Patents by Inventor Kentaro Yamawaki

Kentaro Yamawaki 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).

  • Publication number: 20200150553
    Abstract: A charging member 2 that charges an image bearing member 1 has an electrically conductive support and an elastic layer in contact with the image bearing member 1. The elastic layer includes a semi-conductive rubber composition having a matrix-domain structure including a matrix and domains having electric conductivity. The matrix has a higher volume resistivity than the domain. The developer includes a toner having toner particles. The toner particles each have a surface layer including an organosilicon polymer. The organosilicon polymer has a structure represented by R—SiO3/2 (R is a hydrocarbon group having at least 1 and not more than 6 carbon atoms). The adhesion ratio of the organosilicon polymer on the surface of the toner particle is 90% or more.
    Type: Application
    Filed: November 11, 2019
    Publication date: May 14, 2020
    Inventors: Shinichi Agata, Shinichi Hagiwara, Yoshihiro Mitsui, Kosuke Ikada, Kentaro Yamawaki
  • Publication number: 20200142329
    Abstract: A toner having a toner particle including a binder resin and a wax, wherein the wax includes a specific diester compound; a proportion As of an area occupied by the wax in a region from a surface of the toner particle to 0.5 ?m is 15.0% or less; wax domains are observed in the cross section of the toner particle, and an average number of the domains per cross section of one toner particle is from 10 to 2000; when a mass concentration of a polyvalent metal element in the toner particle determined by fluorescent X-ray analysis is denoted by Mi (ppm), Mi is from 3.5 ppm to 1100 ppm; and when a mass concentration of a polyvalent metal element in the toner particle determined by X-ray photoelectron spectroscopy is denoted by Ms (ppm), Mi>Ms.
    Type: Application
    Filed: October 31, 2019
    Publication date: May 7, 2020
    Inventors: Kentaro Yamawaki, Satoshi Otsuji, Masamichi Sato, Hidekazu Fumita
  • Publication number: 20200124998
    Abstract: A toner comprising a toner particle that contains a binder resin and a wax; in a microcompression test under a maximum load condition of 1.1×10?3 N, a force applied to the toner particle when a percentage deformation of the toner particle with reference to a number-average particle diameter of the toner particle at 25° C. reaches 15% is 0.10 to 1.00 mN and the force applied to the toner particle when the percentage deformation at 45° C. reaches 15% is 0.10 to 0.40 mN; and when the force applied to the toner particle is a variable and the percentage deformation of the toner particle is from 15 to 30%, the rate of increase in the percentage deformation of the toner particle at 25° C. and the rate of increase in the percentage deformation of the toner particle at 45° C. satisfy specific formula.
    Type: Application
    Filed: October 14, 2019
    Publication date: April 23, 2020
    Inventors: Shohei Kototani, Kentaro Yamawaki, Koji Abe, Tomonori Matsunaga, Masamichi Sato
  • Patent number: 10545422
    Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.
    Type: Grant
    Filed: April 8, 2019
    Date of Patent: January 28, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
  • Patent number: 10503090
    Abstract: Provided is a toner containing a colorant and a binder resin, wherein, in a wettability test of the toner with respect to a methanol/water mixed solvent, the methanol concentration when the transmittance of light at a wavelength of 780 nm is 50% is at least 5.0 volume % and not more than 30.0 volume %, and the interparticle force measured by rupturing a consolidation of the toner formed by compression of the toner with a load of 78.5 N is at least 1.0 nN and not more than 25.0 nN.
    Type: Grant
    Filed: May 2, 2018
    Date of Patent: December 10, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsuneyoshi Tominaga, Akane Masumoto, Toshihiko Katakura, Shiro Kuroki, Kenta Kamikura, Sara Yoshida, Shinsuke Mochizuki, Tsutomu Shimano, Kentaro Yamawaki, Tomonori Matsunaga, Kunihiko Nakamura
  • Publication number: 20190369529
    Abstract: Provided is an image forming apparatus capable of forming a high quality electrophotographic image. The image forming apparatus includes toner in which an organosilicon polymer is stuck to a toner base at a predetermined sticking ratio, an electrophotographic photoreceptor having a surface layer having a predetermined hardness and a predetermined elastic deformation ratio, and an intermediate transfer body having a surface having a predetermined hardness, and also includes a unit that provides a circumferential velocity difference between the electrophotographic photoreceptor and the intermediate transfer body.
