JP2014102440A - Optical film, transfer body for optical film, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film capable of improving an appearance of a display screen in an observation in an oblique direction with respect to the normal line of the display screen, and to provide a transfer body for an optical film, and an image display device.SOLUTION: An optical film 3 includes layers of: a substrate comprising a transparent film; an optical functional layer comprising a linearly polarizing plate that functions as a linearly polarizing plate 5; and an optical functional layer comprising a quarter-wave retardation plate that functions as a quarter-wave retardation plate 6. The optical functional layer comprising the quarter-wave retardation plate has a multilayer structure including at least: a retardation layer 9 for a half-wave plate that imparts a retardation corresponding to a half wavelength to transmitted light; and a retardation layer 8 for a quarter-wave plate that imparts a retardation corresponding to a quarter wavelength to the transmitted light. The retardation layer 9 for the half-wave plate and the retardation layer 8 for the quarter-wave plate are formed of the same liquid crystal material and satisfy the relationship represented by 2|θ1|+35°<|θ2|<2|θ1|+45° and 2(R2(550)-20)<R1(550)≤2R2(550).

Description

  The present invention relates to an optical film, an optical film transfer body, and an image display device that are arranged on, for example, an image display panel and reduce reflection of extraneous light by controlling a polarization plane.

  Conventionally, with respect to an image display panel or the like, a method has been proposed in which an optical film is disposed on the exit surface of the image display panel and the reflection of extraneous light is reduced by controlling the polarization plane with the optical film. This optical film is composed of a linearly polarizing plate and a quarter-wave retardation plate, converts external light directed to the panel surface of the image display panel into linearly polarized light by the linear polarizing plate, and then continues with a quarter-wave retardation plate. Convert to circularly polarized light. Here, the extraneous light by the circularly polarized light is reflected by the surface of the image display panel or the like, but the rotation direction of the polarization plane is reversed during this reflection. As a result, contrary to the arrival time, this reflected light is converted from the quarter-wave retardation plate into linearly polarized light in the direction shielded by the linear polarizing plate, and then shielded by the subsequent linear polarizing plate, As a result, the emission to the outside is remarkably suppressed.

  Regarding this optical film, Patent Document 1 and the like describe that this optical film has reverse dispersion characteristics by combining a half-wave plate and a quarter-wave plate to form a quarter-wave retardation plate. A method has been proposed. In the case of this method, an optical film can be formed with reverse dispersion characteristics in a wide wavelength band used for displaying a color image.

  By the way, when such an optical film is disposed on a screen display panel made of an organic EL or the like, when it is observed from an oblique direction with respect to the normal line of the display screen, a color such as bluish or green is observed. It may be visually recognized, and further improvement in the appearance of the display screen is desired.

JP-A-10-68816

  The subject of this invention is providing the optical film which can improve the external appearance of the display screen in the observation from the diagonal direction with respect to the normal line of a display screen, the transfer body for optical films, and an image display apparatus.

  In order to solve the above-mentioned problems, the present inventor has intensively studied, and sets the retardation and slow axis of the retardation layer for a half-wave plate and the retardation layer for a quarter-wave plate within a specific range. The present invention has been completed.

  (1) A substrate made of a transparent film, an optical functional layer of a linear polarizing plate that functions as a linear polarizing plate, and an optical functional layer of a quarter wavelength retardation plate that functions as a quarter wavelength retardation plate Are laminated, and the optical functional layer of the quarter-wave retardation plate provides a retardation layer for a half-wave plate that imparts a half-wave phase difference to the transmitted light, and a quarter of the transmitted light. A quarter-wave plate retardation layer that provides at least a phase difference for a wavelength, and R1 represents retardation in the plane of the half-wave plate retardation layer for transmitted light having a wavelength of 550 nm. (550), R2 (550) is the in-plane retardation of the retardation layer for a quarter-wave plate with respect to transmitted light having a wavelength of 550 nm, and the 1/2 wavelength with respect to the absorption axis of transmitted light of the linearly polarizing plate The slope of the slow axis of the retardation layer for plates is θ1, and the straight line An inclination of a slow axis of the retardation layer for a quarter wavelength plate with respect to an absorption axis of transmitted light of a polarizing plate is θ2, and the retardation layer for a half wavelength plate and the retardation layer for a quarter wavelength plate When the slow axis of each is inclined in the same direction with respect to the absorption axis of the linearly polarizing plate, the half-wave plate retardation layer and the quarter-wave plate retardation layer are And 2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 ° and 2 (R2 (550) −20) <R1 (550) ≦ 2R2 (550). An optical film characterized by satisfying.

(2) The retardation layer for a half-wave plate satisfies a relationship of 12 ° <| θ1 | <17 °,
The optical film according to (1), wherein the retardation layer for a quarter-wave plate satisfies a relationship of 65 ° <| θ2 | <75 °.

