Abstract: The present invention is to provide a light emitting device which can generate high-intensity light emission, using a fluorescent material containing a rare earth element ion complex and being excellent in durability and also provide the fluorescent material to be used therein. The present invention relates to a light emitting device comprising a semiconductor light emitting element which emits light within the region from near-ultraviolet light to visible light, and a fluorescent material which contains a rare earth element ion complex having an aromatic ring-containing Bronsted acid ion with a pKa value of 7 or less as a ligand and emits light by the action of light of the semiconductor light emitting element.

Abstract: The present invention is to provide a light emitting device which can generate high-intensity light emission, using a fluorescent material containing a rare earth element ion complex and being excellent in durability and also provide the fluorescent material to be used therein. The present invention relates to a light emitting device comprising a semiconductor light emitting element which emits light within the region from near-ultraviolet light to visible light, and a fluorescent material which contains a rare earth element ion complex having an aromatic ring-containing Bronsted acid ion with a pKa value of 7 or less as a ligand and emits light by the action of light of the semiconductor light emitting element.

Abstract: An object of the present invention is to provide a light emitting device which is high in emission intensity and stable, that is to say, a light emitting device in which when an LED or LD having an emission peak at 380 nm to 410 nm is used as an excitation light source of the light emitting device, the emission intensity of a red phosphor does not largely change to some deviation of the emission wavelength of the LED or LD to maintain not only brightness but also a balance at the time when mixed with a blue and green phosphors.

Abstract: The present invention is to provide a light emitting device which can generate high-intensity light emission, using a fluorescent material containing a rare earth element ion complex and being excellent in durability and also provide the fluorescent material to be used therein. The present invention relates to a light emitting device comprising a semiconductor light emitting element which emits light within the region from near-ultraviolet light to visible light, and a fluorescent material which contains a rare earth element ion complex having an aromatic ring-containing Bronsted acid ion with a pKa value of 7 or less as a ligand and emits light by the action of light of the semiconductor light emitting element.

Abstract: The present invention is to provide a light emitting device which can generate high-intensity light emission, using a fluorescent material containing a rare earth element ion complex and being excellent in durability and also provide the fluorescent material to be used therein. The present invention relates to a light emitting device comprising a semiconductor light emitting element which emits light within the region from near-ultraviolet light to visible light, and a fluorescent material which contains a rare earth element ion complex having an aromatic ring-containing Bronsted acid ion with a pKa value of 7 or less as a ligand and emits light by the action of light of the semiconductor light emitting element.

Abstract: The present invention is to provide a light emitting device which can generate light emission long in life, good in color rendering properties, wide in color reproduction range and high in intensity. The present invention relates to a light emitting device having a light emitter which emits light within the region from near-ultraviolet light to visible light, and a fluorescent material containing at least one fluorescent complex which emits light by the action of light from the light emitter, wherein the fluorescent material is irradiated with substantially no light having a wavelength of 350 nm or less.

Abstract: Coloring matters and filters for plasma display panels, which can effectively screen the neon emission radiated from plasma display panels. Squarylium compounds represented by the following formula (I): [in the formula (I), R is a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an alkenyl group which may have a substituent, m is an integer of from 1 to 4, and n is an integer of from 0 to 4], and filters for plasma display panels, made by laminating layers containing these compounds with layers containing ultraviolet absorbers and, if necessary, providing additionally near infrared screening layers, antireflection layers and/or non-glare layers.

Abstract: A recording liquid characterized in that when it is printed with 100% duty and with a resolution of 600×300 dpi on an electrophotographic paper having a S.A.D (Surface Area Difference) of from 6.0 to 9.0 and a pH of from 6 to 8, the S.A.D. of the printed portion is at least 59.5.

Abstract: A recording liquid characterized in that when it is printed with 100% duty and with a resolution of 600×300 dpi on an electrophotographic paper having a S.A.D (Surface Area Difference) of from 6.0 to 9.0 and a pH of from 6 to 8, the S.A.D. of the printed portion is at least 59.5.

