Patents by Inventor Akihiko Tokida
Akihiko Tokida has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6559473Abstract: An organic light-emitting diode with high luminance and high efficiency comprising an anode, an organic pn-junction and a cathode layered sequentially in this order, wherein the organic pn-junction emits light by an electric current passing through the diode in an electric field applied between the anode and the cathode, characterized in that the organic pn-junction is composed of an organic p-type luminescent-semiconductor thin film and an organic n-type luminescent-semiconductor thin film, wherein one surface of the organic p-type luminescent-semiconductor thin film is in contact with the anode and another surface of the organic p-type luminescent-semiconductor thin film is in contact with the organic n-type luminescent-semiconductor thin film, and one surface of the organic n-type luminescent-semiconductor thin film is in contact with the cathode and another surface of the organic n-type luminescent-semiconductor thin film is in contact with the organic p-type luminescent-semiconductor thin film and whereiType: GrantFiled: June 16, 1997Date of Patent: May 6, 2003Assignee: Hoechst Japan LimitedInventors: Nu Yu, Wen-Bing Kang, Akihiko Tokida
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Patent number: 6361917Abstract: A process for forming a pattern which comprises irradiating with light a film of a poly(arylenevinylene) polymer represented by the following formula (I) —(Ar—CR1=CR2)n— (I) wherein Ar is a substituted or unsubstituted divalent aromatic hydrocarbon group or a substituted or unsubstituted divalent heterocyclic ring group, and the aromatic hydrocarbon group and the heterocyclic ring group may be a fused ring, R1, R2 independently of each other, are H, CN, alkyl, alkoxy are substituted or unsubstituted aromatic hydrocarbon groups or substituted or unsubstituted aromatic heterocycles, which may both be fused rings, and n is an integer of 2 or more. It is preferred that either R1 or R2 is H and more preferred that both R1 and R2 are H.Type: GrantFiled: July 22, 1996Date of Patent: March 26, 2002Assignee: Hoechst AktiengesellschaftInventors: Wen-Bing Kang, Nu Yu, Akihiko Tokida
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Patent number: 6232466Abstract: A process for preparing a stable titanyl phthalocyanine crystal showing at least one diffraction peak at a Bragg angle (2&thgr;±0.2) of 27.3° is disclosed, which comprises treating amorphous or quasi-amorphous titanyl phthalocyanine with a solvent selected from an alcohol solvent, an aromatic solvent, a mixed solvent of an alcohol solvent and an aromatic solvent, or a mixed solvent of an alcohol solvent and water. The resulting titanyl phthalocyanine exhibits high photosensitivity and excellent durability as a photoconductive material of an electrophotographic photoreceptor.Type: GrantFiled: March 19, 1991Date of Patent: May 15, 2001Assignee: Fuji Xerox Co., LTDInventors: Katsumi Daimon, Akihiko Tokida, Katsumi Nukada, Hidemi Nukada, Yasuo Sakaguchi
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Patent number: 6184305Abstract: A radiation absorbing polymer is characterized by having a main chain copolymer containing recurring units of dicarboxylic acid or carboxylic anhydride group with an organic chromophore bonded to the carboxyl group through methylene or alkylene linkage group, where the organic chromophore is bonded to the carboxyl group by esterification reaction. Residual carboxyl groups of the radiation absorbing polymer can optionally be amidized and/or imidized with an aromatic compounds having a reactive amino group. When the photoresist is applied on the antireflective coating and is exposed by radiation such as deep ultraviolet radiation, a resist pattern with high resolving power is formed, which is not affected by standing wave upon manufacturing integrated circuit elements.Type: GrantFiled: May 15, 1998Date of Patent: February 6, 2001Assignee: Clariant Finance (BVI) LimitedInventors: Wen-Bing Kan, Akihiko Tokida, Kayo Aramaki, Hatsuyuki Tanaka, Ken Kimura
