Phase difference film, laminate optical film, optical article, and virtual-reality display device

Abstract

The present invention addresses the problem of providing a phase difference film that causes minimal ghosting when used in a virtual-reality display device, an electronic viewfinder, or the like, and a laminate optical film, an optical article, and a virtual-reality display device. In this phase difference film, an optical interference layer and a phase difference layer are arranged adjacent to each other in the stated order, and the film thickness of the optical interference layer satisfies a range of 60-110 nm or 230-330 nm.

Description

Retardation film, laminated optical film, optical article, virtual reality display device

[0001] The present invention relates to a retardation film, a laminated optical film, an optical article, and a virtual reality display device.

[0002] A reflective polarizer is a polarizer that reflects one polarized light and transmits the other polarized light. The reflected light and transmitted light by a reflective polarizer are polarized in mutually orthogonal directions. Here, the orthogonal polarization states refer to polarization states located at antipodes on the Poincaré sphere, such as mutually orthogonal linearly polarized light, and right-handed circularly polarized light and left-handed circularly polarized light.

[0003] Known linear reflective polarizers that produce linearly polarized transmitted and reflected light include, for example, a film formed by stretching a dielectric multilayer film as described in Patent Document 1 and a wire grid polarizer as described in Patent Document 2.

[0004] Furthermore, as a reflective circular polarizer in which transmitted light and reflected light become circularly polarized light, for example, a film having a light-reflecting layer in which a cholesteric liquid crystal phase is fixed, as described in Patent Document 3, is known.

[0005] Reflective polarizers are used to extract only specific polarized light from incident light or to split incident light into two polarized lights. For example, in liquid crystal display devices, they are used as brightness enhancement films that reflect and reuse unwanted polarized light from the backlight, thereby improving light utilization efficiency. They are also used as beam splitters in liquid crystal projectors that split light from a light source into two linearly polarized lights and supply each to a liquid crystal panel.

[0006] In recent years, a method has been proposed in which a reflective polarizer is used to reflect a portion of external light and / or light from an image display device to generate a virtual image or a real image. For example, Patent Document 4 discloses an in-vehicle rearview mirror that uses a reflective polarizer to reflect light from behind. Furthermore, Patent Document 5 discloses a method for making a display unit smaller and thinner by arranging a linear reflective polarizer and a half mirror (semi-transmitting mirror) in a condensing lens system of a virtual reality display device (head-mounted display) and further arranging a retardation film having the function of a quarter-wave plate between them.

[0007] Japanese Patent Application Laid-Open No. 2011-053705 Japanese Patent Application Laid-Open No. 2015-028656 Japanese Patent No. 6277088 Japanese Patent Application Laid-Open No. 2017-227720 Japanese Patent Application Laid-Open No. 2003-504663

[0008] According to the investigations of the present inventors, ghost images were observed in the virtual reality display device described in Reference 5, and there was room for further improvement.

[0009] The present invention has been made in view of the above-mentioned problems, and the problem that the present invention aims to solve is to provide a retardation film, a laminated optical film, an optical article, and a virtual reality display device that cause less ghosting when used in a virtual reality display device, an electronic viewfinder, or the like.

[0010] The present inventors have conducted extensive research into the above-mentioned problems and have found that the above-mentioned problems can be achieved by the following configurations. [1] A retardation film comprising a light interference layer and a retardation layer disposed adjacent to each other in this order, wherein the film thickness of the light interference layer is 60 nm to 110 nm or 230 nm to 330 nm. [2] The retardation film according to [1], wherein the refractive index in the in-plane direction of the light interference layer is 1.50 to 1.70. [3] The retardation film according to [1], wherein the refractive index in the in-plane direction of the light interference layer is 1.53 to 1.59. [4] A retardation film further comprising an adhesive layer, wherein the adhesive layer, the light interference layer, and the retardation layer are disposed adjacent to each other in this order, wherein when the refractive index of the adhesive layer is nA and the average refractive index of the retardation layer is nL, the refractive index nI in the in-plane direction of the light interference layer is (nA×nL).１／２ −0.03≦nI≦(nA×nL) １／２ +0.03. [5] The retardation film according to any one of [1] to [3], wherein the optical interference layer is a photo-alignment film. [6] The retardation film according to any one of [1] to [4], wherein the optical interference layer is a C plate. [7] The retardation film according to [6], wherein a compound having a cinnamoyl group is present between the C plate and the retardation layer. [8] The retardation film according to any one of [1] to [4], wherein the optical interference layer is a hard coat layer. [9] A laminated optical film having at least a retardation film and a linear reflective polarizer, wherein the retardation film is the retardation film according to any one of [1] to [8], and the linear reflective polarizer is disposed on the opposite side of the retardation layer from the optical interference layer.

[10] The laminated optical film according to [9], further comprising a linear polarizer.

[11] The laminated optical film according to

[10] , wherein the linear polarizer comprises a light-absorbing anisotropic layer containing at least a liquid crystal compound and a dichroic material.

[12] The laminated optical film according to [9], further comprising a positive C-plate.

[13] The laminated optical film according to [9], further comprising an antireflection layer.

[14] The laminated optical film according to

[13] , wherein the antireflection layer is a moth-eye film or an AR film.

[15] The laminated optical film according to [9], comprising a resin substrate having a peak temperature of loss tangent tanδ of 170°C or less.

[16] An optical article comprising the laminated optical film according to any one of [9] to

[15] and a lens.

[17] A virtual reality display device comprising the optical article according to

[16] .

[0011] According to the present invention, it is possible to provide a retardation film, a laminated optical film, an optical article, and a virtual reality display device that cause less ghosting when used in a virtual reality display device, an electronic viewfinder, or the like.

[0012] FIG. 1 is a schematic diagram showing an example of a retardation film of the present invention. FIG. 2 is a schematic diagram showing another example of a retardation film of the present invention. FIG. 3 is an example of a virtual reality display device using the laminated optical film of the present invention. FIG. 4 is an example of a virtual reality display device using the laminated optical film of the present invention. FIG. 5 is a schematic diagram showing an example of the laminated optical film of the present invention. FIG. 6 is a diagram for explaining the action of a conventional retardation film. FIG. 7 is a diagram for explaining the action of the retardation film of the present invention. FIG. 8 is another example of a virtual reality display device using the retardation film of the present invention.

[0013] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0014] In this specification, "orthogonal" does not mean an angle of exactly 90°, but means 90°±10°, preferably 90°±5°. "Parallel" does not mean an angle of exactly 0°, but means 0°±10°, preferably 0°±5°. "45°" does not mean an angle of exactly 45°, but means 45°±10°, preferably 45°±5°.

[0015] In this specification, "absorption axis" refers to the polarization direction in which absorbance is maximized in a plane when linearly polarized light is incident. "Reflection axis" refers to the polarization direction in which reflectance is maximized in a plane when linearly polarized light is incident. "Transmission axis" refers to the direction perpendicular to the absorption axis or reflection axis in a plane. "Slow axis" refers to the direction in which refractive index is maximized in a plane.

[0016] In this specification, unless otherwise specified, phase difference refers to in-plane retardation, and is referred to as Re(λ). Here, Re(λ) represents the in-plane retardation at a wavelength λ, and unless otherwise specified, the wavelength λ is 550 nm. Furthermore, in this specification, the retardation in the thickness direction at a wavelength λ is referred to as Rth(λ), and unless otherwise specified, the wavelength λ is 550 nm. Re(λ) and Rth(λ) can be values ​​measured at a wavelength λ using an AxoScan OPMF-1 (manufactured by OptoScience). By inputting the average refractive index ((nx + ny + nz) / 3) and film thickness (d (μm)) into AxoScan, the following slow axis direction (°) can be calculated: Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d.

[0017] [Retardation Film] The retardation film of the present invention comprises a light interference layer and a retardation layer disposed adjacent to each other in this order, and the thickness of the light interference layer is 60 nm to 110 nm, or 230 nm to 330 nm.

[0018] The retardation film of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a retardation film 10. In the embodiment shown in FIG. 1, the retardation film 10 is composed of a retardation layer 21 and a light interference layer 22, which are arranged adjacent to each other. The retardation film of the present invention can be used in a laminated optical film. The laminated optical film can be used in an optical article used in a virtual reality display device. By configuring the retardation film as described above and setting the film thickness of the light interference layer to satisfy the above relationship, an anti-reflection effect can be imparted. This makes it possible to suppress reflected light caused by interfacial reflection between the retardation layer and a layer adjacent to the retardation layer (e.g., an adhesive layer and a lens) in a conventional configuration without a light interference layer. Here, when circularly polarized light is reflected at an interface, the rotation direction of the circularly polarized light changes (e.g., right-handed circularly polarized light is converted to left-handed circularly polarized light by interfacial reflection). The change in rotation direction of the circularly polarized light reflected at an interface is one of the causes of ghosting. Therefore, it is believed that suppressing interfacial reflection can suppress the occurrence of ghosting. The retardation film of the present invention may include an adhesive layer for bonding the retardation film to a lens. Fig. 2 is a schematic cross-sectional view showing an example of the configuration of the retardation film 11. In the embodiment shown in Fig. 2, the retardation film 11 is composed of a retardation layer 21, an optical interference layer 22, and an adhesive layer 23, which are arranged adjacent to each other.

[0019] The function of the retardation film of the present invention will be described in more detail below.

[0020] First, a conventional configuration without an optical interference layer will be described with reference to FIG.

[0021] 6 is an example in which a retardation film 90 having a retardation layer 21 and an adhesive layer 23 is laminated on a lens 600 on the adhesive layer 23 side, and a linear reflective polarizer 102 is laminated on the retardation layer 21 side via an adhesive layer 101. Such a configuration corresponds to an optical article used in a virtual reality display device described later, and is used as a reciprocating optical system (folding optical system) in combination with a half mirror. When used as a reciprocating optical system, the upper side (lens 600 side) in FIG. 6 is the image display device side, and the lower side (linear reflective polarizer 102 side) is the viewing side.

[0022] For example, when right-handed circularly polarized light is incident from the lens 600 side, the right-handed circularly polarized light that has passed through the lens 600 and the adhesive layer 23 is converted into linearly polarized light by the retardation layer 21. As an example, the description will be given assuming that the light is converted into linearly polarized light in the horizontal direction in the figure. This linearly polarized light passes through the adhesive layer 101 and enters the linear reflective polarizer 102. For example, if the linear reflective polarizer 102 reflects linearly polarized light in the horizontal direction in the figure and transmits linearly polarized light perpendicular to the paper surface in the figure, the linearly polarized light in the horizontal direction that has entered the linearly reflective polarizer 102 is reflected. The reflected linearly polarized light in the horizontal direction passes through the adhesive layer 101 and enters the retardation layer 21. The retardation layer 21 converts the linearly polarized light in the horizontal direction into right-handed circularly polarized light and transmits it. This right-handed circularly polarized light passes through the adhesive layer 23 and the lens 600. The transmitted light is incident on, for example, a half mirror.

[0023] Here, a portion of the right-handed circularly polarized light reflected by the linear reflective polarizer 102 and converted by the retardation layer 21 is reflected at the interface between the retardation layer 21 and the adhesive layer 23. Even in a configuration without the adhesive layer 23, this circularly polarized light is reflected at the interface between the retardation layer 21 and another layer. The right-handed circularly polarized light reflected at the interface changes its direction of rotation to the opposite direction. That is, the right-handed circularly polarized light reflected at the interface is converted into left-handed circularly polarized light. This left-handed circularly polarized light is converted by the retardation layer 21 into linearly polarized light in a direction perpendicular to the paper surface in the figure. This linearly polarized light passes through the adhesive layer 101 and enters the linearly reflective polarizer 102. However, because the linearly reflective polarizer 102 has a transmission axis in a direction perpendicular to the paper surface, the linearly polarized light in the direction perpendicular to the paper surface passes through the linearly reflective polarizer 102 and exits to the viewing side. As such, in the conventional configuration, unnecessary light reflected at the interface exits to the viewing side, resulting in a visually perceived ghost.

[0024] Next, a configuration of the present invention using a retardation film having an optical interference layer will be described with reference to FIG.

[0025] 7 shows an example in which a retardation film 11 having a retardation layer 21, an optical interference layer 22, and an adhesive layer 23 is laminated on a lens 600 on the adhesive layer 23 side, and a linear reflective polarizer 102 is laminated on the retardation layer 21 side via an adhesive layer 101. Such a configuration corresponds to an optical article used in a virtual reality display device described later, and is used as a reciprocating optical system (folding optical system) in combination with a half mirror. When used as a reciprocating optical system, the upper side (lens 600 side) in FIG. 7 is the image display device side, and the lower side (linear reflective polarizer 102 side) is the viewing side.

