JP2017097379A - Optical film, transfer body for optical film and image display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film capable of improving the outside appearance of a display screen being observed obliquely to a normal to the display screen.SOLUTION: An optical film 3 has an optical function layer of a linear polarization plate 5, a retardation layer 9 for a 1/2-wavelength plate, a retardation layer 8 for a 1/4-wavelength plate, and a positive C plate 17 laminated in order. Here, -140nm≤Rth≤-40nm holds for a thickness-directional retardation Rth of the positive C plate 17, 7°<|θ1|<17°and 59°<|θ2|<76° hold for an inclination θ1 of a phase delay axis of the retardation layer 9 for the 1/2-wavelength plate and an inclination θ2 of the retardation layer 8 for the 1/4-wavelength plate, and 2|θ1|+35°<|θ2|<2|θ1|+45° and 2(R2(550)-20)<R1(550)≤2R2(550) hold for the retardation R1 in a plane of the retardation layer 9 for the 1/2-wavelength plate for transmitted light of 550 nm in wavelength and the retardation R2 in a plane of the retardation layer 8 for the 1/4-wavelength plate.SELECTED DRAWING: Figure 1

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 an image display panel made of 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 greenish. 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.

  The present inventor has made extensive studies to solve the above problems, and has come up with the idea that a positive C plate having a retardation in the thickness direction within a predetermined range is laminated, and has completed the present invention.

(1) an optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate, a retardation layer for a ½ wavelength plate that imparts a phase difference of ½ wavelength to transmitted light, and 1 / A quarter-wave plate retardation layer for providing a phase difference for four wavelengths and a positive C plate having an in-plane refractive index smaller than the refractive index in the thickness direction are sequentially stacked, and the positive C plate is in the thickness direction. The retardation Rth of the film satisfies −140 nm ≦ Rth ≦ −40 nm, and the half-wave plate retardation layer and the quarter-wave plate retardation layer have an absorption axis or transmission of the transmitted light of the linearly polarizing plate. The inclination of the slow axis of the half-wave plate retardation layer relative to the axis is θ1, and the slow axis of the quarter-wave plate retardation layer relative to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate 7 ° <| θ1 | <17 °, 59 ° <| θ2 | <76 ° R1 represents the retardation in the plane of the half-wave plate retardation layer for the transmitted light having a wavelength of 550 nm, and the in-plane retardation layer for the quarter-wave plate for the transmitted light having a wavelength of 550 nm. When the retardation is R2, 2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °, and 2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550) An optical film characterized by

(2) In the retardation layer for a quarter-wave plate and the retardation layer for a half-wave plate, the retardation in the in-plane direction (R1 (550), R2 (550)) is 230 nm ≦ R1 ( 550) ≦ 276 nm, 110 nm ≦ R2 (550) ≦ 150 nm satisfying the relational expression, the optical film as described in (1).

(3) The standard deviation (3σ) and the Y coordinate value standard deviation (3σ) of the x coordinate value of the reflected chromaticity measured from all directions at a polar angle of 60 ° are 0.0299 or less, and the x of the reflected chromaticity is x (1) or (2), wherein an average value of coordinates is 0.3049 or more and 0.3186 or less, and an average value of y coordinates of the reflection chromaticity is 0.3493 or more and 0.3531 or less. The optical film described in 1.

(4) The quarter-wave plate retardation layer and the half-wave plate retardation layer are formed of the same liquid crystal material. The optical film as described.

(5) the positive C plate is formed of a liquid crystal compound;
The optical film according to any one of (1) to (4).

(6) An image display device comprising an image display panel, wherein the optical film according to any one of (1) to (5) is disposed on the image display panel.

(7) 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 half-wave plate retardation layer to be applied; a quarter-wave plate retardation layer to impart a phase difference of ¼ wavelength to transmitted light; and an in-plane refractive index greater than a refractive index in the thickness direction. A transfer layer in which small positive C plates are sequentially laminated, and a support that holds the transfer layer, and the positive C plate has a thickness direction retardation Rth of −140 nm ≦ Rth ≦ −40 nm, The retardation layer for half-wave plate and the retardation layer for quarter-wave plate are the slow axis of the retardation layer for half-wave plate with respect to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate. The inclination of the light is θ1, and the light transmission axis of the linearly polarizing plate is in front of the absorption axis or transmission axis. When the inclination of the slow axis of the retardation layer for a quarter-wave plate is θ2, the relationship of 7 ° <| θ1 | <17 °, 59 ° <| θ2 | <76 ° is satisfied, and the wavelength is 550 nm. R1 is the in-plane retardation of the retardation layer for a half-wave plate with respect to transmitted light of R2, and R2 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. 2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °, satisfying the relationship of 2 (R2 (550) −20) <R1 (550) ≦ 2R2 (550) Transcript.

(8) The retardation layer (R1 (550), R2 (550)) in the in-plane direction of each of the retardation layer for a quarter wavelength plate and the retardation layer for a half wavelength plate is 230 nm ≦ R1 ( 550) ≦ 276 nm, 110 nm ≦ R2 (550) ≦ 150 nm satisfying the relational expression, the transfer member for optical film according to (7),

(9) The x-coordinate standard deviation (3σ) and Y-coordinate standard deviation (3σ) of the reflected chromaticity measured from all directions at a polar angle of 60 ° are 0.0299 or less, and the x of the reflected chromaticity is x (7) or (8), wherein an average value of coordinates is 0.3049 or more and 0.3186 or less, and an average value of y coordinates of the reflection chromaticity is 0.3493 or more and 0.3531 or less. The transfer body for optical films as described in 2.

(10) The transfer member for an optical film according to any one of (7) to (9), wherein the positive C plate is formed of a liquid crystal compound.

(11) The optical film according to any one of (7) to (10), wherein the support is a separator film, and the transfer layer includes an adhesive layer covered with the support. Transcript for transfer.

(12) A substrate made of a transparent film, an optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate, and an optical functional layer of a ¼ wavelength phase difference plate that functions as a ¼ wavelength phase difference plate And 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 (6) to (10). An optical film characterized by being.

