Ricoh Company, Ltd.

Atsushi Sanpe

Osamu Kizaki

Kazuhisa Sudo

Naomi Misago

Hirohisa Otsuka

An image forming apparatus including a blade for removing a developer left on a photoconductive drum. In addition, a low density pattern is formed on at least a part of the photoconductive drum based on a duration the photoconductive drum is driven.

Image forming apparatus

A contact time with an image carrier and a cleaning blade is added up, and a toner image pattern is formed according to such an added up value. Accordingly, the quantity of toner as a lubricant sticking based on a toner image pattern becomes a most suitable quantity. As the added up value increases when it is described concretely, an area of the toner image pattern is made small, and accordingly a quantity of adhesion of toner is reduced. Accordingly, when a frictional resistance between an image carrier and a cleaning blade becomes low, or when an image carrier deteriorates, a quantity of supply of toner is controlled to be a proper amount

Image forming apparatus with cleaning blade and enhanced lubrication

An electrostatic image forming apparatus has high cleaning efficiency using the electrostatic fur brush method. A photosensitive body having a photoconductive characteristic is charged uniformly. An electrostatic latent image is formed on the surface of the charged photosensitive body by radiating light rays on the area to be developed. The latent image is developed by the dry-type developing method by use of toner charged with same polarity as that of the photosensitive body's surface. The obtained visible image is transferred electrostatically onto the transfer paper. A non-electrically-insulative fur brush 16 removes the remaining toner 20 from the surface of the photosensitive body 14 and an electric potential gradient generator 17 generates an electric potential gradient through the fur brush which transfers the remaining toner 20 to the fur brush 16 from the surface of the photosensitive body 14. The toner to be employed has a substantially uniform particle diameter.

Efficiently removable developing toner in an electrostatic image forming

At least a photosensitive drum 2 and charge roller 9 are attached to a unit 8 so that the photosensitive drum 2 and charge roller 9 can be freely attached to and detached from an apparatus body 1 in unison with the unit case 8, and the charge roller 9 can be freely brought into and out of contact with the surface of the photosensitive drum 2. The apparatus body 1 is provided with pressure cams 5a and 5b adapted to cause the charge roller 9 to be brought into and out of contact with the surface of the photosensitive drum 2.

Image formation apparatus

In an image forming apparatus, an exposing device electrostatically forms a latent image on an image carrier while a developing device develops the latent image with toner to thereby form a corresponding toner image. An image transferring device transfers the toner image to a sheet in contact with the image carrier. A pretransfer lamp discharges the image carrier before the transfer of the toner image to the sheet. A bias applying device applies a bias voltage at the time of the image transfer. A cleaning device removes the toner remaining on the image carrier after the image transfer. A toner conveying device conveys the toner removed by the cleaning device to the developing device. The bias applying device applies the bias voltage only when the sheet exists between the image carrier and the transferring device. The apparatus prevents toner particles charged to the polarity opposite to the expected polarity during an interval between consecutive sheets from being returned to the developing device via the cleaning device, and in addition allows such toner particles to be effectively reused.

Image forming apparatus having a toner recycling mechanism

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 for an electrophotographic apparatus for removing toner particles which remain on a photoconductive element after image transfer. A cleaning blade is movable into contact with the photoconductive element for removing toner particles. A scraping member is held in contact with the cleaning blade by a predetermined pressure to scrape the toner particles off the cleaning blade. When the cleaning blade is moved toward the photoconductive element, an urging member or a resilient member urges the scraping member away from the cleaning blade. The cleaning blade is, therefore, prevented from exerting a load on the scraping member while the cleaning blade cleans the photoconductive element.

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Yokohama, Japan

Atsushi Sanpe