Sharp Kabushiki Kaisha Corporation

Ricoh Company, Ltd.

Yoshie Iwakura

Susumu Murakami

Kuniaki Nakano

Fumio Shimazu

Hideshi Izumi

Minoru Tomiyori

Kiyoshi Toizumi

Tomohiro Oikawa

Takuya Abe

Hiroshi Tachiki

Atsuyuki Katoh

Kouichi Yamauchi

Hiromu Yoshimoto

Takahiro Fukunaga

Tomoya Adachi

Takafumi Miyazaki

Atsushi Takehara

Akihiro Kawasaki

Yasuhiro Fujiwara

Takeshi Yamashita

Takashi Hori

Masanori Yamada

Hideki Ohnishi

Takahisa Narikiyo

Tomohiko Fujii

Seiichi Yoshida

Yoshihiro Mikuriya

Hiroshi Ishii

Hideaki Yasunaga

Masayuki Hagi

Toshiki Takiguchi

Naoki Nakatake

Yoshitaka Sekiguchi

Yoshinori Shirasaki

Hirokazu Yamauchi

Kazuoki Fuwa

Kazuyuki Ohnishi

Yuji Nagatomo

Yoichi Shimazawa

Yasutaka Maeda

Takateru Yamamoto

Yoshiaki Masuda

Yasushi Matsutomo

Yasuhide Matsuno

Hiroaki Kato

Yoshiaki Hiramoto

Motokazu Nakao

Shigeru Yoshida

Takahiro Sanada

Yuichi Kazaki

Kyoko Abe

Toshihiko Takaya

Rumi Konishi

Rumi Miyazaki

Yoshiyuki Nagai

Akira Kohno

Yoshiaki Kojoh

Yoko Sawa

Mihoko Okada

Shin-ichirou Ohhashi

An image forming apparatus includes an image bearing member to bear a latent image on a surface thereof, a developing device to develop the latent image with toner, an intermediate transfer member, a secondary transfer member, a cleaning device, and a main body. The cleaning device cleans the secondary transfer member for a predetermined time period T1 during a startup operation after printing is completed normally before subsequent printing. The main body houses the image bearing member, the developing device, the intermediate transfer member, the secondary transfer member, and the cleaning device. At least one of the image bearing member and the developing device constitutes a process cartridge detachably attachable relative to the main body, and in a case in which the process cartridge is installed in the main body, the cleaning device cleans the secondary transfer member for a time period T2 extended from the predetermined time period T1.

Image forming apparatus

Provided is a color image forming apparatus that includes: image carriers that form toner image of black and other colors; an intermediate transfer body that makes contact with the image carriers; and transfer units that transfer the toner images on the image carriers to the intermediate transfer body. A line velocity difference is set between the image carriers and the intermediate transfer body. An accelerated cohesion degree of toner is equal to or larger than 54%. A linear velocity difference Xbetween the image carrier for black and the intermediate transfer body satisfies a relation of 0&#x3c;X&#x2266;1.2 mm/sec. A linear velocity difference Xbetween the image carriers for the colors and the intermediate transfer body satisfies a relation of 2.1&#x2266;X&#x2266;4.0 mm/sec.

Color image forming apparatus with a line velocity difference set between image carriers

An image forming apparatus including at least one latent image carrier, an image forming unit to form a toner image on the at least one latent image carrier based on image data, a transfer body onto which the toner image formed on the at least one latent image carrier is transferred in one or more valid image ranges, a non-image range determiner to determine a non-image range on a surface of the transfer body onto which the toner image is not transferred, a surface detector to detect the surface of the transfer body in the non-image range, and a toner determiner to determine whether or not toner is present in the non-image range based on a result detected by the surface detector.

For an electrostatic latent image formed on an image carrier (), besides an operation forming an 'image forming electrostatic latent image' used to form the primary image, an operation is executed that forms an 'electrostatic latent image for removing developer' for removing developer that resides on a developer supply member () for a predetermined time period onto the image carrier (). Thus, developer is nearly eliminated from residing on this developer supply member () in an overcharged state for a long period of time, and generation of a fogged image is avoided as much as possible.

Image forming apparatus capable of preventing worsening of image quality caused by excessively charged developer

In an image forming apparatus, an intermediate transfer belt is made of a resin film and is supported by a plurality of rollers. A driving roller that is one of the plurality of rollers, drives the intermediate transfer belt, and also functions as an opposing unit with respect to a secondary transfer roller. The driving roller is made of metal, and applies a bias to at least secondary transfer units, at least at a time of performing primary transfer to a plurality of image bearing bodies.

Image forming apparatus including a metallic driving roller

An image forming unit includes four photoconductors, a belt extended around a driving roller and an extension-cum-primary transfer roller. Three primary transfer rollers sandwich the belt in association with a corresponding photoconductor. The extension-cum-primary transfer roller serves both as an extension roller and a primary transfer roller.