(13) An image display device comprising an image display panel, wherein the optical film according to (12) 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 an approximate line figure showing a manufacturing process of quarter wave phase difference plate 6 contained in optical film 3 of the present 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. It is a figure which shows the evaluation result of the chromaticity of the optical film of the Example by this invention, and the optical film of a comparative example. It is a figure which shows the evaluation result of the reflective luminance of the optical film of the Example by this invention, and the optical film 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 image display panel 2 is not limited to an organic EL panel, and a reflective liquid crystal panel or the like can be applied.

  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 laminate of a portion 9 (referred to as a retardation layer for a half-wave plate) that functions as a half-wave plate that imparts a phase difference of 1/2 wavelength to the light, and a positive C plate . 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.
Here, the positive C plate refers to a film having an in-plane refractive index smaller than the refractive index in the thickness direction, and the negative C plate is formed to have an in-plane refractive index larger than the refractive index in the thickness direction. Refers to film.

  As a result, in the image display device 1, from the display screen side of the image display panel 2, the positive C plate 17, the quarter-wave plate retardation layer 8, the half-wave plate retardation layer 9, and the linear polarization plate are sequentially arranged. 5 is arranged. Further, as shown in FIG. 2, the retardation of the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 with respect to the absorption axis S or the transmission axis of the linearly polarizing plate 5 indicated by an arrow. The axes (respectively indicated by arrows) are arranged so as to form angles of θ1 degrees and θ2 degrees counterclockwise, respectively.

The positive C plate of this embodiment is formed so that the retardation Rth in the thickness direction satisfies the following relational expression.
1) −140 nm ≦ Rth ≦ −40 nm
Further, the quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 of the present embodiment are formed so as to satisfy the following relational expression.
2) 7 ° <| θ1 | <17 °
3) 59 ° <| θ2 | <76 °

Here, as described above, θ1 and θ2 are the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer, respectively, with respect to the absorption axis S of the transmitted light of the linearly polarizing plate 5 or the transmission axis. 8 is the inclination of the slow axis. 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 or the transmission axis of the linearly polarizing plate 5. To do. 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. Further, when θ1 is an inclination of the slow axis with respect to the absorption axis of the linearly polarizing plate 5, θ2 also indicates an inclination of the slow axis with respect to the absorption axis of the linearly polarizing plate 5, and conversely, θ1 is transmitted through the linearly polarizing plate 5. When the inclination of the slow axis with respect to the axis is taken, θ2 also indicates the inclination of the slow axis with respect to the transmission axis of the linearly polarizing plate 5.
By satisfying the above relational expressions 1) to 3), the optical film 3 of the present embodiment has a display screen that is observed from an oblique direction with respect to the normal line of the display screen when placed on the image display panel 2. The color can be brought close to black like the color in the front direction, 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. In this case, the quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 must be formed of the same liquid crystal material.
4) 2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °
5) 2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550)
Here, R1 (550) is an in-plane retardation of the half-wave plate retardation layer 9 for transmitted light having a wavelength of 550 nm, and R2 (550) is 1/4 for transmitted light having a wavelength of 550 nm. This is in-plane retardation of the phase difference layer 8 for the wave plate.

The quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 have a function as the quarter-wave retardation plate 6, and therefore have a retardation (R1) in the respective in-plane directions. (550), R2 (550)) preferably satisfies the following relational expression.
6) 230 nm ≦ R1 (550) ≦ 276 nm
7) 110 nm ≦ R2 (550) ≦ 150 nm

The quarter-wave retardation plate 6 includes a positive C plate 17, a quarter-wave plate retardation layer 8, and a half-wave plate retardation layer 9 via the adhesive layer 4 from the image display panel 2 side. It is provided in order.
The positive C plate 17 is a rod-shaped liquid crystal compound solidified (cured) in a state where the in-plane refractive index is smaller than the refractive index in the thickness direction, for example, a liquid crystal compound represented by the following chemical formula (5) with respect to the substrate. Are formed on the substrate 14 by adding additives that are vertically oriented. Specifically, by using the additives described in JP-A-2005-173410, JP-A-2006-57051, and JP-A-2006-106662, the liquid crystal can be vertically aligned without using a special alignment film. it can. Furthermore, 4% of BASF Irgacure 184 or Irgacure 907 as an initiator is added to the liquid crystal material and dissolved to a solid content concentration of 25% using MIBK, cyclohexanone, or a mixed solvent of MIBK and cyclohexanone. Is made. The substrate is coated with a Miya bar to obtain a drying process for 3 minutes at a setting of 110 ° C., and is oriented and fixed by ultraviolet curing in a nitrogen atmosphere.
The base material 14 is a transparent film such as TAC (triacetyl cellulose).

The quarter-wave retardation plate 6 is provided with a quarter-wave plate shaping resin layer 10 and a quarter-wave plate retardation layer 8 in this order on the positive C plate 17.
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. On the surface of the quarter-wave plate shaping resin layer 10, a fine uneven shape, that is, a quarter-wave plate orientation film shape 11 is formed by a shaping treatment.
The quarter-wave plate retardation layer 8 is formed of a rod-like liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy, and the orientation of the liquid crystal material is changed to a quarter-wave plate orientation film shape. Patterning is performed with 11 orientation regulating force. In addition, the liquid crystal material which forms the retardation layer 8 for 1/4 wavelength plates can use the same liquid crystal material as the retardation layer 9 for 1/2 wavelength plates, for example, following chemical formula (1)-( The compounds represented by 13) are used.

Further, the quarter-wave retardation plate 6 has a half-wave plate shaping resin layer 12 and a half-wave plate retardation layer 9 on the quarter-wave plate retardation layer 8. 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 a fine irregular shape on the surface, that is, a half-wave plate alignment film shape 13 by the shaping treatment.
The half-wave plate retardation layer 9 is formed of a rod-like liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy, and the orientation of the liquid crystal material is the shape of an alignment film for a half-wave plate. Patterning is performed with 13 orientation regulating force. The liquid crystal material forming the half-wave plate retardation layer 9 can be the same liquid crystal material as the quarter-wave plate retardation layer 8 described above. For example, the following chemical formula (1) The compounds represented by (13) are used.
Add 4% of BASF's Irgacure 184 or Irgacure 907 as an initiator to the liquid crystal compounds below, and further add a fluoropolymer, a DIC's MegaFac series, for the purpose of improving coatability. Add about 0.1% to 0.5% depending on the thickness, and use MIBK, cyclohexanone, or a mixed solvent of MIBK and cyclohexanone to dissolve to a solid content concentration of 25% to prepare a coating solution. The substrate is coated with a Miya bar to obtain a drying process for 3 minutes at a setting of 110 ° C., and is oriented and fixed by ultraviolet curing in a nitrogen atmosphere.