[0026] For example, when right-handed circularly polarized light is incident from the lens 600 side, the right-handed circularly polarized light that has passed through the lens 600, the adhesive layer 23, and the optical interference layer 22 is converted into linearly polarized light by the retardation layer 21. As an example, the description will be given assuming that the light is converted into linearly polarized light in the horizontal direction in the figure. This linearly polarized light passes through the adhesive layer 101 and enters the linear reflective polarizer 102. For example, if the linear reflective polarizer 102 reflects linearly polarized light in the horizontal direction in the figure and transmits linearly polarized light perpendicular to the paper surface in the figure, the linearly polarized light that has entered the linearly reflective polarizer 102 in the horizontal direction is reflected. The reflected linearly polarized light in the horizontal direction passes through the adhesive layer 101 and enters the retardation layer 21. The retardation layer 21 converts the linearly polarized light in the horizontal direction into right-handed circularly polarized light and transmits it. This right-handed circularly polarized light passes through the optical interference layer 22, the adhesive layer 23, and the lens 600. The transmitted light is then incident on, for example, a half mirror.

[0027] Furthermore, a portion of the right-handed circularly polarized light reflected by the linear reflective polarizer 102 and converted by the retardation layer 21 is reflected at the interface between the retardation layer 21 and the optical interference layer 22 (reflected light I1 in the figure). Another portion of the right-handed circularly polarized light is also reflected at the interface between the optical interference layer 22 and the adhesive layer 23 (reflected light I2 in the figure). The right-handed circularly polarized light I1 and I2 reflected at each interface change their rotation direction in opposite directions. That is, the right-handed circularly polarized light I1 and I2 reflected at the interface are each converted to left-handed circularly polarized light. The left-handed circularly polarized light I1 and I2 are converted by the retardation layer 21 into linearly polarized light perpendicular to the paper surface in the figure. This linearly polarized light passes through the adhesive layer 101 and enters the linearly reflective polarizer 102. However, because the linearly reflective polarizer 102 has a transmission axis perpendicular to the paper surface, the linearly polarized light perpendicular to the paper surface passes through the linearly reflective polarizer 102 and exits to the viewing side.

[0028] Here, the reflected light I1 reflected at the interface between the retardation layer 21 and the optical interference layer 22 and the reflected light I2 reflected at the interface between the optical interference layer 22 and the adhesive layer 23 have different optical path lengths, and therefore interference occurs. Depending on the difference between the optical path lengths of the reflected light I1 and the reflected light I2 (i.e., the amount of phase shift), the reflected light I1 and the reflected light I2 may constructively or destructively interfere with each other. In the present invention, by setting the film thickness of the optical interference layer 22 to 60 nm to 110 nm or 230 nm to 330 nm, the reflected light I1 and the reflected light I2 are destructively interfered with each other, and it is possible to prevent unnecessary light reflected at the interface from being emitted to the viewing side, thereby reducing ghosts.

[0029] The film thickness of the light interference layer 22 is determined taking into consideration the fact that, while light is incident on the interface from the front and oblique directions, the vicinity of the front is particularly important for interfacial reflection, that light with a wavelength of around 550 nm contributes significantly to the visibility of ghosts, and the refractive index of the light interference layer 22, so that reflected light I1 and reflected light I2 weaken each other near the front and at a wavelength of around 550 nm, i.e., so that the phases of reflected light I1 and reflected light I2 are shifted by approximately λ / 2 or approximately 3λ / 2.

[0030] [Retardation Layer] The retardation layer used in the present invention is a retardation plate having the function of converting linearly polarized light of a certain wavelength into circularly polarized light (or circularly polarized light into linearly polarized light). More specifically, it is a plate exhibiting an in-plane retardation Re of λ / 4 (or an odd multiple thereof) at a predetermined wavelength λ nm. The in-plane retardation (Re(550)) of the retardation layer at a wavelength of 550 nm may have an error of about 25 nm around the ideal value (137.5 nm), and is, for example, preferably 110 to 160 nm, more preferably 120 to 150 nm.

[0031] The retardation layer used in the present invention preferably exhibits the characteristics of a λ / 4 plate at each wavelength across the visible light range, and such a retardation layer is particularly called a broadband λ / 4 plate.The broadband λ / 4 plate preferably has an in-plane retardation (Re(λ)) at a wavelength of λ nm that satisfies the following formulas (A) and (B): Formula (A) Re(450) / Re(550)<1.00 Formula (B) Re(650) / Re(550)≧1.00Re(450) represents the in-plane retardation of the λ / 4 plate at a wavelength of 450 nm, Re(550) represents the in-plane retardation of the λ / 4 plate at a wavelength of 550 nm, and Re(650) represents the in-plane retardation of the λ / 4 plate at a wavelength of 650 nm.

[0032] The retardation layer used in the present invention may be composed of a single retardation layer, or may be composed of two or more retardation layers laminated by lamination, sequential formation, or other methods. The retardation layer referred to here is a layer that exhibits optical anisotropy. Examples of the retardation layer include layers in which at least two of nx, ny, and nz are different. Note that nx represents the refractive index in the direction perpendicular to the thickness direction of the retardation layer (in-plane direction) and in the direction that gives the maximum refractive index. ny represents the refractive index in the in-plane direction of the retardation layer and in the direction perpendicular to the nx direction. nz represents the refractive index in the thickness direction of the retardation layer.

[0033] The material constituting the retardation layer used in the present invention is not particularly limited, and examples thereof include liquid crystal compounds and polymers. A liquid crystal compound can form a retardation layer by orienting a liquid crystal material to exhibit refractive index anisotropy. A polymer can form a retardation layer by exhibiting refractive index anisotropy through stretching a polymer film obtained by casting, coating, or the like. The retardation layer used in the present invention is preferably a layer formed using a liquid crystal compound in terms of thinness, and more preferably a layer formed using a liquid crystal compound having a polymerizable group.

[0034] The type of liquid crystal compound is not particularly limited. Generally, liquid crystal compounds can be classified into rod-shaped (rod-shaped liquid crystal compounds) and discotic (discotic liquid crystal compounds) based on their shape. Furthermore, liquid crystal compounds can be classified into low-molecular-weight and high-molecular-weight compounds. A polymer generally refers to a compound with a degree of polymerization of 100 or more (see "Polymer Physics: Phase Transition Dynamics," by Masao Doi, p. 2, Iwanami Shoten, 1992). While any liquid crystal compound can be used in the present invention, rod-shaped or discotic liquid crystal compounds are preferred, and rod-shaped liquid crystal compounds are even more preferred. Two or more rod-shaped liquid crystal compounds, two or more discotic liquid crystal compounds, or a mixture of rod-shaped and discotic liquid crystal compounds may also be used. Examples of rod-shaped liquid crystal compounds include those described in claim 1 of JP-A-11-513019 and paragraphs 0026 to 0098 of JP-A-2005-289980. Examples of discotic liquid crystal compounds include the liquid crystal compounds described in paragraphs 0020 to 0067 of JP-A No. 2007-108732 and paragraphs 0013 to 0108 of JP-A No. 2010-244038.

[0035] The liquid crystal compound preferably has a polymerizable group. In other words, the liquid crystal compound is preferably a polymerizable liquid crystal compound. When the liquid crystal compound has a polymerizable group, the alignment state of the liquid crystal compound can be easily fixed by a curing treatment described later. The type of polymerizable group possessed by the liquid crystal compound is not particularly limited, and a functional group capable of an addition polymerization reaction is preferred, a polymerizable ethylenically unsaturated group or a ring-polymerizable group is more preferred, and a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group is even more preferred. The number of polymerizable groups possessed by the liquid crystal compound is not particularly limited, but is preferably 2 or more. The upper limit is not particularly limited, but is often 10 or less.

[0036] The liquid crystal compound may be a liquid crystal compound exhibiting either forward wavelength dispersion or reverse wavelength dispersion. When a retardation layer exhibiting the characteristics of a wideband λ / 4 plate as a single film is used, a liquid crystal compound exhibiting reverse wavelength dispersion is preferred, and a liquid crystal compound having two or more polymerizable groups and exhibiting reverse wavelength dispersion is more preferred. In this specification, "liquid crystal compound exhibiting reverse wavelength dispersion" refers to a compound that satisfies the relationship of the above formula (A) and formula (B) when the in-plane retardation (Re) value at a specific wavelength (visible light range) of an optically anisotropic layer prepared using this compound is measured. In addition, in this specification, "liquid crystal compound exhibiting forward wavelength dispersion" refers to a compound that satisfies the relationship of the following formula (C) and formula (D) when the in-plane retardation (Re) value at a specific wavelength (visible light range) of a retardation layer prepared using this compound is measured. Formula (C) Re(450) / Re(550)≧1.00 Formula (D) Re(650) / Re(550)<1.00

[0037] As described above, the retardation layer is preferably a layer formed using a liquid crystal compound having a polymerizable group, and more preferably a layer formed by fixing the orientation state of a liquid crystal compound having a polymerizable group. The orientation state that a liquid crystal compound having a polymerizable group can assume is not particularly limited, and examples thereof include homogeneous orientation, homeotropic orientation, twisted orientation, cholesteric orientation, hybrid orientation (orientation in which the tilt angle of the liquid crystal compound changes continuously from one surface to the other), and tilted orientation (orientation in which the tilt angle of the liquid crystal compound is constant from one surface to the other). Note that twisted orientation refers to an orientation state in which the liquid crystal compound is twisted around the thickness direction as the rotation axis, and when the liquid crystal compound is twisted and has a predetermined tilt angle (tilt angle greater than 0°), it corresponds to twist hybrid orientation. Note that, in this specification, twisted orientation refers to an embodiment in which the twist angle of the liquid crystal compound is less than 360°, and cholesteric orientation refers to an embodiment in which the twist angle of the liquid crystal compound is 360° or more. The "fixed" state is a state in which the alignment of the liquid crystal compound is maintained, which is the most typical and preferred embodiment. However, it is not limited thereto, and specifically, it is more preferred that the layer has no fluidity and the alignment state is not changed by an external field or external force, and the fixed alignment state can be stably maintained, usually in a temperature range of 0 to 50°C, or under more severe conditions in a temperature range of −30 to 70°C.

[0038] The retardation layer formed using a liquid crystal compound may have a plurality of regions in the thickness direction where the liquid crystal compound has different alignment states. For example, the retardation layer may have a region in which the liquid crystal compound is fixed in a homogeneously aligned state and a region in which the liquid crystal compound is fixed in a twisted aligned state, along the thickness direction.

[0039] The thickness of the retardation layer is not particularly limited, but is preferably 0.1 to 10.0 μm, more preferably 0.5 to 5.0 μm.

[0040] Specific examples of the configuration of a wideband λ / 4 plate include those configured with a single-layer retardation layer, such as retardation layers using liquid crystal compounds exhibiting reverse wavelength dispersion as disclosed in International Publication WO2019 / 160016, JP2020-173460, and International Publication WO2021 / 157694, and retardation layers having multiple regions along the thickness direction in which the alignment states of liquid crystal compounds are different as disclosed in International Publication WO2022 / 030308 and JP2022-184691. Examples of a laminate of two or more retardation layers include a configuration that combines a λ / 4 retardation layer and a λ / 2 retardation layer as disclosed in JP-A-2001-108825, JP-A-2001-091741, International Publication WO2013 / 137464, etc., and a configuration that combines a retardation layer having a twisted orientation with another retardation layer as disclosed in JP-A-2001-021720, JP-A-2014-209219, International Publication WO2022 / 255105, etc. In addition, in order to compensate for the phase difference change with respect to obliquely incident light, other retardation layers such as a positive C plate and a negative C plate may be further added.

