Patents by Inventor Wakashi Iida

Wakashi Iida 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: 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: 5700617
    Abstract: A toner for developing an electrostatic image is formed from toner particles containing a binder resin, a colorant, and a charge-controlling agent. The charge-controlling agent comprises an aromatic oxycarboxylic acid, a metal compound of the aromatic oxycarboxylic acid, and an inorganic compound formed from an inorganic anion and an inorganic cation. The aromatic oxycarboxylic acid, the metal compound of the aromatic carboxylic acid and the inorganic anion are contained in proportions of A (wt. %), B (wt. %) and C (ppm), respectively, satisfying the following conditions: 1/99.ltoreq.A/B.ltoreq.20/80, and 10.sup.2 .ltoreq.C. Because of the inclusion of an inorganic compound providing a sufficient amount of inorganic anion, the charge-controlling agent shows a stable charge-controlling characteristic, and the resultant toner exhibits a stable developing performance and transferability in continuous image formation in various environmental conditions.
    Type: Grant
    Filed: October 8, 1996
    Date of Patent: December 23, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsuyoshi Takiguchi, Kenji Okado, Masaaki Taya, Ryoichi Fujita, Makoto Kanbayashi, Wakashi Iida, Tetsuya Ida
  • Patent number: 5670288
    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..multidot.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: February 12, 1996
    Date of Patent: September 23, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Okado, Toshiyuki Ugai, Ryoichi Fujita, Makoto Kanbayashi, Tsuyoshi Takiguchi, Yasuhiro Ichikawa, Wakashi Iida
  • Patent number: 5635326
    Abstract: A toner for developing an electrostatic image, which comprises a colorant-containing particulate resin and a treated fine powdery material prepared by treating fine powdery titanium oxide with a silane-type organic compound, where the fine powdery titanium oxide is mainly composed of a TiO.sub.2 component and a Ti(OR).sub.m (OH).sub.n component wherein R is a hydrocarbon group, m and n are respectively an integer of from 0 to 4, and m+n is 4.
    Type: Grant
    Filed: February 9, 1995
    Date of Patent: June 3, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Tsuyoshi Takiguchi, Wakashi Iida
  • Patent number: 5607806
    Abstract: A toner for developing electrostatic images includes: toner particles and organically treated alumina powder. The organically treated alumina powder has an X-ray diffraction characteristic showing a maximum X-ray intensity level I.sub.a-max and a minimum X-ray intensity level I.sub.a-min in a 2.theta. range of 20 to 70 degrees providing a ratio I.sub.a-max /I.sub.a-min of below 6. The alumina powder is amorphous or has a low-crystallinity of .gamma.-form, thereby showing a low agglomeratability to function as an effective flowability-improving agent for a toner. The structural water contained in the alumina powder contained favors hydrophobization treatment thereof and functions to suppress a charge-up phenomenon in a low humidity environment after the hydrophobization.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: March 4, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Wakashi Iida
  • Patent number: 5529865
    Abstract: An image forming method includes the steps of:(1) forming a first unfixed image of color toner on one side of a transfer material, wherein the color toner has a weight average particle size of 3 to 7 .mu.m and includes color toner particles having a particle size of 4 .mu.m or less in a range of 10 to 70 by number, color toner particles having a particle size of 5.04 .mu.m or less in a range of 40% by number or more, color toner particles having a particle size of 8 .mu.m or more in a range of 2 to 20% by volume, and color toner particles having a particle size of 10.08 .mu.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: June 25, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Makoto Kanbayashi, Tsuyoshi Takiguchi, Wakashi Iida
  • 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: 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