Patents by Inventor Yuji Sakurai

Yuji Sakurai 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: 8182405
    Abstract: A developing roller is provided which supplies a toner to a photosensitive member to develop an electrostatic latent image formed on the photosensitive member. The developing roller has a surface layer which includes carbon black and a polyurethane resin. The polyurethane resin has a specific structure. The surface layer has a specific ester group concentration and a specific urethane group concentration.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: May 22, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahiro Kurachi, Masaki Yamada, Yuji Sakurai, Minoru Nakamura
  • Publication number: 20110183080
    Abstract: An object of the present invention is to provide a production process of a roller for an electrophotography, having a surface layer the electric resistance of which has been controlled by corona discharge treatment while keeping any pinholes from coming about on the surface. A production process of a roller for an electrophotography, said roller comprising a conductive mandrel and a conductive surface layer comprising a resin and carbon black dispersed in the resin, the process having the following steps (1) to (3): (1) forming a resin layer comprising a resin and carbon black dispersed therein on the circumference of the conductive mandel; (2) attaching silica particles on the surface of the resin layer; and (3) subjecting corona discharge treatment to the surface of the resin layer on which the silica particles are attached.
    Type: Application
    Filed: April 6, 2011
    Publication date: July 28, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kunimasa Kawamura, Yuji Sakurai, Shohei Urushihara
  • Patent number: 7979004
    Abstract: The electrophotographic belt of the present invention is characterized that, in the electrophotographic belt composed of the thermoplastic resin composition containing thermoplastic resin, with respect to a flake-shaped portion having an arc length of 5% of the inner peripheral length of the electrophotographic belt, when the thickness of the flake-shaped portion is measured at intervals of 1 mm in the peripheral direction, the difference between the maximum value and the minimum value of the measured value is 2% or more and 20% or less of an arithmetic average value.
    Type: Grant
    Filed: February 2, 2006
    Date of Patent: July 12, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsushi Tanaka, Takashi Kusaba, Hidekazu Matsuda, Yuji Sakurai, Akihiko Nakazawa
  • Publication number: 20100080611
    Abstract: A developing roller is provided which supplies a toner to a photosensitive member to develop an electrostatic latent image formed on the photosensitive member. The developing roller has a surface layer which includes carbon black and a polyurethane resin. The polyurethane resin has a specific structure. The surface layer has a specific ester group concentration and a specific urethane group concentration.
    Type: Application
    Filed: September 11, 2009
    Publication date: April 1, 2010
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masahiro Kurachi, Masaki Yamada, Yuji Sakurai, Minoru Nakamura
  • Patent number: 7439436
    Abstract: A main case body of a musical instrument, which is capable of securing a degree of freedom of design. A case structure includes a lower front case, a lower rear case, and an upper case. The lower front case has a keyboard unit mounted therein. A bottom part extends in a front-rear direction of the lower front case. A key supporting part is formed such that it rises from the rear of the bottom part of the lower front case and extends in the key arrangement direction. A stopper body for stopping a free end of each key is formed such that it rises from the front of the bottom part of the lower front case and extends in the key arrangement direction. A battery case is formed by six battery terminal-associated parts arranged side by side for batteries between the key support part and the stopper body.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: October 21, 2008
    Assignee: Yamaha Corporation
    Inventor: Yuji Sakurai
  • Patent number: 7425672
    Abstract: An exterior structure for a keyboard instrument, which is capable of dramatically increasing the variation of producible types of keyboard instruments while suppressing the cost of molds. A lower case includes a front-side lower case LCf and a rear-side lower case LCr disposed rearward of the front-side lower case LCf in a side-by-side fashion. An upper case UC is disposed above the lower case. The front-side lower case LCf is fastened to the upper case UC, and the rear-side lower case LCr is fastened to the upper case UC, whereby the lower case is secured to the upper case UC.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: September 16, 2008
    Assignee: Yamaha Corporation
    Inventors: Daisuke Haba, Yuji Sakurai, Masao Sato, Toshiyuki Aiba
  • Patent number: 7352984
    Abstract: An electrophotographic endless belt containing a polyamide resin, carbon black and a filler, characterized in that the polyamide resin is at least one resin selected from the group consisting of polyamide 610, polyamide 612, polyamide 11 and polyamide 12, the filler is at least one filler selected from the group consisting of an oxide, a hydroxide, a carbonate and a silicate, and weight (A) of the polyamide resin and total weight (B) of the carbon black and the filler is in a ratio (A:B) of from 90:10 to 50:50. Also disclosed are an electrophotographic apparatus having the electrophotographic endless belt, and a process for producing the electrophotographic endless belt.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: April 1, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidekazu Matsuda, Akihiko Nakazawa, Atsushi Tanaka, Takashi Kusaba, Yuji Sakurai
  • Patent number: 7201967
    Abstract: In an electrophotographic endless belt having a resin layer formed of a resin composition containing a polyamide, the resin composition further contains a copolymer obtained by copolymerization of an olefin and an oxygen-containing heterocyclic compound, a curve (T-log10 ? curve) showing the relationship between temperature T (° C.) and common logarithm log10 ? of melt viscosity ? (Pa·s), of the resin composition has, in the range of log10 ? of from log10 1,000 to log10 8,000, a gently inclined region the inclination ? log10 ?/?T of which is from ?0.02 to 0, and the gently inclined region has a temperature range of 10° C. or more, and the resin layer has a thickness the maximum thickness of which is 115% or less of the average value of the thickness of the resin layer and the minimum thickness of which is 85% or more of the average value of the thickness of the resin layer. Also disclosed is a process for producing the above electrophotographic endless belt.