[0041] [Light Interference Layer] The retardation film of the present invention includes a light interference layer. The light interference layer may be composed of a single light interference layer, or may be composed of two or more light interference layers laminated together by lamination, sequential formation, or other techniques. The film thickness of the single light interference layer is preferably in the range of 60 nm to 110 nm or 230 nm to 330 nm, more preferably in the range of 75 nm to 100 nm or 245 nm to 300 nm, and most preferably in the range of 80 nm to 95 nm or 260 nm to 285 nm. When using a typical liquid crystal material and adhesive layer, their refractive indices are approximately 1.625 and approximately 1.5, respectively. Therefore, the refractive index of the light interference layer is preferably 1.50 to 1.70, more preferably 1.53 to 1.59. For adhesive layers and retardation layers with any refractive index, the preferred range of the light interference layer can be generalized using the average refractive index of the adhesive layer and retardation layer, and it is preferable that the following conditions are satisfied. That is, when the refractive index of the adhesive layer adjacent to the optical interference layer is nA and the average refractive index of the retardation layer is nL, the refractive index nI of the optical interference layer is (nA × nL) １／２ −0.03≦nI≦(nA×nL) １／２ +0.03, (nA × nL) １／２ −0.02≦nI≦(nA×nL) １／２ +0.02 is more preferable, (nA × nL) １／２ −0.01≦nI≦(nA×nL) １／２ It is most preferable that the refractive index of the optical interference layer is +0.01. By setting the refractive index of the optical interference layer within this range, the amplitude reflectance on both sides of the optical interference layer can be made approximately the same, which is thought to result in a significant anti-reflection effect. This makes it possible to suppress reflected light caused by interfacial reflection. Reflected light whose rotation direction has changed due to interfacial reflection is one of the causes of ghosting, so it is thought that suppressing interfacial reflection can suppress the occurrence of ghosting. The refractive indexes of the optical interference layer, retardation layer, and adhesive layer can be measured with reference to the methods described in the examples.

[0042] When forming the light interference layer, it may be formed on a retardation layer, or a light interference layer may be formed first on a temporary support and then the retardation layer may be formed thereon. Materials for forming the light interference layer include a hard coat material crosslinked from a monomer, a photo-alignment film, and a C-plate made of a liquid crystal material. Of these, a photo-alignment film is more preferred because it also plays a role in aligning liquid crystals when a retardation layer is formed on top of it using a liquid crystal material. Furthermore, of these, a C-plate is more preferred because it also plays a role in adjusting optical compensation. A positive C-plate is even more preferred. Here, a positive C-plate is a retardation layer having an Re of substantially zero and a negative Rth value. A positive C-plate can be obtained, for example, by vertically aligning a rod-shaped liquid crystal compound. Details of the manufacturing method of a positive C-plate can be found in, for example, JP 2017-187732 A, JP 2016-053709 A, and JP 2015-200861 A.

[0043] [Photo-Alignment Film Material] A preferred embodiment of the optical interference layer is a so-called photo-alignment film (photo-alignment layer) formed by irradiating a photo-alignable material with polarized or non-polarized light to form an alignment layer. It is preferable to impart alignment control force to the photo-alignment film by a process of irradiating polarized light from a vertical or oblique direction, or a process of irradiating non-polarized light from an oblique direction. By using a photo-alignment film, it is possible to horizontally align specific liquid crystal compounds with excellent symmetry. Therefore, a retardation layer positive A plate formed using a photo-alignment film is useful for optical compensation in liquid crystal displays that do not require a pre-tilt angle of the driving liquid crystal, such as IPS (In-Place-Switching) mode liquid crystal displays. Examples of photo-alignment materials used in the photo-alignment film include those described in JP-A-2006-285197, JP-A-2007-076839, JP-A-2007-138138, JP-A-2007-094071, JP-A-2007-121721, JP-A-2007-140465, and JP-A-2007-156439. Azo compounds described in JP-A Nos. 2007-133184, 2009-109831, 3883848, and 4151746, aromatic ester compounds described in JP-A No. 2002-229039, and photo-alignable units described in JP-A Nos. 2002-265541 and 2002-317013 Maleimide and / or alkenyl-substituted nadimide compounds, photocrosslinkable silane derivatives described in Japanese Patent Nos. 4205195 and 4205198, photocrosslinkable polyimides, polyamides, or esters described in JP-T-2003-520878, JP-T-2004-529220, and JP-T-4162850, photodimerizable compounds described in JP-A-9-118717, JP-A-10-506420, JP-A-2003-505561, WO 2010 / 150748, JP-A-2013-177561, and JP-A-2014-012823, in particular cinnamate compounds, chalcone compounds, and coumarin compounds. Particularly preferred examples include azo compounds, photocrosslinkable polyimides, polyamides, esters, cinnamate compounds, and chalcone compounds.

[0044] [Material for interlayer photo-alignment film] The optical interference layer preferably contains a material for an interlayer photo-alignment film. This allows liquid crystal alignment when a liquid crystal material is applied onto the optical interference layer, and a structure in which the optical interference layer and the light-reflecting layer are adjacent to each other can be formed. As the material for the interlayer photo-alignment film, the photo-alignable polymer described in JP 2021-143336 A can be used. The material for the interlayer photo-alignment film is preferably a compound having a cinnamoyl group. The cinnamoyl compound is preferably contained between the optical interference layer (preferably a C-plate) and the retardation layer. In other words, the cinnamoyl compound is preferably contained in a region near the boundary between the optical interference layer (preferably a C-plate) and the retardation layer.

[0045] [Adhesive Layer] The adhesive layer can be made of any known adhesive or pressure-sensitive adhesive, as long as it has a refractive index that satisfies the above-mentioned relationship. For example, the adhesive and / or pressure-sensitive adhesive used in the laminated optical film described below can be used. Any commercially available pressure-sensitive adhesive can be used for the adhesive layer. However, from the viewpoint of thinning and reducing the surface roughness (Ra), the thickness is preferably 25 μm or less, more preferably 15 μm or less, and most preferably 6 μm or less. Furthermore, it is preferable that the pressure-sensitive adhesive is less likely to outgas. In particular, when performing stretching and molding, vacuum processes and heating processes may be used, and it is preferable that the pressure-sensitive adhesive does not outgas even under these conditions. Any commercially available adhesive can be used for the adhesive layer. For example, epoxy resin adhesives and acrylic resin adhesives can be used. From the viewpoint of thinning and reducing the surface roughness Ra of the linear reflective polarizer used in the laminated optical film, the adhesive preferably has a thickness of 25 μm or less, more preferably 5 μm or less, and most preferably 1 μm or less. Furthermore, from the viewpoint of thinning the adhesive layer and applying the adhesive to the adherend with a uniform thickness, the adhesive preferably has a viscosity of 300 cP or less, more preferably 100 cP or less. Furthermore, when the adherend has surface irregularities, the pressure-sensitive adhesive and adhesive can be selected to have an appropriate viscoelasticity or thickness so as to embed the surface irregularities of the layer to be adhered, from the viewpoint of reducing the surface roughness Ra of the linear reflective polarizer used in the laminated optical film. From the viewpoint of embedding the surface irregularities, the pressure-sensitive adhesive and adhesive preferably have a viscosity of 50 cP or more. Furthermore, the thickness is preferably greater than the height of the surface irregularities. A method for adjusting the viscosity of the adhesive can be, for example, a method using an adhesive containing a solvent. In this case, the viscosity of the adhesive can be adjusted by changing the ratio of the solvent. Furthermore, by drying the solvent after applying the adhesive to the adherend, the thickness of the adhesive can be further reduced.

[0046] In a laminated optical film, from the viewpoint of reducing reflection at the interface and suppressing the occurrence of ghosts, it is preferable that the pressure-sensitive adhesive or adhesive used for bonding each layer has a small difference in refractive index with the adjacent layer. Since the retardation layer has birefringence and therefore has different refractive indices in the fast axis direction and the slow axis direction, the average refractive index n of the liquid crystal layer is determined by adding the refractive indices in the fast axis direction and the slow axis direction and dividing the sum by 2. ａｖｅ When the refractive index of the adjacent adhesive layer or bonding layer is n ａｖｅ The difference between these refractive indices is preferably 0.075 or less, more preferably 0.05 or less, and even more preferably 0.025 or less. The refractive index of the pressure-sensitive adhesive or adhesive can be adjusted by mixing, for example, titanium oxide fine particles and zirconia fine particles.

[0047] It is also preferable that the adhesive layer between each layer has a thickness of 100 nm or less. When the adhesive layer is 100 nm or less, the refractive index difference is less noticeable for visible light, suppressing unnecessary reflection. The adhesive layer thickness is more preferably 50 nm or less, and even more preferably 30 nm or less. An example of a method for forming an adhesive layer having a thickness of 100 nm or less is vapor deposition of a ceramic adhesive such as silicon oxide (SiOx layer) onto the bonding surface. The bonding surface of the bonding member can be subjected to surface modification treatments such as plasma treatment, corona treatment, and saponification treatment before bonding, and a primer layer can be applied. Furthermore, when there are multiple bonding surfaces, the type and thickness of the adhesive layer can be adjusted for each bonding surface. Specifically, an adhesive layer having a thickness of 100 nm or less can be formed, for example, by the following steps (1) to (3): (1) The layers to be laminated are bonded to a temporary support made of a glass substrate. (2) A SiOx layer having a thickness of 100 nm or less is formed on both the surface of the layer to be laminated and the surface of the layer to be laminated by vapor deposition or the like. Vapor deposition can be performed using, for example, a vapor deposition device manufactured by ULVAC (model number ULEYES) using SiOx powder as the vapor deposition source. It is also preferable to subject the surface of the formed SiOx layer to plasma treatment. (3) After the formed SiOx layers are bonded together, the temporary support is peeled off. The bonding is preferably performed at a temperature of, for example, 120°C.

[0048] The coating, adhesion, or lamination of each layer may be performed by roll-to-roll or sheet-fed. The roll-to-roll method is preferred from the viewpoint of improving productivity and reducing axial misalignment of each layer. On the other hand, the sheet-fed method is preferred because it is suitable for small-lot, high-mix production and because it allows the selection of a special adhesion method such as the above-mentioned adhesive layer thickness of 100 nm or less. Furthermore, examples of methods for applying the adhesive to the adherend include known methods such as roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet printing.

[0049] The retardation film of the present invention may include a support and an alignment layer, but the support and alignment layer may be a temporary support that is peeled off and removed when producing the laminated optical film described below. When a temporary support is used, the retardation film is transferred to another laminated optical film, and then the temporary support is peeled off and removed, thereby making it possible to thin the laminated optical film. Furthermore, this is preferable because it is possible to eliminate the adverse effect that the retardation of the temporary support has on the polarization degree of transmitted light. The type of support is not particularly limited, but it is preferably transparent to visible light. For example, films such as cellulose acylate, polycarbonate, polysulfone, polyethersulfone, polyacrylate and polymethacrylate, cyclic polyolefin, polyolefin, polyamide, polystyrene, and polyester can be used. Among these, cellulose acylate film, cyclic polyolefin, polyacrylate, or polymethacrylate are preferred. Commercially available cellulose acetate films (e.g., "TD80U" and "Z-TAC" manufactured by Fujifilm Corporation) can also be used. When the support is a temporary support, a support with high tear strength is preferred from the viewpoint of preventing breakage during peeling. For example, polycarbonate and polyester films are preferred. In addition, the support preferably has a small retardation from the viewpoint of suppressing adverse effects on the polarization degree of transmitted light. Specifically, the magnitude of Re at 550 nm is preferably 10 nm or less, and the absolute value of Rth is preferably 50 nm or less. In addition, even if the support is used as the above-mentioned temporary support, it is preferable that the retardation of the temporary support is small in order to perform quality inspection of the retardation film and the laminated optical film in the manufacturing process of the laminated optical film described below.

[0050] Furthermore, in order to minimize the influence on various sensors that use near-infrared light as a light source, such as those for eye tracking, facial expression recognition, and iris authentication, which are incorporated into optical systems such as virtual reality display devices and electronic viewfinders, the retardation film used in the laminated optical film described below is preferably transparent to near-infrared light.

[0051] [Laminated Optical Film] The laminated optical film of the present invention preferably has at least a retardation film that converts circularly polarized light into linearly polarized light and a linear reflective polarizer in this order. The retardation film is the above-mentioned retardation film. Preferred embodiments of the retardation film are as described above. The linear reflective polarizer is preferably arranged on the opposite side of the retardation layer from the light interference layer.

[0052] As a suitable example of the use of the laminated optical film of the present invention, a virtual reality display device using the laminated optical film of the present invention will be taken up and the function of the laminated optical film of the present invention will be described in detail.

