Mita Industrial Co., Ltd.

Tomohiro Tsutano

Kazuhiro Mizude

Hideki Ishida

Hisahiro Kato

Nariaki Tanaka

Masahiko Maeda

Takashi Terada

Mitsuji Tsujita

Masao Uyama

Takuji Terada

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.

Image forming apparatus having controller adjusting current to main

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.

Image forming apparatus

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.

High speed image forming apparatus

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.

Image forming apparatus provided with pre-transfer charger

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. The discharge wire as the frames are separated moves integrally with the shield upper case and is thus exposed for ease of cleaning and other maintenance. The bipartite shield construction accordingly ensures that the accuracy of the relative positions of the parts forming the terminal portion of the sheet conveyance path is not disturbed when the frames are separated for maintenance access.

Growing community of inventors

Osaka, Japan

Tomohiro Tsutano