Patents by Inventor Hiromichi Kobayashi

Hiromichi Kobayashi 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: 7598011
    Abstract: It is contemplated to provide irregular shaped ferrite carrier which has a lower resistance, a high specific surface area, a low specific gravity and a longer operational life, and an electrophotographic developer comprising the ferrite carrier which prevents the toner scattering, has a high image density, and is responsive to high-speed and color imaging. The irregular shaped ferrite carrier is characterized in that the carrier particles are irregular shaped, and 40 percent by number or more of the particles have a rock candy sugar shape and/or an oyster shell shape, and that the shape factor (SF-1=R2/S×?/4×100, wherein R is a maximum length and S is a projected area.) is 140 to 250, and the distribution width (?) is 60 or less.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: October 6, 2009
    Assignee: Powdertech Co., Ltd.
    Inventors: Hiromichi Kobayashi, Toru Iwata, Toshio Honjo
  • Publication number: 20090246526
    Abstract: A method for producing ferrite particles by weighing, mixing, then crushing ferrite raw materials, and granulating the resultant slurry, and then sintering the resultant granulated material using a rotary furnace, wherein the sintering is carried out under a positive pressure reducing atmosphere.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 1, 2009
    Applicant: Powdertech Co., Ltd.
    Inventors: Takao SUGIURA, Takashi HIKICHI, Yoshinori KUSAKA, Satoru TANIGUCHI, Tadashi HARAYAMA, Hiromichi KOBAYASHI
  • Publication number: 20090239173
    Abstract: A resin-filled carrier for an electrophotographic developer obtained by filling resin into voids of a porous ferrite core material, wherein the porous ferrite core material has a pore volume of 0.04 to 0.16 mL/g and a peak pore size of 0.9 to 2.0 ?m, and wherein microparticles are included in the resin to be filled, and an electrophotographic developer using this resin-filled carrier.
    Type: Application
    Filed: March 5, 2009
    Publication date: September 24, 2009
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi KOBAYASHI, Takao SUGIURA
  • Patent number: 7566519
    Abstract: A carrier for an electrophotographic developer which is used as an electrophotographic developer in a mixture with a toner and which secures sufficiently the image density and can maintain high-quality images for a long period, and an electrophotographic developer using the carrier, are provided. A resin-filled ferrite carrier for electrophotographic developer obtained by filling, with a resin, avoid of a porous ferrite core whose void continues from the surface to reach the interior of the core, the carrier comprising a plurality of three-dimensional laminate structures in which resin layers and ferrite layers are alternately present, and an electrophotographic developer including the carrier and a toner, are employed.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: July 28, 2009
    Assignee: Powdertech Co., Ltd.
    Inventors: Hiromichi Kobayashi, Tsuyoshi Itagoshi, Tomoyuki Suwa, Toshio Honjo
  • Publication number: 20090176170
    Abstract: A resin-filled carrier for an electrophotographic developer obtained by filling resin into voids of a porous ferrite core material, wherein the porous ferrite core material has a pore volume of 0.055 to 0.16 mL/g and a peak pore size of 0.20 to 0.7 ?m, and an electrophotographic developer using this resin-filled carrier.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 9, 2009
    Applicant: POWDERTECH CO., LTD.
    Inventors: Takao SUGIURA, Takeshi GONDO, Hiromichi KOBAYASHI
  • Patent number: 7553597
    Abstract: A carrier core material containing at least one metal oxide (MLO) having a melting point of not higher than 1000° C. and at least one metal oxide (MHO) having a melting point of not lower than 1800° C., wherein the metal (MH) for constituting the metal oxide (MHO) has an electrical resistivity of not less than 10?5 ?·cm. Also disclosed is a two-component developing agent comprising a coated carrier, which comprises the carrier core material coated with a resin, and toner particles. Further disclosed is an image forming method comprising developing an electrostatic latent image formed on a photosensitive member with the two-component developing agent using an alternating electric field. The carrier core material and the coated carrier have high magnetization and are free from occurrence of leakage of electric charge over a wide range of electric field from low electric field to high electric field. According to the two-component developing agent, an excellent image can be formed.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: June 30, 2009
    Assignee: Powdertech Co., Ltd.
