Abstract: In an optical recording method which utilizes hole burning, a plurality of sorts of light absorption centers having different properties are caused to coexist or to exist in the form of layers, thereby to remove the problem that, although the multiplicity of recording is high, the spacial recording density is low, so the overall recording density is low. Accordingly, the present invention can provide an optical recording method of very high recording density.

Abstract: A method for producing a polarizer patterned with a plural number of portions having a polarizing ability or direction of polarization comprising the first step of producing a surface oriented in a pre-determined direction on a substrate, the second step of producing a polymerizable molecular layer which comprises polymerizable molecules on the above surface, the third step of polymerizing the molecules in said polymerizable molecular layer into a desired pattern and the fourth step of removing the unpolymerized portion of said polymerizable molecular layer.

Abstract: A liquid crystal display device includes a phase-plate disposed between a pair of substrates, preferably inside of the electrode, to increase the transmission rate and improve the contrast ratio of the display.

Abstract: A guest-host type liquid crystal composition comprising one or more host liquid crystals and dissolved therein one or more pleochroic dyes having a trans-4-substituted cyclohexyl group, preferably in an amount of 70% by mole or more of said trans-4-substituted cyclohexyl group among 4-substituted cyclohexyl groups, can afford a liquid crystal display device improved in display contrast and good stability due to no photochemical reaction of the liquid crystal composition.

Abstract: Disclosed is a wavelength multiplexing optical recording apparatus comprising laser sources radiating a plurality of laser beams of different wavelengths, an optical system for focusing the laser beams, and an optical recording medium having a plurality of optical recording layers with wavelength sensitivities for selective recording by said laser beams focused by said optical system. The optical recording layers of recording medium are laminated with distances between adjacent layers being made consistent with biased focal positions of the laser beams attributable to the chromatic aberration of the optical system, so that the laser beams are focused on the optical recording layers of corresponding wavelength sensitivities.

Abstract: A desired portion of information stored in the form of holes using hole burning phenomena is erased by irradiating a desired portion of a recording medium with light so as to erase desired holes. In this way it is possible to erase selectively only desired information among information stored in a PHB memory and further to rewrite information in the portion, where information has been erased.

Abstract: A liquid crystal composition containing azo dyes represented by the formula (I.sub.0) ##STR1## wherein X represents ##STR2## A.sup.1 represents --O-- or --NH--; R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aryloxyalkyl group, a dialkylaminoalkyl group, an arylaminoalkyl group, a cycloalkyl group, an alkoxy group, an alkoxyalkoxy group, an arylalkoxy group, an aryl group, a halogen atom or a group of ##STR3## D.sup.1 and D.sup.2 each represents an aromatic group which does not contain an ionic group;U.sup.1 and U.sup.2 each represents a hydrogen atom, a halogen atom, a methyl group, a methoxy group or an ethoxy group;Y.sup.1 represents --O-- or ##STR4## R represents a hydrogen atom, an alkyl group or may be connected to Z.sup.10 to Z.sup.12 to form a ring;Z.sup.4 to Z.sup.12 each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acylamino group or a cyano group, or Z.sup.4 and Z.sup.5, Z.sup.7 and Z.sup.8, and Z.sup.10 and Z.sup.

Abstract: A liquid crystal composition comprising a host liquid crystal material and at least one guest novel anthraquine dye dissolved in said host liquid crystal material has a high order parameter, sufficient solubility in the host liquid crystal and high stability.

Abstract: A liquid crystal composition containing azo dyes represented by the formula (I.sub.0) ##STR1## wherein X represents ##STR2## A.sup.1 represents --O-- or --NH--, R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aryloxyalkyl group, a dialkylaminoalkyl group, an arylaminoalkyl group, a cycloalkyl group, an alkoxy group, an alkoxyalkoxy group, an arylalkoxy group, an aryl group, a halogen atom or a group of ##STR3## D.sup.1 and D.sup.2 each represents an aromatic group which does not contain an ionic group; U.sup.1 and U.sup.2 each represents a hydrogen atom, a halogen atom, a methyl group, a methoxy group or an ethoxy group;Y.sup.1 represents --O-- or ##STR4## R represents a hydrogen atom, an alkyl group or may be connected to Z.sup.10 to Z.sup.12 to form a ring;Z.sup.4 to Z.sup.12 each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acylamino group or a cyano group, or Z.sup.4 and Z.sup.5, Z.sup.7 and Z.sup.8, and Z.sup.10 and Z.sup.

Abstract: The description is concerned with a liquid crystal composition of the guest-host type which contains a pleochroic dye dissolved therein. The dye molecule has an end group or end groups in the molecule represented by the general formula: ##STR1## where Ro designates a straight chain of alkyl group, in which methylene group not adjacent to the nitrogen atom may be substituted by oxygen atom or sulfer atom; R1 designates an alkyl group having a chain length different from that of the alkyl group of Ro or a group ##STR2## in R1 a methylene group not adjacent to the nitrogen atom may be substituted by oxygen atom or sulfur atom, and R2 designates hydrogen atom, alkyl group, alkoxy group, cycloalkyl group or dialkylamino group.