  (3) An optical film transfer body having a transfer layer transferred onto an optical functional layer of a linear polarizing plate serving as a linear polarizing plate, and having a phase difference of ½ wavelength in transmitted light A transfer layer having at least a half-wave plate retardation layer to be applied and a quarter-wave plate retardation layer to impart a quarter-wave phase difference to transmitted light; and holding the transfer layer A retardation for the transmitted light having a wavelength of 550 nm and R1 (550) as an in-plane retardation for the transmitted light having a wavelength of 550 nm, and for the transmitted wavelength having a wavelength of 550 nm. The retardation in the plane of the retardation layer is R2 (550), the inclination of the slow axis of the retardation layer for the half-wave plate with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ1, and the retardation of the linear polarizing plate Of the retardation layer for a quarter-wave plate with respect to the absorption axis of transmitted light. The slow axis slope is θ2, and the slow axes of the half-wave plate retardation layer and the quarter-wave plate retardation layer are tilted in the same direction with respect to the absorption axis of the linear polarizing plate. The half-wave plate retardation layer and the quarter-wave plate retardation layer are formed of the same liquid crystal material, and 2 | θ1 | + 35 ° <| θ2 | < 2 | θ1 | + 45 ° and 2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550).

  (4) The half-wave plate retardation layer satisfies a relationship of 12 ° <| θ1 | <17 °, and the quarter-wave plate retardation layer is 65 ° <| θ2 | <75 °. (3) The transfer body for optical films characterized by satisfying the above relationship.

  (5) The optical film transfer body according to (3) or (4), wherein the support is a separator film, and the transfer layer includes an adhesive layer covered with the support.

  (6) Substrate made of a transparent film, an optical functional layer of a linear polarizing plate serving as a linear polarizing plate, and an optical functional layer of a quarter wavelength retardation plate serving as a quarter wavelength retardation plate And the optical functional layer of the ¼ wavelength phase difference plate is an optical functional layer by the transfer layer provided on the optical film transfer body of any one of (3) to (5). An optical film characterized by.

  (7) An image display device comprising an image display panel, wherein the optical film of any one of (1), (2), and (6) is disposed on the image display panel.

  ADVANTAGE OF THE INVENTION According to this invention, the external appearance of the display screen in the observation from the diagonal direction with respect to the normal line of a display screen can be improved.

1 is a diagram showing an image display device 1 according to a first embodiment of the present invention. It is a figure where it uses for description of the optical film 3 provided in the image display apparatus 1 of FIG. It is a basic diagram which shows the manufacturing process of the quarter wavelength phase difference plate 6 contained in the optical film 3 of this invention. It is a figure which shows the image display apparatus 201 which concerns on 2nd Embodiment of this invention. It is a figure which shows the transfer film 220 which concerns on 2nd Embodiment. It is a figure which shows the evaluation result of the display screen of the image display apparatus 1 of the Example by this invention, and the image display apparatus of a comparative example.

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

[First Embodiment]
FIG. 1 is a diagram showing an image display device 1 according to the first embodiment of the present invention. In the image display device 1, the optical film 3 is disposed on the panel surface of the image display panel 2. The image display panel 2 is an organic EL panel having a flexible sheet shape, and displays a desired color image.

  The optical film 3 is an optical film that suppresses reflection of extraneous light arriving at the image display panel 2 by controlling the polarization plane. For this reason, the optical film 3 is configured by laminating a linearly polarizing plate 5 and a quarter-wave retardation plate 6. The optical film 3 is held by being attached to the panel surface of the image display panel 2 by the pressure-sensitive adhesive layer 4 after peeling the separator film (not shown) and exposing the pressure-sensitive adhesive layer 4 by the pressure-sensitive adhesive. The linear polarizing plate 5 and the quarter-wave retardation plate 6 are integrated with each other through the adhesive layer 7.

  The quarter-wave retardation plate 6 includes a portion 8 (referred to as a quarter-wave plate retardation layer) that functions as a quarter-wave plate for imparting a quarter-wave phase difference to transmitted light, and a transmission It is composed of a laminated body with a portion 9 (referred to as a half-wave plate retardation layer) that functions as a half-wave plate that imparts a half-wave phase difference to light. Thereby, the quarter wavelength phase difference plate 6 ensures reverse dispersion characteristics in a wide wavelength band used for displaying a color image, and the optical film 3 sufficiently suppresses reflection of external light in a wide wavelength band.

  Accordingly, in the image display device 1, the quarter-wave plate retardation layer 8, the half-wave plate retardation layer 9, and the linear polarizing plate 5 are sequentially arranged from the display screen side of the image display panel 2. . As shown in FIG. 2, the slow axes of the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 with respect to the absorption axis S of the linearly polarizing plate 5 indicated by arrows (respectively, Are arranged so as to form an angle of θ1 degree and θ2 degree counterclockwise, respectively.

The quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 of the present embodiment are formed of the same liquid crystal material. The quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 are formed to satisfy the following relational expression.
1) 2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °
2) 2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550)

As described above, θ1 and θ2 are inclinations of the slow axes of the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 with respect to the absorption axis of the transmitted light of the linearly polarizing plate 5, respectively. It is. Here, the slow axes of the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 are inclined in the same direction with respect to the absorption axis S of the linear polarizing plate 5. That is, when θ1 is a positive value, θ2 is also a positive value, and when θ1 is a negative value, θ2 is also a negative value.
R1 (550) is in-plane retardation of the half-wave plate retardation layer 9 for transmitted light having a wavelength of 550 nm, and R2 (550) is a quarter wavelength for transmitted light having a wavelength of 550 nm. This is an in-plane retardation of the plate retardation layer 8.

By satisfying the relational expressions 1) and 2) above, when the optical film 3 of this embodiment is disposed on the image display panel 2, the color of the display screen observed from an oblique direction with respect to the normal line of the display screen The taste can be made closer to black, and the appearance of the display screen can be improved.
Further, the quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 satisfy the following relational expression to more specifically realize the optical film 3 having the above effects. it can.
3) 12 ° <| θ1 | <17 °
4) 65 ° <| θ2 | <75 °

The quarter-wave retardation plate 6 is sequentially formed from the image display panel 2 side through the adhesive layer 4, the base material 14, the quarter-wave plate shaping resin layer 10, and the quarter-wave plate alignment film. 11 and a quarter-wave plate retardation layer 8 is provided.
The base material 14 is a transparent film such as TAC (triacetyl cellulose).
The quarter-wave plate shaping resin layer 10 is a shaping resin layer used for shaping a fine uneven shape, and in this embodiment, an ultraviolet curable resin is applied to the shaping resin. In addition, about this ultraviolet curable resin, various resin used for a shaping process, such as an acrylic type, can be applied widely. The quarter-wave plate shaping resin layer 10 has fine irregularities formed on the surface by the shaping treatment, and the quarter-wave retardation plate 6 is formed of the quarter-wave plate shaping resin layer 10. A quarter-wave plate alignment film 11 is formed depending on the surface shape. By forming the quarter-wave plate alignment film 11 on the quarter-wave plate shaping resin layer 10, the alignment layer related to the quarter-wave plate retardation layer 8 is formed.
The quarter-wave plate retardation layer 8 is formed of a liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy, and the quarter-wave retardation plate 6 has an orientation of the liquid crystal material. Patterning is performed by the alignment regulating force of the alignment film 11 for a quarter wavelength plate. The liquid crystal material for forming the quarter-wave plate retardation layer 8 uses the same liquid crystal material as the half-wave plate retardation layer 9. For example, in the following formulas (1) to (13): The compounds represented are used.

Subsequently, the quarter-wave retardation plate 6 is formed on the quarter-wave plate retardation layer 8, the half-wave plate shaping resin layer 12, the half-wave plate alignment film 13, 1. The retardation layer 9 for a two-wavelength plate is sequentially provided.
The half-wave plate shaping resin layer 12 is a shaping resin layer used for shaping a fine uneven shape, and in this embodiment, an ultraviolet curable resin is applied to the shaping resin. The half-wave plate shaping resin layer 12 is formed with fine irregularities on the surface by the shaping treatment, and the quarter-wave retardation plate 6 is formed of the half-wave plate shaping resin layer 12. A half-wave plate alignment film 13 is formed depending on the surface shape. By forming the half-wave plate orientation film 13 on the half-wave plate shaping resin layer 12, the orientation layer related to the half-wave plate retardation layer 9 is formed.
The half-wave plate retardation layer 9 is formed of a liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy, and the quarter-wave plate 6 has an orientation of the liquid crystal material. Patterning is performed by the alignment regulating force of the alignment film 13 for a half-wave plate. Moreover, the liquid crystal material which forms the retardation layer 9 for 1/2 wavelength plates is using the same liquid crystal material as the above-mentioned retardation layer 8 for 1/4 wavelength plates, for example, following formula (1)- The compound represented by (13) is used.

  The fine concavo-convex shape relating to the alignment film 13 for half-wave plates and the alignment film 11 for ¼-wave plates is formed by a line-shaped uneven shape extending in one direction, and extends in this one direction. The directions to be formed are such that the angles are respectively θ1 degrees and θ2 degrees counterclockwise with respect to the absorption axis S of the linearly polarizing plate 5.

  In the linear polarizing plate 5, the lower surface side of the base material 15 made of a transparent film such as TAC (triacetyl cellulose) is saponified, and then the optical functional layer 16 is disposed. In addition, the base material 15 is replaced with poly (meth) acrylate methyl, poly (meth) acrylate butyl, (meth) acrylate methyl- (meth) acrylate copolymer, (meth) acrylate- 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 16 is a part that bears an optical function as a linear polarizing plate, and is produced, for example, by adsorbing and orienting iodine compound molecules on a film material of polyvinyl alcohol (PVA).

