Patents by Inventor Minoru Shimojo

Minoru Shimojo 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: 20070014943
    Abstract: A process is disclosed producing an intermediate transfer member used in an image-forming apparatus in which an image formed on a first image-bearing member is transferred to a second image-bearing member. The process has the steps of melt-extruding an extrusion material from a circular die by means of an extruder and thereafter making the same into a desired shape to obtain a cylindrical extruded product, and forming the resultant cylindrical extruded product into the intermediate transfer member. The cylindrical extruded product contains a thermoplastic resin and an ion-conductive resistance control agent, and a ratio of the diameter of the intermediate transfer member obtained to the die diameter of the circular die is from 0.5 to 4.0. Also disclosed are an intermediate transfer member obtained by the production process, and an intermediate transfer member having the intermediate transfer member.
    Type: Application
    Filed: September 19, 2006
    Publication date: January 18, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Minoru Shimojo, Hiroyuki Kobayashi, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Patent number: 6852400
    Abstract: An endless belt for electrophotography is disclosed which is obtainable continuously by melt extrusion from a circular die. The endless belt has a layer containing a thermoplastic resin having a diphenyl sulfone structure represented by the following Formula (1) Also disclosed are a process for producing the endless belt and an image forming apparatus having the endless belt.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: February 8, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Minoru Shimojo, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Patent number: 6846601
    Abstract: In a negatively chargeable toner having i) negatively chargeable toner particles containing at least a binder resin, a colorant and a vinyl copolymer and ii) an inorganic fine powder, the negatively chargeable toner has a weight-average particle diameter of from 4 ?m to 12 ?m and contains, in particle size distribution of the toner, less than 50% by volume of particles of 10.1 ?m or more in particle diameter, and the vinyl copolymer is a vinyl copolymer obtained by copolymerizing a monomer composition which contains at least i) a vinyl monomer such as an N-substituted acryl- or methacrylamide or a ring-structure acryl- or methacrylamide and ii) a vinyl monomer having as a functional group a carboxyl group or a carboxyl group made into salt structure. An image-forming method and a process cartridge make use of such a negatively chargeable toner.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: January 25, 2005
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minoru Shimojo, Satoshi Matsunaga
  • Publication number: 20040124568
    Abstract: A method for producing an endless belt for electrophotography by melt-extruding a thermoplastic resin having a diphenyl sulfone structure represented by the following Formula (1) from a circular die to produce the endless belt continuously 1
    Type: Application
    Filed: December 16, 2003
    Publication date: July 1, 2004
    Applicant: Canon Kabushiki Kaisha
    Inventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Minoru Shimojo, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Publication number: 20030224275
    Abstract: In a negatively chargeable toner having i) negatively chargeable toner particles containing at least a binder resin, a colorant and a vinyl copolymer and ii) an inorganic fine powder, the negatively chargeable toner has a weight-average particle diameter of from 4 &mgr;m to 12 &mgr;m and contains, in particle size distribution of the toner, less than 50% by volume of particles of 10.1 &mgr;m or more in particle diameter, and the vinyl copolymer is a vinyl copolymer obtained by copolymerizing a monomer composition which contains at least i) a vinyl monomer such as an N-substituted acryl- or methacrylamide or a ring-structure acryl- or methacrylamide and ii) a vinyl monomer having as a functional group a carboxyl group or a carboxyl group made into salt structure. An image-forming method and a process cartridge make use of such a negatively chargeable toner.
