Abstract: Provided are an optical element including a single-layer cholesteric liquid crystal layer capable of reflecting red, green, and blue light components, and a light guide element and an AR display device each including the optical element. The optical element includes a cholesteric liquid crystal layer containing a polymer of a polymerizable liquid crystal compound and a chiral agent. The cholesteric liquid crystal layer includes, within a plane, a first reflective region having a reflectance peak that falls within a wavelength range of 400 to 550 nm, and a second reflective region having a reflectance peak that is different from the reflectance peak of the first reflective region and falls within a wavelength range of 550 to 700 nm. The cholesteric liquid crystal layer has a smaller thickness in the first reflective region than in the second reflective region.

Abstract: An optical element is provided that includes: a cholesteric liquid crystal layer including a stack of a first cholesteric liquid crystal layer and a second cholesteric liquid crystal layer. The first and second cholesteric liquid crystal layers each contain a polymer of a polymerizable liquid crystal compound and a chiral agent. The first cholesteric liquid crystal layer has a shorter helical pitch in the first region than in the second region and the second cholesteric liquid crystal layer having a longer helical pitch in the first region than in the second region. The first region is closer to a first end portion than to a central portion in an in-plane first direction, and the second region is closer to a second end portion than to the central portion in the first direction.

Abstract: The optical element includes, in the following order: a first polarizer; a first retardation layer containing first anisotropic molecules; a second polarizer; a second retardation layer containing second anisotropic molecules; and a third polarizer. In a plan view, absorption or reflection axes of the first, second, and third polarizers are parallel. In a plan view, slow axes of the first and second retardation layers are parallel. The absorption or reflection axis of the first polarizer is perpendicular to the slow axis of the first retardation layer. A tilt angle of the first anisotropic molecules is constant in a thickness direction of the first retardation layer. A tilt angle of the second anisotropic molecules is constant in a thickness direction of the second retardation layer. In a plan view, the alignment azimuth of the first anisotropic molecules and the alignment azimuth of the second anisotropic molecules are oriented in opposite directions.

Abstract: Provided are a photomask that has high light resistance and a fine structure and that can be easily produced, and a photoalignment film and a diffractive element produced using the photomask. The photomask of the present invention includes a supporting substrate and a structural birefringence layer arranged on the supporting substrate. The structural birefringence layer has a structure in which, in a plan view, repeating unit structures are periodically arranged. The repeating unit structures each have a structure in which, in a plan view, optical unit structures with slow axes at different azimuthal angles are arranged along an arrangement direction of the repeating unit structures. The optical unit structures each have a structure in which regions with different refractive indices are alternately arranged. The slow axes of the optical unit structures are each not perpendicular to the arrangement direction in a plan view.

Abstract: Provided is a liquid crystal display device in which light leakage during black display is reduced or prevented. The liquid crystal display device includes, in order, a backlight, a first polarizer, a first substrate which exhibits birefringence in a direction parallel to a direction of stress, a liquid crystal layer, a second substrate which exhibits birefringence in a direction parallel to a direction of stress, and a second polarizer. The liquid crystal display device includes, on at least one of a first polarizer side relative to the first substrate or a second polarizer side relative to the second substrate, at least one laminate of a bonding layer with a storage modulus at 25° C. of 0.10 MPa or more and a film that exhibits birefringence in a direction vertical to a direction of stress.

Abstract: Provided are an optical element that has a high diffraction efficiency and can reduce or prevent haze, and a method for producing the optical element. The optical element of the present invention includes an alignment film and an optically anisotropic layer provided on the alignment film and containing anisotropic molecules. The alignment film includes first to N-th alignment treatment regions arranged in order from a central portion to an end portion of the alignment film in a plan view. The first to N-th alignment treatment regions respectively include first to N-th protrusions which protrude toward the optically anisotropic layer and respectively extend in first to N-th directions. The first to (N?1)th directions are not parallel to one another. The N-th direction is parallel to the first direction. N is an integer of 3 or greater.

