Patents by Inventor Makoto Kanbayashi

Makoto Kanbayashi 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: 5512402
    Abstract: A carrier for electrophotography has carrier particles. The carrier has a 50% average particle diameter (D.sub.50) of from 15 .mu.m to 45 .mu.m and contains from 1% to 20% of carrier particles with a size smaller than 22 .mu.m, not more than 3% of carrier particles with a size smaller than 16 .mu.m, from 2% to 15% of carrier particles with a size of 62 .mu.m or larger, and not more than 2% of carrier particles with a size of 88 .mu.m or larger. The carrier has a specific surface area S.sub.1 as measured by an air-permeability method and a specific surface area S.sub.2 as calculated by the following expression:S.sub.2 =(6/.rho..D.sub.50).times.10.sup.4wherein .rho. is a specific gravity of carrier; satisfying the following condition:1.2.ltoreq.S.sub.1 /S.sub.2 .ltoreq.2.0.
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: April 30, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Makoto Kanbayashi, Tsuyoshi Takiguchi, Yasuhiro Ichikawa, Wakashi Iida
  • Patent number: 5500321
    Abstract: A color toner for developing electrostatic images is formed of color toner particles each including a binder resin, a polyalkylene, and a colorant. The color toner particles are formed by suspension polymerization. The polyalkylene is characterized by having a crystallinity of 10-50% and a melting enthalpy (as measured by a differential scanning calorimeter) of at most 35 cal/g. The color toner is characterized by an improved fixability without causing offset especially at a relatively low temperature and suitable for providing a transparency film for an overhead projection.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: March 19, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashige Kasuya, Takayuki Nagatsuka, Tatsuya Nakamura, Makoto Kanbayashi, Tatsuhiko Chiba
  • Patent number: 5476745
    Abstract: The present invention provides a process for producing a toner having little remaining polymerizable monomer in it by suspension polymerization. During the latter half of the polymerization reaction, the remaining polymerizable monomers and the aqueous medium are evaporated or removed while supplying the aqueous medium, saturated vapor of the aqueous medium, saturated vapor of a water-soluble solvent, or water-soluble gas to maintain the ratio of solid-liquid constant.
    Type: Grant
    Filed: January 27, 1995
    Date of Patent: December 19, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tatsuya Nakamura, Ichiro Ohsaki, Takayuki Nagatsuka, Makoto Kanbayashi, Tatsuhiko Chiba
  • Patent number: 5437949
    Abstract: A color toner for developing an electrostatic image contains a binder resin and a colorant. The color toner has a weight average particle diameter of from 3 .mu.m to 7 .mu.m. The color toner contains from 10% to 70% by number of color toner particles with a particle diameter of 4.00 .mu.m or smaller, not less than 40% by number of color toner particles with a particle diameter of 5.04 .mu.m or smaller, from 2% to 20% by volume of color toner particles with a particle diameter of 8.00 .mu.m or larger, and not more than 6% by volume of color toner particles with a particle diameter of 10.08 .mu.m or larger. The color toner has such a coloring power that an image having been fixed on a transfer medium has an image density (D.sub.0.5) of from 1.0 to 1.8 when an unfixed color toner on the transfer medium is in a quantity (M/S) of 0.50 mg/cm.sup.2.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: August 1, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Tsuyoshi Takiguchi, Wakashi Iida
  • Patent number: 5418102
    Abstract: A developer for developing an electrostatic image has a toner containing a binder resin and a colorant. The binder resin is comprised of an AB-type block copolymer having segment-A and segment-B.The segment-A has a copolymer structure comprised of a styrene monomer and at least one monomer selected from the group consisting of an acrylic monomer, a methacrylic monomer and a diene monomer, and the segment-B has a copolymer structure comprised of a styrene monomer and at least one monomer selected from the group consisting of an acrylic monomer, a methacrylic monomer and a diene monomer, provided that the segment-A and segment-B have copolymer structures different from each other.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: May 23, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takaaki Kotaki, Yoshihiko Hyosu, Ryoichi Fujita, Makoto Kanbayashi, Minoru Shimojo
  • Patent number: 5407776
    Abstract: A toner for developing an electrostatic image has toner particles.The toner particles are prepared by suspension polymerization and contain at least two components comprised of a high softening point resin-A and a low softening point material-B.The toner particles each have a structure separated into a phase-A mainly composed of the resin-A and a phase-B mainly composed of the material-B. The phase-B is absent in the vicinity of the toner particle surface, ranging from its surface to a depth 0.15 time a toner particle diameter.The toner particles contain an organic solvent, a polymerizable monomer or a mixture thereof in a quantity of not more than 1,000 ppm.
