A liquid crystal light shutter whose transmittance can be controlled by ambient conditions, such as incident solar UV intensity and outdoor temperature, is demonstrated. Self‐shading by optical or thermal switching between transparent and opaque states is achieved by liquid crystals doped with push–pull azobenzene and can be used for energy‐saving smart windows. The self‐shading light shutter is transparent during cool weather or under weak sunlight, which could save the energy used for heating and lighting, and can be switched from transparent to opaque during warm weather or under strong sunlight, saving energy used for cooling.

We propose an optically and electrically switchable cholesteric liquid crystal (ChLC) cell doped with a push–pull azo dye.

Guest-host liquid crystal (GHLC) consists of host liquid crystal and guest dichroic dye. It can be switched between the transparent and opaque states by controlling the light absorption. In this paper, transmission control via the phase transition in GHLCs is presented. The smectic A, nematic, and isotropic phases as the high-, mid-, and low-transmittance states of a GHLC cell are used, respectively, to control the transmittance. It is demonstrated that the proposed GHLC cell can be used as a self-shading smart window for energy saving, which allows people to see through it even when it is darkened.

We propose an optical compensation scheme that uses uniaxial films for perfect elimination of light leakage over the entire viewing cone in a homogeneously-aligned liquid crystal cell. Uniaxial films with different dispersion characteristics are used so that they can compensate one another to achieve achromatic optical compensation. Owing to the rotational symmetry of the polarization change on the S(2)-S(3) plane of the Poincaré sphere, we can eliminate the light leakage at all azimuth angles. The contrast ratio of the proposed configuration for white light is higher than 3000:1 at a polar angle of ± 85°, irrespective of the azimuth angle.

Recently, low-frequency driving of liquid crystal display (LCD) panels to minimize power consumption has drawn much attention. In the case in which an LCD panel is driven by a fringe-field at a low frequency, the image flickering phenomenon occurs when the sign of the applied electric field is reversed. We investigated image flickering induced by the flexoelectric effect in a fringe-field switching (FFS) liquid crystal cell in terms of the transmittance difference between frames and the ripple phenomenon. Experimental results show that image flicker due to transmittance difference can be eliminated completely and that the ripple phenomena can be reduced significantly by applying a bipolar voltage wave to the FFS cell.