    Type: Grant
    Filed: November 24, 2004
    Date of Patent: April 10, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuji Sakurai, Akihiko Nakazawa, Atsushi Tanaka, Hidekazu Matsuda, Takashi Kusaba
  • Publication number: 20060226572
    Abstract: An electrophotographic endless belt is disclosed having a layer formed of a resin composition containing (i) at least one resin selected from the group consisting of a polyether ester amide, a polyolefin ether and a polyether amide; (ii) polyvinylidene fluoride; and (iii) carbon. In the resin composition, the ratio of the mass of the component (iii) to the mass of the component (i) is in a specific range.
    Type: Application
    Filed: December 23, 2005
    Publication date: October 12, 2006
    Applicant: Canon Kabushiki Kaisha
    Inventors: Atsushi Tanaka, Akihiko Nakazawa, Takashi Kusaba, Hidekazu Matsuda, Kenichi Yamauchi, Yuji Sakurai, Norifumi Muranaka
  • Publication number: 20060137508
    Abstract: A main case body of a musical keyboard instrument, which is capable of securing a degree of freedom of design. A case structure comprises a lower front case, a lower rear case, and an upper case. The lower front case has a keyboard unit mounted therein. A bottom part extends in a front-rear direction of the lower front case. A key supporting part is formed such that it rises from the rear of the bottom part of the lower front case and extends in the key arrangement direction, and supports each of the keys of the keyboard unit at a base end of the key. A stopper body is formed such that it rises from the front of the bottom part of the lower front case and extends in the key arrangement direction, and stops a free end of each of the keys of the keyboard unit when the key is operated. A battery case is formed by six battery terminal-associated parts arranged side by side for batteries between the key supporting part and the stopper body.
    Type: Application
    Filed: December 21, 2005
    Publication date: June 29, 2006
    Applicant: Yamaha Corporation
    Inventor: Yuji Sakurai
  • Publication number: 20060137509
    Abstract: An exterior structure for a keyboard instrument, which is capable of dramatically increasing the variation of producible types of keyboard instruments while suppressing the cost of molds. A lower case includes a front-side lower case LCf and a rear-side lower case LCr disposed rearward of the front-side lower case LCf in a side-by-side fashion. An upper case UC is disposed above the lower case. The front-side lower case LCf is fastened to the upper case UC, and the rear-side lower case LCr is fastened to the upper case UC, whereby the lower case is secured to the upper case UC.
    Type: Application
    Filed: December 23, 2005
    Publication date: June 29, 2006
    Applicant: Yamaha Corporation
    Inventors: Daisuke Haba, Yuji Sakurai, Masao Sato, Toshiyuki Aiba
  • Publication number: 20060127617
    Abstract: The electrophotographic belt of the present invention is characterized that, in the electrophotographic belt composed of the thermoplastic resin composition containing thermoplastic resin, with respect to a flake-shaped portion having an arc length of 5% of the inner peripheral length of the electrophotographic belt, when the thickness of the flake-shaped portion is measured at intervals of 1 mm in the peripheral direction, the difference between the maximum value and the minimum value of the measured value is 2% or more and 20% or less of an arithmetic average value.
    Type: Application
    Filed: February 2, 2006
    Publication date: June 15, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Atsushi Tanaka, Takashi Kusaba, Hidekazu Matsuda, Yuji Sakurai, Akihiko Nakazawa
  • Publication number: 20060067747
    Abstract: An electrophotographic endless belt which contains a polyamide resin and an additive A comprising at least one selected from the group consisting of copper(I) iodide, potassium iodide, copper(I) chloride and potassium chloride, and has a volume resistivity of from 1×106 to 1×1014 ?cm. Also disclosed are a process for producing the electrophotographic endless belt and an electrophotographic apparatus having the electrophotographic endless belt.
    Type: Application
    Filed: September 15, 2005
    Publication date: March 30, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hidekazu Matsuda, Akihiko Nakazawa, Atsushi Tanaka, Takashi Kusaba, Yuji Sakurai
  • Publication number: 20050142368
    Abstract: In an electrophotographic endless belt having a resin layer formed of a resin composition containing a polyamide, the resin composition further contains a copolymer obtained by copolymerization of an olefin and an oxygen-containing heterocyclic compound, a curve (T?log10? curve) showing the relationship between temperature T (° C.) and common logarithm log10? of melt viscosity ? (Pa·s), of the resin composition has, in the range of log10? of from log10 1,000 to log10 8,000, a gently inclined region the inclination ?log10?/?T of which is from ?0.02 to 0, and the gently inclined region has a temperature range of 10° C. or more, and the resin layer has a thickness the maximum thickness of which is 115% or less of the average value of the thickness of the resin layer and the minimum thickness of which is 85% or more of the average value of the thickness of the resin layer. Also disclosed is a process for producing the above electrophotographic endless belt.
