Patents by Inventor Norifumi Muranaka
Norifumi Muranaka 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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Patent number: 11307509Abstract: An electro-conductive layer of an electrophotographic electro-conductive member has a matrix-domain structure. The matrix contains a first rubber. The domain contains a second rubber and electro-conductive particles. Where ? represents an average of ratios of the cross-sectional area of the electro-conductive particles contained in each of the domains to the cross-sectional area of each of the domains appearing on a cross-section of the electro-conductive layer in a thickness direction, and ? represents a standard deviation of the ratios, ?/? is 0 or more and 0.4 or less, and ? is 20% or more and 40% or less. At least eight of samples with a first cubic shape 9 ?m on a side, which are sampled at arbitrary nine positions on the electro-conductive layer, satisfy the specified condition.Type: GrantFiled: October 15, 2020Date of Patent: April 19, 2022Assignee: CANON KABUSHIKI KAISHAInventors: Tetsuo Hino, Yasuhiro Fushimoto, Norifumi Muranaka, Masafumi Kyogaku, Masaki Yamada, Hiroshi Inoue, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
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Patent number: 10996581Abstract: Provided is such a conductive member that a change in its electrical resistance value caused by its long-term use is reduced to the extent possible. The conductive member has a conductive support and a conductive layer, the conductive layer contains a rubber composition formed of a modified epichlorohydrin rubber, and the modified epichlorohydrin rubber has a unit represented by the following formula (1). In the formula (1), R1, R2, and R3 each independently represent hydrogen or a saturated hydrocarbon group having 1 to 18 carbon atoms.Type: GrantFiled: October 2, 2017Date of Patent: May 4, 2021Assignee: CANON KABUSHIKI KAISHAInventors: Norifumi Muranaka, Satoru Yamada, Kazuhiro Yamauchi, Seiji Tsuru, Yuka Muranaka
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Publication number: 20210048759Abstract: An electro-conductive layer of an electrophotographic electro-conductive member has a matrix-domain structure. The matrix contains a first rubber. The domain contains a second rubber and electro-conductive particles. Where ? represents an average of ratios of the cross-sectional area of the electro-conductive particles contained in each of the domains to the cross-sectional area of each of the domains appearing on a cross-section of the electro-conductive layer in a thickness direction, and ? represents a standard deviation of the ratios, ?/? is 0 or more and 0.4 or less, and ? is 20% or more and 40% or less. At least eight of samples with a first cubic shape 9 ?m on a side, which are sampled at arbitrary nine positions on the electro-conductive layer, satisfy the specified condition.Type: ApplicationFiled: October 15, 2020Publication date: February 18, 2021Inventors: Tetsuo Hino, Yasuhiro Fushimoto, Norifumi Muranaka, Masafumi Kyogaku, Masaki Yamada, Hiroshi Inoue, Takumi Furukawa, Hiroaki Watanabe, Kenya Terada, Yuya Tomomizu, Toshimitsu Nakazawa
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Electroconductive member for electrophotography, process cartridge and electrophotographic apparatus
Patent number: 10018927Abstract: An electroconductive member of the present invention includes an electroconductive support layer and a surface layer formed on the circumference of the electroconductive support layer and having a network structure containing an electroconductive fiber, and the electroconductive fiber has ion conductivity, and has an arithmetic mean value of top 10% fiber diameters of 0.2 ?m or more and 15.0 ?m or less. The surface layer always satisfies specific conditions.Type: GrantFiled: March 23, 2015Date of Patent: July 10, 2018Assignee: CANON KABUSHIKI KAISHAInventors: Satoru Yamada, Kazuhiro Yamauchi, Norifumi Muranaka, Tetsuo Hino, Yuichi Kikuchi -
Patent number: 10012924Abstract: An electrophotographic electro-conductive member comprising an electro-conductive mandrel and an electro-conductive elastic layer on the electro-conductive mandrel, wherein the electro-conductive elastic layer has an elastic coefficient of 1 MPa or more and 100 MPa or less, as well as a matrix containing first rubber and a plurality of electro-conductive domains dispersed in the matrix. Each of the electro-conductive domains contains an electro-conductive particle, and the electro-conductive elastic layer includes regions containing second rubber in the circumferences of the electro-conductive domains. The matrix has an elastic coefficient R1, the regions containing second rubber have an elastic coefficient R2, and the elastic coefficients R1 and R2 satisfy a relationship: R1<R2.Type: GrantFiled: October 4, 2016Date of Patent: July 3, 2018Assignee: Canon Kabushiki KaishaInventors: Takeshi Yoshidome, Saki Tominaga, Yasuhiro Fushimoto, Norifumi Muranaka, Kazuhiro Yamauchi
