Carrier Particle Conductivity Or Resistivity Patents (Class 430/122.4)
  • Patent number: 8903270
    Abstract: A developing device including a developer bearing member containing a magnetic field generator having multiple magnetic poles and a developer containing chamber is provided. The developer containing chamber contains a two-component developer comprising magnetic carrier particles having a saturated magnetization of 58 to 70 emu/g in a magnetic field of 1KOe and toner particles, and has a divider to define an upper supply chamber and a lower collection chamber. The supply chamber includes a supply conveyer to supply the two-component developer to the developer bearing member at an upstream side from the developing area. The collection chamber includes a collection conveyer to collect the two-component developer from the developer bearing member at a downstream side from the developing area. The multiple magnetic poles includes three developer bearing poles capable of bearing the developer on its surface.
    Type: Grant
    Filed: March 5, 2012
    Date of Patent: December 2, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Koichi Sakata, Shigenori Yaguchi, Toyoshi Sawada, Hitoshi Iwatsuki, Hiroyuki Kishida
  • Patent number: 8512929
    Abstract: A latent electrostatic image developing carrier including a carrier core material, and a coating layer containing a resin and provided on a surface of the carrier core material, wherein the coating layer includes a particulate material containing at least first fine conductive particles and second fine conductive particles, and wherein the first fine conductive particles and the second fine conductive particles satisfy the relationships expressed by Expressions 1 and 2, 3?D1/D2?15 . . . Expression 1, where D1 denotes a dispersed particle diameter of the first fine conductive particles and D2 denotes a dispersed particle diameter of the second fine conductive particles, and ?7E?R1×R2?8E . . . Expression 2, where R1 denotes a powder specific resistance of the first fine conductive particles and R2 denotes a powder specific resistance of the second fine conductive particles.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: August 20, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Hitoshi Iwatsuki, Kimitoshi Yamaguchi, Minoru Masuda, Yutaka Takahashi, Koichi Sakata, Toyoaki Tano
  • Patent number: 7840152
    Abstract: A transfer residual toner that has not been electrostatically transferred onto a transfer paper P at a transfer nip and remains on a surface of a photosensitive element is temporarily retained by an elastic blade of a toner retaining unit in a mechanical manner before reaching a latent image forming area. When passing through the latent image forming area, the transfer residual toner is returned onto the surface of the photosensitive member at such a timing that writing is not performed by an exposing unit on the surface of the photosensitive element.
    Type: Grant
    Filed: January 2, 2009
    Date of Patent: November 23, 2010
    Assignee: Ricoh Company, Limited
    Inventors: Yasushi Koichi, Koji Suzuki, Shigekazu Enoki, Osamu Ariizumi, Kumiko Hatakeyama
  • Patent number: 7560049
    Abstract: A method of manufacturing a device, comprising printing an aqueous solution or dispersion comprising an electronically functional substance, for example a conducting polymer such as PEDOT-PSS, and a surface tension reducing agent onto predetermined portions of a hydrophobic surface, for example formed by a ferroelectric polymer layer. The conducting polymer can form conductive tracks on either side of the ferroelectric layer to form a memory device.
    Type: Grant
    Filed: December 11, 2006
    Date of Patent: July 14, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Christopher Newsome, Daping Chu
  • Patent number: 7320852
    Abstract: A carrier for use with a toner as a two-component type developer for developing an electrostatic image, comprising spherical magnetic core particles, and a resin layer covering each of said core particles and containing at least two resistance controlling materials having different specific resistances, wherein each of the resistance controlling materials is in the form of particles having a number average particle diameter of no more than 1/10 of a number average particle diameter of the toner.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: January 22, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Akihiro Kotsugai, Kimitoshi Yamaguchi, Naoki Imahashi, Hiroaki Takahashi