Patents by Inventor Toyoshi Sawada

Toyoshi Sawada 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: 8748071
    Abstract: To provide an image forming method including conveying a toner by means of a toner supply device that supplies the toner from inside a toner housing container into a developer housing section of a developing device with the use of a screw pump, and forming an image on a recording medium by developing a latent image on a latent image bearing member to form a toner image with the use of a developer and by transferring the toner image to the recording medium by means of a transfer device, wherein the toner is formed by adding small particle size silica to toner base particles, and wherein when A represents the average degree of circularity of the toner, and B, expressed as percent by mass, represents the amount of the small particle size silica relative to the mass of the toner base particles, the expression ?18A+17.92?B??34A+33.96 is satisfied.
    Type: Grant
    Filed: November 19, 2008
    Date of Patent: June 10, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoshi Kojima, Toyoshi Sawada, Tsuneyasu Nagatomo
  • Patent number: 8741520
    Abstract: The present invention provides an image forming toner including at least a linear polyester resin (b1) as a binder resin, wherein the linear polyester resin (b1) is obtained by reacting a polyester diol (b11) having a polyhydroxycarboxylic acid skeleton, with a polyester diol (b12) other than the polyester diol (b11) in the presence of a chain extending agent.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: June 3, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Toyoshi Sawada, Akihiro Kotsugai, Akiyoshi Sabu
  • Publication number: 20140113226
    Abstract: Toner contains a mother toner particle containing a binder resin and a coloring agent and an external additive to cover the mother toner particle, wherein the external additive contains a resin particle, wherein the resin particle has an outer shell layer formed of silica or modified silica, wherein the resin particle has a non-spherical form with a shape factor (SF) of 1.
    Type: Application
    Filed: October 7, 2013
    Publication date: April 24, 2014
    Inventors: Masayuki ISHII, Toyoshi Sawada
  • Publication number: 20140080051
    Abstract: To provide a toner (X), which contains toner particles, each toner particle contains: a core phase (Q) containing a crystalline resin (A); and a shell phase (S) provided on a surface of the core phase (Q), where the shell phase (S) contains a crystalline polyurethane resin (B), wherein maximum peak temperature (Ta) of heat of melting of the crystalline resin (A) is 40° C. to 70° C., and maximum peak temperature (Tu) of heat of melting of the crystalline polyurethane resin (B) is 50° C. to 90° C.
    Type: Application
    Filed: September 17, 2013
    Publication date: March 20, 2014
    Inventors: Toyoshi SAWADA, Masahide YAMADA, Atsushi YAMAMOTO, Tatsuya MORITA, Satoyuki SEKIGUCHI, Keiji MAKABE, Kousuke NAGATA
  • Patent number: 8663892
    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: Grant
    Filed: August 23, 2012
    Date of Patent: March 4, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigenori Yaguchi, Kimitoshi Yamaguchi, Toyoshi Sawada, Hitoshi Iwatsuki, Toyoaki Tano, Hiroshi Tohmatsu
  • Publication number: 20140051019
    Abstract: Toner contains a binder resin containing a crystalline resin having a urethane and/or urea bonding; and a colorant, wherein in a diffraction spectrum of the toner as measured by an X-ray diffraction instrument, a ratio {C/(C+A)} of an integral intensity C of the spectrum derived from the crystalline structure to an integral intensity A of the spectrum derived from the non-crystalline structure is 0.12 or greater, wherein the toner satisfies the following relation 1: T1?T2?30° C. (Relation 1), where T1 represents the maximum endothermic peak in the first temperature rising from 0° C. to 100° C. at the temperature rising rate of 10° C./min and T2 represents the maximum exothermic peak in the first temperature falling from 100° C. to 0° C. at the temperature falling rate of 10° C./min as T1 and T2 are measured by diffraction scanning calorimetry (DSC).
    Type: Application
    Filed: August 5, 2013
    Publication date: February 20, 2014
    Inventors: Satoyuki Sekiguchi, Hiroshi Yamashita, Minoru Masuda, Susumu Chiba, Tatsuya Morita, Atsushi Yamamoto, Shinya Nakayama, Masahide Yamada, Kohsuke Nagata, Keiji Makabe, Toyoshi Sawada
  • 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: 8652738
    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: Grant
    Filed: July 13, 2011
    Date of Patent: February 18, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Kimitoshi Yamaguchi, Shigenori Yaguchi, Hitoshi Iwatsuki, Mariko Takii, Toyoshi Sawada, Toyoaki Tano, Hiroshi Tohmatsu, Koichi Sakata, Hiroyuki Kishida, Saori Yamada
  • 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
  • Patent number: 8603713
    Abstract: A toner including a colorant, a thermoplastic resin (a) comprising an amorphous polyester resin having a main chain having a polyhydroxycarboxylic acid skeleton, and a thermoplastic resin (b) is provided. The toner is manufactured by a method including mixing the colorant with the thermoplastic resin (a) to prepare a preliminary mixture, and mixing the preliminary mixture with the thermoplastic resin (b).
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: December 10, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Akihiro Kotsugai, Toyoshi Sawada, Ryota Inoue, Akiyoshi Sabu, Shingo Sakashita, Keiko Osaka, Yukiko Nakajima
  • 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: 20130164665
    Abstract: A toner including a mother particle and an external additive covering a surface of the mother particle is provided. The mother particle includes a binder resin, a colorant, and a release agent. The external additive includes a particulate cellulose having a number average particle diameter within a range of 15 to 105 nm.
    Type: Application
    Filed: November 16, 2012
    Publication date: June 27, 2013
    Inventors: Masayuki ISHII, Toyoshi Sawada
  • 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
  • Patent number: 8383307
    Abstract: The toner includes a binder resin; a release agent; a colorant; and a dispersing resin configured to disperse the release agent. The dispersing resin includes a polyhydroxycarboxylic acid unit obtained from an optically active monomer. The polyhydroxycarboxylic acid unit has an optical purity of not greater than 80%, wherein the optical purity is defined as the absolute value of difference between the mole percentage of a L-monomer in the optically active monomer and the mole percentage of a D-monomer in the optically active monomer.
    Type: Grant
    Filed: October 8, 2009
    Date of Patent: February 26, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Ryota Inoue, Akihiro Kotsugai, Toyoshi Sawada, Akiyoshi Sabu
  • Patent number: 8377620
    Abstract: An image forming method including charging an image bearing member by applying combination of DC voltage and AC voltage with frequency of 6.5 to 8.5 cycle/mm; irradiating the image bearing member with light to form an electrostatic image; developing the electrostatic image with a developer including toner to form a toner image; transferring the toner image onto a receiving material; fixing the toner image; cleaning the image bearing member with a blade; then applying a lubricant to the image bearing member; and then spreading the lubricant with a spreading member countering the image bearing member. The toner includes toner particles granulated in an aqueous medium; and at least three kinds of external additives including a first particulate hydrophobic silica, a particulate hydrophobic titanium oxide and a second particulate hydrophobic silica respectively having BET specific surface areas of 20 to 40 m2/g, 40 to 80 m2/g, and 130 to 300 m2/g.
    Type: Grant
    Filed: November 24, 2008
    Date of Patent: February 19, 2013
    Assignee: Ricoh Company, Limited
    Inventors: Tsuneyasu Nagatomo, Toyoshi Sawada, Satoshi Kojima
  • 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: 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