Optical element, image display device, virtual reality display device, electronic viewfinder, and method for manufacturing polarizer

Abstract

To provide an optical element that excels in effect of suppressing ghosts when an absorption type polarizer having a curved section is applied to an image display device using a reciprocal optical system, and also provide an image display device, a virtual reality display device, an electronic finder, and a polarizer manufacturing method.SOLUTION: An optical element includes an absorption type polarizer A having a curved section and an absorption type polarizer B. When a position closest to the polarizer B side of the polarizer A on the surface of the polarizer B side is regarded as a position X, a surface position on the polarizer A side of the polarizer B that is closest to the position X is regarded as a position Y, and a straight line L passing through the positions X and Y is drawn, a position Z that satisfies a specific requirement exists on the straight line L and at a position opposite the position X when the position X is observed from the position Y.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical element, an image display device, a virtual reality display device, an electronic viewfinder, and a method for manufacturing a polarizer. [Background technology]

[0002] Absorptive polarizers are widely used in image display devices such as liquid crystal display devices and organic EL display devices, and in most cases, the absorption axes of these polarizers are generally aligned (linear) in the plane. Meanwhile, in recent years, in order to make the display units of image display devices such as virtual reality display devices and electronic viewfinders smaller and thinner, image display devices using reciprocating optical systems have been proposed, such as that described in Patent Document 1. In these virtual image display devices, an absorption-type polarizer is used on the viewing side to suppress undesirable images such as ghosts (hereinafter simply referred to as "ghosts") that are generated by stray light, and in this case, it is desirable that the polarizer also has a curved surface to match the shape of the lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-120679 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the inventor's investigations, it has been found that in an image display device using a reciprocating optical system, even if an absorption-type polarizer having a curved surface is installed on the viewing side, stray light cannot be sufficiently suppressed, and ghosts may be displayed.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an optical element that exhibits an excellent effect of suppressing ghosting when an absorption-type polarizer having a curved surface is applied to an image display device using a reciprocating optical system. Another object of the present invention is to provide an image display device, a virtual reality display device, an electronic viewfinder, and a method for manufacturing a polarizer. [Means for solving the problem]

[0006] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by the following configuration.

[0007] [1] An optical element including an absorptive polarizer A having a curved portion and an absorptive polarizer B, wherein when the position on the surface of polarizer A facing polarizer B that is closest to polarizer B is defined as position X, and the position on the surface of polarizer B facing polarizer A that is closest to position X is defined as position Y, and a line L is drawn that passes through positions X and Y, a position Z that satisfies certain requirements exists on line L at a position on the far side of position X when position X is observed from position Y. [2] The optical element according to [1], wherein the polarizer A has regions whose absorption axes are oriented in different directions. [3] The optical element according to [1] or [2], wherein the polarizer A has an optically absorptive anisotropic layer containing a liquid crystal compound and a dichroic substance. [4] The optical element according to [3], wherein the polarizer A further has a photo-alignment film. [5] An image display device comprising the optical element according to any one of [1] to [4] and an image display element. [6] The image display device according to [5], further comprising: a reflective linear polarizer, a first λ / 4 plate, a half mirror, and a second λ / 4 plate, in this order from the polarizer A side, between the polarizer A and the polarizer B; wherein the direction of the absorption axis of the polarizer A at the position X is parallel to the direction of the reflection axis of the reflective linear polarizer at the intersection of the line L and the reflective linear polarizer, when observed from the direction along which the line L extends; and the direction of the absorption axis of the polarizer A at the intersection of the virtual lines L1 to L4 and the polarizer A is parallel to the direction of the reflection axis of the reflective linear polarizer at the intersection of the virtual lines L1 to L4 and the reflective linear polarizer, when observed from the direction along which the virtual lines L1 to L4 extend. [7] The image display device according to [6], wherein the angle formed by the direction of the absorption axis of the polarizer A at position X and the direction of the slow axis of the first λ / 4 plate at the intersection of the line L and the first λ / 4 plate is 45±10° when observed from the direction in which the line L extends, and the angle formed by the direction of the absorption axis of the polarizer A at the intersection of the virtual lines L1 to L4 and the polarizer A and the direction of the slow axis of the first λ / 4 plate at the intersection of the virtual lines L1 to L4 and the first λ / 4 plate is 45±10° when observed from the direction in which the virtual lines L1 to L4 extend. [8] The image display device according to [6] or [7], wherein the direction of the slow axis of the first λ / 4 plate at the intersection of the straight line L and the first λ / 4 plate is perpendicular to the direction of the slow axis of the second λ / 4 plate at the intersection of the straight line L and the second λ / 4 plate when observed from the direction in which the straight line L extends, and the direction of the slow axis of the first λ / 4 plate at the intersection of the virtual lines L1 to L4 and the first λ / 4 plate is perpendicular to the direction of the slow axis of the second λ / 4 plate at the intersection of the virtual lines L1 to L4 and the second λ / 4 plate when observed from the direction in which the virtual lines L1 to L4 extend. [9] The image display device according to [5], further comprising: a first λ / 4 plate, a reflective circular polarizer, a half mirror, and a second λ / 4 plate, in this order from the polarizer A side, between the polarizer A and the polarizer B; an angle formed by the direction of the absorption axis of the polarizer A at position X and the direction of the slow axis of the first λ / 4 plate at the intersection of the line L and the first λ / 4 plate is 45±10° when observed from the direction in which the line L extends; and an angle formed by the direction of the absorption axis of the polarizer A at the intersection of the virtual lines L1 to L4 and the polarizer A and the direction of the slow axis of the first λ / 4 plate at the intersection of the virtual lines L1 to L4 and the first λ / 4 plate is 45±10° when observed from the direction in which the virtual lines L1 to L4 extend.

[10] The image display device according to [9], wherein the reflective circular polarizer has a cholesteric liquid crystal layer.

[11] The image display device according to any one of [5] to

[10] , wherein the polarizer B is laminated on the image display element.

[12] A virtual reality display device comprising the image display device according to any one of [5] to

[11] .

[13] An electronic viewfinder equipped with the image display device according to any one of [5] to

[11] .

[14] A method for manufacturing an absorption polarizer having a plurality of regions whose absorption axis directions are different from each other and a curved portion, the method comprising the step of spray-coating a composition containing a liquid crystalline compound and a dichroic substance onto the surface of an alignment film, wherein the alignment film has the curved portion and the plurality of regions whose alignment regulating force directions are different from each other.

[15] The method for producing a polarizer according to

[14] , further comprising the step of forming an alignment film by forming a layer of a composition for forming a photoalignment film containing a photoalignment agent on the surface of a resin substrate and then irradiating the layer with linearly polarized ultraviolet light through a lens to align the photoalignment agent. [Effects of the Invention]

[0008] According to the present invention, an optical element that exhibits excellent ghost suppression effects when an absorption-type polarizer having a curved surface is applied to a virtual image display device using a reciprocating optical system can be provided. Also, according to the present invention, an image display device, a virtual reality display device, an electronic viewfinder, and a method for manufacturing a polarizer can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an example of the configuration of an optical element according to the present invention. [Figure 2] FIG. 1 is a schematic diagram showing an example of the configuration of an image display device using a conventional reciprocating optical system. [Figure 3] FIG. 2 is a schematic diagram showing the direction of the absorption axis of absorptive polarizer A. [Figure 4] 1 is a schematic diagram illustrating a configuration of an image display device according to a first embodiment of the present invention. [Figure 5] FIG. 10 is a schematic diagram showing the configuration of an image display device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below with reference to the drawings. The following description of the components 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.

[0011] 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°.

[0012] In this specification, the term "absorption axis" refers to the direction in which absorbance is maximized in the plane. The term "reflection axis" refers to the direction in which reflectance is maximized in the plane. The term "slow axis" refers to the direction in which refractive index is maximized in the plane. In this specification, the term "local absorption axis" does not refer to the average absorption axis orientation across the entire region of the film, but rather refers to the local absorption axis orientation at a point of interest.

[0013] [Optical elements] The optical element according to the present invention (hereinafter also referred to as "the optical element") is an optical element that includes an absorptive polarizer A having a curved surface portion and an absorptive polarizer B, and on a line L connecting a specific position X of polarizer A and a specific position Y of polarizer B, there is a position Z that satisfies the requirements described below.

[0014] FIG. 1 shows an example of the configuration of an optical element according to the present invention. 1 includes a polarizer A100 and a polarizer B400. The polarizer A100 is an absorptive polarizer having a curved surface, and the polarizer B400 is a flat absorptive polarizer. As shown in FIG. 1, in optical element 10, when position X is the position on the surface of polarizer A facing polarizer B that is closest to polarizer B, and position Y is the position on the surface of polarizer B facing polarizer B that is closest to position X, and a line L is drawn passing through positions X and Y, there exists position Z on line L, at a position on the far side of position X when position X is observed from position Y, that satisfies the following requirements (hereinafter also referred to as "specific requirements").

[0015] (Specific requirements) (a) There are imaginary lines L1, L2, L3, and L4 that pass through position Z and form an angle of 30° with line L. (b) The angle between the straight line Lp1 orthogonally projected onto the polarizer B of the virtual line L1 and the straight line Lp2 orthogonally projected onto the polarizer B of the virtual line L2 is 90°, the angle between the straight line Lp2 and the straight line Lp3 orthogonally projected onto the polarizer B of the virtual line L3 is 90°, the angle between the straight line Lp3 and the straight line Lp4 orthogonally projected onto the polarizer B of the virtual line L4 is 90°, and the angle between the straight line Lp4 and the straight line Lp1 is 90°. (c) The angle between the line Lp1 and the absorption axis of the polarizer B is 45°. (d) When observed from the direction in which the straight line L extends, the direction of the absorption axis of polarizer A at position X and the direction of the absorption axis of polarizer B at position Y are perpendicular to each other. (e) When observed from the direction in which the virtual line L1 extends, the direction of the absorption axis of polarizer A at the intersection of virtual line L1 and polarizer A and the direction of the absorption axis of polarizer B at the intersection of virtual line L1 and polarizer B are perpendicular to each other. (f) When observed from the direction in which the virtual line L2 extends, the direction of the absorption axis of polarizer A at the intersection of virtual line L2 and polarizer A and the direction of the absorption axis of polarizer B at the intersection of virtual line L2 and polarizer B are perpendicular to each other. (g) When observed from the direction in which the virtual line L3 extends, the direction of the absorption axis of polarizer A at the intersection of virtual line L3 and polarizer A and the direction of the absorption axis of polarizer B at the intersection of virtual line L3 and polarizer B are perpendicular to each other. (h) When observed from the direction in which virtual line L4 extends, the direction of the absorption axis of polarizer A at the intersection of virtual line L4 and polarizer A and the direction of the absorption axis of polarizer B at the intersection of virtual line L4 and polarizer B are perpendicular to each other.

[0016] As a result of extensive research into the above-mentioned problems, the present inventors have found that in an optical element having an absorptive polarizer A with a curved surface and an absorptive polarizer B, by adjusting the configurations of polarizers A and B so that a position Z that satisfies the above-mentioned specific requirement exists, and in particular by specifying the local orientation of the absorption axis of polarizer A, the effect of suppressing ghosts can be improved even in image display devices that use absorptive polarizers with curved portions.

[0017] The present inventors have considered the reason why ghosts cannot be sufficiently suppressed when an absorption-type polarizer having a curved surface portion is installed on the viewing side in an image display device using a conventional reciprocating optical system as follows. The above-mentioned causes and the effects of the optical element according to the present invention will be explained below. Fig. 2 is a schematic diagram showing an example of the configuration of an image display device using a conventional reciprocating optical system. A conventional image display device 30 shown in FIG. 2 includes, in order from the observer's viewpoint O (viewing side), at least a curved absorptive polarizer 31, a reflective polarizer 32, a half mirror 33, an absorptive polarizer 34, and an image display element 35. The image display device 30 also includes a retardation plate, such as a λ / 4 plate (not shown). When the image display device 30 is in use, as shown in FIG. 2, a light ray V emitted from the image display element 35 is reflected by the reflective polarizer 32 and the half mirror 33, travels back and forth within the optical system, passes through the reflective polarizer 32 and the absorptive polarizer 34, and then emerges from a lens (not shown) on the viewing side. The round-trip travel of the light ray V in this manner extends the optical path, contributing to the miniaturization and slimming of the optical system. Thus, conventional round-trip optical systems are designed to appropriately reflect and polarize the light ray V.

[0018] However, the inventors' investigations have revealed that most of the ghosts observed in image display devices using a round-trip optical system are not caused by light ray V that travels back and forth within the optical system, but by light ray S (see FIG. 2 ) that passes through the reflective polarizer 32 without traveling back and forth and reaches the observer's viewpoint O directly. In particular, when the polarization degree of the reflective polarizer 32 is insufficient, there is a tendency for light ray S to be transmitted without being reflected by the reflective polarizer 32. The transmission of light ray S can be suppressed by the absorbing polarizer 31 arranged on the viewing side. However, because the absorbing polarizer 31 has a curved surface, the local absorption axis of the absorbing polarizer 31 at the intersection of the line connecting the viewpoint O and the absorbing polarizer 34 with the absorbing polarizer 31 is not strictly orthogonal to the local absorption axis of the absorbing polarizer 34 at the intersection of the absorbing polarizer 34 and the line. This may result in insufficient blocking of light ray S, and thus insufficient suppression of ghosts. Furthermore, it has been found that when an image is viewed from the observer's viewpoint O closer to the periphery of the image display element 35, that is, when the angle between the line of sight (=light ray S) when viewing the image from viewpoint O and the normal to the display surface of the image display element 35 is larger, the occurrence of ghosts due to light ray S becomes more noticeable.

[0019] In contrast, in optical element 10 according to the present invention, polarizer A100 and polarizer B400 are configured so that, at a position spaced apart from polarizer A100, there exists position Z where line L and virtual lines L1-L4 intersect, such that the angle between the absorption axis of polarizer A100 and the absorption axis of polarizer B400 is 90° at each intersection point on the line, as shown in Fig. 1. Therefore, when optical element 10 is used in an image display device, by observing from position Z, it is possible to suppress light ray S that exits without making a round trip inside the optical system in absorptive polarizer A100 having a curved surface, thereby suppressing the occurrence of ghosts in the displayed image being observed. In particular, the above-described excellent effect is more pronounced with respect to suppression of ghosts in the image display region closer to the periphery of the image display element.