  The fine concavo-convex shape according to the alignment film shape 11 for ½ wavelength plate and the alignment film shape 13 for ¼ wavelength plate is formed by a line-shaped (line) uneven shape extending in one direction. Are formed so that the directions extending in the direction of θ1 degrees and θ2 degrees clockwise or counterclockwise with respect to the absorption axis S or the transmission axis of the linearly polarizing plate 5, respectively.

  The quarter-wave retardation layer 106 is not limited to the above-described configuration. For example, the quarter-wave plate shaping resin layer 10 and the half-wave plate shaping resin layer 12 are omitted, and the positive C A quarter-wave plate retardation layer 8 and a half-wave plate retardation layer 9 may be provided on the plate 17. In this case, the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 are formed of a COP (cycloolefin polymer) film or the like stretched in a uniaxial direction or obliquely stretched in a desired direction. The slow axis is arranged to make an angle of θ1 degree and θ2 degree counterclockwise with respect to the absorption axis S or the transmission axis of the linearly polarizing plate 5, respectively. Also, any one of the retardation layers can be composed of a shaping resin layer and an alignment film, and the other can be composed of the COP film or the like.

  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 is supplied from a supply reel 21. In the manufacturing process 20, a liquid crystal material is applied onto the base material 14 by the die 50, and the liquid crystal material is cured by irradiation of ultraviolet rays by the ultraviolet irradiation device 51, thereby creating a configuration related to the positive C plate 17. Next, in the manufacturing process 20, the coating solution of the ultraviolet curable resin 10 is applied onto the positive C plate of 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 according to the alignment film shape 11 for the quarter wavelength plate of the quarter wavelength retardation plate 6 is formed on the peripheral side surface. is there. 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 applied by irradiating the ultraviolet rays 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 a base material. Thereafter, the base material 14 is peeled off from the roll plate 30 together with the ultraviolet curable resin 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 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 wavelength plate retardation layer 8 of the base material 14 by the die 32. To do. In this manufacturing process 20, the roll plate 40 is a cylindrical shaping mold in which the concavo-convex shape according to the alignment film shape 13 for the half-wave plate of the quarter-wave retardation plate 6 is formed on the peripheral side surface. is there. In the manufacturing process 20, the substrate coated with the ultraviolet curable resin 12 is pressed against the peripheral side surface of the roll plate 40 by the pressure roller 34, and the ultraviolet curable resin is obtained 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 is peeled off from the roll plate 40 integrally with the ultraviolet curable resin 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.

[Roll plate manufacturing process]
The manufacturing process of the roll plate which forms the alignment film shape of the shaping resin layer will be described. In addition, although the manufacturing method of the roll plate 30 is demonstrated here, about the roll plate 40, except for the point from which the direction of the rubbing process mentioned later differs, it is the same description as this roll plate 30, and overlapped description. Is omitted. Here, in this manufacturing process, after the peripheral side surface of the base material is smoothed by cutting, an underlayer is produced. Here, the base material is a cylindrical metal material corresponding to the outer shape of the roll plate. The base material is preferably a metal material from the viewpoint of ease of processing and dimensional stability, and more preferably nickel, chromium, stainless steel, copper and the like. In this embodiment, copper is applied as the base material.

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

Subsequently, in this step, an inorganic material layer is formed on the surface of the base layer. In this embodiment, a nickel layer is applied to the inorganic material layer, and the inorganic material layer is formed to a thickness of 100 nm by sputtering. Although various inorganic materials such as metal materials, inorganic oxides, inorganic nitrides, and inorganic carbides can be widely applied to the inorganic material layer, chromium, titanium, nickel, tungsten, stainless metal material, can be applied _{aluminum, SiO 2, SiOx, Al 2} O 3, Cr 2 O 3, TiO 2, Si 3 N 4, AlN, TiN, SiOxNy, SiC, WC, DLC or the like.

  Subsequently, in this step, minute line-shaped uneven shapes are formed on the entire surface of the inorganic material layer by rubbing. Here, this minute line-like uneven shape corresponds to the direction of the slow axis of the retardation layer 8 for quarter-wave plates (in the roll plate 40, the retardation layer 9 for half-wave plates) described above with reference to FIG. It is produced so that it may become the direction to do. As a result, the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 are transferred to the surface shape of the inorganic material layer 72 by the shaping process, and the corresponding alignment film shapes 11, 13 respectively. And the liquid crystal material is aligned by the alignment regulating force of the alignment film shapes 11 and 13.

In this embodiment, a rubbing roll R is constituted by a roll around which a rayon cloth is wound, and the rubbing roll R is rotated at a rotational speed of 100 rpm at a moving speed of 0.1 m / min with a pushing amount of 0.5 mm. The rubbing process was executed by moving in the direction.
By pressing the base material coated with the ultraviolet curable resin to the roll plate 30 produced by the above steps, the shape of the alignment film for 1/4 wavelength plate on the 1/4 wavelength plate shaping resin layer 10 is obtained. 11 will be formed. Similarly, by pressing a base material coated with an ultraviolet curable resin to the roll plate 40 prepared by the above process, the alignment for half-wave plate on the half-wave plate shaping resin layer 12 is performed. A film shape 13 is formed.

As described above, the optical film 3 of the present embodiment satisfies the relational expressions 1) to 3) above, so that the positive C plate 17, the quarter-wave plate phase difference layer 8, 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.
Further, the optical film 3 further satisfies the relational expressions 4) and 5), and is formed of the same liquid crystal material with the quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9. By forming the optical film 3, the optical film 3 having the above-described 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. Accordingly, the substrate to be transferred is the linearly polarizing plate 5, and the layer (transfer layer) used for transfer is the positive C plate 17, the quarter-wave plate retardation layer 8, and the quarter-wave plate shaping resin layer. 10 is a laminate of a retardation layer 9 for a half-wave plate and a shaping resin layer 12 for a half-wave plate.