Tandem intermediate-transfer type image forming apparatus

Provided is an image forming method that comprises a charging step, an exposing step, a developing step, an intermediate transfer step and a secondary transfer step, wherein the diameter R (mm) of a secondary transfer roller used in the secondary transfer step and the distance A (mm) between a nip center of the secondary transfer roller and a site where paper contacts with a secondary transfer belt at ingress side satisfy the following relation, and the charge amount Q (&#x3bc;C/g) of the toner going into the secondary transfer step satisfies the following relation./40&#x3c;/1515/&#x3c;35/.

Image forming method and apparatus including a relationship between secondary roller diameter and recording medium ingress position

A primary transfer unit includes transfer units for performing a toner transfer from image carriers onto a transfer belt. Each of the transfer units is formed with a metallic roller. The metallic roller is arranged so as to satisfy &#x3b8;1&#x3c;&#x3b8;2, where an angle of the endless belt with respect to a tangent to the image carrier, on a side upstream of rotation of the endless belt to a transfer nip region where the image carrier and the endless belt are in contact is &#x3b8;1, and an angle of the endless belt with respect to the tangent, on a side downstream of rotation of the endless belt to the transfer nip region is &#x3b8;2.

Primary transfer unit of image forming apparatus

A discharge unit is disposed downstream of a principal transport path of a compound machine, and a shifter function is provided in this discharge unit. By shifting the paper passage position relative to a photosensitive drum when printing the front side and the paper passage position relative to the photosensitive drum when printing the back side, the region in which the surface electric potential of the photosensitive drum increases is diminished, and the region in which photographic fog is generated is made smaller. Thus, when printing the second and subsequent sheets, even when a slight amount of displacement of the transport position of the recording paper occurs, it is possible to suppress that recording paper making contact in the photographic fog region on the photosensitive drum, and defective printing can be prevented.

In an image forming apparatus that uses a charging unit to charge a photosensitive drum, forms an electrostatic latent image by carrying out image exposure according to image information, and transfers to a paper the electrostatic latent image by developing the electrostatic latent image into a visible image using a developer so that the image information is presented, an exhaust ductfor exhausting air that contains ozone produced within a drum unit, which includes a photosensitive drumand a charging unit, and a ductfor taking in air, which draws in fresh air, are provided within the drum unitso that ventilation of the drum unitcan be carried out with excellent efficiency.

Image forming apparatus having charging unit with separate intake and exhaust ducts

A color image forming apparatusincludes: a multiple number of process printing units, each having an photoreceptor drumfor bearing a developer image formed with a toner corresponding to a different color of color-separated image information; a transfer beltto which a multiple number of developer images are comprised in layers; and a transfer rollerfor transferring the developer images that have been comprised in layers on transfer belt, all at once, to recording paper, wherein the multiple number of process printing unitsare arranged along transfer belt, and is characterized in that among the developer images to be transferred from the photoreceptor drumsof multiple image forming unitsonto transfer belt, the toner for the developer image of the color to be transferred first is specified to produce a base-layer of the color images of information.

Color image forming apparatus using base-layer

A combined resistance R=Vt/I(MO) of a transfer belt () and a recording sheet obtained when a transfer current I(&#x3bc;A) passes through the transfer belt () and the recording sheet upon application of a first transfer bias voltage Vt(V) to a transfer roller () from a high-voltage power source () and a combined resistance R=Vt/I(MO) of the transfer belt () and the recording sheet obtained when a transfer current I(&#x3bc;A) passes through the transfer belt () and the recording sheet upon application of a second transfer bias voltage Vt(V) to the transfer roller () from the high-voltage power source (), are established to have the relationship: R/R=7 ?(I)therebetween.

Belt transfer apparatus and image forming device

An image forming apparatus is constituted so as to be equipped with transfer apparatus(es) having transfer roller(s) electrostatically transferring development image(s) from photosensitive drum(s) to transfer medium/media, and so as to be provided with transfer medium guide unit disposed downstream in transfer medium transport path(s) from location(s) at which photosensitive drum(s) oppose transfer roller(s), and such that transfer medium guide location(s) of transfer medium guide means is/are variable.

Device for preventing contact between transfer body and transfer medium tail edge portion in image forming apparatus

A color image forming apparatus includes: a multiple number of process printing units, each having an photoreceptor drum for supporting a developer image formed with a developer corresponding to each color of color-separated image information; a transfer belt to which the developer images formed on the photoreceptor drums are transferred; and a transfer roller for transferring the transferred developer image to recording paper, and is constructed so that the transfer belt is formed of a material which makes it possible for the transfer belt to attenuate the voltage charged thereon by 1,000 V or greater while it moves from a position where secondary transfer is performed to a position where the initial primary transfer is performed.

Color image forming apparatus including a voltage attenuating intermediate transfer belt

A cleaning system includes a rotating member and a cleaning blade which is forced against a curved outer surface of the rotating member to scrape off matter to be removed (toner) which is present along the outer surface of the rotating member. The cleaning blade has greater hardness than the outer surface of the rotating member.

Cleaning system

Growing community of inventors

Higashiosaka, Japan

Yoshie Iwakura