    Inventors: Hiromichi Kobayashi, Issei Shinmura, Tsuyoshi Itagoshi, Yuji Sato
  • Patent number: 7476483
    Abstract: A carrier for electrophotographic developer comprises a resin carrier core comprising a binder resin and magnetic powder dispersed in the binder resin, and a coating layer comprising a coating resin on a surface of the core, the binder resin being a silicone resin obtained by curing of a polysiloxane compound (A) having an epoxy group and a polysiloxane compound (B) having a group capable of reacting with the epoxy group, due to a ring-opening addition reaction; the binder resin containing a functional group which is an epoxy group and/or a group capable of reacting with an epoxy group; the coating resin containing a functional group capable of reacting with the functional group of the binder resin; the functional group of the coating resin and the function group of the binder resin forming a chemical bond.
    Type: Grant
    Filed: December 7, 2005
    Date of Patent: January 13, 2009
    Assignees: Mitsui Mining and Smelting Co., Ltd., Powdertech Co., Ltd.
    Inventors: Yoichi Kamikoriyama, Kenji Suzuoka, Takashi Nakashima, Kazuya Kinoshita, Yuji Sato, Hiromichi Kobayashi, Takeshi Gondo, Takashi Hikichi
  • Patent number: 7442483
    Abstract: A ferrite carrier for the electrophotographic developer containing 40 to 500 ppm of zirconium; a method for preparing a ferrite carrier for the electrophotographic developer, comprising the steps for weighing, mixing, and pulverizing ferrite raw materials, and for granulating, drying, and firing the obtained slurry; wherein a zirconium raw material is added so that the zirconium content after firing becomes 40 to 500 ppm; and an electrophotographic developer using the ferrite carrier.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: October 28, 2008
    Assignee: Powdertech Co., Ltd.
    Inventors: Hiromichi Kobayashi, Kanao Kayamoto, Tadashi Harayama, Issei Shinmura, Toshio Honjo
  • Publication number: 20080238450
    Abstract: An object of the present invention is to provide a quality inspection method for obtaining a specifying factor which can more reliably indicate powder characteristics of a core material for an electrophotographic ferrite carrier. To achieve the object, a method for inspecting the quality of a core material for an electrophotographic ferrite carrier adopts a method characterized in that the impedance of the core material for the electrophotographic ferrite carrier is measured by using an AC-resistance measurement method to obtain a Nyquist diagram (Cole-Cole plot) in which a real number impedance (Z?) is arranged in an X-axis and an imaginary number impedance (Z?) is arranged in a Y-axis and then the characteristics of the particles of the core material for the electrophotographic ferrite carrier is evaluated by using the Nyquist diagram (Cole-Cole plot).
    Type: Application
    Filed: March 28, 2008
    Publication date: October 2, 2008
    Applicant: POWDERTECH CO., LTD.
    Inventors: Koji Aga, Hiromichi Kobayashi
  • Publication number: 20080241726
    Abstract: Employed are a resin-filled ferrite carrier for an electrophotographic developer filled with a resin in voids of a porous ferrite core material, wherein the resin filled in the voids is a silicone resin which has a softening point of 40° C. or above and is cured at or above such softening point, and the filled amount is 7 to 30 parts by weight based on 100 parts by weight of the core material, a method for producing thereof band an electrophotographic developer using this ferrite carrier.
    Type: Application
    Filed: March 4, 2008
    Publication date: October 2, 2008
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi KOBAYASHI, Takao SUGIURA
  • Publication number: 20080199800
    Abstract: A resin-filled ferrite carrier for an electrophotographic developer filled with a silicone resin in voids of a porous ferrite core material which continuously extend from a surface to a core interior, wherein the resin-filled ferrite carrier has an average particle size of 20 to 50 ?m, and (Si/Fe)×100 as determined from X-ray fluorescence elemental analysis is 2.0 to 7.0, and the particle size and (Si/Fe)×100 are correlated, and wherein in the correlation relationship between [(Si/Fe)×100] and the particle size, a gradient (a) in a correlation equation thereof is ?0.50?a?0.15.
