Patents by Inventor Yoshio Takizawa

Yoshio Takizawa 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: 7162180
    Abstract: The present invention provides an improved elastic material which is free of roller abrasion when used in development rollers and overcomes disadvantages of the conventional silicone rollers of deterioration in the abrasion resistance, an elastic roller employing such elastic materials, and an electrophotographic apparatus and electrostatic recording apparatus incorporating such rollers. The elastic material satisfies a relationship represented by the following equation: log{(Tb·Eb)?1}??0.0011(Hd)2+0.1154(Hd)?5.6 where Tb is the tensile strength (N/mm2), Eb is the tension fracture elongation (%) and Hd is the Asker C hardness (°). Further, the present invention provides a novel developer carrier for use with an imaging apparatus and an imaging apparatus incorporating the developer carrier. The developer carrier includes an electrically conductive elastic layer and is arranged in contact with, or in the proximity of, an imaging body.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: January 9, 2007
    Assignee: Bridgestone Corporation
    Inventors: Yoshio Takizawa, Yuichiro Mori, Shu Inoue, Ryuta Tanaka
  • Patent number: 6067434
    Abstract: A developing roller supports a one-component developer on a surface thereof in the form of a thin layer, and is brought in contact with or in proximity to an image forming body in such a state, to supply the developer on a surface of the image forming body, thereby allowing a visible image to be formed on the surface of the image forming body. The developing roller includes: an elastic layer having an ionically conductivity whose surface is imparted with a resin component having a high resistivity. Thus, if R1 is a resistance of the roller in a stationary state and R2 is a resistance of the roller in a rotational state, a relationship of R1>R2 is established. With this developing roller, it is possible to obtain a high quality image and a high gradient.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: May 23, 2000
    Assignee: Bridgestone Corporation
    Inventors: Koji Takagi, Yoshio Takizawa, Tokuo Okada, Hiroshi Kaneda, Koichi Iwami
  • Patent number: 6058285
    Abstract: A toner-carrying roller such as a developing roller having a surface gloss of 2 or above, with the surface gloss of the black glass standard plate having a reflective index of 1.567 (according to DIN 67 530) being 100. The toner-carrying roller provides high-quality images free of density variation and fogging owing to its surface characteristics specified by the surface gloss. In addition, it keeps its good performance without deterioration in image quality for a long period of use.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: May 2, 2000
    Assignee: Bridgestone Corporation
    Inventors: Yoshio Takizawa, Koji Takagi, Norihiko Kaga
  • Patent number: 5903808
    Abstract: A developing roller is adapted to carry a developer on its surface and come in contact with or close to a photoconductor drum having an electrostatic latent image borne on its surface whereby the developer is supplied to the drum to visualize the latent image. The developing roller includes a highly conductive shaft and an elastic layer with conductivity formed around the shaft. The elastic layer is surface treated so as to have a resin component which contains a urea resin and/or melamine resin. The roller satisfies log(R.sub.2 /R.sub.1).ltoreq.4.5 wherein the untreated roller has a resistance R.sub.1 and the roller with the resin component has a resistance R.sub.2. The developing roller does not contaminate the photoconductor drum and ensures that images of quality are reproduced without a density variation and background fog over a long time.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: May 11, 1999
    Assignee: Bridgestone Corporation
    Inventors: Yoshio Takizawa, Koji Takagi, Takahiro Kawagoe
  • Patent number: 5900334
    Abstract: The present invention provides a hydrogen occluding alloy exhibiting high hydrogen absorption and desorption rates, and excellent initial activation in practical use, and a method of making it. There is provided a hydrogen occluding alloy having a composition comprising, by wt %, 32 to 38% of rare earth elements essentially consisting of La and/or Ce, 0.5 to 3.5% of Al, 0.5 to 10% of Mn, 0.005 to 0.5% of hydrogen, optionally 0.1 to 17% of Co, and the balance being Ni and unavoidable impurities; wherein the alloy has a microstructure characterized in that fine rare earth element hydride is dispersively distributed in a matrix having a CaCu.sub.5 -type crystal structure in a ratio of 0.5 to 20% by area. There are also provided electrodes and batteries containing such alloys, and methods of making and using such electrodes and batteries.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: May 4, 1999
    Assignee: Mitsubishi Materials Corporation
    Inventors: Masahiro Wada, Yoshio Takizawa
  • Patent number: 5878313
    Abstract: A developing roller (1) includes a highly conductive shaft (2) and a conductive elastic layer (3). When the developing roller carring a one-component developer thereon comes in contact with or in proximity to an image forming body, the developer is supplied from the roller to a surface of the image forming body, thereby forming a visible image on the image forming body surface. The elastic layer (3) has applied to its surface a resin component having an elongation at rupture of less than 10% as measured according to JIS K7113. The developing roller ensures that images of high quality are reproduced without a drop of image density over a long period of time.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: March 2, 1999
    Assignee: Bridgestone Corporation
    Inventors: Koji Takagi, Yoshio Takizawa, Eiji Sawa
  • Patent number: 5697027
