Patents Represented by Law Firm Fisfher,Spivak, McClelland & Maier
  • Patent number: 4205912
    Abstract: An electrophotographic apparatus includes a photoconductive drum capable of rotating at least two rotations during a series of copying processes, a first charging device for charging the surface of the drum in a negative polarity, a first exposing device, a development device having a magnetic brush unit, and a second charging device for transferring image. A second exposing device is provided to expose the entire surface of the photoconductive drum together with the residual toner after the image transfer process during the second rotation of the photoconductive drum. A third charging device is provided to supply positive charges to the surface of the drum and the residual toner after the second exposure. The residual toner is removed from the photoconductive drum by the above described magnetic brush unit charged in the same negative polarity with that of the first charging device and the image transfer device.
    Type: Grant
    Filed: November 8, 1976
    Date of Patent: June 3, 1980
    Assignee: Tokyo Shibaura Electric Company Limited
    Inventors: Yasuhiro Yamaguchi, Mamoru Baba, Tetsuo Inoue, Mitsuaki Koyama