Ricoh Company, Ltd.

Naomi Misago

Tadashi Hayakawa

Hidetoshi Yano

Sadao Takahashi

Kazuhisa Sudo

Nobuo Kikuchi

Yoshiaki Miyashita

Takeshi Tabuchi

Kentaro Matsumoto

Atsushi Sanpe

Kouichi Yamazaki

Hirohisa Otsuka

Hirohisa Ohtsuka

In an image forming apparatus, a latent image is electrostatically formed on a photoconductive element and then developed by a developing unit. The developing unit is formed with a used toner inlet for receiving used toner. A cleaning unit removes toner remaining on the photoconductive element after image transfer and thereby collects it as the used toner. A conveying device conveys the used toner from the cleaning unit to the used toner inlet of the developing unit. A toner end sensor is disposed in the developing unit and adjoins the used toner inlet. On determining that the amount of toner existing in the developing unit is less than a predetermined amount, the sensor causes fresh toner to be replenished into the unit.

Image forming apparatus using fresh toner and used toner

In an image forming apparatus, a charging member, image transfer member or similar contact member contacts an image carrier implemented as a photoconductive element. Even when a voltage is applied to the contact member in a relatively low temperature environment, the contact member is provided with an adequate charge potential or an image transfer potential.

Image forming apparatus with a contact member contacting an image carrier

An image recording apparatus includes a toner supplying unit for supplying fresh toner to a toner chamber via a toner supplying passage; a toner collecting unit for collecting toner which remains on a photosensitive medium after an image on the photosensitive medium is transferred to a sheet of paper, and for supplying the collected toner to the toner chamber via a toner collecting passage; a toner ratio detecting unit for detecting whether or not a ratio of the collected toner to the fresh toner relating to a quantity of to toner contained in the toner chamber is greater than a maximum allowable ratio; and a toner quantity control for it for allowing the toner supplying unit to supply free toner to the toner chamber when the ratio relating to the quantity of toner contained in the toner chamber is detected to be greater than the maximum allowable ratio.

Image recording apparatus having a toner quantity control unit

An electrophotographic image forming apparatus capable of collecting a toner remaining on a photoconductive element after image transfer. A developing device develops a latent image electrostatically formed on the surface of a photoconductive element. A paper and paper dust, paper fibers and other impurities produced from the paper before, after and during image transfer are caused to electrostatically adhere to a transfer belt included in a contact type transferring device. After the developed image has been transferred to the paper, a cleaning device associated with the photoconductive element removes a toner remaining thereon. The tone so collected by the cleaning device is conveyed to the developing device by a transporting device. Impurities deposited on the transfer belt are not conveyed to the developing device. An arrangement of a bias roller having a transfer bias from a high-tension power source and a contact plate located downstream of the bias roller ensure not only that the impurities remain on the transfer belt but also reduce reverse charging during image transfer with the result that most of the residual toner reaches the drum cleaning device while preserving the original polarity thereof.

Image forming apparatus having a toner collecting mechanism for removing

A cleaning device incorporated in an image forming apparatus for removing a toner remaining on a photoconductive drum by a fur brush and collecting the removed toner by a collecting roller. The cleaning device selectively moves the fur brush into and out of contact with both of the photoconductive drum and collecting roller.

Growing community of inventors

Tokyo, Japan

Naomi Misago