Abstract: An object is to provide an optical element in which a wavelength dependence of refraction of transmitted light is small, and a light guide element including the optical element.

Abstract: An object of the present invention is to provide a light irradiation device which is thin and is capable of projecting an optical pattern, and a sensor which uses the light irradiation device. The object is achieved by a light irradiation device including a light emitting element which includes a plurality of light emitting units in a plane; and a liquid crystal optical element, in which the liquid crystal optical element has an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound, the optically anisotropic layer has a liquid crystal alignment pattern in which orientation of an optical axis derived from the liquid crystal compound continuously changes rotationally along at least one in-plane direction and has regions with different lengths of periods in a case where a length over which the orientation of the optical axis derived from the liquid crystal compound rotates by 180° in the plane is denoted by a single period.

Abstract: An object of the present invention is to provide: an optical element in which incident light can be transmitted or reflected at an angle in the predetermined direction and the wavelength dependence of the amount of transmitted light or reflected light is small; and an optical element including the optical element. The optical element according to the present invention comprises: an optically-anisotropic layer that is formed using a composition including a liquid crystal compound and an infrared absorbing colorant, 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 changes while continuously rotating in at least one in-plane direction, and an absorption of the infrared absorbing colorant in a wavelength range of 700 to 2000 nm in a minor axis direction is higher than an absorption of the infrared absorbing colorant in a wavelength range of 700 to 2000 nm in a major axis direction.

Abstract: Provided is an optical element with which a high diffraction efficiency can be obtained with a simple configuration. The optical element includes: an optically-anisotropic layer that is formed using 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 changes while continuously rotating in at least one in-plane direction, and the optically-anisotropic layer has a region in which an alignment direction of a liquid crystal compound in at least one of upper and lower interfaces has a pre-tilt angle with respect to the interface.

Abstract: Provided is an image display device including an image display unit which includes a display area in which a plurality of pixels is arranged, and a non-display area provided at a periphery of the display area, a light guide unit which has one surface disposed so as to face at least an edge of the display area of the image display unit on a viewing side and another surface that is disposed at an opposite side of the light guide from the one surface and is provided at a position shifted further toward the non-display area than the one surface, and a diffraction element which is disposed between the image display unit and the light guide unit and diffracts light from the display area toward the side of the non-display area adjacent to the edge.

Abstract: Provided is an optical element in which the amount of light having a wavelength causing a disturbance noise can be reduced and light can be diffracted with a high diffraction efficiency. The optical element comprising: an optically-anisotropic layer that is formed using a composition including a liquid crystal compound and a dichroic colorant, 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 changes while continuously rotating in at least one in-plane direction.

Abstract: Provided is an optical element in which transmission of incident light with an angle in a predetermined direction is allowed and the brightness of transmitted light is high. The optical element is formed using a 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 rotates in one direction; and the optically-anisotropic layer has regions in which the optical axis is twisted in a thickness direction of the optically-anisotropic layer and rotates, the regions having different magnitudes of twist angles of the rotation in a plane.

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.

Abstract: Provided is a display device capable of switching between a wide viewing angle and a narrow viewing angle with a simple configuration and simple control. The problem is solved by providing a display element and an optical switching element which is disposed on a visible side of the display element, in which the optical switching element has a light guiding plate and a light source for causing light to be incident on an end surface of the light guiding plate, and 80% or more of the light emitted from the light guiding plate when the light source is turned on is emitted to a region at an angle of 30° or more with respect to a normal line of the light guiding plate on a surface on the opposite side of the display element.

Abstract: An object of the present invention is to provide an optical device that can accomplish both the effect of preventing external light reflection and the improvement of utilization efficiency of light emitted from an organic electroluminescent element. The object is achieved by an optical device having an organic electroluminescent substrate, a circularly polarized light-separating layer separating light into right-handed circularly polarized light and left-handed circularly polarized light, a ?/4 plate, and a polarizer, wherein the circularly polarized light-separating layer has a liquid crystal alignment pattern in which a liquid crystal compound is twisted and aligned along a helical axis extending in a thickness direction and the direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in one direction in the plane.

Abstract: A display device includes an image display panel, and a viewing angle switching element includes a first linear polarizer, an optically anisotropic layer, a viewing angle control cell, and a second linear polarizer, in which an angle formed between transmission axes of the first linear polarizer and the second linear polarizer is 45°, the optically anisotropic layer has a function of changing an azimuth of a polarization axis of linearly polarized light emitted from the first linear polarizer and causing the light to be emitted toward the viewing angle control cell, the viewing angle control cell is formed of a vertically aligned liquid crystal cell in which vertically aligned liquid crystals are tilted in one direction by voltage application, and an angle formed between a tilt azimuth of the vertically aligned liquid crystal of the viewing angle control cell and the transmission axis of the second linear polarizer is 45°.