[0020] [How to determine position Z] The position Z in the optical element can be identified, for example, by the following method. First, in the optical element, position X is found on the surface of polarizer A facing the polarizer B, which is closest to position X. Next, position Y is found on the surface of polarizer B facing the polarizer A, which is closest to position X. Based on the confirmed positions X and Y, a line L passing through positions X and Y is determined. In other words, the perpendicular line drawn from position X to polarizer B is line L, and the intersection of this perpendicular line with the surface of polarizer B facing the polarizer A is position Y. In FIG. 1, position Y is located at the center of polarizer B. Next, assume that there is a point W on the line L that is located on the other side of position X when observing position X from position Y. Then, find imaginary lines Lw1, Lw2, Lw3, and Lw4 that pass through point W, make an angle of 30° with line L, and satisfy the following requirements: Requirements: The angle between line Lp1, which is the orthogonal projection of virtual line Lw1 onto polarizer B, and line Lp2, which is the orthogonal projection of virtual line Lw2 onto polarizer B, is 90°; the angle between line Lp2 and line Lp3, which is the orthogonal projection of virtual line Lw3 onto polarizer B, is 90°; the angle between line Lp3 and line Lp4, which is the orthogonal projection of virtual line Lw4 onto polarizer B, is 90°; the angle between line Lp4 and line Lp1 is 90°; and the angle between line Lp1 and the absorption axis of polarizer B is 45°.

[0021] Next, using an AxoScan OPMF-1 (manufactured by OptoScience), the absorption axis of polarizer A at the intersection of the virtual line Lw1 and polarizer A, and the absorption axis of polarizer B at the intersection of the virtual line Lw1 and polarizer B are measured. When measuring the absorption axis of polarizer A, polarizer B is removed from the optical elements, and polarizer A is fixed so that the direction of the AxoScan measurement beam coincides with the virtual line Lw1 and the positional relationship between the virtual line Lw1 and polarizer A is not changed, and the absorption axis is measured. Similarly, when measuring the absorption axis of polarizer B, polarizer A is removed from the optical elements, and polarizer B is fixed so that the direction of the AxoScan measurement beam coincides with the virtual line Lw1 and the positional relationship between the virtual line Lw1 and polarizer B is not changed, and the absorption axis is measured. By comparing the two measured values, it is determined whether the angle between the absorption axis of polarizer A at the intersection of virtual line Lw1 and polarizer A and the absorption axis of polarizer B at the intersection of virtual line Lw1 and polarizer B is 90° when observed from the direction in which virtual line Lw1 extends. Similar measurements and determinations are also carried out for the straight line L and the imaginary lines Lw2 to Lw4.

[0022] While moving the position of point W on the straight line L, setting of virtual lines Lw1 to Lw4 and measurement of the absorption axes of polarizers A and B at the intersections with each virtual line are repeated according to the above method. As a result, for all of the straight line L and virtual lines Lw1 to Lw4, if the angle between the absorption axis of polarizer A and the absorption axis of polarizer B when observed from the above observation direction is 90°, point W is identified as position Z. Note that the virtual lines Lw1 to Lw4 passing through point W (position Z) at this time correspond to the virtual lines L1 to L4 defined in the above specific requirement, respectively. With regard to this optical element, the virtual lines L1, L2, L3, and L4 are all different, and the straight lines Lp1, Lp2, Lp3, and Lp4 are all different.

[0023] The optical element will be described in detail below.

[0024] The absorptive polarizer A having a curved surface portion and the absorptive polarizer B that this optical element comprises are not particularly limited, as long as they are configured so that there is a position Z at which both polarizers A and B satisfy specific requirements. In this specification, the expression "having a curved surface portion" of a polarizer means that at least a part of the polarizer is formed as a curved surface. The polarizer A is preferably formed of a curved surface as a whole. The polarizer A preferably has a three-dimensional curved surface, and is preferably formed of a three-dimensional curved surface as a whole. The three-dimensional curved surface refers to a curved surface that is not developable. The developable surface refers to a curved surface that can be developed into a plane without stretching, that is, a curved surface that can be created by bending or cutting a plane. Furthermore, polarizer A preferably has a surface of rotation in which the surface facing polarizer B is convex and the surface opposite to polarizer B is concave, and more preferably has a curved surface with a constant radius of curvature. Here, "constant radius of curvature" means that the difference between the maximum and minimum radii of curvature on the surface of an optical component such as polarizer A is within 5% of the minimum radius of curvature. When the polarizer A has a curved surface with a constant radius of curvature, the radius of curvature can be appropriately selected depending on the size and application of the optical element and image display device, but is preferably 20 to 1000 mm, more preferably 30 to 200 mm. The polarizer B may be flat or may have a curved portion. When the polarizer B has a curved portion, it may be the same as the polarizer A described above, including preferred aspects.

[0025] Assuming that a straight line Lz connects position Z and polarizer B, the angle between the local absorption axis of polarizer A at the intersection with line Lz and the local absorption axis of polarizer B at the intersection with line Lz is 90° when observed from the direction of extension of line Lz. By satisfying this relationship over the entire region of polarizer B, ghosts that occur in displayed images can be more effectively suppressed in an image display device manufactured using this optical element. Whether or not the optical element satisfies the above relationship can be measured in accordance with the method for specifying the position Z described above.

[0026] The polarizer A and the polarizer B will be described in detail below.

[0027] [Polarizer A] The polarizer A is an absorptive polarizer. As the polarizer A, a known absorptive polarizer having at least a light-absorptive anisotropic layer containing a dichroic material can be used. The light absorption anisotropic layer may be, for example, a layer containing a matrix compound and a dichroic substance, and is preferably a layer containing a liquid crystal compound and a dichroic substance. The degree of orientation of the dichroic material in the light absorption anisotropic layer is preferably 0.95 or more, more preferably 0.97 or more. The higher the degree of orientation, the more effectively ghosting can be suppressed. The upper limit of the degree of orientation is not particularly limited, and may be 0.99 or less, preferably 0.98 or less.

[0028] The polarizer A preferably has a plurality of regions whose absorption axes are different from one another. That is, it is preferable that the polarizer A has two or more regions in its plane where the local absorption axes are not parallel to one another. Fig. 3 shows an example of the absorption axis orientation distribution when polarizer A has multiple regions with different absorption axis directions. Fig. 3 is a schematic diagram showing the distribution of orthogonal projections of the local absorption axes of polarizer A onto a plane (polarizer B), and in Fig. 3, each "AA" indicates the direction of the orthogonal projection of the absorption axis. As shown in Fig. 3, when polarizer A has multiple regions with different orthogonal projection directions AA, it is clear that polarizer A also has multiple regions with different absorption axis directions.

[0029] The absorption axis of polarizer A can be measured using AxoScan OPMF-1, as described above (method of identifying position Z). The polarizer A having the absorption axis oriented as described above can be formed, for example, by the method described later in <<Method for forming an optically absorptive anisotropic layer>>. The absorption axis of polarizer A is not limited to the above embodiment as long as it has a position Z that satisfies the specific requirement. For example, a combination of polarizer A whose absorption axes are entirely parallel and polarizer B having multiple regions whose absorption axes are different from one another may provide a position Z that satisfies the specific requirement.

[0030] <<Resin substrate>> The polarizer A may include a resin substrate. When the polarizer A is molded into a curved surface, the resin substrate preferably has a tan δ peak temperature of 170° C. or less. From the viewpoint of enabling molding at a lower temperature, the tan δ peak temperature is preferably 150° C. or less, and more preferably 130° C. or less.

[0031] 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 conditioned in advance 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 calculated as the value. Equipment: IT Measurement and Control Co., Ltd. DVA-200 Sample: 5 mm, length 50 mm (gap 20 mm) Measurement conditions: tension mode Measurement temperature: -150℃~220℃ Temperature rise condition: 5℃ / min Frequency: 1Hz In optical applications, stretched resin substrates are often used, and the stretching process often increases the peak temperature of tan δ. For example, the peak temperature of tan δ for a TAC (triacetyl cellulose) substrate (TG40, manufactured by Fujifilm Corporation) is 180°C or higher.

[0032] The resin substrate is not particularly limited, and substrates made of various optical resins can be used, but a resin substrate having a peak temperature of tan δ of 170°C or less is preferred. Examples of resins constituting such a resin substrate include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate; acrylic resins such as polymethacrylates and polyacrylates; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; and polyphenylene sulfide and polyphenylene oxide. Among these, cyclic olefin-based resins, polyethylene terephthalate, and acrylic resins are preferred because of their easy commercial availability and excellent transparency, and cyclic olefin-based resins and polymethacrylates are more preferred.

[0033] Commercially available resin substrates include Technoloy S001G, Technoloy S014G, Technoloy S000, Technoloy C001, and Technoloy C000 (Sumika Acrylic Sales Co., Ltd.), Lumirror U Type, Lumirror FX10, and Lumirror SF20 (Toray Industries, Inc.), HK-53A (Higashiyama Film Co., Ltd.), Teflex FT3 (Teijin DuPont Films Japan Co., Ltd.), S-Cina and SCA40 (Sekisui Chemical Co., Ltd.), Zeonor Film (Optes Co., Ltd.), and Arton Film (JSR Corporation).

[0034] The thickness of the resin substrate is not particularly limited, but is preferably 5 to 300 μm, more preferably 5 to 100 μm, and even more preferably 5 to 30 μm.

[0035] <<Light-absorbing anisotropic layer>> As described above, the light absorption anisotropic layer preferably contains a liquid crystal compound and a dichroic substance. Such an optically absorptive anisotropic layer can be formed using a composition containing a liquid crystal compound and a dichroic substance (hereinafter also referred to as "optically absorptive anisotropic layer-forming composition"). In order to suppress a decrease in polarization degree upon heating, it is preferable that the liquid crystal compound and / or dichroic substance contained in the composition for forming an optically absorptive anisotropic layer have a radical polymerizable group. The molar content of the radical polymerizable group relative to the solids weight of the composition for forming an optically absorptive anisotropic layer is preferably 0.6 mmol / g or more, more preferably 1.0 mmol / g or more, and even more preferably 1.5 mmol / g or more. There is no particular upper limit, but it is preferably 5 mmol / g or less.

[0036] <Liquid crystal compounds> The composition for forming the optically absorptive anisotropic layer contains a liquid crystalline compound. The liquid crystal compound is preferably a liquid crystal compound that does not exhibit dichroism in the visible region. The liquid crystal compound can be either a low-molecular-weight liquid crystal compound or a high-molecular-weight 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. "High-molecular-weight liquid crystal compound" refers to a liquid crystal compound that has a repeating unit in its chemical structure. Examples of low-molecular-weight liquid crystal compounds include those described in paragraphs

[0027] to

[0034] of JP-A No. 2013-228706. Among these, low-molecular-weight liquid crystal compounds exhibiting smectic properties are preferred. Examples of the polymeric liquid crystalline compound include the thermotropic liquid crystalline polymers described in JP 2011-237513 A. The polymeric liquid crystalline compound preferably has a crosslinkable group (e.g., an acryloyl group or a methacryloyl group) at its terminal. The liquid crystal compounds may be used alone or in combination of two or more. 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 crystalline compound is preferably 25 to 2000 parts by mass, more preferably 33 to 1000 parts by mass, and even more preferably 50 to 500 parts by mass, relative to 100 parts by mass of the content of the dichroic substance in the composition for forming an optically absorptive anisotropic layer. When the content of the liquid crystalline compound is within the above range, the degree of orientation of the polarizer is further improved.

[0037] The liquid crystalline compound is preferably a polymeric liquid crystalline compound, because this results in a higher degree of orientation of the resulting light absorption anisotropic layer, and more preferably a polymeric liquid crystalline compound containing a repeating unit represented by the following formula (1) (hereinafter also abbreviated as "repeating unit (1)").

[0038] [ka]

[0039] In the above formula (1), P1 represents the main chain of the repeating unit, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesogenic group, and T1 represents a terminal group.

[0040] Examples of the main chain of the repeating unit represented by P1 include groups represented by the following formulae (P1-A) to (P1-D). Among these, the group represented by the following formula (P1-A) is preferred from the viewpoints of the variety of monomers that serve as raw materials and ease of handling.

[0041] [ka]

[0042] In formulas (P1-A) to (P1-D), "*" represents the bonding position with L1 in formula (1). 1 represents a hydrogen atom or a methyl group. 2 represents an alkyl group. The group represented by formula (P1-A) is preferably one unit of a partial structure of a poly(meth)acrylic acid ester obtained by polymerization of a (meth)acrylic acid ester, because this results in a higher degree of orientation of the resulting optically absorptive anisotropic layer. The group represented by formula (P1-B) is preferably an ethylene glycol unit in polyethylene glycol obtained by polymerizing ethylene glycol, because this results in a higher degree of orientation in the resulting optically absorptive anisotropic layer. The group represented by formula (P1-C) is preferably a propylene glycol unit obtained by polymerizing propylene glycol, because this leads to a higher degree of orientation in the resulting optically absorptive anisotropic layer. The group represented by formula (P1-D) is preferably a siloxane unit of polysiloxane obtained by condensation polymerization of silanol, because this leads to a higher degree of orientation in the resulting optically absorptive anisotropic layer.

[0043] L1 is a single bond or a divalent linking group. Examples of the divalent linking group represented by L1 include -C(O)O-, -OC(O)-, -O-, -S-, and -C(O)NR 3 -, -NR 3 C(O)-, -SO2-, and -NR 3 R 4 In the formula, R 3 and R 4 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. When P1 is a group represented by formula (P1-A), L1 is preferably a group represented by -C(O)O- because the degree of orientation of the resulting optically absorptive anisotropic layer is higher. When P1 is a group represented by any of the formulae (P1-B) to (P1-D), L1 is preferably a single bond because the degree of orientation of the resulting optically absorptive anisotropic layer is higher.