    Type: Application
    Filed: November 24, 2004
    Publication date: June 30, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Yuji Sakurai, Akihiko Nakazawa, Atsushi Tanaka, Hidekazu Matsuda, Takashi Kusaba
  • Publication number: 20050118522
    Abstract: An electrophotographic endless belt containing a polyamide resin, carbon black and a filler, characterized in that the polyamide resin is at least one resin selected from the group consisting of polyamide 610, polyamide 612, polyamide 11 and polyamide 12, the filler is at least one filler selected from the group consisting of an oxide, a hydroxide, a carbonate and a silicate, and weight (A) of the polyamide resin and total weight (B) of the carbon black and the filler is in a ratio (A:B) of from 90:10 to 50:50. Also disclosed are an electrophotographic apparatus having the electrophotographic endless belt, and a process for producing the electrophotographic endless belt.
    Type: Application
    Filed: November 12, 2004
    Publication date: June 2, 2005
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hidekazu Matsuda, Akihiko Nakazawa, Atsushi Tanaka, Takashi Kusaba, Yuji Sakurai
  • Patent number: 6856776
    Abstract: An electrophotographic endless belt has a belt-like substrate, and a meandering-preventive member for preventing the electrophotographic endless belt from meandering and a position detection member for detecting a prescribed position of the electrophotographic endless belt. The meandering preventive member is, disposed on the inner-periphery side of one end portion of the belt-like substrate, and the position detection member is disposed on the outer-periphery side of the other end portion of the belt-like substrate. The meandering-preventive member and the position detection member are kept apart by a distance of from 200 mm to 250 mm in the width direction of the electrophotographic endless belt. A process cartridge and an electrophotographic apparatus employ such an electrophotographic endless belt as an intermediate transfer belt.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: February 15, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hidekazu Matsuda, Hiroyuki Kobayashi, Akihiko Nakazwa, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Ryota Kashiwabara, Yuji Sakurai
  • Patent number: 6853824
    Abstract: In an electrophotographic endless belt having a beltlike substrate, a meandering-preventive member and a position detection member, the meandering-preventive member is disposed on the inner-periphery side of one end portion of the beltlike substrate, the position detection member is disposed on the outer-periphery side of the other end portion of the beltlike substrate, and the meandering-preventive member and the position detection member are 200 mm to 250 mm away from each other in the width direction of the electrophotographic endless belt. The beltlike substrate contains a thermoplastic resin as a binder resin, and the beltlike substrate has a 25 ?m×25 ?m surface total current value of from 300 nA to 2,000 nA at the time of application of 100 V as measured by SPM.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: February 8, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ryota Kashiwabara, Hiroyuki Kobayashi, Akihiko Nakazawa, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda, Yuji Sakurai
  • Patent number: 6795667
    Abstract: A process cartridge which is detachably mountable to a main body of an electrophotographic apparatus, includes an electrophotographic photosensitive member to carry a toner image; an intermediate transfer belt having a contact part with the photosensitive member, and a primary transfer unit to primarily transfer the toner image at the contact part from the photosensitive member to the intermediate transfer belt, being integrally supported in one body. After the contact part is formed by the photosensitive member and the intermediate transfer belt is brought into contact with under a linear pressure of 0.5 N/cm and is left for 10 hours in an environment of 45° C.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: September 21, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda, Yuji Sakurai
  • Patent number: 6766127
    Abstract: A process cartridge detachably mountable on the main body of an electrophotographic apparatus, integrally supports a photosensitive drum for bearing toner images, and an intermediate transferring belt having a contact part with the photosensitive drum. The moisture amount of the intermediate transferring belt at 23° C./50% RH is less than 1% by weight and the sum of the surface roughness Ra of the photosensitive drum and the surface roughness Ra of the intermediate transferring belt is less than 0.8 &mgr;m. The present invention also provides an electrophotographic apparatus having the process cartridge and an image forming method using the electrophotographic apparatus.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: July 20, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsushi Tanaka, Hiroyuki Kobayashi, Akihiko Nakazawa, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda, Yuji Sakurai
  • Patent number: 6725002
    Abstract: A process cartridge detachably mountable to the electrophotographic apparatus main body, integrally including an electrophotographic photosensitive member to carry a toner image; an intermediate transfer belt having a contact part with the photosensitive member; primary transfer member to primarily transfer the toner image from the photosensitive member to the intermediate transfer belt; and electric charge member to give electric charges in polarity opposite to the polarity of the toner at the time of the primary transfer to the toner on the intermediate transfer belt to return the toner on the intermediate transfer belt to the photosensitive member at the contact part to clean the intermediate transfer belt, wherein the intermediate transfer belt has an average glossiness of 30 to 90; glossiness deviation within 10; average film thickness of 40 to 200 &mgr;m; and film thickness unevenness within ±20% relative to the average film thickness.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: April 20, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuji Sakurai, Hiroyuki Kobayashi, Akihiko Nakazawa, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda