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).

  • Patent number: 6559473
    Abstract: 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 wherei
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: May 6, 2003
    Assignee: Hoechst Japan Limited
    Inventors: Nu Yu, Wen-Bing Kang, Akihiko Tokida
  • Patent number: 6361917
    Abstract: 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: Grant
    Filed: July 22, 1996
    Date of Patent: March 26, 2002
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wen-Bing Kang, Nu Yu, Akihiko Tokida
  • Patent number: 6232466
    Abstract: 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: Grant
    Filed: March 19, 1991
    Date of Patent: May 15, 2001
    Assignee: Fuji Xerox Co., LTD
    Inventors: Katsumi Daimon, Akihiko Tokida, Katsumi Nukada, Hidemi Nukada, Yasuo Sakaguchi
  • Patent number: 6184305
    Abstract: 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: Grant
    Filed: May 15, 1998
    Date of Patent: February 6, 2001
    Assignee: Clariant Finance (BVI) Limited
    Inventors: Wen-Bing Kan, Akihiko Tokida, Kayo Aramaki, Hatsuyuki Tanaka, Ken Kimura
  • Patent number: 5919579
    Abstract: 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: Grant
    Filed: January 17, 1997
    Date of Patent: July 6, 1999
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wen-Bing Kang, Nu Yu, Akihiko Tokida, Thomas Potrawa, Andreas Winterfeldt
  • Patent number: 5871854
    Abstract: 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: Grant
    Filed: March 10, 1997
    Date of Patent: February 16, 1999
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Akihiko Tokida, Wen-Bing Kang, Nu Yu, Thomas Potrawa, Andreas Winterfeldt
  • Patent number: 5817727
    Abstract: 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: Grant
    Filed: June 7, 1995
    Date of Patent: October 6, 1998
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Werner Prass, Thomas Stehlin, Yuan Liu, Shizuo Ogura, Tetsu Yamamoto, Akihiko Tokida, Kenji Motosugi
  • Patent number: 5665844
    Abstract: 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: Grant
    Filed: November 15, 1993
    Date of Patent: September 9, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Werner Prass, Thomas Stehlin, Yuan Liu, Shizuo Ogura, Tetsu Yamamoto, Akihiko Tokida, Kenji Motosugi
  • Patent number: 5563707
    Abstract: 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: Grant
    Filed: June 6, 1995
    Date of Patent: October 8, 1996
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Werner Prass, Thomas Stehlin, Yuan Liu, Shizuo Ogura, Kenji Motosugi, Akihiko Tokida, Tetsu Yamamoto
  • Patent number: 5512674
    Abstract: 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: Grant
    Filed: December 6, 1993
    Date of Patent: April 30, 1996
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Hidemi Nukada, Akihiko Tokida, Yasuo Sakaguchi, Katsumi Daimon, Katsumi Nukada
  • Patent number: 5501927
    Abstract: 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: Grant
    Filed: June 23, 1993
    Date of Patent: March 26, 1996
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akira Imai, Toru Ishii, Akihiko Tokida, Yutaka Akasaki
  • Patent number: 5378569
    Abstract: 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: Grant
    Filed: November 5, 1993
    Date of Patent: January 3, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Katsumi Daimon, Masakazu Iijima, Yasuo Sakaguchi, Hidemi Nukada, Akihiko Tokida
  • Patent number: 5298617
    Abstract: 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: Grant
    Filed: September 10, 1991
    Date of Patent: March 29, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Katsumi Daimon, Masakazu Iijima, Yasuo Sakaguchi, Hidemi Nukada, Akihiko Tokida
  • Patent number: 5252417
    Abstract: 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: Grant
    Filed: March 19, 1991
    Date of Patent: October 12, 1993
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akihiko Tokida, Yasuo Sakaguchi, Hidemi Nukada, Kohichi Yamamoto, Katsumi Daimon
  • Patent number: 5169987
    Abstract: A squarylium compound represented by formula (III) ##STR1## wherein R.sub.4 represents a hydrogen atom, a methyl group, or a fluorine atom.
    Type: Grant
    Filed: December 7, 1990
    Date of Patent: December 8, 1992
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yutaka Akasaki, Akihiko Tokida, Kaoru Torikoshi, Tooru Ishii, Hidemi Suto, Akira Imai
  • Patent number: 5047589
    Abstract: 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: Grant
    Filed: December 2, 1988
    Date of Patent: September 10, 1991
    Assignee: Fuji Xerox Co. Ltd.
    Inventors: Yutaka Akasaki, Akihiko Tokida, Kaoru Torikoshi, Tooru Ishii, Hidemi Suto, Akira Imai
  • Patent number: 5041665
    Abstract: 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: Grant
    Filed: December 1, 1988
    Date of Patent: August 20, 1991
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yutaka Akasaki, Akihiko Tokida, Kaoru Torikoshi, Akira Imai, Hidemi Suto