  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 separator film 223 in sequence, the half-wave plate shaping resin layer 12 according to the quarter-wave retardation plate 206, the half-wave plate retardation layer 9, and the quarter wavelength. A plate-forming resin layer 10, a quarter-wave plate retardation layer 8, and a positive C plate 17 are provided.

  Here, the separator film 223 is a substrate that is detachably supported on a layer to be transferred (transfer layer), and is appropriately peeled and removed when the transfer layer is bonded and laminated on the transfer target substrate. is there. 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 separator film 223 may have a sheet shape as a whole. Alternatively, the separator film 223 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 separator film 223 is 20-100 micrometers. In the case where the peelability from the transfer layer is insufficient, the separator film 223 is provided with a release layer that promotes peeling on the transfer layer side.

  For the release layer, a material having relatively high adhesiveness to the separator film 223 (low peelability) and low adhesiveness to the transfer layer (high peelability) can be applied. In this embodiment, since the uppermost layer of the transfer layer is the half-wave plate shaping resin layer 12 made of an ultraviolet curable resin, for example, a silicon resin (organosilicon polymer) is used for the separator film 223 described above. Compound), fluorine-based resin, melamine resin, epoxy resin, or a mixture of these resins and other appropriate resins (acrylic resin, cellulose-based resin, polyester resin, etc.). In this embodiment, a release layer made of melamine resin is provided on the separator film 223 made of the above-described PET film, and wettability with respect to the coating solution of the ultraviolet curable resin provided on the release layer is ensured.

  Instead of providing a release layer made of melamine resin or the like 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 separator film and the release layer may be omitted. Alternatively, a release layer may be omitted by applying a TAC film without a so-called permeation layer called a nonsol to the separator film. In this way, the configuration can be simplified.

  Incidentally, when the release property by the release layer is insufficient, a release layer may be provided between the separator film 223 and the release layer, and the release property by the release layer may be supplemented by this 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 0.1 to 10 μm. The release layer may be provided on the separator film 223 or may be provided on the release layer.

The half-wave plate shaping resin layer 12 is formed by applying an ultraviolet curable resin coating solution on the separator film 223 or on a release layer formed on the separator film 223. The The half-wave plate shaping resin layer 12 is formed by using a shaping mold (roll plate) in which the alignment film shape 13 for the half-wave plate is formed with fine irregularities on the peripheral side surface for shaping. It is created by molding process. The retardation layer 9 for half-wave plates is formed by applying a liquid crystal material on the alignment film shape 13 for half-wave plates and curing it.
The quarter-wave plate shaping resin layer 10 is formed by applying an ultraviolet curable resin coating solution on the half-wave plate retardation layer 9. Further, the quarter-wave plate orientation film shape 11 is shaped into the quarter-wave plate shaping resin layer 10 by using a shaping mold in the same manner as the half-wave plate orientation film shape 13. Created by processing. The quarter-wave plate retardation layer 8 is formed by applying and curing a liquid crystal material on the quarter-wave plate alignment film shape 11.
The positive C plate 17 is formed by applying a coating liquid of a rod-like liquid crystal compound on the quarter-wave plate retardation layer 8. Thus, in the transfer body, the half-wave plate shaping resin layer 12, the half-wave plate retardation layer 9, and the quarter-wave plate use, which have the layer configuration related to these quarter-wave retardation plates. The shaping resin layer 10, the quarter-wave plate retardation layer 8, and the positive C plate 17 are transfer layers used for transfer.

Further, the transfer film 220 is provided with the adhesive layer 4 and the support base material 221 on the transfer layer according to the layer configuration related to the quarter-wave retardation plate 206.
The support base material 221 is a release sheet that covers the surface of the pressure-sensitive adhesive layer 4 so as to be releasable. After the transfer layer is adhered and laminated on the transfer target substrate, the support base material 221 is appropriately peeled off and removed appropriately. Sheet. The support base material 221 is provided to prevent the adhesive layer 4 from being exposed and causing unnecessary adhesion to unnecessary articles, and is peeled off and removed immediately before transfer.

In the optical film 203, the optical functional layer 16 of the linearly polarizing plate 5 is bonded to the half-wave plate shaping resin layer 12 which is exposed when the separator film 223 of the transfer film 220 is peeled off by the adhesive layer 207. It is formed by doing.
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 adhesive layer 207 may be provided on the optical functional layer 16 of the linearly polarizing plate 5 or may be provided on the half-wave plate shaping resin layer 12.

  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, the color data in the range of the polar angle of 60 ° is a sensory evaluation by visual observation of the measurer measured from an oblique direction (polar angle of 60 °) of the display screen. Here, the range of the polar angle of 60 ° refers to a range inclined by 60 degrees from the normal line of the surface of the optical film. Further, the first layer, the second layer, and the third layer in FIG. 6 are laminated in the order of the third layer, the second layer, and the first layer from the display screen side of the image display panel 2, respectively.
The in-plane retardation (R (550)) and the retardation in the thickness direction (Rth (550)) of each retardation layer were measured using KOBRA-WR manufactured by Oji Scientific Instruments. In the evaluation, an organic EL panel of a mobile phone (Samsung, Galaxy SIII) was used as an image display panel used for each image display device. In addition, the above-described color evaluation was performed in a state where no image was displayed on the display screen of the image display panel.

The optical film 3 of the image display device 1 of Example 1 includes, from the image display panel 2 side, a positive C plate 17, a quarter-wave plate shaping resin layer 10, a quarter-wave plate retardation layer 8, 1. The two-wavelength plate shaping resin layer 12, the half-wavelength plate retardation layer 9, and the linear polarizing plate 5 are laminated in this order.
The retardation layer 9 for a half-wave plate has an in-plane retardation with respect to transmitted light having a wavelength of 550 nm, with the inclination of the slow axis with respect to the absorption axis or transmission axis of the transmitted light of the linear polarizing plate 5 being θ1 = 10 °. R1 (550) = 266 nm. The quarter-wave plate retardation layer 8 has an in-plane with respect to transmitted light having a wavelength of 550 nm and an inclination of the slow axis with respect to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate 5. The retardation of R2 (550) = 132 nm. Further, the positive C plate 17 has a retardation in the thickness direction of Rth3 (550) = − 135 nm.

