Provide are an optical element that can improve a utilization efficiency of light while increasing an optical path length, an image display unit, and a head-mounted display. The optical element includes, in the following order: a first absorptive linearly polarizing plate; a first reflective linearly polarizing plate; a first retardation plate; a partially reflecting mirror; a second retardation plate; and a second reflective linearly polarizing plate, in which a turning direction of circularly polarized light that is reflected from the first reflective linearly polarizing plate in a case where light transmits through the first retardation plate and is incident into the first reflective linearly polarizing plate is opposite to a turning direction of circularly polarized light that is reflected from the second reflective linearly polarizing plate in a case where light transmits through the second retardation plate and is incident into the second reflective linearly polarizing plate.

The present invention provides a polymerizable cholesteric liquid crystal composition containing: one or two or more polymerizable liquid crystal compounds (I) having two or more polymerizable functional groups in the molecule; a chiral compound (III); a polymerization initiator (IV); optionally a non-silicon compound (V) having a repeating unit; and optionally one or two or more polymerizable liquid crystal compounds (II) having one polymerizable functional group. An optically anisotropic body formed from a polymerizable liquid crystal composition according to the present invention is also provided.

A liquid crystal display apparatus includes: a liquid crystal cell; a viewer side polarizing plate; a back-surface side polarizing plate, a reflective polarizer, a first prism sheet, a second prism sheet, and a wavelength conversion layer. The first prism sheet and the second prism sheet each has: a first main surface, which is flat; and a second main surface, on which a plurality of unit prisms are arrayed. In the liquid crystal display apparatus, convex portions formed by the plurality of unit prisms on the second main surface of the first prism sheet are bonded to a main surface of the reflective polarizer on an opposite side to the back-surface side polarizing plate, and/or convex portions formed by the plurality of unit prisms on the second main surface of the second prism sheet are bonded to the first main surface of the first prism sheet.

A vehicle mirror with an image display function includes a half mirror and an image display device, the half mirror includes an n?/4 retardation film and a reflection layer, n is 1, 3, 5, or 7, the n?/4 retardation film, the reflection layer, and the image display device are disposed in this order in the mirror with an image display function, and the reflection layer is a linear polarization reflection layer or a circular polarization reflection layer.

Provided are: an image display apparatus that can display augmented reality in a virtual image is superimposed on a bright real scene; and AR glasses including the image display apparatus. The image display apparatus includes: a display element; and a reflective polarization diffraction element that reflects an image displayed by the display element, in which the polarization diffraction element has a region where a period of a diffraction structure decreases in a direction away from the display element.

The present invention provides a polymerizable compound denoted by Formula (I): in the formula, Z.sup.1 and Z.sup.2 represent an arylene group, and the like, m represents 1 or 2, n represents an integer of 0 or 1, and when m is 2, n is 0, L.sup.1, L.sup.2, L.sup.3, and L.sup.4 each independently represent a linking group such as C(O)O and OC(O), T.sup.3 represents -Sp.sup.4-R.sup.4, X represents O, and the like, r represents 1 to 4, Sp.sup.1, Sp.sup.2, Sp.sup.3, Sp.sup.4, and Sp.sup.5 each independently represent a single bond or a linking group, R.sup.1 and R.sup.2 each independently represent a polymerizable group, and R.sup.3, R.sup.4, and R.sup.5 each independently represent a hydrogen atom, a polymerizable group, or the like; a polymerizable composition containing the polymerizable compound described above; a film formed of the polymerizable composition described above; and a half mirror for displaying a projection image including the film described above. ##STR00001##

An optical sheet member includes a polarizing plate including a polarizer, a brightness enhancement film including a reflection polarizer, and a /4 plate, in which the reflection polarizer includes a first light reflecting layer which has a reflection center wavelength range of 430 nm to 480 nm, and is formed by fixing a cholesteric liquid crystalline phase emitting circular polarization light, a second light reflecting layer which has a reflection center wavelength range of 500 nm to 600 nm, and a third light reflecting layer which has a reflection center wavelength range of 600 nm to 650 nm, and both formed by fixing a cholesteric liquid crystalline phase emitting circular polarization light, and the brightness enhancement film includes the /4 plate satisfying 550 nm/425 nm<Re(550)<550 nm/4+25 nm between the polarizer and the reflection polarizer.

A liquid crystal element (1) includes helical structures (7). The liquid crystal element (1) has a light incidence surface (13) on which light is incident and a reflective surface (17) which reflects the light coming through the light incidence surface (13). Each helical structure (7) includes structure units (9). Each structure unit (9) includes liquid crystal molecules (11) stacked in a twisted manner to form a helix. A second end (E2) of one structure unit (9) of structure units (9) adjacent to one another in a first direction (A1) serves as a first end (E1) of the other structure unit (9). Directions of orientation of the liquid crystal molecules (11) at the first ends (E1) included in the helical structures (7) are identical. The reflective surface (17) includes at least one of the first ends (E1) included in each helical structure (7). The reflective surface (17) is non-parallel to the light incidence surface (13).

To provide a mirror with an image display function which is capable of displaying a brighter image and has excellent view angle characteristics. A mirror with an image display function includes an image display device, a wavelength plate, and a circular polarization reflection layer in this order, the circular polarization reflection layer includes a cholesteric liquid crystal layer of which a central wavelength of a selective reflection band is positioned in a visible light region, and at least one of the wavelength plate or the circular polarization reflection layer includes a layer formed of a liquid crystal composition containing a disk-like liquid crystal compound.

A backlight unit capable of implementing matrix local dimming using cholesteric liquid crystal and a polarizing portion, and a display apparatus including the backlight unit are provided. A display apparatus may include: a backlight unit; and an image forming unit configured to create an image by performing at least one from among transmitting and blocking light emitted from the backlight unit. The backlight unit may include: a waveguide plate; a cholesteric liquid crystal layer disposed in front of the waveguide plate, and configured to perform at least one from among transmitting and circularly polarizing the light emitted from the waveguide plate, to generate at least one from among transmitted light and circularly polarized light; and a polarizing portion disposed in front of the cholesteric liquid crystal layer, and configured to transmit the transmitted light in a front direction, and to block the circularly polarized light.