[0044] The spacer group represented by SP1 preferably contains at least one structure selected from the group consisting of an oxyethylene structure, an oxypropylene structure, a polysiloxane structure, and a fluorinated alkylene structure, because this facilitates the development of liquid crystallinity and because of the availability of raw materials. Here, the oxyethylene structure represented by SP1 is *-(CH2-CH2O) n1 A group represented by -* is preferred. In the formula, n1 represents an integer of 1 to 20, and * represents the bonding position with L1 or M1 in the above formula (1). n1 is preferably an integer of 2 to 10, more preferably an integer of 2 to 4, and most preferably 3, because this increases the degree of orientation of the resulting light absorption anisotropic layer. The oxypropylene structure represented by SP1 is *-(CH(CH3)-CHO) because it results in a higher degree of orientation of the resulting optically absorbing anisotropic layer. n2 A group represented by -* is preferred, where n2 represents an integer of 1 to 3, and * represents the bonding position to L1 or M1. The polysiloxane structure represented by SP1 is *-(Si(CH3)2-O) because it results in a higher degree of orientation of the resulting optically absorbing anisotropic layer. n3 A group represented by -* is preferred, where n3 represents an integer of 6 to 10, and * represents the bonding position to L1 or M1. The fluorinated alkylene structure represented by SP1 is *-(CF2-CF2) because it increases the degree of orientation of the resulting optically absorbing anisotropic layer. n4 A group represented by -* is preferred, where n4 represents an integer of 6 to 10, and * represents the bonding position to L1 or M1.

[0045] The mesogenic group represented by M1 is a group that represents the main skeleton of the liquid crystal molecule, which contributes to the formation of liquid crystals. The liquid crystal molecules exhibit liquid crystallinity, which is a state (mesophase) intermediate between the crystalline state and the isotropic liquid state. There are no particular limitations on the mesogenic group, and reference can be made, for example, to the description in "Flussige Kristalle in Tabellen II" (VEB Deutsche Verlag fur Grundstoff Industrie, Leipzig, published in 1984), particularly pages 7 to 16, and the description in "Liquid Crystal Handbook" edited by the Liquid Crystal Handbook Editorial Committee (Maruzen, published in 2000) (particularly Chapter 3). The mesogenic group is preferably, for example, a group having at least one cyclic structure selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group, and an alicyclic group. The mesogenic group preferably has an aromatic hydrocarbon group, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups, because this results in a higher degree of orientation in the resulting light absorption anisotropic layer.

[0046] As the mesogenic group, from the viewpoints of the expression of liquid crystallinity, adjustment of the liquid crystal phase transition temperature, availability of raw materials, and suitability for synthesis, as well as the superior effects of the present invention, a group represented by the following formula (M1-A) or (M1-B) is preferred, and a group represented by formula (M1-B) is more preferred.

[0047] [ka]

[0048] In formula (M1-A), A1 is a divalent group selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group, and an alicyclic group, which may be substituted with an alkyl group, a fluorinated alkyl group, an alkoxy group, or a substituent. The divalent group represented by A1 is preferably a 4- to 6-membered ring. The divalent group represented by A1 may be a monocyclic ring or a condensed ring. * indicates the binding position to SP1 or T1.

[0049] Examples of the divalent aromatic hydrocarbon group represented by A1 include a phenylene group, a naphthylene group, a fluorene-diyl group, an anthracene-diyl group, and a tetracene-diyl group. From the viewpoints of the diversity of mesogenic skeleton designs and the availability of raw materials, a phenylene group or a naphthylene group is preferred, and a phenylene group is more preferred.

[0050] The divalent heterocyclic group represented by A1 may be either aromatic or non-aromatic, but is preferably a divalent aromatic heterocyclic group from the viewpoint of further improving the degree of orientation. Atoms other than carbon that constitute a divalent aromatic heterocyclic group include a nitrogen atom, a sulfur atom, and an oxygen atom. When an aromatic heterocyclic group has multiple atoms that constitute the ring other than carbon, these atoms may be the same or different. Specific examples of the divalent aromatic heterocyclic group include a pyridylene group (pyridine-diyl group), a pyridazine-diyl group, an imidazole-diyl group, a thienylene (thiophene-diyl group), a quinolylene group (quinoline-diyl group), an isoquinolylene group (isoquinoline-diyl group), an oxazole-diyl group, a thiazole-diyl group, an oxadiazole-diyl group, a benzothiazole-diyl group, a benzothiadiazole-diyl group, a phthalimido-diyl group, a thienothiazole-diyl group, a thiazolothiazole-diyl group, a thienothiophene-diyl group, and a thienoxazole-diyl group.

[0051] Specific examples of the divalent alicyclic group represented by A1 include a cyclopentylene group and a cyclohexylene group.

[0052] In formula (M1-A), a1 represents an integer of 1 to 10. When a1 is 2 or more, multiple A1 may be the same or different.

[0053] In formula (M1-B), A2 and A3 each independently represent a divalent group selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group, and an alicyclic group. Specific examples and preferred embodiments of A2 and A3 are the same as those of A1 in formula (M1-A), and therefore, description thereof will be omitted. In formula (M1-B), a2 represents an integer of 1 to 10. When a2 is 2 or greater, multiple A2s may be the same or different, multiple A3s may be the same or different, and multiple LA1s may be the same or different. a2 is preferably an integer of 2 or greater, and more preferably 2, because the degree of orientation of the resulting optically absorptive anisotropic layer will be higher. In formula (M1-B), when a2 is 1, LA1 is a divalent linking group. When a2 is 2 or more, each of the multiple LA1 is independently a single bond or a divalent linking group, and at least one of the multiple LA1 is a divalent linking group. When a2 is 2, it is preferable that one of the two LA1 is a divalent linking group and the other is a single bond, because this increases the degree of orientation of the resulting optically absorptive anisotropic layer.

[0054] In formula (M1-B), the divalent linking group represented by LA1 is -O-, -(CH2) g -, -(CF2) g -, -Si(CH3)2-, -(Si(CH3)2O) g -, -(OSi(CH3)2) g -(g represents an integer from 1 to 10.), -N(Z)-, -C(Z)=C(Z')-, -C(Z)=N-, -N=C(Z)-, -C(Z)2- C(Z')2-, -C(O)-, -OC(O)-, -C(O)O-, -OC(O)O-, -N(Z)C(O)-, -C(O)N(Z)-, - C(Z)=C(Z')-C(O)O-, -OC(O)-C(Z)=C(Z')-, -C(Z)=N-, -N=C(Z)-, -C(Z)=C( Z')-C(O)N(Z”)-, -N(Z”)-C(O)-C(Z)=C(Z')-, -C(Z)=C(Z')-C(O)-S-, -SC( Examples include -O)-C(Z)=C(Z')-, -C(Z)=NN=C(Z')- (Z, Z', and Z" independently represent hydrogen, a C1-C4 alkyl group, a cycloalkyl group, an aryl group, a cyano group, or a halogen atom), -C≡C-, -N=N-, -S-, -S(O)-, -S(O)(O)-, -(O)S(O)O-, -O(O)S(O)O-, -SC(O)-, and -C(O)S-. Of these, -C(O)O- is preferred because it results in a higher degree of orientation of the obtained optically absorptive anisotropic layer. LA1 may be a group combining two or more of these groups.

[0055] Specific examples of M1 include the following structures: In the specific examples below, "Ac" represents an acetyl group.

[0056] [ka]

[0057] [ka]

[0058] Examples of the terminal group represented by T1 include a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an alkoxycarbonyloxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms (ROC(O)-: R is an alkyl group), an acyloxy group having 1 to 10 carbon atoms, an acylamino group having 1 to 10 carbon atoms, an alkoxycarbonylamino group having 1 to 10 carbon atoms, a sulfonylamino group having 1 to 10 carbon atoms, a sulfamoyl group having 1 to 10 carbon atoms, a carbamoyl group having 1 to 10 carbon atoms, a sulfinyl group having 1 to 10 carbon atoms, a ureido group having 1 to 10 carbon atoms, and a (meth)acryloyloxy group-containing group. Examples of the (meth)acryloyloxy group-containing group include a group represented by -LA (L represents a single bond or a linking group. Specific examples of the linking group are the same as those of L1 and SP1 described above. A represents a (meth)acryloyloxy group). T1 is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and even more preferably a methoxy group, because this increases the degree of orientation of the resulting optically absorptive anisotropic layer. These terminal groups may be further substituted with these groups or polymerizable groups described in JP-A-2010-244038. The number of atoms in the main chain of T1 is preferably 1 to 20, more preferably 1 to 15, even more preferably 1 to 10, and particularly preferably 1 to 7, because this increases the degree of orientation of the resulting optically absorptive anisotropic layer. Having 20 or fewer atoms in the main chain of T1 further improves the degree of orientation of the polarizer. Here, the "main chain" in T1 refers to the longest molecular chain bonding to M1, and hydrogen atoms are not counted in the number of atoms in the main chain of T1. For example, when T1 is an n-butyl group, the number of atoms in the main chain is 4, and when T1 is a sec-butyl group, the number of atoms in the main chain is 3.

[0059] The content of the repeating unit (1) is preferably 20 to 100% by mass relative to 100% by mass of all repeating units contained in the polymeric liquid crystal compound, because this increases the degree of orientation of the resulting light absorption anisotropic layer. In this specification, the content of each repeating unit contained in the polymeric liquid crystal compound is calculated based on the amount (mass) of each monomer charged to obtain each repeating unit. The polymeric liquid crystalline compound may contain one type of repeating unit (1) alone or two or more types of repeating units (1). In particular, it is preferred that the polymeric liquid crystalline compound contain two types of repeating units (1) because this will result in a higher degree of orientation of the resulting light absorption anisotropic layer.

[0060] When a polymeric liquid crystalline compound contains two types of repeating units (1), it is preferable that the terminal group represented by T1 in one (repeating unit A) is an alkoxy group, and the terminal group represented by T1 in the other (repeating unit B) is a group other than an alkoxy group, because this results in a higher degree of orientation of the resulting light absorption anisotropic layer. The terminal group represented by T1 in the repeating unit B is preferably an alkoxycarbonyl group, a cyano group, or a (meth)acryloyloxy group-containing group, more preferably an alkoxycarbonyl group or a cyano group, because this results in a higher degree of orientation of the resulting optically absorbing anisotropic layer. The ratio (A / B) of the content of the repeating unit A in the polymeric liquid crystalline compound to the content of the repeating unit B in the polymeric liquid crystalline compound is preferably 50 / 50 to 95 / 5, more preferably 60 / 40 to 93 / 7, and even more preferably 70 / 30 to 90 / 10, because this results in a higher degree of orientation of the resulting light absorption anisotropic layer.

[0061] (Repeating unit (3-2)) The polymeric liquid crystalline compound may further contain a repeating unit represented by the following formula (3-2) (also referred to as "repeating unit (3-2)" in this specification), which has the advantages of improving the solubility of the polymeric liquid crystalline compound in a solvent and facilitating the adjustment of the liquid crystal phase transition temperature. The repeating unit (3-2) differs from the repeating unit (1) in that it does not have at least a mesogenic group. When the polymeric liquid crystalline compound contains the repeating unit (3-2), the polymeric liquid crystalline compound may be a copolymer of the repeating unit (1) and the repeating unit (3-2), or may further be a copolymer containing repeating units A and B. The copolymer may be any polymer, such as a block polymer, an alternating polymer, a random polymer, or a graft polymer.

[0062] [ka]

[0063] In formula (3-2), P3 represents the main chain of the repeating unit, L3 represents a single bond or a divalent linking group, SP3 represents a spacer group, and T3 represents a terminal group. Specific examples of P3, L3, SP3 and T3 in formula (3-2) are the same as P1, L1, SP1 and T1 in formula (1) above, respectively. Here, T3 in formula (3-2) preferably has a polymerizable group, from the viewpoint of improving the strength of the light absorption anisotropic layer.

[0064] When the repeating unit (3-2) is contained, the content thereof is preferably from 0.5 to 40% by mass, more preferably from 1 to 30% by mass, based on 100% by mass of all repeating units contained in the polymeric liquid crystal compound. The polymeric liquid crystal compound may contain one type of repeating unit (3-2) alone or two or more types of repeating units (3-2). When two or more types of repeating units (3-2) are contained, the total amount thereof is preferably within the above range.

[0065] (Weight average molecular weight) The weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably 1,000 to 500,000, more preferably 2,000 to 300,000, because this will result in a higher degree of orientation in the resulting light absorption anisotropic layer. When the Mw of the polymer liquid crystal compound is within the above range, the polymer liquid crystal compound is easy to handle. In particular, from the viewpoint of suppressing cracks during application, the weight average molecular weight (Mw) of the polymeric liquid crystal compound is preferably 10,000 or more, and more preferably 10,000 to 300,000. In addition, from the viewpoint of the temperature latitude of the degree of orientation, the weight average molecular weight (Mw) of the polymer liquid crystal compound is preferably less than 10,000, and more preferably 2,000 or more and less than 10,000. The weight average molecular weight and number average molecular weight described in this specification are values ​​measured by gel permeation chromatography (GPC). Solvent (eluent): N-methylpyrrolidone ·Device name: TOSOH HLC-8220GPC Column: Three TOSOH TSKgel Super AWM-H (6 mm x 15 cm) columns connected together Column temperature: 25℃ Sample concentration: 0.1% by mass ·Flow rate: 0.35mL / min Calibration curve: TOSOH TSK standard polystyrene. Calibration curves are based on seven samples with Mw = 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06).

[0066] (Content) The content of the liquid crystal compound is preferably from 50 to 99% by mass, more preferably from 70 to 96% by mass, of the solid content in the composition for forming an optically absorptive anisotropic layer. Here, the term "solid content in the composition for forming an optically absorptive anisotropic layer" refers to components excluding the solvent. Specific examples of the solid content include the liquid crystal compound, the dichroic material described below, the polymerization initiator, and the surfactant.

[0067] <Dichroic substances> The composition for forming the optically absorptive anisotropic layer contains a dichroic material. The dichroic material is not particularly limited, and known dichroic materials (dichroic dyes) can be used, such as visible light absorbing materials (dichroic dyes), luminescent materials (fluorescent materials, phosphorescent materials), ultraviolet absorbing materials, infrared absorbing materials, nonlinear optical materials, carbon nanotubes, and inorganic materials (e.g., quantum rods). Examples of dichroic materials include those described in paragraphs

[0067] to

[0071] of JP 2013-228706 A, paragraphs

[0008] to

[0026] of JP 2013-227532 A, paragraphs

[0008] to

[0015] of JP 2013-209367 A, paragraphs

[0045] to

[0058] of JP 2013-14883 A, paragraphs

[0012] to

[0029] of JP 2013-109090 A, and paragraphs

[0013] to

[0029] of JP 2013-101328 A. Paragraphs

[009] to

[0017] , paragraphs

[0051] to

[0065] of JP 2013-37353 A, paragraphs

[0049] to

[0073] of JP 2012-063387 A, paragraphs

[0016] to

[0018] of JP 11-305036 A, paragraphs

[0009] to

[0011] of JP 2001-133630 A, paragraphs

[0030] to

[0169] of JP 2011-215337 A, and paragraphs

[002] to [003 Paragraphs

[0011] to

[0025] of JP 2010-215846 A, paragraphs

[0017] to

[0069] of JP 2011-048311 A, paragraphs

[0013] to

[0133] of JP 2011-213610 A, paragraphs

[0074] to

[0246] of JP 2011-237513 A, paragraphs

[0005] to

[0051] of JP 2016-006502 A, and paragraphs

[0005] to

[0051] of WO 2016 / 060173 A.

