The present invention relates to a thermotropic liquid crystal glass in a crystal or quartz shell for indicating a temperature of a food item and thereby preventing individuals from consuming food at undesirable temperatures or accidentally touching or consuming items that are too hot or too cold. The glass shell includes a plurality of thermotropic liquid crystals that absorbs heat from food items and changes color to exhibit at least one of violet blue, blue, green, yellow/amber, brown, gray, and black color. The hot food causes crystals to change to violet blue and alternatively, when exposed to cold food, the crystals turn black. In some embodiments, kitchenware can be integrated with the glass shell or alternatively, can be detachably attached to the kitchenware. In exemplary embodiments, the glass shell can be positioned onto dishware (i.e., plates, bowls, cups, and mugs) and metal utensils (i.e., forks, spoons, and knives).

The present invention describes a liquid crystal composite tuneable device for fast polarisation-independent modulation of an incident light beam comprising: (a) two supporting and functional panels, at least one of them coated with a transparent conductive electrode layer and with optionally at least one additional layer selected from an alignment layer, antireflective coating layer, thermochromic or electrochromic layer, photoconductive or photosensitive layer, and (b) a composite structure sandwiched between said two panels and made of a liquid crystal and porous microparticles infiltrated with said liquid crystal. The porous microparticles have an average refractive index approximately equals to one of the liquid crystal principal refractive indices, matching that of the liquid crystal at one orientational state (for example, parallel n.sub.∥), and exhibiting large mismatch at another orientational state (for example, perpendicular n.sub.⊥). This refractive index mismatch between said microparticles and said liquid crystal is tuned by applying an external electric or magnetic field, thermally or optically.

A fast spectral modulator for modulating intensity, phase, and spectrum of light beam, is described in the present invention. The spectral modulator comprises at least one liquid crystal composite and a photonic structure. Said at least one liquid crystal composite is made of a liquid crystal and porous microparticles infiltrated within said liquid crystal, wherein: (i) said porous microparticles have an average refractive index approximately equals to one of the liquid crystal principal refractive indices; and (ii) concentration of said microparticles in said composite is less than 0.1% for avoiding significant light scattering.

A viewing angle switch module includes a viewing angle limiter, a first electronically controlled viewing angle switch, a second electronically controlled viewing angle switch, a first polarizer, and a second polarizer. The viewing angle limiter has an absorption axis, and an axial direction of the absorption axis is parallel to a thickness direction of the viewing angle limiter. The viewing angle limiter, the first electronically controlled viewing angle switch, the first polarizer, the second electronically controlled viewing angle switch, and the second polarizer are overlapped. An axial direction of a first absorption axis of the first polarizer is parallel to an axial direction of a second absorption axis of the second polarizer. A display apparatus adopting the viewing angle switch module is also provided. The viewing angle switch module and the display apparatus provided by the invention have better light energy utilization rate.

A projection-type display device includes a liquid crystal device, a transmittance measuring device configured to measure a transmittance of a liquid crystal panel, and a cooling device. After a result of measurement of the transmittance by the transmittance measuring device changes by 10% relative to a default value, a control unit controls the cooling device to raise temperatures of a liquid crystal layer to be not less than 60° C. and not more than a nematic-isotropic phase transition temperature Tni-20° C. This makes it possible to efficiently sweep impurities from a display region to the outside of the display region without heating the liquid crystal layer more than necessary. In addition, a liquid crystal volume ratio V1/V2 of a liquid crystal device for blue among a plurality of liquid crystal devices is greater than that of the other liquid crystal panels, where V1 is a volume of liquid crystal at the inner side of a seal material, and V2 is a volume of the liquid crystal layer in the display region.

A viewing angle switch module includes a viewing angle limiter, a first electronically controlled viewing angle switch, a second electronically controlled viewing angle switch, a first polarizer, and a second polarizer. The viewing angle limiter has an absorption axis, and an axial direction of the absorption axis is parallel to a thickness direction of the viewing angle limiter. The viewing angle limiter, the first electronically controlled viewing angle switch, the first polarizer, the second electronically controlled viewing angle switch, and the second polarizer are overlapped. An axial direction of a first absorption axis of the first polarizer is parallel to an axial direction of a second absorption axis of the second polarizer. A display apparatus adopting the viewing angle switch module is also provided. The viewing angle switch module and the display apparatus provided by the invention have better light energy utilization rate.

Certain exemplary embodiments can provide a face mask comprising a liquid crystal sheet and a portion constructed to receive a solution. The solution comprises glycerol and sodium chloride. The liquid crystal sheet is constructed to detect a body temperature of a wearer of the face mask. The liquid crystal sheet is constructed to alert the user if the body temperature if the wearer is above a predetermined threshold.

Diffractive optical structures, lenses, waveplates, devices, systems and methods, which have the same effect on light regardless of temperature within an operating temperature range. Temperature-compensated switchable diffractive waveplate systems, in which the diffraction efficiency can be maximized for the operating wavelength and temperature by means of adjustment of the electric potential across the liquid crystal or other anisotropic material in the diffracting state of the diffractive state, based on prior measurements of diffraction efficiency as a function of wavelength and temperature. The switchable diffractive waveplates can be a switchable diffractive waveplate diffuser, a switchable cycloidal diffractive waveplate, and a switchable diffractive waveplate lens. An electronic controller can apply an electric potential to the switchable diffractive waveplate. Amplitudes of the electric potential can be determined from lookup tables such that diffraction efficiency at an operating wavelength and measured temperature is maximized. A communications channel can transfer the measured temperature from temperature measurement means to the electronic controller.

A projection-type display device includes a liquid crystal device, a transmittance measuring device configured to measure a transmittance of a liquid crystal panel, and a cooling device. After a result of measurement of the transmittance by the transmittance measuring device changes by 10% relative to a default value, a control unit controls the cooling device to raise temperatures of a liquid crystal layer to be not less than 60° C. and not more than a nematic-isotropic phase transition temperature Tni-20° C. This makes it possible to efficiently sweep impurities from a display region to the outside of the display region without heating the liquid crystal layer more than necessary. In addition, a liquid crystal volume ratio V1/V2 of a liquid crystal device for blue among a plurality of liquid crystal devices is greater than that of the other liquid crystal panels, where V1 is a volume of liquid crystal at the inner side of a seal material, and V2 is a volume of the liquid crystal layer in the display region.

The present invention describes a liquid crystal composite tunable device for fast polarisation-independent modulation of an incident light beam comprising: (a) two supporting and functional panels, at least one of them coated with a transparent conductive electrode layer and with optionally at least one additional layer selected from an alignment layer, antireflective coating layer, thermochromic or electrochromic layer, photoconductive or photosensitive layer, and (b) a composite structure sandwiched between said two panels and made of a liquid crystal and porous microparticles infiltrated with said liquid crystal. The porous microparticles have an average refractive index approximately equals to one of the liquid crystal principal refractive indices, matching that of the liquid crystal at one orientational state (for example, parallel n.sub.∥), and exhibiting large mismatch at another orientational state (for example, perpendicular n.sub.⊥). This refractive index mismatch between said microparticles and said liquid crystal is tuned by applying an external electric or magnetic field, thermally or optically.