Patents by Inventor Takakazu Tanaka

Takakazu Tanaka 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: 7927774
    Abstract: An object of the present invention is to provide an electrophotographic photosensitive member having high durability and hardly causing sensitivity decrease even if short wavelength light, particularly light having a wavelength of 380 to 450 nm is used as exposure light, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. The present invention includes an electrophotographic photosensitive member comprising a support and a photosensitive layer which is provided on the support and contains a charge generation material and a charge transport material, characterized in that the surface layer of the electrophotographic photosensitive member contains an aliphatic dicarboxylic acid polyester resin with a weight average molecular weight of 80,000 or more having a specific repeating structural unit, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
    Type: Grant
    Filed: September 8, 2009
    Date of Patent: April 19, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harunobu Ogaki, Takakazu Tanaka, Kenichi Kaku, Akira Yoshida
  • Publication number: 20090324282
    Abstract: An object of the present invention is to provide an electrophotographic photosensitive member having high durability and hardly causing sensitivity decrease even if short wavelength light, particularly light having a wavelength of 380 to 450 nm is used as exposure light, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. The present invention includes an electrophotographic photosensitive member comprising a support and a photosensitive layer which is provided on the support and contains a charge generation material and a charge transport material, characterized in that the surface layer of the electrophotographic photosensitive member contains an aliphatic dicarboxylic acid polyester resin with a weight average molecular weight of 80,000 or more having a specific repeating structural unit, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
    Type: Application
    Filed: September 8, 2009
    Publication date: December 31, 2009
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Harunobu Ogaki, Takakazu Tanaka, Kenichi Kaku, Akira Yoshida
  • Patent number: 7585604
    Abstract: An object of the present invention is to provide an electrophotographic photosensitive member having high durability and hardly causing sensitivity decrease even if short wavelength light, particularly light having a wavelength of 380 to 450 nm is used as exposure light, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. The present invention includes an electrophotographic photosensitive member comprising a support and a photosensitive layer which is provided on the support and contains a charge generation material and a charge transport material, characterized in that the surface layer of the electrophotographic photosensitive member contains an aliphatic dicarboxylic acid polyester resin with a weight average molecular weight of 80,000 or more having a specific repeating structural unit, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
    Type: Grant
    Filed: September 5, 2005
    Date of Patent: September 8, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harunobu Ogaki, Takakazu Tanaka, Kenichi Kaku, Akira Yoshida
  • Publication number: 20080050664
    Abstract: An object of the present invention is to provide an electrophotographic photosensitive member having high durability and hardly causing sensitivity decrease even if short wavelength light, particularly light having a wavelength of 380 to 450 nm is used as exposure light, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. The present invention includes an electrophotographic photosensitive member comprising a support and a photosensitive layer which is provided on the support and contains a charge generation material and a charge transport material, characterized in that the surface layer of the electrophotographic photosensitive member contains an aliphatic dicarboxylic acid polyester resin with a weight average molecular weight of 80,000 or more having a specific repeating structural unit, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
    Type: Application
    Filed: September 5, 2005
    Publication date: February 28, 2008
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Harunobu Ogaki, Takakazu Tanaka, Kenichi Kaku, Akira Yoshida
  • Patent number: 7045261
    Abstract: In an electrophotographic photosensitive member having a support, and provided thereon a photosensitive layer, a surface layer of the electrophotographic photosensitive member contains a high-molecular-weight charge-transporting material having a weight-average molecular weight Mw of from 1,000 or more to 9,000 or less, and the ratio of the weight-average molecular weight Mw of the high-molecular-weight charge-transporting material to a number-average molecular weight Mn of the high-molecular-weight charge-transporting material, Mw/Mn, is from more than 1.00 to 1.10 or less. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: May 16, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakazu Tanaka, Itaru Takaya, Harunobu Ogaki, Kenichi Kaku