[005] to

[0041] of WO 2016 / 136561,

[0008] to

[0062] of WO 2017 / 154835,

[0014] to

[0033] of WO 2017 / 154695,

[0014] to

[0033] of WO 2017 / 195833,

[0013] to

[0037] of WO 2017 / 195833, and

[0014] to

[0034] of WO 2018 / 164252.

[0068] The optically absorptive anisotropic layer may contain two or more dichroic substances. For example, from the viewpoint of making the resulting liquid crystal layer closer to black, it is preferable to use a combination of 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.

[0069] The dichroic substance contained in the composition for forming the light absorption anisotropic layer may have a crosslinkable group. In particular, from the viewpoint of suppressing a change in the polarization degree upon heating, it is preferable that the dichroic substance have a crosslinkable group. Examples of the crosslinkable group include a (meth)acryloyl group, an epoxy group, an oxetanyl group, and a styryl group, and among these, a (meth)acryloyl group is preferred.

[0070] (Content) The content of the dichroic substance in the composition for forming an optically absorptive anisotropic layer is preferably 1 to 400 parts by mass, more preferably 2 to 100 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the liquid crystal compound, because this increases the degree of orientation of the dichroic substance.

[0071] <Surfactant> The composition for forming the optically absorptive anisotropic layer may contain a surfactant. As the surfactant contained in the composition for forming the optically absorptive anisotropic layer, known surfactants can be used, but a copolymer having a repeating unit containing a fluorinated alkyl group (hereinafter also abbreviated as "repeating unit F") and a repeating unit containing a ring structure (hereinafter also abbreviated as "repeating unit M") is preferred.

[0072] (Repeating unit F) The repeating unit F contained in the copolymer is preferably a repeating unit represented by the following formula (a). [ka]

[0073] In the above formula (a), Ra1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R a2 represents an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, at least one of which has a fluorine atom as a substituent.

[0074] In the above formula (a), R a2 is preferably an alkyl group having 1 to 10 carbon atoms or an alkenylene group having 2 to 10 carbon atoms, at least one of which has a fluorine atom as a substituent, and more preferably an alkyl group having 1 to 10 carbon atoms, because this further suppresses alignment defects in the resulting optical absorption anisotropic layer. a2 It is more preferable that half or more of the carbon atoms contained in the group have fluorine atoms as substituents.

[0075] The repeating unit F contained in the copolymer is more preferably a repeating unit represented by the following formula (b). [ka]

[0076] In the above formula (b), R a1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, ma and na each independently represent an integer of 0 or more, and X represents a hydrogen atom or a fluorine atom. Here, ma is preferably an integer of 1 or more and 10 or less, and na is preferably an integer of 4 or more and 12 or less.

[0077] Examples of the monomer forming the repeating unit F in the copolymer (hereinafter also referred to as "fluoroalkyl group-containing monomer") include 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3,3-pentafluoropropyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorodecyl)ethyl (meth)acrylate, 2-(perfluoro-3-methylbutyl)ethyl (meth)acrylate, 2-(perfluoro-5-methylhexyl)ethyl (meth)acrylate, 2-(perfluoro-7-methyloctyl)ethyl (meth)acrylate, 1H,1H,3H-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,7H-dodecafluoroheptyl (meth)acrylate, 1H,1H,9H-hexadecafluorononyl (meth)acrylate, 1H-1-(trifluoromethyl)trifluoroethyl (meth)acrylate, 1H,1H,3H-hexafluorobutyl (meth)acrylate, 3-perfluorobutyl-2-hydroxypropyl (meth)acrylate, 3-perfluorohexyl-2-hydroxypropyl (meth)acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth)acrylate, 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl (meth)acrylate, 3-(perfluoro-5-methylhexyl)-2-hydroxypropyl (meth)acrylate, and 3-(perfluoro-7-methyloctyl)-2-hydroxypropyl (meth)acrylate.

[0078] From the viewpoint of reactivity and surface modification effect, the proportion of the fluoroalkyl group-containing monomer to be copolymerized is preferably 0.01 to 100 mol, more preferably 0.1 to 50 mol, and even more preferably 1 to 30 mol, per 1 mol of the monomer having a mesogenic group, which will be described later.

[0079] (Repeating unit M) The repeating unit M in the copolymer may be any unit containing a ring structure. The ring structure may be, for example, at least one ring structure selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group, and an alicyclic group. From the viewpoint of suppressing alignment defects, it is preferable that the repeating unit M has two or more ring structures.

[0080] The repeating unit M contained in the copolymer is more preferably a repeating unit represented by the following formula (b). [ka]

[0081] In the above formula (c), R a1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, L4 and L5 each independently represent a single bond or an alkylene group having 1 to 8 carbon atoms, G1 and G2 each independently represent a divalent cyclic group, and T4 represents a terminal group. n represents an integer of 0 to 4. When n represents an integer of 2 to 4, two or more L5s may be the same or different, and two or more G2s may be the same or different.

[0082] With respect to the alkylene group represented by L4 and L5, one or more -CH2- constituting the alkylene group may be a single bond, -O-, -S-, -NR 31 -, -C(=O)-, -C(=S)-, -CR 32 =CR 32 -, -C≡C-, -SiR 33 R 34 -, -N=N-, -CR 35 =NN=CR 36 -, -CR 37 may be replaced by at least one group selected from the group consisting of =N- and -SO2-; 31 ~R 37 each independently represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, or a linear or branched alkyl group having 1 to 10 carbon atoms. Furthermore, when L4 or L5 represents an alkylene group, a hydrogen atom contained in one or more -CH2- groups constituting the alkylene group may be replaced by at least one group selected from the group consisting of a halogen atom, a cyano group, a nitro group, a hydroxyl group, a linear alkyl group having 1 to 10 carbon atoms, and a branched alkyl group having 1 to 10 carbon atoms. Among these, an alkyleneoxy group having 4 to 6 carbon atoms and oxygen at the terminal is preferred for L4, and an ester group is preferred for L5.

[0083] The divalent cyclic groups represented by G1 and G2 each independently represent a divalent alicyclic hydrocarbon group or aromatic hydrocarbon group having 5 to 8 carbon atoms, and one or more of the -CH2- moieties constituting the alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NH-. Furthermore, the divalent cyclic group may be a divalent group formed by single-bonding multiple groups selected from alicyclic hydrocarbon groups and aromatic hydrocarbon groups. Of these, a benzene ring is preferred.

[0084] Examples of the terminal group represented by T4 include a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an alkoxycarbonyloxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms (ROC(O)-: R is an alkyl group having 1 to 10 carbon atoms), an acyloxy group having 1 to 10 carbon atoms, an acylamino group having 1 to 10 carbon atoms, an alkoxycarbonylamino group having 1 to 10 carbon atoms, a sulfonylamino group having 1 to 10 carbon atoms, a sulfamoyl group having 1 to 10 carbon atoms, a carbamoyl group having 1 to 10 carbon atoms, a sulfinyl group having 1 to 10 carbon atoms, a ureido group having 1 to 10 carbon atoms, and a (meth)acryloyloxy group-containing group. Of these, a hydrogen atom or a cyano group is preferred.

[0085] The molar ratio of repeating unit F to all repeating units contained in the copolymer is preferably 50 mol % or more from the viewpoint of the degree of orientation, and is preferably 70 mol % or less from the viewpoint of repelling.

[0086] (Content) The content of the surfactant is preferably 0.05 to 15 parts by mass, more preferably 0.08 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the liquid crystal compound, because this results in a higher degree of orientation of the resulting light-absorbing anisotropic layer.

[0087] <Polymerization initiator> The composition for forming the optically absorptive anisotropic layer preferably contains a polymerization initiator. The polymerization initiator is not particularly limited, but is preferably a photosensitive compound, that is, a photopolymerization initiator. As the photopolymerization initiator, various compounds can be used without particular limitation. Specific examples of the photopolymerization initiator include α-carbonyl compounds (U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (U.S. Pat. No. 2,722,512), polynuclear quinone compounds (U.S. Pat. Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazole dimers and p-aminophenyl ketones (U.S. Pat. No. 3,549,313). No. 67), acridine and phenazine compounds (JP 60-105667 A and U.S. Pat. No. 4,239,850 A), oxadiazole compounds (U.S. Pat. No. 4,212,970 A), o-acyloxime compounds (JP 2016-027384 A, paragraph

[0065] ), and acylphosphine oxide compounds (JP 63-040799 A, JP 5-029234 A, JP 10-095788 A, and JP 10-029997 A). Commercially available photopolymerization initiators such as Irgacure 184, Irgacure 907, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure OXE-01, and Irgacure OXE-02, all manufactured by BASF, can also be used.

[0088] When the composition for forming an optically absorptive anisotropic layer contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 15 parts by mass, relative to 100 parts by mass of the total of the dichroic substance and the polymeric liquid crystalline compound in the composition for forming an optically absorptive anisotropic layer. When the content of the polymerization initiator is 0.01 part by mass or more, the durability of the optically absorptive anisotropic film is improved, and when it is 30 parts by mass or less, the degree of orientation of the optically absorptive anisotropic film is improved. The polymerization initiator may be used alone or in combination of two or more. When two or more polymerization initiators are used, the total amount thereof is preferably within the above range.

[0089] <Solvent> The composition for forming the optically absorptive anisotropic layer preferably contains a solvent from the viewpoint of workability and the like. Examples of the solvent include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, etc.), ethers (e.g., dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, cyclopentyl methyl ether, tetrahydropyran, dioxolane, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., benzene, toluene, xylene, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, trichloromethane, dichloroethane, dichlorobenzene, chlorotoluene, etc.), esters (e.g., acetic acid, Examples of suitable organic solvents include organic solvents such as methyl acetate, ethyl acetate, butyl acetate, and ethyl lactate, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, isopentyl alcohol, neopentyl alcohol, diacetone alcohol, and benzyl alcohol), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, and 1,2-dimethoxyethane), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and N-ethylpyrrolidone), and heterocyclic compounds (e.g., pyridine), as well as water. The solvent may be used alone or in combination of two or more kinds. Among these solvents, from the viewpoint of utilizing the effect of excellent solubility, ketones (particularly cyclopentanone or cyclohexanone), ethers (particularly tetrahydrofuran, cyclopentyl methyl ether, tetrahydropyran or dioxolane), or amides (particularly dimethylformamide, dimethylacetamide, N-methylpyrrolidone or N-ethylpyrrolidone) are preferred.

[0090] When the composition for forming an optically absorptive anisotropic layer contains a solvent, the content of the solvent is preferably 80 to 99 mass %, more preferably 83 to 97 mass %, and particularly preferably 85 to 95 mass %, relative to the total mass of the composition for forming an optically absorptive anisotropic layer. The solvent may be used alone or in combination of two or more. When two or more solvents are used, the total amount thereof is preferably within the above range.

[0091] The thickness of the optically absorptive anisotropic layer is not particularly limited, but from the viewpoint of thinning the optical element, it is preferably from 100 to 8000 nm, more preferably from 300 to 5000 nm.

[0092] <<Alignment film>> The polarizer A may further have an alignment film, and preferably has an alignment film from the viewpoint of the alignment of the absorption axis of the light absorption anisotropic layer. The alignment film is not particularly limited as long as it has an alignment function, but a photo-alignment film is preferred. The photo-alignment film that the polarizer A may have is not particularly limited as long as it is an alignment film that exhibits an alignment function upon light irradiation, and any known photo-alignment film can be used.

[0093] The material for forming the photo-alignment film is not particularly limited, but may be a photo-alignment agent. The photo-alignment film is formed using, for example, a composition for forming a photo-alignment film containing the photo-alignment agent. The photo-alignment agent is a compound having a photo-alignment group. The compound having a photo-alignment group may be a polymer having a repeating unit containing a photo-alignment group. The photo-alignable group is a functional group that can impart anisotropy to a film by light irradiation. More specifically, it is a group whose molecular structure can be changed by light (e.g., linearly polarized light) irradiation. Typically, it refers to a group that undergoes at least one photoreaction selected from a photoisomerization reaction, a photodimerization reaction, and a photodecomposition reaction by light (e.g., linearly polarized light) irradiation. Among these photo-alignable groups, groups that undergo a photoisomerization reaction (groups having a photoisomerizable structure) or groups that undergo a photodimerization reaction (groups having a photodimerizable structure) are preferred, and groups that undergo a photodimerization reaction are more preferred.

[0094] The photoisomerization reaction is a reaction in which stereoisomerization or structural isomerization is caused by the action of light. Known examples of substances that undergo such photoisomerization reactions include substances having an azobenzene structure (K. Ichimura et al., Mol. Cryst. Liq. Cryst., 298, page 221 (1997)), substances having a hydrazono-β-ketoester structure (S. Yamamura et al., Liquid Crystals, vol. 13, No. 2, page 189 (1993)), substances having a stilbene structure (J.G. Victor and J.M. Torkelson, Macromolecules, 20, page 2241 (1987)), groups having a cinnamoyl cinnamate structure (skeleton), and substances having a spiropyran structure (K. Ichimura et al., Chemistry Letters, page 1063 (1992); K. Ichimura et al., Thin Solid Films, vol. 235, page 101 (1993)). The photoisomerization group is preferably a photoisomerization group containing a C=C bond or an N=N bond, and examples of such groups include a group having an azobenzene structure (skeleton), a group having a hydrazono-β-ketoester structure (skeleton), a group having a stilbene structure (skeleton), a group having a cinnamoyl structure (skeleton), and a group having a spiropyran structure (skeleton). Among these groups, a group having a cinnamoyl structure or a group having a coumarin structure is preferred, and a group having a cinnamoyl structure is more preferred.

