An optical system of the present disclosure includes: a first optical system including a polarization conversion element aligning a polarization direction of light including color light beams with a predetermined polarization direction, and generating illumination light including the color light beams; a first polarization rotation element disposed at a first pupil position inside the first optical system, including first and second divided regions, in which the first and second divided regions have different polarization characteristics with respect to a first color light beam outputted from the polarization conversion element; a polarizer disposed between the polarization conversion element and the first polarization rotation element, and reducing light in a polarization direction other than the predetermined polarization direction included in light outputted from the polarization conversion element; and light valves each illuminated by at least the first color light beam included in the illumination light generated by the first optical system.

Provided is a reflective screen and a projection image display system in which a transmittance of light can be selectively changed, a transmittance in a transparent state is sufficiently high, a voltage does not need to be applied constantly, and a voltage is applied to decrease a transmittance of light in a case where the reflective screen is irradiated with video light. The reflective screen includes: a light reflecting layer that is formed of a cholesteric liquid crystal layer and where a selective reflection wavelength at a polar angle of 60° is present in a visible range, in which senses of helix of all of cholesteric liquid crystal layers are the same and Expression (1) is satisfied; and a transparent first electrode, a transparent second electrode, and a light control layer that are provided on a rear side with respect to the light reflective layer, the light control layer being disposed between the first electrode and the second electrode, in which the light control layer includes a polymer network and liquid crystal molecules and changes between a first state where light is scattered and a second state where transmission of light is allowed by changing a magnitude of a voltage applied, the polymer network having a three-dimensional net shape having a plurality of domains, and the liquid crystal molecules being positioned in the domains.

R[−60,40](550)/R[−60,30](550)≥1.5  Expression (1)

Provided is a liquid crystal composition that is capable of forming a light absorption anisotropic film having a high degree of alignment, excellent moisture-heat resistance, and excellent alignment uniformity, a light absorption anisotropic film, a laminate, and an image display device. The liquid crystal composition includes a liquid crystal compound, a first dichroic substance having a structure represented by Formula (1), and a second dichroic substance having a structure represented by Formula (2).

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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.

According to one embodiment, in a display device a first panel includes a first polarizing plate, a second polarizing plate, and a first liquid crystal panel interposed between the first polarizing plate and the second polarizing plate, a second panel includes a third polarizing plate, a fourth polarizing plate, and a second liquid crystal panel interposed between the third polarizing plate and the fourth polarizing plat, and a polarizing plate, which is located second from a surface close to an illumination device and a surface closest to an observer, has an extinction ratio that is lower than that of each of the other polarizing plates.

A liquid crystal display device includes a first polarizer, a liquid crystal cell, and a second polarizer in this order from a viewing side, in which a first light absorption anisotropic layer is disposed on the viewing side of the liquid crystal cell, a second light absorption anisotropic layer is disposed on a non-viewing side of the liquid crystal cell, the first and second polarizers each have an absorption axis in a film surface, the absorption axis of the first polarizer is orthogonal to the absorption axis of the second polarizer, an angle θ1 between a transmittance central axis of the first anisotropic layer and a normal line of the film is in a range of 0° to 45°, and an angle θ2 between a transmittance central axis of the second anisotropic layer and a normal line of the film is in a range of 0° to 45°.

Provided is a composition capable of forming an optically anisotropic film exhibiting reverse wavelength dispersibility and an Nz factor of about 0.50 (0.40 to 0.60); as well as an optically anisotropic, a circularly polarizing plate, and a display device. The composition includes a non-colorable rod-like compound having an acid group or a salt thereof, a non-colorable plate-like compound having an acid group or a salt thereof, and a salt consisting of a cation and an anion, and exhibiting lyotropic liquid crystallinity, in which a ratio W obtained by Expression (W) is 0.25 to 1.75, and a maximum absorption wavelength in a wavelength range of 230 to 400 nm of the rod-like compound is smaller than a maximum absorption wavelength in a wavelength range of 230 to 400 nm of the plate-like compound.

[00001]$\begin{array}{cc}\mathrm{Ratio}W=\frac{\left(C1+C2+C3\right)-\left(A1+A2\right)}{A2}& \left(W\right)\end{array}$

Provided is a composition capable of forming an optically anisotropic film exhibiting reverse wavelength dispersibility and an Nz factor of about 0.50 (0.40 to 0.60); as well as an optically anisotropic, a circularly polarizing plate, and a display device. The composition includes a non-colorable rod-like compound having an acid group or a salt thereof, a non-colorable plate-like compound having an acid group or a salt thereof, and a salt consisting of a cation and an anion, and exhibiting lyotropic liquid crystallinity, in which a ratio W obtained by Expression (W) is 0.25 to 1.75, and a maximum absorption wavelength in a wavelength range of 230 to 400 nm of the rod-like compound is smaller than a maximum absorption wavelength in a wavelength range of 230 to 400 nm of the plate-like compound.

[00001]$\begin{array}{cc}\mathrm{Ratio}W=\frac{\left(C1+C2+C3\right)-\left(A1+A2\right)}{A2}& \left(W\right)\end{array}$

Provided is a polymerizable liquid crystal composition capable of suppressing the generation of precipitates; and an optically anisotropic layer, an optical film, a polarizing plate, and an image display device. The polymerizable liquid crystal composition contains a forward wavelength dispersion liquid crystal compound A having an aromatic ring having 10 or more π electrons and a forward wavelength dispersion liquid crystal compound B having an aromatic ring having 6 or more and less than 10 π electrons.

Provided is a meta optical device including a plurality of phase modulation regions respectively including a plurality of nanostructures and configured to modulate a phase of incident light, wherein a phase retardation profile of the plurality of phase modulation regions monotonically change with respect to light of a plurality of wavelength bands apart from each other, and wherein phase modulation ranges with respect to the light of the plurality of wavelength bands are different from each other.