Canon Kabushiki Kaisha

Naoki Enomoto

Tatsuya Kobayashi

Tetsuya Kobayashi

Yoshiro Saito

Hiroshi Sasame

Toshiaki Miyashiro

Akihiko Uchiyama

Akihiko Takeuchi

Haruo Fujii

Takaaki Tsuruya

Tatsuhiko Hayakawa

Yoichiro Maebashi

Takashi Shibuya

Masaru Shimura

Seiji Saito

Takehiko Suzuki

Takamitsu Soda

Motoi Katoh

Youichirou Maebashi

Noriaki Sato

Kazuhiro Funatani

Arihiro Yamamoto

Takao Aoki

Motoi Kato

Toru Ishigaki

Koichi Suzuki

Satoshi Shimizu

Hideo Nanataki

Tomio Noguchi

Takashi Kawana

Akira Ito

Takao Kume

Kazuhisa Kemmochi

Toshihiko Ochiai

Hiroaki Kawakami

Katsuhiko Nishimura

Masao Nakano

Noriyuki Yanai

Toshifumi Moritani

Hideo Kimata

Tomoyuki Ohkura

An image forming apparatus includes a plurality of movable image carriers, a movable intermediate transfer body, and a contacting member separably contacting to the intermediate transfer body at a contacting position. A position for transfer between a first image carrier and the intermediate transfer body defines a first transfer position. A position for transfer between a second image carrier and the intermediate transfer body defines a second transfer position. A toner image formed on said intermediate transfer body is again transferred onto a transfer material after passing through said first transfer position and said second transfer position. The latent image formation on the first image carrier is done at a time different from a contacting operation of the contacting member.

Image forming apparatus

An image forming apparatus includes an image carrying member and an intermediate transfer body in an endless shape movable and receivable of toner images from said image carrying member at first and second transfer positions. The following relationship is satisfied where a distance from the first transfer position to the second transfer position along the moving direction of the intermediate transfer body is denoted as Lab, a circumference of the intermediate transfer in the moving direction is denoted as Lr, and a length of the toner image formed on the intermediate transfer body is denoted as Lm&#x2212;Lr&#x2212;Lm&#x3e;Lab.

Imaging forming apparatus

An image forming apparatus includes a first image bearing member for bearing a toner image; a second image bearing member for bearing the toner image; a transfer member opposed to the first image bearing member with the second image bearing member therebetween, wherein a voltage is applied to the transfer member to transfer the toner image from the first image bearing member onto the second image bearing member, and wherein a resistance Rt of the transfer member and a resistance Rb of the second image bearing member satisfy Rt/Rb&#x2267;1.0.

Image forming apparatus featuring a resistance relationship between an image bearing member and a transfer member

An image forming apparatus includes a first image bearing member carrying a toner image, and a movable second image bearing member carrying a toner image. The toner image on the first image bearing member is transferred to the second image bearing member at a first transfer portion, and the toner image on the second image bearing member is transferred to a transfer material at a second transfer portion. The apparatus also includes a charging member contacting the second image bearing member arranged on a downstream side of the second transfer portion and on an upstream side of the first transfer portion in a moving direction of the second image bearing member, and a mark portion having a thickness and being formed on the second image bearing member. A contact region between the charging member and the second image bearing member does not overlap with the mark portion in a direction perpendicular to the moving direction of the second image bearing member.

An image forming apparatus includes a first image bearing member and a second shiftable image bearing member. A first transferring member transfers a toner image formed on the first image bearing member to the second image bearing member at a first region. A second transferring member transfers a toner image formed on the second image bearing member to a transferring material at a second region. A first electrifier is provided downstream of the second region and upstream of the first region in a shifting direction of the second image bearing member. A second electrifier is provided downstream of the second region and upstream of the first electrifier in the shifting direction. A voltage applying unit applies a voltage to the first and second electrifiers to transfer toner adhered to the first and second electrifiers onto the second image bearing member.

The present invention provides an image forming apparatus comprising an image bearing member for bearing a toner image, a movable intermediate transferring member, a first charging member for charging toner on the intermediate transferring member when it is applied with a voltage including an AC component, and a second charging member for charging toner on the intermediate transferring member when it is applied with a DC voltage, the second charging member being located on an upstream side of the first charging member with respect to a moving direction of the intermediate transferring member, wherein a toner image on the image bearing member is temporarily transferred to the intermediate transferring member and then transferred to a transfer material.

Image forming apparatus with first and second charging members for charging residual toner

An image forming apparatus includes an image bearing means for bearing a toner image; an intermediary transfer member, wherein the toner image is electrostatically transferred from the image bearing means onto the intermediary transfer member, and then transferred from the intermediary transfer member onto a transfer material; wherein the intermediary transfer member includes a first layer and a second layer, provided on the first layer, for receiving the toner image from the image bearing means, and wherein the second layer has a volume resistivity smaller than that of the first layer.

Image forming apparatus with intermediary transfer member

An image forming apparatus includes an image bearing member; a belt for transferring an image from the image bearing member onto a recording material; transferring means for transferring the image from the image bearing member toward the belt; wherein the transferring means presses against the image bearing member through the belt; a tension member for applying tension the belt; wherein the belt is extended around the transferring means and the tension member; releasing means for releasing a tension applied to the belt by the tension member; separating means for separating the transferring means from the belt.

