Patents by Inventor Kohji Inaba

Kohji Inaba 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: 6183927
    Abstract: An electrophotographic toner is formed of toner particles each comprising at least a binder resin, a colorant and a release agent, and a low-crystalline aromatic metal compound present at surfaces of the toner particles. The toner has an average circularity of at least 0.955, and the low-crystalline aromatic metal compound has an X-ray diffraction characteristic free from peaks exhibiting a measurement intensity of at least 10000 cps and a half-value half-width of at most 0.3 deg. in a range of measurement angles 2&thgr; of 6 to 40 deg. Because of the low crystallinity, the aromatic metal compound is uniformly applied onto the toner particle surfaces to stabilize the chargeability and transferability of the toner.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: February 6, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Michihisa Magome, Hiroaki Kawakami, Tatsuya Nakamura, Tatsuhiko Chiba, Kohji Inaba, Yuji Moriki, Shinya Yachi
  • Patent number: 5827632
    Abstract: A toner for developing electrostatic images includes (a) toner particles having a weight-average particle size of 1-9 .mu.m, (b) hydrophobized inorganic fine powder having an average particle size of 10-90 nm and (c) hydrophobized silicon compound fine powder. The hydrophobized silicon compound fine powder has an average particle size of 30-120 nm, and a particle size distribution such that it contains 15-45% by number of particles having sizes of 5-30 nm, 30-70% by number of particles having sizes of 30-60 nm and 5-45% by number of particles having sizes of at least 60 nm. The hydrophobized silicon compound fine powder having a broad particle size distribution including coarse particles functions to prevent the embedding of the hydrophobized inorganic fine powder (functioning as a flowability improver) from being embedded at the toner particle surfaces, whereby the toner is allowed to exhibit stable performances even in a continuous image formation on a large number of sheets.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: October 27, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kohji Inaba, Tatsuya Nakamura, Tatsuhiko Chiba, Takao Ishiyama
  • Patent number: 5750303
    Abstract: A toner for developing an electrostatic image includes toner particles constituted by at least a binder resin, a colorant, a polar resin and a release agent. The polar resin has at least one terminal group which has been modified by a polycarbonate acid having at least three carboxyl groups. The polar resin has an acid value of 3-35 mgKOH/g. The polar resin may preferably be a polyester resin having an acid value of 4-35 mgKOH/g and having a number-average molecular weight (Mn) of 3,000-15,000, a weight-average molecular weight (Mw) of 6,000-50,000, and an Mw/Mn of 1.2-3.0 based on GPC. The polar resin (preferably polyester resin) having modified by a polycarboxylic acid having at least three carboxylic groups to provide a specific acid value is effective in improving resultant toner performances, such as low-temperature fixability, anti-offset characteristic at high temperatures, triboelectric chargeability, and flowability.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: May 12, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kohji Inaba, Kazunori Kato, Kengo Hayase
  • Patent number: 5747209
    Abstract: A toner for developing electrostatic images is formed of toner particles comprising (a) a binder resin, (b) a colorant or magnetic material, (c) an aromatic hydroxycarboxylic acid (A), and (d) a metal compound of the aromatic hydroxycarboxylic acid (A). The aromatic hydroxycarboxylic acid (A) and the metal compound of the aromatic hydroxycarboxylic acid (A) are contained in a weight ratio of 1:99 to 10:90. As a result of co-inclusion of a small amount of the aromatic hydroxycarboxylic acid (A) in addition to the metal compound thereof, the resultant toner is provided with a quick chargeability in a low humidity environment and an improved level of triboelectric charge in a high humidity environment, presumably because of the stabilization effect of the small amount of the aromatic hydroxycarboxylic acid (A) on the metal compound thereof.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: May 5, 1998
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsuyoshi Takiguchi, Kenji Okado, Masaaki Taya, Ryoichi Fujita, Makoto Kanbayashi, Kohji Inaba, Wakashi Iida, Kazunori Kato, Tetsuya Ida, Shinya Yachi
  • Patent number: 5712072
    Abstract: The present invention relates to a toner for developing an electrostatic image, comprising toner particles containing a binding resin composed of a styrene homopolymer or copolymer, a coloring agent, a polar resin, and a specified solid ester wax.