    Type: Application
    Filed: March 10, 2003
    Publication date: December 4, 2003
    Inventors: Minoru Shimojo, Satoshi Matsunaga
  • Patent number: 6592803
    Abstract: A process produces a belt-shaped member to be used in an image-forming apparatus is disclosed in which a toner image held on a latent-image-bearing member is electrostatically transferred under application of a voltage via the belt-shaped transfer member. The process includes the steps of melt-extruding a material containing a thermoplastic resin, from a circular die into a cylindrical film; forming the resultant cylindrical film by stretching in such a way that the cylindrical film comes to have a thickness smaller than the die gap of the circular die; and cutting the cylindrical film thus formed, into a seamless belt having a thickness of from 40 &mgr;m to 300 &mgr;m and a modulus in tension of 600 MPa or higher. The stretched cylindrical film is formed to have a thickness not larger than ⅓ of the die gap of the circular die. A belt-shaped transfer member may be produced by the above-described process.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: July 15, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Minoru Shimojo, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Patent number: 6541174
    Abstract: A toner for developing an electrostatic image is formed of toner particles; wherein each toner particle includes (i) 100 wt. parts of a binder resin having a glass transition point (Tg) of 50-70° C., (ii) 0.2-20 wt. parts of solid wax, and (iii) colorant particles or magnetic powder; (iv) lubricant particles carrying a liquid lubricant, so that the toner particle retains at its surface the liquid lubricant gradually released from the particles (iv). The toner may be further blended with an organically treated inorganic fine powder to provide a developer. The toner or developer retains good lubricity and releasability so that it is suitable to be used in an image forming method including means contacting a latent image-bearing means, such as a contact charging means, a contact transfer means or a contact cleaning means.
    Type: Grant
    Filed: September 1, 2000
    Date of Patent: April 1, 2003
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hirohide Tanikawa, Toshiaki Nakahara, Keita Nozawa, Kazuyoshi Hagiwara, Minoru Shimojo, Rika Shinba, Masami Fujimoto, Tsutomu Onuma
  • Publication number: 20020176977
    Abstract: An endless belt for electrophotography is disclosed which is obtainable continuously by melt extrusion from a circular die.
    Type: Application
    Filed: December 21, 1999
    Publication date: November 28, 2002
    Inventors: AKIHIKO NAKAZAWA, HIROYUKI KOBAYASHI, MINORU SHIMOJO, AKIRA SHIMADA, ATSUSHI TANAKA, TSUNENORI ASHIBE, TAKASHI KUSABA, HIDEKAZU MATSUDA
  • Publication number: 20020054971
    Abstract: A process is disclosed producing an intermediate transfer member used in an image-forming apparatus in which an image formed on a first image-bearing member is transferred to a second image-bearing member. The process has the steps of melt-extruding an extrusion material from a circular die by means of an extruder and thereafter making the same into a desired shape to obtain a cylindrical extruded product, and forming the resultant cylindrical extruded product into the intermediate transfer member. The cylindrical extruded product contains a thermoplastic resin and an ion-conductive resistance control agent, and a ratio of the diameter of the intermediate transfer member obtained to the die diameter of the circular die is from 0.5 to 4.0. Also disclosed are an intermediate transfer member obtained by the production process, and an intermediate transfer member having the intermediate transfer member.
    Type: Application
    Filed: September 14, 2001
    Publication date: May 9, 2002
    Inventors: Minoru Shimojo, Hiroyuki Kobayashi, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Publication number: 20020006573
    Abstract: A process for producing a belt-shaped transfer member to be used in an image-forming apparatus is disclosed in which a toner image held on a latent-image-bearing member is electrostatically transferred under application of a voltage via the belt-shaped transfer member. The process comprises the steps of melt-extruding a material containing a thermoplastic resin, from a circular die into a cylindrical film; forming the resultant cylindrical film by stretching in such a way that the cylindrical film comes to have a thickness smaller than the die gap of the circular die; and cutting the cylindrical film thus formed, into a seamless belt having a thickness of from 40 &mgr;m to 300 &mgr;m and a modulus in tension of 600 MPa or higher. Also disclosed is a belt-shaped transfer member produced by this process.
