Patents by Inventor Koichi Sakata

Koichi Sakata 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: 8431312
    Abstract: The present invention provides a carrier which includes core material particles, and a coating layer on surfaces of the core material particles, wherein the coating layer contains a crosslinked product which is obtained by condensation of a silicone resin with an organic zirconium catalyst, the silicone resin having at least one of a silanol group and a functional group capable of generating a silanol group by means of hydrolysis.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: April 30, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki
  • Publication number: 20130065175
    Abstract: A carrier for developing electrostatic latent image, including a core material; and a coated layer covering the core material, including a binder resin and a particulate material, wherein the core material is exposed on the surface of the carrier at an areal ratio of from 0.1 to 5.0% and has the largest exposed part having an areal ratio not greater than 0.03%, and wherein the coated layer comprises the particulate material in an amount of from 100 to 500 parts by weight per 100 parts by weight of the binder resin.
    Type: Application
    Filed: July 24, 2012
    Publication date: March 14, 2013
    Inventors: Koichi Sakata, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Hiroyuki Kishida
  • Publication number: 20130016999
    Abstract: To provide an image forming method, containing: a charging step, a latent electrostatic image forming step, a developing step, a transferring step, and a fixing step, wherein the developing step is developing the latent electrostatic image formed on the latent electrostatic image bearing member with a two-component developer containing a toner and a carrier by a developing element to form a visible image, where the developing contains: stirring the toner and the carrier to prepare the two-component developer to have a flow energy amount of 30 mJ to 70 mJ; and periodically discharging and transporting the stirred two-component to the developer unit by air pressure to thereby supply the two-component developer for the developing.
    Type: Application
    Filed: July 13, 2012
    Publication date: January 17, 2013
    Inventors: Hiroshi Tohmatsu, Shigenori Yaguchi, Hitoshi Iwatsuki, Toyoaki Tano, Koichi Sakata, Mariko Takii
  • Publication number: 20130004209
    Abstract: A developing device including a developer container and a developer bearing member is provided. The developer container contains a two-component developer comprising toner particles and magnetic carrier particles having a ten-point average surface roughness Rz of 0.5 to 3.0 ?m. The developer bearing member is a cylindrical member containing a magnetic field generator having multiple magnetic poles. The developer bearing member is adapted to bear the two-component developer on a surface thereof and to convey the two-component developer as the surface rotates. The developer bearing member has a ten-point average surface roughness Rz of 10 to 30 ?m. The multiple magnetic poles include three developer bearing poles each adapted to generate a magnetic field having a strength enough for retaining the two-component developer on a surface of the developer bearing member. The three developer bearing poles consist of a developing pole, a pre-developing pole, and a post-developing pole.
    Type: Application
    Filed: June 18, 2012
    Publication date: January 3, 2013
    Inventors: Hiroyuki KISHIDA, Shigenori Yaguchi, Toyoshi Sawada, Toyoaki Tano, Koichi Sakata
  • Publication number: 20120320649
    Abstract: A discharge controller carries out discharge control by determining a voltage to be applied to a conduction control terminal of each of switching elements such that a current in a non-saturation region of one of the switching elements is lower than a current in a non-saturation region of the other thereof, and applying the voltage to the conduction control terminal of each switching element with an opening-closing member opening an electrical path to turn on the switching elements, resulting in short-circuit of both electrodes of a capacitor so that a discharge current is outputted from the capacitor based on the discharge control. A manipulator manipulates, based on a value of the discharge current, how to apply the voltage to the conduction control terminal of the one of the switching elements, thus controlling an amount of heat to be generated in the one of the switching elements.
    Type: Application
    Filed: March 30, 2011
    Publication date: December 20, 2012
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Yoshiyuki Hamanaka, Tsuneo Maebara, Yusuke Shindo, Koichi Sakata
  • Publication number: 20120235488
    Abstract: A power converter includes a backup power source Eb provided separately from a power source Es and designed to supply power during a discharge period, and a discharging driver Mb that turns on/off an upper-arm (one) switching element in series-connected switching elements Qu and Qd based on a drive signal that has at least one of a voltage and a frequency, and drives a lower-arm (the other) switching element Qd such that it is always on, the at least one of the voltage and the frequency of the drive signal being within a predetermined range lower than a drive signal outputted from a normal driver Mu, Md.
