Patents by Inventor Tomohiro Tsutano

Tomohiro Tsutano 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: 5552861
    Abstract: An image forming apparatus is provided with a high voltage transformer provided with one common secondary winding for supplying a high voltage power to a main charger and to a transferring charger, a resistor for sensing a shield current of the transferring charger, an error detecting amplifier for controlling a primary side of the high voltage transformer so that the sensed shield current is constant; a constant voltage device connected to a grid of the main charger for constant-voltage controlling the main charger, and a resistor inserted in a current path to the transferring charger for setting a current supplied from the high voltage transformer to the main charger to be greater than a current supplied from the high voltage transformer to the transferring charger.
    Type: Grant
    Filed: December 2, 1994
    Date of Patent: September 3, 1996
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Kazuhiro Mizude, Hisahiro Kato, Hideki Ishida, Tomohiro Tsutano
  • Patent number: 5530525
    Abstract: An image forming apparatus includes a charge removing device for removing the residual charge on a photosensitive film. The light emitted from an optical source of the charge removing device is selected from the range between the wavelengths which correspond to half of the maximum absorbance in a light absorbance characteristic of the photosensitive film. Since carrier generation does not occur by the light emitted by the charge removing device, the charging ability and the charge retaining ability of the photosensitive film are improved, and the image quality is significantly improved.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: June 25, 1996
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Mitsuji Tsujita, Masahiko Maeda, Kazuhiro Mizude, Tomohiro Tsutano, Masao Uyama, Nariaki Tanaka, Takashi Terada, Takuji Terada
  • Patent number: 5499081
    Abstract: An image forming apparatus includes a photosensitive drum driver for rotating a photosensitive drum at either a normal speed or a higher speed, a charger, a charge remover for removing residual charges on the photosensitive drum surface after a toner image is transferred, a starter for instructing a start of image forming operation, and a controller responsive to the starter for controlling the operative parts. Upon the starter being turned on, the controller drives the charger and the charge remover, and permits the photosensitive drum driver to rotate the photosensitive drum at the higher speed, and suspends the image formation, After the photosensitive drum completes the initial one turn, the controller starts the image formation and permits the photosensitive drum driver to rotate the photosensitive drum at the normal speed.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: March 12, 1996
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Kazuhiro Mizude, Hideki Ishida, Hisahiro Kato, Tomohiro Tsutano
  • Patent number: 5481345
    Abstract: An image forming apparatus includes a photosensitive drum rotatable, a developer disposed near the photosensitive drum for developing an electrostatic latent image into a toner image, a transfer disposed on a downstream of the developer for transferring the toner image onto copy paper, and a pre-transfer charger disposed between the developer and the transfer for charging the photosensitive drum at a specified level to assure a smooth transfer of the toner image from the photosensitive drum to the copy paper, the charger including a casing formed with a guide portion for guiding the copy paper to the transfer.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: January 2, 1996
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Hideki Ishida, Kazuhiro Mizude, Hisahiro Kato, Tomohiro Tsutano
  • Patent number: 5479239
    Abstract: For a pre-transfer charging device provided in image processing apparatus for a xerographic image reproducing machine, a bipartite shield is provided, having a shield upper case mounted in an imaging apparatus first frame, and a shield lower case mounted in an imaging apparatus second frame fitted with a guide at least partially defining a sheet conveyance path into an imaging unit of the imaging apparatus. The imaging unit includes a chargeable photoconductor drum and is mounted in the first frame, which is pivotally joined to the second frame. A bottom exterior surface of the shield lower case serves as a guide partially defining a terminal portion of the sheet conveyance path. A discharge wire is fitted in the shield upper case, extending axially within the pre-transfer charging device, and therein is movable integrally with the shield upper case. During maintenance on the imaging apparatus, the first frame is opened off of the second frame.
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: December 26, 1995
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Hideki Ishida, Kazuhiro Mizude, Hisahiro Kato, Tomohiro Tsutano