Abstract: Provided are a backlight unit and a liquid crystal display device including the backlight unit, the backlight unit being capable of switching between viewing angles in the liquid crystal display device and having a configuration in which the brightness values of emitted light on the “+” side and the “?” side at a polar angle with respect to the normal line are symmetric to each other.

Abstract: Provided are a cholesteric liquid crystal layer having a high diffraction efficiency, a method of forming the same, and a laminate, a light guide element, and an image display device that include the cholesteric liquid crystal layer. The cholesteric liquid crystal layer is obtained by immobilizing a cholesteric liquid crystalline phase, in which the cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, in a cross-section observed with a SEM, bright portions and dark portions are tilted, in a case where a tilt angle of a direction in which an in-plane retardation is minimum with respect to a normal line in a slow axis plane or a fast axis plane is represented by ?2, an absolute value of an optical axis tilt angle ? represented by “sin ?2=n·sin ? (n represents an average refractive index of the cholesteric liquid crystal layer)” is 5° or more.

Abstract: An object of the present invention is to provide an optical element capable of widening a field of view of an AR glass or the like; and an image display device using the optical element. The object is accomplished with an optical element including a light guide plate; a switching ?/2 plate capable of switching a phase difference between zero and ?/2; and a first optically anisotropic layer that is arranged between the light guide plate and the switching ?/2 plate, is formed using a composition including a liquid crystal compound, and has a liquid crystal alignment pattern in which an orientation of an optical axis derived from the liquid crystal compound changes while continuously rotating along at least one in-plane direction of the first optically anisotropic layer.

Abstract: Provided is a sensor having a high SN ratio. The sensor includes a light source, a band pass filter; and a light-receiving element, in which the band pass filter includes a cholesteric liquid crystal layer that is a layer obtained by immobilizing a cholesteric liquid crystalline phase, the cholesteric liquid crystal layer has a region where a refractive index nx in an in-plane slow axis direction and a refractive index ny in an in-plane fast axis direction satisfy nx>ny, and in a case where a selective reflection wavelength of the cholesteric liquid crystal layer is represented by ?, the cholesteric liquid crystal layer has a second selective reflection peak at a wavelength ?/2 and a half-width of the second selective reflection peak at ?/2 is 30 nm or less.

Abstract: Provided are a cholesteric liquid crystal layer that diffracts specific circularly polarized light in a specific wavelength range by transmission, and a method of forming the cholesteric liquid crystal layer. The cholesteric liquid crystal layer is obtained by immobilizing a cholesteric liquid crystalline phase, in which the cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, in a cross-section of the cholesteric liquid crystal layer observed with a scanning electron microscope, bright portions and dark portions derived from the cholesteric liquid crystalline phase are tilted at 80° or more with respect to a main surface of the cholesteric liquid crystal layer.

Abstract: Provided are an optical element with which reflected light in a narrower wavelength range can be obtained and a wavelength selective filter and a sensor including the same optical element. The optical element includes 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 a liquid crystal compound changes while continuously rotating in at least one in-plane direction, and the cholesteric liquid crystal layer has a region where a refractive index nx in an in-plane slow axis direction and a refractive index ny in an in-plane fast axis direction satisfy nx>ny.

Abstract: Provided is a sensor having a high SN ratio. The sensor includes a light source, a band pass filter, and a light-receiving element, in which the band pass filter includes two cholesteric liquid crystal layers and a discontinuous layer disposed between the two cholesteric liquid crystal layers, in the two cholesteric liquid crystal layers, helical twisted directions and helical pitches are the same, and in a case where the discontinuous layer is a layer other than a cholesteric liquid crystal layer and a wavelength having a lowest reflectivity in a selective reflection wavelength range of the band pass filter is represented by ?m [nm], a thickness [nm] is in a range of “30×(?m/550) to 150×(?m/550)”.

Abstract: Provided are a liquid crystal diffraction element that diffracts incident light while allowing transmission of the incident light and has wavelength selectivity, and a laminated diffraction element.

Abstract: Provided are a light guide element and an image display apparatus capable of suppressing the occurrence of multiple images.

Abstract: Provided is a small-sized light irradiating device having a simple configuration that projects an optical pattern. The light irradiating device includes a light source and a liquid crystal hologram element, in which the liquid crystal hologram element diffracts transmitted light in a plurality of different directions, the liquid crystal hologram element includes a liquid crystal hologram layer, the liquid crystal hologram layer is a layer that consists of a computer generated hologram and is formed of a composition including a liquid crystal compound, and the liquid crystal hologram layer further includes a plurality of regions in which directions of optical axes derived from the liquid crystal compound are different from each other.