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Patent number: 5919579Abstract: An organic electroluminescent device comprising an anode, an organic hole transport layer, an organic emission layer and a cathode layered in this order on a substrate, or, optionally, comprising an additional electron transport layer between the organic emission layer and the cathode, wherein the organic emission layer comprises a naphthalimide derivative represented by formula (1) wherein R.sup.1 is a hydrogen atom, a straight chain or branched chain alkyl group having from 1 to 16 carbon atoms, an aryl group which may have substituents or an aralkyl group which may have substituents, and R.sup.2, R.sup.3, R.sup.4 are special substituents.Type: GrantFiled: January 17, 1997Date of Patent: July 6, 1999Assignee: Hoechst AktiengesellschaftInventors: Wen-Bing Kang, Nu Yu, Akihiko Tokida, Thomas Potrawa, Andreas Winterfeldt
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Patent number: 5871854Abstract: An organic electroluminescence device comprising an anode, an organic hole transport layer, an organic emission layer and a cathode layered in this order on a substrate, or, optionally, comprising an additional electron transport layer between the organic emission layer and the cathode, wherein the organic emission layer comprises a benzoxazinone derivative represented by formula (1), wherein R.sup.1 is a specific acyl group or sulfonyl group, and R.sup.2 and R.sup.3 are specific substituents.Type: GrantFiled: March 10, 1997Date of Patent: February 16, 1999Assignee: Hoechst AktiengesellschaftInventors: Akihiko Tokida, Wen-Bing Kang, Nu Yu, Thomas Potrawa, Andreas Winterfeldt
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Patent number: 5817727Abstract: The present invention pertains to a film for detecting chemical substances comprising a homopolymer or a copolymer having recurring units represented by the following formula (I): ##STR1## wherein X is --H, --F, --Cl, --Br, --CH.sub.3, --CF.sub.3, --CN or --CH.sub.2 CH.sub.3 ; and R.sup.1 is --R.sup.2 or --Z--R.sup.2 ;wherein Z is --O--, --S--, --NH--, --NR.sup.2' --, --(C.dbd.Y)--, --(C.dbd.Y)--Y--, --Y--(C.dbd.Y)--, --(SO.sub.2)--, --Y'--(SO.sub.2)--, --(SO.sub.2)--Y'--, --Y'--(SO.sub.2)--Y'--, --NH--(C.dbd.O)--, --(C.dbd.O)--NH--, --(C.dbd.O)--NR.sup.2' --, --Y'--(C.dbd.Y)--Y'-- or --O--(C.dbd.O)--(CH.sub.2).sub.n --(C.dbd.O)--O--;wherein Y is independently O or S, and Y' is independently O or NH, and n is an integer of 0 to 20;and wherein R.sup.2 and R.sup.2' represent independently a hydrogen atom, a linear alkyl group, a branched alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated hetero ring or derivatives thereof, provided that R.sup.Type: GrantFiled: June 7, 1995Date of Patent: October 6, 1998Assignee: Hoechst AktiengesellschaftInventors: Werner Prass, Thomas Stehlin, Yuan Liu, Shizuo Ogura, Tetsu Yamamoto, Akihiko Tokida, Kenji Motosugi
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Patent number: 5665844Abstract: The present invention pertains to a film for detecting chemical substances comprising a homopolymer or a copolymer having recurring units represented by the following formula (I): ##STR1## wherein X is --H, --F, --Cl, --Br, --CH.sub.3, --CF.sub.3, --CN or --CH.sub.2 CH.sub.3 ; and R.sup.1 is --R.sup.2 or --Z--R.sup.2 ;wherein Z is --O--, --S--, --NH--, --NR.sup.2' --, --(C.dbd.Y)--, --(C.dbd.Y)--Y--, --Y--(C.dbd.Y)--, --(SO.sub.2)--, --Y'--(SO.sub.2)--, --(SO.sub.2)--Y'--, --Y'--(SO.sub.2)--Y'--, --NH--(C.dbd.O)--, --(C.dbd.O)--NH--, --(C.dbd.O)--NR.sup.2' --, --Y'--(C.dbd.Y)--Y'-- or --O--(C.dbd.O)--(CH.sub.2).sub.n --(C.dbd.O)--O--;wherein Y is independently O or S, and Y' is independently O or NH, and n is an integer of 0 to 20;and wherein R.sup.2 and R.sup.2' represent independently a hydrogen atom, a linear alkyl group, a branched alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated hetero ring or derivatives thereof, provided that R.sup.Type: GrantFiled: November 15, 1993Date of Patent: September 9, 1997Assignee: Hoechst AktiengesellschaftInventors: Werner Prass, Thomas Stehlin, Yuan Liu, Shizuo Ogura, Tetsu Yamamoto, Akihiko Tokida, Kenji Motosugi
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Patent number: 5563707Abstract: An optical sensor for detecting gaseous or liquid chemical species including a sensing element having a flat light reflecting substrate and one or more transparent thin films which are organic or inorganic films or high-polymer films and are formed on the substrate. The detection of the gaseous or liquid chemical species is effected by measuring a change in the light reflection characteristic of the sensing element based on swelling of the thin film or a change in its thickness or refractive index or changes in both parameters.Type: GrantFiled: June 6, 1995Date of Patent: October 8, 1996Assignee: Hoechst AktiengesellschaftInventors: Werner Prass, Thomas Stehlin, Yuan Liu, Shizuo Ogura, Kenji Motosugi, Akihiko Tokida, Tetsu Yamamoto
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Patent number: 5512674Abstract: A process for preparing a titanyl phthalocyanine crystal showing at least one diffraction peak at a Bragg angle (2.theta..+-.0.2) of 27.3.degree. is disclosed, which comprises dissolving or suspending titanyl phthalocyanine in concentrated sulfuric acid to form a solution or a slurry and diluting the solution or slurry with an alcohol solvent, an aromatic solvent, a mixed solvent of an alcohol solvent and water, a mixed solvent of an aromatic solvent and water, or a mixed solvent of an alcohol solvent and an aromatic solvent with or without water thereby to precipitate a crystal, and, if desired, treating the precipitated crystal with an alcohol solvent, an aromatic solvent, a mixed solvent of an alcohol solvent and an aromatic solvent or a mixed solvent of an alcohol solvent and/or an aromatic solvent and water. The resulting titanyl phthalocyanine crystal exhibits high photosensitivity and excellent durability as a photoconductive material of an electrophotographic photoreceptor.Type: GrantFiled: December 6, 1993Date of Patent: April 30, 1996Assignee: Fuji Xerox Co., Ltd.Inventors: Hidemi Nukada, Akihiko Tokida, Yasuo Sakaguchi, Katsumi Daimon, Katsumi Nukada
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Patent number: 5501927Abstract: An electrophotographic photoreceptor including a light-sensitive layer containing a bisazo or trisazo compound represented by formula (I-1), (II-1), (III,1), (IV-1), (V-1) or (VI-1): ##STR1##Type: GrantFiled: June 23, 1993Date of Patent: March 26, 1996Assignee: Fuji Xerox Co., Ltd.Inventors: Akira Imai, Toru Ishii, Akihiko Tokida, Yutaka Akasaki
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Patent number: 5378569Abstract: Oxytitanium phthalocyanine hydrate crystal and an electrophotographic photoreceptor using said crystal are disclosed. The structural formula of the crystal is TiOPc(H.sub.2 O).sub.n wherein Pc represents a phthalocyanine residual group, and n represents from 0.15 to 1; and the elemental analysis values of C, H and N are as follows: C: 65.0 to 66.3 %; H: 2.5 to 3.1 %; and N: 18.5 to 19.3 %.Type: GrantFiled: November 5, 1993Date of Patent: January 3, 1995Assignee: Fuji Xerox Co., Ltd.Inventors: Katsumi Nukada, Katsumi Daimon, Masakazu Iijima, Yasuo Sakaguchi, Hidemi Nukada, Akihiko Tokida