〔Manufacturing process〕
FIG. 3 is a schematic diagram showing a manufacturing process 20 of the quarter wavelength phase difference plate 6. In the manufacturing process 20, the base material 14 is provided by a roll, and the base material 14 is supplied from a supply reel 21. In the manufacturing process 20, the coating solution of the ultraviolet curable resin 10 is applied to the base material 14 by the die 22. In this manufacturing process 20, the roll plate 30 is a cylindrical shaping mold in which the concavo-convex shape of the quarter-wave plate alignment film 11 of the quarter-wave retardation plate 6 is formed on the peripheral side surface. . In the manufacturing process 20, the base material 14 coated with the ultraviolet curable resin is pressed against the peripheral side surface of the roll plate 30 by the pressure roller 24, and the ultraviolet curable resin is obtained by irradiating the ultraviolet ray with the ultraviolet irradiation device 25 made of a high-pressure mercury lamp. Harden. Thereby, the manufacturing process 20 transfers the uneven | corrugated shape formed in the surrounding side surface of the roll plate 30 to the base material 14. FIG. Thereafter, the substrate 14 is peeled off from the roll plate 30 together with the ultraviolet curable resin 10 cured by the peeling roller 26, and a liquid crystal material is applied by the die 29. Thereafter, the liquid crystal material is cured by irradiating with ultraviolet rays from the ultraviolet irradiating device 27, thereby creating a configuration relating to the quarter-wave plate retardation layer 8.

  Subsequently, in this step 20, the base material 14 is transported to the die 32 by the transport roller 31, and the coating solution of the ultraviolet curable resin 12 is applied onto the quarter-wave plate retardation layer 8 of the base material 14 by the die 32. Apply. In this manufacturing process 20, the roll plate 40 is a cylindrical shaping mold in which the concavo-convex shape related to the alignment film 13 for the half-wave plate of the quarter-wave retardation plate 6 is formed on the peripheral side surface. . In the manufacturing process 20, the base material 14 coated with the ultraviolet curable resin is pressed against the peripheral side surface of the roll plate 40 by the pressure roller 34, and the ultraviolet curable resin is applied by irradiating the ultraviolet rays with the ultraviolet irradiation device 35 made of a high-pressure mercury lamp. Harden. Thereby, the manufacturing process 20 transfers the uneven | corrugated shape formed in the surrounding side surface of the roll plate 40 to the base material 14. FIG. Thereafter, the substrate 14 is peeled off from the roll plate 40 integrally with the ultraviolet curable resin 12 cured by the peeling roller 36, and a liquid crystal material is applied by the die 39. Thereafter, the liquid crystal material is cured by ultraviolet irradiation by the ultraviolet irradiation device 37, and the configuration relating to the retardation layer 9 for half-wave plate is created by these.

  In the manufacturing process, the adhesive layer 4 is subsequently arranged integrally with the separator film according to the adhesive layer 4, and then integrated with the linearly polarizing plate 5 created in a separate process to produce the optical film 3.

As described above, the optical film 3 of the present embodiment satisfies the relational expressions 1) and 2), and is formed of the same liquid crystal material with the retardation layer 8 for the quarter-wave plate and the half-wave plate position. Since the phase difference layer 9 is formed, the color of the display screen observed from an oblique direction with respect to the normal line of the display screen can be brought close to black when placed on the image display panel 2, and the appearance of the display screen Can be improved.
Moreover, since the optical film 3 forms the retardation layer 8 for quarter wavelength plates and the retardation layer 9 for half wavelength plates so as to satisfy the relational expressions of the above formulas 3) and 4), The optical film 3 having the above effects can be realized more specifically.

[Second Embodiment]
FIG. 4 is a diagram showing an image display device 201 according to the present embodiment in comparison with FIG. FIG. 5 is a view showing a transfer film 220 according to this embodiment. Note that, in the following description and drawings, the same reference numerals or the same reference numerals are given to the portions that perform the same functions as those in the first embodiment described above, and overlapping descriptions will be omitted as appropriate.
The image display device 201 according to the second embodiment is different from the image display device 1 according to the first embodiment in that a quarter-wave retardation plate 206 is formed by the transfer layer of the transfer film 220.
As shown in FIG. 4, in the optical film 203, the quarter-wave retardation plate 206 and the linear polarizing plate 5 are integrated through an adhesive layer 207, and a transfer method is applied to the integration process. .

  Here, in the transfer method, 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 layer by laminating the layers, according to the process, demand, etc., the layer formed on the support is finally deposited on the substrate (the substrate to be transferred) on which the layer is to be laminated. In this method, a desired layer is formed on the substrate by peeling and removing the support.

  In this embodiment, the layer configuration related to the quarter-wave retardation plate 206 is laminated on the linearly polarizing plate 5 by a transfer method. Therefore, the substrate to be transferred is the linearly polarizing plate 5, and the layer (transfer layer) used for transfer is a quarter-wave plate shaping resin layer 10, a quarter-wave plate alignment film 11, and a quarter wavelength. It is a laminate of a plate retardation layer 8, a half-wave plate shaping resin layer 12, a half-wave plate alignment film 13, and a half-wave plate retardation layer 9.