Abstract: An optical element includes a first polarizer, a first retardation layer including first anisotropic molecules, a second retardation layer including second anisotropic molecules, a second polarizer, a third retardation layer including third anisotropic molecules, a fourth retardation layer including fourth anisotropic molecules, and a third polarizer. Tilt angles of the first anisotropic molecules become larger from the first polarizer side of the first retardation layer toward the second retardation layer. Tilt angles of the second anisotropic molecules become larger from the second polarizer side of the second retardation layer toward the first retardation layer. Tilt angles of the third anisotropic molecules become smaller from the second polarizer side of the third retardation layer toward the fourth retardation layer. Tilt angles of the fourth anisotropic molecules become smaller from the third polarizer side of the fourth retardation layer toward the third retardation layer.

Abstract: An optical element includes a first polarizer, a first retardation layer including first anisotropic molecules, a negative C plate, a second retardation layer including second anisotropic molecules, a second polarizer, a third retardation layer including third anisotropic molecules, a fourth retardation layer including fourth anisotropic molecules, and a third polarizer. Tilt angles of the third anisotropic molecules decrease from the second polarizer side of the third retardation layer toward the fourth retardation layer side of the third retardation layer. Tilt angles of the fourth anisotropic molecules decrease from the third polarizer side of the fourth retardation layer toward the third retardation layer side of the fourth retardation layer. An angle formed by the slow axis of the third retardation layer and the slow axis of the fourth retardation layer is 10° or greater and 20° or smaller.

Abstract: Provided are an optical element that has a high diffraction efficiency and can be produced through a simple procedure, a method of producing the optical element, and a mask set for use in production of the optical element. The optical element of the present invention includes an optically anisotropic layer containing anisotropic molecules. The optically anisotropic layer includes a first region that is a region where the anisotropic molecules are not twist-aligned in a film thickness direction of the optically anisotropic layer, and a second region that is a region where the anisotropic molecules are twist-aligned in the film thickness direction of the optically anisotropic layer.

Abstract: Provided is a reflective liquid crystal display device that can exhibit increased light use efficiency. The reflective liquid crystal display device includes a reflective liquid crystal panel and an optical element disposed on or above an observer side of the reflective liquid crystal panel and including a polarizer and a Pancharatnam-Berry phase diffraction grating. For example, the optical element may include, in order from its reflective liquid crystal panel side toward its observer side, the polarizer, a ?/4 plate, and the Pancharatnam-Berry phase diffraction grating. The Pancharatnam-Berry phase diffraction grating may include a phase difference layer that introduces a phase difference ?nd satisfying the following Formula 1 or Formula 2 to wavelengths ? of 450 nm, 550 nm, and 650 nm.

Abstract: The optical element includes: a first polarizer; a first retardation layer; a second retardation layer; and a second polarizer. First anisotropic molecules near the first polarizer are greater in tilt angle than first anisotropic molecules near an interface with the second retardation layer, with the tilt angles of the first anisotropic molecules continuously changing in a thickness direction. Second anisotropic molecules near the second polarizer are greater in tilt angle than second anisotropic molecules near an interface with the first retardation layer, with the tilt angles of the second anisotropic molecules continuously changing in a thickness direction. Transmission axes of the first and second polarizers are parallel. Slow axes of the first and second retardation layers are parallel. The transmission axis of the first polarizer is parallel to or orthogonal to the slow axes of the first and second retardation layers.

Abstract: Provided is an optical element that can achieve favorable optical characteristics. The optical element of the present invention includes, in the following order: a first alignment film; a first optically anisotropic layer containing a first anisotropic molecules; a second alignment film; and a second optically anisotropic layer containing a second anisotropic molecules.

Abstract: A color filter includes a frame portion in which the reflectance of light incident from the transparent substrate side is less than the reflectance of light incident from the overcoat layer side and an opening portion in which the reflectance of light incident from the transparent substrate side is greater than the reflectance of light incident from the overcoat layer side. The color filter satisfies nbc×dbc<?×A2+?×A+?, where nbc is the refractive index of the transparent base coat layer, dbc nm is the film thickness of the transparent base coat layer, and A is the opening ratio of the color filter, and where A, ?, ?, and ? respectively satisfy A=(area of the opening portion)/(area of an active area), ?=436.7×nbc?837.2, ?=?315.8×nbc+523.7, and ?=?358.3×nbc+771.8.