    Abstract: A developing roller (1) having a highly conductive shaft (2), an elastic layer (3) having conductivity around the shaft, and a conductive layer (4) on the elastic layer containing carbon black having an oil absorption of 30-80 ml/100 g and a specific surface area of 30-150 m.sup.2 /g. The developing roller carries a developer on its surface and comes in contact with or close to a photoconductor drum having an electrostatic latent image borne on its surface whereby the developer is supplied to the photoconductor drum to visualize the latent image. The developing roller has a low hardness, ensures intimate contact with the photoconductor drum, and is improved in electric conduction stability and anti-staining so that acceptable images can be consistently produced over a long term.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: December 9, 1997
    Assignee: Bridgestone Corporation
    Inventors: Koji Takagi, Yoshio Takizawa, Takahiro Kawagoe
  • Patent number: 5666626
    Abstract: A developing roller (1) having a thin layer of a developer (4) carried thereon and a drum (3) bearing an electrostatic latent image on its surface are rotated in close relationship, thereby feeding the developer (4) to the surface of the drum (3) for visualizing the electrostatic latent image thereon. The ionization potential of the developing roller (1) surface is adjusted to be below the ionization potential of the developer (4) surface when the developer is charged negative and above the ionization potential of the developer (4) surface when the developer is charged positive. The developer has an ionization potential of 4.5-5.5 eV. When using negatively charged developer, the development roller should preferably contain a lubricant or non-ionic surfactant and should preferably be made of a polyurethane containing a polyisocyanate so as to obtain the desired ionization potential.
    Type: Grant
    Filed: March 5, 1996
    Date of Patent: September 9, 1997
    Assignee: Bridgestone Corporation
    Inventors: Yoshio Takizawa, Koji Takagi, Hiroshi Kaneda, Takahiro Kawagoe
  • Patent number: 5634989
    Abstract: A corrosion-resistant amorphous alloy containing Ta in an amount of from 10 to 40 atomic % and Mo, Cr, W, P, B and/or Si is disclosed.This alloy can be prepared by rapidly cooling and solidifying molten alloy, shows a satisfactory corrosion resistance in high-temperature concentrated phosphoric acid, and is adapted to be used as a plant structural material or a separator for a fuel cell.
    Type: Grant
    Filed: July 15, 1992
    Date of Patent: June 3, 1997
    Assignees: Mitsubishi Materials Corporation, Koji Hashimoto
    Inventors: Koji Hashimoto, Akira Mitsuhashi, Katsuhiko Asami, Asahi Kawashima, Yoshio Takizawa
  • Patent number: 5602712
    Abstract: An object, typically photoconductor drum is electrically charged by placing a contact charger member in abutment with the object to be charged and applying voltage between the contact charger member and the object. Charging is effected by properly controlling the capacitance of the contact charger member, the capacitance of the object, and the applied voltage. A sufficient charged potential is achieved through the application of a relatively low voltage, while preventing ozone generation.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: February 11, 1997
    Assignee: Bridgestone Corporation
    Inventors: Hideharu Daifuku, Yoshitomo Masuda, Kinya Suzuki, Hiroshi Harashima, Hiroshi Kaneda, Yoshio Takizawa, Takahiro Kawagoe
  • Patent number: 5565968
    Abstract: A developing roller comprising a conductive layer formed around a shaft carries a non-magnetic one-component developer on its outer surface to form a thin film of the developer and contacts a photoconductor drum having an electrostatic latent image borne on its surface whereby the latent image is developed to form a toner image. In one embodiment, the surface of the conductive layer has a DIN 4776 core roughness depth Rk of 0.5-3.5 .mu.m in a circumferential direction of the roller, and the ratio of circumferential Rk to axial Rk is greater than 1.0. In another embodiment, the surface of the conductive layer is provided with microscopic ridges and recesses which are alternately disposed in a rotational direction to define wavy streaks having a longitudinal direction substantially aligned with an axial direction of the roller.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: October 15, 1996
    Assignee: Bridgestone Corporation
    Inventors: Eiji Sawa, Ryuta Tanaka, Yuichiro Mori, Tokuo Okada, Yoshio Takizawa, Koji Takagi, Takahiro Kawagoe
  • Patent number: 5529642
    Abstract: A nickel-based alloy which is excellent not only in anti-corrosion properties but also in workability is disclosed. The alloy contains 15 to 35 weight % of chromium; 6 to 24 weight % of molybdenum; wherein the sum of chromium plus molybdenum is no greater than 43 weight %; 1.1 to 8 weight % of tantalum; and balance nickel and unavoidable impurities. The alloy may optionally include no greater than 0.1 weight % of nitrogen; no greater than 0.3 weight % of magnesium, no greater than 3 weight % of manganese, no greater than 0.3 weight % of silicon, no greater than 0.1 weight % of carbon, no greater than 6 weight % of iron, no greater than 0.1 weight % of zirconium, no greater than 0.01 weight % of calcium, no greater than 1 weight % of niobium, no greater than 4 weight % of tungsten, no greater than 4 weight % of copper, no greater than 0.8 weight % of titanium, no greater than 0.8 weight % of aluminum, no greater than 5 weight % of cobalt, no greater than 0.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: June 25, 1996
    Assignee: Mitsubishi Materials Corporation
    Inventors: Katsuo Sugahara, Hideo Kitamura, Saburo Wakita, Koji Toyokura, Yoshio Takizawa, Tsutomu Takahashi
  • Patent number: 5475473
    Abstract: An electric charging member and electric charging apparatus are described, including the surface of the charging member being formed of a resin layer including a nylon copolymer containing at least 15% by weight of nylon 12 or a urethane-modified acrylic resin containing 5-80% by weight of an acrylic resin component.