Abstract: Provided is an optical element that reflects light using a cholesteric liquid crystal layer, in which the amount of light reflected is large. 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, at least one combination of two cholesteric liquid crystal layers having the same turning direction of circularly polarized light to be reflected and including an overlapping portion in at least a part of selective reflection wavelength ranges, and a ?/2 plate is provided between two cholesteric liquid crystal layers forming the combination of the cholesteric liquid crystal layers.

Abstract: An object of the present invention is to provide an optical device that can accomplish both the effect of preventing external light reflection and the improvement of utilization efficiency of light emitted from an organic electroluminescent element. The object is achieved by an optical device having an organic electroluminescent substrate, a circularly polarized light-separating layer that has a liquid crystal alignment pattern, in which the direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in one direction in a plane, and separates light into right-handed circularly polarized light and left-handed circularly polarized light, a patterned retardation layer that converts circularly polarized light into linearly polarized light and has a plurality of regions among which the direction of a slow axis varies in the same plane, and a polarizer.

Abstract: An object is to provide an optical element in which a wavelength dependence of refraction of transmitted light is small, and a light guide element including the optical element.

Abstract: An object is to provide an optical element in which a wavelength dependence of reflection is small, a light guide element including the optical element, and an image display device including the light guide element. The optical element includes a plurality of cholesteric liquid crystal layers having different selective reflection center wavelengths, 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 length over which the optical axis rotates by 180° in the in-plane direction is set as a single period, a permutation of lengths of selective reflection center wavelengths and a permutation of lengths of the single periods match each other in the cholesteric liquid crystal layers.

Abstract: A display device includes an image display panel, and a viewing angle switching element includes a first linear polarizer, an optically anisotropic layer, a viewing angle control cell, and a second linear polarizer, in which an angle formed between transmission axes of the first linear polarizer and the second linear polarizer is 45°, the optically anisotropic layer has a function of changing an azimuth of a polarization axis of linearly polarized light emitted from the first linear polarizer and causing the light to be emitted toward the viewing angle control cell, the viewing angle control cell is formed of a vertically aligned liquid crystal cell in which vertically aligned liquid crystals are tilted in one direction by voltage application, and an angle formed between a tilt azimuth of the vertically aligned liquid crystal of the viewing angle control cell and the transmission axis of the second linear polarizer is 45°.

Abstract: The optical element is an optical element comprising a first optically anisotropic layer which is a cured layer of a liquid crystal composition containing a first disk-like liquid crystal compound, in which the optical element has a liquid crystal alignment pattern in which an optical axis of the first disk-like liquid crystal compound is parallel to a surface of the first optically anisotropic layer, the first optically anisotropic layer is disposed along at least one direction in a plane of the first optically anisotropic layer, and orientation of the optical axis of the first disk-like liquid crystal compound rotationally changes continuously, and the orientation of the optical axis rotates by 180° with a period of 0.5?m to 5?m.

Abstract: A display device includes an image display panel, and a viewing angle switching element, in which the viewing angle switching element includes first and second linear polarizers arranged to face each other, and a viewing angle control cell and an optical compensation sheet arranged in a laminated manner between the first and second linear polarizers, the viewing angle control cell includes a single domain vertical alignment liquid crystal cell, an angle formed between an in-plane fast axis of the optical compensation sheet and the absorption axis or the reflection axis of the first linear polarizer is 30° to 60°, and a pretilt azimuth of the vertically aligned liquid crystal of the viewing angle control cell is at an angle of 30° to 60° from the absorption axis or the reflection axis of the first linear polarizer.

Abstract: The planar lighting device includes: a light source; and a brightness homogenizing member that has a laminate structure including high refractive index layers and low refractive index layers, and a light incidence portion that allows light emitted from each of the plurality of point light sources to be incident into the high refractive index layers is provided at a position of the laminate structure facing the point light source. The light incidence portion is formed of a hollow portion that is provided across the two or more high refractive index layers included in the laminate structure to penetrate at least one high refractive index layer and has a function of allowing the light to be incident into the high refractive index layers, and each of the high refractive index layers includes a light extraction mechanism that is provided at a position spaced apart from the light incidence portion.

Abstract: A phase difference film is formed by using a liquid crystal compound and that indicates an Nz factor of more than 0 and less than 1, an optical film with same, and a display device. The phase difference film is formed by using a composition including a polymerizable liquid crystal compound having a mesogen group, where an order parameter of the mesogen group in an in-plane slow axis direction of the phase difference film is set as Sx, an order parameter of the mesogen group in a direction orthogonal to the in-plane slow axis direction in a plane is set as Sy, and an order parameter of the mesogen group in a thickness direction of the phase difference film is set as Sz, in a case where the mesogen group has a rod or a disc shape, differing Expressions are satisfied.