    Type: Application
    Filed: December 29, 2000
    Publication date: January 17, 2002
    Inventors: Akihiko Nakazawa, Hiroyuki Kobayashi, Minoru Shimojo, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Patent number: 6303072
    Abstract: A process for producing an endless belt includes melt-extruding an extrusion material into a cylinder by means of an extruder, where the extrusion material has a tensile break strength of 400 kgf/cm2 or above and a breaking extension of from 3.0% to 250%, and where the extrusion material is extruded in an extrusion ratio of from 1.05 to 2.80 while a gas is blown into the inside of the melt-extruded cylindrical product.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: October 16, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroyuki Kobayashi, Minoru Shimojo, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe, Takashi Kusaba, Hidekazu Matsuda
  • Patent number: 6187496
    Abstract: A toner for developing an electrostatic image is formed of toner particles; wherein each toner particle includes (i) 100 wt. parts of a binder resin having a glass transition point (Tg) of 50-70° C., (ii) 0.2-20 wt. parts of solid wax, and (iii) colorant particles or magnetic powder, (iv) lubricant particles carrying a liquid lubricant, so that the toner particle retains at its surface the liquid lubricant gradually released from the particles (iv). The toner may be further blended with an organically treated inorganic fine powder to provide a developer. The toner or developer retains good lubricity and releasability so that it is suitable to be used in an image forming method including means contacting a latent image-bearing means, such as a contact charging means, a contact transfer means or a contact cleaning means.
    Type: Grant
    Filed: March 20, 1997
    Date of Patent: February 13, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hirohide Tanikawa, Toshiaki Nakahara, Keita Nozawa, Kazuyoshi Hagiwara, Minoru Shimojo, Rika Shinba, Masami Fujimoto, Tsutomu Onuma
  • Patent number: 6144830
    Abstract: An intermediate transfer member is formed by at least a base layer and a surface layer. The base layer is formed by epichlorohydrin rubber and acrylonitrile-butadiene rubber mixed in a certain weight ratio (preferably 1:9 to 9:1). The surface layer is formed by urethane resin or elastomer and a fluorine-containing compound powder. The fluorine-containing compound powder may preferably be contained in an amount of 20-80 wt. % based on the surface layer. The intermediate transfer member is suitable for full-color image formation by electrophotography and is effective in improving a transfer performance and providing clear images without causing transfer failure even in repetitive use for a long period.
    Type: Grant
    Filed: January 9, 1997
    Date of Patent: November 7, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Kusaba, Hiroyuki Kobayashi, Minoru Shimojo, Akihiko Nakazawa, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe
  • Patent number: 6094556
    Abstract: An intermediate transfer member for receiving a toner image formed on a first image-bearing member and transferring the toner image onto a second image-bearing member has a surface coated with at least one of a nitrate ion adsorbent and a compound having a layer structure, whereby a scattering of toner particles during a successive image formation is effectively suppressed for a long period.
    Type: Grant
    Filed: January 29, 1999
    Date of Patent: July 25, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsushi Tanaka, Minoru Shimojo, Akira Shimada, Hiroyuki Osada, Tsunenori Ashibe, Hidekazu Matsuda
  • Patent number: 6077638
    Abstract: A toner for developing an electrostatic image is formed of toner particles; wherein each toner particle includes (i) 100 wt. parts of a binder resin having a glass transition point (Tg) of 50-70.degree. C., (ii) 0.2-20 wt. parts of solid wax, and (iii) colorant particles or magnetic powder carrying a liquid lubricant, so that the toner particle retains at its surface the liquid lubricant gradually released from the particles (iii). The toner may be further blended with an organically treated inorganic fine powder to provide a developer. The toner or developer retains good lubricity and releasability so that it is suitable to be used in an image forming method including means contacting a latent image-bearing means, such as a contact charging means, a contact transfer means or a contact cleaning means.