  FIG. 5 is a diagram showing a configuration of a transfer film 220 as the transfer body. The transfer film 220 is formed on the support substrate 221 in order, the quarter-wave plate shaping resin layer 10 according to the quarter-wave retardation plate 206, and the quarter-wave plate alignment film 11, 1/4. A retardation plate 8 for a wavelength plate, a shaping resin layer 12 for a half-wave plate, an alignment film 13 for a half-wave plate, and a retardation layer 9 for a half-wave plate are provided.

  Here, the support substrate 221 detachably supports a layer (transfer layer) to be transferred, and after the transfer layer is bonded and laminated on the transfer substrate, it is appropriately peeled and removed as needed. It is a substrate. In this embodiment, a PET (Polyethylene terephthalate) film, which is a transparent film material, is applied, whereby the transfer film 220 is configured to be able to inspect optical characteristics. The PET film is corona-treated, thereby appropriately setting the adhesion between the PET film and a release layer described later. The support base material 221 may have a sheet shape as a whole. The support substrate 221 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. In addition, the thickness of the support base material 221 is 20 to 100 μm. In the case where the peelability from the transfer layer is insufficient, a release layer that promotes peeling is provided on the support base material 221 on the transfer layer side.

  For the release layer, a material having relatively high adhesion to the support substrate 221 (low peelability) and low adhesion to the transfer layer (high peelability) can be applied. In this embodiment, since the lowermost layer of the transfer layer is the quarter-wave plate shaping resin layer 10 made of an ultraviolet curable resin, for example, a silicon resin (organosilicon-based) is used for the support substrate 221 described above. 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. In this embodiment, a release layer made of melamine resin is provided on the support substrate 221 made of the above-described PET film, and the wettability of the ultraviolet curable resin provided on the release layer with respect to the coating solution is ensured.

  Instead of providing a release layer made of melamine resin on the corona-treated PET film in this way, a PET film that has not been surface-treated at all may be applied to the support substrate to omit the release layer. Alternatively, a release layer may be omitted by applying a TAC film without a so-called permeation layer called a nonsol to the support substrate. In this way, the configuration can be simplified.

  Incidentally, when the peelability by the release layer is insufficient, a release layer may be provided between the support substrate 221 and the release layer, and this 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 is used. The thickness of the release layer is usually about 1 to 10 μm. Further, the release layer may be provided on the support substrate 221 or may be provided on the release layer.

  The quarter-wave plate shaping resin layer 10 is prepared by applying an ultraviolet curable resin coating solution on the support substrate 221 or on the release layer formed on the support substrate 221. The quarter-wave plate alignment film 11 is prepared by coating, and the quarter-wave plate alignment film 11 is applied to a quarter-wave plate using a molding die (roll plate) in which a fine uneven shape for molding is formed on the peripheral side surface. The mold resin layer 10 is formed by a shaping process. The quarter-wave plate retardation layer 8 is formed by applying a liquid crystal material on the quarter-wave plate alignment film 11 and curing it.

  The half-wave plate shaping resin layer 12 is formed by applying a coating solution of an ultraviolet curable resin on the quarter-wave plate retardation layer 8, and the half-wave plate orientation Similarly to the alignment film 11 for a quarter wavelength plate, the film 13 is formed by molding the half-wave plate molding resin layer 12 using a molding die. The half-wave plate retardation layer 9 is formed by applying a liquid crystal material on the half-wave plate alignment film 13 and curing it. Thus, in the transfer body, the quarter wavelength plate shaping resin layer 10, the quarter wavelength plate alignment film 11, and the quarter wavelength plate position are the layer configurations related to these quarter wavelength retardation plates. The retardation layer 8, the half-wave plate shaping resin layer 12, the half-wave plate alignment film 13, and the half-wave plate retardation layer 9 are transfer layers used for transfer.

  Further, the transfer film 220 is provided with an adhesive layer 207 and a separator film 223 on the transfer layer according to the layer configuration related to the quarter-wave retardation plate 206.

Here, the adhesive layer 207 is a layer for adhering the transfer layer and the substrate to be transferred. Depending on the material of the transfer layer and the material of the substrate to be transferred, a material having high adhesion is applied to both. In this embodiment, cellulose (fiber) based resins such as acetyl cellulose (cellulose acetate), nitrocellulose (cellulose nitrate or nitrified cotton), cellulose acetate propionate, poly (meth) methyl acrylate, poly (meta) ) Acrylic resin such as butyl acrylate, methyl (meth) acrylate- (meth) butyl acrylate copolymer, methyl (meth) acrylate-styrene copolymer, urethane resin, polyester resin, vinyl chloride-vinyl acetate Materials such as polymers, ionomers, natural or synthetic rubbers are used. The thickness of the adhesive layer is about 1 to 30 μm.
The adhesive layer 207 may use an ultraviolet curable resin. In this case, the thickness of the optical film can be further reduced.

  The separator film 223 is a release sheet that covers the surface of the adhesive layer 207 so that it can be released. The separator film 223 is provided to prevent the adhesive layer 207 from being exposed and causing unnecessary adhesion to unnecessary articles, and is peeled and removed immediately before transfer.