Image forming apparatus and belt unit detachably mountable thereto

An image forming apparatus is provided with photosensitive drums for forming latent images by irradiation of light reflected by a polygon mirror and a fixing device for fixing toner images corresponding to the latent images on a sheet material. Deterioration of an image to be formed is prevented if reflective surfaces of a reflective polyhedron are thinned out in reducing a process speed of image formation. This apparatus is further provided with a control unit for, if the number of surfaces of the polygon mirror is m (where m is an integer of three or more), performing a control for selecting n such that m/(n&plus;1) is not an integer as a relation between m and n and performing a control for making n surfaces unused as a reflective surface of light among continuous n&plus;1 surfaces of the reflective polyhedron in decelerating the image forming process.

Image forming apparatus and image forming method featuring image formation in two, different-speed modes

An image forming apparatus is capable of improving throughput, preventing deterioration of developer and preventing shortening of the life of a developing apparatus. In the image forming apparatus, an image holding member holds an electrostatic latent image and a developer carrier carries developer to a developing portion, and a speed ratio between the image holding member and the developer carrier varies according to an image ratio.

Speed ratio between an image holding member and a developer carrier varies according to an image ratio

A color image forming apparatus has developing unit, an image bearing member capable of bearing thereon toner images of plural colors formed by the developing unit, a rotatable intermediate transferring member, transferring unit for transferring the toner images of plural colors on the image bearing member to the intermediate transferring member at a first transferring position in electrostatically superposed relationship with one another, and a charger for charging any residual toner remaining on the intermediate transferring member after the toner images on the intermediate transferring member transferred by the transferring unit have been transferred to a transfer material at a second transferring position to a polarity opposite to the regular charging polarity of the toners in the developing unit. Simultaneously with the next toner image on the image bearing member being transferred to the intermediate transferring member at the first transferring position by the transferring unit, the residual toner charged by the charger is transferred to the image bearing member at the first transferring position by the transferring unit, and the first toner image transferred from the image bearing member to the intermediate transferring member at the first transferring position by the transferring unit is a black toner image.

Color image forming apparatus which prevents the scatter of color characters and lines

It is an object of this invention to provide an image processing apparatus which, when nonmagnetic mono-component development is performed, prevents the formation of white gaps in pattern boundaries between different colors and thereby prevents degradation in the image quality of the formed image. To achieve this object, in one embodiment of the invention, the density value VD(n) of the nth pixel on a certain line is applied to the A input terminal of a selector 207, and the density value VD(n-1) of the (n-1)th pixel is applied to the B input terminal of the selector 207. A subtracter 203 calculates the increase of VD(n) from VD(n-1). If a comparator 204 determines that the increase is a predetermined value C1 or less, a selection signal in the selector 207 is so set that the terminal B (the value of the immediately preceding pixel) is selected.

Image processing apparatus and method having improved color-boundary

In an image forming apparatus according to the present invention, the toner images of the plural colors on the intermediate transfer member are electrostatically transferred to a transfer material, and the image forming charges the toner image of a color, among the toner images of the plural colors formed on the intermediate transfer member, different from the last color in such a manner that the charge amount per unit weight of the toner image of the different color becomes 0.5 to 1.5 times of the charge amount per unit weight of the toner image of the last color, after the formation of the toner image of the last color on the intermediate transfer member and prior to the transfer of the toner images of the plural colors on the intermediate transfer member to the transfer material.

An image forming apparatus includes an image bearing member for bearing a toner image; a movable intermediary transfer belt extended around a plurality of supporting shafts, the intermediary transfer belt includes a core member and elastic layers sandwiching the core member, wherein a toner image on the image bearing member is transferred onto the intermediary transfer belt, and the toner image on the intermediary transfer belt is transferred onto a transfer material; wherein a distance r (mm) between a center of such one of the supporting shafts as has a minimum diameter and a center of the core member, a distance L.sub.1 (mm) between the center of the core member and a surface of the intermediary transfer belt where toner image transfer occurs, a distance L.sub.2 (mm) between a surface Of the core member and the surface of the intermediary transfer belt where the toner image transfer occurs, and a size t (mm) of the core member measured in a direction perpendicular to a movement direction of the intermediary transfer belt, satisfy:

Image forming apparatus and method for manufacturing intermediary

An image forming apparatus includes an image bearing member for bearing an image; an intermediary transfer member onto which an image is transferred from the image bearing member at a first transfer position and from which the image thus transferred is transferred onto a transfer material at a second transfer position; a contact member provided at an image bearing side of the intermediary transfer member, the contact member being capable of forming a nip between the intermediary transfer member; a supporting member for supporting the intermediary transfer member at a position opposite from the nip; a sum of a resistance value of the contact member and a resistance value of the supporting member is not more than 1/10 of a resistance value of the intermediary transfer member; and the contact member and the supporting member are contacted to the intermediary transfer member, and when no transfer material is present at the nip, a voltage is detected while a predetermined current is applied between the contact member and the supporting member through the intermediary transfer member.

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Ibaraki-ken, Japan

Naoki Enomoto