    Type: Grant
    Filed: August 25, 1994
    Date of Patent: April 18, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Takayuki Nagatsuka, Takashige Kasuya, Tatsuya Nakamura, Tatsuhiko Chiba
  • Patent number: 5354639
    Abstract: A color toner for developing electrostatic images is formed of color toner particles each including a binder resin, a polyalkylene, and a colorant. The color toner particles are formed by suspension polymerization. The polyalkylene is characterized by having a crystallinity of 10-50% and a melting enthalpy (as measured by a differential scanning calorimeter) of at most 35 cal/g. The color toner is characterized by an improved fixability without causing offset especially at a relatively low temperature and suitable for providing a transparency film for an overhead projection.
    Type: Grant
    Filed: August 28, 1992
    Date of Patent: October 11, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashige Kasuya, Takayuki Nagatsuka, Tatsuya Nakamura, Makoto Kanbayashi, Tatsuhiko Chiba
  • Patent number: 5354640
    Abstract: A toner for developing an electrostatic image has toner particles. The toner particles are prepared by suspension polymerization and contain at least two components comprised of a high softening point resin-A and a low softening point material-B. The toner particles each have a structure separated into a phase-A mainly composed of the resin-A and a phase-B mainly composed of the material-B. The phase-B is absent in the vicinity of the toner particle surface, ranging from its surface to a depth 0.15 time a toner particle diameter. The toner particles contain an organic solvent, a polymerizable monomer or a mixture thereof in a quantity of not more than 1,000 ppm.
    Type: Grant
    Filed: September 21, 1992
    Date of Patent: October 11, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Takayuki Nagatsuka, Takashige Kasuya, Tatsuya Nakamura, Tatsuhiko Chiba
  • Patent number: 5300386
    Abstract: A developer for developing an electrostatic image is disclosed which has a toner including toner particles each containing a polymer, a copolymer or a mixture thereof and from 5 to 30% by weight of a low softening point material, and each having a plurality of concavities on its surface; the toner particles being prepared by suspension polymerization. Also, an image forming method and a heat fixing method using the developer are disclosed.
    Type: Grant
    Filed: March 20, 1992
    Date of Patent: April 5, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Takayuki Nagatsuka, Takashige Kasuya, Tatsuya Nakamura, Tatsuhiko Chiba
  • Patent number: 5281504
    Abstract: A laminate film suitable for providing a transparency for an OHP (overhead projector) is formed by disposing an absorbing layer on a substrate. The absorbing layer functions to allow addition of a wax component to a toner so as to improve the color mixing characteristic and anti-offset characteristic of the toner without causing a wax exudation trace which is liable to occur in a fixed toner image if the absorbing layer is not provided.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: January 25, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Takeshi Menjo, Takayuki Nagatsuka, Takashige Kasuya, Tatsuya Nakamura, Tatsuhiko Chiba, Kohji Inaba
  • Patent number: 5120631
    Abstract: A color toner, comprises non-magnetic resin particles containing a coloring agent and two types of inorganic oxide particles, wherein;particles of coloring agent have an average particle diameter D of 300 m.mu..ltoreq.D.ltoreq.800 m.mu. as determined by measurement of scattered-light intensity; coloring agent particles with a particle diameter of from (D-120) m.mu. to (D+120) m.mu. account for not less than 90% of the whole; coloring agent particles with a particle diameter of 169 m.mu. or less account for not more than 1.0%; and coloring agent particles with a particle diameter of 949 m.mu. or more account for not more than 0.5%;said color toner has a volume average diameter of from 6 to 10 .mu.m; colored resin particles with a particle diameter of 5 .mu.m or less are contained in a proportion of from 15 to 40% by number; colored resin particles with a particle diameter of from 12.7 to 16.0 .mu.m are contained in an amount of from 0.1 to 5.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: June 9, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Kenji Okado, Takayuki Nagatsuka, Yoshinobu Baba
  • Patent number: 4904558
    Abstract: An image forming method that includes the steps of providing a developer comprising at least colored resin particles, a fluidity improver having a specific chargeability and magnetic particles wherein the colored resin particles have a volume-average particle size of 4-10 microns and a specific volume-basis particle size distribution; supplying the developer to a surface of a developer-carrying member disposed opposite to a latent image-bearing member having thereon an electrostatic latent image; carrying the developer on the surface of the developer-carrying member; and developing the electrostatic latent image on the latent image-bearing member with the developer in a developing zone where the latent image-bearing member is disposed opposite to the developer-carrying member to form a toner image; wherein an alternating electric field comprising an AC component and a DC component is imparted to the developing zone under specific conditions.
    Type: Grant
    Filed: March 3, 1989
    Date of Patent: February 27, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takayuki Nagatsuka, Kenji Okado, Makoto Kanbayashi