Patents by Inventor Nobuhiro Miyakawa

Nobuhiro Miyakawa 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: 7955770
    Abstract: The surface of a photoconductor is coated with a surface protection layer comprising a cured material of a fluorine-containing photo-curing composition containing fluorinated alkyl group-containing (meth)acrylate and a photopolymerization initiator, and the surface protection layer has a fluorine atom content of 8.5 to 20% by mass.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: June 7, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Shinji Yasukawa, Tomotake Hiraga, Ken Ikuma
  • Patent number: 7809295
    Abstract: A color image forming apparatus includes, for each of liquid developers of plural colors, a photosensitive member, a developing roller, an agitating device that agitates a liquid developer having a viscosity characteristic dependent on a shearing force, and a developer supplying unit that supplies the liquid developer to the developing roller. In development, agitation start timing is varied depending on the color of the liquid developer.
    Type: Grant
    Filed: October 19, 2007
    Date of Patent: October 5, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Shinji Yasukawa, Nobuhiro Miyakawa, Ken Ikuma
  • Patent number: 7723005
    Abstract: A liquid developer contains an insulation liquid containing as its main component a glyceride of an unsaturated fatty acid, toner particles dispersed in the insulation liquid; and an oxidation polymerization accelerator for accelerating oxidation polymerization reaction of the glyceride during fixing process of the toner particles. The oxidation polymerization accelerator accelerates the oxidation polymerization reaction by supplying oxygen during the fixing process of the toner particles. The liquid developer may further contain an antioxidizing agent. Preferably, the oxidation polymerization accelerator is contained in the insulation liquid being encapsulated.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: May 25, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Koji Akioka, Nobuhiro Miyakawa, Takashi Teshima, Satoru Miura
  • Patent number: 7608375
    Abstract: A liquid developer includes a positively chargeable pigment, a carrier liquid formed of a vegetable oil, and an antioxidant formed of a phosphorous acid ester compound.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: October 27, 2009
    Assignee: Seiko Epson Corporation
    Inventor: Nobuhiro Miyakawa
  • Patent number: 7529503
    Abstract: The present invention provides a toner having: a toner mother particle; a first external additive including a first inorganic fine particle having a primary particle size distribution of 200 to 750 nm and a work function approximately equivalent to that of the toner mother particle; a second external additive including a second inorganic fine particle having an mean particle size smaller than that of the first inorganic fine particle and a work function smaller than that of the toner particle, a stirring member of a developing device and/or an inner wall of the developing device; and 0.01% to 0.3% by weight of a metal soap having a work function approximately equivalent to that of the toner mother particle.
    Type: Grant
    Filed: March 13, 2008
    Date of Patent: May 5, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Shinji Yasukawa, Hiroyuki Murakami
  • Publication number: 20080220354
    Abstract: The surface of a photoconductor is coated with a surface protection layer comprising a cured material of a fluorine-containing photo-curing composition containing fluorinated alkyl group-containing (meth)acrylate and a photopolymerization initiator, and the surface protection layer has a fluorine atom content of 8.5 to 20% by mass.
    Type: Application
    Filed: October 16, 2007
    Publication date: September 11, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Nobuhiro MIYAKAWA, Shinji YASUKAWA, Tomotake HIRAGA
  • Publication number: 20080176163
    Abstract: The present invention provides a toner having: a toner mother particle; a first external additive including a first inorganic fine particle having a primary particle size distribution of 200 to 750 nm and a work function approximately equivalent to that of the toner mother particle; a second external additive including a second inorganic fine particle having an mean particle size smaller than that of the first inorganic fine particle and a work function smaller than that of the toner particle, a stirring member of a developing device and/or an inner wall of the developing device; and 0.01% to 0.3% by weight of a metal soap having a work function approximately equivalent to that of the toner mother particle.