    Type: Application
    Filed: May 12, 2011
    Publication date: September 20, 2012
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Yoshiyuki Hamanaka, Tsuneo Maebara, Koichi Sakata
  • Publication number: 20120236617
    Abstract: A motor control apparatus 1 includes an inverter 10, a smoothing capacitor 11, power-converting drivers 120 to 125, a power-converting power supply circuit 13, and discharging drivers 140 and 141. The inverter 10 includes switching circuits 100 to 102 comprised of series-connected two IGBTs. The power-converting drivers 120 to 125 apply an output voltage of the power-converting power supply circuit 13 to the switching circuits 120 to 125 to drive them, thus performing power conversion. The discharging drivers 140 and 141 simultaneously turn on IGBTs 100a and 100b of the switching circuit 100 to discharge the smoothing capacitor 11 when the output voltage of the power-converting power supply circuit 13 is equal to or lower than a threshold. This prevents discharging of the smoothing capacitor during power converting operations.
    Type: Application
    Filed: May 11, 2011
    Publication date: September 20, 2012
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Yoshiyuki Hamanaka, Koichi Sakata
  • Publication number: 20120230725
    Abstract: A developing device including a developer bearing member containing a magnetic field generator having multiple magnetic poles and a developer containing chamber is provided. The developer containing chamber contains a two-component developer comprising magnetic carrier particles having a saturated magnetization of 58 to 70 emu/g in a magnetic field of 1 KOe and toner particles, and has a divider to define an upper supply chamber and a lower collection chamber. The supply chamber includes a supply conveyer to supply the two-component developer to the developer bearing member at an upstream side from the developing area. The collection chamber includes a collection conveyer to collect the two-component developer from the developer bearing member at a downstream side from the developing area. The multiple magnetic poles includes three developer bearing poles capable of bearing the developer on its surface.
    Type: Application
    Filed: March 5, 2012
    Publication date: September 13, 2012
    Inventors: Koichi SAKATA, Shigenori Yaguchi, Toyoshi Sawada, Hitoshi Iwatsuki, Hiroyuki Kishida
  • Patent number: 8257896
    Abstract: A carrier which is capable of avoiding excess blocking of the carrier particles at the time of forming a covering layer and is excellent in durability, a developer containing the carrier, and a developer container containing the developer, as well as an image forming method and a process cartridge which use the developer are provided. A carrier including at least a core material particle and a covering layer, a surface of the core material particle being covered with the covering layer, wherein the covering layer contains a condensate which is obtained by condensation of a silicone resin having at least one of a silanol group and a functional group which can be converted to the silanol group by hydrolysis, using a titanium diisopropoxy bis(ethylaceto-acetate) catalyst.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: September 4, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Minoru Masuda, Kimitoshi Yamaguchi, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
  • Publication number: 20120212160
    Abstract: In an electric power conversion system having a discharge control device capable of discharging a voltage charged in a capacitor to a voltage of not more than a predetermined voltage, a linear regulator decreases a voltage of the capacitor and outputs the decreased voltage to a drive unit at a bottom arm in a U phase. A flyback converter for discharging use inputs an output of the linear regulator, and outputs electric power to a drive unit at an upper arm in the U phase. When detecting that own vehicle collides with an obstacle, the discharge control device starts to execute discharge control of the capacitor by turning off a photo coupler and turning on the linear regulator.
    Type: Application
    Filed: May 11, 2011
    Publication date: August 23, 2012
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Yusuke Shindo, Tsuneo Maebara, Koichi Sakata
  • 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: 8211610
    Abstract: The carrier includes a particulate core material having magnetism; and a resin layer located on the surface of the particulate core material. The resin layer is prepared by forming a layer including a copolymer, which includes a unit (A) having a specific acrylic siloxane structure, a unit (B) having a specific acrylic silicone structure having a crosslinking ability, and a unit (C) having a specific acrylic structure in a specific ratio, on the particulate core material, and then subjecting the layer to a heat treatment to crosslink the layer.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: July 3, 2012
    Assignee: Ricoh Company Limited
    Inventors: Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano
  • Patent number: 8145101
    Abstract: A developing device capable of conveying discharged developer to the outside of the device well by preventing developer from firmly adhering within a discharge conveyance path, as well as an image forming apparatus and a process cartridge having this developing device.
    Type: Grant
    Filed: June 9, 2008
    Date of Patent: March 27, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Junichi Terai, Koichi Kato, Koichi Sakata, Maiko Koeda, Kentaroh Tomita, Kiyonori Tsuda
  • Patent number: 8142900
    Abstract: A laser-weldable polybutylene terephthalate-series resin composition having a high laser weldability, a high welding strength, and a high heat shock resistance is provided. The laser-weldable PBT-series resin composition comprises (A) a polybutylene terephthalate-series resin and (B) a core-shell polymer (e.g., a core-shell polymer having an acrylic rubber as a core thereof), and if necessary (C) a filler or reinforcing agent (e.g., a glass fiber) and a polycarbonate-series resin. In the resin composition, the core-shell polymer (B) may usually have an average particle size of not less than 2 ?m.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: March 27, 2012
    Assignee: Wintech Polymer Ltd.
