Abstract: A light absorption anisotropic layer which has high contrast and can suppress hue change of an image reflected by surroundings relative to an original image when used in a viewing angle control system, an optical film using the light absorption anisotropic layer, a viewing angle control system, and an image display device. The light absorption anisotropic layer is formed of a liquid crystal composition containing a liquid crystalline compound, a dichroic substance, and an alignment agent. The liquid crystalline compound is in a liquid crystal state of a smectic phase, a content of the dichroic substance is 5.0% by mass or more with respect to a total solid content mass of the liquid crystal composition, and an angle ? between a transmittance central axis of the light absorption anisotropic layer and a normal direction of a surface of the light absorption anisotropic layer is between 0° and 45°.

Abstract: An optical film that, when being used in an image display device, it is possible to suppress a change in redness with respect to an original image in images reflected in surroundings, a manufacturing method of a light absorption anisotropic layer, and an image display device. The optical film includes a light absorption anisotropic layer which contains a liquid crystalline compound and a dichroic substance, in which an angle ? between a transmittance central axis of the light absorption anisotropic layer and a normal direction of a surface of the light absorption anisotropic layer is 0° or more and 45° or less, and a haze value of the optical film is more than 1% and 20% or less.

Abstract: A light guide element includes: a light guide plate; and a diffraction element that is disposed on a main surface of the light guide plate, in which the diffraction element includes a liquid crystal layer that is formed of a liquid crystal composition including a liquid crystal compound and has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction, a refractive index of the light guide plate is 1.70 or higher, and in a case where the refractive index of the light guide plate is represented by nd and a refractive index of the liquid crystal layer is represented by nk, nk?nd?0 is satisfied.

Abstract: Provided are an optical filter, an optical device, and a head-mounted display which have a high light transmittance in a front direction and a wide real field of view. The optical filter includes a first anisotropic absorption layer, a first retardation layer, and a second anisotropic absorption layer in this order, each of the first anisotropic absorption layer and the second anisotropic absorption layer contains a dichroic colorant, an absorption axis of the dichroic colorant is perpendicular to a main surface, and the first retardation layer has polar angle dependence of retardation that has asymmetry about a normal direction with respect to incident light hitting at least one incident surface including a normal of a layer surface of the first retardation layer.

Abstract: A light guide element includes: a light guide plate; and a diffraction element that is disposed on a main surface of the light guide plate, in which the diffraction element includes a liquid crystal layer that is formed of a liquid crystal composition including a liquid crystal compound and has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction, a refractive index of the light guide plate is 1.70 or higher, and in a case where the refractive index of the light guide plate is represented by nd and a refractive index of the liquid crystal layer is represented by nk, nk?nd?0 is satisfied.

Abstract: The present invention provides a polarizing element which has an excellent antireflection function as being applied to an image display device; and a circularly polarizing plate and an image display device, each of which has a polarizing element. The polarizing element has an alignment film and an anisotropic light-absorbing film formed using a dichroic substance, in which a degree S of alignment of the anisotropic light-absorbing film is 0.92 or more, an average refractive index nave at a wavelength of 400 to 700 nm of the alignment film is 1.55 or more and less than 1.78, an in-plane refractive index anisotropy ?n at a wavelength of 550 nm of the alignment film is less than 0.10.

Abstract: Provided is a viewing angle control polarizing plate that has asymmetric transmission characteristics, does not cause moire even in a case of being used in combination with a high-definition image display device, and is capable of easily following a curved surface and a viewing angle control system with high productivity. The viewing angle control system includes at least a first polarizer and an optically anisotropic layer, in which an absorption axis of the first polarizer forms an angle of 45° or greater with respect to an in-plane direction, and a main axis of a refractive index of the optically anisotropic layer is tilted in the in-plane direction.

Abstract: Provided is a light absorption anisotropic layer including a dichroic substance, in which a transmittance as viewed from a front direction is high and a transmittance as viewed from an oblique direction can be lowered, a laminate, an optical film, an image display device, and a backlight module. The light absorption anisotropic layer includes a liquid crystalline compound and at least one dichroic substance, in which the dichroic substance is aligned perpendicular to the film surface, and an alignment degree of the light absorption anisotropic layer at a wavelength of 550 nm is 0.95 or more.

Abstract: An optical element includes a light guide plate, an incidence portion, and an emission portion, in which the incidence/emission portion includes an ?1 diffraction element having a diffraction period ?1, an ?2 diffraction element having a diffraction period ?2, and an ?3 diffraction element having a diffraction period ?3, “?1:?2:?3 = 1: 1/?2± 0.015: ½ ± 0.015” is satisfied, an angle between periodic directions of the ?1 diffraction element and the ?2 diffraction element and an angle between periodic directions of the ?2 diffraction element and the ?3 diffraction element is 45° or 135° (± 0.5°), and an angle between the periodic directions of the ?2 diffraction elements in the incidence portion and the emission portion is any one of 0°, 90°, 180°, or 270° (± 0.5°).

Abstract: Provided is an optical element that can display a clear image having no blurriness in AR glasses or the like. The optical element includes: a substrate; and a laminate that is provided on the substrate and where a plurality of liquid crystal layers obtained by aligning a liquid crystal compound are laminated, in which the liquid crystal layers have a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction, and in at least one of the liquid crystal layers, an arithmetic mean value of differences between maximum film thicknesses and minimum film thicknesses obtained by observing 10 cross-sections with a scanning electron microscope is 0.1 ?m or less.

