Ricoh Company, Ltd.

Yasunori Kawaishi

Hideki Kamiyama

Nobuo Kasahara

Mitsuru Takahashi

Takashi Bisaiji

Toshiaki Motohashi

Hideo Yu

Tatsuo Hirono

Makoto Ohsaki

Satoshi Takano

Jun Okamoto

Yoshihiro Sakai

Hiroyuki Fushimi

Katsuya Kawagoe

Itaru Matsuda

Takeyoshi Sekine

Hideya Furuta

Kenichi Mizuma

Yuko Harasawa

Hiroshi Yamasita

Kouta Fujimdri

Nobuyuki Yanagawa

Kazunori Bannai

Shigeru Suzuki

Noriyuki Kimura

Tatsuo Tani

Shin Kayahara

Kazushige Taguchi

Mitsuru Mamizuka

Minoru Sugiyama

Yukihiro Ohno

Leo Munakata

Shinju Nagatsuna

An image forming apparatus and method of using the apparatus including: an image carrier; and an intermediate image transfer unit. The intermediate transfer unit includes: an intermediate image transfer belt which is movable while contacting a surface of the image carrier over a preselected distance; a discharging member for discharging a charge deposited on the intermediate image transfer belt at a nip between the intermediate image transfer belt and the image carrier; a charge depositing member for depositing a transfer charge on the intermediate image transfer belt at a position downstream of the nip in a direction of movement of the intermediate image transfer belt, whereby a toner image formed on the image carrier is transferred to the intermediate image transfer belt itself or a recording medium by an electric field formed at the nip; and the discharging member discharging the charge deposited on the intermediate image transfer belt at the nip so that the discharging member is in contact with a surface of the intermediate image transfer belt opposite to a surface contacting the image carrier with a pressure between 0.05 N/cm,and 2 N/cm,.

Image transferring method and image forming apparatus for transferring toner image from image carrier to recording medium either via or carried on intermediate image transfer belt

The current methods and systems for cleaning residual ultra-fine spherical toner from an image forming surface discloses the application of aspherical toner to a cleaning blade. The aspherical toner is generally larger than the ultra-fine spherical toner which provides a superior image on an image-carrying medium. According to one preferred embodiment of the current invention, the aspherical black toner is placed in a predetermined area outside of a desired image area where the ultra-fine spherical toner in multiple colors is placed. The aspherical toner is transported to the cleaning blade before the multi-color toner reaches the cleaning blade. Since the aspherical toner applied at a contacting edge of the cleaning blade provide an effective seal or trap between the cleaning blade and the image forming surface, the ultra-fine spherical toner is effectively removed from the image forming surface.

Methods and systems for cleaning residual toner from image developing

An image forming apparatus of the type forming a toner image on a photoconductive drum or similar image carrier, transferring it to a paper or similar transfer medium via an intermediate transfer body, e.g., belt, and fixing it on the medium by a fixing device is disclosed. Just after the transfer of a toner image of the last color which is to lie over the other toner images on the intermediate transfer belt, the peripheral speed of the belt is switched to a comparatively low speed matching a fixing and paper transport speed. At this instant, the belt is moved away from the drum. The length of the transfer medium and the distance between a paper transfer position and a fixing position is compared. For a relatively short transfer medium, the peripheral speed of the belt is not switched to the low speed.

Image forming apparatus for fixing a toner image at a first speed or at

A device incorporated in an image forming apparatus for transferring a toner image from a photoconductive element to an intermediate transfer belt and then from the intermediate transfer belt to a sheet or similar recording medium. An electrode member is implemented as a belt drive roller and located at the rear of a portion of the intermediate transfer belt which lies in a position for transferring the toner image from the belt to a sheet. The electrode member has a specific volume resistance of 10.sup.7 .OMEGA.cm to 10.sup.12 .OMEGA.cm.

Image transferring device for an image forming apparatus

The apparatus includes a photoconductive element and a transfer belt, with an electrode or bias applicator located downstream from a nip formed between the photoconductive element and the transfer belt. Upstream from the nip, a roller is provided which can also act as an electrode, or which can be held in an electrically floating state. A bias voltage can be provided to the roller upstream from the nip, with the voltage equal to or less than the voltage applied to the downstream electrode so as form a potential gradient. In addition, the applied voltages can be varied based upon the position of a sheet of paper, or in response to changes in humidity.