    Inventor: Koichi Sakata
  • Publication number: 20120064451
    Abstract: A carrier comprising a magnetic core particle having a shape factor SF-2 of 130 to 160 and a resin layer covering a surface of the magnetic core particle. The resin layer comprises a conductive particle and a resin obtained by heating a copolymer comprising a silicon-containing A unit and another silicon-containing B unit having.
    Type: Application
    Filed: September 6, 2011
    Publication date: March 15, 2012
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii
  • Publication number: 20120057898
    Abstract: A carrier including a magnetic core particle and a resin layer covering a surface of the magnetic core particle. The magnetic core particle is a ferrite particle including strontium in an amount of 0.005 to 3% by mass, measured by fluorescent X-ray spectroscopy. The resin layer comprises a resin obtained by heating a copolymer comprising a silicon-containing unit A and another silicon-containing specific unit B.
    Type: Application
    Filed: August 19, 2011
    Publication date: March 8, 2012
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Kimitoshi Yamaguchi, Hitoshi Iwatsuki, Hiroshi Tohmatsu, Hiroyuki Kishida, Toyoaki Tano, Mariko Takii
  • Publication number: 20120058423
    Abstract: A contact developing method including supplying a two-component developer to an electrostatic latent image on a rotating image bearing member by rotating a developing sleeve and a rotatable magnet having multiple magnetic poles provided inside the developing sleeve, to develop the electrostatic latent image into a toner image. The developing sleeve and the image bearing member rotate in the same direction while facing each other. The two-component developer comprises a non-magnetic toner and a carrier. The carrier comprises a magnetic core particle and a resin layer covering the magnetic core particle. The resin layer comprises a conductive particle and a resin. The conductive particle comprises an alumina-based material and a conductive layer covering the alumina-based material. The resin is obtained by heating a copolymer comprising a monomer A unit and a monomer B unit.
    Type: Application
    Filed: July 13, 2011
    Publication date: March 8, 2012
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Mariko Takii, Toyoshi Sawada, Toyoaki Tano, Hiroshi Tohmatsu, Koichi Sakata, Hiroyuki Kishida, Saori Yamada
  • Publication number: 20120028183
    Abstract: The developing method includes developing an electrostatic latent image on an image bearing member with a two-component developer including a toner and a carrier and born on at least one developer bearing member, whose surface moves at a linear speed of from 300 mm/sec to 2,000 mm/sec. The carrier includes a particulate core material; and a cover layer located on a surface of the core material and including a crosslinked material obtained by crosslinking a resin including a first unit having a specific tris(trialkylsiloxy) silyl group and a second unit having a specific alkoxysilyl group having a crosslinking ability. Each of the first unit and the second unit is included in the resin in a molar ratio of from 0.1 to 0.9 based on all the units included in the resin.
    Type: Application
    Filed: July 19, 2011
    Publication date: February 2, 2012
    Inventors: Hisashi NAKAJIMA, Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii, Minoru Masuda, Koichi Sakata, Saori Yamada, Hiroyuki Kishida
  • Patent number: 8104176
    Abstract: A method of manufacturing a developing agent regulating member is provided. The method includes providing a non-magnetic member and a magnetic member. The non-magnetic member and the magnetic member are fixed together by caulking such that an end face of the non-magnetic member and an end face of the magnetic member are substantially aligned with each other, and such that the non-magnetic member and the magnetic member are closely pressed together in order to reduce a gap between the non-magnetic member and the magnetic member. The end face of the non-magnetic member and the end face of the magnetic member are polished so as to prepare the regulating face of the developing agent regulating member by making the end face of the non-magnetic member and the end face of the magnetic member flush.
    Type: Grant
    Filed: September 15, 2008
    Date of Patent: January 31, 2012
    Assignee: Ricoh Company, Ltd.
    Inventors: Yutaka Takahashi, Koichi Sakata
  • Patent number: 8045892
    Abstract: A developing unit used in an image forming apparatus with a latent image carrier includes a developer carrier, a supply compartment, a recovery compartment, a separation member, and a gap. The developer carrier facing the latent image carrier rotates while carrying two-component developer containing toner and carrier and supplies the toner to the latent image. The supply compartment includes a supply transport member to transport the developer in a first direction. The recovery compartment includes a recovery transport member to transport the developer in a second direction. The separation member includes one end portion facing the latent image carrier at a facing area. The separation member separates the supply compartment and the recovery compartment and is disposed above the recovery compartment behind the separation member. The gap is provided at the facing area. The gap has a width of not more than 1.4 millimeters.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: October 25, 2011
    Assignee: Ricoh Company Limited
    Inventors: Koichi Sakata, Satoru Yoshida