Patents by Inventor Shoichi Sakata

Shoichi Sakata 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: 6829448
    Abstract: A method and apparatus for image forming includes a hybrid developing apparatus that supplies surly charged toner to a developing roll. The apparatus includes a developing roll that is electrically conductive at least on its surface. The image forming apparatus and the method have a constitution capable of applying an alternating current bias having a duty ratio in the range of 10 to 50% and a direct current bias superposed thereon. The developing roll is directly confronted with a latent image bearing body through an insulative toner thin layer at the nearest region of the developing roll and the latent image bearing body. An independent bias is applied to each of the developing roll and the magnetic roll, and the toner is refreshed by the varying duty ratio of the alternate current bias and the direct current bias after developing.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: December 7, 2004
    Assignee: Kyocera Corporation
    Inventors: Yoshio Ozawa, Yuji Kamiyama, Shoichi Sakata, Toshinori Nishimura
  • Publication number: 20040228661
    Abstract: The electrophotographic image formation apparatus of the present invention adopts a developer roller, which is made of aluminum and has an aluminum oxide film of at least 5 &mgr;m in thickness formed on surface thereof. In the image formation apparatus, a gap between the developer roller and a photoreceptor drum 3 is set in a range of 150 to 300 &mgr;m. The image formation method of the present invention regulates a frequency of AC voltage in a non-development state to be higher than that in a development state, when an AC voltage is applied onto the developer roller to cause flight of toner from the developer roller to the photoreceptor, and selectively makes charged toner fly onto the electrostatic latent image for development. The present invention provides the effective development technique to prevent leakage of the applied voltage between the developer roller and the photoreceptor drum.
    Type: Application
    Filed: April 1, 2004
    Publication date: November 18, 2004
    Inventors: Masashi Fujishima, Shoichi Sakata
  • Publication number: 20040022549
    Abstract: In order to provide a compact, rapid and inexpensive image forming apparatus and method of the same having a hybrid developing apparatus wherein developing ghost and selective developing are avoided without complicating a developing apparatus and surly charged toner is supplied to a developing roll while stable quality images are obtained for a long time, an image forming apparatus and a method of the same which is characterized in that a developing roll is electrically conductive at least on its surface and a continuous plane of electrode to which a developing bias is applied in the direction of circumference at developing region by the surface is formed, and that the image forming apparatus and the method have a constitution capable of applying an alternate current bias having a duty ratio within the range from 10 to 50% and a direct current bias superposed thereon wherein the developing roll is directly confronted with a latent image bearing body through an insulative toner thin layer at the nearest region
    Type: Application
    Filed: March 25, 2003
    Publication date: February 5, 2004
    Inventors: Yoshio Ozawa, Yuji Kamiyama, Shoichi Sakata, Toshinori Nishimura
  • Publication number: 20040002015
    Abstract: To avoid developing ghost and selective developing without complicating a developing apparatus and to supply surly charged toner to a developing roll while unevenness of images is not generated to obtain stable images for a long time even when continuous printing, a method for developing in a hybrid developing apparatus is provided, which is characterized in that a data amount of each image, which an image forming apparatus prints and a number of paper sheets passed are detected and that an interval of the action of recovering and exchanging a toner layer on the developing roll to the magnetic roll after printing (between paper sheets) is variably set in accordance with a printing coefficient determined by the data amount and the number of paper sheets passed and further, a method for developing in a color tandem-type image forming apparatus provided with a plurality of the hybrid developing apparatuses for all different colors of toner, which are disposed along the moving direction of a transfer medium of im
    Type: Application
    Filed: March 14, 2003
    Publication date: January 1, 2004
    Inventors: Yoshio Ozawa, Shoichi Sakata, Toshinori Nishimura
  • Publication number: 20030049054
    Abstract: An image forming apparatus of non-contact developing method using two-component developer material which is capable of obtaining a clear image free from fogging, ghost and toner contamination. The image forming apparatus has at least one developing unit which develops an electrostatic latent image on a photosensitive body with a toner thin layer formed on the surface of a developing roll wherein a toner thin layer forming region on the developing roll is smaller than a magnetic brush forming region on the magnetic brush.
    Type: Application
    Filed: June 13, 2002
    Publication date: March 13, 2003
    Inventors: Yoshio Ozawa, Eiji Ochiai, Shoichi Sakata, Toshinori Nishimura, Masayoshi Yamada
  • Patent number: 6512909
    Abstract: When image formation is performed by an apparatus comprising: a magnetic roll for generating a magnetic brush by carrier having toner adhering triboelectrically thereto, a developer roll on the surface of which a thin layer of the toner supplied by the magnetic brush is formed, and a photoreceptor onto which the toner of thin layer jumps selectively in accordance with the latent image thereon; positively chargeable toner of which charge amount is controlled in 5˜20 &mgr;C/g is used, the surface potential of the photoreceptor is set to a range above 0 to 250 V, and the after exposure potential which is the potential right after the photoreceptor is exposed is in a range of 0˜ to 100 V.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: January 28, 2003
    Assignee: Kyocera Corporation
    Inventors: Yoshio Ozawa, Eiji Ochiai, Shoichi Sakata
  • Publication number: 20020018672
    Abstract: When image formation is performed by an apparatus comprising: a magnetic roll for generating a magnetic brush by carrier having toner adhering triboelectrically thereto, a developer roll on the surface of which a thin layer of the toner supplied by the magnetic brush is formed, and a photoreceptor onto which the toner of thin layer jumps selectively in accordance with the latent image thereon; positively chargeable toner of which charge amount is controlled in 5˜20 &mgr;C/g is used, the surface potential of the photoreceptor is set to a range above 0 to 250 V, and the after exposure potential which is the potential right after the photoreceptor is exposed is in a range of 0˜ to 100 V.
    Type: Application
    Filed: July 31, 2001
    Publication date: February 14, 2002
    Inventors: Yoshio Ozawa, Eiji Ochiai, Shoichi Sakata