    Type: Application
    Filed: March 13, 2008
    Publication date: July 24, 2008
    Applicant: Seiko Epson Corporation
    Inventors: Nobuhiro MIYAKAWA, Shinji Yasukawa, Hiroyuki Murakami
  • Patent number: 7390603
    Abstract: The present invention provides An image forming apparatus having: a negatively chargeable spherical toner; an latent image carrier; a charging member for charging a surface of the latent image carrier uniformly without contacting the latent image carrier; an electrostatic latent image forming member for forming an electrostatic latent image on the surface of the latent image carrier; a developing member for developing the electrostatic latent image, without contacting the latent image carrier, by using the negatively chargeable spherical toner so as to form a toner image on the latent image carrier; and an intermediate transfer medium to which the toner image is transferred, wherein the negatively chargeable spherical toner haves: a toner mother particle having a binder resin and a colorant; and a hydrophobic alumina particle as an external additive, wherein the hydrophobic alumina particle has a work function (?A1) larger than a work function (?TM) of a surface of the intermediate transfer medium.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: June 24, 2008
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Toshiaki Yamagami, Satoshi Chiba
  • Patent number: 7390604
    Abstract: The present invention provides a negatively chargeable spherical toner having: a toner mother particle having a binder resin and a colorant, which has: a number average particle size of from 4.5 to 9 ?m; a particle size distribution that has an integrated value of particle sizes of 3 ?m or less of 1% or less; and an average sphericity of from 0.95 to 0.99; and an alumina fine particle externally added to the toner mother particle, which has a number average particle size of from 0.1 to 1.0 ?m, wherein a work function (?t) of the toner mother particle is larger than a work function (?A) of the alumina fine particle by at least 0.4 eV.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: June 24, 2008
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Toshiaki Yamagami, Ken Ikuma
  • Publication number: 20080138101
    Abstract: A color image forming apparatus includes, for each of liquid developers of plural colors, a photosensitive member, a developing roller, an agitating device that agitates a liquid developer having a viscosity characteristic dependent on a shearing force, and a developer supplying unit that supplies the liquid developer to the developing roller. In development, agitation start timing is varied depending on the color of the liquid developer.
    Type: Application
    Filed: October 19, 2007
    Publication date: June 12, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Shinji YASUKAWA, Nobuhiro MIYAKAWA, Ken IKUMA
  • Patent number: 7356281
    Abstract: The present invention provides a toner having: a toner mother particle; a first external additive including a first inorganic fine particle having a primary particle size distribution of 200 to 750 nm and a work function approximately equivalent to that of the toner mother particle; a second external additive including a second inorganic fine particle having an mean particle size smaller than that of the first inorganic fine particle and a work function smaller than that of the toner particle, a stirring member of a developing device and/or an inner wall of the developing device; and 0.01% to 0.3% by weight of a metal soap having a work function approximately equivalent to that of the toner mother particle.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: April 8, 2008
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Shinji Yasukawa, Hiroyuki Murakami
  • Publication number: 20080008953
    Abstract: A liquid developer includes a vegetable oil as a carrier liquid, a positively chargeable pigment and an antioxidant including a trialkyl phosphite represented by the chemical formula 1 and/or a diphenyl alkyl phosphite represented by the chemical formula 2: (CmH2m+1O)3PChemical formula 1 wherein m is 2 to 20, wherein n is 5 to 15.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 10, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Nobuhiro MIYAKAWA, Shinji YASUKAWA
  • Patent number: 7309554
    Abstract: A negatively chargeable toner containing: resin particles containing a colorant; and an external additive which coats the surface of the resin particles, wherein the external additive contains; first silica particles having a number mean primary particle size of 5 to 20 nm and second silica particles having a number mean primary particle size of 30 to 50 nm; surface-modified silica particles which are surface modified by wet treatment using an oxide or hydroxide of at least one metal selected from the group consisting of titanium, tin, zirconium and aluminum, and are further subjected to hydrophobic treatment; and aluminum oxide-silicon dioxide composite oxide particles obtained by flame hydrolysis and hydrophobic treatment.