The optical film 3 of the image display device 1 of Example 2 has the same layer configuration as the optical film of Example 1 described above.
The half-wave plate retardation layer 9 has θ1 = 7.5 ° and R1 (550) = 276 nm. The quarter-wave plate retardation layer 8 has θ2 = 60 ° and R2 (550) = 138 nm. Further, the positive C plate 17 has Rth3 (550) = − 135 nm.

The optical film 3 of the image display device 1 of Example 3 has the same layer configuration as the optical film of Example 1 described above.
The half-wave plate retardation layer 9 has θ1 = 15 ° and R1 (550) = 260 nm. The quarter-wave plate retardation layer 8 has θ2 = 73 ° and R2 (550) = 133 nm. Further, the positive C plate 17 has Rth3 (550) = − 135 nm.

The optical film 3 of the image display device 1 of Example 4 has the same layer configuration as the optical film of Example 1 described above.
The half-wave plate retardation layer 9 has θ1 = 15 ° and R1 (550) = 260 nm. The quarter-wave plate retardation layer 8 has θ2 = 73 ° and R2 (550) = 133 nm. Further, the positive C plate 17 has Rth3 (550) = − 130 nm.

The optical film 3 of the image display device 1 of Example 5 includes, from the image display panel 2 side, a positive C plate 17, a quarter-wave plate retardation layer 8, a half-wave plate retardation layer 9, and linearly polarized light. The plates 5 are stacked in this order. Here, the quarter-wave plate retardation layer 8 and the half-wave plate retardation layer 9 are composed of COP films.
The half-wave plate retardation layer 9 has θ1 = 15 ° and R1 (550) = 275 nm. Further, the quarter-wave plate retardation layer 8 has θ2 = 75 ° and R2 (550) = 140 nm. Further, the positive C plate 17 has Rth3 (550) = − 130 nm.

The optical film 3 of the image display device 1 of Example 6 has the same layer configuration as the optical film of Example 1 described above.
The half-wave plate retardation layer 9 has θ1 = 15 ° and R1 (550) = 240 nm. Further, the quarter-wave plate retardation layer 8 has θ2 = 73 ° and R2 (550) = 120 nm. Further, the positive C plate 17 has Rth3 (550) = − 135 nm.

The optical film 3 of the image display device 1 of Example 7 has the same layer configuration as the optical film of Example 1 described above.
The half-wave plate retardation layer 9 has θ1 = 15 ° and R1 (550) = 240 nm. Further, the quarter-wave plate retardation layer 8 has θ2 = 73 ° and R2 (550) = 120 nm. Further, the positive C plate 17 has Rth3 (550) = − 100 nm.

The optical film 3 of the image display device 1 of Example 8 has the same layer configuration as the optical film of Example 1 described above.
The half-wave plate retardation layer 9 has θ1 = 15 ° and R1 (550) = 240 nm. Further, the quarter-wave plate retardation layer 8 has θ2 = 73 ° and R2 (550) = 120 nm. Further, the positive C plate 17 has Rth3 (550) = − 80 nm.

The optical film 3 of the image display device 1 of Example 9 includes, from the image display panel 2 side, a positive C plate 17, a quarter-wave plate retardation layer 8, a half-wave plate shaping resin layer 12, 1. / The retardation layer 9 for two-wave plates and the linear polarizing plate 5 are laminated in this order. Here, the quarter-wave plate retardation layer 8 is composed of a COP film.
The half-wave plate retardation layer 9 has θ1 = 10 ° and R1 (550) = 265 nm. The quarter-wave plate retardation layer 8 has θ2 = 65 ° and R2 (550) = 133 nm. Further, the positive C plate 17 has Rth3 (550) = − 60 nm.

On the other hand, the optical film of the image display device of Comparative Example 1 is laminated from the image display panel side in the order of a quarter-wave plate retardation layer, a half-wave plate retardation layer, and a linear polarizing plate. The positive C plate is not provided.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 260 nm. The quarter-wave plate retardation layer has θ2 = 73 ° and R2 (550) = 133 nm.

The optical film of the image display device of Comparative Example 2 is formed by laminating a quarter-wave plate retardation layer, a half-wave plate retardation layer, and a linear polarizing plate in this order from the image display panel side. . Here, the quarter-wave plate retardation layer and the half-wave plate retardation layer are composed of COP films.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 275 nm. Further, the quarter-wave plate retardation layer 8 has θ2 = 75 ° and R2 (550) = 140 nm.

From the image display panel side, the optical film of the image display device of Comparative Example 3 has a positive C plate, a quarter-wave plate shaping resin layer, a quarter-wave plate retardation layer, and a half-wave plate coating. It is laminated in the order of a mold resin layer, a half-wave plate retardation layer, and a linearly polarizing plate.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 260 nm. The quarter-wave plate retardation layer has θ2 = 73 ° and R2 (550) = 133 nm. Further, the positive C plate 17 has Rth3 (550) = − 200 nm.

The optical film of the image display device of Comparative Example 4 has the same layer configuration as the optical film of Comparative Example 3 described above.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 260 nm. The quarter-wave plate retardation layer has θ2 = 73 ° and R2 (550) = 133 nm. Further, the positive C plate 17 has Rth3 (550) = − 150 nm.

The optical film of the image display device of Comparative Example 5 has the same layer configuration as the optical film of Comparative Example 3 described above.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 260 nm. The quarter-wave plate retardation layer has θ2 = 73 ° and R2 (550) = 133 nm. Further, the positive C plate 17 has Rth3 (550) = − 30 nm.

The optical film of the image display device of Comparative Example 6 is, from the image display panel side, a quarter-wave plate shaping resin layer, a quarter-wave plate retardation layer, a half-wave plate shaping resin layer, A retardation layer for a half-wave plate, a positive C plate, and a linear polarizing plate are laminated in this order.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 240 nm. The quarter-wave plate retardation layer has θ2 = 73 ° and R2 (550) = 120 nm. Further, the positive C plate 17 has Rth3 (550) = − 100 nm.