  • Patent number: 7009080
    Abstract: A process for producing a halogenated aromatic amine compound by allowing an aromatic amine compound to react with a dihalogenated aromatic compound in the presence of i) a metallic catalyst having a phosphorus-containing ligand having at least one cyclic hydrocarbon group and ii) a basic compound in a non-reactive solvent.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: March 7, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harunobu Ogaki, Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka
  • Patent number: 7001699
    Abstract: In an electrophotographic photosensitive member having a support, and provided thereon a photosensitive layer, a surface layer of the electrophotographic photosensitive member contains an electrically insulating binder resin and a random-copolymer type high-molecular-weight charge-transporting material having two kinds of specific repeating structural units. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: February 21, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakazu Tanaka, Akira Yoshida, Hidetoshi Hirano, Yuka Ishiduka, Harunobu Ogaki
  • Patent number: 6994941
    Abstract: An electrophotographic photosensitive member is provided having a support and a photosensitive layer provided on the support and containing at least one kind of charge-transporting material which has a specific structure with a molecular weight of from 1,500 to 4,000, and is held in a proportion of from 90% by weight to 100% by weight based on the total weight of the charge-transporting material.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: February 7, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka, Harunobu Ogaki, Kenichi Kaku
  • Patent number: 6991881
    Abstract: The present invention relates to an electrophotographic photosensitive member having a support and provided thereon a photosensitive layer. The photosensitive layer contains a high-molecular weight charge-transporting material having a specific repeating structural unit. The high-molecular weight charge-transporting material has a weight-average molecular weight Mw of 1,500 or more and an energy level of highest occupied molecular orbital, EHOMO, of from ?8.3 eV or more to ?8.0 eV or less as found by semiempirical molecular-orbital calculation. The present invention also relates to a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
    Type: Grant
    Filed: April 25, 2003
    Date of Patent: January 31, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Harunobu Ogaki, Akira Yoshida, Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka
  • Patent number: 6958204
    Abstract: An electrophotographic photosensitive member includes a charge generating material and a charge transfer material. The charge transfer material contains a triarylamine compound synthesized from an amine compound and an aryl halide in the presence of a catalyst comprising a phosphine compound represented by formula (1) and a palladium compound: wherein Ar1 to Ar3 are each independently an alkyl or aryl group which may have a substituent group, and at least one of Ar1 to Ar3 is an aryl group. A process cartridge includes the electrophotographic photosensitive member.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: October 25, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakazu Tanaka, Mitsuhiro Kunieda, Yuka Nakajima, Harunobu Ohgaki
  • Publication number: 20050208402
    Abstract: An electrophotographic photosensitive member is provided having a support and a photosensitive layer provided on the support and containing at least one kind of charge-transporting material which has a specific structure with a molecular weight of from 1,500 to 4,000, and is held in a proportion of from 90% by weight to 100% by weight based on the total weight of the charge-transporting material.
    Type: Application
    Filed: May 16, 2005
    Publication date: September 22, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka, Harunobu Ogaki, Kenichi Kaku
  • Publication number: 20050100805
    Abstract: An electrophotographic photosensitive member is provided having a support and a photosensitive layer provided on the support and containing at least one kind of charge-transporting material which has a specific structure with a molecular weight of from 1,500 to 4,000, and is held in a proportion of from 90% by weight to 100% by weight based on the total weight of the charge-transporting material.
    Type: Application
    Filed: August 28, 2003
    Publication date: May 12, 2005
    Inventors: Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka, Harunobu Ogaki, Kenichi Kaku
  • Publication number: 20050026059
    Abstract: An electrophotographic photosensitive member includes a charge generating material and a charge transfer material. The charge transfer material contains a triarylamine compound synthesized from an amine compound and an aryl halide in the presence of a catalyst comprising a phosphine compound represented by formula (1) and a palladium compound: wherein Ar1 to Ar3 are each independently an alkyl or aryl group which may have a substituent group, and at least one of Ar1 to Ar3 is an aryl group. A process cartridge includes the electrophotographic photosensitive member.