  As described above, in this embodiment, even when the quarter-wave retardation plate 206 is formed of a transfer layer, the same effects as those of the first embodiment can be obtained. Moreover, since the optical film 203 of this embodiment has a quarter-wave retardation plate 206 attached to the linearly polarizing plate 5 with a transfer layer, the substrate 14 is omitted as compared with the optical film 3 of the first embodiment. The entire thickness of the optical film 203 can be reduced.

[Evaluation of display screen of image display device]
Next, the evaluation results of the display screens of the image display device 1 (Example) provided with the optical film 3 according to the present invention and the image display device (Comparative Example) provided with an optical film different from the present invention will be described. .
FIG. 6 is a diagram showing the evaluation results of the display screens of the image display device 1 of the example according to the present invention and the image display device of the comparative example.

In FIG. 6, as the liquid crystal material for forming the retardation layer 9 for half-wave plates and the retardation layer 8 for quarter-wave plates, the compound described in the above formula (11) is used.
The evaluation of chromaticity in FIG. 6 indicates the reflectance and chromaticity of light that is incident from a direction inclined by 8 ° in the horizontal direction with respect to the normal line of the display screen of the image display device and is regularly reflected on the display screen. ing. For the measurement of chromaticity, JASCO Corporation (V-7100) was used. The chromaticity is measured based on a color display method (Japanese Industrial Standard: JISZ8729) using the L * a * b * color system. Here, a * and b * in FIG. 6 indicate the degree of color in the corresponding color, and a * indicates the red direction in the plus direction, the green direction in the minus direction, and b * The plus direction indicates the yellow direction and the minus direction indicates the blue direction. Moreover, the evaluation of the hue in the oblique direction in FIG. 6 is a sensory evaluation based on the visual recognition of the measurer measured from the oblique direction of the display screen.
In-plane retardation (R1 (550), R2 (550)) of each retardation layer was measured using KOBRA-WR manufactured by Oji Scientific Instruments.
In the evaluation, an organic EL panel of a mobile phone (Samsung, Galaxy GS III) was used as an image display panel used for each image display device. Moreover, each evaluation of the above-mentioned chromaticity and color was performed in a state where no image was displayed on the display screen of the image display panel.

  In the image display device 1 of Example 1, the retardation layer 9 for a half-wave plate has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 is θ1 = 15 °, and the wavelength is 550 nm. In-plane retardation with respect to transmitted light is R1 (550) = 250 nm. The quarter-wave plate retardation layer 8 has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 is θ2 = 73 °, and has in-plane retardation with respect to the transmitted light having a wavelength of 550 nm. R2 (550) = 140 nm.

  In the image display device 1 of Example 2, the half-wave plate retardation layer 9 has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 is θ1 = 15 °, and the wavelength is 550 nm. In-plane retardation with respect to transmitted light is R1 (550) = 250 nm. The quarter-wave plate retardation layer 8 has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 is θ2 = 73 °, and has in-plane retardation with respect to the transmitted light having a wavelength of 550 nm. R2 (550) = 130 nm.

  In the image display device 1 of Example 3, the half-wave plate retardation film 9 has a slow axis tilt of θ1 = 13 ° with respect to the absorption axis of transmitted light of the linearly polarizing plate 5 and a wavelength of 550 nm. In-plane retardation with respect to transmitted light is R1 (550) = 240 nm. The quarter-wave plate retardation film 8 has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 of θ2 = 69 °, and has in-plane retardation with respect to the transmitted light having a wavelength of 550 nm. R2 (550) = 120 nm.

  In the image display device 1 of Example 4, the half-wave plate retardation film 9 has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 is θ1 = 15 °, and the wavelength is 550 nm. In-plane retardation with respect to transmitted light is R1 (550) = 240 nm. The quarter-wave plate retardation layer 8 has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate 5 is θ2 = 71 °, and has in-plane retardation with respect to the transmitted light having a wavelength of 550 nm. R2 (550) = 121 nm.

  On the other hand, in the image display device of Comparative Example 1, the retardation layer for a half-wave plate has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ1 = 15 °, and the transmission at 550 nm. In-plane retardation with respect to light is R1 (550) = 240 nm. In addition, the retardation layer for a quarter wavelength plate has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ2 = 75 °, and an in-plane retardation for the transmitted light having a wavelength of 550 nm is R2 ( 550) = 120 nm.

  In the image display device of Comparative Example 2, the half-wave plate retardation layer has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ1 = 15 °, and is in-plane with respect to the transmitted light of 550 nm. The retardation of R1 (550) = 240 nm. In addition, the retardation layer for a quarter wavelength plate has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ2 = 73 °, and an in-plane retardation for the transmitted light having a wavelength of 550 nm is R2 ( 550) = 115 nm.