    Type: Grant
    Filed: July 15, 2004
    Date of Patent: December 18, 2007
    Assignee: Seiko Epson Corporation
    Inventor: Nobuhiro Miyakawa
  • Patent number: 7306885
    Abstract: The present invention provides toners of different colors in which coloring agents of at least four unicolors are internally added to, respectively, and hydrophobic silica particles and metallic soap particles are externally added to toner mother particles, wherein color superposition of the toners is conducted during development of latent images on a latent image carrier or during transfer to a recording medium after the development, being characterized in that the difference (absolute value) between the work functions of two of said toners is 0.02 eV or more, the color superposition is conducted with the toners sequentially from the toner having the largest work function in descending order of work function of the toners, and the difference (absolute value) between the work function of the toner mother particles and the work function of the metallic soap particles is 0.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: December 11, 2007
    Assignee: Seiko Epson Corporation
    Inventor: Nobuhiro Miyakawa
  • Publication number: 20070141504
    Abstract: The invention provides a liquid developer using a vegetable oil as a carrier solution, wherein a coloring agent for the carrier solution includes a benzimidazole pigment represented by chemical formula 1 and is positively chargeable. Here R1 is OCH3, COOCH3 or COOC4H9(n), R2 is NO2, H, CONHC6H5 or SO2NHR where R is an alkyl group represented by CnH2n+1 provided that n is an integer of 1 to 4, and R3 is H, CH3 or OCH3.
    Type: Application
    Filed: June 5, 2006
    Publication date: June 21, 2007
    Inventor: Nobuhiro Miyakawa
  • Publication number: 20070128535
    Abstract: A liquid developer includes a positively chargeable pigment, a carrier liquid formed of a vegetable oil, and an antioxidant formed of a phosphorous acid ester compound.
    Type: Application
    Filed: December 1, 2006
    Publication date: June 7, 2007
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobuhiro MIYAKAWA
  • Publication number: 20070128534
    Abstract: A liquid developer includes a vegetable oil, a positively chargeable pigment, and a phosphorous acid ester compound.
    Type: Application
    Filed: December 1, 2006
    Publication date: June 7, 2007
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobuhiro MIYAKAWA
  • Publication number: 20070128536
    Abstract: A liquid developer includes a carrier liquid formed of a vegetable oil containing a positively chargeable pigment, wherein the liquid developer contains an antioxidant formed of a phosphorus acid ester compound and contains 10% to 60% by mass of triglyceridic linolenic acid component in the carrier liquid.
    Type: Application
    Filed: December 5, 2006
    Publication date: June 7, 2007
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobuhiro MIYAKAWA
  • Patent number: 7217486
    Abstract: The present invention provides a toner containing toner mother particles containing a binder resin and a colorant having added thereinto external additives, e.g., positively electrifiable silica fine particles, negatively electrifiable silica fine particles, titanium oxide fine particles and a long chain fatty acid or a salt thereof, wherein the external additives are added by multistage process, thereby is low in desorption of external additives, has the electrification property for a long period of time, shows high flowability and transfer efficiency, and is not accompanied by the reduction of image density.
    Type: Grant
    Filed: January 16, 2004
    Date of Patent: May 15, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Hiroshi Kato, Nobuhiro Miyakawa
  • Patent number: 7190928
    Abstract: The invention provides an image-forming apparatus comprising: at least one latent image holding member on which an electrostatic latent image is to be formed; developing devices having toners of different colors for developing the electrostatic latent image on the latent image holding member to form a toner image; and an intermediate transfer medium onto which the thus formed toner image is to be transferred, wherein the intermediate transfer medium has a work function smaller than or equal to the work function of each of the toners.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: March 13, 2007
    Assignee: Seiko Epson Corporation
    Inventors: Nobuhiro Miyakawa, Mikio Furumizu