Abstract: An optical element comprising: a cholesteric liquid crystal layer obtained by cholesteric alignment of a liquid crystal compound, in which the cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction, a helical pitch of a helical axis direction in the cholesteric alignment gradually changes in a thickness direction of the cholesteric liquid crystal layer, and the cholesteric liquid crystal layer has a peak of reflection at each of a first wavelength ? and a second wavelength ?/2.

Abstract: Provided is an optical laminate, an image display device, and a glass composite which are capable of sufficiently shielding light emitted in a direction oblique to a normal direction of a film without occurrence of moire even in a case of being used in a combination with a high-definition image display device. The optical laminate includes, in order, at least a first light absorption anisotropic layer, a refractive index anisotropic layer formed of a one or more layers that contain a liquid crystal compound having a twisted structure, and a second light absorption anisotropic layer, in which the first light absorption anisotropic layer and the second light absorption anisotropic layer contain an anisotropic absorbing material and each have an absorption axis that is aligned at an angle of 60° to 90° with respect to a film surface.

Abstract: A light guide element includes: a light guide plate; and a diffraction element that is disposed on a main surface of the light guide plate, in which the diffraction element includes a liquid crystal layer that is formed of a liquid crystal composition including a liquid crystal compound and has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction, a refractive index of the light guide plate is 1.70 or higher, and in a case where the refractive index of the light guide plate is represented by nd and a refractive index of the liquid crystal layer is represented by nk, nk?nd?0 is satisfied.

Abstract: An optical element includes a light guide plate, an incidence portion, and an emission portion, in which each of the incidence portion and the emission portion includes diffraction portions, the diffraction portion includes diffraction elements, the diffraction element includes a liquid crystal diffraction layer in which a direction of an optical axis of a liquid crystal compound changes while continuously rotating in one in-plane direction, and in a case where the direction in which the direction of the optical axis changes is set as an in-plane rotation direction and a length over which the optical axis rotates by 180° is set as an in-plane period, in-plane rotation directions of liquid crystal diffraction layers of incidence diffraction elements in at least two of a plurality of the incidence diffraction portions are different from each other.

Abstract: A viewing angle control system is used in combination with a high-definition image display device and sufficiently shields light emitted in a direction oblique to a normal direction of a film. The viewing angle control system includes at least a first polarizer, a retardation layer, and a second polarizer in this order, where an absorption axis of the first polarizer forms an angle of 45° or greater with respect to a surface, the retardation layer satisfies Expression (1): an in-plane retardation Re of the retardation layer satisfies an expression of 80 nm<Re<250 nm, and Expression (2): in a case of Nz=Rth/Re+0.5, an expression of 1.5<Nz<6 or ?5<Nz<?0.5 is satisfied, where Rth represents a retardation of the retardation layer in a thickness direction, and the second polarizer has an absorption axis in an in-plane direction.

Abstract: Provided is a viewing angle control polarizing plate that has asymmetric transmission characteristics, does not cause moire even in a case of being used in combination with a high-definition image display device, and is capable of easily following a curved surface and a viewing angle control system with high productivity. The viewing angle control system includes at least a first polarizer and an optically anisotropic layer, in which an absorption axis of the first polarizer forms an angle of 45° or greater with respect to an in-plane direction, and a main axis of a refractive index of the optically anisotropic layer is tilted in the in-plane direction.

Abstract: An object of the present invention is to provide a laminate in which the coloring of reflected light is reduced. The laminate includes an optical film having a light absorption anisotropic film formed using a composition including a dichroic substance and having a transmittance of more than 50%, a ?/4 plate, and a metal electrode in this order, in which in a case where a degree (%) of polarization at a wavelength of ? of the optical film is defined as P(?) and a reflectance (%) at the wavelength of ? of the metal electrode is defined as R(?), a ratio of a minimum value of R/P to a maximum value of R/P at wavelengths of 450 nm, 550 nm, and 650 nm is more than 85%.

Abstract: Provided is a light absorption anisotropic layer including a dichroic substance, in which a transmittance as viewed from a front direction is high and a transmittance as viewed from an oblique direction can be lowered, a laminate, an optical film, an image display device, and a backlight module. The light absorption anisotropic layer includes a liquid crystalline compound and at least one dichroic substance, in which the dichroic substance is aligned perpendicular to the film surface, and an alignment degree of the light absorption anisotropic layer at a wavelength of 550 nm is 0.95 or more.

Abstract: The present invention provides a polarizing element which has an excellent antireflection function as being applied to an image display device; and a circularly polarizing plate and an image display device, each of which has a polarizing element. The polarizing element has an alignment film and an anisotropic light-absorbing film formed using a dichroic substance, in which a degree S of alignment of the anisotropic light-absorbing film is 0.92 or more, an average refractive index nave at a wavelength of 400 to 700 nm of the alignment film is 1.55 or more and less than 1.78, an in-plane refractive index anisotropy ?n at a wavelength of 550 nm of the alignment film is less than 0.10.

Abstract: An object of the present invention is to provide a laminate including a light absorption anisotropic layer, in which a decrease in a degree of polarization is suppressed even in a case where the laminate is simultaneously stretched in a plurality of directions, and an optical device and a display device, each using the laminate. The laminate of an embodiment of the present invention is a laminate having at least a resin substrate and a light absorption anisotropic layer, in which a tan ? peak temperature of the resin substrate is 170° C. or lower, the light absorption anisotropic layer includes a liquid crystalline compound and a dichroic substance, and an alignment degree of the dichroic substance is 0.95 or more.