Abstract: An anthraquinone dye and a liquid crystal composition containing the dye are disclosed.The liquid crystal composition is preferably used in an electro-optic cell which enables a good color display utilizing the guest-host effect of the liquid crystal.

Abstract: An anthraquinone dye and a liquid crystal composition containing the same are disclosed. The anthraquinone dye shows a cyan color and has excellent order parameter, solubility and stability. The liquid crystal composition is particularly used in an electro-optic cell, which is interposed between two facing electrode plates and permits the realization of good color displays utilizing the guest-host effect of a liquid crystal.

Abstract: This invention relates to a guest-host type liquid crystal composition and a color liquid crystal display device in which said composition has been sealed. This invention provides a liquid crystal composition containing a specific anthraquinone dye as a pleochroic dye which, as the guest dye, has a degree of orderness of the alignment (order parameter) in the host liquid crystal in the range from 0.5 to 1, shows remarkable contrast between the colored state and the uncolored state, and is excellent in stability to light, heat, and the like. Further, this invention provides a color guest-host type liquid crystal display device in which said liquid crystal composition has been sealed.

Abstract: Pleochroic azo dyes represented by the formula (I): ##STR1## wherein X represents group --OCOR.sup.1 or --COOR.sup.1 (wherein R.sup.1 represents an alkyl group, an alkoxyalkyl group, an alkoxyphenyl group, an alkylcyclohexyl group, an alkoxyalkylcyclohexyl group, a cycloalkylcyclohexyl group, an alkoxycyclohexyl group, or a phenyl group substituted by a substituent selected from among an alkyl group containing 3 to 18 carbon atoms, an alkoxyalkyl group, a cycloalkyl group, an aryl group, a cyano group, a halogen atom, an acyloxy group, a carboxylic acid ester group, and an arylazo group); Y represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an alkoxy group, a nitro group, a cyano group, a carboxylic acid ester group, an acyloxy group, an alkylsulfonyl group, an aryl group, a halogen atom, or group ##STR2## wherein R.sup.2 and R.sup.3 each represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, or R.sup.2 and R.sup.

Abstract: The present liquid crystal composition is characterized by containing a dye of anthraquinone series represented by the following general formula (1) dissolved as a guest in a host liquid crystal: ##STR1## wherein R represents an alkyl group or a cycloalkyl group. The alkyl group or the cycloalkyl group of the dye of anthraquinone series includes those substituted by alkyl, hydroxyl, alkoxy, cycloalkyl, aryl, aryloxy, dialkylamino, or heterocyclic residue. Furthermore, the liquid crystal composition can contain two or more other kinds of the dye of anthraquinone series, or can be used in combination with other dyes. In the dye of anthraquinone series, the group --COOR at the 2-position and the group --CN at the 3-position are particularly important for realization of cyan color and a high S value.The dye of anthraquinone series is particularly effective for preparation of a black dye.

Abstract: A liquid crystal composition comprising a host liquid crystal and at least one perylene dye dissolved therein represented by the formula: ##STR1## wherein X represents an oxygen atom or a sulfur atom, R.sup.1 and R.sup.2 each represents an aryl group when X represents an oxygen atom; or an aryl group or an alkyl group containing 1 to 18 carbon atoms when X represents a sulfur atom.

Abstract: A liquid crystal composition comprising a host liquid crystal And a pleochroic dye dissolved therein as a guest material is described, which is characterized in that the pleochroic dye contains an anthraquinone-based dye yielding a Magenta color and/or an orange color.

Abstract: A liquid crystal composition contains a pleochroic dye which is an anthraquinone dye having the group --OCOO-- in a substituent group. Such a dye shows a reasonable order parameter and good solubility as well as stability in the liquid crystal composition.

Abstract: A pleochroic color display device is provided which comprises a layer of guest-host type liquid crystal sandwiched between two transparent electrodes for driving the liquid crystal, the guest-host liquid crystal containing a dichroic dye as guest material, and a color filter disposed in front or rear of the layer of the guest-host type liquid crystal. High contrast pleochroic color displays can be obtained by selecting a blackish dye as the dichroic dye. Dichroic displays other than white ones can be produced by the use of a single liquid crystal cell and a single color filter (with one color).

Abstract: A liquid crystal composition containing at least one quinophthalone series dye represented by the formula ##STR1## wherein: X represents hydrogen, a chlorine atom or a bromine atom; and R represents --OR.sup.1 or --SR.sup.1, wherein R.sup.1 represents an alkyl group, a cycloalkyl group, an alkoxyalkyl group, a phenyl group, a p-hydroxyphenyl group, a p-cycloalkylphenyl group, a p-alkylphenyl group, a p-alkoxyphenyl group or an aralkyl group; ##STR2## wherein R.sup.2 and R.sup.3 each represents hydrogen, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, a cycloalkyl group, a phenyl group, a p-alkylphenyl group, a p-hydroxyphenyl group, a p-alkoxyphenyl group or an aralkyl group; or a saturated heterocyclic ring.