Abstract: The present invention provides a diacetylene derivative represented by the following formula (A) which exhibits liquid crystallinity by itself and has a large refractive index anisotropy or does not exhibit liquid crystallinity by itself but exhibits a large refractive index anisotropy when added to a liquid crystalline compound: R1-Sp1-(Ar1)p-(Ar3)q-(Phe)r-C?C—C?C-(Phe)r-(Ar4)q-(Ar2)p-Sp2-R2??(A) (wherein R1 and R2 are a hydrogen, halogen, cyano, isothiocyanate, alkyl, alkenyl, alkynyl or reactive group, SP1 and SP2 are each a spacer group, Ar1 and Ar2 are each a non-substituted or substituted aromatic carbocyclic or heterocyclic group, Ar3 and Ar4 are each a non-substituted or substituted heterocyclic group, Phe is a non-substituted or substituted 1,4-phenylene group, and p, q and r are each 0 or 1.

Abstract: Disclosed is a highly safe battery separator, in particular a separator for a lithium ion secondary battery, which reduces internal resistance, achieves good ionic conductivity, prevents passing of electrode active materials, and also prevents electrical short circuit by controlling deposition of lithium metal (dendrite). Also disclosed is a means for stably producing the battery separator with high productivity. Specifically disclosed are: a battery separator which is composed of a porous polyolefin sheet that is formed from a group of polyolefin nanofilaments that have an average filament diameter of less than 1 ?m and a filament size distribution of 0.2 or less; and a means for producing the battery separator.

Abstract: The present invention provides a diacetylene derivative represented by the following formula (A) which exhibits liquid crystallinity by itself and has a large refractive index anisotropy or does not exhibit liquid crystallinity by itself but exhibits a large refractive index anisotropy when added to a liquid crystalline compound: R1-Sp1-(Ar1)p-(Ar3)q-(Phe)r-C?C—C?C-(Phe)r-(Ar4)q-(Ar2)p-Sp2-R2??(A) (wherein R1 and R2 are a hydrogen, halogen, cyano, isothiocyanate, alkyl, alkenyl, alkynyl or reactive group, SP1 and SP2 are each a spacer group, Ar1 and Ar2 are each a non-substituted or substituted aromatic carbocyclic or heterocyclic group, Ar3 and Ar4 are each a non-substituted or substituted heterocyclic group, Phe is a non-substituted or substituted 1,4-phenylene group, and p, q and r are each 0 or 1.

Abstract: Disclosed is a highly safe battery separator, in particular a separator for a lithium ion secondary battery, which reduces internal resistance, achieves good ionic conductivity, prevents passing of electrode active materials, and also prevents electrical short circuit by controlling deposition of lithium metal (dendrite). Also disclosed is a means for stably producing the battery separator with high productivity. Specifically disclosed are: a battery separator which is composed of a porous polyolefin sheet that is formed from a group of polyolefin nanofilaments that have an average filament diameter of less than 1 ?m and a filament size distribution of 0.2 or less; and a means for producing the battery separator.

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 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: 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: A transflective liquid crystal display has a liquid crystal cell having a liquid crystal layer sandwiched between a pair of transparent substrates each provided with an electrode. A first polarizer is disposed on a viewer's side of the cell. At least one optical retardation compensator is disposed between the polarizer and the cell. A transflector is disposed behind the viewer's side of the liquid crystal layer. A circular polarizer is provided behind the viewer's side of the transflector. The circular polarizer comprises a second polarizer and an optical anisotropic element having a phase difference of approximately ¼ wavelength in the visible light region. The optical anisotropic element has a liquid crystal film with a fixed nematic hybid orientation structure and a stretched film.

Abstract: A complex diffraction device, which is excellent in designability, easy in setting the diffraction angle, adaptable to size increase, and easy to handle by adding a diffraction function resulting from an uneven pattern to the diffraction device comprising a liquid crystalline layer where the helical orientation of the smectic liquid crystal phase having a helical structure is maintained.