From the image display panel side, the optical film of the image display device of Comparative Example 7 has a quarter-wave plate shaping resin layer, a quarter-wave plate retardation layer, a positive C plate, and a half-wave plate coating. It is laminated in the order of a mold resin layer, a half-wave plate retardation layer, and a linearly polarizing plate.
The retardation layer for a half-wave plate has θ1 = 15 ° and R1 (550) = 240 nm. The quarter-wave plate retardation layer has θ2 = 73 ° and R2 (550) = 120 nm. Further, the positive C plate 17 has Rth3 (550) = − 100 nm.

  As shown in FIG. 6, in the image display device according to Comparative Example 1, the color of the display screen observed from an oblique direction with respect to the normal line of the display screen was greenish. In the image display device according to Comparative Example 2, the color of the display screen was greenish. Furthermore, in the image display device according to Comparative Example 3, the color of the display screen was bluish-purple. In the image display device according to Comparative Example 4, the color of the display screen was slightly bluish-purple. In the image display device according to Comparative Example 5, the color of the display screen was slightly greenish. In the image display device according to Comparative Example 6, the color of the display screen was improved to black, but there was no change in the viewing angle contrast. In the image display device according to Comparative Example 7, the color of the display screen was improved to black, but there was no change in the viewing angle contrast.

In contrast, in the image display devices 1 according to the respective examples (1 to 9), the color of the display screen was black or almost black. Therefore, it was confirmed that 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, the optical film according to each example has the above relational expressions 1) to 3),
1) −140 nm ≦ Rth3 ≦ −40 nm
2) 7 ° <| θ1 | <17 °
3) 59 ° <| θ2 | <76 °
It was also confirmed that all of these were satisfied. Moreover, it was confirmed that the optical film which concerns on each Example also satisfy | fills the above-mentioned relational expressions 6) and 7).
Therefore, it can be confirmed from the evaluation result that the appearance of the display screen observed from an oblique direction with respect to the normal line of the display screen of the image display device 1 can be improved by satisfying all the relational expressions 1) to 3). it can.

  Moreover, the optical film of Example 4 and Comparative Example 1 and the optical film of Example 5 and Comparative Example 2 are different only by whether or not each has a positive C plate, as shown in FIG. . Comparing each example and each comparative example, it is confirmed that the optical film of the example provided with the positive C plate can emphasize the blackness of the display screen of the image display device more than the optical film of the comparative example. It was done.

Further, even if the positive C plate is provided with the same configuration as each example as in the image display devices of Comparative Examples 3 to 5, the retardation Rth in the thickness direction of the positive C plate satisfies the above relational expression 1). When not satisfying, it was also confirmed that the color of the display screen of the image display device cannot be made black, and the blackness cannot be sufficiently emphasized.
Further, as in Comparative Example 6 and Comparative Example 7, even when the stacking position of the positive C plate is arranged at a position different from the stacking position of the example, the color of the display screen of the image display device is black. It was also confirmed that the blackness cannot be sufficiently emphasized.

The optical films of Example 3, Example 4, and Examples 6 to 8 satisfy not only the above relational expressions 1) to 3) but also the relational expressions 4) and 5). Accordingly, it is also confirmed that the blackness of the display screen of the image display device can be more effectively emphasized by satisfying not only the above-described relational expressions 1) to 3) but also the relational expressions 4) and 5). It was done.
Further, as in the optical films of Example 1, Example 2, Example 5, and Example 9, the above relational expressions 1) to 3) are satisfied, but the relational expressions 4) and 5) are not satisfied. However, it has also been confirmed that the display screen of the image display device can enhance the blackness sufficiently.

[Evaluation of optical film]
Next, evaluation results of the chromaticity and luminance of the optical film in another example will be described.
In order to evaluate the color and contrast from an oblique direction, reflection chromaticity and reflection luminance were measured with EZ Contrast manufactured by ELDIM. Each data was calculated by averaging data of reflection chromaticity and reflection luminance measured from all directions at a polar angle of 60 °.
FIG. 7 is a diagram showing the evaluation results of the chromaticity of the optical film of the example according to the present invention and the optical film of the comparative example. FIG. 7A is a diagram showing an average value of chromaticity of the example and the comparative example, and FIG. 7B is a diagram showing standard deviation (3σ) of chromaticity of the example and the comparative example. .
FIG. 8 is a diagram showing the evaluation results of the reflection luminance of the optical film of the example according to the present invention and the optical film of the comparative example. FIG. 8A is a diagram showing the average value of the reflection luminance of the example and the comparative example, and FIG. 8B is a diagram showing the standard deviation (3σ) of the reflection luminance of the example and the comparative example. .

The optical film 3 of Example 11 shown in FIGS. 7 and 8 includes a positive C plate 17, a quarter-wave plate shaping resin layer 10, a quarter-wave plate retardation layer 8, and a half-wave plate. The shaping resin layer 12, the half-wave plate retardation layer 9, and the linear polarizing plate 5 are sequentially laminated.
The retardation layer 9 for a half-wave plate has an in-plane retardation for transmitted light having a wavelength of 550 nm and an inclination of the slow axis with respect to the absorption axis or transmission axis of the transmitted light of the linear polarizing plate 5. 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 or transmission axis of the transmitted light of the linearly polarizing plate 5 is θ2 = 75 °, and is in-plane with respect to the transmitted light having a wavelength of 550 nm. The retardation of R2 (550) = 120 nm. Further, the positive C plate 17 has a retardation in the thickness direction of Rth (550) = − 80 nm.

  The optical film 3 of Example 12 has a layer configuration equivalent to that of the optical film of Example 11. Also, the slow axis inclinations (θ1, θ2) of the retardation layer 9 for half-wave plates and the retardation layer 8 for quarter-wave plates in Example 12 and in-plane retardation (R1 (550), The value of R2 (550)) is equivalent to that of the optical film of Example 11. The positive C plate 17 of Example 12 has a retardation in the thickness direction of Rth (550) = − 100 nm.

