as those of the first or first embodiment can be obtained.

[Fourth Embodiment]
FIG. 12 is a diagram for explaining an alignment film forming step according to the fourth embodiment of the present invention. In this embodiment, it is a figure where it uses for description of the manufacturing process of the pattern phase difference film regarding this alignment film. This embodiment has the same configuration as that of the third embodiment except that the configuration relating to the alignment film forming step is different.

  Here, in this alignment film forming step, a material film for forming an alignment film such as a polyimide film is formed on the surface of the base material 64, 65 in the process of transporting the base material 64, 65 drawn from the reel, and this alignment film preparation is performed. An alignment film is prepared by rubbing the material film surface for use. Various configurations can be applied to this material film. If practically sufficient, an alignment film may be produced by directly rubbing the surfaces of the base materials 64 and 65 without providing a material film.

  In the alignment film creating step, a plurality of rubbing rolls RA to RE are arranged in the width direction of the base materials 64 and 65 so as to cross the base materials 64 and 65. Each of the rubbing rolls RA to RE is configured such that the inclination and / or the rotation speed can be varied, and as described above for the rubbing process of the roll plate in the first embodiment and / or the rubbing process of the roll plate in the second embodiment. As described above, the inclination and / or the rotational speed are set so as to correct the change in the direction of the optical axis in each part of the bases 64 and 65, and thereby the direction of the optical axis in each part of the bases 64 and 65 depends on the direction. The change in the slow axis direction in the phase difference layer is reduced, and the accuracy of these phase difference layers is improved as compared with the prior art.

  Even when the substrate is directly rubbed as in this embodiment, the same effects as in the above-described embodiment can be obtained.

Other Embodiment
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention can be variously combined or modified with the configuration of the above-described embodiment without departing from the spirit of the present invention. Can do.

  That is, in the above-described third and fourth embodiments, the case where a laminate of a plurality of retardation layers is produced by bonding the retardation layers is described. However, the present invention is not limited to this, and a single substrate is formed. The present invention can also be applied to the case where a plurality of retardation layers are produced by sequentially laminating an alignment film and a retardation layer.

  In the third and fourth embodiments described above, the alignment films 62 and 63 are included in the transfer layer to function as a protective layer. However, the present invention is not limited to this, and the alignment films 62 and 63 are formed from the transfer layer. You may make it exclude.

  Moreover, although the case where this invention was applied to a pattern phase difference film and a circularly-polarizing plate was described in the above-mentioned embodiment, this invention is not limited to this but can be widely applied to various other optical films.

DESCRIPTION OF SYMBOLS 1 Pattern phase difference film 2, 64, 65 Base material 3, 62, 63 Alignment film 4, 58, 59 Phase difference layer 5 Molding layer 10 Manufacturing process 11 Supply reel 12, 19 Die 14 Pressure roller 15, 17 Ultraviolet irradiation Device 16 Peeling roller 18 Take-up reel 20 Roll plate 40 Base material 41 Underlayer 42, 44 Inorganic material layer 43 Mask 56 1/4 wavelength plate 51 Image display device 52 Image display panel 53 Optical film 54 Adhesive layer 55 Linearly polarizing plate 55B Optical functional layer 57, 20 Adhesive layer 61 Transfer film R Rubbing roll

Claims (7)

A substrate made of a transparent film material;
An alignment film with a line-shaped uneven shape formed on the substrate;
Formed of a liquid crystal material solidified in a state in which the refractive index anisotropy is maintained by the alignment regulating force of the alignment film, and comprising a retardation layer that imparts a retardation to transmitted light,
The alignment film is
The extension direction of the line-shaped uneven shape is set so as to change in the width direction of the base material so as to correct the change in the slow axis direction in the retardation layer due to the direction of the optical axis in each part of the base material. And an extending direction of the line-shaped unevenness is set. An image display device in which the optical film according to claim 1 is arranged on a viewer side of an image display panel. In the mold for molding by the roll plate that molds the line-shaped uneven shape formed on the peripheral side surface and serves for the production of the alignment film,
Produced by the alignment regulating force of the alignment film according to the direction of the optical axis in each part of the film material that is set so that the extending direction of the line-shaped uneven shape changes in the direction along the rotation axis. An optical film molding die set to correct a change in the slow axis direction in the retardation layer. An alignment film creating step for producing an alignment film with a line-shaped uneven shape on a substrate made of a transparent film material,
A phase difference layer creating step of producing a phase difference layer that solidifies a liquid crystal material while maintaining refractive index anisotropy by the orientation regulating force of the alignment film and gives a phase difference to transmitted light;
The alignment film is
The method for producing an optical film, wherein an extension direction of the line-shaped unevenness is set so as to correct a change in a slow axis direction in the retardation layer depending on an optical axis in each part of the substrate. In the manufacturing method of the mold for molding by the roll plate that molds the line-shaped uneven shape formed on the peripheral side surface and serves for the production of the alignment film,
A rubbing treatment step for producing the line-shaped uneven shape by pressing a rotating rubbing roll against the rotating base material and moving the rotating base material in a direction along the rotation axis of the base material,
The manufacturing method of the shaping mold for optical films which produces the said line-shaped uneven | corrugated shape so that the extension direction of the said line-shaped uneven | corrugated shape changes in the direction along the said rotating shaft. The optical film according to claim 5, wherein the line-shaped uneven shape is produced by changing the inclination of the rubbing roll so that an extending direction of the line-shaped uneven shape is changed in a direction along the rotation axis. Of manufacturing molds for use. The line-shaped concavo-convex shape is produced so that the extending direction of the line-shaped concavo-convex shape changes in the direction along the rotation axis due to a change in the rotation speed of the rubbing roll with respect to the rotation speed of the base material. The manufacturing method of the shaping die for optical films of Claim 5 or Claim 6.

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