[0095] The photodimerization reaction is an addition reaction between two groups under the action of light, typically forming a ring structure. Examples of substances that undergo such photodimerization include substances with cinnamic acid structures (M. Schadt et al., J. Appl. Phys., vol. 31, No. 7, page 2155 (1992)), substances with coumarin structures (M. Schadt et al., Nature., vol. 381, page 212 (1996)), substances with chalcone structures (Toshihiro Ogawa et al., Liquid Crystal Symposium Lecture Proceedings, 2AB03 (1997)), and substances with benzophenone structures (YK Jang et al., SID Int. Symposium Digest, P-53 (1997)). Examples of the group that undergoes the photodimerization reaction include a group having a cinnamic acid (cinnamoyl) structure (skeleton), a group having a coumarin structure (skeleton), a group having a chalcone structure (skeleton), a group having a benzophenone structure (skeleton), and a group having an anthracene structure (skeleton). Among these groups, a group having a cinnamoyl structure or a group having a coumarin structure is preferred, and a group having a cinnamoyl structure is more preferred.

[0096] The compound having the photoalignable group preferably further has a crosslinkable group. The crosslinkable group is preferably a thermally crosslinkable group that undergoes a curing reaction due to the action of heat, or a photocrosslinkable group that undergoes a curing reaction due to the action of light, and may be a crosslinkable group having both a thermally crosslinkable group and a photocrosslinkable group. Examples of the crosslinkable group include at least one selected from the group consisting of an epoxy group, an oxetanyl group, a group represented by -NH-CH2-OR (R represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms), a radical polymerizable group (a group having an ethylenically unsaturated double bond), and a blocked isocyanate group. Of these, an epoxy group, an oxetanyl group, or a group having an ethylenically unsaturated double bond is preferred. The three-membered cyclic ether group is also called an epoxy group, and the four-membered cyclic ether group is also called an oxetanyl group. Furthermore, examples of the radically polymerizable group (a group having an ethylenically unsaturated double bond) include a vinyl group, an allyl group, a styryl group, an acryloyl group, and a methacryloyl group, with an acryloyl group or a methacryloyl group being preferred.

[0097] One of the preferred embodiments of the photo-alignment film is a photo-alignment film formed using a composition for forming a photo-alignment film, which contains a polymer A having a repeating unit a1 containing a cinnamate group. In this specification, the cinnamate group refers to a group having a cinnamic acid structure containing cinnamic acid or a derivative thereof as the basic skeleton, and is represented by the following formula (I) or (II).

[0098] [ka]

[0099] In the formula, R 1 represents a hydrogen atom or a monovalent organic group, and R 2 represents a monovalent organic group. In formula (I), a represents an integer of 0 to 5, and in formula (II), a represents an integer of 0 to 4. When a is 2 or more, a plurality of R 1 may be the same or different. * indicates a bond.

[0100] The polymer A is not particularly limited as long as it is a polymer having a repeating unit a1 containing a cinnamate group, and any conventionally known polymer can be used. The weight average molecular weight of polymer A is preferably from 1,000 to 500,000, more preferably from 2,000 to 300,000, and even more preferably from 3,000 to 200,000. Here, the weight average molecular weight is defined as a polystyrene (PS) equivalent value measured by gel permeation chromatography (GPC). Measurement by GPC in the present invention can be performed using an HLC-8220GPC (manufactured by Tosoh Corporation) and TSKgel Super HZM-H, HZ4000, or HZ2000 as the column.

[0101] Examples of the repeating unit a1 containing a cinnamate group contained in the polymer A include repeating units represented by the following formulae (A1) to (A4).

[0102] [ka]

[0103] Here, in formula (A1) and formula (A3), R 3 represents a hydrogen atom or a methyl group, and in formula (A2) and formula (A4), R 4 represents an alkyl group having 1 to 6 carbon atoms. In formula (A1) and formula (A2), L 1 represents a single bond or a divalent linking group, a represents an integer of 0 to 5, and R 1 represents a hydrogen atom or a monovalent organic group. In formula (A3) and formula (A4), L 2 represents a divalent linking group, and R 2 represents a monovalent organic group. Also, L 1 Examples of the alkyl group include -CO-O-Ph-, -CO-O-Ph-Ph-, and -CO-O-(CH2) n -, -CO-O-(CH2) n -Cy- and -(CH2) n-Cy-, etc. In this formula, Ph represents a divalent benzene ring (e.g., a phenylene group) which may have a substituent, Cy represents a divalent cyclohexane ring (e.g., a cyclohexane-1,4-diyl group) which may have a substituent, and n represents an integer of 1 to 4. Also, L 2 Examples of the alkyl group include -O-CO- and -O-CO-(CH2) m Here, m represents an integer of 1 to 6. Also, R 1 Examples of the monovalent organic group include a chain or cyclic alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms which may have a substituent. Also, R 2 Examples of the monovalent organic group include a chain or cyclic alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 20 carbon atoms which may have a substituent. Also, a is preferably 1, and R 1 is preferably in the para position. Furthermore, examples of the substituent that the above-mentioned Ph, Cy and aryl groups may have include an alkyl group, an alkoxy group, a hydroxy group, a carboxy group, and an amino group.

[0104] The polymer A preferably further contains a repeating unit a2 containing a crosslinkable group, from the viewpoint of further improving the alignment of the optically absorptive anisotropic layer and further improving the adhesion of the optically absorptive anisotropic layer. The definition and preferred embodiments of the crosslinkable group are as described above. Among these, the repeating unit a2 containing a crosslinkable group is preferably a repeating unit containing an epoxy group, an oxetanyl group, or a group containing an ethylenically unsaturated double bond.

[0105] Preferred specific examples of repeating units having an epoxy group, an oxetanyl group, or a group having an ethylenically unsaturated double bond include the following repeating units. 3 and R 4are the above-mentioned formula (A1) and R in formula (A1), respectively. 3 and R 4 is synonymous with.

[0106] [ka]

[0107] The polymer A may have repeating units other than the repeating units a1 and a2. Examples of monomers that form other repeating units include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.

[0108] When the composition for forming a photo-alignment film contains an organic solvent described below, the content of the polymer A is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the organic solvent.

[0109] From the viewpoint of workability in producing a photo-alignment film, the composition for forming a photo-alignment film preferably contains a solvent. Examples of the solvent include water and organic solvents. Examples of the organic solvent include the organic solvents that may be contained in the composition for forming a light absorption anisotropic layer. The solvent may be used alone or in combination of two or more kinds.

[0110] The composition for forming a photo-alignment film may contain other components in addition to those described above, such as an acid generator, a crosslinking catalyst, an adhesion improver, a leveling agent, a surfactant, and a plasticizer. The method for forming a photo-alignment film using the composition for forming a photo-alignment film will be described later.

[0111] The polarizer A may have an alignment film other than the photo-alignment film. Other examples of alignment films include alignment films formed by techniques such as rubbing an organic compound (preferably a polymer) onto the film surface, oblique vapor deposition of an inorganic compound, formation of a layer with microgrooves, and accumulation of organic compounds (e.g., ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate, etc.) using the Langmuir-Blodgett method (LB film), as well as alignment films that exhibit alignment function when an electric field or magnetic field is applied.

[0112] When the polarizer A has an alignment film, the thickness thereof is not particularly limited, but is preferably from 100 to 2000 nm, more preferably from 400 to 1000 nm.

[0113] <<Polarizer A Manufacturing Method>> The manufacturing method of polarizer A is not particularly limited, and any known manufacturing method can be applied, as long as polarizer A has a curved surface and the absorption axis is oriented so that position Z that satisfies the specific requirements appears. A more specific example of a method for producing polarizer A is a method in which a photo-alignment film is formed on the surface of a resin substrate, and then a photo-absorption anisotropic layer is formed on the surface of the formed photo-alignment film using the above-mentioned composition for forming a photo-absorption anisotropic layer.

[0114] <Method for forming photo-alignment film> The method for forming the photo-alignment film is not particularly limited, and examples thereof include a manufacturing method having a coating step in which the above-mentioned composition for forming a photo-alignment film is applied to the surface of a resin substrate to form a coating film, and a light irradiation step in which the coating film of the composition for forming a photo-alignment film is irradiated with polarized or non-polarized light to form a photo-alignment film.

[0115] The coating step is a step of coating a photo-alignment film-forming composition onto the surface of a resin substrate to form a coating film. The method for applying the composition for forming a photo-alignment film is not limited, and examples thereof include roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet printing.

[0116] A photo-alignment film is formed by performing a light irradiation step of irradiating the coating film formed in the coating step with polarized or unpolarized light. When polarized light is used in the light irradiation step, the irradiation direction may be normal to the coating film surface or oblique to the coating film surface. When non-polarized light is used in the light irradiation step, the irradiation direction is oblique to the coating film surface. The light source used in the light irradiation step may be any of various light sources such as infrared light, visible light, or ultraviolet light, but ultraviolet light is preferred.

[0117] In particular, in the light irradiation step, it is preferable to irradiate the coating film with ultraviolet light (hereinafter also referred to as "polarized UV") whose polarization axis direction varies depending on the region passing through the coating film, so that the absorption axis of polarizer A is at position Z that satisfies the above-mentioned specific requirement, and it is more preferable to irradiate the coating film of a curved surface-shaped photo-alignment film-forming composition with the polarized UV. Methods for forming a curved coating film of the composition for forming a photo-alignment film include a method of forming a coating film of the composition for forming a photo-alignment film on the surface of a resin substrate molded into a curved shape, and a method of forming a coating film of the composition for forming a photo-alignment film on the surface of a flat resin substrate, and then molding a laminate of the resin substrate and the coating film of the composition for forming a photo-alignment film into a curved shape using the curved surface molding process described below. Another method of irradiating polarized UV light is to pass the UV light through a lens having a convex surface that is positioned closer to the UV light source than the coating film, and change the direction of the polarization axis of the UV light after passing through the lens depending on the position and focal length of the lens through which the UV light passes, thereby irradiating the UV light with a polarization axis direction that differs depending on the position of the coating film. By carrying out the light irradiation step on the coating film, an alignment film having curved portions and a plurality of regions in which the directions of the alignment regulating force are different from each other is formed.

[0118] <Method for forming optically absorptive anisotropic layer> The method for forming the optically absorptive anisotropic layer is not particularly limited, and examples thereof include a method comprising, in this order, a step of applying the above-mentioned optically absorptive anisotropic layer-forming composition to the surface of the photo-alignment film formed in the above-mentioned photo-alignment film-forming step to form a coating film (hereinafter also referred to as the "coating film forming step"), and a step of orienting the liquid crystalline component and / or dichroic material contained in the coating film (hereinafter also referred to as the "orientation step"). The liquid crystal component includes not only the liquid crystal compound described above, but also a dichroic substance having liquid crystallinity when the dichroic substance has liquid crystallinity. The optically absorptive anisotropic layer may be formed using the other alignment films described above instead of the photo-alignment film.

[0119] (Coating film formation process) The coating film forming step is a step of forming a coating film by applying the composition for forming an optically absorptive anisotropic layer to the surface of the substrate having a photo-alignment film on the photo-alignment film side. By using a composition for forming an optically absorbing anisotropic layer containing the above-mentioned solvent and / or by using a liquid such as a heated melt of the composition for forming an optically absorbing anisotropic layer, it becomes easier to apply the composition for forming an optically absorbing anisotropic layer to the surface of the photo-alignment film. Examples of methods for applying the composition for forming an optically absorptive anisotropic layer 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.

[0120] Among these, a spray method is preferred in which a coating liquid comprising the composition for forming an optically absorptive anisotropic layer is spray-coated to form a coating film of the composition for forming an optically absorptive anisotropic layer. Spray coating is a method in which a coating solution is sprayed in the form of fine droplets from a spray nozzle and applied to an object to be coated. One-fluid and two-fluid nozzles are available as types of nozzles, and both are applicable. There are various nozzle shapes depending on the discharge rate and spray pattern (fan-shaped, column-shaped, or shower-shaped), and all are applicable. In spray coating, the thickness of the coating film can be controlled by the concentration of the coating solution, the amount dispensed, and the distance between the substrate and the nozzle. For example, if the concentration of the coating solution is the same, a thicker coating film can be obtained by increasing the amount dispensed or by shortening the distance between the substrate and the nozzle. When spray coating is performed on a substrate having a curved surface or a substrate with a photo-alignment film (hereinafter also referred to as a "three-dimensional substrate"), it is preferable to place the three-dimensional substrate that will serve as a mold on a rotating stage, or to vacuum-adsorb the three-dimensional substrate with a spin chuck, and perform spray coating while rotating the three-dimensional substrate.

[0121] (Orientation process) The alignment step is a step of aligning the liquid crystal component contained in the coating film, thereby obtaining a light absorption anisotropic layer. The orientation step may include a drying treatment. By the drying treatment, components such as the solvent can be removed from the coating film. The drying treatment may be performed by leaving the coating film at room temperature for a predetermined time (for example, natural drying), or by heating and / or blowing air. Here, the liquid crystalline component contained in the composition for forming an optically absorptive anisotropic layer may be aligned by the above-mentioned coating film forming step or drying treatment. For example, in an embodiment in which the composition for forming an optically absorptive anisotropic layer is prepared as a coating liquid containing a solvent, the coating film is dried to remove the solvent from the coating film, thereby obtaining a coating film having optical absorption anisotropy (i.e., an optically absorptive anisotropic film). When the drying treatment is carried out at a temperature equal to or higher than the transition temperature of the liquid crystal component contained in the coating film to the liquid crystal phase, the heating treatment described below does not need to be carried out.

[0122] The transition temperature of the liquid crystalline component contained in the coating film to the liquid crystal phase is preferably 10 to 250°C, more preferably 25 to 190°C, from the viewpoint of manufacturability, etc. A transition temperature of 10°C or higher is preferred because it does not require a cooling process or the like to lower the temperature to the temperature range in which the liquid crystal phase is exhibited. Furthermore, a transition temperature of 250°C or lower is preferred because it does not require a high temperature even when the film is once converted to an isotropic liquid state at a temperature higher than the temperature range in which the liquid crystal phase is exhibited, thereby reducing waste of thermal energy and deformation and deterioration of the substrate.

[0123] The alignment step preferably includes a heat treatment, which allows the liquid crystal component contained in the coating film to be aligned, and therefore the heat-treated coating film can be suitably used as an optically absorptive anisotropic film. From the viewpoint of manufacturability, the heat treatment temperature is preferably 10 to 250° C., more preferably 25 to 190° C. The heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0124] The alignment step may include a cooling treatment carried out after the heating treatment. The cooling treatment is a treatment in which the coated film after heating is cooled to about room temperature (20 to 25°C). This allows the alignment of the liquid crystalline component contained in the coated film to be fixed. The cooling method is not particularly limited and can be carried out by a known method. Through the above steps, an optically absorptive anisotropic film can be obtained. In this embodiment, the liquid crystal component contained in the coating film is aligned by drying treatment, heating treatment, or the like, but the method is not limited thereto and can be implemented by any known alignment treatment.