[0053] 3 is a schematic diagram of a virtual reality display device using the laminated optical film of the present invention. In the virtual reality display device of the embodiment shown in FIG. 3, a laminated optical film 100 having the above-mentioned retardation film and linear reflective polarizer, a half mirror 300, a circular polarizing plate 400, and an image display panel 500 are arranged in this order from the viewing side. As shown in FIG. 3, a light ray 1000 emitted from the image display panel 500 passes through the circular polarizing plate 400 to become circularly polarized light and then passes through the half mirror 300. Next, by passing through the retardation film of the laminated optical film 100 of the present invention, the light ray is converted into linearly polarized light parallel to the reflection axis of the linear reflective polarizer, and then reflected by the linear reflective polarizer. Next, the light ray is reflected again by the half mirror 300 and again enters the laminated optical film 100. At this time, the polarization state of the light ray 1000 is circularly polarized light with a rotation direction opposite to that of the circularly polarized light when it first entered the laminated optical film 100 due to reflection by the half mirror. When this polarized light passes through the retardation film of the laminated optical film, it is converted into linearly polarized light parallel to the transmission axis of the linearly reflective polarizer. As a result, the light ray 1000 passes through the laminated optical film 100 and is visible to the user. Furthermore, when the light ray 1000 is reflected by the half mirror 300, the image displayed on the image display panel 500 is enlarged due to the half mirror's concave shape, allowing the user to view the enlarged virtual image. The above-described mechanism is called a reciprocating optical system or a folded optical system. Meanwhile, FIG. 4 is a schematic diagram illustrating a case in which a ghost occurs in the virtual reality display device shown in FIG. 3. More specifically, this is a schematic diagram illustrating a case in which a light ray 2000 is incident on the laminated optical film 100 for the first time, is not reflected by the half mirror, and is transmitted, resulting in leakage light. As shown in Figure 4, when a light ray 2000 is incident on the laminated optical film 100 for the first time, it passes through the half mirror without being reflected, and if light leakage occurs, the user will see an unmagnified image, as can be seen from Figure 4. This image is called a ghost or the like, and it is necessary to suppress it.There are two main causes of this light leakage (ghosting): one is due to a phase difference in the reflective polarizer, and the other is the occurrence of light leakage (ghosting) due to a change in the rotation direction caused by interfacial reflection, as previously described in FIG. 6 . The laminated optical film 100 of the present invention has a high degree of polarization, and therefore can reduce leakage of transmitted light (i.e., ghosting) when a light ray is incident on the laminated optical film 100 for the first time. Furthermore, the laminated optical film 100 of the present invention also has a high degree of polarization for transmitted light, and therefore can increase the transmittance when a light ray is incident on the laminated optical film 100 for the second time, thereby improving the brightness of the virtual image and further suppressing coloring of the virtual image.

[0054] The laminated optical film 100 is preferably curved as shown in Figures 3 and 4. The curved laminated optical film 100 may be configured such that the laminated optical film 100 itself is formed into a curved shape, or may be curved by being laminated on the surface of a member having a curved surface, such as a lens 600, as shown in Figure 8.

[0055] An example of the layer structure of the laminated optical film 100 of the present invention is shown in FIG. 5. The laminated optical film 100 shown in FIG. 5 has a retardation film 11, an adhesive layer 101, a linear reflective polarizer 102, an adhesive layer 103, and a linear polarizer 104 arranged in this order. As described above, the retardation film 11 has a retardation layer 21, an optical interference layer 22, and an adhesive layer 23. The linear polarizer 104 is preferably an absorptive linear polarizer. The laminated optical film of the present invention has a retardation layer 11, a linear reflective polarizer 102, and a linear polarizer 104, which convert circularly polarized light into linearly polarized light, in this order, so that transmitted light from the linear reflective polarizer 102 can be absorbed by the linear polarizer. Therefore, the degree of polarization of the transmitted light can be increased.

[0056] Furthermore, the laminated optical film of the present invention preferably has a surface roughness Ra of 100 nm or less. A small Ra can improve the sharpness of images, for example, when the laminated optical film is used in a virtual reality display device or the like. The present inventors have estimated that when light is reflected from the laminated optical film, unevenness distorts the angle of the reflected light, leading to image distortion and blurring. The Ra of the laminated optical film is more preferably 50 nm or less, even more preferably 30 nm or less, and particularly preferably 10 nm or less. The laminated optical film of the present invention is produced by laminating multiple layers. According to the inventors' studies, it has been found that laminating another layer on an uneven layer can amplify the unevenness. Therefore, in the laminated optical film of the present invention, it is preferable that all layers have a small Ra. Each layer of the laminated optical film of the present invention preferably has an Ra of 50 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less. From the viewpoint of improving the image sharpness of the reflected image, it is particularly preferable that the Ra of the linear reflective polarizer is small. The surface roughness Ra can be measured, for example, using a non-contact surface / layer cross-sectional shape measurement system, VertScan (manufactured by Ryoka Systems Co., Ltd.). Since VertScan is a surface shape measurement method that utilizes the phase of reflected light from a sample, when measuring a linear reflective polarizer, reflected light from inside the film may be superimposed, making it impossible to accurately measure the surface shape. In this case, a metal layer may be formed on the surface of the sample to increase the reflectance of the surface and further suppress reflection from inside. For example, a sputtering method is used as a method for forming a metal layer on the surface of the sample. Examples of materials that can be sputtered include Au, Al, and Pt.

[0057] The laminated optical film of the present invention preferably has a small number of point defects per unit area. Since the laminated optical film of the present invention is produced by stacking multiple layers, it is preferable that the number of point defects in each layer is also small in order to reduce the number of point defects in the entire laminated optical film. Specifically, the number of point defects in each layer is preferably 20 or less per square meter, more preferably 10 or less, and even more preferably 1 or less. For the entire laminated optical film, the number of point defects is preferably 100 or less per square meter, more preferably 50 or less, and even more preferably 5 or less. Point defects lead to a decrease in the degree of polarization of transmitted light and a decrease in image sharpness, so it is preferable that they are small. Here, point defects include foreign matter, scratches, dirt, film thickness fluctuations, poor alignment of liquid crystal compounds, etc. Furthermore, the number of point defects described above is preferably counted as the number of point defects with a size of 100 μm or more, more preferably 30 μm or more, and most preferably 10 μm or more.

[0058] In addition, various sensors using near-infrared light as a light source, such as for eye tracking, facial expression recognition, and iris authentication, may be incorporated into optical systems such as virtual reality display devices and electronic viewfinders, and in order to minimize the influence on the sensors, it is preferable that the laminated optical film of the present invention is transparent to near-infrared light.

[0059] [Linear Polarizer] The linear polarizer used in the laminated optical film of the present invention is preferably an absorption-type linear polarizer. An absorption-type linear polarizer absorbs linearly polarized light in the absorption axis direction of incident light and transmits linearly polarized light in the transmission axis direction. A typical polarizer can be used as the linear polarizer. For example, a polarizer obtained by dyeing a dichroic material onto polyvinyl alcohol or other polymer resin and stretching it to orient the material may be used. Alternatively, a polarizer obtained by aligning a dichroic material by utilizing the orientation of a liquid crystal compound may be used. From the viewpoints of availability and increasing the polarization degree, a polarizer obtained by dyeing polyvinyl alcohol with iodine and stretching it is preferred. The thickness of the linear polarizer is preferably 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less. A thin linear polarizer can prevent cracking and breakage of the film when the laminated optical film is stretched or molded. The single-plate transmittance of the linear polarizer is preferably 40% or more, more preferably 42% or more. The degree of polarization is preferably 90% or more, more preferably 95% or more, and even more preferably 99% or more. In this specification, the single-plate transmittance and degree of polarization of the linear polarizer are measured using an automatic polarizing film measuring device: VAP-7070 (manufactured by JASCO Corporation). The direction of the transmission axis of the linear polarizer preferably coincides with the direction of the polarization axis of light converted into linearly polarized light by the retardation layer. For example, when the retardation layer is a layer having a retardation of 1 / 4 wavelength, the angle between the transmission axis of the linear polarizer and the slow axis of the retardation layer is preferably approximately 45°.

[0060] The linear polarizer used in the laminated optical film of the present invention is also preferably a light-absorbing anisotropic layer containing a liquid crystal compound and a dichroic material. Linear polarizers containing a liquid crystal compound and a dichroic material are preferred because they can be made thin and are less likely to crack or break even when stretched and molded. The thickness of the light-absorbing anisotropic layer is not particularly limited, but from the viewpoint of thinning, it is preferably 0.1 to 8 μm, more preferably 0.3 to 5 μm. Linear polarizers containing a liquid crystal compound and a dichroic material can be produced, for example, with reference to JP 2020-023153 A. From the viewpoint of improving the polarization degree of the linear polarizer, the light-absorbing anisotropic layer preferably has an orientation degree of the dichroic material of 0.95 or more, more preferably 0.97 or more.

[0061] The liquid crystal compound contained in the composition for forming the optically absorptive anisotropic layer is preferably a liquid crystal compound that does not exhibit dichroism in the visible range. Both low-molecular-weight liquid crystal compounds and high-molecular-weight liquid crystal compounds can be used as the liquid crystal compound. Here, "low-molecular-weight liquid crystal compound" refers to a liquid crystal compound that does not have a repeating unit in its chemical structure. Furthermore, "high-molecular-weight liquid crystal compound" refers to a liquid crystal compound that has a repeating unit in its chemical structure. Examples of high-molecular-weight liquid crystal compounds include the thermotropic liquid crystal polymers described in JP 2011-237513 A. Furthermore, high-molecular-weight liquid crystal compounds preferably have a crosslinkable group (e.g., an acryloyl group or a methacryloyl group) at their terminals. The liquid crystal compounds may be used alone or in combination. It is also preferable to use a high-molecular-weight liquid crystal compound and a low-molecular-weight liquid crystal compound in combination. The content of the liquid crystal compound is preferably 25 to 2,000 parts by weight, more preferably 33 to 1,000 parts by weight, and even more preferably 50 to 500 parts by weight, per 100 parts by weight of the dichroic substance in the composition. When the content of the liquid crystal compound is within the above range, the degree of orientation of the polarizer is further improved.

[0062] The dichroic substance contained in the composition for forming an optically absorptive anisotropic layer for forming the optically absorptive anisotropic layer is not particularly limited, and examples thereof include visible light absorbing substances (dichroic dyes), ultraviolet absorbing substances, infrared absorbing substances, nonlinear optical substances, carbon nanotubes, etc., and any conventionally known dichroic substance (dichroic dye) can be used. In the present invention, two or more dichroic substances may be used in combination. For example, from the viewpoint of obtaining a high degree of polarization over a wider wavelength range, it is preferable to use in combination at least one dichroic substance having a maximum absorption wavelength in the wavelength range of 370 to 550 nm and at least one dichroic substance having a maximum absorption wavelength in the wavelength range of 500 to 700 nm.

[0063] When the linear polarizer is composed of a light-absorbing anisotropic layer containing a liquid crystal compound and a dichroic material, the linear polarizer may include a support and an alignment layer, etc., but the support and alignment layer may be a temporary support that is peeled off and removed when producing a laminated optical film. Using a temporary support is preferable because the laminated optical film can be thinned by peeling off and removing the temporary support after transferring the light-absorbing anisotropic layer to another laminate, and the adverse effect of the retardation of the temporary support on the polarization degree of transmitted light can be eliminated. The type of support is not particularly limited, but it is preferably transparent to visible light. For example, a support similar to the support used for the retardation layer can be used. Preferred embodiments of the support used for the linear polarizer are the same as those of the support used for the retardation layer.

[0064] Furthermore, in order to minimize the influence on various sensors that use near-infrared light as a light source, such as those for eye tracking, facial expression recognition, and iris authentication, which are incorporated into optical systems such as virtual reality display devices and electronic viewfinders, the linear polarizer used in the laminated optical film of the present invention is preferably transparent to near-infrared light.

[0065] [Other Functional Layers] The laminated optical film of the present invention may have other functional layers in addition to the retardation film, the linear reflective polarizer, and the linear polarizer.

[0066] Furthermore, in order to minimize the influence on various sensors that use near-infrared light as a light source, such as eye tracking, facial expression recognition, and iris authentication, which are incorporated into optical systems such as virtual reality display devices and electronic viewfinders, it is preferable that the other functional layers be transparent to near-infrared light.

[0067] <Positive C Plate> The laminated optical film of the present invention preferably further comprises a positive C plate. Here, the positive C plate is a retardation layer having an Re of substantially zero and an Rth of a negative value. The positive C plate can be obtained, for example, by vertically aligning a rod-shaped liquid crystal compound. For details of the method for producing the positive C plate, see, for example, JP 2017-187732 A, JP 2016-053709 A, and JP 2015-200861 A. The positive C plate functions as an optical compensation layer to increase the degree of polarization of transmitted light with respect to obliquely incident light. The positive C plate can be disposed at any position in the laminated optical film, and multiple positive C plates may be disposed.

