A reflective-type color display according to the present disclosure includes a lower substrate and an upper substrate, a polarization plate positioned on an outer surface of the upper substrate, a plurality of helical photonic crystals arranged between the lower substrate and the upper substrate and having different reflection properties of light in the visible region, and a tunable wave plate positioned on the plurality of helical photonic crystals to control the reflection intensity by continuously changing the phase retardation. According to an embodiment, it is possible to simultaneously achieve the features of three primary colors, analog grey levels, high resolution, and fast response through the separation of the function of color reflection from the intensity tuning capability of the photonic crystal, beyond the limitation of existing reflective-type display technology.

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.

A device is provided. The device includes an optical film including optically anisotropic molecules configured to form a plurality of helical structures with a plurality of helical axes and a helical pitch. The helical pitch is a distance along a helical axis over which an azimuthal angle of an optically anisotropic molecule vary by a predetermined value. Over the helical pitch of a helical structure, the azimuthal angle of the optically anisotropic molecule is configured to vary nonlinearly with respect to a distance from a starting point of the helical pitch to a local point at which the optically anisotropic molecule is located along the helical axis.

Provided are an optical laminate in which a large diffraction angle can be obtained, a light guide element, and an AR display device. The optical laminate includes, in the following order: a first optically-anisotropic layer that is formed of 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 continuously rotates in at least one in-plane direction; a phase difference layer; and a patterned cholesteric liquid crystal layer that is formed of 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 continuously rotates in at least one in-plane direction, the liquid crystal compound being cholesterically aligned, in which in the first optically-anisotropic layer and the patterned cholesteric liquid crystal layer, the one in-plane directions in which the direction of the optical axis derived from the liquid crystal compound continuously rotates are the same, and rotation directions of the direction of the optical axis derived from the liquid crystal compound in the one in-plane direction are the same.

A liquid crystal display device including, sequentially in the following order: a light source unit, a rear side polarizer, a liquid crystal cell, a front side polarizer, and a viewing angle expansion film. Alternatively, a liquid crystal display device including, sequentially in the following order: a light source unit, a rear side polarizer, a liquid crystal cell, a viewing angle expansion film, and a front side polarizer. The liquid crystal display device optionally includes a rear side optical film provided between the rear side polarizer and the liquid crystal cell; and a front side optical film provided between the front side polarizer and the liquid crystal cell.

The half mirror includes a retardation layer, a circularly polarized light reflecting layer, and a front panel that are disposed in this order. The retardation layer has a front phase difference as measured at a wavelength of 500 nm of 107 to 127 nm and a front phase difference as measured at a wavelength of 475 nm of 110 to 130 nm. The circularly polarized light reflecting layer includes three cholesteric liquid crystal layers. The three cholesteric liquid crystal layers have different selective reflection center wavelengths 1, 2, and X,3. The center wavelengths 1, 2, and 3 satisfy 380 nm<1<500 nm and 520 nm<2<3<780 nm. The cholesteric liquid crystal layer having the center wavelength 1 is disposed nearest to the front panel side.

Each of a mirror surface display device and a light reflecting member includes a support member having an optical thin film thereon, a broadband selective reflection film and a display in this order; the optical thin film being formed on a surface of the support member facing the broadband selective reflection film; and the broadband selective reflection film being a film selectively transmitting one of clockwise circularly polarized light and counterclockwise circularly polarized light, and selectively reflecting the other polarized light, and having cholesteric regularity.

According to the present invention, there is provided a plurality of protruding portions that are formed on one surface of the support and have inclined surfaces parallel to each other; a cholesteric liquid crystal layer that is formed on each of the inclined surfaces of the protruding portions; and an overcoat layer that is laminated on the surface of the support on which the protruding portions are formed so as to cover the cholesteric liquid crystal layer, in which a normal line of each of the inclined surfaces of the protruding portions is parallel to a spiral axis of the cholesteric structure of the cholesteric' liquid crystal layer, an angle formed between a normal line of a surface of the overcoat layer and the spiral axis of the cholesteric structure is 5 to 42, a difference in refractive index between the cholesteric liquid crystal layer and the protruding portion and a difference in refractive index between the cholesteric liquid crystal layer and the overcoat layer are 0.2 or less.

A display device including a display module and an eyepiece lens is provided. A user can view an image realized by the display module through the eyepiece lens. In the display play according to the present disclosure, a path of a light moving from the display module to the eyepiece lens may be increased by a half-mirror and a reflective polarizing plate which are located between the display module and the eyepiece lens. Thus, in the display device according to the present disclosure, the overall thickness may be decreased without degrading the quality of the image realized by the display module.

A composition for preparing an optical functional layer capable of forming an optical film having an excellent surface condition and excellent lamination properties with another layer, includes a liquid crystal compound and a copolymer, and the copolymer includes a constitutional unit corresponding to a fluoroaliphatic group-containing monomer represented by Formula I, and a constitutional unit corresponding to a monomer represented by Formula II. In Formulae I and II, R.sup.1, R.sup.10, and R.sup.3 each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R.sup.2 represents an alkyl group having 1 to 20 carbon atoms in which at least one carbon atom has a fluorine atom as a substituent, and L represents a divalent linking group constituted by at least one selected from the group consisting of O, (CO)O, O(CO), a divalent chain group, and a divalent aliphatic cyclic group.

##STR00001##