Patents by Inventor Masako Chiba

Masako Chiba 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).

  • Image forming apparatus and charging device thereof
    Patent number: 5881344
    Abstract: An electrophotographic image forming apparatus using a charge roller for uniformly charging the surface of a photoconductive element, or image carrier, during image formation, and a charging device having the charge roller. The charging efficiency is enhanced, and a uniform charge distribution is set up by the application of a DC voltage only. This suppresses the increase in the cost of an apparatus, the increase in power source cost, and the generation of a great amount of ozone. As a result, a charging member and a photoconductive element are prevented from being deteriorated while environmental pollution is eliminated.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: March 9, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Junji Kurokawa, Kazuo Nojima, Masako Chiba, Toshio Nakahara
  • Charge roller for an image forming apparatus
    Patent number: 5786091
    Abstract: In a charging device included in an image forming apparatus for charging an image carrier uniformly, a charge roller has an elastic layer and a surface layer. The elastic layer is made of a substance having a medium electric resistance and having no conductive particles dispersed therein. The surface layer is made of a non-adhering substance having a greater non-adhering property than the substance constituting the elastic layer.
    Type: Grant
    Filed: September 25, 1995
    Date of Patent: July 28, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Junji Kurokawa, Kazuo Nojima, Masako Chiba, Toshio Nakahara
  • Image forming apparatus which maintains a temperature of a charge roller
    Patent number: 5689770
    Abstract: An electrophotographic image forming apparatus using a charge roller for uniformly charging the surface of a photoconductive element, or image carrier, during image formation, and a charging device having the charge roller. The charging efficiency is enhanced, and a uniform charge distribution is set up by the application of a DC voltage only. This suppresses the increase in the cost of an apparatus, the increase in power source cost, and the generation of a great amount of ozone. As a result, a charging member and a photoconductive element are prevented from being deteriorated while environmental pollution is eliminated.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: November 18, 1997
    Assignee: Ricoh Company, Ltd.
    Inventors: Junji Kurokawa, Kazuo Nojima, Masako Chiba, Toshio Nakahara
  • Image forming apparatus and charging device thereof
    Patent number: 5479243
    Abstract: An electrophotographic image forming apparatus using a charge roller for uniformly charging the surface of a photoconductive element, or image carrier, during image formation, and a charging device having the charge roller. The charging efficiency is enhanced, and a uniform charge distribution is set up by the application of a DC voltage only. This suppresses the increase in the cost of an apparatus, the increase in power source cost, and the generation of a great amount of ozone. As a result, a charging member and a photoconductive element are prevented from being deteriorated while environmental pollution is eliminated.
    Type: Grant
    Filed: March 21, 1994
    Date of Patent: December 26, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Junji Kurokawa, Kazuo Nojima, Masako Chiba, Toshio Nakahara