[0125] (Other processes) The method for forming the optically absorptive anisotropic layer may include a step of curing the optically absorptive anisotropic layer (hereinafter also referred to as a "curing step") after the above alignment step. For example, when the optically absorptive anisotropic layer has a crosslinkable group (polymerizable group), the curing step is carried out by heating and / or light irradiation (exposure). Among these, the curing step is preferably carried out by light irradiation. The light source used for curing can be various light sources such as infrared light, visible light, or ultraviolet light, but ultraviolet light is preferred. Furthermore, ultraviolet light may be irradiated while heating during curing, or ultraviolet light may be irradiated through a filter that transmits only specific wavelengths. When the exposure is carried out while heating, the heating temperature during exposure is preferably 25 to 140° C., although it depends on the transition temperature to the liquid crystal phase of the liquid crystal component contained in the liquid crystal film. The exposure may be carried out in a nitrogen atmosphere. When the curing of the liquid crystal film proceeds by radical polymerization, the exposure is preferably carried out in a nitrogen atmosphere, since this reduces the inhibition of polymerization by oxygen.

[0126] <Curved surface forming process> It is preferable that the method for producing polarizer A further includes a step of forming a member selected from the group consisting of a planar substrate, a laminate having the planar substrate, and a planar polarizer into a curved surface by thermoforming or vacuum forming (hereinafter also referred to as a "curved surface forming step"). Methods for forming the above-mentioned components into a curved surface include, for example, insert molding as described in JP 2004-322501 A, and molding methods such as vacuum forming, injection molding, pressure forming, reduced pressure coating molding, in-mold transfer, and mold pressing as described in WO 2010 / 001867 and JP 2012-116094 A. It is also preferable to heat the member when shaping it into a curved surface. The heating temperature is preferably 80 to 170°C, more preferably 100 to 150°C, and even more preferably 110 to 140°C. Alternatively, polarizer A may be produced by preparing a resin substrate having a curved surface in advance, and then forming a photo-alignment film and a light-absorption anisotropic layer, if necessary, on the resin substrate having the curved surface.

[0127] A preferred method for producing the polarizer A is to form an alignment film having curved portions and a plurality of regions in which the directions of the alignment regulating force differ from one another by, for example, the method for forming a photo-alignment film on the surface of a resin substrate, and then form an optically absorbing anisotropic layer on the surface of the resulting alignment film by the method for forming an optically absorbing anisotropic layer described above. In this case, the method for forming the optically absorbing anisotropic layer preferably includes a step of applying the composition for forming an optically absorbing anisotropic layer described above to form the optically absorbing anisotropic layer, and more preferably forms the optically absorbing anisotropic layer by spray-coating the composition for forming an optically absorbing anisotropic layer described above. In particular, the method for producing polarizer A preferably involves carrying out the following steps in this order: a coating step in which a composition for forming a photo-alignment film is applied to the surface of a flat resin substrate to form a coating film; a curved surface forming step in which the resin substrate and the coating film are shaped into a curved shape; a light irradiation step in which polarized or unpolarized light is irradiated onto the curved coating film; a coating film formation step in which a composition for forming a light-absorbing anisotropic layer is applied (preferably by spray coating) to the surface of the formed photo-alignment film; and an alignment step in which the liquid crystalline component contained in the formed coating film is oriented. However, the method for producing the polarizer A is not limited to the above example.

[0128] [Polarizer B] The polarizer B is not particularly limited as long as it is an absorptive polarizer, and any known absorptive polarizer containing at least a dichroic material can be used. Examples of polarizer B include a polarizer in which a dichroic substance is dyed onto a film made of polyvinyl alcohol or other polymer resin, and the film is stretched to orient the dichroic substance, and a polarizer having a light-absorbing anisotropic layer in which a dichroic substance is oriented by utilizing the orientation of a liquid crystal compound, similar to polarizer A. Among these, a polarizer obtained by stretching polyvinyl alcohol dyed with iodine is preferred from the viewpoints of availability and increasing the degree of polarization.

[0129] When the optical element is used in an image display device, the polarizer B may be laminated on an image display element, such as a liquid crystal display device or an organic EL display device, that is included in the image display device. In other words, when the image display element has an absorptive polarizer on the viewing side, the absorptive polarizer may be used as the polarizer B. When the image display device does not have an absorptive polarizer, polarizer B may be provided on the viewing side of the image display device.

[0130] [Image display device] The image display device of the present invention includes at least the optical element and an image display element, and thereby, in an image display device using a reciprocating optical system having an absorptive polarizer with a curved surface portion, ghosting in an image displayed by the image display element can be further suppressed. The image display device can also incorporate optical components such as wavelength plates (such as λ / 4 plates and λ / 2 plates), reflective linear polarizers, reflective circular polarizers, absorptive polarizers other than polarizer A and polarizer B, half mirrors, and anti-reflection films.

[0131] [First embodiment] A first embodiment of an image display device according to the present invention will be described with reference to the drawings. FIG. 4 is a schematic diagram showing the configuration of the image display device according to the first embodiment. The image display device 20 shown in Figure 4 includes a polarizer A100, a reflective linear polarizer 200, a first λ / 4 plate 600, a half mirror 300, a second λ / 4 plate 700, a polarizer B400, an image display element 500, and a housing 24, and the image display device 20 has a position Z on a line L that satisfies specific requirements. Of the members included in the image display device 20, the polarizer A100, the reflective linear polarizer 200, the first λ / 4 plate 600, the half mirror 300, the second λ / 4 plate 700, and the polarizer B400 constitute the present optical elements.

[0132] As will be described in detail later, in the image display device 20, the light ray V is reflected by the reflective linear polarizer 200 and the half mirror 300, and then observed as a display image at position Z. That is, the light ray V has an optical path that travels back and forth between the reflective linear polarizer 200 and the half mirror 300. The image display device 20 of this embodiment is configured so that there is a position Z at which the polarizer A100 and the polarizer B400 satisfy specific requirements, thereby effectively suppressing ghosts that occur in the display image observed at position Z.

[0133] Each member included in the image display device according to this embodiment will be described below. Polarizer A and polarizer B have already been described. In addition, in the following description of the image display device, the definitions of positions X, Y, and Z, straight line L, and virtual lines L1 to L4 are the same as the definitions of positions X, Y, and Z, straight line L, and virtual lines L1 to L4 in the optical element already described.

[0134] <λ / 4 plate> The image display device according to this embodiment includes a first λ / 4 plate and a second λ / 4 plate. In this specification, when the term "λ / 4 plate" is used, it is intended that the description of its configuration, characteristics, etc. can be applied to both the first λ / 4 plate and the second λ / 4 plate without distinction. The λ / 4 plate included in the image display device according to this embodiment has a slow axis direction set so as to convert linearly polarized light into circularly polarized light and circularly polarized light into linearly polarized light. A λ / 4 plate (quarter-wave retardation plate) may have a retardation of approximately ¼ wavelength at any wavelength in the visible range. Examples of the λ / 4 plate include a retardation plate having a retardation of 120 to 150 nm at a wavelength of 550 nm, and a retardation plate having a retardation of approximately 138 nm (138±10 nm) at a wavelength of 550 nm is preferably used. From the viewpoint of suppressing ghosts in a displayed image and further improving display performance such as brightness and color reproducibility, it is preferable that the λ / 4 plate has reverse dispersion with respect to wavelength. Here, having reverse dispersion with respect to wavelength means that the value of retardation at that wavelength increases as the wavelength increases. As the λ / 4 plate, any known λ / 4 plate can be used without any limitation, and for example, a stretched polycarbonate film and a retardation film prepared by curing a liquid crystalline compound can be used. From the viewpoint of thinning, it is preferable to use a retardation film prepared by curing a liquid crystalline compound.

[0135] The first λ / 4 plate may have a curved surface. The first λ / 4 plate preferably has a surface of revolution in which the surface on the image display element side is convex and the surface on the viewer side is concave, and more preferably has a curved surface with a constant radius of curvature. When the first λ / 4 plate has a curved surface with a constant radius of curvature, the radius of curvature can be appropriately selected depending on the size and use of the optical element and image display device, but is preferably 20 to 1000 mm, more preferably 30 to 200 mm.

[0136] (slow axis of λ / 4 plate) In the image display device according to this embodiment, it is preferable that the angle between the local absorption axis of the first λ / 4 plate at the intersection of the line connecting position Z and polarizer B with the line of polarizer A and the local slow axis of the first λ / 4 plate at the intersection of the line with the line is 45°. More specifically, it is preferable that the first λ / 4 plate and polarizer A satisfy all of the following requirements. The angle between the direction of the absorption axis of polarizer A at position X and the direction of the slow axis of the first λ / 4 plate at the intersection of line L and the first λ / 4 plate is 45° when observed from the direction in which line L extends. The angle between the direction of the absorption axis of polarizer A at the intersection of virtual line L1 and polarizer A and the direction of the slow axis of the first λ / 4 plate at the intersection of virtual line L1 and the first λ / 4 plate is 45° when observed from the direction in which virtual line L1 extends. The angle between the direction of the absorption axis of polarizer A at the intersection of virtual line L2 and polarizer A and the direction of the slow axis of the first λ / 4 plate at the intersection of virtual line L2 and the first λ / 4 plate is 45° when observed from the direction in which virtual line L2 extends. The angle between the direction of the absorption axis of polarizer A at the intersection of virtual line L3 and polarizer A and the direction of the slow axis of the first λ / 4 plate at the intersection of virtual line L3 and the first λ / 4 plate is 45° when observed from the direction in which virtual line L3 extends. The angle between the direction of the absorption axis of polarizer A at the intersection of virtual line L4 and polarizer A and the direction of the slow axis of the first λ / 4 plate at the intersection of virtual line L4 and the first λ / 4 plate is 45° when observed from the direction in which virtual line L4 extends. If the slow axis of the first λ / 4 plate satisfies all of the above requirements, ghosts can be effectively suppressed over the entire area of ​​the optical element.

[0137] In the image display device according to this embodiment, it is preferable that the following relationship be satisfied across the entire region of polarizer B: assuming a line Lz connecting position Z and polarizer B, the angle between the direction of the local absorption axis of polarizer A at the intersection with line Lz and the local slow axis of the first λ / 4 plate at the intersection with line Lz is 45° when observed from the direction of line Lz. Satisfying the above relationship across the entire region of polarizer B means that the above relationship is satisfied regardless of the point on the viewing-side surface of polarizer B from which the line Lz connecting position Z is drawn. This makes it possible to more effectively suppress ghosting across the entire region of an image displayed by the image display device according to this embodiment.

[0138] Furthermore, in the image display device according to this embodiment, it is preferable that the local slow axis of the first λ / 4 plate at the intersection with the line connecting position Z and polarizer B and the local slow axis of the second λ / 4 plate at the intersection with the line are perpendicular to each other. More specifically, it is preferable that the first λ / 4 plate and the second λ / 4 plate satisfy all of the following requirements. The direction of the slow axis of the first λ / 4 plate at the intersection of the line L and the first λ / 4 plate and the direction of the slow axis of the second λ / 4 plate at the intersection of the line L and the second λ / 4 plate are perpendicular to each other when observed from the direction in which the line L extends. The direction of the slow axis of the first λ / 4 plate at the intersection of the virtual line L1 and the first λ / 4 plate and the direction of the slow axis of the second λ / 4 plate at the intersection of the virtual line L1 and the second λ / 4 plate are perpendicular to each other when observed from the direction in which the virtual line L1 extends. The direction of the slow axis of the first λ / 4 plate at the intersection of the virtual line L2 and the first λ / 4 plate and the direction of the slow axis of the second λ / 4 plate at the intersection of the virtual line L2 and the second λ / 4 plate are perpendicular to each other when observed from the direction in which the virtual line L2 extends. The direction of the slow axis of the first λ / 4 plate at the intersection of the virtual line L3 and the first λ / 4 plate and the direction of the slow axis of the second λ / 4 plate at the intersection of the virtual line L3 and the second λ / 4 plate are perpendicular to each other when observed from the direction in which the virtual line L3 extends. The direction of the slow axis of the first λ / 4 plate at the intersection of the virtual line L4 and the first λ / 4 plate and the direction of the slow axis of the second λ / 4 plate at the intersection of the virtual line L4 and the second λ / 4 plate are perpendicular to each other when observed from the direction in which the virtual line L4 extends. If the slow axis of the first λ / 4 plate and the slow axis of the second λ / 4 plate satisfy all of the above requirements, ghosts can be effectively suppressed over the entire area of ​​the optical element.

[0139] In the image display device according to this embodiment, assuming a straight line Lz connecting position Z and polarizer B, it is preferable that the relationship between position Z, the first λ / 4 plate, and the second λ / 4 plate such that the local slow axis of the first λ / 4 plate at the intersection with line Lz and the local slow axis of the second λ / 4 plate at the intersection with line Lz are orthogonal when observed from the direction in which line Lz extends is satisfied over the entire region of polarizer B. This makes it possible to more effectively suppress ghosts over the entire region of an image displayed by the image display device according to this embodiment.

[0140] The direction of the slow axis of the λ / 4 plate at the intersection of the straight line L or the virtual lines L1 to L4 with the λ / 4 plate can be measured by placing a first λ / 4 plate or a second λ / 4 plate in place of the polarizer A or the polarizer B in accordance with the method for measuring the direction of the absorption axis of the polarizer A or the polarizer B using AxoScan described above in [Method for identifying position Z].

[0141] <Reflective linear polarizer> The image display device according to this embodiment includes a reflective linear polarizer. The reflective linear polarizer has a function of reflecting a part of the light emitted from the image display element and causing it to travel back and forth within the optical system. From the viewpoint of suppressing ghosts, the reflective linear polarizer preferably has a high degree of polarization. The reflective linear polarizer may be any known reflective linear polarizer without limitation, and examples thereof include a film obtained by stretching a dielectric multilayer film as described in JP 2011-053705 A and a wire grid polarizer. Suitable commercially available reflective linear polarizers include a reflective polarizer (product name APF) manufactured by 3M and a wire grid polarizer (product name WGF) manufactured by Asahi Kasei Corporation.

