Patents by Inventor Kazuhiko Yanagida

Kazuhiko Yanagida 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: 6416919
    Abstract: The present invention discloses a carrier, which comprises a core and a resin coating layer formed thereon containing electroconductive powder, wherein, when the magnetic brush is formed only of the core, the dynamic electrical resistance of the core forming the magnetic brush under an electric field of 104 V/cm is 1 &OHgr;·cm or less and the electrical resistance of the resin coating layer is from 10 to 1×108 &OHgr;·cm, a developer using the carrier, and an image-forming method using the developer. Owing to the present invention, a superior solid image, which is free of brush marks and carrier beads carry over, can be obtained.
    Type: Grant
    Filed: October 2, 2000
    Date of Patent: July 9, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kazuhiko Yanagida, Suk Kim, Shigeru Inaba, Taku Fukuhara, Yasuhiro Oda
  • Patent number: 6391506
    Abstract: The present invention discloses a carrier, which comprises a core and a resin coating layer formed thereon containing electroconductive powder, wherein, when the magnetic brush is formed only of the core, the dynamic electrical resistance of the core forming the magnetic brush under an electric field of 104 V/cm is 1 &OHgr;·cm or less and the electrical resistance of the resin coating layer is from 10 to 1×108 &OHgr;·cm, a developer using the carrier, and an image-forming method using the developer. Owing to the present invention, a superior solid image, which is free of brush marks and carrier beads carry over, can be obtained.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: May 21, 2002
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kazuhiko Yanagida, Suk Kim, Shigeru Inaba, Taku Fukuhara, Yasuhiro Oda
  • Patent number: 6124066
    Abstract: A carrier for electrophotography having a resin coating layer containing a conductive powder having an aspect ratio of not less than 3 on the core material, in which the dynamic electric resistance of the core material in a magnetic brush state under an electric field of 10.sup.4 V/cm is not higher than 1 .OMEGA..cm, and the electric resistance of the resin coating layer is within a range of from 10 to 1.times.10.sup.8 .OMEGA..cm, and a developer for an electrostatic latent image using the carrier. An image forming method on which the developing process includes using the above-mentioned developer for an electrostatic latent image, whose development curve, expressed by a contrast potential and the developing toner quantity, has a saturation area, and applying the developing bias to the developer carrying member so that the developing toner quantity shows the saturation characteristic.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: September 26, 2000
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Suk Kim, Yasuo Yamamoto, Kazuhiko Yanagida
  • Patent number: 5932387
    Abstract: The present invention provides a charged member which has no reduction in the amount of electrostatic charge at high temperature and high humidity and no extreme increase in the amount of electrostatic charge at low temperature and low humidity, improves the adhesion force between a charged member and a coating layer, prevents deterioration of developer through peeling of the coating layer. It provides excellent durability without deterioration of toner through adhering of a toner to the carrier. More particularly, a carrier for electrophotography and a sleeve for electrostatic development which use as a coating material a high-molecular compound containing as an essential component the first monomer represented by the following general formula (1) and/or (2), the second monomer represented by the following general formula (3) and/or (4) and a coupling agent containing a vinyl group are provided.
    Type: Grant
    Filed: August 6, 1997
    Date of Patent: August 3, 1999
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yasuo Yamamoto, Takeshi Agata, Masato Mikami, Kazuhiko Yanagida, Suk Kim
  • Patent number: 5783345
    Abstract: An image forming method wherein a developer layer formed by a layer forming material and supported on a developer supporting body is used to develop an electrostatic latent image on an electrostatic latent image supporting body, thereby forming an image. In the method, the direction of rotation of the developer supporting body is the same as that of the electrostatic latent image supporting body, the ratio of peripheral speed of the developer supporting body to the electrostatic latent image supporting body ranges from 0.7 to 1.8, the developer is composed of a carrier and a toner, and the toner contains a conductive inorganic fine powder. The method is useful for making an amount of static electrification of the toner suitable and stabilizing the same.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: July 21, 1998
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Susumu Yoshino, Suk Kim, Takashi Imai, Kazuhiko Yanagida, Koichi Takashima
  • Patent number: 5672455
    Abstract: A carrier for an electrostatic latent-image developer, comprising a core material having thereon a coating layer comprising a resin and fine electroconductive particles, the resin having a work function of 4.5 eV or lower. An electrostatic latent-image developer comprising the carrier and a toner and an image forming process are also disclosed. The carrier is capable of maintaining a high build-up speed of electrification and a proper electrification level even when a charge control agent is omitted or used in a slight amount or when the addition amount of an additive such as silica and titanium oxide is reduced so as to prevent carrier fouling with a charge control agent or an external additive and to inhibit a decrease in developer life.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: September 30, 1997
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kazuhiko Yanagida, Susumu Yoshino, Takashi Imai, Koichi Takahashi, Suk Kim
  • Patent number: 5576806
    Abstract: A charging roll fit for use at high speed, having good maintaining property of charging characteristics in long-term use, stable in electric resistance under the environmental conditions, and having no fear of pinhole leak and photoreceptor contamination, which comprises a conductive shaft and a conductive layer formed thereon, wherein said conductive layer contains a layer in which SnO.sub.2-x -coated BaSO.sub.4 particles having an electric resistance of 0.1 to 10 .OMEGA..multidot.cm are dispersed in a resin, and the value of x is 0 to 1.
    Type: Grant
    Filed: August 21, 1995
    Date of Patent: November 19, 1996
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kozo Oka, Kazuhiko Yanagida, Taketoshi Hoshizaki, Kazuhiro Koseki