[0068] The positive C plate may be disposed adjacent to or inside the retardation film. For example, when a layer formed by immobilizing a rod-shaped liquid crystal compound is used as the retardation film, the retardation layer has a positive Rth. In this case, when light is incident on the retardation layer from an oblique direction, the polarization state of the transmitted light may change due to the action of Rth, resulting in a decrease in the degree of polarization of the transmitted light. Having a positive C plate inside or near the retardation layer is preferable because it can further suppress changes in the polarization state of obliquely incident light and further suppress a decrease in the degree of polarization of the transmitted light, thereby further suppressing ghosting. According to the inventors' studies, the positive C plate is preferably disposed between the lens and the retardation film, but may also be disposed between the retardation film and the linear reflective polarizer, or may be disposed elsewhere. In this case, the Re(550) of the positive C plate is preferably approximately 10 nm or less, and the Rth(550) is preferably -90 to -40 nm.

[0069] <Anti-Reflection Layer> The laminated optical film of the present invention preferably has an anti-reflection layer on its surface. The laminated optical film of the present invention has the function of reflecting specific circularly polarized light and transmitting circularly polarized light orthogonal to it. However, reflection on the surface of the laminated optical film generally includes reflection of unintended polarized light, which may reduce the degree of polarization of the transmitted light. Therefore, it is preferable that the laminated optical film has an anti-reflection layer on its surface. The anti-reflection layer may be provided on only one surface of the laminated optical film or on both surfaces. The type of anti-reflection layer is not particularly limited, but from the viewpoint of further reducing the reflectance, a moth-eye film or an AR (anti-reflective) film is preferred. Known moth-eye films and AR films can be used. Furthermore, when the laminated optical film is stretched or molded, a moth-eye film is preferred because it can maintain high anti-reflection performance even if the film thickness changes due to stretching. Furthermore, when the antireflection layer includes a support and is subjected to stretching, molding, etc., the peak temperature of the glass transition temperature Tg of the support is preferably 170° C. or less, more preferably 130° C. or less, from the viewpoint of facilitating stretching, molding, etc. Specifically, for example, a PMMA film or the like is preferred.

[0070] <Second Retardation Layer> The laminated optical film of the present invention preferably further has a second retardation layer. For example, it may contain a retardation film, a linear reflective polarizer, a linear polarizer, and a second retardation layer in this order. The second retardation layer preferably converts linearly polarized light into circularly polarized light, and for example, a retardation layer having a ¼ wavelength Re is preferred. The reason for this will be explained below. Light incident on the laminated optical film from the retardation film side and transmitted through the linear reflective polarizer and the linear polarizer is linearly polarized light, and a portion of it is reflected by the outermost surface on the linear polarizer side and then exits again from the surface on the retardation film side. Such light is unnecessary reflected light and can be a factor in reducing the degree of polarization of the reflected light, so it is preferable to reduce it. Therefore, there is a method of laminating an antireflection layer to suppress reflection on the outermost surface on the linear polarizer side. However, when the laminated optical film is used by being attached to a medium such as glass or plastic, even if an antireflection layer is provided on the attachment surface of the laminated optical film, reflection on the surface of the medium cannot be suppressed, making it difficult to obtain an antireflection effect. On the other hand, when a second retardation layer that converts linearly polarized light into circularly polarized light is provided, the light that reaches the outermost surface on the linear polarizer side becomes circularly polarized light and is converted into orthogonal circularly polarized light when reflected on the outermost surface of the medium. After that, when the light passes through the second retardation layer again and reaches the linear polarizer, it becomes linearly polarized light in the absorption axis direction of the linear polarizer and is absorbed by the linear polarizer. Therefore, unnecessary reflection can be prevented. From the viewpoint of more effectively suppressing unnecessary reflection, it is preferable that the second retardation layer has substantially reverse dispersion.

[0071] <Support> The laminated optical film of the present invention may further have a support (resin substrate). The support can be installed in any location. For example, when a retardation film, a linear reflective polarizer, or a linear polarizer is a film to be used by transferring it from a temporary support, the support can be used as the transfer destination. The type of support is not particularly limited, but it is preferably transparent to visible light. For example, films such as cellulose acylate, polycarbonate, polysulfone, polyethersulfone, polyacrylate, polymethacrylate, cyclic polyolefin, polyolefin, polyamide, polystyrene, and polyester can be used. Among these, cellulose acylate film, cyclic polyolefin, polyacrylate, or polymethacrylate is preferred. Commercially available cellulose acetate films (for example, "TD80U" and "Z-TAC" manufactured by Fujifilm Corporation) can also be used. Furthermore, it is preferable that the support has a small retardation from the viewpoint of suppressing adverse effects on the polarization degree of transmitted light and from the viewpoint of facilitating optical inspection of the laminated optical film. Specifically, the magnitude of Re is preferably 10 nm or less, and the absolute value of the magnitude of Rth is preferably 50 nm or less.

[0072] When the laminated optical film of the present invention is to be stretched, molded, or the like, the support (resin substrate) preferably has a loss tangent tanδ peak temperature of 170° C. or less. From the viewpoint of enabling molding at low temperatures, the tanδ peak temperature is preferably 150° C. or less, and more preferably 130° C. or less.

[0073] Here, the method for measuring tan δ will be described. Using a dynamic viscoelasticity measuring device (DVA-200 manufactured by IT Measurement Control Co., Ltd.), E" (loss modulus) and E' (storage modulus) are measured under the following conditions for a film sample that has been previously conditioned for at least 2 hours in an atmosphere at a temperature of 25°C and a humidity of 60% Rh, and tan δ (= E" / E') is the value obtained. Device: DVA-200 manufactured by IT Measurement Control Co., Ltd. Sample: 5 mm, length 50 mm (gap 20 mm) Measurement conditions: Tensile mode Measurement temperature: -150°C to 220°C Heating conditions: 5°C / min Frequency: 1 Hz In general, in optical applications, resin substrates that have been subjected to a stretching treatment are often used, and the peak temperature of tan δ often becomes high due to the stretching treatment. For example, the peak temperature of tan δ for a TAC (triacetyl cellulose) substrate (TG40, manufactured by Fujifilm Corporation) is 180°C or higher.

[0074] As a support having a tan δ peak temperature of 170°C or less, various resin substrates can be used without any particular limitation. Examples include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; acrylic resins such as polymethacrylic acid esters and polyacrylic acid esters; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketone; polyphenylene sulfide, and polyphenylene oxide. Among these, in terms of easy commercial availability and excellent transparency, cyclic olefin-based resins, polyethylene terephthalate, and acrylic resins are preferred, and cyclic olefin-based resins and polymethacrylic acid esters are particularly preferred.

[0075] Examples of commercially available resin substrates include Technolloy S001G, Technolloy S014G, Technolloy S000, Technolloy C001, and Technolloy C000 (Sumika Acrylic Sales Co., Ltd.), Lumirror U Type, Lumirror FX10, and Lumirror SF20 (Toray Industries, Inc.), HK-53A (Higashiyama Films Co., Ltd.), Teflex FT3 (Teijin DuPont Films Co., Ltd.), S-Cina and SCA40 (Sekisui Chemical Co., Ltd.), Zeonor Film (Optes Co., Ltd.), and Arton Film (JSR Corporation).

[0076] The thickness of the support is not particularly limited, but is preferably from 5 to 300 μm, more preferably from 5 to 100 μm, and even more preferably from 5 to 30 μm.

[0077] The laminated optical film may also have layers other than those described above. Examples of layers other than those described above include an adhesive layer formed with the adhesive described below, an adhesive layer formed with the adhesive described below, and a refractive index adjustment layer. A refractive index adjustment layer having a smaller difference in refractive index between the fast axis direction and the slow axis direction than that of the retardation layer may be provided between the retardation layer and the adhesive, or between the retardation layer and the adhesive. In this case, the refractive index adjustment layer preferably has a layer that fixes the orientation state of cholesteric liquid crystals. By having a refractive index adjustment layer, interfacial reflection can be further suppressed, and the occurrence of ghosts can be further suppressed. The average refractive index of the refractive index adjustment layer is more preferably smaller than that of the retardation layer.

[0078] [Method of Adhesion of Each Layer] The laminated optical film of the present invention is a laminate composed of multiple layers. Each layer can be bonded by any bonding method, such as a pressure-sensitive adhesive or adhesive. Any commercially available pressure-sensitive adhesive can be used as the pressure-sensitive adhesive. However, from the viewpoint of thinning and reducing the surface roughness Ra of the laminated optical film, the thickness is preferably 25 μm or less, more preferably 15 μm or less, and most preferably 6 μm or less. Furthermore, it is preferable that the pressure-sensitive adhesive is one that is less likely to outgas. In particular, when performing stretching and molding, vacuum processes and heating processes may be used, and it is preferable that the pressure-sensitive adhesive does not outgas even under these conditions. Any commercially available adhesive can be used as the adhesive, such as an epoxy resin adhesive or an acrylic resin adhesive. From the viewpoint of thinning and reducing the surface roughness Ra of the laminated optical film, the thickness of the adhesive is preferably 25 μm or less, more preferably 5 μm or less, and most preferably 1 μm or less. Furthermore, from the viewpoint of thinning the adhesive layer and applying the adhesive to the adherend with a uniform thickness, the adhesive preferably has a viscosity of 300 cP or less, more preferably 100 cP or less, and even more preferably 10 cP or less. Furthermore, if the adherend has surface irregularities, the adhesive, adhesive, etc. can be selected to have an appropriate viscoelasticity or thickness so as to embed the surface irregularities of the layer to be adhered, in order to reduce the surface roughness Ra of the laminated optical film. From the viewpoint of embedding the surface irregularities, the adhesive, adhesive, etc. preferably has a viscosity of 50 cP or more. Furthermore, the thickness is preferably greater than the height of the surface irregularities. For example, a method of adjusting the viscosity of the adhesive can be used, for example, a method of using an adhesive containing a solvent. In this case, the viscosity of the adhesive can be adjusted by adjusting the ratio of the solvent. Furthermore, the thickness of the adhesive can be further reduced by applying the adhesive to the adherend and then drying the solvent.

[0079] In a laminated optical film, from the viewpoint of reducing unnecessary reflection and suppressing a decrease in the degree of polarization of transmitted light and reflected light, it is preferable that the pressure-sensitive adhesive or adhesive used to bond each layer has a small refractive index difference with adjacent layers. Specifically, the refractive index difference between adjacent layers is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.01 or less. The refractive index of the pressure-sensitive adhesive or adhesive can be adjusted, for example, by mixing titanium oxide fine particles and zirconia fine particles. Furthermore, the retardation layer, linear reflective polarizer, and linear polarizer may have in-plane refractive index anisotropy, but it is preferable that the refractive index difference with adjacent layers is 0.05 or less in all directions in the plane. Therefore, the pressure-sensitive adhesive or adhesive may have in-plane refractive index anisotropy.

[0080] It is also preferable that the adhesive layer between each layer has a thickness of 100 nm or less. When the adhesive layer is 100 nm or less, the difference in refractive index is less noticeable for light in the visible range, and reflection at the interface can be suppressed. The adhesive layer thickness is more preferably 50 nm or less. An example of a method for forming an adhesive layer having a thickness of 100 nm or less is a method of depositing a ceramic adhesive such as a silicon oxide (SiOx layer) on the bonding surface. The bonding surface of the bonding member can be subjected to a surface modification treatment such as plasma treatment, corona treatment, or saponification treatment before bonding, or a primer layer can be applied. Furthermore, when there are multiple bonding surfaces, the type and thickness of the adhesive layer can be adjusted for each bonding surface. Specifically, an adhesive layer having a thickness of 100 nm or less can be formed, for example, by the following steps (1) to (3). (1) The layers to be laminated are bonded to a temporary support made of a glass substrate. (2) A SiOx layer having a thickness of 100 nm or less is formed on both the surface of the layer to be laminated and the surface of the layer to be laminated by vapor deposition or the like. Vapor deposition can be performed using, for example, a vapor deposition device manufactured by ULVAC (model number ULEYES) using SiOx powder as the vapor deposition source. It is also preferable to subject the surface of the formed SiOx layer to plasma treatment. (3) After the formed SiOx layers are bonded together, the temporary support is peeled off. The bonding is preferably performed at a temperature of, for example, 120°C.