    Type: Application
    Filed: August 25, 2004
    Publication date: February 3, 2005
    Inventors: Takakazu Tanaka, Mitsuhiro Kunieda, Yuka Nakajima, Harunobu Ohgaki
  • Patent number: 6818368
    Abstract: An electrophotographic photosensitive member includes a charge generating material and a charge transfer material. The charge transfer material contains a triarylamine compound synthesized from an amine compound and an aryl halide in the presence of a catalyst comprising a phosphine compound represented by formula (1) and a palladium compound: wherein Ar1 to Ar3 are each independently an alkyl or aryl group which may have a substituent group, and at least one of Ar1 to Ar3 is an aryl group. A process cartridge includes the electrophotographic photosensitive member.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: November 16, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakazu Tanaka, Mitsuhiro Kunieda, Yuka Nakajima, Harunobu Ohgaki
  • Publication number: 20040127716
    Abstract: A process for producing a halogenated aromatic amine compound by allowing an aromatic amine compound to react with a dihalogenated aromatic compound in the presence of i) a metallic catalyst having a phosphorus-containing ligand having at least one cyclic hydrocarbon group and ii) a basic compound in a non-reactive solvent.
    Type: Application
    Filed: September 29, 2003
    Publication date: July 1, 2004
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Harunobu Ogaki, Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka
  • Publication number: 20040053150
    Abstract: In an electrophotographic photosensitive member having a support, and provided thereon a photosensitive layer, a surface layer of the electrophotographic photosensitive member contains an electrically insulating binder resin and a random-copolymer type high-molecular-weight charge-transporting material having two kinds of specific repeating structural units. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 18, 2004
    Inventors: Takakazu Tanaka, Akira Yoshida, Hidetoshi Hirano, Yuka Ishiduka, Harunobu Ogaki
  • Publication number: 20040048179
    Abstract: In an electrophotographic photosensitive member having a support, and provided thereon a photosensitive layer, a surface layer of the electrophotographic photosensitive member contains a high-molecular-weight charge-transporting material having a weight-average molecular weight Mw of from 1,000 or more to 9,000 or less, and the ratio of the weight-average molecular weight Mw of the high-molecular-weight charge-transporting material to a number-average molecular weight Mn of the high-molecular-weight charge-transporting material, Mw/Mn, is from more than 1.00 to 1.10 or less. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 11, 2004
    Inventors: Takakazu Tanaka, Itaru Takaya, Harunobu Ogaki, Kenichi Kaku
  • Publication number: 20030232263
    Abstract: The present invention relates to an electrophotographic photosensitive member having a support and provided thereon a photosensitive layer. The photosensitive layer contains a high-molecular weight charge-transporting material having a specific repeating structural unit. The high-molecular weight charge-transporting material has a weight-average molecular weight Mw of 1,500 or more and an energy level of highest occupied molecular orbital, EHOMO, of from −8.3 eV or more to −8.0 eV or less as found by semiempirical molecular-orbital calculation. The present invention also relates to a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.
    Type: Application
    Filed: April 25, 2003
    Publication date: December 18, 2003
    Inventors: Harunobu Ogaki, Akira Yoshida, Takakazu Tanaka, Itaru Takaya, Yuka Ishiduka
  • Patent number: 6410195
    Abstract: An electrophotographic photosensitive member comprising a support and a photosensitive layer provided thereon. The photosensitive layer fulfilling at least one of the following conditions (A) and (B): (A) containing a polymerization product of a monomer having a reactive group represented by the following Formula (1): —O—(—CH2—)n—CH═CH—R0  (1);  and (B) containing a copolymerization product of a monomer having a reactive group represented by the following Formula (2): —O—CH═CH2  (2) with a charge-transporting material having a reactive group capable of reacting with the monomer.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: June 25, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takakazu Tanaka, Yuka Nakajima
  • Publication number: 20020048710
    Abstract: An electrophotographic photosensitive member includes a charge generating material and a charge transfer material.
    Type: Application
    Filed: April 12, 2001
    Publication date: April 25, 2002
    Inventors: Takakazu Tanaka, Mitsuhiro Kunieda, Yuka Nakajima, Harunobu Ohgaki