Identified Magnetic Toner Patents (Class 430/122.5)
  • Patent number: 9250551
    Abstract: An electrostatic latent image developing toner is manufactured by mixing an aqueous medium dispersion liquid (X) containing negatively chargeable toner cores and an aqueous medium dispersion liquid (Y) containing positively chargeable resin particulates, followed by stirring the mixture liquid to form shell layers each on a surface of the toner cores with the resin particulates. The shell layers are formed with the resin particulates subjected to a stirring treatment together with an anionic surfactant.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: February 2, 2016
    Assignee: KYOCERA Document Solutions Inc.
    Inventors: Seishi Ojima, Ryotaro Komada
  • Patent number: 9116460
    Abstract: An image forming apparatus includes a latent image forming device that forms a latent image, a latent image carrier that carries the latent image, a development device that develops the latent image, and a controller. The development device includes a developer carrier that faces the latent image carrier and carries toner on a rotary surface thereof that rotates in a rotation direction perpendicular to a width direction of the developer carrier, and a regulation member that regulates the thickness of a layer of the toner on the surface of the developer carrier. The controller moves the toner on lateral end regions in the width direction of the surface of the developer carrier toward the latent image carrier. The end regions are located outside a maximum image forming region within a regulation member facing region of the surface of the developer carrier facing the regulation member.
    Type: Grant
    Filed: November 27, 2013
    Date of Patent: August 25, 2015
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasuhide Matsuno, Naoki Nakatake, Yuji Nagatomo, Takahiro Sanada
  • Patent number: 8507170
    Abstract: An image-forming method includes forming an electrostatic image on an electrostatic image bearing member which has been charged; developing the electrostatic image to form a toner image; transferring the toner image on the electrostatic image bearing member with or without mediating an intermediate transferring member onto a transfer material; and fixing the toner image on the transfer material. The electrostatic image bearing member is a photosensitive member obtained by sequentially laminating a photoconductive layer and a surface layer formed of hydrogenated amorphous silicon carbide, and a sum of an atomic density of silicon atoms and an atomic density of carbon atoms in the surface layer of the photosensitive member is 6.60×1022 atoms/cm3 or more. The toner has a binder resin and magnetic iron oxide particles, and the magnetic iron oxide particles contain Fe(2+) at a content of 20.0 mass % or more and 25.0 mass % or less.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: August 13, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tooru Takahashi, Katsuhisa Yamazaki, Syuhei Moribe, Daisuke Yoshiba, Masami Fujimoto
  • Patent number: 8247150
    Abstract: A carrier for developing an electrostatic latent image which includes a core material and a resin coating layer provided on the core material. The resin coating layer includes a resin and a particulate tin oxide, and the surface of the particulate tin oxide is coated with carbon.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: August 21, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata
  • Patent number: 7862977
    Abstract: A method to form an image using a trickle developing system, wherein (a) the toner comprises colorant particles with a volume median diameter of 3 to 8 ?m having first inorganic particles on surfaces of the colorant particles to form toner particles; (b) the carrier comprises magnetic particles with a weight average particle diameter (D4) of 20 to 40 ?m having second inorganic particles on surfaces of the magnetic particles to form carrier particles; and (c) an area ratio of element (A) based on a total area of surfaces of the carrier particles is 0.5 to 3.0 area % determined by using an X-ray analysis, provided that element (A) represents one or more elements commonly contained in the first inorganic particles and in the second inorganic particles.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: January 4, 2011
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventors: Makoto Kobayashi, Yoshiyasu Matsumoto
  • Patent number: 7682765
    Abstract: To provide a toner for developing electrostatic images which is not easily cause the phenomenon of toner-spent, constituent materials are so selected that a charge control resin has hardness which is the same as the hardness of a binder resin or the charge control resin is harder than the binder resin, as measured with a scanning probe microscope in a viscoelasticity evaluation mode in respect to the binder resin and the charge control resin which are present in the particle interiors or particle surfaces of the toner.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: March 23, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Etsuko Sugawa, Chieko Mihara, Takashi Kenmoku, Tatsuki Fukui, Shinya Kozaki, Tsutomu Honma, Tetsuya Yano, Shigeki Yoshida
  • Patent number: 7575839
    Abstract: The object is to provide a magnetic toner with which toner scattering, toner spent to carrier, development of scratch streaks by the magnetic brush on the photoreceptor drum can be prevented for a prolonged period and a good image characteristic (in image density and background fogging) can be maintained for a prolonged period, and an image forming method using the magnetic toner. A two-component developer comprising carriers and toner which contains magnetic particle at least in a binder resin thereof, the magnetic particle being of basically polyhedral shaped shape, vertexes and edges of said polyhedral shape being curved surfaces, said shape having peripheral parts taken as straight lines in a projected image thereof, saturation magnetization of said toner in a magnetic field of 79.6 kA/m being 4.0 to 15.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: August 18, 2009
    Assignee: Kyocera Mita Corporation
    Inventors: Yukinori Nakayama, Kousuke Satou, Kouzou Teramoto, Hiroshi Mizuhata
  • Patent number: 7575840
    Abstract: The toner of the present invention is characterized in that the charges rise up rapidly, the charge quantity is not insufficient nor excessive, the photoreceptor contamination is minimized and the toner is endurable under harsh conditions and against the high stress usage. The magnetic particle contained in the toner is of average particle size 0.01 ?m through 0.50 ?m, is of octahedron shape that is a convex polyhedron surrounded by eight triangles as a basis, each of vertexes and edges of the octahedron being in a curved surface shape and having a portion that can be taken as a straight line on the outer periphery of a projected image of said octahedron. The sphericity of the toner is 0.94 through 0.98. Here, the sphericity is defined by C2/C1, where C1 is a circumferential length of an image projected on a plane and C2 is a circumferential length of an assumed circle area as same as that of the projected image. Further, a number content of the toner of particle size 0.6 ?m through 2.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: August 18, 2009
    Assignee: Kyocera Mita Corporation
    Inventors: Kouzou Teramoto, Yukinori Nakayama, Kousuke Satou, Hiroshi Mizuhata
  • Patent number: 7361442
    Abstract: A developing method is provided in which a developer is carried on a developer carrying member, a thin layer of the developer is formed thereon and a latent image on a latent image bearing member is developed with a developer. The developer is composed of magnetic toner particles containing a binder resin and a magnetic powder. The magnetic powder has a saturation magnetization of 67.0 Am2/kg to 75.0 Am2/kg in a magnetic field of 79.6 kA/m (1,000 oersteds) and has a residual magnetization of 4.5 Am2/kg or less. In the surface profile of the conductive resin coat layer of the developer carrying member, the relationship 1.00?S/A?1.65 is satisfied where S is a surface area of regions zoned by an area A of microscopic unevenness regions from which parts exceeding a reference plane by 0.5×r (r: weight average particle diameter (?m) of a toner used) or more have been excluded.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: April 22, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Satoshi Otake, Masayoshi Shimamura, Yusutaka Akashi, Kazunori Saiki, Nene Dojo, Minoru Ito, Michihisa Magome, Eriko Yanase, Tatsuya Nakamura
  • Publication number: 20070238043
    Abstract: A developing method is provided in which a developer is carried on a developer carrying member, a thin layer of the developer is formed thereon and a latent image on a latent image bearing member is developed with a developer. The developer is composed of magnetic toner particles containing a binder resin and a magnetic powder. The magnetic powder has a saturation magnetization of 67.0 Am2/kg to 75.0 Am2/kg in a magnetic field of 79.6 kA/m (1,000 oersteds) and has a residual magnetization of 4.5 Am2/kg or less. In the surface profile of the conductive resin coat layer of the developer carrying member, the relationship 1.00?S/A?1.65 is satisfied where S is a surface area of regions zoned by an area A of microscopic unevenness regions from which parts exceeding a reference plane by 0.5×r (r: weight average particle diameter (?m) of a toner used) or more have been excluded.
    Type: Application
    Filed: April 17, 2007
    Publication date: October 11, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Satoshi Otake, Masayoshi Shimamura, Yusutaka Akashi, Kazunori Saiki, Nene Dojo, Minoru Ito, Michihisa Magome, Eriko Yanase, Tatsuya Nakamura