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: January 27, 1998
    Assignee: Canon Kabusbiki Kaisha
    Inventors: Kohji Inaba, Tatsuya Nakamura, Tatsuhiko Chiba, Kengo Hayase
  • Patent number: 5635325
    Abstract: A toner for developing electrostatic images includes: at least a binder resin, a colorant and an ester wax. The ester wax is contained in 3-40 wt. parts per 100 wt. parts of the binder resin. The ester wax includes ester compounds represented by a formula ofR.sub.1 --COO--R.sub.2,wherein R.sub.1 an R.sub.2 independently denote a hydrocarbon group of 15-45 carbon atoms. The ester wax contains 50-95 wt. % thereof of ester compounds having an identical number of total carbon atoms. The toner is especially characterized by low-temperature fixability, wide non-offset temperature range, good color mixing characteristic and transparency.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: June 3, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kohji Inaba, Tatsuya Nakamura, Tatsuhiko Chiba, Takao Ishiyama, Kengo Hayase
  • Patent number: 5582902
    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: November 4, 1993
    Date of Patent: December 10, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Takeshi Menjo, Takayuki Nagatsuka, Takashige Kasuya, Tatsuya Nakamura, Tatsuhiko Chiba, Kohji Inaba
  • Patent number: 5510222
    Abstract: A toner for developing an electrostatic latent image is constituted by a binder resin, a colorant, and an ester compound (a), (b) or (c) shown below: (a) a poly-functional ester having a tertiary carbon or/and a quaternary carbon and obtained from an alcohol compound or carboxylic compound having at least two functional groups, (b) a mono-functional ester having a tertiary carbon or/and a quaternary carbon, or (c) a poly-functional ester of a specific structure having a primary or secondary carbon having at least two functional groups. The ester compound is characterized by a good affinity with the binder resin, a high hydrophobicity and a low crystallinity, thereby providing a toner which shows good low-temperature fixability, anti-offset characteristic, color-mixing characteristic and transparency.
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: April 23, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kohji Inaba, Tatsuya Nakamura, Tatsuhiko Chiba, Takao Ishiyama
  • Patent number: 5480759
    Abstract: An electrophotographic toner showing a good fixability onto recording paper is constituted by at least a binder resin and a colorant, the binder resin comprising a resin component having a polar group, the binder resin having a molecular weight distribution according to gel permeation chromatography including a peak in a molecular weight region of 5.times.10.sup.3 -5.times.10.sup.4. The toner is used to develop an electrostatic image formed on a electrophotographic photosensitive member including at least an electroconductive support, a charge generation layer and a charge transport layer, and the resultant toner image is transferred onto a recording medium without difficulties such as occurrence of cracks on the photosensitive member or inferior transferability by using a photosensitive member having a surface layer containing a transition metal atom at 0.1-10 ppm.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: January 2, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashige Kasuya, Noboru Kashimura, Tatsuya Nakamura, Tatsuhiko Chiba, Kohji Inaba
  • 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: 4552751
    Abstract: The present invention provides multi-layered film preparations which comprise one or more water soluble polymer bases, one or more water insoluble polymer bases, one or more plasticizers and one or more prostaglandins, and optionally contain one or more organic acids, and they are composed of at least two drug release controlling layers and one or more drug storing layers. The multi-layered film preparations of the present invention are characterized by that the prostaglandin(s) containing therein exhibit the desired long-lasting release patterns at the concentration required for therapeutic purpose.
    Type: Grant
    Filed: October 19, 1981
    Date of Patent: November 12, 1985
    Assignee: Ono Pharmaceutical Co., Ltd.
    Inventors: Kohji Inaba, Seiei Sasatani, Tatsushi Koide, Tamio Nanya
  • Patent number: 4483846
    Abstract: The present invention provides new three-layered pharmaceutical film preparations which comprise one drug-storing middle layer composed of one or more (a) polyvinylpyrrolidone, (b) hydroxypropyl cellulose, (c) plasticizers and (d) organic acids, containing prostaglandin analogues, and two release-controlling layers on both sides of the said middle layer, composed of one or more (a) hydroxypropyl cellulose and (b) plasticizers, containing or not containing prostaglandin analogues, and which may release the drug at the desired concentration lastingly for an extended period of time, with great high biological availability, and can make this release "zero-order release", and further have improved the stability of the drug contained therein, and in which the form of the preparation is not retained at the administered site after administration.
    Type: Grant
    Filed: February 7, 1983
    Date of Patent: November 20, 1984
    Assignee: Ono Pharmaceutical Co., Ltd.
    Inventors: Tatsushi Koide, Seiei Sasatani, Kohji Inaba