Patents by Inventor Katsuhisa Yamazaki

Katsuhisa Yamazaki 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).

  • Publication number: 20040043315
    Abstract: To provide a toner which exhibits excellent performances for image characteristics, and also has excellent performances for charging property even if the toner is used in a cleaning simultaneous with developing system having a direct injection charging mechanism. The toner of the present invention comprises toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 &mgr;m to 12.0 &mgr;m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 &mgr;m to 4.0 &mgr;m with respect to a volume-basis particle diameter distribution, the medium diameter (D50) being smaller than a weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 &mgr;m or less with respect to a volume-basis particle diameter.
    Type: Application
    Filed: April 18, 2003
    Publication date: March 4, 2004
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tsuyoshi Takiguchi, Yosuke Morikawa, Takashige Kasuya, Kimihiro Yoshimura, Katsuhisa Yamazaki, Kaori Hiratsuka
  • Publication number: 20040005509
    Abstract: In a toner having a polyester resin as a binder resin component, and a colorant, the toner contains (a) in the binder resin component, from 20.0% by weight to 65.0% by weight of a tetrahydrofuran-insoluble matter A1 in 6-hour extraction and from 35.0% by weight to 80.0% by weight of a tetrahydrofuran-soluble matter A2 in 6-hour extraction, (b) in the binder resin component, from 10.0% by weight to 30.0% by weight of a tetrahydrofuran-insoluble matter B1 in 16-hour extraction and from 70.0% by weight to 90.0% by weight of a tetrahydrofuran-soluble matter B2 in 16-hour extraction, and (c) in the binder resin component, from 0.5% by weight to 3.0% by weight of an orthodichloro- benzene-insoluble matter C1 in 6-hour extraction at 185° C. and from 97.0% by weight to 99.5% by weight of an orthodichlorobenzene-soluble matter C2 in 6-hour extraction at 185° C. The proportion of C1 to B1, C1/B1, is from 0.06 to 0.
    Type: Application
    Filed: March 20, 2003
    Publication date: January 8, 2004
    Inventors: Shuhei Moribe, Hirohide Tanikawa, Hiroshi Yusa, Takashige Kasuya, Yoshihiro Ogawa, Hideto Iida, Katsuhisa Yamazaki
  • Patent number: 6589701
    Abstract: A dry magnetic toner is formed of magnetic toner particles comprising a binder resin and magnetic iron oxide particles. The magnetic toner is provided with excellent developing performances and transferability by controlling the presence of isolated iron-containing particles and containing a high percentage of spherical particles, the amount of which is controlled relative to the weight-average particle size of the magnetic toner and a content of particles of 3 &mgr;m or below in the magnetic toner.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: July 8, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsuhisa Yamazaki, Tsutomu Onuma, Nobuyuki Okubo, Tsuneo Nakanishi, Kaori Hiratsuka
  • Patent number: 6586151
    Abstract: A toner manufacturing method includes grinding and classification to produce a toner containing a binder resin and a colorant with a weight mean particle size of 5 microns to 12 microns and sharp particle density distribution. The toner has a specific circularity, relationship between cut ratio and weight mean size, and relationship between circularity and weight mean size as disclosed in the specification.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: July 1, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Naka, Yuichi Mizoo, Satoshi Matsunaga, Masami Azuma, Takashige Kasuya, Tadashi Dojo, Tsuneo Nakanishi, Nene Shibayama, Katsuhisa Yamazaki, Yusuke Hasegawa
  • Patent number: 6537715
    Abstract: A toner has toner particles containing at least a binder resin, a colorant and a sulfur-containing compound selected from the group consisting of a sulfur-containing polymer and a sulfur-containing copolymer. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or larger in diameter, at least 90% by number of particles with a circularity of 0.900 or higher, and has a specific relationship between the cut rate Z and the toner weight-average particle diameter X and a specific relationship between the number-based cumulative value Y of particles with a circularity of 0.950 or higher and the toner weight-average particle diameter X. Also disclosed are an image-forming method and a process cartridge which make use of the toner.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: March 25, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuichi Mizoo, Takeshi Naka, Masami Azuma, Takashige Kasuya, Tadashi Dojo, Tsuneo Nakanishi, Nene Shibayama, Katsuhisa Yamazaki, Yusuke Hasegawa
  • Publication number: 20030054278
    Abstract: A toner contains at least a bonding resin and a coloring agent, and has the following characteristics (i) to (iv):
    Type: Application
    Filed: May 23, 2002
    Publication date: March 20, 2003
    Inventors: Takeshi Naka, Yuichi Mizoo, Satoshi Matsunaga, Masami Azuma, Takashige Kasuya, Tadashi Dojo, Tsuneo Nakanishi, Nene Shibayama, Katsuhisa Yamazaki, Yusuke Hasegawa
  • Publication number: 20030036008
    Abstract: A toner showing a high transferability and suitable for use in cleanerless image forming system is formed of toner particles comprising at least a binder resin and magnetic iron oxide. The toner is characterized by a specific circularity distribution relative to its weight-average particle size and a controlled degree of surface-exposed magnetic iron oxide providing an extract solution with hydrochloric acid showing an absorbance of 1.0-2.5 at a wavelength of 340 nm. The toner is suitably produced by a production system including a rotary mechanical pulverizer and a one-pass surface treatment apparatus for continuously applying a mechanical impact force to pulverized toner particles therein.