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Patent number: 9958802Abstract: Provided is an electroconductive member for electrophotography capable of charging an electrically chargeable body stably over a long period of time. The electroconductive member includes an electroconductive support and a surface layer on the electroconductive support. The surface layer has a skeleton that is three-dimensionally continuous and a pore that communicates in a thickness direction, and when any region measuring 150 ?m per side of a surface of the surface layer is photographed and equally divided into 60 parts in a vertical direction and 60 parts in a horizontal direction to form 3,600 squares, the number of squares including through holes is 100 or less. The skeleton is non-electroconductive and includes a plurality of particles connected to each other through a neck, and an average value D1 of circle-equivalent diameters of the particles is 0.1 ?m or more and 20 ?m or less.Type: GrantFiled: March 23, 2016Date of Patent: May 1, 2018Assignee: CANON KABUSHIKI KAISHAInventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Norifumi Muranaka, Tetsuo Hino, Satoru Nishioka
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Publication number: 20180039201Abstract: Provided is such a conductive member that a change in its electrical resistance value caused by its long-term use is reduced to the extent possible. The conductive member has a conductive support and a conductive layer, the conductive layer contains a rubber composition formed of a modified epichlorohydrin rubber, and the modified epichlorohydrin rubber has a unit represented by the following formula (1). In the formula (1), R1, R2, and R3 each independently represent hydrogen or a saturated hydrocarbon group having 1 to 18 carbon atoms.Type: ApplicationFiled: October 2, 2017Publication date: February 8, 2018Inventors: Norifumi Muranaka, Satoru Yamada, Kazuhiro Yamauchi, Seiji Tsuru, Yuka Muranaka
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Publication number: 20180024459Abstract: Provided is an electroconductive member for electrophotography capable of charging an electrically chargeable body stably over a long period of time. The electroconductive member includes an electroconductive support and a surface layer on the electroconductive support. The surface layer has a skeleton that is three-dimensionally continuous and a pore that communicates in a thickness direction, and when any region measuring 150 ?m per side of a surface of the surface layer is photographed and equally divided into 60 parts in a vertical direction and 60 parts in a horizontal direction to form 3,600 squares, the number of squares including through holes is 100 or less. The skeleton is non-electroconductive and includes a plurality of particles connected to each other through a neck, and an average value D1 of circle-equivalent diameters of the particles is 0.1 ?m or more and 20 ?m or less.Type: ApplicationFiled: March 23, 2016Publication date: January 25, 2018Inventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Norifumi Muranaka, Tetsuo Hino, Satoru Nishioka
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Patent number: 9811021Abstract: Provided is such a conductive member that a change in its electrical resistance value caused by its long-term use is reduced to the extent possible. The conductive member has a conductive support and a conductive layer, the conductive layer contains a rubber composition formed of a modified epichlorohydrin rubber, and the modified epichlorohydrin rubber has a unit represented by the following formula (1). In the formula (1), R1, R2, and R3 each independently represent hydrogen or a saturated hydrocarbon group having 1 to 18 carbon atoms.Type: GrantFiled: November 3, 2015Date of Patent: November 7, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Norifumi Muranaka, Satoru Yamada, Kazuhiro Yamauchi, Seiji Tsuru, Yuka Muranaka
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Patent number: 9651888Abstract: The electroconductive member has an electroconductive support and a surface layer formed on the electroconductive support, wherein the surface layer has a porous body having a continuous open pore, and the electroconductive member satisfies the following (1) and (2): (1) in a specific condition, a surface potential of the electroconductive member, after an elapse of 10 seconds since a completion of a discharge is 10 V or more; and (2) when applying a direct voltage between a polyethylene terephthalate film as a member to be charged and the electroconductive member, and charging the polyethylene terephthalate film, |Vd|?|Vin|?|Vth| is satisfied within a range of |Vin|>|Vth|, wherein, Vd represents a charge potential of the polyethylene terephthalate film, Vin represents a voltage applied between the electroconductive member and the polyethylene terephthalate film, Vth represents a discharge starting voltage.Type: GrantFiled: September 19, 2014Date of Patent: May 16, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Norifumi Muranaka, Kazuhiro Yamauchi, Yuichi Kikuchi, Koji Otsuka, Masaki Imoto, Tetsuo Hino, Satoru Nishioka
