Abstract: An optical diode. A cholesteric liquid crystal (CLC) layer has a selective reflection wavelength band with a left-handed helical structure, and a phase shifter for changing a phase difference between two intrinsic polarized light components of left-handed circularly polarized light having a wavelength within the selective reflection wavelength band of the CLC layer. When left-handed circularly polarized light having a wavelength within the selective reflection wavelength band of the CLC layer is incident on the phase shifter in the optical diode, the phase shifter turns the left-handed circularly polarized light into right-handed circularly polarized light, which can be transmitted through the CLC layer. When left-handed circularly polarized light having a wavelength within the selective reflection wavelength band of the CLC layer is incident on the CLC layer, it is selectively reflected by the CLC layer.

Abstract: A latent image forming film comprising: a reflective layer; and a polarization converting and rotating layer placed on a surface of the reflective layer, the polarization converting and rotating layer changing an ellipticity of polarized incident light and concurrently rotating a polarization direction of the polarized incident light.

Abstract: An identification medium is to be observed via a linearly polarizing filter and includes a first liquid crystal layer that changes the wavelength of light according to the rotational angle of the linearly polarizing filter, a cholesteric liquid crystal layer, and a light absorbing layer that is provided below the cholesteric liquid crystal layer.

Abstract: A method for producing a wire-grid polarizer includes the steps of preparing a resin film including a concave part formed thereon, the concave part having a submicron-sized grating pattern, the resin film having a visible light transmittance of 80% or more; filling the concave part with an electroconductive nano-material having an average diameter equal to or smaller than one-half of an average line width of the concave part; and removing the electroconductive non-material which has not been filled into the concave part.

Abstract: The nanoimprint mold of the invention comprises a liquid crystal substance and has an indentation surface on which a relief structure is formed by orientation of the liquid crystal substance. The nanoimprint mold can be easily produced without providing joints, even when the area of the transfer indentation surface is large.

Abstract: An object of the present invention is to provide a discrimination medium which has high discrimination ability, and which is more difficult to counterfeit than conventional discrimination mediums. A discrimination medium comprises: a cholesteric liquid crystal layer; and a liquid crystal layer acting as a half-wave plate and provided on the cholesteric liquid crystal layer in a predetermined pattern.

Abstract: A circular polarizer includes at least an optically anisotropic element, a transmissive protection film and a polarizing element sandwiched therebetween. The optically anisotropic element has a liquid crystal layer aligned on a cellulose triacetate film and a retardation of approximately ¼ wavelength in the visible light region. The liquid crystal layer includes a liquid crystal film with a fixed twisted nematic alignment. The circular polarizer is suppressed in thickness by simplifying the layer structure without causing defects, such as peeling off the layers, even under elevated temperature and humidity condition and makes it possible to set arbitrarily the angle of the alignment axis direction of the optically anisotropic element including a liquid crystal layer with a fixed twisted alignment with respect to the absorption axis of the polarizing element, so that the optically anisotropic element and polarizing element both in the form of an elongate film can be laminated continuously to one another.

Abstract: An optical diode which can lower the cost and save electric power is provided. An optical diode 21 of the present invention comprises a cholesteric liquid crystal (CLC) layer 2 having a selective reflection wavelength band with a left-handed helical structure, and a phase shifter 24 for changing the phase difference between two intrinsic polarized light components of left-handed circularly polarized light having a wavelength within the selective reflection wavelength band of the CLC layer 2. When left-handed circularly polarized light having a wavelength within the selective reflection wavelength band of the CLC layer 2 is incident on the phase shifter 24 in the optical diode 21, for example, the phase shifter 24 turns the left-handed circularly polarized light into right-handed circularly polarized light, this right-handed circularly polarized light can be transmitted through the CLC layer 2.

Abstract: A laser oscillation element 1 according to the invention comprises a cholesteric liquid crystal layer 2 containing cholesteric liquid crystals, a cholesteric liquid crystal layer 3 containing cholesteric liquid crystals facing the cholesteric liquid crystal layer 2, and a defect layer 4 containing a dye 5 which emits fluorescence upon optical excitation disposed between the cholesteric liquid crystal layers 2, 3. A selective reflection wavelength band in the cholesteric liquid crystals overlaps with the emission band of the fluorescence emitted by the dye 5, the helical winding directions of the cholesteric liquid crystals contained in the cholesteric liquid crystal layers 2, 3 are identical, and the transition moments of the dye 5 are aligned parallel to the surfaces of the cholesteric liquid crystal layers 2, 3. According to the laser oscillation element 1, a laser oscillation can be generated with high efficiency. Moreover, continuous wave lasing can be generated.

Abstract: An object identification structure for generally distributed products is provided which is extremely hard to forge, high in identifiability, and can be manufactured inexpensively. The object identification structure comprises a single layer cholesteric liquid crystal film which is substantially colorless and transparent when viewed from the front and appears colored when viewed from a predetermined oblique direction.