Abstract: Provided is an optical element including, sequentially from a viewing surface side toward a back surface side: a first polarizer; a negative C plate; a phase difference layer; and a second polarizer. A transmission axis of the first polarizer is parallel to a transmission axis of the second polarizer. The phase difference layer contains anisotropic molecules. In the phase difference layer, a tilt angle of the anisotropic molecules on a viewing surface side in the phase difference layer and a tilt angle of the anisotropic molecules on a back surface side in the phase difference layer are the same as each other and greater than 0°. A slow axis of the phase difference layer, in a case of lying in a tilt direction of the anisotropic molecules, is parallel to or perpendicular to the transmission axis of the first polarizer.

Abstract: Provided is a display device in which warping of a display panel is sufficiently reduced or prevented. The display device includes: a display panel; and a polarizer, the polarizer being provided with at least one notch that extends inward from an outer edge of the polarizer.

Abstract: Provided are a Pancharatnam-Berry phase optical element with less or no occurrence of disclinations and with excellent optical characteristics, and a method of producing a Pancharatnam-Berry phase optical element which is suitable for production of the Pancharatnam-Berry phase optical element above. The Pancharatnam-Berry phase optical element includes: a photoalignment film; and a liquid crystal layer in contact with the photoalignment film. The liquid crystal layer includes alignment domains with reference alignment azimuths of liquid crystal molecules defined by the photoalignment film, the reference alignment azimuths being different from one another. The alignment domains include first alignment domains and second alignment domains, with each of the second alignment domains being positioned between two of the first alignment domains and in contact with each of the two first alignment domains. A difference in reference alignment azimuth between the first alignment domains is not 90°.

Abstract: A color filter includes a frame portion in which the reflectance of light incident from the transparent substrate side is less than the reflectance of light incident from the overcoat layer side and an opening portion in which the reflectance of light incident from the transparent substrate side is greater than the reflectance of light incident from the overcoat layer side. The color filter satisfies nbc×dbc<?×A2+?×A+?, where nbc is the refractive index of the transparent base coat layer, dbc nm is the film thickness of the transparent base coat layer, and A is the opening ratio of the color filter, and where A, ?, ?, and ? respectively satisfy A=(area of the opening portion)/(area of an active area), ?=436.7×nbc?837.2, ?=?315.8×nbc+523.7, and ?=?358.3×nbc+771.8.

Abstract: Provided are an optical element that has a high diffraction efficiency and can be produced through a simple procedure, a method of producing the optical element, and a mask set for use in production of the optical element. The optical element of the present invention includes an optically anisotropic layer containing anisotropic molecules. The optically anisotropic layer includes a first region that is a region where the anisotropic molecules are not twist-aligned in a film thickness direction of the optically anisotropic layer, and a second region that is a region where the anisotropic molecules are twist-aligned in the film thickness direction of the optically anisotropic layer.

Abstract: Provided is an optical element including a phase difference layer. The phase difference layer is a laminate of n first phase difference layers and m second phase difference layers. The n first phase difference layers each contain first anisotropic molecules with tilt angles different between a viewing surface side and a back surface side. The m second phase difference layers each contain second anisotropic molecules with tilt angles different between a viewing surface side and a back surface side. Slow axes of the n first phase difference layers are in a same orientation. Slow axes of the m second phase difference layers are in a same orientation. The slow axes of the n first phase difference layers and the slow axes of the m second phase difference layers are anti-parallel to each other and are parallel to or perpendicular to the transmission axis of the first polarizer.

Abstract: Provided is an optical element including, sequentially from a viewing surface side toward a back surface side: a first polarizer; a negative C plate; a phase difference layer; and a second polarizer. A transmission axis of the first polarizer is parallel to a transmission axis of the second polarizer. The phase difference layer contains anisotropic molecules. In the phase difference layer, a tilt angle of the anisotropic molecules on a viewing surface side in the phase difference layer and a tilt angle of the anisotropic molecules on a back surface side in the phase difference layer are the same as each other and greater than 0°. A slow axis of the phase difference layer, in a case of lying in a tilt direction of the anisotropic molecules, is parallel to or perpendicular to the transmission axis of the first polarizer.