    Type: Grant
    Filed: September 21, 1994
    Date of Patent: December 12, 1995
    Assignee: Bridgestone Corporation
    Inventors: Yoshitomo Masuda, Hajime Tamura, Takahiro Kawagoe, Yoshio Takizawa, Gaku Yakushiji, Kazuya Murata, Shohei Morikawa
  • Patent number: 5434653
    Abstract: A developing roller includes a metal shaft and a conductive resilient sleeve surrounding the shaft and made of a urethane elastomer containing carbon black with at least pH 5. The developing roller is mounted in an electrophotographic apparatus in combination with a latent image-bearing photoreceptor wherein development is carried out using a non-magnetic single-component toner.
    Type: Grant
    Filed: March 29, 1994
    Date of Patent: July 18, 1995
    Assignee: Bridgestone Corporation
    Inventors: Yoshio Takizawa, Koji Takagi, Hiroshi Harashima, Hiroshi Kaneda, Hideyuki Niwa, Taro Miyamoto, Gaku Yakushiji, Takahiro Kawagoe
  • Patent number: 5320921
    Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor comprises a conductive layer and provided thereon, a photoreceptor layer comprising a carrier generation layer containing 100 parts by weight of a polycyclic quinone compound and 0.
    Type: Grant
    Filed: September 3, 1992
    Date of Patent: June 14, 1994
    Assignee: Konica Corporation
    Inventors: Takeo Oshiba, Yoshio Takizawa
  • Patent number: 5270140
    Abstract: An electrophotographic photoreceptors containing a bisstyryl compound represented by the following formula I is disclosed. ##STR1## R.sup.0 and/or R.sup.00 represent methyl group, and the rest of Rs represent hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and Ar.sup.1 and Ar.sup.2 represent each an aromatic group.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: December 14, 1993
    Assignee: Konica Corporation
    Inventors: Naoto Abew, Naohiro Hirose, Hirofumi Hayata, Syozo Mitsui, Shinichi Suzuki, Osamu Sasaki, Yoshio Takizawa, Takeo Oshiba
  • Patent number: 5013625
    Abstract: A photoreceptor that has at least a subbing layer and a light-sensitive layer formed on an electro-conductive supports is disclosed. The improvement is that said subbing layer is formed of a copolymer comprising ethylene, vinyl acetate and an unsaturated carboxylic acid and/or vinyl alcohol.
    Type: Grant
    Filed: February 12, 1990
    Date of Patent: May 7, 1991
    Assignee: Konica Corporation
    Inventors: Yoshio Takizawa, Kunio Sigeta, Shigeki Takeuchi, Hiroshi Yoshioka, Yoshihide Fujimaki
  • Patent number: 4940644
    Abstract: This invention relates to a toner for development of electrostatic images to be used for development of electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, etc., and an image forming method by use thereof.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: July 10, 1990
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Akitoshi Matsubara, Satoru Ikeuchi, Kunio Akimoto, Yoshio Takizawa
  • Patent number: 4935327
    Abstract: A toner for developing an electrostatic image is disclosed, which is not likely cause fogs, toner flying, and solid-black non-uniformity when used for a large number of cpying cycles in a high temperature, high humidity. The toner comprises a polyester resin containing a trivalent or higher monomer as a polymerized component and an antioxidant. As the antioxidant, a compound having a hidered phenolic group is preferably used as the antioxidant.
    Type: Grant
    Filed: December 7, 1988
    Date of Patent: June 19, 1990
    Assignee: Konica Corporation
    Inventors: Yoshio Takizawa, Jiro Takahashi, Akitoshi Matsubara, Satoru Ikeuchi
  • Patent number: 4931375
    Abstract: Disclosed is a toner powder for developing latent electrostatic images comprising as a binder for pigment material a block or graft copolymer composed of a crystalline polyester and an amorphous vinyl polymer. The amorphous vinyl polymer has at least two peaks in its molecular weight distribution curve. One is between 100,000 and 1,000,000 and another is between 2000 and 20,000.
    Type: Grant
    Filed: May 19, 1989
    Date of Patent: June 5, 1990
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Kunio Akimoto, Satoru Ikeuchi, Yoshio Takizawa