Patents by Inventor Shigenori Yaguchi

Shigenori Yaguchi 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: 8652735
    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: Grant
    Filed: August 19, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Kimitoshi Yamaguchi, Hitoshi Iwatsuki, Hiroshi Tohmatsu, Hiroyuki Kishida, Toyoaki Tano, Mariko Takii
  • Patent number: 8637218
    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: Grant
    Filed: July 24, 2012
    Date of Patent: January 28, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Hiroyuki Kishida
  • Publication number: 20140023966
    Abstract: A carrier for developing electrostatic latent images includes a core material; and a covering layer formed of a resin comprising an electroconductive particulate material, overlying the core material, wherein the covering layer includes the electroconductive particulate material in an amount of from 58 to 73% by weight and has a resistivity of from 6.6 to 8.6 ?cm, and wherein the carrier has a high-brightness contrast part at an areal ratio less than 1% and 40 to 90% based on total area thereof at an acceleration voltage of 0.8 KV and 2.0 KV, respectively in an FE-SEM reflection electron image of the surface thereof.
    Type: Application
    Filed: July 1, 2013
    Publication date: January 23, 2014
    Inventors: Toyoshi SAWADA, Shigenori Yaguchi, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Toyoaki Tano, Hiroyuki Kishida, Yumiko Yagi
  • Publication number: 20130252169
    Abstract: A carrier for developing electrostatic latent image, including a particulate magnetic core material; and a coated layer covering the surface of the particulate magnetic core material, wherein the coated layer includes a resin including a silicone resin and a methacrylic ester or an acrylic ester resin, and a filler including a substrate; and an electroconductive layer comprising tin dioxide (SnO2), overlying the substrate, and wherein the carrier includes tin (Sn) in an amount not less than 0.5% by atom and has a ratio (Sn/Si) of tin (Sn) to silicon (Si) of from 0.03 to 0.2 when subjected to an XPS analysis.
    Type: Application
    Filed: March 8, 2013
    Publication date: September 26, 2013
    Inventors: Shigenori Yaguchi, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Hiroyuki Kishida, Toyoaki Tano
  • Patent number: 8524436
    Abstract: In the image forming method, a color toner image and a transparent toner image are formed using a first developing device containing a first developer including color toner and carrier, and a second developing device containing a second developer including transparent toner and carrier. At least the second developing device includes a developer bearing member bearing the second developer for developing an electrostatic image; a developer supplying passage supplying the developer to the developer bearing member while feeding the developer in a first direction; and a developer feeding passage separated from the developer supplying passage at a central portion thereof and feeding the developer used for development in a direction parallel to the first direction. The transparent toner includes a resin and a lubricant and has viscoelastic property such that loss tangent has a peak with height of not less than 3 at a temperature of from 80° C. to 160° C.
    Type: Grant
    Filed: June 24, 2011
    Date of Patent: September 3, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Masashi Nagayama, Mitsuo Aoki, Hideyuki Santo, Shigenori Yaguchi
  • Patent number: 8512928
    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.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: August 20, 2013
    Assignee: Rocoh Company, Ltd.
    Inventors: Hiroyuki Kishida, Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Koichi Sakata, Hitoshi Iwatsuki, Toyoaki Tano, Mariko Takii
  • Publication number: 20130101930
    Abstract: A carrier for developing an electrostatic latent image, including a particulate core material having a magnetism having developed spontaneous magnetization; and a covering layer comprising an electroconductive material, covering the surface of the particulate core material, wherein the carrier has an electrical resistivity Log R [?cm] of from 8.0 to 12.
