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).
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Publication number: 20200150553Abstract: 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: ApplicationFiled: November 11, 2019Publication date: May 14, 2020Inventors: Shinichi Agata, Shinichi Hagiwara, Yoshihiro Mitsui, Kosuke Ikada, Kentaro Yamawaki
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Publication number: 20200142329Abstract: 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: ApplicationFiled: October 31, 2019Publication date: May 7, 2020Inventors: Kentaro Yamawaki, Satoshi Otsuji, Masamichi Sato, Hidekazu Fumita
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Publication number: 20200124998Abstract: 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: ApplicationFiled: October 14, 2019Publication date: April 23, 2020Inventors: Shohei Kototani, Kentaro Yamawaki, Koji Abe, Tomonori Matsunaga, Masamichi Sato
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Patent number: 10545422Abstract: 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: GrantFiled: April 8, 2019Date of Patent: January 28, 2020Assignee: CANON KABUSHIKI KAISHAInventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
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Patent number: 10503090Abstract: 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: GrantFiled: May 2, 2018Date of Patent: December 10, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Tsuneyoshi Tominaga, Akane Masumoto, Toshihiko Katakura, Shiro Kuroki, Kenta Kamikura, Sara Yoshida, Shinsuke Mochizuki, Tsutomu Shimano, Kentaro Yamawaki, Tomonori Matsunaga, Kunihiko Nakamura
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Publication number: 20190369529Abstract: 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: ApplicationFiled: May 28, 2019Publication date: December 5, 2019Inventors: Yasutaka Yagi, Satoshi Otsuji, Hidekazu Fumita, Masatake Tanaka, Kentaro Yamawaki, Atsushi Okuda, Tsutomu Nishida
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Publication number: 20190369512Abstract: 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: ApplicationFiled: May 28, 2019Publication date: December 5, 2019Inventors: Atsushi Okuda, Tsutomu Nishida, Yuka Ishiduka, Nobuhiro Nakamura, Hiroyuki Watanabe, Hideharu Shimozawa, Satoshi Otsuji, Kentaro Yamawaki, Daisuke Miura
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Patent number: 10429757Abstract: 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: GrantFiled: May 8, 2018Date of Patent: October 1, 2019Assignee: Canon Kabushiki KaishaInventors: Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Toshihiko Katakura, Shiro Kuroki
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Publication number: 20190235406Abstract: 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: ApplicationFiled: April 8, 2019Publication date: August 1, 2019Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
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Patent number: 10303074Abstract: 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: GrantFiled: May 9, 2018Date of Patent: May 28, 2019Assignee: CANON KABUSHIKI KAISHAInventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
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Publication number: 20180329327Abstract: 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: ApplicationFiled: May 9, 2018Publication date: November 15, 2018Inventors: Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Sara Yoshida, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Toshihiko Katakura, Shiro Kuroki
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Publication number: 20180329320Abstract: 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: ApplicationFiled: May 8, 2018Publication date: November 15, 2018Inventors: SARA YOSHIDA, Shinsuke Mochizuki, Tsuneyoshi Tominaga, Kenta Kamikura, Tsutomu Shimano, Kentaro Yamawaki, Akane Masumoto, Tomonori Matsunaga, Kunihiko Nakamura, Toshihiko Katakura, Shiro Kuroki
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Publication number: 20180329332Abstract: 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: ApplicationFiled: May 2, 2018Publication date: November 15, 2018Inventors: Tsuneyoshi Tominaga, Akane Masumoto, Toshihiko Katakura, Shiro Kuroki, Kenta Kamikura, Sara Yoshida, Shinsuke Mochizuki, Tsutomu Shimano, Kentaro Yamawaki, Tomonori Matsunaga, Kunihiko Nakamura
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Patent number: 9864290Abstract: 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: GrantFiled: May 8, 2017Date of Patent: January 9, 2018Assignee: Canon Kabushiki KaishaInventors: Kentaro Yamawaki, Shiro Kuroki, Toshihiko Katakura, Akane Masumoto, Tsuneyoshi Tominaga
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Publication number: 20170329246Abstract: 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: ApplicationFiled: May 8, 2017Publication date: November 16, 2017Inventors: Kentaro Yamawaki, Shiro Kuroki, Toshihiko Katakura, Akane Masumoto, Tsuneyoshi Tominaga
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Patent number: 9366981Abstract: 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: GrantFiled: June 24, 2014Date of Patent: June 14, 2016Assignee: CANON KABUSHIKI KAISHAInventors: Kentaro Yamawaki, Takeshi Tsujino, Hidekazu Fumita, Nobuhisa Abe, Junya Asaoka
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Patent number: 9341967Abstract: 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: GrantFiled: December 24, 2014Date of Patent: May 17, 2016Assignee: CANON KABUSHIKI KAISHAInventors: Takeshi Tsujino, Kentaro Yamawaki, Junya Asaoka, Motoya Fukushima
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Publication number: 20150185645Abstract: 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: ApplicationFiled: December 24, 2014Publication date: July 2, 2015Inventors: Takeshi Tsujino, Kentaro Yamawaki, Junya Asaoka, Motoya Fukushima
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Publication number: 20150004535Abstract: 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: ApplicationFiled: June 24, 2014Publication date: January 1, 2015Inventors: Kentaro Yamawaki, Takeshi Tsujino, Hidekazu Fumita, Nobuhisa Abe, Junya Asaoka
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Patent number: 7411267Abstract: 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: GrantFiled: February 3, 2005Date of Patent: August 12, 2008Assignee: Renesas Technology Corp.Inventors: Kentaro Yamawaki, Yoshihiko Yasu, Yasuto Igarashi, Takashi Kuraishi, Kazumasa Yanagisawa