Image transferring device and medium separating device for an image

Methods and systems for cleaning residual toner from image-developing

An image forming apparatus includes a photoconductive element and a transfer belt, with an electrode or bias applicator located downstream from a nip formed between the photoconductive element and the transfer belt. Upstream from the nip, a roller is provided which can also act as an electrode, or which can be held in an electrically floating state. A bias voltage can also be provided to the roller upstream from the nip, with the voltage equal to or less than the voltage applied to the downstream electrode. In addition, the applied voltages can be varied based upon the position of a sheet of paper, or in response to changes in humidity.

An image recording apparatus is disclosed which includes an intermediate transfer belt rotatable in a reciprocating motion. Before the belt is rotated back and forth for forming a composite toner image, it is rotated in the opposite direction to the image forming direction. This provides the belt with substantially the same deviation in both the forward movement and the reverse movement. Hence, the apparatus insures desirable images by preventing the individual toner images from being brought out of register due to the deviation of the belt.

Image recording apparatus

A multicolor image forming apparatus having an image transfer structure capable of preventing a transferred image and an image formed on a photoconductive element from being dislocated from each other. A backup roller facing a photoconductive element and a tension roller are movable toward and away from the element at the same time over the same distance. A single cam intervenes between support members supporting the two rollers and moves the rollers by half a rotation thereof.

Multicolor image forming apparatus with tension controlled image

An image forming apparatus which insures stable image transfer at all times with no regard to aging and environment. An electrometer is located in close proximity to and opposite to a transfer region where an image carrier and a transfer medium face each other. A voltage to be applied to an electrode which applies a transfe voltage to the transfer medium is controlled in response to the output of the electrometer such that the electric field in the transfer region remains constant.

Image forming apparatus with transfer medium and electrometer positioned

A copier, laser printer or similar image forming apparatus of the type having an intermediate image transfer body in the form of a belt allows documents to be reproduced in a page-sequential paper discharge mode which discharges paper sheets, or recording media, in order of page. When an automatic two-sided copy mode is selected, the apparatus automatically sets up the page-sequential paper discharge mode. Hence, when two sided black-and-white documents and color documents are reproduced together in the automatic two-sided copy mode, paper sheets are driven out of the apparatus in order of page.

Image forming apparatus capable of creating duplex mixed full color and

An image forming apparatus has a plurality of developing containers for developing an electrostatic latent image of a latent image carrier by toners having colors different from each other except for black; a black developing container for color for storing black toner for color and operated when the developed image on the latent image carrier every color is overlapped and transferred onto a transfer material to provide a color image; a black developing container for a monochromatic image for storing black toner for a monochromatic image and operated when the monochromatic image is obtained; and a device for arranging the respective developing containers such that the developing containers are opposite to the latent image carrier. The other image forming apparatuses are also shown.

Image forming apparatus having a separate black developer stored for a

An image forming apparatus for forming an image on one or both sides of a recording medium includes a rotatable photoconductive element on which latent images are optically written, a developer which develops the images to produce a primary toner image on the photoconductive element, a belt which faces the photoconductive element, and onto which the toner image is transferred when a paper sheet is not present. A charged roller is close to and above an upper portion of the belt and downstream from the photoconductive element. The charged roller holds the paper on the belt and also transfers toner onto the underside of the paper.

Image forming apparatus for forming an image on one or both sides of a

An image recorder capable of preventing a non-fixed toner image carried on a paper sheet from being rubbed with no regard to the elasticity or the thickness of the paper sheet. A belt transports the paper sheet with a non-fixed toner image. An upper guide plate and a lower guide plate face each other for guiding the paper sheet to a fixing device. The relative position of the upper and lower guide plates and the belt is variable to prevent the non-fixed toner image from contacting the upper or lower guide plate.

Image recorder with variable fuser nip entry position

A fixing device including a heating roller and a pressure applying roller maintained in pressing contact with each other and allowing a toner image bearing recording sheet to pass therebetween has a heat insulating structure enclosing at least a portion of the fixing device and a multiple wall structure for defining an air passage.

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Narashino, Japan

Yasunori Kawaishi