    Type: Application
    Filed: October 10, 2012
    Publication date: April 25, 2013
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Toyoshi Sawada, Hiroshi Tohmatsu, Hitoshi Iwatsuki, Toyoaki Tano
  • 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: 20130065171
    Abstract: A latent electrostatic image developing carrier including: core particles each having magnetism; and a coating layer covering each of the core particles, wherein the latent electrostatic image developing carrier has a shape factor SF-2 of 115 to 150 and has a bulk density of 1.8 g/cm3 to 2.4 g/cm3, wherein the core particles have a shape factor SF-2 of 120 to 160 and have an arithmetic mean surface roughness Ra of 0.5 ?m to 1.0 ?m, and wherein the coating layer contains a resin and a filler and an amount of the filler contained in the coating layer is 50 parts by mass to 500 parts by mass per 100 parts by mass of the resin contained in the coating layer.
    Type: Application
    Filed: August 23, 2012
    Publication date: March 14, 2013
    Inventors: Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hitoshi Iwatsuki, Toyoaki Tano, Hiroshi Tohmatsu
  • 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: 20120237868
    Abstract: A toner including a binder resin, a colorant, and a release agent is provided. The toner has a peak loss tangent (tan ?) value of 3 or more within a temperature range of 80 to 160° C. Here, the loss tangent (tan ?) is a ratio (G?/G?) of a loss elastic modulus (G?) to a storage elastic modulus (G?). The toner provides a good combination of low-temperature fixability, hot offset resistance, storage stability, coloring power and/or opacifying power, and gloss.
    Type: Application
    Filed: February 24, 2012
    Publication date: September 20, 2012
    Inventors: Saori Yamada, Mitsuo Aoki, Hisashi Nakajima, Masashi Nagayama, Shigenori Yaguchi
  • 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
  • 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: 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: 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: 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
  • Publication number: 20120009514
    Abstract: In the image forming method, at least one color toner image and a transparent toner image are formed using a color developer including a color toner and a carrier and contained in a first developing device, and a second developer including a transparent toner and a carrier and contained in a second developing device. A supplementary developer is supplied at least to the second developing device while discharging excess of the developer in the developing device. The transparent toner includes a lubricant and has a viscoelastic property such that a loss tangent (tan ?), which is defined as a ratio (G?/G?) of loss modulus (G?) to storage modulus (G?), has a peak at a temperature of from 80° C. to 160° C. and the peak has a height of not less than 3.
    Type: Application
    Filed: June 6, 2011
    Publication date: January 12, 2012
    Inventors: Masashi Nagayama, Mitsuo Aoki, Hideyuki Santo, Shigenori Yaguchi
  • Publication number: 20120009518
    Abstract: In the image forming method, a color toner image and a transparent toner image are formed using a first developing device containing a first developer including color toner and carrier, and a second developing device containing a second developer including transparent toner and carrier. At least the second developing device includes a developer bearing member bearing the second developer for developing an electrostatic image; a developer supplying passage supplying the developer to the developer bearing member while feeding the developer in a first direction; and a developer feeding passage separated from the developer supplying passage at a central portion thereof and feeding the developer used for development in a direction parallel to the first direction. The transparent toner includes a resin and a lubricant and has viscoelastic property such that loss tangent has a peak with height of not less than 3 at a temperature of from 80° C. to 160° C.
    Type: Application
    Filed: June 24, 2011
    Publication date: January 12, 2012
    Inventors: Masashi NAGAYAMA, Mitsuo Aoki, Hideyuki Santo, Shigenori Yaguchi
  • Publication number: 20110081608
    Abstract: A transparent toner for electrophotographic image forming method forming an image on a recording medium with one or more chromatic toner and a transparent toner, including a thermoplastic resin; and a lubricant, wherein the transparent toner has a tangent loss (tan ?) determined by the following formula has a maximum peak value not less than 3 in a range of from 80 to 160° C.: tangent loss (tan ?)=loss elastic modulus (G?) of the transparent toner/storage modulus (G?) thereof.
    Type: Application
    Filed: September 29, 2010
    Publication date: April 7, 2011
    Inventors: Shigenori Yaguchi, Shinya Nakayama, Hideyuki Santo, Takahiro Honda