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Publication number: 20170102633Abstract: An electrophotographic electro-conductive member comprising an electro-conductive mandrel and an electro-conductive elastic layer on the electro-conductive mandrel, wherein the electro-conductive elastic layer has an elastic coefficient of 1 MPa or more and 100 MPa or less, as well as a matrix containing first rubber and a plurality of electro-conductive domains dispersed in the matrix. Each of the electro-conductive domains contains an electro-conductive particle, and the electro-conductive elastic layer includes regions containing second rubber in the circumferences of the electro-conductive domains. The matrix has an elastic coefficient R1, the regions containing second rubber have an elastic coefficient R2, and the elastic coefficients R1 and R2 satisfy a relationship: R1<R2.Type: ApplicationFiled: October 4, 2016Publication date: April 13, 2017Inventors: Takeshi Yoshidome, Saki Tominaga, Yasuhiro Fushimoto, Norifumi Muranaka, Kazuhiro Yamauchi
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Patent number: 9551949Abstract: To suppress an image trouble resulting from abnormal discharge independent of the use conditions and use environment of an electroconductive member, provided is an electroconductive member to be used while being brought into contact with a body to be contacted, the electroconductive member comprising a layer of a network structural body on an outer peripheral surface of a electroconductive support, in which: when a surface of the network structural body in a surface of the electroconductive member is observed, at least a part of the network structural body exists in an arbitrary square region having one side length of 200 ?m; the network structural body contains non-electroconductive fibers; and an average fiber diameter of a top 10% of fiber diameters of the non-electroconductive fibers measured at arbitrary points is 0.2 ?m or more and 15 ?m or less.Type: GrantFiled: March 24, 2015Date of Patent: January 24, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Kazuhiro Yamauchi, Satoru Yamada, Norifumi Muranaka, Yuichi Kikuchi, Tetsuo Hino
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Electroconductive member for electrophotography, process cartridge and electrophotographic apparatus
Patent number: 9547250Abstract: The present invention relates to an electroconductive member including an electroconductive support layer and a surface layer formed on a circumference thereof and having a network structure containing fibers, in which an arithmetic mean value dU10 of top 10% fiber diameters is 0.2 ?m or more and 15.0 ?m or less, rigid structural body having a height of 1.0×10?2 to 1.0×101 times as large as a thickness of the surface layer are present on the outer circumferential portion of the electroconductive support layer, and the surface layer satisfies specific conditions.Type: GrantFiled: March 23, 2015Date of Patent: January 17, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Norifumi Muranaka, Satoru Yamada, Tetsuo Hino -
Patent number: 9541854Abstract: Provided is an electroconductive member configured to suppress a void image caused by abnormal discharge and a horizontal streak-like image caused by downstream discharge without depending on the thickness of a photosensitive layer of a photosensitive drum over a long period of time. The electroconductive member for electrophotography comprises at least an electroconductive support and a surface layer formed on an outer side of the electroconductive support. The surface layer includes a porous body and satisfies the predetermined (1), (2), and (3).Type: GrantFiled: March 23, 2015Date of Patent: January 10, 2017Assignee: CANON KABUSHIKI KAISHAInventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Mikio Shimada, Tetsuo Hino, Masahiro Watanabe, Norifumi Muranaka, Satoru Nishioka
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Publication number: 20160054674Abstract: Provided is such a conductive member that a change in its electrical resistance value caused by its long-term use is reduced to the extent possible. The conductive member has a conductive support and a conductive layer, the conductive layer contains a rubber composition formed of a modified epichlorohydrin rubber, and the modified epichlorohydrin rubber has a unit represented by the following formula (1). In the formula (1), R1, R2, and R3 each independently represent hydrogen or a saturated hydrocarbon group having 1 to 18 carbon atoms.Type: ApplicationFiled: November 3, 2015Publication date: February 25, 2016Inventors: Norifumi Muranaka, Satoru Yamada, Kazuhiro Yamauchi, Seiji Tsuru, Yuka Muranaka