    Type: Grant
    Filed: March 21, 1997
    Date of Patent: June 20, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hirohide Tanikawa, Toshiaki Nakahara, Keita Nozawa, Kazuyoshi Hagiwara, Minoru Shimojo, Rika Shinba, Masami Fujimoto, Tsutomu Onuma
  • Patent number: 6078773
    Abstract: An image forming apparatus has a first image bearing member and an intermediate transfer member onto which a toner image formed on the first image bearing member is primarily transferred and through which the toner image thus transferred is secondarily transferred onto a second image bearing member. The intermediate transfer member has a surface layer on a base layer and the surface layer contains a polyurethane resin obtained by the reaction of an olefinpolyol with an isocyanate.
    Type: Grant
    Filed: February 12, 1998
    Date of Patent: June 20, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Minoru Shimojo, Akira Shimada, Hiroyuki Osada, Atsushi Tanaka, Tsunenori Ashibe
  • Patent number: 5995794
    Abstract: An image forming apparatus has a first image bearing member and an intermediate transfer belt onto which a toner image formed on the first image bearing member is primarily transferred is secondarily tranferred onto a second image bearing member. The intermediate tranfer belt has, in its non-image forming region, a tape having a volume resistivity of 10.sup.10 .OMEGA..multidot.cm or above, a bond strength of 0.5 kg or above and a breaking extension of 5% or more.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: November 30, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroyuki Osada, Minoru Shimojo, Akira Shimada, Atsushi Tanaka, Tsunenori Ashibe
  • Patent number: 5978638
    Abstract: The present invention concerns an image forming apparatus for forming a toner image on a transfer medium by use of an intermediate transfer belt, and also the intermediate transfer belt itself. The intermediate transfer belt has an elastic layer JIS-A hardness of which is 85.degree. or less and at least one covering layer formed on the elastic layer. A relative permittivity .epsilon. and thickness t (.mu.m) of the at least one covering layer satisfy relations of .epsilon..ltoreq.6 and t.gtoreq..epsilon., and the intermediate transfer belt includes a fiber. The effects of this .epsilon. value and the fiber inside enabled to suppress scattering of toner well.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: November 2, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsushi Tanaka, Minoru Shimojo, Akira Shimada, Hiroyuki Osada, Tsunenori Ashibe
  • Patent number: 5605778
    Abstract: A toner for developing electrostatic images is prepared from a binder resin, a colorant or magnetic material, and a wax component. The toner is provided with improved low-temperature fixability anti-electrostatic offset characteristic, anti-blocking characteristic and anti-offset characteristic by controlling the thermal characteristic of the wax component so as to provide a DSC (differential scanning colorimeter) curve on temperature increase, showing a minimum onset temperature of heat absorption of at least 50.degree. C. and at least two heat absorption peaks including a largest and a second largest peaks, different from each other in peak temperature by at least 15.degree. C., wherein low-temperature heat absorption peak P.sub.1 of the two peaks shows a half-value width of at most 20.degree. C. and a higher-temperature heat absorption peak P.sub.2 shows a half-value width of at most 20.degree. C., and wherein the peak P.sub.1 shows a higher half-width temperature and the peak P.sub.
    Type: Grant
    Filed: April 3, 1996
    Date of Patent: February 25, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Onuma, Satoshi Matsunaga, Manabu Ohno, Minoru Shimojo
  • Patent number: 5447813
    Abstract: A toner for developing an electrostatic image is composed by a binder resin, and a magnetic material and/or a colorant. The binder resin (a) comprises a styrene resin polymerized in the presence of a poly-functional polymerization initiator, (b) provides a molecular weight distribution on a GPC chromatogram showing a maximum (P1) in a molecular weight range of 3.5.times.10.sup.3 -5.times.10.sup.4 and a maximum (P2) or shoulder in a molecular weight range of at least 1.times.10.sup.5, and (c) contains 15 wt. % or less of a resin component in a molecular weight range of at most 3.times.10.sup.3. Further the toner contains at most 100 ppm of styrene and benzaldehyde.
    Type: Grant
    Filed: December 2, 1994
    Date of Patent: September 5, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuyoshi Hagiwara, Toshiaki Nakahara, Minoru Shimojo, Masami Fujimoto, Kiyoshi Mizoe