    Type: Application
    Filed: February 19, 2008
    Publication date: August 21, 2008
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi KOBAYASHI, Takao SUGIURA
  • Publication number: 20080171281
    Abstract: Disclosed are a ferrite carrier for electrophotographic developer and an electrophotographic developer using the ferrite carrier, wherein: the ferrite carrier is a composite ferrite composed of Li and Mg; when the composition of the ferrite is calculated as a mixture of a Li ferrite having a stoichiometric composition and a Mg ferrite having a stoichiometric composition, the excessive amount of Fe2O3 is less than 5 mol %, or the total excessive amount of Li2O and MgO is less than 1 mol %; the content of the elements other than Li, Mg, Fe and O is 2% by weight or less; and further, the content of Mn in terms of element is 1000 to 9000 ppm.
    Type: Application
    Filed: January 16, 2008
    Publication date: July 17, 2008
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi Kobayashi, Takao Sugiura, Kanao Kayamoto
  • Publication number: 20080163233
    Abstract: A load distribution rate is calculated among resources utilized in a service based on load information for each resource utilized in the service. If it is determined that loads of the service distributed to the resources are excessively distributed and that the loads are to be consolidated, a resource having the smallest load is detected from among the resources utilized in the service and the load of the detected resource is allocated to another resource to consolidate the service load.
    Type: Application
    Filed: September 25, 2007
    Publication date: July 3, 2008
    Applicant: Fujitsu Limited
    Inventor: Hiromichi Kobayashi
  • Patent number: 7288355
    Abstract: Provided are a carrier for electrophotography developers prepared by generating a slight amount of byproducts such as water, alcohol, etc, which carrier is free from release of a magnetic powder, has excellent mechanical strength and durability, and good environmental stability, and further can restrain occurrence of toner spent condition and has favorable fluidity and excellent capability of imparting charging to a toner, a two-component developer comprising the carrier and a method for forming an image using the developer. The carrier for electrophotography developers comprises a magnetic powder dispersed binder resin, the binder resin material comprises (A) a polysiloxane compound having an epoxy group as a functional group and (B) a polysiloxane compound having a group capable of ring-opening addition reaction with the epoxy group of the polysiloxane compound (A), and the binder resin is a silicone resin prepared by curing with ring-opening addition reaction of the epoxy resin.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: October 30, 2007
    Assignees: Mitsui Mining & Smelting Co., Ltd., Powdertech Co., Ltd.
    Inventors: Yoichi Kamikoriyama, Kenji Suzuoka, Takashi Nakashima, Kazuya Kinoshita, Yuji Sato, Hiromichi Kobayashi, Takeshi Gondo, Takashi Hikichi
  • Publication number: 20070180661
    Abstract: A granulating method for forming a particle with a continuous ink-jet method using a liquid material, in which the liquid material containing a solid component and a binder component is supplied into one or more ink-jet nozzles of a continuous ink-jet device, a droplet is formed by having the supplied liquid material flow out the ink-jet nozzle, the droplet is carried in to drying means for drying the droplet, and the carried droplet is dried so as to obtain a granulated particle(s), the granulated particle(s) and a granulating device.
    Type: Application
    Filed: January 17, 2007
    Publication date: August 9, 2007
    Applicant: POWDERTECH CO., LTD.
    Inventors: Koji Aga, Hiromichi Kobayashi
  • Publication number: 20070048649
    Abstract: A carrier for an electrophotographic developer which is used as an electrophotographic developer in a mixture with a toner and which secures sufficiently the image density and can maintain high-quality images for a long period, and an electrophotographic developer using the carrier, are provided. A resin-filled ferrite carrier for electrophotographic developer obtained by filling, with a resin, avoid of a porous ferrite core whose void continues from the surface to reach the interior of the core, the carrier comprising a plurality of three-dimensional laminate structures in which resin layers and ferrite layers are alternately present, and an electrophotographic developer including the carrier and a toner, are employed.