    Type: Application
    Filed: May 28, 2019
    Publication date: December 5, 2019
    Inventors: Yasutaka Yagi, Satoshi Otsuji, Hidekazu Fumita, Masatake Tanaka, Kentaro Yamawaki, Atsushi Okuda, Tsutomu Nishida
  • Publication number: 20190369512
    Abstract: Provided is a process cartridge including: an electrophotographic photoreceptor; a charging unit configured to charge the electrophotographic photoreceptor through abutment against the electrophotographic photoreceptor; a developing unit configured to develop an electrostatic latent image formed on the electrophotographic photoreceptor with a toner to form a toner image; and a cleaning unit configured to remove the toner on the electrophotographic photoreceptor by bringing a blade into abutment against the electrophotographic photoreceptor, wherein the toner includes a toner base containing a coloring agent and a binder resin, and has a surface layer containing an organosilicon polymer having a specific sticking ratio to a toner base, and wherein the electrophotographic photoreceptor includes a supporting member and a surface layer, and the surface layer has a specific universal hardness value and a specific elastic deformation ratio (We).
    Type: Application
    Filed: May 28, 2019
    Publication date: December 5, 2019
    Inventors: Atsushi Okuda, Tsutomu Nishida, Yuka Ishiduka, Nobuhiro Nakamura, Hiroyuki Watanabe, Hideharu Shimozawa, Satoshi Otsuji, Kentaro Yamawaki, Daisuke Miura
  • Patent number: 10429757
    Abstract: A toner comprising a toner particle that contains a binder resin and a release agent, wherein the toner particle has a surface layer that contains an organosilicon polymer and the luminance histogram of a backscattered electron image of the toner particle has two peak values P1 and P2 and a minimum value V between P1 and P2, P2 originates from the organosilicon polymer, and the luminance giving P1 and P2 are in specific ranges, percentages for P1 and P2 are each at least 0.50%, and using the luminance Bl at V as a reference point, specific relationships are satisfied by A1, AV, and A2, where A1 is the total number of pixels at luminance from 0 to (Bl?30 ), AV is the total number of pixels at luminance from (Bl?29 ) to (Bl+29 ), and A2 is the total number of pixels at luminance from (Bl+30 ) to 255.
    Type: Grant
    Filed: May 8, 2018
    Date of Patent: October 1, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Toshihiko Katakura, Shiro Kuroki
  • Publication number: 20190235406
    Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.
    Type: Application
    Filed: April 8, 2019
    Publication date: August 1, 2019
    Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
  • Patent number: 10303074
    Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.
    Type: Grant
    Filed: May 9, 2018
    Date of Patent: May 28, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
  • Publication number: 20180329327
    Abstract: A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.0×10?4 N, of from 200 MPa to 1,100 MPa.
    Type: Application
    Filed: May 9, 2018
    Publication date: November 15, 2018
    Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
  • Publication number: 20180329320
    Abstract: A toner comprising a toner particle that contains a binder resin and a release agent, wherein the toner particle has a surface layer that contains an organosilicon polymer and the luminance histogram of a backscattered electron image of the toner particle has two peak values P1 and P2 and a minimum value V between P1 and P2, P2 originates from the organosilicon polymer, and the luminance giving P1 and P2 are in specific ranges, percentages for P1 and P2 are each at least 0.50%, and using the luminance Bl at V as a reference point, specific relationships are satisfied by A1, AV, and A2, where A1 is the total number of pixels at luminance from 0 to (Bl?30), AV is the total number of pixels at luminance from (Bl?29) to (Bl+29), and A2 is the total number of pixels at luminance from (Bl+30) to 255.
    Type: Application
    Filed: May 8, 2018
    Publication date: November 15, 2018
    Inventors: SARA YOSHIDA, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Toshihiko Katakura, Shiro Kuroki
  • Publication number: 20180329332
    Abstract: Provided is a toner containing a colorant and a binder resin, wherein, in a wettability test of the toner with respect to a methanol/water mixed solvent, the methanol concentration when the transmittance of light at a wavelength of 780 nm is 50% is at least 5.0 volume % and not more than 30.0 volume %, and the interparticle force measured by rupturing a consolidation of the toner formed by compression of the toner with a load of 78.5 N is at least 1.0 nN and not more than 25.0 nN.
    Type: Application
    Filed: May 2, 2018
    Publication date: November 15, 2018
    Inventors: Tsuneyoshi Tominaga, Akane Masumoto, Toshihiko Katakura, Shiro Kuroki, Kenta Kamikura, Sara Yoshida, Shinsuke Mochizuki, Tsutomu Shimano, Kentaro Yamawaki, Tomonori Matsunaga, Kunihiko Nakamura
  • Patent number: 9864290
    Abstract: Disclosed is a toner including toner particles each including a core portion that contains a binder resin, and a surface layer containing an organosilicon polymer, in which each of the toner particles contains a polyvalent metal element having a resistivity of 2.5×10?8 ?·m or more and 10.0×10?8 ?·m or less at 20° C., and when the toner particles are subjected to X-ray fluorescence analysis, a net intensity originating from the polyvalent metal element is 0.10 kcps or more and 30.00 kcps or less.
