The present invention relates to a composite material, a liquid crystal film, a method for preparing the film, a temperature-responsive device comprising the film, and a circular polarizer made therefrom. The liquid crystal film comprises the composite material of the present invention, wherein the composite material comprises a polymer network of a cholesteric liquid crystal material, and a chiral material capable of hydrogen-bond-assisted self-assembly, and wherein the chiral material is dispersed in and restrained by the polymer network. The obtained liquid crystal film can exhibit a high reflectivity and a high transmittance as well as a broad band reflection. And, the liquid crystal film is applicable for an industrial development because it can be produced with a simple process and at a lower cost, and requires a lower UV luminous intensity.

The present invention relates to a composite material, a liquid crystal film, a method for preparing the film, a temperature-responsive device comprising the film, and a circular polarizer made therefrom. The liquid crystal film comprises the composite material of the present invention, wherein the composite material comprises a polymer network of a cholesteric liquid crystal material, and a chiral material capable of hydrogen-bond-assisted self-assembly, and wherein the chiral material is dispersed in and restrained by the polymer network. The obtained liquid crystal film can exhibit a high reflectivity and a high transmittance as well as a broad band reflection. And, the liquid crystal film is applicable for an industrial development because it can be produced with a simple process and at a lower cost, and requires a lower UV luminous intensity.

The present disclosure provides a liquid crystal composition, a liquid crystal display device and its manufacturing method. The liquid crystal composition comprises a first composition and an ethylene-vinyl acetate copolymer at a ratio by mass of the first composition to the ethylene-vinyl acetate copolymer of 2:3 to 4:1, wherein the first composition comprises 15 to 40 parts by weight of a chiral cholesterol ester compound, 59 to 75 parts by weight of nematic phase liquid crystal, and 1 to 10 parts by weight of ferroferric oxide. The liquid crystal display device comprises a liquid crystal display panel, a first transparent electrode, a liquid crystal composition layer, and a second transparent electrode.

The present disclosure provides a liquid crystal composition, a liquid crystal display device and its manufacturing method. The liquid crystal composition comprises a first composition and an ethylene-vinyl acetate copolymer at a ratio by mass of the first composition to the ethylene-vinyl acetate copolymer of 2:3 to 4:1, wherein the first composition comprises 15 to 40 parts by weight of a chiral cholesterol ester compound, 59 to 75 parts by weight of nematic phase liquid crystal, and 1 to 10 parts by weight of ferroferric oxide. The liquid crystal display device comprises a liquid crystal display panel, a first transparent electrode, a liquid crystal composition layer, and a second transparent electrode.

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 object is to provide an optical system capable of improving the brightness of a main image while eliminating a ghost image. In an optical system including: an image display device that emits an image; a linear polarizer through which light associated with the image passes; a first quarter wavelength plate which receives the light from the linear polarizer; a half mirror; a reflective polarizer; and a second quarter wavelength plate provided between the reflective polarizer and the half mirror, retardance of the first quarter wavelength plate and retardance of the second quarter wavelength plate are equal, and thus the object is achieved.

An object is to provide an optical system capable of improving the brightness of a main image while eliminating a ghost image. In an optical system including: an image display device that emits an image; a linear polarizer through which light associated with the image passes; a first quarter wavelength plate which receives the light from the linear polarizer; a half mirror; a reflective polarizer; and a second quarter wavelength plate provided between the reflective polarizer and the half mirror, retardance of the first quarter wavelength plate and retardance of the second quarter wavelength plate are equal, and thus the object is achieved.

An object is to provide an optical system capable of improving the brightness of a main image while eliminating a ghost image. In an optical system including: an image display device that emits an image; a linear polarizer through which light associated with the image passes; a first quarter wavelength plate which receives the light from the linear polarizer; a half mirror; a reflective polarizer; and a second quarter wavelength plate provided between the reflective polarizer and the half mirror, retardance of the first quarter wavelength plate and retardance of the second quarter wavelength plate are equal, and thus the object is achieved.

An object is to provide an optical system capable of improving the brightness of a main image while eliminating a ghost image. In an optical system including: an image display device that emits an image; a linear polarizer through which light associated with the image passes; a first quarter wavelength plate which receives the light from the linear polarizer; a half mirror; a reflective polarizer; and a second quarter wavelength plate provided between the reflective polarizer and the half mirror, retardance of the first quarter wavelength plate and retardance of the second quarter wavelength plate are equal, and thus the object is achieved.

A liquid-crystalline medium having a nematic phase comprising one or more compounds of formula I

##STR00001## and a negative dielectric component. It can be used in liquid-crystal electrooptical elements, particularly in liquid-crystal lenses. The mixtures have high optical anisotropy and high refractive index, simultaneously they are suitable for fast switching combined with low power consumption using a dual frequency addressing.