    Type: Application
    Filed: April 8, 2002
    Publication date: February 20, 2003
    Inventors: Katsuhisa Yamazaki, Hirohide Tanikawa, Hiroshi Yusa, Takashige Kasuya, Yoshihiro Ogawa, Shuhei Moribe
  • Patent number: 6458499
    Abstract: A toner is principally constituted by a binder resin, a colorant and a hydrocarbon wax. The hydrocarbon wax has a hydroxyl value (Hv) of 5-150 mgKOH/g and an ester value (Ev) of 1-50 mgKOH/g satisfying Hv>Ev. Further, the toner has a tetrahydrofuran-soluble content providing a gel-permeation chromatogram showing at least one peak in a molecular weight region of 3×103 to 5×104 and at least one peak or shoulder in a molecular weight region of 1×105 to 1×107.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: October 1, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Onuma, Hirohide Tanikawa, Nobuyuki Okubo, Tsuneo Nakanishi, Katsuhisa Yamazaki, Kaori Hiratsuka
  • Patent number: 6426169
    Abstract: A toner having a stable chargeability in various environments, a stable fixability over a wide temperature range and a resistance to sticking on an image-bearing member, is formed of a binder resin, a colorant and an azo iron compound as a charge control agent. The azo iron compound is formed from a monoazo compound having at least one alkyl group and two hydroxyl groups capable of bonding with an iron atom. The toner has a tetrahydrofuran-soluble content providing a gel-permeation chromatogram showing at least one peak in a molecular weight region of 3×103 to 5×104 and at least one peak or shoulder in a molecular weight region of above 5×104 and at most 1×107.
    Type: Grant
    Filed: October 30, 2000
    Date of Patent: July 30, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Onuma, Hirohide Tanikawa, Nobuyuki Okubo, Yoshihiro Ogawa, Tsuneo Nakanishi, Katsuhisa Yamazaki, Kaori Hiratsuka
  • Publication number: 20020072006
    Abstract: A toner has toner particles containing at least a binder resin, a colorant and a sulfur-containing compound selected from the group consisting of a sulfur-containing polymer and a sulfur-containing copolymer. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or larger in diameter, at least 90% by number of particles with a circularity of 0.900 or higher, and has a specific relationship between the cut rate Z and the toner weight-average particle diameter X and a specific relationship between the number-based cumulative value Y of particles with a circularity of 0.950 or higher and the toner weight-average particle diameter X. Also disclosed are an image-forming method and a process cartridge which make use of the toner.
    Type: Application
    Filed: July 26, 2001
    Publication date: June 13, 2002
    Inventors: Yuichi Mizoo, Takeshi Naka, Masami Azuma, Takashige Kasuya, Tadashi Dojo, Tsuneo Nakanishi, Nene Shibayama, Katsuhisa Yamazaki, Yusuke Hasegawa
  • Publication number: 20020055053
    Abstract: A toner showing quick chargeability and stable chargeability in a high humidity environment is provided by a combination of a specific polyester binder resin and a specific azo iron compound. The polyester binder resin has an acid value (Av) of 0.5 to 30 mgKOH/g and a hydroxyl value (OHv) of 1 to 50 mgKOH/g giving a ratio (Av/OHv) therebetween satisfying: 0.05≦Av/OHv≦2.0. The azo iron compound is preferably an iron complex (salt) including as a ligand a mono-azo compound formed by diazo coupling between a 2-aminophenol (derivative) and an alkyl-substituted naphthol (derivative).
    Type: Application
    Filed: September 6, 2001
    Publication date: May 9, 2002
    Inventors: Takashige Kasuya, Hirohide Tanikawa, Hiroshi Yusa, Yoshihiro Ogawa, Katsuhisa Yamazaki, Ryota Kashiwabara
  • Publication number: 20020051922
    Abstract: A dry magnetic toner is formed of magnetic toner particles comprising a binder resin and magnetic iron oxide particles. The magnetic toner is provided with excellent developing performances and transferability by controlling the presence of isolated iron-containing particles and containing a high percentage of spherical particles, the amount of which is controlled relative to the weight-average particle size of the magnetic toner and a content of particles of 3 &mgr;m or below in the magnetic toner.
    Type: Application
    Filed: July 25, 2001
    Publication date: May 2, 2002
    Inventors: Katsuhisa Yamazaki, Tsutomu Onuma, Nobuyuki Okubo, Tsuneo Nakanishi, Kaori Hiratsuka
  • Publication number: 20020034702
    Abstract: A toner is principally constituted by a binder resin, a colorant and a hydrocarbon wax. The hydrocarbon wax has a hydroxyl value (Hv) of 5-150 mgKOH/g and an ester value (Ev) of 1-50 mgKOH/g satisfying Hv>Ev. Further, the toner has a tetrahydrofuran-soluble content providing a gel-permeation chromatogram showing at least one peak in a molecular weight region of 3×103 to 5×104 and at least one peak or shoulder in a molecular weight region of 1×105 to 1×107.
    Type: Application
    Filed: June 1, 2001
    Publication date: March 21, 2002
    Inventors: Tsutomu Onuma, Hirohide Tanikawa, Nobuyuki Okubo, Tsuneo Nakanishi, Katsuhisa Yamazaki, Kaori Hiratsuka