  In the image display device of Comparative Example 3, the half-wave plate retardation layer has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ1 = 15 °, and is in-plane with respect to the transmitted light of 550 nm. The retardation of R1 (550) = 240 nm. In addition, the retardation layer for a quarter wavelength plate has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ2 = 75 °, and an in-plane retardation for the transmitted light having a wavelength of 550 nm is R2 ( 550) = 140 nm.

  In the image display device of Comparative Example 4, the half-wave plate retardation layer has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ1 = 17 °, and is in-plane with respect to the transmitted light of 550 nm. The retardation of R1 (550) = 230 nm. In addition, the retardation layer for a quarter wavelength plate has an inclination of the slow axis with respect to the absorption axis of the transmitted light of the linear polarizing plate is θ2 = 73 °, and an in-plane retardation for the transmitted light having a wavelength of 550 nm is R2 ( 550) = 140 nm.

  In the image display device of Comparative Example 5, the retardation layer for a half-wave plate is omitted, and the retardation layer for the quarter-wave plate has an inclination of the slow axis with respect to the absorption axis of transmitted light of the linear polarizing plate is θ2. = 45 °, and in-plane retardation with respect to transmitted light having a wavelength of 550 nm is R2 (550) = 142 nm.

As shown in FIG. 6, the image display devices according to Comparative Example 1 and Comparative Example 3 were greenish in the color of the display screen observed from an oblique direction with respect to the normal line of the display screen. Moreover, the image display apparatus which concerns on the comparative example 2 and the comparative example 4 had a yellowish tint of the display screen. Further, in the image display device according to Comparative Example 5, the color of the display screen was bluish.
On the other hand, the color of the display screen of the image display device 1 according to each of the examples (1 to 4) was almost black. Therefore, the image display device 1 of the present invention can emphasize the blackness of the display screen and improve the appearance of the display screen as compared with the image display device of the comparative example.

Here, Comparative Example 1 satisfies the above-described relational expression 2) of the quarter-wave plate retardation layer 8 and the half-wavelength retardation layer 9, but does not satisfy the relational expression 1). 2 satisfies the relational expression 1) but does not satisfy the relational expression 2). Comparative Example 3 does not satisfy both of the relational expressions 1) and 2), and Comparative Example 4 satisfies the relational expression 1) but does not satisfy the relational expression 2).
On the other hand, the image display device 1 according to each embodiment satisfies both of the relational expressions 1) and 2). By satisfying all the relational expressions 1) and 2), the image display apparatus 1 is satisfied. It was confirmed that the appearance of the display screen observed from an oblique direction with respect to the normal of the display screen can be improved.
In addition, the image display device 1 of each example also satisfies the above-described relational expressions 3) and 4) of the quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9. Specifically, it was also confirmed that the optical film 3 according to the present invention can be realized.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above. However, the present invention is not limited to the scope of the present invention, and various combinations of the above-described embodiments, and further the configuration of the above-described embodiments. Can be variously changed.

(1) In the first embodiment, the quarter-wave retardation plate 6 is formed on the upper surface of the base material 14 in order, the quarter-wave plate shaping resin layer 10, the quarter-wave plate alignment film 11, An example of a configuration in which a quarter-wave plate retardation layer 8, a half-wave plate shaping resin layer 12, a half-wave plate alignment film 13, and a half-wave plate retardation layer 9 are formed. Although shown, it is not limited to this.
For example, on the lower surface of the base material 14, the half-wave plate shaping resin layer 12, the half-wave plate alignment film 13, the half-wave plate retardation layer 9, and the quarter-wave plate You may make it the structure which formed the shaping resin layer 10, the alignment film 11 for 1/4 wavelength plates, and the phase difference layer 8 for 1/4 wavelength plates. In this case, the quarter-wave retardation plate needs to be provided with the adhesive layer 7 on the upper surface of the substrate 14 and the adhesive layer 4 on the lower surface of the quarter-wave plate retardation layer 8.
Further, a half-wave plate shaping resin layer 12, a half-wave plate alignment film 13, and a half-wave plate retardation layer 9 are sequentially formed on the upper surface of the substrate 14. A quarter-wave plate shaping resin layer 10, a quarter-wave plate alignment film 11, and a quarter-wave plate retardation layer 8 may be sequentially formed on the lower surface of the plate.

(2) In 2nd Embodiment, although the transfer layer showed the example which peels the support base material 221 and affixes on the image display panel 2, it is not limited to this, The separator film 223 is peeled and an image display panel is shown. 2 may be attached.
In this case, a half-wave plate shaping resin layer, a half-wave plate alignment film, a half-wave plate retardation layer, a quarter-wave plate shaping resin layer, and a quarter-wave plate It is necessary to form a transfer body in which an alignment film and a quarter-wave plate retardation layer are laminated in this order on a support substrate.

(3) In each embodiment, the case where the alignment film is formed by the shaping process has been described. However, the present invention is not limited to this, and the present invention can also be applied to the case where the alignment film is formed by a photo-alignment technique.