  The optical film 3 of Example 13 has a layer configuration equivalent to that of the optical film of Example 11. Also, the slow axis inclinations (θ1, θ2) of the half-wave plate retardation layer 9 and the quarter-wave plate retardation layer 8 of Example 13 and in-plane retardation (R1 (550), The value of R2 (550)) is equivalent to that of the optical film of Example 11. The positive C plate 17 of Example 13 has a retardation in the thickness direction of Rth (550) = − 120 nm.

On the other hand, the optical film of Comparative Example 11 has a configuration in which the positive C plate is omitted from the optical film of Example 11, that is, the quarter-wave plate shaping resin layer 10 and the quarter-wave plate. A retardation layer 8, a half-wave plate shaping resin layer 12, a half-wave plate retardation layer 9, and a linear polarizing plate 5 are sequentially laminated.
In addition, the slow axis inclinations (θ1, θ2) of the retardation layer 9 for half-wave plates and the retardation layer 8 for quarter-wave plates in Comparative Example 11 and in-plane retardation (R1 (550), The value of R2 (550)) is equivalent to that of the optical film of Example 11.

  When comparing the above-described Examples and Comparative Examples, the coordinates of the average value of chromaticity at a polar angle of 60 degrees are as shown in FIG. In comparison, the chromaticity coordinates tended to be smaller for both the x and y coordinates. That is, the optical films of Examples 11 to 13 indicate that the color shifts from the yellowish green side to the blue side as compared with the optical film of Comparative Example 11, and are displayed when arranged on the image display panel. The blackness of the screen can be emphasized more than in the comparative example. In the chromaticity diagram, the coordinates of x = 0.33 and y = 0.33 indicate an achromatic color (white).

  Further, the standard deviation (3σ) of chromaticity at a polar angle of 60 degrees is, as shown in FIG. 7B, the average value (3σave in FIG. 7B) of the optical film of each example is a comparative example. It was confirmed that the variation in chromaticity was smaller and the chromaticity variation was smaller.

As shown in FIG. 8A, the reflection luminance with respect to incident light at a polar angle of 60 degrees can be suppressed lower than that of the comparative example in the optical film 3 of Example 11, that is, the antireflection function is improved. It was confirmed that
In addition, as shown in FIG. 8B, the optical film of Example 11 also has a standard deviation (3σ) of the reflected luminance that is lower than that of the comparative example, confirming that the variation in reflected luminance is reduced. It was done.

As described above, as described above, the optical film of each example can emphasize the blackness of the display screen when applied to the display screen panel as compared with the case of the comparative example 11, and can be compared with the comparative example. Thus, variation in chromaticity can be reduced. The optical films of these examples also satisfy the above-described relational expressions 1) to 3), and when arranged in the image display device 1, improve the appearance of the display screen observed from the oblique direction of the display screen. It was confirmed that
Further, from the results shown in FIG. 7B, it was confirmed that the variation in chromaticity can be more effectively reduced when the retardation Rth in the thickness direction of the positive C plate 17 is −100 nm to −90 nm. . Furthermore, from the results shown in FIG. 8, it was confirmed that when the retardation Rth in the thickness direction of the positive C plate 17 is −80 nm, the average value and standard deviation of the reflected luminance can be reduced.
Accordingly, the optical film 3 enhances the blackness of the display screen and prevents reflection when it is placed in the image display device 1 by appropriately setting the retardation of the positive C plate 17 according to the use application. Function can be improved. Thereby, the external appearance of the display screen observed from the oblique direction of the display screen can be improved more effectively.

[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 in sequence, the positive C plate 17, the quarter-wave plate shaping resin layer 10, and the quarter-wave plate. Although the example which comprises the phase difference layer 8, the half-wave plate shaping resin layer 12, and the half-wave plate phase difference layer 9 was shown, it is not limited to this.
For example, on the lower surface of the substrate, the half-wave plate shaping resin layer 12, the half-wave plate retardation layer 9, the quarter-wave plate shaping resin layer 10, the quarter-wave plate position The phase difference layer 8 and the positive C plate 17 may be formed. In this case, the quarter-wave retardation plate needs to be provided with the adhesive layer 7 on the upper surface of the substrate and the adhesive layer 4 on the lower surface of the positive C plate 17.
Further, a half-wave plate shaping resin layer 12 and a half-wave plate retardation layer 9 are sequentially formed on the upper surface of the base material, and sequentially for the quarter-wave plate on the lower surface of the base material. The shaping resin layer 10, the quarter-wave plate retardation layer 8, and the positive C plate 17 may be formed.

(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, it is necessary to form a transfer body in which the half-wave plate retardation layer 9, the quarter-wave plate retardation layer 8, and the positive C plate 17 are laminated in this order on the support substrate.

(3) In each embodiment, the case where the alignment film shape is created by the shaping process has been described. However, the present invention is not limited to this, and the present invention can be applied to the case where the alignment film shape is created by a photo-alignment technique. it can. In addition, for example, by applying a photo-alignment liquid crystal polymer to the retardation layer, such an alignment film shape is omitted, and the retardation layer is prepared by directly aligning the liquid crystal material by irradiation with ultraviolet rays or the like by linearly polarized light. It can also be widely applied to.

(4) In each embodiment, although the positive C plate 17 showed the example comprised by liquid crystal material, it is not limited to this, For example, from film-like base materials, such as an acrylic material and a TAC material, It may be configured. In this case, it is not necessary to provide the positive C plate on the base material, and the optical film can be made thinner than in the case of the first embodiment described above.

(5) 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.

(6) In each embodiment, the case where the shaping process is performed by the roll plate has been described. However, the present invention is not limited thereto, and can be widely applied to the case where the shaping process is performed by the lithographic plate.

(7) In the second embodiment, the transfer film 220 is formed by laminating the positive C plate 17, the quarter-wave plate retardation layer 8, and the half-wave plate retardation layer 9 on the support base material. An example is shown, but the present invention is not limited to this. For example, the positive C plate 17, the quarter-wave plate retardation layer 8, and the half-wave plate retardation layer 9 are respectively formed on individual support base materials, and a transfer film is formed for each layer. Thus, the optical film may be formed through an adhesive material or the like.