    Type: Application
    Filed: August 25, 2006
    Publication date: March 1, 2007
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi Kobayashi, Tsuyoshi Itagoshi, Tomoyuki Suwa, Toshio Honjo
  • Patent number: 7183033
    Abstract: A carrier core material for an electrophotographic developing agent, which comprises 100 parts by weight of a ferrite component represented by a formula (A) and 0.1 to 5.0 parts by weight of ZrO2 that is present in the ferrite component without forming a solid solution, and which has a magnetization, at 1000(103/4?·A/m), of 65 to 85 Am2/kg and an electrical resistance, at an applied voltage of 1000 V, of 105 to 109 ?. (MnO)x(MgO)y(Fe2O3)z??(A) wherein x, y and z are each expressed in % by mol and are numbers satisfying the conditions of 40?x?60, 0.1?y?10 and x+y+z=100. Also disclosed is a two-component developing agent comprising a coated carrier, which is obtained by coating the above carrier core material with a resin, and toner particles. Further disclosed is an image forming method comprising developing an electrostatic latent image formed by the use of an alternating electric field, with the two-component developing agent.
    Type: Grant
    Filed: February 6, 2004
    Date of Patent: February 27, 2007
    Assignee: Powdertech Co., Ltd.
    Inventors: Issei Shinmura, Hiromichi Kobayashi, Tsuyoshi Itagoshi, Yuji Sato
  • Publication number: 20060269862
    Abstract: A ferrite core material for a resin-filled type carrier, and a resin-filled type carrier which is used as an electrophotographic developer by mixing a toner, sufficiently secure the image density, have no carrier adhesion and can maintain high-quality images over a long period, and an electrophotographic developer using the carrier, are provided. A ferrite core material for a resin-filled type carrier characterized in a void fraction of 10 to 60%, a resin-filled type carrier filled in the carrier core material with a resin, and an electrophotographic developer composed of the resin-filled type carrier and a toner, are provided.
    Type: Application
    Filed: May 31, 2006
    Publication date: November 30, 2006
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi Kobayashi, Tsuyoshi Itagoshi, Tomoyuki Suwa, Toshio Honjo
  • Publication number: 20060194137
    Abstract: It is contemplated to provide irregular shaped ferrite carrier which has a lower resistance, a high specific surface area, a low specific gravity and a longer operational life, and an electrophotographic developer comprising the ferrite carrier which prevents the toner scattering, has a high image density, and is responsive to high-speed and color imaging. The irregular shaped ferrite carrier is characterized in that the carrier particles are irregular shaped, and 40 percent by number or more of the particles have a rock candy sugar shape and/or an oyster shell shape, and that the shape factor (SF-1=R2/S×?/4×100, wherein R is a maximum length and S is a projected area.) is 140 to 250, and the distribution width (?) is 60 or less.
    Type: Application
    Filed: February 28, 2006
    Publication date: August 31, 2006
    Applicant: POWDERTECH CO., LTD.
    Inventors: Hiromichi Kobayashi, Toru Iwata, Toshio Honjo
  • Patent number: 7086380
    Abstract: An apparatus for controlling an opening degree of a throttle valve of an internal combustion engine using a DC motor, in which a real opening degree of the throttle valve is detected, a target opening degree of the throttle valve is set in accordance with an operation state of the internal combustion engine, an output voltage of a DC power source is boosted, and one voltage of the boosted voltage and the output voltage of the DC power source is selected in accordance with an opening degree difference between the real opening degree and the target opening degree to apply the selected one voltage to the DC motor.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: August 8, 2006
    Assignee: Keihin Corporation
    Inventors: Tamikazu Mukasa, Hiromichi Kobayashi