    Type: Grant
    Filed: May 8, 2017
    Date of Patent: January 9, 2018
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kentaro Yamawaki, Shiro Kuroki, Toshihiko Katakura, Akane Masumoto, Tsuneyoshi Tominaga
  • Publication number: 20170329246
    Abstract: Disclosed is a toner including toner particles each including a core portion that contains a binder resin, and a surface layer containing an organosilicon polymer, in which each of the toner particles contains a polyvalent metal element having a resistivity of 2.5×10?8 ?·m or more and 10.0×10?8 ?·m or less at 20° C., and when the toner particles are subjected to X-ray fluorescence analysis, a net intensity originating from the polyvalent metal element is 0.10 kcps or more and 30.00 kcps or less.
    Type: Application
    Filed: May 8, 2017
    Publication date: November 16, 2017
    Inventors: Kentaro Yamawaki, Shiro Kuroki, Toshihiko Katakura, Akane Masumoto, Tsuneyoshi Tominaga
  • Patent number: 9366981
    Abstract: A toner which includes a binder resin, a colorant and a hydrocarbon wax has a ratio W1/W2 of the half width W1 (° C.) of a endothermic peak derived from melting of the hydrocarbon wax in a first temperature rise process on the toner to the half width W2 (° C.) of a endothermic peak derived from melting of the hydrocarbon wax in a second temperature rise process, as measured with a differential scanning calorimeter, with the ratio W1/W2 being not less than 0.50 and not more than 0.90.
    Type: Grant
    Filed: June 24, 2014
    Date of Patent: June 14, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kentaro Yamawaki, Takeshi Tsujino, Hidekazu Fumita, Nobuhisa Abe, Junya Asaoka
  • Patent number: 9341967
    Abstract: A method for producing toner particles by a suspension polymerization method or a dissolution suspension method comprising: applying an inorganic dispersion stabilizer-containing liquid (liquid A) to a part that can come into contact with a polymerizable monomer composition or toner particle composition, the part being on an inner wall of a vessel used in a polymerization step or a vessel used in a solvent removal step; after the application of the liquid A, carrying out the polymerization step or solvent removal step; discharging the contents of the vessel after the completion of this polymerization step or solvent removal step; and after the contents of the vessel have been discharged, bringing an acidic aqueous solution (liquid B) to dissolve the inorganic dispersion stabilizer into contact with the inner wall of the vessel.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: May 17, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takeshi Tsujino, Kentaro Yamawaki, Junya Asaoka, Motoya Fukushima
  • Publication number: 20150185645
    Abstract: A method for producing toner particles by a suspension polymerization method or a dissolution suspension method comprising: applying an inorganic dispersion stabilizer-containing liquid (liquid A) to a part that can come into contact with a polymerizable monomer composition or toner particle composition, the part being on an inner wall of a vessel used in a polymerization step or a vessel used in a solvent removal step; after the application of the liquid A, carrying out the polymerization step or solvent removal step; discharging the contents of the vessel after the completion of this polymerization step or solvent removal step; and after the contents of the vessel have been discharged, bringing an acidic aqueous solution (liquid B) to dissolve the inorganic dispersion stabilizer into contact with the inner wall of the vessel.
    Type: Application
    Filed: December 24, 2014
    Publication date: July 2, 2015
    Inventors: Takeshi Tsujino, Kentaro Yamawaki, Junya Asaoka, Motoya Fukushima
  • Publication number: 20150004535
    Abstract: A toner which includes a binder resin, a colorant and a hydrocarbon wax has a ratio W1/W2 of the half width W1 (° C.) of a endothermic peak derived from melting of the hydrocarbon wax in a first temperature rise process on the toner to the half width W2 (° C.) of a endothermic peak derived from melting of the hydrocarbon wax in a second temperature rise process, as measured with a differential scanning calorimeter, with the ratio W1/W2 being not less than 0.50 and not more than 0.90.
    Type: Application
    Filed: June 24, 2014
    Publication date: January 1, 2015
    Inventors: Kentaro Yamawaki, Takeshi Tsujino, Hidekazu Fumita, Nobuhisa Abe, Junya Asaoka
  • Patent number: 7411267
    Abstract: The invention provides a semiconductor integrated circuit device with improved designing efficiency while achieving higher functions. An inner circuit is surrounded by a plurality of cells in which a first switch element for connecting a power supply voltage line or a ground voltage supply line to a power supply line of an internal circuit is disposed below power supply lines extending in a first and second directions, and the power lines are connected together.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: August 12, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Kentaro Yamawaki, Yoshihiko Yasu, Yasuto Igarashi, Takashi Kuraishi, Kazumasa Yanagisawa