(4) In each embodiment, the adhesive layer 7 is provided on the transfer layer side, and the linear polarizing plate 5 and the transfer layer are integrated by the adhesive layer 7. However, the present invention is not limited to this. Instead, the adhesive layer 7 may be provided on the linearly polarizing plate 5 side.

(5) In each embodiment, although the case where the shaping process is performed using a roll plate has been described, the present invention is not limited thereto, and can be widely applied to the case where a shaping process is performed using a flat plate.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 2 Image display panel 3, 203 Optical film 4, 7 Adhesion layer 5 Linearly polarizing plate 6, 206 1/4 wavelength phase difference plate 8 1/2 wavelength plate phase difference layer 9 1/4 wavelength plate position Phase difference layer 10 1/4 wavelength plate shaping resin layer 11 1/4 wavelength plate alignment film 12 1/2 wavelength plate shaping resin layer 13 1/2 wavelength plate alignment films 14, 15 Base material 16 Optical function Layer 220 Transfer film 221 Support substrate 223 Separator film 20 Manufacturing process 21 Supply reels 22, 29, 32, 39 Dies 24, 34 Pressure rollers 25, 27, 35, 37 UV irradiation devices 26, 36 Peeling rollers 30, 40 Roll plate 31 Conveying roller

Claims (7)

A substrate made of a transparent film;
An optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate;
The optical function layer of the 1/4 wavelength phase difference plate serving as the 1/4 wavelength phase difference plate is laminated,
The optical functional layer of the ¼ wavelength phase difference plate includes a phase difference layer for ½ wavelength plate that imparts a phase difference of ½ wavelength to the transmitted light, and a phase difference of ¼ wavelength to the transmitted light. A multilayer structure having at least a quarter-wave plate retardation layer that provides
The retardation in the plane of the half-wave plate retardation layer for the transmitted light having a wavelength of 550 nm is R1 (550), and the retardation in the plane of the quarter-wave plate retardation layer for the transmitted light having a wavelength of 550 nm is R1 (550). The retardation is R2 (550), the inclination of the slow axis of the retardation layer for the half-wave plate with respect to the absorption axis of the transmitted light of the linear polarizer is θ1, and the transmission axis of the transmitted light of the linear polarizer is with respect to the absorption axis. The inclination of the slow axis of the quarter-wave plate retardation layer is θ2, and each slow axis of the half-wave plate retardation layer and the quarter-wave plate retardation layer is the linearly polarized light. When it is inclined in the same direction with respect to the absorption axis of the plate,
The half-wave plate retardation layer and the quarter-wave plate retardation layer are
Formed from the same liquid crystal material,
2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °,
2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550)
An optical film characterized by The retardation layer for a half-wave plate is
Satisfies the relationship of 12 ° <| θ1 | <17 °,
The quarter-wave plate retardation layer comprises:
Satisfying the relationship of 65 ° <| θ2 | <75 °,
The optical film according to claim 1. A transfer body for an optical film having a transfer layer transferred onto an optical functional layer of a linear polarizing plate that functions as a linear polarizing plate,
A retardation layer for a half-wave plate that imparts a phase difference of ½ wavelength to transmitted light, and a retardation layer for a quarter-wave plate that imparts a phase difference of ¼ wavelength to transmitted light Having at least a transfer layer;
A support for holding the transfer layer,
The retardation in the plane of the half-wave plate retardation layer for the transmitted light having a wavelength of 550 nm is R1 (550), and the retardation in the plane of the quarter-wave plate retardation layer for the transmitted light having a wavelength of 550 nm is R1 (550). The retardation is R2 (550), the inclination of the slow axis of the retardation layer for the half-wave plate with respect to the absorption axis of the transmitted light of the linear polarizer is θ1, and the transmission axis of the transmitted light of the linear polarizer is with respect to the absorption axis. The inclination of the slow axis of the quarter-wave plate retardation layer is θ2, and each slow axis of the half-wave plate retardation layer and the quarter-wave plate retardation layer is the linearly polarized light. When it is inclined in the same direction with respect to the absorption axis of the plate,
The half-wave plate retardation layer and the quarter-wave plate retardation layer are
Formed from the same liquid crystal material,
2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °,
2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550)
An optical film transfer body characterized by the above. The retardation layer for a half-wave plate is
Satisfies the relationship of 12 ° <| θ1 | <17 °,
The quarter-wave plate retardation layer comprises:
Satisfying the relationship of 65 ° <| θ2 | <75 °,
The transfer member for an optical film according to claim 3. The support is a separator film;
The transfer layer comprises an adhesive layer covered by the support;
The transfer body for optical films according to claim 3 or 4, wherein A substrate made of a transparent film;
An optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate;
The optical function layer of the 1/4 wavelength phase difference plate serving as the 1/4 wavelength phase difference plate is laminated,
The optical functional layer of the quarter-wave retardation plate is an optical functional layer by the transfer layer provided on the optical film transfer body according to any one of claims 3 to 5,
An optical film characterized by It has an image display panel,
Arranging the optical film according to any one of claims 1, 2, or 6 on the image display panel,
An image display device characterized by the above.

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