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Patent number: 5298617Abstract: Oxytitanium phthalocyanine hydrate crystal and an electrophotographic photoreceptor using said crystal are disclosed. The structural formula of the crystal is TiOPc(H.sub.2 O).sub.n wherein Pc represents a phthalocyanine residual group, and n represents from 0.15 to 1; and the elemental analysis values of C, H and N are as follows: C: 65.0 to 66.3%; H: 2.5 to 3.1%; and N: 18.5 to 19.3%.Type: GrantFiled: September 10, 1991Date of Patent: March 29, 1994Assignee: Fuji Xerox Co., Ltd.Inventors: Katsumi Nukada, Katsumi Daimon, Masakazu Iijima, Yasuo Sakaguchi, Hidemi Nukada, Akihiko Tokida
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Patent number: 5252417Abstract: A novel titanyl phthalocyanine crystal showing X-ray diffraction peaks at Bragg angles (2.theta..+-.0.2) of 27.2.degree., 24.0.degree., 18.0.degree., 14.3.degree., and 9.5.degree. and an electrophotographic photoreceptor containing the same as a charge generating layer are disclosed. The photoreceptor exhibits high photosensitivity and durability.Type: GrantFiled: March 19, 1991Date of Patent: October 12, 1993Assignee: Fuji Xerox Co., Ltd.Inventors: Akihiko Tokida, Yasuo Sakaguchi, Hidemi Nukada, Kohichi Yamamoto, Katsumi Daimon
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Patent number: 5169987Abstract: A squarylium compound represented by formula (III) ##STR1## wherein R.sub.4 represents a hydrogen atom, a methyl group, or a fluorine atom.Type: GrantFiled: December 7, 1990Date of Patent: December 8, 1992Assignee: Fuji Xerox Co., Ltd.Inventors: Yutaka Akasaki, Akihiko Tokida, Kaoru Torikoshi, Tooru Ishii, Hidemi Suto, Akira Imai
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Patent number: 5047589Abstract: An electrophotographic light-sensitive material comprising a conductive support having formed thereon a light-sensitive layer containing a squarylium compound represented by formula (I) or (II) ##STR1## wherein R.sub.1 represents a hydrogen atom, a methyl group, a carboxy group, a halogen atom, a trifluoromethyl group, an alkyl or phenyl-substituted carbonamido group, or an alkyl- or phenyl-substituted sulfonamido group; X.sub.1 and X.sub.2 each represents a group shown by ##STR2## wherein Z represents an atomic group necessary for forming a ring and R.sub.2 and R.sub.3, each represents an alkyl group having from 1 to 20 carbon atoms, a phenyl group, an unsubstituted benzyl group, or a benzyl group substituted by at least one of an alkyl group having from 1 to 6 carbon atoms, a hydroxy group, an alkoxy group having from 1 to 4 carbon atoms, a halogen atom, a nitro group, a cyano group, an alkoxycarbonyl group having from 2 to 5 carbon atoms, and a trifluoromethyl group); and X.sub.Type: GrantFiled: December 2, 1988Date of Patent: September 10, 1991Assignee: Fuji Xerox Co. Ltd.Inventors: Yutaka Akasaki, Akihiko Tokida, Kaoru Torikoshi, Tooru Ishii, Hidemi Suto, Akira Imai
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Patent number: 5041665Abstract: A process for preparing a squarylium compound useful as a photoconductive material for an electrophotographic photoreceptor, in which process comprises reacting an arylhydroxycyclobutenedione salt or a hydroxycyclobutenedione derivative with an aniline derivative is disclosed. The process comprises dropwise adding a solution of the arylhydroxycyclobutenedione salt or hydroxycyclobutenedione derivative in a solvent, to an alcohol solution of the aniline derivative in an alcohol solvent. An electrophotographic photoreceptor produced by using the thus obtained squarylium compound exhibits and sensitivity, satisfactory chargeability, low dark decay, low residual potential, and excellent stability after repeated use.Type: GrantFiled: December 1, 1988Date of Patent: August 20, 1991Assignee: Fuji Xerox Co., Ltd.Inventors: Yutaka Akasaki, Akihiko Tokida, Kaoru Torikoshi, Akira Imai, Hidemi Suto