[0081] The coating, adhesion, or lamination of each layer may be performed by roll-to-roll or sheet-to-sheet. The roll-to-roll method is preferred from the viewpoint of improving productivity and reducing axial misalignment of each layer. On the other hand, the sheet-to-sheet method is preferred because it is suitable for small-lot, high-mix production and because it allows the selection of a special adhesion method such as the above-mentioned adhesive layer thickness of 100 nm or less. Furthermore, examples of methods for applying the adhesive to the adherend include known methods such as roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet printing.

[0082] [Direct Coating of Each Layer] It is also preferable that there is no adhesive layer between the layers of the laminated optical film of the present invention. When forming a layer, the adhesive layer can be eliminated by directly coating the layer on an adjacent layer that has already been formed. Furthermore, when one or both of the adjacent layers contain a liquid crystal compound, it is preferable that the alignment direction of the liquid crystal compound continuously changes at the interface in order to reduce the refractive index difference in all in-plane directions. For example, a retardation layer containing a liquid crystal compound can be directly coated on a linear polarizer containing a liquid crystal compound and a dichroic material, and the liquid crystal compound in the retardation layer can be continuously aligned at the interface due to the alignment regulating force of the liquid crystal compound in the linear polarizer.

[0083] [Lamination Order of Each Layer] The laminated optical film of the present invention is composed of many layers, but the order of the lamination process is not particularly limited and can be selected arbitrarily. For example, when transferring a functional layer from a film consisting of a temporary support and a functional layer, wrinkles, cracks, etc. during transfer can be prevented by adjusting the lamination order so that the thickness of the transferred film is 10 μm or more. In addition, from the viewpoint of reducing the surface roughness Ra of the laminated optical film, if another layer is laminated on a layer with large surface irregularities, the surface irregularities may be further amplified, so it is preferable to laminate the layers in order from the layer with the smallest surface roughness Ra. In addition, the lamination order can also be selected from the viewpoint of improving the manufacturing yield of the laminated optical film and reducing costs.

[0084] [Applications of the Laminated Optical Film of the Present Invention] The laminated optical film of the present invention can be used as a reflective polarizer incorporated into in-vehicle rearview mirrors, virtual reality display devices, electronic viewfinders, and the like, as described in, for example, Patent Documents 4 and 5. In particular, in virtual reality display devices and electronic viewfinders, etc., having a reciprocating optical system in which light is reflected and reciprocated between a reflective polarizer and a half mirror, the laminated optical film of the present invention is very useful from the viewpoint of improving the clarity of the displayed image. Furthermore, virtual reality display devices and electronic viewfinders, etc., having a reciprocating optical system may have optical films such as an absorptive polarizer and a circular polarizer in addition to the reflective polarizer. However, the clarity of the displayed image can be further improved by using the members used in the laminated optical film of the present invention in optical films other than the above-mentioned reflective polarizer.

[0085] <Optical Article> One embodiment of the optical article of the present invention is a composite lens comprising a lens and the laminated optical film of the present invention. A half mirror may be formed on one side of the lens. The lens may be a convex lens or a concave lens. The convex lens may be a biconvex lens, a plano-convex lens, or a convex meniscus lens. The concave lens may be a biconcave lens, a plano-concave lens, or a concave meniscus lens. Lenses used in virtual reality display devices are preferably convex meniscus lenses or concave meniscus lenses to widen the viewing angle, and more preferably concave meniscus lenses to minimize chromatic aberration. Lens materials that are transparent to visible light, such as glass, crystal, and plastic, can be used. Since birefringence of lenses can cause rainbow unevenness and light leakage, small birefringence is preferable, and zero-birefringence materials are more preferable. The laminated optical film of the present invention used in the optical article of the present invention may be flat or curved, with curved surfaces being preferred to minimize image distortion and aberration.

[0086] <Virtual reality display device> One embodiment of a virtual reality display device includes an image display device that emits at least polarized light and a composite lens that is the optical article of the present invention. In addition, the virtual reality display device may include additional optical components such as a half mirror and a diopter adjustment lens.

[0087] <Image Display Device> The image display device used in the present invention can be a known image display device. Examples include organic electroluminescence display devices, LED (Light Emitting Diode) display devices, micro LED display devices, and other display devices in which self-luminous fine light emitters are arranged on a transparent substrate. These self-luminous display devices typically have a (circular) polarizing plate attached to the display surface to prevent reflection on the display surface. Therefore, the emitted light is polarized. Another example of an image display device is a liquid crystal display device. Liquid crystal display devices also have a polarizing plate on their surface, so the emitted light is polarized. In the following description, organic electroluminescence display devices are also referred to as OLEDs. OLED is an abbreviation for "organic light emitting diode."

[0088] <Molding Method> The laminated optical film of the present invention may be used in a flat form or may be molded into any shape. Here, the laminated optical film will be referred to as an optical film, and the molding method will be described. The molding method for the optical film includes a step of heating the optical film, a step of pressing the optical film against a mold and deforming it to conform to the shape of the mold, and a step of cutting the optical film.

[0089] [Step of Heating Optical Film] Methods for heating the optical film include heating by contacting it with a heated solid, heating by contacting it with a heated liquid, heating by contacting it with a heated gas, heating by irradiating it with infrared rays, and heating by irradiating it with microwaves. However, heating by irradiating it with infrared rays, which allows heating to be performed remotely immediately before molding, is preferred.

[0090] The wavelength of the infrared rays used for heating is preferably 1.0 μm to 30.0 μm, and more preferably 1.5 μm to 5 μm. Examples of IR light sources that can be used include near-infrared lamp heaters with a tungsten filament sealed in a quartz tube and wavelength-controlled heaters with multiple quartz tubes and a mechanism for cooling some of the spaces between the quartz tubes with air. Furthermore, by creating a distribution of infrared radiation on the optical film, the physical properties during molding can be controlled according to the purpose. Methods for creating an intensity distribution include varying the density of IR light sources and placing a filter with a patterned infrared transmittance between the IR light source and the optical film. Examples of filters with a patterned transmittance include glass with metal vapor deposition, filters with an infrared reflection band in a cholesteric liquid crystal layer, filters with an infrared reflection band in a dielectric multilayer film, and infrared-absorbing ink. The temperature of the optical film is controlled by the intensity of infrared radiation, as well as the infrared radiation duration and irradiance. The temperature of the optical film can be monitored using a non-contact radiation thermometer or a thermocouple, and molding can be performed at a target temperature.

[0091] [Step of Pressing the Optical Film Against the Mold and Deforming it to Fit the Mold Shape] The optical film can be pressed against the mold and deformed to fit the mold shape by reducing or pressurizing the molding space. Alternatively, a mold pressing method can be used.

[0092] [Step of Cutting Optical Film] The molded optical film can be cut into any desired shape using a cutter, scissors, a cutting plotter, a laser cutter, or the like.

[0093] <Molding Apparatus> One form of molding apparatus consists of box 1 with an opening facing upward and box 2 with an opening facing downward. To form the molding space, the openings of box 1 and box 2 are aligned directly or via other jigs to form a sealed molding space. A mold (also called an adherend) with the shape to be molded and the film to be molded are placed in the molding space. The film to be molded acts as a partition, dividing the molding space consisting of box 1 and box 2 into two spaces. The mold is placed on the box 1 side, below the film to be molded. Furthermore, the vacuum molding apparatus has multiple heating elements dispersedly arranged to heat the film to be molded. The heating elements may be placed inside the molding space, or they may be placed outside the molding space and heat the film to be molded through a transparent window.

[0094] The features of the present invention will be explained in more detail below with reference to examples. Note that the materials, amounts used, ratios, processing details, processing procedures, etc. shown below can be changed as appropriate without departing from the spirit of the present invention. Furthermore, configurations other than those shown below can also be used without departing from the spirit of the present invention.

[0095] [Preparation of Coating Liquid R-1 for Retardation Layer] The composition shown below was stirred and dissolved in a container kept at 70° C. to prepare Coating Liquid R-1 for Retardation Layer.

[0096] -------------------------------------------------- Coating liquid R-1 for retardation layer -------------------------------------------------- Methyl ethyl ketone 120.9 parts by mass Cyclohexanone 21.3 parts by mass Mixture A of the following rod-like liquid crystal compounds 100.0 parts by mass Photopolymerization initiator B below 1.00 part by mass Surfactant F1 below 0.1 part by mass

[0097] Rod-shaped liquid crystal compound mixture A

[0098]

[0099] In the above mixture, the numerical values ​​are in mass %. R is a group bonded via an oxygen atom. Furthermore, the average molar absorption coefficient of the above rod-shaped liquid crystal compound in the wavelength range of 300 to 400 nm was 140 / mol cm.

[0100] Surfactant F1

[0101]

[0102] Photopolymerization initiator B

[0103]

[0104] [Preparation of Coating Solution R-2 for Retardation Layer] The composition shown below was stirred and dissolved in a container kept at 70°C to prepare Coating Solution R-2 for Retardation Layer having reverse wavelength dispersion.

[0105] -------------------------------- Coating liquid R-2 for retardation layer ------------------------------------------------ - 16.00 parts by mass of polymerizable liquid crystal compound X-1 below - 42.00 parts by mass of specific liquid crystal compound L-1 below - 42.00 parts by mass of specific liquid crystal compound L-2 below - 0.50 parts by mass of polymerization initiator S-1 below - 4.00 parts by mass of acid anhydride K-1 below - 2.00 parts by mass of polymerizable compound B-1 below - 0.20 parts by mass of leveling agent (compound T-1 below) - 230.00 parts by mass of methyl ethyl ketone (solvent) - 70.00 parts by mass of cyclopentanone (solvent) ------------------------------------------------

[0106]

[0107]

[0108]

[0109]

[0110] <Coating Solution PA-1 for Light Interference Layer> The composition shown below was stirred and dissolved in a container kept at 60° C. to prepare Coating Solution PA-1 for light interference layer.

[0111] -------------------------------- Coating liquid PA-1 for optical interference layer -------------------------------- - Methyl isobutyl ketone 3011.0 parts by mass - Mixture A of the above rod-shaped liquid crystal compounds 100.0 parts by mass - Photopolymerization initiator C described below 5.1 parts by mass - Photoacid generator described below 3.0 parts by mass - Hydrophilic polymer described below 2.0 parts by mass - Vertical alignment agent described below 1.9 parts by mass - Viscosity reducer described below 4.2 parts by mass - Material for interlayer photoalignment film described below 8.0 parts by mass - Stabilizer described below 0.2 parts by mass --------------------------------

[0112] Photopolymerization initiator C

[0113]

[0114] Photoacid generator

[0115]

[0116] hydrophilic polymer

[0117]

[0118] Vertical alignment agent

[0119]

[0120] Viscosity reducer

[0121]

[0122] Materials for interlayer photo-alignment films

[0123]

[0124] stabilizers

[0125]

[0126] [Preparation of Retardation Film 1] A 60 μm thick TAC (triacetyl cellulose) film (TG60, manufactured by Fujifilm Corporation) was prepared as a temporary support.

[0127] The above-prepared coating solution for optical interference layer PA-1 was applied to the TAC film using a wire bar coater, and then dried at 80°C for 60 seconds. Thereafter, the film was exposed to light at 78°C in a low-oxygen atmosphere (100 ppm) at an irradiation dose of 300 mJ / cm. ２ The liquid crystal compound was cured by irradiating it with light from a 365 nm ultraviolet LED lamp, and simultaneously cleaving the cleavage group of the material for the interlayer photo-alignment film. The film was then heated at 115°C for 25 seconds to remove the fluorine-containing substituents. This resulted in the formation of an optical interference layer with cinnamoyl groups on the outermost surface and a film thickness of 90 nm, functioning as a positive C plate. The refractive index nI at a wavelength of 550 nm, measured using an interference film thickness meter OPTM (manufactured by Otsuka Electronics, analyzed using the least squares method), was 1.57. The Rth at a wavelength of 550 nm, measured using an Axoscan (manufactured by Axometrics), was -9 nm.