Abstract: Provided are an optical element, a light guide element, and an image display element in which the occurrence of sidelobe is suppressed. The optical element includes a cholesteric liquid crystal layer that is obtained by immobilizing a cholesteric liquid crystalline phase, in which the cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, and in a case where a birefringence in a thickness region of 80% as a center portion with respect to a thickness of the cholesteric liquid crystal layer is represented by ?n1, a birefringence in a thickness region of 10% from one surface of the cholesteric liquid crystal layer is represented by ?n2, and a birefringence in a thickness region of 10% from another surface of the cholesteric liquid crystal layer is represented by ?n3, at least one of ?n2 or ?n3 is less than ?n1.

Abstract: Provided are a light guide element in which incidence light can be emitted with high use efficiency and a wide FOV can be obtained for use in AR glasses, and an image display device and a sensing apparatus that include the light guide element. The light guide element includes a light guide plate and first to third diffraction elements, in which the first diffraction element diffracts incidence light in two or more different directions to be incident into the light guide plate, the second diffraction element includes a plurality of diffraction elements that diffract the light to the third diffraction element, the third diffraction element emits the light from the light guide plate, and at least one of the first diffraction element or the third diffraction element 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.

Abstract: Provided are a liquid crystal diffraction element that can make the brightness of light emitted from a light guide plate uniform and a light guide element. The liquid crystal diffraction element includes: an optically-anisotropic layer that is formed of a composition including a liquid crystal compound, in which the optically-anisotropic layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound continuously rotates in at least one in-plane direction, and a diffraction efficiency of the optically-anisotropic layer increases from one side to another side in the one in-plane direction.

Abstract: An object of the present invention is to provide an optical element capable of widening a field of view of an AR glass or the like; and an image display device using the optical element. The object is accomplished with an optical element including a light guide plate; a switching ?/2 plate capable of switching a phase difference between zero and ?/2; and a first optically anisotropic layer that is arranged between the light guide plate and the switching ?/2 plate, is formed using a composition including a liquid crystal compound, and has a liquid crystal alignment pattern in which an orientation of an optical axis derived from the liquid crystal compound changes while continuously rotating along at least one in-plane direction of the first optically anisotropic layer.

Abstract: Provided are an optical laminate in which a large diffraction angle can be obtained, a light guide element, and an AR display device.

Abstract: Provided are an optical laminate in which a large diffraction angle can be obtained, a light guide element, and an AR display device.

Abstract: Provided are an optical laminate that can refract incident light with a high use efficiency to be incident into a light guide plate or the like, and a light guide element and an image display device including the optical laminate. The optical laminate includes first and second cholesteric liquid crystal layers that have a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, in which in the first and second cholesteric liquid crystal layers, helical pitches in a cholesteric liquid crystalline phase are different from each other, turning directions of circularly polarized light to be reflected are the same, and rotation directions of the direction of the optical axis that continuously rotates in at least one in-plane direction in the liquid crystal alignment pattern are the same.

Abstract: Provided are an optical element, including a plurality of optically anisotropic layers, each of which has an in-plane alignment pattern in which orientations of optical axes derived from a liquid crystal compound change continuously and rotationally along at least one in-plane direction, in a thickness direction, in which the optically anisotropic layers each have regions where lengths over which the orientations of the optical axes rotate by 180° in the one direction are different from each other, and at least one of the plurality of optically anisotropic layers is an inclined optically anisotropic layer having a region where a plurality of pairs of bright lines and dark lines in a cross-sectional image are present and the pairs of the bright lines and the dark lines are inclined at inclination angles which are different from each other with respect to a normal line of an interface of the optically anisotropic layer.

Abstract: Provided are an optical element including a first optically-anisotropic layer consisting of a cured layer of a composition including a first liquid crystal compound, in which the first optically-anisotropic layer has 0.24 or more of a refractive index anisotropy ?n550 which is measured with light having a wavelength of 550 nm, the first optically-anisotropic layer has a first liquid crystal alignment pattern in which a direction of an optical axis derived from the first liquid crystal compound continuously changes rotationally in at least one in-plane direction, and in the first liquid crystal alignment pattern, in a case where a length ? over which the direction of the optical axis rotates 180° in a plane is defined as a single period, the length ? of the single period is 1.6 ?m or less; a method for forming a photo-alignment pattern; and a method for manufacturing an optical element.

Abstract: Provided are an optical element that can make the brightness of light emitted from a light guide plate uniform, a light guide element, and an image display device. The optical element includes a patterned cholesteric liquid crystal layer that is obtained by immobilizing a cholesteric liquid crystalline phase, in which the patterned cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, and the patterned cholesteric liquid crystal layer has regions having different pitches of helical structures in a plane.