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Patent number: 9146482Abstract: It is an object of the present invention to provide an electroconductive member for electrophotography capable of suppressing image density unevenness caused by the adhesion of foreign matter. Provided is an electroconductive member for electrophotography, including at least: an electroconductive support, and a surface layer formed on an outer side of the electroconductive support, in which the surface layer includes a porous body, and in which the porous body satisfies the following conditions (1) to (3): (1) the porous body has a co-continuous structure including at least a skeleton that is three-dimensionally continuous and a pore that is three-dimensionally continuous; (2) the porous body has electroconductivity; and (3) an average diameter of a maximum inscribed circle of an opening of the pore on a surface of the porous body is 3 ?m or more and 8 ?m or less.Type: GrantFiled: January 21, 2015Date of Patent: September 29, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Masahiro Watanabe, Yuichi Kikuchi, Kazuhiro Yamauchi, Satoru Nishioka, Norifumi Muranaka, Mikio Shimada, Tetsuo Hino
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Patent number: 9128403Abstract: The present invention provides an electrophotographic electrically conductive member in which conductivity needed for a charging member is secured, and defects in an image attributed to uneven discharging can be minimized independently of a long-term use and an environment of use. An electrophotographic electrically conductive member comprising an electrically conductive support and an electrically conductive layer, wherein the electrically conductive layer includes an ion conductive resin having a quaternary ammonium ion in a molecule structure as a binder resin, and a carrier molecule represented by the following formula (1) or (2): (wherein n1 and n2 each independently represent an integer of 1 to 4).Type: GrantFiled: February 25, 2014Date of Patent: September 8, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Kazuhiro Yamauchi, Norifumi Muranaka, Satoru Nishioka, Yuichi Kikuchi
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Patent number: 9086643Abstract: Provided is an electro-conductive member for electrophotography that stably shows high electro-conductivity even under a low-temperature, low-humidity environment. The electro-conductive member for electrophotography has an electro-conductive mandrel and an electro-conductive layer. The electro-conductive layer contains an ionic electro-conductive resin and an ion carrier. The ionic electro-conductive resin has at least one structure selected from the group consisting of structures represented by the following formulae (1), (2), (3), and (4), and a structure represented by the following formula (5) (in the formula (1) to the formula (5), R1, R2, R3, and R4 each represent a divalent organic group, X1, X2, X3, and X4 each independently represent a sulfonic group or a quaternary ammonium base, and 1 represents an integer of 1 or more and 23 or less).Type: GrantFiled: July 17, 2012Date of Patent: July 21, 2015Assignee: CANON KABUSHIKI KAISHAInventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Norifumi Muranaka, Satoru Nishioka
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Publication number: 20150198905Abstract: Provided is an electroconductive member configured to suppress a void image caused by abnormal discharge and a horizontal streak-like image caused by downstream discharge without depending on the thickness of a photosensitive layer of a photosensitive drum over a long period of time. The electroconductive member for electrophotography comprises at least an electroconductive support and a surface layer formed on an outer side of the electroconductive support. The surface layer includes a porous body and satisfies the predetermined (1), (2), and (3).Type: ApplicationFiled: March 23, 2015Publication date: July 16, 2015Inventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Mikio Shimada, Tetsuo Hino, Masahiro Watanabe, Norifumi Muranaka, Satoru Nishioka
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ELECTROCONDUCTIVE MEMBER FOR ELECTROPHOTOGRAPHY, PROCESS CARTRIDGE AND ELECTROPHOTOGRAPHIC APPARATUS
Publication number: 20150198904Abstract: The present invention relates to an electroconductive member including an electroconductive support layer and a surface layer formed on a circumference thereof and having a network structure containing fibers, in which an arithmetic mean value dU10 of top 10% fiber diameters is 0.2 ?m or more and 15.0 ?m or less, rigid structural body having a height of 1.0×10?2 to 1.0×101 times as large as a thickness of the surface layer are present on the outer circumferential portion of the electroconductive support layer, and the surface layer satisfies specific conditions.Type: ApplicationFiled: March 23, 2015Publication date: July 16, 2015Inventors: Yuichi Kikuchi, Kazuhiro Yamauchi, Norifumi Muranaka, Satoru Yamada, Tetsuo Hino