[0142] The reflective linear polarizer may have a curved surface. The reflective linear polarizer preferably has a surface of rotation in which the surface on the image display element side is a convex surface and the surface on the viewing side is a concave surface, and more preferably has a curved surface with a constant radius of curvature. When the reflective linear polarizer has a curved surface with a constant radius of curvature, the radius of curvature can be appropriately selected depending on the size and use of the optical element and image display device, but is preferably 20 to 1000 mm, more preferably 30 to 200 mm.

[0143] In the image display device according to this embodiment, it is preferable that the reflection axis of the reflective linear polarizer is parallel to the local absorption axis of polarizer A at the intersection with the line connecting position Z and polarizer B, and the local reflection axis of the reflective linear polarizer at the intersection with the line connecting position Z and polarizer B. More specifically, it is preferable that the reflective linear polarizer and polarizer A satisfy all of the following requirements. The direction of the absorption axis of polarizer A at position X and the direction of the reflection axis of the reflective linear polarizer at the intersection of line L and the reflective linear polarizer are parallel when observed from the direction in which line L extends. The direction of the absorption axis of polarizer A at the intersection of virtual line L1 and polarizer A and the direction of the reflection axis of the reflective linear polarizer at the intersection of virtual line L1 and the reflective linear polarizer are parallel when observed from the direction in which virtual line L1 extends. The direction of the absorption axis of polarizer A at the intersection of virtual line L2 and polarizer A and the direction of the reflection axis of the reflective linear polarizer at the intersection of virtual line L2 and the reflective linear polarizer are parallel when observed from the direction in which virtual line L2 extends. The direction of the absorption axis of polarizer A at the intersection of virtual line L3 and polarizer A and the direction of the reflection axis of the reflective linear polarizer at the intersection of virtual line L3 and the reflective linear polarizer are parallel when observed from the direction in which virtual line L3 extends. The direction of the absorption axis of polarizer A at the intersection of virtual line L4 and polarizer A and the direction of the reflection axis of the reflective linear polarizer at the intersection of virtual line L4 and the reflective linear polarizer are parallel when observed from the direction in which virtual line L4 extends. When the local reflection axis of a reflective linear polarizer satisfies all of the above requirements, ghosting can be effectively suppressed over the entire area of ​​the optical element.

[0144] Furthermore, in the image display device according to this embodiment, assuming a straight line Lz connecting position Z and polarizer B, it is preferable that the relationship between position Z, polarizer A, and reflective linear polarizer, in which the absorption axis of polarizer A at the intersection with line Lz and the reflection axis of the reflective linear polarizer are parallel when observed from the direction in which line Lz extends, be satisfied over the entire region of polarizer B. This makes it possible to more effectively suppress ghosting over the entire region of an image displayed by the image display device according to this embodiment.

[0145] The direction of the reflection axis of the reflective linear polarizer at the intersection of the straight line L or the virtual lines L1 to L4 with the reflective linear polarizer can be measured by placing a reflective linear polarizer in place of polarizer A or polarizer B, in accordance with the method for measuring the direction of the absorption axis of polarizer A or polarizer B using AxoScan described above in [Method for identifying position Z].

[0146] <Half mirror> The image display device according to this embodiment includes a half mirror. The half mirror is not particularly limited, and known half mirrors can be used, such as a half mirror in which aluminum is vapor-deposited on a glass plate, and a half mirror in which aluminum is vapor-deposited on a transparent resin plate made of a resin such as polyethylene terephthalate (PET), cycloolefin polymer (COP), or polymethyl methacrylate (PMMA). The transmittance of the half mirror is not particularly limited, but is preferably 50±30%, more preferably 50±10%, and even more preferably 50%.

[0147] The half mirror may have a curved surface. The half mirror preferably has a surface of revolution in which the surface facing the image display element is convex and the surface facing the viewer is concave, and more preferably has a curved surface with a constant radius of curvature. When the half mirror has a curved surface with a constant radius of curvature, the radius of curvature can be appropriately selected depending on the size and use of the optical element and image display device, but is preferably 20 to 1000 mm, more preferably 30 to 200 mm.

[0148] <Image display element> As the image display element, known image display elements can be used, such as a liquid crystal display, an organic electroluminescence display, and a micro LED (Light Emitting Diode) display.

[0149] The housing is not particularly limited as long as it is a member that houses and supports the optical member, and a housing having an appropriate shape may be appropriately selected depending on the intended use of the image display device. Examples of the shape of the housing include the shape of goggles, the shape of a pair of eyeglass frames, and the shape of a helmet.

[0150] A specific usage mode of the image display device according to this embodiment will be described with reference to FIG. In the following explanation and in the explanation of the usage mode of the image display device according to the second embodiment described later, the direction in which the local absorption axis of polarizer A faces at the position where light ray V is incident on polarizer A will be referred to as the "horizontal direction," and the direction in which the local absorption axis of polarizer B faces at the position where light ray V is incident on polarizer B will be referred to as the "vertical direction." In addition, in the image display device 20, the image display element 500 emits unpolarized light, the slow axis of the λ / 4 plate 700 is set to convert horizontally linearly polarized light incident from the image display element 500 side into right-handed circularly polarized light, the slow axis of the λ / 4 plate 600 is set to convert left-handed circularly polarized light incident from the image display element 500 side into vertically linearly polarized light, and the reflection axis of the reflective linear polarizer 200 is set to be horizontal.

[0151] In the image display device 20 shown in FIG. 4, unpolarized light V emitted from the image display element 500 has its vertical component absorbed by the polarizer B400, becoming horizontally linearly polarized light, and then enters the λ / 4 plate 700. The horizontally linearly polarized light incident on the λ / 4 plate 700 is converted by the λ / 4 plate 700 into right-handed circularly polarized light, which then enters the half mirror 300 . Approximately half of the right-handed circularly polarized light incident on the half mirror 300 is transmitted through the half mirror 300 and enters the λ / 4 plate 600, and the remaining half is reflected. The right-handed circularly polarized light incident on the λ / 4 plate 600 from the image display element 500 side is converted by the λ / 4 plate 600 into horizontally linearly polarized light, which then enters the reflective linear polarizer 200 . As described above, since the reflection axis of the reflective linear polarizer 200 is horizontal, the horizontally linearly polarized light incident on the reflective linear polarizer 200 is reflected by the reflective linear polarizer 200 and enters the λ / 4 plate 600 again from the viewing side (position Z side) as horizontally linearly polarized light. The horizontally linearly polarized light incident on the λ / 4 plate 600 from the viewing side is converted by the λ / 4 plate 600 into right-handed circularly polarized light, and then incident on the half mirror 300 again. Approximately half of the right-handed circularly polarized light incident on the half mirror 300 is transmitted through the half mirror 300, and the remaining half is reflected by the half mirror 300 and enters the λ / 4 plate 600 three times as left-handed circularly polarized light. Left-handed circularly polarized light incident on the λ / 4 plate 600 from the image display element 500 side is converted into vertically linearly polarized light, which then enters the reflective linear polarizer 200 . The vertically linearly polarized light incident on the reflective linear polarizer 200 is transmitted through the reflective linear polarizer 200 and the polarizer A100, and reaches the viewing side (position Z).

[0152] In this manner, in the image display device 20 according to this embodiment, the light ray V emitted from the image display element 500 travels through a round trip optical path between the reflective linear polarizer 200 and the half mirror 300, and is observed as a display image at position Z. In the image display device 20 according to this embodiment, there is a position Z that satisfies a specific requirement. As a result, even if horizontally linearly polarized light that is incident on the reflective linear polarizer 200 for the first time is not sufficiently reflected and passes through the reflective linear polarizer 200, the horizontally linearly polarized light is absorbed by the polarizer A, which has an absorption axis in the horizontal direction, and therefore, transmission of light that does not travel through a round-trip optical path is suppressed, and ghosts in the observed display image can be suppressed. In particular, in the image display device 20 according to this embodiment, the effect of suppressing ghosting becomes more pronounced in the displayed image observed from position Z, the greater the angle between the line connecting position Z to the image display area and line L, in other words, the closer the image is displayed in an area closer to the periphery of the image display element 500.

[0153] Second Embodiment A second embodiment of the image display device according to the present invention will be described. FIG. 5 is a schematic diagram showing the configuration of an image display device according to the second embodiment. The image display device 22 shown in Figure 5 includes a polarizer A100, a first λ / 4 plate 600, a reflective circular polarizer 202, a half mirror 300, a second λ / 4 plate 700, a polarizer B400, an image display element 500, and a housing 24, and the image display device 22 has a position Z on a straight line L that satisfies specific requirements. Of the members included in the image display device 22, the polarizer A100, the first λ / 4 plate 600, the reflective circular polarizer 202, the half mirror 300, the second λ / 4 plate 700, and the polarizer B400 constitute this optical element.

[0154] In the image display device 22, the light ray V is reflected by the reflective circular polarizer 202 and the half mirror 300, and is observed as a display image at position Z. That is, the light ray V has an optical path that travels back and forth between the reflective circular polarizer 202 and the half mirror 300. The image display device 22 of this embodiment is configured so that there is a position Z at which the polarizer A100 and the polarizer B400 satisfy specific requirements, thereby effectively suppressing ghosts that occur in the display image observed at position Z.

[0155] Each member included in the image display device according to this embodiment will be described below. Polarizer A, polarizer B, first and second λ / 4 plates, half mirror, and image display element have been described above.

[0156] <Reflective circular polarizer> The image display device according to this embodiment includes a reflective circular polarizer. The reflective circular polarizer is a polarizer that transmits right-handed or left-handed circularly polarized light and reflects circularly polarized light that has the opposite rotation direction to the transmitted circularly polarized light, and in the image display device according to this embodiment, it has the function of reflecting a portion of the light emitted from the image display element and causing it to travel back and forth within the optical system. From the viewpoint of suppressing ghosts, the reflective circular polarizer preferably has a high degree of polarization. The reflective circular polarizer may be a reflective circular polarizer having a cholesteric liquid crystal layer. The cholesteric liquid crystal layer is a layer having a liquid crystal phase (cholesteric liquid crystal phase) in which the liquid crystal compound is in a cholesteric alignment state. As the reflective circular polarizer having a cholesteric liquid crystal layer, a film in which a liquid crystal compound is cured in a state exhibiting a cholesteric liquid crystal phase can be suitably used.

[0157] When a reflective circular polarizer is used, the light beam transmitted through the reflective circular polarizer becomes circularly polarized light, so an optical component that converts circularly polarized light into linearly polarized light, more specifically a first λ / 4 plate, is placed between polarizer A and the reflective circular polarizer. This converts the light beam transmitted through the reflective circular polarizer into linearly polarized light, which then enters polarizer A.

[0158] A specific usage mode of the image display device according to this embodiment will be described with reference to FIG. In the image display device 22, the image display element 500 emits unpolarized light, the slow axis of the λ / 4 plate 700 is set to convert horizontally linearly polarized light incident from the image display element 500 side into right-handed circularly polarized light, the slow axis of the λ / 4 plate 600 is set to convert left-handed circularly polarized light incident from the image display element 500 side into vertically linearly polarized light, and the reflective circular polarizer 202 reflects right-handed circularly polarized light and transmits left-handed circularly polarized light.

[0159] In the image display device 22 shown in FIG. 5, unpolarized light V emitted from the image display element 500 has its vertical component absorbed by the polarizer B400, becomes linearly polarized light in the horizontal direction, and then enters the λ / 4 plate 700. The horizontally linearly polarized light incident on the λ / 4 plate 700 is converted by the λ / 4 plate 700 into right-handed circularly polarized light, which then enters the half mirror 300 . Approximately half of the right-handed circularly polarized light incident on the half mirror 300 is transmitted through the half mirror 300 and enters the λ / 4 plate 600, and the remaining half is reflected. The right-handed circularly polarized light that has entered the reflective circular polarizer 202 is reflected by the reflective circular polarizer 202 and enters the half mirror 300 again as right-handed circularly polarized light. Approximately half of the right-handed circularly polarized light incident on the half mirror 300 is transmitted through the half mirror 300, and the remaining half is reflected by the half mirror 300, becomes left-handed circularly polarized light, and then enters the reflective circular polarizer 202 again. The left-handed circularly polarized light incident on the reflective circular polarizer 202 is transmitted through the reflective circular polarizer 202 and is incident on the λ / 4 plate 600 . The left-handed circularly polarized light incident on the λ / 4 plate 600 from the image display element 500 side is converted by the λ / 4 plate 600 into vertically linearly polarized light, which then enters the polarizer A100. The vertically linearly polarized light incident on the polarizer A100 passes through the polarizer A100 and reaches the viewing side (position Z).

[0160] In this manner, in the image display device 22 according to this embodiment, the light ray V emitted from the image display element 500 travels through a round trip optical path between the reflective circular polarizer 202 and the half mirror 300, and is observed as a display image at position Z. In the image display device 22 according to this embodiment, there is a position Z that satisfies a specific requirement. As a result, even if right-handed circularly polarized light that is incident on the reflective circular polarizer 202 for the first time is not sufficiently reflected and passes through the reflective circular polarizer 202, the transmitted right-handed circularly polarized light is converted into horizontally linearly polarized light by the λ / 4 plate 600 and then absorbed by the polarizer A having an absorption axis in the horizontal direction, thereby suppressing the transmission of light rays that do not travel through a round-trip optical path and suppressing ghosts in the displayed image that is observed. In particular, in the image display device 22 according to this embodiment, the effect of suppressing ghosting becomes more pronounced in the displayed image observed from position Z, the greater the angle between the line connecting position Z to the image display area and line L, in other words, the closer the image is displayed in an area closer to the periphery of the image display element 500.

[0161] The configuration of the image display device according to the present invention is not limited to the above embodiment. The image display device may include other functional layers in addition to those described above, such as an adhesive layer, a bonding layer, an anti-reflection layer, and a protective layer. In addition to at least polarizer A, polarizer B, and the image display device, the image display device preferably further comprises two optical members selected from the group consisting of a reflective linear polarizer, a reflective circular polarizer, and a half mirror, and more preferably further comprises one of a reflective linear polarizer and a reflective circular polarizer, and a half mirror.

[0162] The method for producing an image display device is not particularly limited and may include a step of preparing each of the optical members and bonding them together with a pressure-sensitive adhesive or adhesive. Alternatively, the method may include a step of transferring an optical member formed on a temporary substrate to another optical member. Each step can be carried out according to a known method.