[0128] Next, the illuminance was 7 mW / cm ２ , irradiation amount 7.9mJ / cm ２ The positive C-plate side was irradiated with polarized UV (wavelength 313 nm). The polarized UV with a wavelength of 313 nm was obtained by passing ultraviolet light emitted from a mercury lamp through a bandpass filter having a transmission band at a wavelength of 313 nm and a wire grid polarizer. The retardation layer coating solution R-1 prepared above was applied to the optical interference layer with a wire bar coater, and then dried at 110°C for 72 seconds. Thereafter, the retardation layer was dried at 100°C under a low-oxygen atmosphere (100 ppm or less) with an illuminance of 80 mW / cm. ２ , irradiation amount 500mJ / cm ２ The film was cured by irradiating it with light from a metal halide lamp, thereby obtaining a retardation film consisting of a light interference layer and a retardation layer. At this time, the coating thickness was adjusted so that the film thickness of the retardation layer after curing was 0.86 μm. The retardation of the obtained retardation film 1 at a wavelength of 550 nm was Re = 146 nm and Rth = 73 nm. The retardation was evaluated using an AxoScan OPMF-1 (manufactured by Optoscience).

[0129] [Preparation of Retardation Films 2 to 6 and 8 to 16] Retardation films 2 to 5 and 8 to 16 were prepared by the same method as Retardation Film 1, except that the film thickness of the light interference layer was changed as shown in Table 1 below. Retardation film 6 was prepared by preparing a retardation layer on a rubbed PET film (A4265 manufactured by Toyobo Co., Ltd., film thickness 100 μm) under the same conditions as Retardation Film 1, without providing a light interference layer, thereby preparing a retardation film without a light interference layer.

[0130] [Preparation of Retardation Film 7] Referring to the description of Example 3 in JP 2012-155308 A, a coating solution 1 for a photo-alignment film was prepared and applied to a 60 μm thick TAC (triacetyl cellulose) film (TG60, manufactured by Fujifilm Corporation) using a wire bar. Drying for 60 seconds with hot air at 115°C formed a light interference layer having cinnamoyl groups on the outermost surface and a film thickness of 90 nm, which functioned as a photo-alignment film. The refractive index nI at a wavelength of 550 nm measured using an interference film thickness meter OPTM (manufactured by Otsuka Electronics, analyzed by the least squares method) was 1.55. The Rth at a wavelength of 550 nm measured using an Axoscan (manufactured by Axometrics) was 0 nm.

[0131] Next, the illuminance was 7 mW / cm ２ , irradiation amount 7.9mJ / cm ２ The film was irradiated from the optical interference layer side with polarized UV (wavelength 313 nm). The polarized UV with a wavelength of 313 nm was obtained by passing ultraviolet light emitted from a mercury lamp through a bandpass filter having a transmission band at a wavelength of 313 nm and a wire grid polarizer. The retardation layer coating solution R-2 prepared above was applied onto the optical interference layer with a wire bar coater, and then dried at 110°C for 72 seconds. Thereafter, the film was irradiated with polarized UV light at an illuminance of 80 mW / cm at 100°C in a low-oxygen atmosphere (100 ppm or less). ２ , irradiation amount 500mJ / cm ２The film was cured by irradiating it with light from a metal halide lamp, thereby obtaining a retardation film having a light interference layer and a retardation layer having reverse wavelength dispersion. At this time, the coating thickness was adjusted so that the film thickness of the retardation layer after curing was 2.5 μm. The retardation of the obtained retardation film 7 at a wavelength of 550 nm was Re = 146 nm and Rth = 73 nm. The retardation was evaluated using an AxoScan OPMF-1 (manufactured by Optoscience).

[0132] [Preparation of Retardation Film 17] Retardation film 17 was prepared in the same manner as Retardation Film 1, except that a photo-alignment layer was formed as a light interference layer by the following process and the coating liquid for the retardation layer was changed to R-2.

[0133] <Formation of Photo-Alignment Layer>

[0134] The coating solution PA2 for forming an alignment layer, which will be described later, was continuously applied onto a 60 μm-thick triacetylcellulose (TAC) film (TG60, manufactured by Fujifilm Corporation) using a wire bar. The support on which the coating film was formed was dried with hot air at 140° C. for 120 seconds, and then the coating film was irradiated with polarized ultraviolet light (10 mJ / cm ２ A photo-alignment layer was formed by using an ultra-high pressure mercury lamp. The film thickness was 90 nm. The refractive index nI at a wavelength of 550 nm measured with an interference film thickness meter OPTM (manufactured by Otsuka Electronics, analyzed by the least squares method) was 1.55. The Rth at a wavelength of 550 nm measured with an Axoscan (manufactured by Axometrics) was 0 nm.

[0135] ------------------------------------------------------------------ (Coating liquid PA2 for forming alignment layer) ------------------------------------------------------------------ Polymer M-PA-1 described below: 100.00 parts by mass Acid generator PAG-1 described below: 5.00 parts by mass Acid generator CPI-110TF described below: 0.005 parts by mass Xylene: 3,660.00 parts by mass Methyl isobutyl ketone: 366.00 parts by mass

[0136] Polymer M-PA-1

[0137]

[0138] Acid generator PAG-1

[0139]

[0140] Acid generator CPI-110TF

[0141]

[0142] [Preparation of Retardation Film 18] Retardation film 18 was prepared in the same manner as retardation film 17, except that the retardation of the retardation layer was changed as shown in Table 1 below.

[0143] [Preparation of Retardation Film 19] A hard coat layer having a refractive index of 1.56 and a thickness of 90 nm was applied to form a light interference layer on the retardation layer of Retardation Film 6. The composition of the hard coat layer coating solution and the coating process are shown below.

[0144] ------------------------------------------------------------------ (Coating liquid HC-1 for hard coat layer) ------------------------------------------------------------------ Polymerizable compound 1: 14 parts by mass (10-functional urethane acrylate (UV-1700B, manufactured by Nippon Synthetic Chemical Industry)) Polymerizable compound 2: 6 parts by mass (fluorene compound (Oxol EA0200, manufactured by Osaka Gas Chemicals)) Photopolymerization initiator: 0.5 parts by mass (oxime ester type (Irgacure OXE01, manufactured by BASF Japan)) Methyl ethyl ketone: 800.00 parts by mass ------------------------------------------------------------------

[0145] The hard coat layer coating solution HC-1 prepared above was applied to the retardation layer of the retardation film 6 using a wire bar coater, and then dried at 80°C for 60 seconds. Thereafter, the hard coat layer was exposed to light at an irradiation dose of 300 mJ / cm at 78°C in a low-oxygen atmosphere (100 ppm). ２The polymerizable compound was cured by irradiating it with light from a 365 nm ultraviolet LED lamp. This produced a retardation film 19 having a 90 nm thick optical interference layer made of a hard coat material on the outermost surface. The refractive index nI at a wavelength of 550 nm measured with an interference film thickness meter OPTM (manufactured by Otsuka Electronics, analyzed by the least squares method) was 1.56. The Rth at a wavelength of 550 nm measured with an Axoscan (manufactured by Axometrics) was 0 nm.

[0146] The properties of the prepared retardation films 1 to 19 are shown in the following Table 1. In Table 1, the retardation Re is the retardation Re of the retardation film, the refractive index is the refractive index of the light interference layer, and Rth is the Rth of the light interference layer.

[0147] Table 1. Prepared retardation films 1 to 19

[0148]

[0149] <Preparation of Linear Polarizer> A linear polarizer was prepared by the following procedure.

[0150] (Preparation of Cellulose Acylate Film 1) —Preparation of Core Layer Cellulose Acylate Dope— The following composition was charged into a mixing tank and stirred to dissolve each component, thereby preparing a cellulose acetate solution to be used as the core layer cellulose acylate dope. ----------------------------------- Core Layer Cellulose Acylate Dope --------------------------------------------------- Cellulose acetate having an acetyl substitution degree of 2.88: 100 parts by mass Polyester compound B described in the examples of JP 2015-227955 A: 12 parts by mass Compound F below: 430 parts by mass Methylene chloride (first solvent): 64 parts by mass Methanol (second solvent): 64 parts by mass

[0151] Compound F

[0152]

[0153] -Preparation of Outer Layer Cellulose Acylate Dope- 10 parts by mass of the following matting agent solution was added to 90 parts by mass of the above core layer cellulose acylate dope to prepare a cellulose acetate solution to be used as the outer layer cellulose acylate dope.

[0154] Matting agent solution - Silica particles with an average particle size of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass Methylene chloride (first solvent) 76 parts by mass Methanol (second solvent) 11 parts by mass The above-mentioned cellulose acylate dope for the core layer 1 part by mass

[0155] Preparation of Cellulose Acylate Film 1 The core layer cellulose acylate dope and the outer layer cellulose acylate dope were filtered through a filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm. The core layer cellulose acylate dope and the outer layer cellulose acylate dope on both sides of the core layer were simultaneously cast onto a drum at 20°C through a casting nozzle (band caster). The film was then peeled off while still containing approximately 20% solvent by weight. Both ends of the film in the width direction were fixed with tenter clips, and the film was stretched transversely at a stretch ratio of 1.1 times while being dried. The film was then transported between the rolls of a heat treatment device and further dried to produce an optical film with a thickness of 40 μm, designated as Cellulose Acylate Film 1. The in-plane retardation of the resulting Cellulose Acylate Film 1 was 0 nm.

[0156] <Formation of Photo-Alignment Layer PA1>

[0157] The coating liquid S-PA-1 for forming an alignment layer, which will be described later, was continuously applied onto the cellulose acylate film 1 using a wire bar. The support on which the coating film was formed was dried with hot air at 140°C for 120 seconds, and then the coating film was irradiated with polarized ultraviolet light (10 mJ / cm ２A photo-alignment layer PA1 was formed by irradiating the substrate with light (using an ultra-high pressure mercury lamp). The film thickness was 0.3 μm.

[0158] ------------------------------------------------------------------ (Coating liquid for forming alignment layer S-PA-1) ------------------------------------------------------------------ Polymer M-PA-1 100.00 parts by mass Acid generator PAG-1 5.00 parts by mass Acid generator CPI-110TF 0.005 parts by mass Xylene 1220.00 parts by mass Methyl isobutyl ketone 122.00 parts by mass

[0159] <Formation of Optically Absorbent Anisotropic Layer P1> The following coating solution S-P-1 for forming an optically absorbent anisotropic layer was continuously applied onto the obtained alignment layer PA1 using a wire bar to form a coating layer P1. The coating layer P1 was then heated at 140°C for 30 seconds and cooled to room temperature (23°C). It was then heated at 90°C for 60 seconds and cooled again to room temperature. Thereafter, an LED lamp (center wavelength 365 nm) was used to apply the coating solution S-P-1 to form an optically absorbent anisotropic layer P1. ２ The alignment layer PA1 was irradiated for 2 seconds under the irradiation conditions of 1.6 μm to form an optically absorptive anisotropic layer P1, which was a linear polarizer, on the alignment layer PA1.

[0160] 0.25 parts by mass of dichroic substance D-1 below 0.36 parts by mass of dichroic substance D-2 below 0.59 parts by mass of dichroic substance D-3 below 2.21 parts by mass of polymer liquid crystal compound M-P-1 below 1.36 parts by mass of low molecular weight liquid crystal compound M-1 below 0.200 parts by mass of polymerization initiator IRGACURE OXE-02 (manufactured by BASF) 0.026 parts by mass of surfactant F-3 below Cyclopentanone 46.00 parts by mass Tetrahydrofuran 46.00 parts by mass Benzyl alcohol 3.00 parts by mass ----------------------------------------------------------------------------------

[0161] Dichroic substance D-1

[0162]

[0163] Dichroic substance D-2

[0164]

[0165] Dichroic substance D-3

[0166]

[0167] Polymer liquid crystal compound M-P-1

[0168]

[0169] Low molecular liquid crystal compound M-1

[0170]

[0171] Surfactant F-3

[0172]

[0173] [Preparation of Laminated Optical Film 1] A broadband dielectric multilayer film (3M trademark APF) was used as a linear reflective polarizer. UV adhesive Chemiseal U2084B (manufactured by Chemitech Corporation, refractive index after curing n 1.60) was applied to one surface of the broadband dielectric multilayer film using a wire bar coater to a thickness of 2 μm. The retardation film 1 was then laminated on top of the UV adhesive using a laminator so that the opposite side of the temporary support was in contact with the UV adhesive. After purging with nitrogen in a purge box until the oxygen concentration was 100 ppm or less, the retardation film 1 was cured by irradiating it with ultraviolet light from a high-pressure mercury lamp from the temporary support side. The illuminance was 25 mW / cm ２ , the irradiation dose is 1000 mJ / cm ２ After curing, the temporary support was peeled off. Furthermore, an optically absorbing anisotropic layer P1 was transferred to the surface of the broadband dielectric multilayer film opposite to the retardation film 1 using the same procedure as above. The optically absorbing anisotropic layer P1 side of the finished film was bonded to a 75 μm thick PMMA film using the above-mentioned UV adhesive Chemiseal U2084B. In this way, a laminated optical film 1 consisting of a retardation film 1, a linear reflective polarizer, and a linear polarizer was obtained.