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 circular polarizer having excellent circular polarization characteristics and a liquid crystal display device equipped with the circular polarizer. The circular polarizer is comprised of at least a polarizer and an optical anisotropic element having a phase difference of approximately ¼ wavelength in the visible light region and characterized in that the optical anisotropic element is comprised of at least a liquid crystal film with a fixed nematic hybrid orientation structure.

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 complex diffraction device, which is excellent in designability, easy in setting the diffraction angle, adaptable to size increase, and easy to handle by adding a diffraction function resulting from an uneven pattern to the diffraction device comprising a liquid crystalline layer where the helical orientation of the smectic liquid crystal phase having a helical structure is maintained.

Abstract: As a compensator for use in an OCB mode liquid crystal display there is provided a compensating film capable of making color compensation and attaining such a viewing angle expansion as has not been attainable heretofore. A compensating film for a liquid crystal display, constituted by at least one layer of a compensating film to be used in an OCB mode liquid crystal display, the compensating film being formed by a discotic liquid crystalline material having a fixed orientation form of a discotic liquid crystal, the compensating film being disposed between a driving liquid crystal cell and a pair of upper and lower polarizing plates, and the orientation form being a hybrid orientation in which the angle between discotic liquid crystal directors near the upper interface of the film and the film plane and the angle between discotic liquid crystal directors near the lower interface of the film and film plane are different from each other.

Abstract: Provided is a liquid crystal display device of a TN type which is improved on a display contrast, gray scale characteristics and viewing angle characteristics of a display color. A liquid crystal cell of a TN type for drive is sandwiched by a pair of upper and lower polarizing plates and at least one compensating film which has an extinction axis angle of 5 to 90 degrees as an absolute value and an optical rotating angle of 0.

Abstract: A liquid crystal display device having improved and broadened viewing angle characteristics. The device includes a liquid crystal cell of the twisted nematic type for driving sandwiched by a pair of upper and lower polarizing plates in which at least one compensating film is inserted between the liquid crystal cell and the upper polarizing plate or between the liquid crystal cell and the lower polarizing plate. Alternatively, two compensating films are respectively inserted between the liquid crystal cell and the upper polarizing plate and between the liquid crystal cell and the lower polarizing plate. The compensating film consists essentially of a liquid crystalline polymer showing optically a positive uniaxiality, the liquid crystalline polymer being fixed in a nematic hybrid orientational order.

Abstract: As a compensator for use in an OCB mode liquid crystal display there is provided a compensating film capable of making color compensation and attaining such a viewing angle expansion as has not been attainable heretofore.A compensating film for a liquid crystal display, constituted by at least one layer of a compensating film to be used in an OCB mode liquid crystal display, the compensating film being formed by a discotic liquid crystalline material having a fixed orientation form of a discotic liquid crystal, the compensating film being disposed between a driving liquid crystal cell and a pair of upper and lower polarizing plates, and the orientation form being a hybrid orientation in which the angle between discotic liquid crystal directors near the upper interface of the film and the film plane and the angle between discotic liquid crystal directors near the lower interface of the film and film plane are different from each other.

Abstract: A compensating film capable of compensating both twist structure based on a liquid crystal cell and refractive index anisotropy to diminish the visual angle dependence of a liquid crystal display is provided.The film is formed using a discotic liquid crystalline material and the orientation form of the discotic liquid crystal is a twisted orientation.

Abstract: A viewing angle compensator for a liquid crystal display having characteristics such as being able to diminish the visual angle dependency of the liquid crystal display is provided. The viewing angle compensator of the present invention comprises a light transmitting base and a film of a liquid crystalline polymer formed on the base, the liquid crystalline polymer taking in the state of liquid crystal a structure wherein a refractive index in the thickness direction is larger than a refractive index in any direction within the plane of the polymer and assuming a glassy state at a temperature lower than the liquid crystal transition point thereof.