[0163] [Use of image display device] Although the use of the image display device is not particularly limited, it is preferably used as a near-eye display because ghosting in the displayed image is suppressed and it is easy to make it small and thin. More specifically, the image display device can be used as an image display device attached to optical devices such as a virtual reality display device, an augmented reality display device, an electronic finder used in a digital camera, an optical telescope, and an optical microscope. [Example]

[0164] 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.

[0165] [Example 1] <Preparation of photo-alignment film> The coating solution PA1 for forming a photo-alignment film, which will be described later, was continuously applied with a wire bar to a resin substrate "Technoloy C001" (polycarbonate / PMMA laminated substrate, 75 μm thick) manufactured by Sumitomo Acrylic Sales Co., Ltd. The substrate on which the coating film had been formed was dried with hot air at 140°C for 120 seconds to obtain a substrate with a photo-alignment film. The thickness of the photo-alignment film was 0.3 μm.

[0166] ---------------------------------------------------------------------------------- (Coating liquid PA1 for photo alignment film formation) ---------------------------------------------------------------------------------- 100.00 parts by mass of the following polymer PA-1 5.00 parts by mass of the acid generator PAG-1 shown below 0.005 parts by mass of the following acid generator CPI-110TF Xylene 1220.00 parts by mass Methyl isobutyl ketone 122.00 parts by mass ----------------------------------------------------------------------------------

[0167] Polymer PA-1 [ka]

[0168] Acid generator PAG-1 [ka]

[0169] Acid generator CPI-110F [ka]

[0170] <Forming of photo-alignment film> Referring to JP 2012-116094 A, the substrate with the above-mentioned photo-alignment film was vacuum-molded onto the convex surface of a plano-convex lens (made of optical glass, convex surface curvature radius 100 mm) with a diameter of 40 mm and a focal length of 200 mm. Thereafter, the substrate with the photo-alignment film was peeled off from the lens to obtain a laminate having the substrate and the photo-alignment film with a curved surface portion.

[0171] <Alignment treatment of photo-aligned film> Ultraviolet light generated using an ultra-high pressure mercury lamp was incident on a convex lens with a diameter of 100 mm and a focal length of 300 mm, and the ultraviolet light was concentrated. Next, a wire grid polarizer was placed on the opposite side of the convex lens from the ultra-high pressure mercury lamp, 70 mm from the convex lens, to polarize the ultraviolet light. Furthermore, the photo-alignment film with a curved surface obtained above was placed 150 mm from the convex lens, with the convex side of the curved surface facing the ultra-high pressure mercury lamp and the convex lens, and 10 mJ / cm was applied to the photo-alignment film. 2 The alignment treatment of the photo-alignment film was carried out by exposing it to polarized UV light. By orienting the alignment axis of the photo-alignment film using the above method, a photo-alignment film was obtained that can form an optically absorbing anisotropic layer having multiple regions on the surface of the photo-alignment film with different absorption axis directions (see Figure 3), and when observed from position Z, the angle between the absorption axis direction of polarizer A and the absorption axis direction of polarizer B described below is 90° across the entire region of polarizer B.

[0172] <Preparation of composition for forming optically absorptive anisotropic layer> A composition P1 for forming an optically absorptive anisotropic layer having the following composition was prepared.

[0173] ---------------------------------------------------------------------------------- Composition of optically absorptive anisotropic layer-forming composition P1 ---------------------------------------------------------------------------------- 0.05 parts by weight of the following dichroic substance D-1 0.07 parts by mass of the following dichroic substance D-2 0.12 parts by mass of the following dichroic substance D-3 0.44 parts by mass of the following polymer liquid crystal compound P-1 0.27 parts by mass of the following low-molecular-weight liquid crystal compound M-1 Polymerization initiator IRGACUREOXE-02 (BASF) 0.040 parts by mass 0.005 parts by mass of the following surfactant F-1 Cyclopentanone 48.0 parts by mass Tetrahydrofuran 48.0 parts by mass Benzyl alcohol 3.00 parts by mass ----------------------------------------------------------------------------------

[0174] D-1 [ka]

[0175] D-2 [ka]

[0176] D-3 [ka]

[0177] Polymer liquid crystal compound P-1 [ka]

[0178] Low molecular liquid crystal compound M-1 [ka]

[0179] Surfactant F-1 [ka]

[0180] <Preparation of Polarizer A> A coating film formation process was carried out in which the above-mentioned composition for forming an optically absorbing anisotropic layer was spray-coated onto the surface of the curved photo-alignment film that had been subjected to the above-mentioned alignment treatment using a coater called "rCoater" manufactured by Asahi Sunac Corporation, thereby forming a coating layer P1. Next, as an orientation process, the coating layer P1 was heated at 140°C for 30 seconds, then cooled to room temperature (23°C), and then heated again at 90°C for 60 seconds and cooled again to room temperature. Thereafter, as a curing step, the coating layer P1 was irradiated with light of a central wavelength of 365 nm at an illuminance of 200 mW / cm using an LED lamp. 2 The light absorption anisotropic layer was formed by irradiating the film for 2 seconds under the irradiation conditions of 1. In this way, an absorptive polarizer A was prepared, which included a substrate, a photo-alignment film, and a light-absorption anisotropic layer, and also had a curved surface portion. The thickness of the optically absorptive anisotropic layer of the obtained absorptive polarizer A was 1.6 μm.

[0181] <Fabrication and shaping of λ / 4 plate> A reverse dispersion λ / 4 plate was prepared by curing a liquid crystal composition containing a liquid crystal compound, with reference to JP 2018-010224 A. Next, the prepared λ / 4 plate was transferred to the resin substrate "Technoloy C001" using a UV-curable adhesive. The obtained λ / 4 plate with a resin substrate was vacuum molded according to the method described above in <Molding of photo-alignment film> to obtain a λ / 4 plate having a curved surface shaped along the convex surface of a plano-convex lens with a curvature radius of 100 mm.

[0182] <Forming of reflective linear polarizer> A reflective linear polarizer "APF" manufactured by 3M was vacuum molded according to the method described in <Molding of photo-aligned film> above, to obtain a reflective linear polarizer λ / 4 plate having a shape following the convex surface of a plano-convex lens with a curvature radius of 100 mm.

[0183] [Manufacturing of image display devices] We disassembled the Huawei VR Glass, a virtual reality display device that uses a reciprocating optical system, and removed the lens located on the most visible side and the half mirror located on the next most visible side. After removing the lens, the Huawei VR Glass contained, in order from the visible side, a λ / 4 plate, an absorptive polarizer, and an image display element. Next, the absorptive polarizer A, reflective linear polarizer, and λ / 4 plate prepared by the above-mentioned methods were attached in this order to the convex side of a plano-convex lens with a diameter of 40 mm and a focal length of 200 mm to prepare a laminated lens. The laminated lens thus prepared was used in place of the removed viewing-side lens, and a pre-prepared half mirror (with a curvature radius of 100 mm) was used in place of the removed half mirror. The Huawei VR Glass was then reassembled to produce the virtual reality display device of Example 1. The manufactured virtual reality display device of Example 1 had the configuration shown in Figure 4. That is, in the virtual reality display device of Example 1, the following were arranged in order from the viewing side: absorbing polarizer A, reflective linear polarizer, first λ / 4 plate, half mirror, second λ / 4 plate, absorbing polarizer B, and image display element. The absorbing polarizer A, first λ / 4 plate, reflective linear polarizer, and half mirror all had curved surfaces, with the concave surface facing the viewing side and the convex surface facing the image display element. The second λ / 4 plate and absorbing polarizer B were planar.

[0184] When the above-described method for identifying position Z was tested on the virtual reality display device of Example 1, the existence of position Z that satisfies the specific requirements was confirmed on line L. That is, in the virtual reality display device of Example 1, when the directions of line L and virtual lines L1 to L4 were observed, it was found that there was position Z where the angle between the absorption axis of polarizer A and the absorption axis of polarizer B was 90°. Furthermore, when measured using the above-mentioned measurement method, it was found that in the virtual reality display device of Example 1, when observed from position Z in the directions of line L and virtual lines L1 to L4, the absorption axis of polarizer A and the reflection axis of the reflective linear polarizer were parallel, the angles between the absorption axis of polarizer A and the slow axis of the first λ / 4 plate were each 45°, and the slow axis of the first λ / 4 plate and the slow axis of the second λ / 4 plate were each perpendicular to each other.

[0185] [Comparative Example 1] As Comparative Example 1, a virtual reality display device manufactured by Huawei, "Huawei VR Glass," was used. The lens placed on the most visible side of the virtual reality display device of Comparative Example 1 (the lens removed in Example 1) was a plano-convex lens with a convex surface on the visible side, and an absorptive polarizer, a reflective linear polarizer, and a λ / 4 plate were placed on the flat surface of the plano-convex lens, in that order from the visible side. That is, in the virtual reality display device of Comparative Example 1, a first absorptive polarizer, a reflective linear polarizer, a first λ / 4 plate, a half mirror, a second λ / 4 plate, a second absorptive polarizer, and an image display panel were arranged in this order from the viewing side. Note that each absorptive polarizer, each λ / 4 plate, reflective linear polarizer, and half mirror were all planar and arranged parallel to each other. Furthermore, the absorption axis of each absorptive polarizer was arranged linearly along one in-plane direction.

[0186] When the virtual reality display device of Comparative Example 1 was observed from a distanced position on the convex side of the plano-convex lens, the angle between the absorption axis of the first absorbing polarizer and the absorption axis of the second absorbing polarizer was 90° in the region where the observation position intersected with a perpendicular line dropped from the observation position to the first absorbing polarizer and the second absorbing polarizer. However, when observing in a direction away from the above region from the observation position, the angle between the absorption axis of the first absorbing polarizer at the intersection with a line in the above direction and the absorption axis of the second absorbing polarizer at the intersection with a line in the above direction was not 90°. Furthermore, the above-described method for specifying the position Z was tried for the virtual reality display device of Comparative Example 1, but the existence of the position Z that satisfied the specific requirements could not be confirmed.

[0187] [Ghost Rating] In each of the virtual reality display devices thus fabricated, a black and white checkered pattern was displayed on the image display element, and the ghosts observed from the viewing side were visually evaluated. As a result, in the virtual reality display device of Comparative Example 1, the image of the white display area was seen as a ghost in part of the black display area of ​​the checkered pattern, and the checkered pattern was not clear. The influence of the ghost was particularly noticeable when the display image in the area near the periphery was viewed. In contrast, in the virtual reality display device of Example 1, no ghosts caused by stray light were visible throughout the entire lens area, and the checkered pattern was clearly displayed.In particular, in the virtual reality display device of Comparative Example 1, no ghosts were visible in the displayed image near the periphery, where the effect of ghosts was particularly pronounced, just like in the center of the displayed image. [Explanation of symbols]

[0188] 10 Optical elements 20, 22, 30 Image display device 24 cabinets 31,34 Absorptive polarizer 32 Reflective polarizer 33,300 Half mirror 35,500 image display elements 100 Polarizer A 200 reflective linear polarizer 202 Reflective circular polarizer 400 Polarizer B 600 First λ / 4 plate 700 Second λ / 4 plate S,V ray

Claims

1. A method for manufacturing an absorptive polarizer having a plurality of regions whose absorption axis directions are different from each other and having a curved surface portion, comprising: forming a layer of a composition for forming a photo-alignment film containing a photo-alignment agent on a surface of a resin substrate; a step of irradiating the layer with linearly polarized ultraviolet light through a lens having a convex surface to align the photo-alignment agent, thereby forming an alignment film; applying a composition containing a liquid crystal compound and a dichroic material to the surface of the alignment film; the alignment film has a curved surface portion and a plurality of regions in which the directions of the alignment regulating force are different from each other; the step of forming a layer of the composition for forming a photo-alignment film on the surface of a resin substrate includes a step of applying the composition for forming a photo-alignment film on the surface of a resin substrate molded into a curved surface to form a layer of the composition for forming a photo-alignment film having a curved portion, or includes a step of applying the composition for forming a photo-alignment film on the surface of a flat resin substrate to form a coating film, and a step of molding the resin substrate and the coating film into a curved surface to form a layer of the composition for forming a photo-alignment film having a curved portion, a manufacturing method in which, in the step of forming the alignment film, a light source of ultraviolet light, the lens having a convex surface, and the layer of the composition for forming a photoalignment film having the curved portion are arranged so that the convex side of the curved portion of the layer faces the lens having the convex surface, and so that ultraviolet light is irradiated onto the layer through the lens having the convex surface.

2. The method for producing a polarizer according to claim 1 , wherein the step of applying the composition is a step of spray-applying the composition onto the surface of the alignment film.

3. 2. The method for producing a polarizer according to claim 1, wherein the step of forming a layer of the composition for forming a photo-alignment film on the surface of a resin substrate includes a step of applying the composition for forming a photo-alignment film to the surface of a planar resin substrate to form a coating film, and a step of shaping the resin substrate and the coating film into a curved shape.

4. A method for manufacturing an optical element including a polarizer A and an absorptive polarizer B, comprising the steps of: A method for manufacturing an optical element, comprising the steps of: manufacturing the optical element by using, as the polarizer A, a polarizer manufactured by the method for manufacturing a polarizer according to any one of claims 1 to 3.

5. A method for manufacturing an image display device including an optical element and an image display element, comprising: A method for manufacturing an image display device, comprising the steps of: manufacturing the image display device by using, as the optical element, an optical element manufactured by the method for manufacturing an optical element according to claim 4 .

6. 6. The method for manufacturing an image display device according to claim 5, wherein the image display device has, between the polarizer A and the polarizer B, a reflective linear polarizer, a first λ / 4 plate, a half mirror, and a second λ / 4 plate, in this order from the polarizer A side.

7. 6. The method for manufacturing an image display device according to claim 5, wherein the image display device has, between the polarizer A and the polarizer B, a first λ / 4 plate, a reflective circular polarizer, a half mirror, and a second λ / 4 plate, in this order from the polarizer A side.

8. The method for manufacturing an image display device according to claim 7 , wherein the reflective circular polarizer has a cholesteric liquid crystal layer.

9. 9. The method for manufacturing an image display device according to claim 5, wherein the polarizer B is laminated on the image display element.

10. A method for manufacturing a virtual reality display device including an image display device, A method for manufacturing a virtual reality display device, comprising the steps of: manufacturing the virtual reality display device using the image display device according to any one of claims 5 to 9 as the image display device.

11. A method of manufacturing an electronic viewfinder equipped with an image display device, comprising: A method for manufacturing an electronic finder, comprising the steps of: manufacturing the electronic finder using the image display device according to any one of claims 5 to 9 as the image display device.

Images