Abstract: An organic metal complex having the formula (I): 1

Abstract: A recording liquid characterized in that when it is printed with 100% duty and with a resolution of 600×300 dpi on an electrophotographic paper having a S.A.D (Surface Area Difference) of from 6.0 to 9.0 and a pH of from 6 to 8, the S.A.D. of the printed portion is at least 59.5.

Abstract: Coloring matters and filters for plasma display panels, which can effectively screen the neon emission radiated from plasma display panels.

Abstract: In the invention, there is provided an electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer formed thereon, said photosensitive layer containing an arylamine hydrazone compound represented by the following formula ?I!.

Abstract: An electrophotographic photoreceptor of the present invention comprises on a conductive support a photosensitive layer containing an arylamine hydrazone compound which has --O--A substituent on aryl moiety. The electrophotographic photoreceptor of the present invention exhibits a very high sensitivity and a lowering in residual potential. It is excellent in durability.

Abstract: An optical information processing element characterized by having a photoelectric and a memory layer provided with a function holding an electricity-conducting property which has been changed by radiation of light having a constant wavelength between electrodes at least one of which is provided with a light-transmitting property.

Abstract: An electrophotographic photoreceptor comprising an electrically conductive substrate and a photosensitive layer formed thereon, wherein said photosensitive layer contains an arylamine compound of the following formula (I): ##STR1## wherein X is a hydrogen atom or a group of the formula (II): ##STR2## Y is a group of the formula (III) or (IV):--O--A.sup.1 --O-- (III)--A.sup.2 --O--A.sup.3 -- (IV)wherein, the substituents are defined hereafter.

Abstract: A metal chelate compound comprising a monoazo compound of the following formula (I): ##STR1## (wherein A is a residue forming a hetero ring together with the carbon atom and the nitrogen atom to which it is bonded, B is a residue forming an aromatic group together with the two carbon atoms to which it is bonded, and X is a hydrogen atom or a cation), and a metal, and an optical recording medium comprising a substrate and a recording layer formed thereon for information to be written in and/or read out by laser, wherein said recording layer contains the metal chelate compound comprising a monoazo compound of the above formula (I) and a metal.

Abstract: An electrophotographic photoreceptor comprising an electrically conductive support and a photosensitive layer formed thereon, wherein said photosensitive layer contains at least one member selected from the group consisting of hydrazone compounds of the formulas (I), (II) and (III): ##STR1## wherein X is a hydrogen atom or a group of the formula (IV):--C(R.sup.8).dbd.N--Q.sup.2 (IV)Q.sup.1 is a group of the formula (V), (VI), (VII), (VIII) or (IX); Q.sup.2 is a group of the formula (VI), (VII), (VIII), (IX) or (X); each of Q.sup.3 and Q.sup.

Abstract: A metal chelate compound of a dis-azo compound represented by the following formula (I) with a metal: ##STR1## (wherein A is a residue forming a heterocyclic ring together with the carbon atom and the nitrogen atom to which it is bonded, X is a residue forming an aromatic group together with the two carbon atoms to which it is bonded, and D is an aromatic residue which may have a substituent, or a heterocyclic amine residue which may have a substituent, and Y is a group having active hydrogen) and an optical recording medium having a recording layer provided on a substrate so that information can be written in and/or read out by a laser, wherein the recording layer contains a metal chelate compound of the dis-azo compound represented by the above formula (I), with a metal.

Abstract: An organic electroluminescent device having an organic hole injection transport layer and an organic luminescent layer formed between two conductive layers constituting electrodes, wherein the organic hole injection transfer layer contains a hydrazone compound of the following formula (I): ##STR1## wherein A is a monovalent or bivalent organic group containing at least one aromatic hydrocarbon ring or aromatic hetero ring which may have a substituent, each of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is a hydrogen atom, or an alkyl, aralkyl, aromatic hydrocarbon or heterocyclic group which may have a substitutent, each of R.sup.6 and R.sup.7 is an alkyl, aralkyl, aryl, aromatic hydrocarbon or heterocyclic group which may have a substituent, l is an integer of 0 or 1, m is an integer of 0, 1 or 2, and n is an integer of 1 or 2, provided that A, R.sup.1 and the carbon atom to which R.sup.1 is bonded, or R.sup.6, R.sup.7 and the nitrogen atom to which R.sup.6 and R.sup.