Abstract: An optical laminate comprising, laminated in the order mentioned, a support substrate, adhesive layer, cholesteric liquid crystal layer and protection layer, characterized in that the cholesteric liquid crystal layer has in at least part thereof an area indicating a diffraction power. The optical laminate is used for a polarization diffraction element, liquid crystal display device compensation element, decorative member, and forgery prevention element.

Abstract: According to the present invention, a method is provided for manufacturing a polarization diffraction film, which comprises the steps of forming a film with a liquid crystal material containing a liquid crystalline polymer and a crosslinkable substance, fixing a cholesteric alignment formed with the liquid crystal material, crosslinking the liquid crystal material to form a liquid crystal film and providing a region exhibiting a diffraction-capability on at least a part of the liquid crystal film or polarization diffraction film or comprises the steps of forming a film with a liquid crystal material containing a polymeric liquid crystal and a crosslinkable substance, crosslinking the liquid crystal material in a cholesterically aligned state so as to form a liquid crystal film with a cholesteric alignment fixed and providing a region exhibiting a diffraction capability on at least a part of the liquid crystal film.

Abstract: A transflective liquid crystal display providing a bright displayed image of high contrast in the transmission mode with less dependence on the viewing angle by combining a polarizer with an optically anisotropic element having a liquid crystal film in which a twisted nematic alignment stricture is secured to produce a circular polarizer and disposing the circular polarizer on the rear side of a transflector in the transflective liquid crystal display.

Abstract: An authenticity identifying film (10) has a reflective film (11) having a circularly polarized light selectivity to reflect at least only either of right-handed circularly polarized light and left-handed circularly polarized light of incident light to produce reflected light. The reflective film (11) is provided with a hologram forming part (11a). The hologram forming part (11a) reflects circularly polarized light of the same circular polarization as that of the reflected light in a direction different from that of the reflected light to form a holographic image. The reflected light reflected by the reflective film (11) and the holographic image formed by the hologram forming part (11a) are detected by detectors disposed at different positions, respectively.

Abstract: A liquid crystalline film which functions suitably as a polarization rotating lattice is provided. The liquid crystalline film is characterized in that a cholesteric orientation or a chiral smectic C orientation, in which helical axis is not uniformly parallel in the thickness direction of the film nor is helix pitch of helices uniformly equal in the film thickness direction, is formed in a certain region of the film.

Abstract: A reflection liquid crystal display device comprising a liquid crystal cell where a liquid crystal layer is provided between two opposed electrode substrates, a reflecting layer, and a cholesteric liquid crystal film, characterized in that the ratio (SCE/SCI) of the specular component excluded-refelctance (SCE) to the specular component included-reflectance (SCI) of the cholesteric liquid crystal film is 15% or more, the wavelenght bandwidth of the cholesteric selective reflection ranges from 30 mm to 150 nm, and the center wavelength of the cholesteric selective reflection is in the visible range of 380-780 nm or in the near-infared range of 800-2000 nm.

Abstract: A transflective liquid crystal display providing a bright displayed image of high contrast in the transmission mode with less dependence on the viewing angle by combining a polarizer with an optically anisotropic element having a liquid crystal film in which a twisted nematic alignment stricture is secured to produce a circular polarizer and disposing the circular polarizer on the rear side of a transflector in the transflective liquid crystal display.

Abstract: A light-diffusible liquid crystalline film having a fixed cholesteric or chiral smectic C orientation in which the helical axis direction is not uniformly parallel to the film thickness direction, as well as a liquid crystalline film having a fixed cholesteric or chiral smectic C orientation in which the helical axis direction is not uniformly parallel to the film thickness direction nor is the helix pitch uniformly equal in the film thickness direction, are provided.

Abstract: A reflection liquid crystal display device comprising a liquid crystal cell where a liquid crystal layer is provided between two opposed electrode substrates, a reflecting layer, and a cholesteric liquid crystal film, characterized in that the ratio (SCE/SCI) of the specular component excluded-refelctance (SCE) to the specular component included-reflectance (SCI) of the cholesteric liquid crystal film is 15% or more, the wavelenght bandwidth of the cholesteric selective reflection ranges from 30 mm to 150 nm, and the center wavelength of the cholesteric selective reflection is in the visible range of 380-780 nm or in the near-infared range of 800-2000 nm.

Abstract: An authenticity identifying film (10) has a reflective film (11) having a circularly polarized light selectivity to reflect at least only either of right-handed circularly polarized light and left-handed circularly polarized light of incident light to produce reflected light. The reflective film (11) is provided with a hologram forming part (11a). The hologram forming part (11a) reflects circularly polarized light of the same circular polarization as that of the reflected light in a direction different from that of the reflected light to form a holographic image. The reflected light reflected by the reflective film (11) and the holographic image formed by the hologram forming part (11a) are detected by detectors disposed at different positions, respectively.