[0174] Regarding the retardation films 2 to 17 and 19, laminated optical films 2 to 17 and 19 were also produced in the same manner.

[0175] [Preparation of Laminated Optical Film 18] A broadband dielectric multilayer film (3M trademark APF) was used as a linear reflective polarizer. UV adhesive Chemiseal U2084B (manufactured by Chemitech Co., Ltd., refractive index after curing n 1.60) was applied to one side of the broadband dielectric multilayer film using a wire bar coater to a thickness of 2 μm. The retardation film 18 was then laminated with a laminator so that the opposite side of the temporary support was in contact with the UV adhesive. At this time, the angle between the reflection axis of the broadband dielectric multilayer film and the slow axis of the retardation film 18 was set to 15 degrees. After nitrogen purging in a purge box until the oxygen concentration was 100 ppm or less, the retardation film 18 was cured by irradiating ultraviolet light from a high-pressure mercury lamp from the temporary support side. The illuminance was 25 mW / cm ２ , the irradiation dose is 1000 mJ / cm ２After curing, the temporary support was peeled off. Subsequently, a 5 μm thick adhesive (refractive index 1.49) was attached to the surface of the retardation film 18 opposite the linear reflective polarizer. The retardation film 17 was then attached thereon so that the side opposite the temporary support was in contact with the adhesive. At this time, the angle between the reflection axis of the broadband dielectric multilayer film and the slow axis of the retardation film 17 was set to 75 degrees. Then, the temporary support was peeled off. Furthermore, the optically absorbing anisotropic layer P1 was transferred to the surface of the broadband dielectric multilayer film opposite the retardation film using the UV adhesive Chemiseal U2084B in the same manner as above. The optically absorbing anisotropic layer P1 side of the finished film was attached to a 75 μm thick PMMA film using the above UV adhesive Chemiseal U2084B. This resulted in a laminated optical film 18 consisting of a retardation film 17 (Re(550)=146 nm), a retardation film 18 (Re(550)=292 nm), a linear reflective polarizer, and a linear polarizer. The laminate obtained by stacking the retardation film 17 (Re(550)=146 nm) and the retardation film 18 (Re(550)=292 nm) at the above angle has the performance of a broadband λ / 4 plate, and therefore a laminated optical film having a broadband λ / 4 plate was obtained.

[0176] [Formation of Half Mirror on Lens] A half mirror was formed by vapor-depositing aluminum on the convex side of the lens (a convex meniscus lens LE1076-A (diameter 2 inches, focal length 100 mm) manufactured by Thorlab Corp. with Optical Film 2 attached to the concave side) so that the reflectance was 40%.

[0177] [Molding Method] The laminated optical film 1 was set in a molding device. The molding space in the molding device consisted of box 1 and box 2, separated by the laminated optical film 1. A convex meniscus lens LE1076-A (diameter 2 inches, focal length 100 mm, radius of curvature on the concave side 65 mm) manufactured by Thorlab, with aluminum vapor deposition on the convex side, was placed in box 1 below the laminated optical film 1, with the concave side facing up, as a mold. A transparent window was installed on the top of box 2 above the laminated optical film 1, and an IR light source for heating the laminated optical film 1 was installed outside this window. A circular patterned infrared reflective filter was placed between the IR light source and the laminated optical film 1, obtained by cutting a cholesteric liquid crystal layer that reflects infrared light with a wavelength of 2.2 μm to 3.0 μm with a reflectance of approximately 50%, into a 1-inch diameter circle. The patterned infrared reflective filter was positioned so that its center was at the center of the mold when viewed from directly above. Next, a vacuum pump was used to evacuate the inside of box 1 and box 2 to a pressure of 0.1 atmospheres or less. Next, as a step of heating the laminated optical film 1, infrared rays were irradiated to heat the laminated optical film 1 until the center reached 99°C and the edges reached 108°C. Since the glass transition temperature Tg of the PMMA film used as the support was 105°C, the aim was to create a state in which the center was less likely to stretch and the edges were more likely to stretch during molding. Next, as a step of pressing the laminated optical film 1 against the mold and deforming it to conform to the shape of the mold, gas was flowed into box 2 from a gas cylinder to pressurize it to 300 kPa, and the laminated optical film 1 was pressure-bonded to the mold. At this time, the laminated optical film 1 was optically adhered to the lens, which was the mold, via an adhesive sheet. Finally, the laminated optical film 1 was cut out by cutting out the portion protruding from the lens, which was the mold, to obtain a composite lens 1 in which the laminated optical film 1 molded into a curved surface was bonded to the lens.

[0178] Laminated optical films 2 to 19 were also molded into curved surfaces using the same procedure.

[0179] [Evaluation of Ghosting] [Fabrication of Virtual Reality Display Device] A virtual reality display device "Huawei VR Glass" manufactured by Huawei, which is a virtual reality display device employing a reciprocating optical system, was disassembled, and all of the composite lenses were removed. Instead, a composite lens 1 to which a laminated optical film 1 was attached was placed so that the laminated optical film was between the composite lens 1 and the eye, thereby fabricating the virtual reality display device of Example 1. At this time, the refractive index nA of the adhesive layer used to attach the laminated optical film 1 to the lens at a wavelength of 550 nm was 1.49, and the average refractive index nL of the retardation layer at a wavelength of 550 nm was 1.63. The square root of the product of these values ​​((nA × nL) １／２ ) was 1.56, and the refractive index of the optical interference layer was 1.57, which indicates that the refractive index of the optical interference layer is a preferable value for imparting anti-reflection properties to the retardation film. In the prepared virtual reality display device, a black and white checkered pattern was displayed on the image display panel, and the ghost visibility was visually evaluated using the following five-point scale. Here, the refractive index of the adhesive layer and the average refractive index of the liquid crystal layer were measured using an interference film thickness meter OPTM (manufactured by Otsuka Electronics, analyzed using the least squares method).

[0180] <Ghost evaluation> A: Not visible at all. B: Slightly visible but not bothersome. C: Weak ghost visible. D: Slightly strong ghost visible. E: Strong ghost visible.

[0181] Furthermore, virtual reality display devices were fabricated using the same procedures using laminated optical films 2 to 6 and 8 to 16 used in Examples 2 to 4, 6 to 10 and Comparative Examples 1 to 6. The refractive index nA of the adhesive layer used when attaching laminated optical films 2 to 6 and 8 to 16 to the lenses was 1.49 at a wavelength of 550 nm, and the average refractive index nL of the retardation layer at a wavelength of 550 nm was 1.63. The square root of the product of these values ​​((nA × nL) １／２ ) is 1.56, and the refractive index of the light interference layer is 1.57, which indicates that the refractive index of the light interference layer is a preferable value for imparting antireflection properties to the retardation film.

[0182] Furthermore, a virtual reality display device was fabricated in the same manner using the laminated optical film 7 used in Example 5. The refractive index nA of the adhesive layer used when attaching the laminated optical film 7 to the lens at a wavelength of 550 nm was 1.49, and the average refractive index nL of the retardation layer at a wavelength of 550 nm was 1.58. The square root of the product of these values ​​((nA × nL) １／２ ) is 1.53, and the refractive index of the light interference layer is 1.55, which indicates that the refractive index of the light interference layer is a preferable value for imparting antireflection properties to the retardation film.

[0183] Furthermore, a virtual reality display device was fabricated in the same manner using the laminated optical films 17 and 18 used in Examples 11 and 12. The refractive index nA of the adhesive layer used to attach the laminated optical films 17 and 18 to the lens at a wavelength of 550 nm was 1.49, and the average refractive index nL of the retardation layer at a wavelength of 550 nm was 1.58. The square root of the product of these values ​​((nA × nL) １／２ ) is 1.53, and the refractive index of the light interference layer is 1.55, which indicates that the refractive index of the light interference layer is a preferable value for imparting antireflection properties to the retardation film.

[0184] Furthermore, a virtual reality display device was fabricated in the same manner using the laminated optical film 19 used in Example 13. The refractive index nA of the adhesive layer used to attach the laminated optical film 19 to the lens at a wavelength of 550 nm was 1.49, and the average refractive index nL of the retardation layer at a wavelength of 550 nm was 1.63. The square root of the product of these values ​​((nA × nL) １／２ ) is 1.56, and since the refractive index of the light interference layer is 1.56, it is understood that the refractive index of the light interference layer is a preferable value for imparting antireflection properties to the retardation film.

[0185] The types of retardation films and laminated optical films used in each of the examples and comparative examples are shown in Table 2. Table 2 also shows the evaluation results of their ghost visibility.

[0186] As a result, in the virtual reality display devices of Comparative Examples 1 to 6, the light from the white display area was partially visible as a strong ghost in the black display area of ​​the checkered pattern. On the other hand, it was confirmed that the ghost was improved in the virtual reality display devices of Examples 1 to 13, which used a retardation film with a light interference layer that met the specified conditions. Furthermore, when the film thickness of the light interference layer was 90 nm, (nA x nL) １／２ In Example 13, in which the difference in refractive index between the optical interference layer and the optical film is 0.00, it was confirmed that the ghost was improved to a level where it was slightly visible but not noticeable.

[0187] Table 2. Retardation films used in Examples and Comparative Examples and ghost evaluation results

[0188]

[0189] 10-11 Retardation film 21 Retardation layer 22 Optical interference layer 23 Adhesive layer 100 Laminated optical film 101 Adhesive layer 102 Linear reflective polarizer 103 Adhesive layer 104 Linear polarizer 300 Half mirror 400 Circular polarizer 500 Image display panel 600 Lens 1000 Light rays forming a virtual image 2000 Light rays forming a ghost

Claims

1. A retardation film comprising an optical interference layer and a retardation layer disposed adjacent to each other in this order, wherein the optical interference layer has a thickness of 60 nm to 110 nm, or 230 nm to 330 nm.

2. 2. The retardation film according to claim 1, wherein the refractive index in an in-plane direction of the optical interference layer is 1.50 to 1.

70.

3. 2. The retardation film according to claim 1, wherein the refractive index of the optical interference layer in an in-plane direction is 1.53 to 1.

59.

4. Further comprising an adhesive layer, A retardation film in which the adhesive layer, the optical interference layer, and the retardation layer are arranged adjacent to each other in this order, When the refractive index of the adhesive layer is nA and the average refractive index of the retardation layer is nL, the refractive index nI in the in-plane direction of the optical interference layer is (nA × nL) １／２ −0.03≦nI≦(nA×nL) １／２ The retardation film according to claim 1 , wherein the retardation film has a refractive index of +0.

03.

5. The retardation film according to claim 1 , wherein the optical interference layer is a photo-alignment film.

6. A retardation film as described in claim 5, wherein the film thickness of the optical interference layer is 60 nm to 95 nm, or 230 to 330 nm.

7. A retardation film as described in claim 5, wherein the film thickness of the optical interference layer is 60 nm to 95 nm.

8. A retardation film as described in claim 5, wherein the film thickness of the optical interference layer is 230 nm to 330 nm.

9. The retardation film according to claim 1 , wherein the optical interference layer is a C plate.

10. The retardation film according to claim 9 , wherein a compound having a cinnamoyl group is present between the C plate and the retardation layer.

11. The retardation film according to claim 9, wherein the optical interference layer has a thickness of 60 nm to 95 nm.

12. The retardation film according to claim 1 , wherein the optical interference layer is a hard coat layer.

13. A laminated optical film having at least a retardation film and a linear reflective polarizer, The retardation film is the retardation film according to any one of claims 1 to 4, and the linear reflective polarizer is disposed on the retardation layer on the opposite side to the optical interference layer.

14. The laminated optical film of claim 13 further comprising a linear polarizer.

15. The laminated optical film according to claim 14 , wherein the linear polarizer comprises a light-absorbing anisotropic layer containing at least a liquid crystal compound and a dichroic material.

16. The laminated optical film of claim 13 , further comprising a positive C-plate.

17. The laminated optical film of claim 13 further comprising an anti-reflection layer.

18. The laminated optical film according to claim 17 , wherein the antireflection layer is a moth-eye film or an AR film.

19. The laminated optical film according to claim 13 , comprising a resin substrate having a peak temperature of loss tangent tanδ of 170° C. or less.

20. An optical article comprising the laminated optical film according to claim 13 and a lens.

21. A virtual reality display device comprising the optical article of claim 20.