(8) The optical film 3 has the retardations θ1 and θ2 of the slow axis of the retardation layer 9 for half-wave plates and the retardation layer 8 for quarter-wave plates satisfy the above relational expressions 2) and 3). It is not limited to satisfying. For example, in the optical film 3 composed of a retardation layer for a half-wave plate composed of a COP film or the like, a retardation layer for a quarter-wave plate composed of a liquid crystal material, and a positive C plate, Even when θ1 = 22.5 ° and θ2 = 90 °, the appearance of the display screen observed from an oblique direction of the display screen can be improved by providing the positive C plate that satisfies the above relational expression 1).

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 shape 12 1/2 wavelength plate shaping resin layer 13 1/2 wavelength plate alignment film shape 14, 15 Base material 16 Optical functional layer 17 Positive C plate 220 Transfer film 221 Support substrate 223 Separator film 20 Manufacturing process 21 Supply reels 22, 29, 32, 39, 50 Dies 24, 34 Pressure rollers 25, 27, 35, 37, 51 UV Irradiation device 26, 36 Peeling roller 30, 40 Roll plate 31 Conveying roller

Claims (13)

An optical functional layer of a linearly polarizing plate that functions as a linearly polarizing plate;
A retardation layer for a half-wave plate that imparts a phase difference of half a wavelength to transmitted light;
A quarter-wave plate retardation layer for imparting a quarter-wave phase difference to transmitted light;
A positive C plate having an in-plane refractive index smaller than the refractive index in the thickness direction is sequentially laminated,
The positive C plate has a retardation Rth in the thickness direction,
Satisfies −140 nm ≦ Rth ≦ −40 nm,
The half-wave plate retardation layer and the quarter-wave plate retardation layer are
The inclination of the slow axis of the retardation layer for the half-wave plate with respect to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate is defined as θ1, and the 1 with respect to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate. / 4 When the inclination of the slow axis of the retardation layer for a wavelength plate is θ2,
7 ° <| θ1 | <17 °,
59 ° <| θ2 | <76 °
Satisfy the relationship
R1 represents the retardation in the plane of the retardation layer for a half-wave plate with respect to transmitted light having a wavelength of 550 nm, and R2 represents the retardation in the surface of the retardation layer for a quarter-wave plate with respect to transmitted light having a wavelength of 550 nm. When
2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °,
2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550)
An optical film characterized by satisfying this relationship. The quarter-wave plate retardation layer and the half-wave plate retardation layer have respective in-plane retardations (R1 (550), R2 (550)),
230 nm ≦ R1 (550) ≦ 276 nm,
110 nm ≦ R2 (550) ≦ 150 nm
The optical film according to claim 1, wherein the following relational expression is satisfied. The standard deviation (3σ) and the Y coordinate value standard deviation (3σ) of the x-coordinate value of the reflected chromaticity measured from all directions at a polar angle of 60 ° are 0.0299 or less,
The average value of the x coordinate of the reflection chromaticity is 0.3049 or more and 0.3186 or less,
An average value of the y-coordinates of the reflection chromaticity is not less than 0.3493 and not more than 0.3531;
The optical film according to claim 1 or 2. The quarter-wave plate retardation layer and the half-wave plate retardation layer are formed of the same liquid crystal material;
The optical film according to any one of claims 1 to 3, wherein: The positive C plate is formed of a liquid crystal compound;
The optical film of any one of Claim 1 to 4 characterized by these. It has an image display panel,
Disposing the optical film according to any one of claims 1 to 5 on the image display panel;
An image display device characterized by the above. 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 half-wave plate retardation layer that imparts a phase difference of ½ wavelength to transmitted light, and a quarter-wave plate retardation layer that imparts a phase difference of ¼ wavelength to transmitted light, A transfer layer in which a positive C plate having an in-plane refractive index smaller than the refractive index in the thickness direction is sequentially laminated;
A support for holding the transfer layer,
The positive C plate has a retardation Rth in the thickness direction,
Satisfies −140 nm ≦ Rth ≦ −40 nm,
The half-wave plate retardation layer and the quarter-wave plate retardation layer are
The inclination of the slow axis of the retardation layer for the half-wave plate with respect to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate is defined as θ1, and the 1 with respect to the absorption axis or transmission axis of the transmitted light of the linearly polarizing plate. / 4 When the inclination of the slow axis of the retardation layer for a wavelength plate is θ2,
7 ° <| θ1 | <17 °,
59 ° <| θ2 | <76 °
Satisfy the relationship
R1 represents the retardation in the plane of the retardation layer for a half-wave plate with respect to transmitted light having a wavelength of 550 nm, and R2 represents the retardation in the surface of the retardation layer for a quarter-wave plate with respect to transmitted light having a wavelength of 550 nm. When
2 | θ1 | + 35 ° <| θ2 | <2 | θ1 | + 45 °,
2 (R2 (550) -20) <R1 (550) ≦ 2R2 (550)
An optical film transfer body characterized by satisfying the above relationship. The quarter-wave plate retardation layer and the half-wave plate retardation layer have respective in-plane retardations (R1 (550), R2 (550)),
230 nm ≦ R1 (550) ≦ 276 nm,
110 nm ≦ R2 (550) ≦ 150 nm
The optical film transfer body according to claim 7, wherein the following relational expression is satisfied. The standard deviation (3σ) and the Y coordinate value standard deviation (3σ) of the x-coordinate value of the reflected chromaticity measured from all directions at a polar angle of 60 ° are 0.0299 or less,
The average value of the x coordinate of the reflection chromaticity is 0.3049 or more and 0.3186 or less,
An average value of the y-coordinates of the reflection chromaticity is not less than 0.3493 and not more than 0.3531;
The transfer body for optical films according to claim 7 or 8. The positive C plate is formed of a liquid crystal compound;
The transfer body for optical films according to any one of claims 7 to 9, wherein: The support is a separator film;
The transfer layer comprises an adhesive layer covered by the support;
The optical film transfer body according to any one of claims 7 to 10, 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 ¼ wavelength phase difference plate is an optical functional layer by the transfer layer provided on the optical film transfer body according to any one of claims 6 to 10,
An optical film characterized by It has an image display panel,
The optical film according to claim 12 is disposed on the image display panel,
An image display device characterized by the above.

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