Canon Kabushiki Kaisha

3m Innovative Properties Company

Katsuhiko Nishimura

Kimio Nakahata

Toshio Miyamoto

Koichi Hiroshima

Yasuo Yoda

Keiji Okano

Tatsunori Ishiyama

Yasushi Sato

Koichi Tanigawa

Masuo Yamazaki

Takashi Shibuya

Toru Kosaka

Satoshi Shimizu

Tatsuya Nakamura

Akihiko Takeuchi

Kaoru Seto

Akio Aoki

Seiji Sagara

Hiroto Hasegawa

Shinichi Tsukida

Kazuro Yamada

Masahide Hirai

Hiromichi Yamada

Takao Aoki

Masami Takeda

Michihito Yamazaki

Kouichi Suwa

Tohru Kosaka

Tooru Saitou

Tohru Saitou

Masahiro Suzuki

Makoto Takeuchi

Tatsuya Kobayashi

Shunji Nakamura

Koichi Sano

Hideo Nanataki

Hiroshi Sasame

Masanobu Saito

Hideyuki Yano

Yasumasa Ohtsuka

Takao Kume

Naoki Enomoto

Yukihiro Ohzeki

Koichi Okuda

Kazuaki Ono

Junji Araya

Yukihide Ushio

Akira Hayakawa

Jun Saito

Masahiro Okuda

Norio Hashimoto

Minoru Matsuguma

Yozo Hotta

Yoji Tomoyuki

Motoi Katoh

Yuzo Isoda

Akio Nemoto

Harumi Kugoh

Toshihiko Sugimoto

Kenichi Kobayashi

Akira Yuza

Katsunori Takeuchi

Yasuhi Sato

A developer bearing member includes a base body, a surface layer, and a plurality of concave portions provided on the surface layer, wherein a resistance value of the surface layer is 10&#x3a9;&#xb7;cm to 10&#x3a9;&#xb7;cm, the number of the concave portions per unit area is 2250/mmto 12254/mm, a major diameter of an opening of the concave portion is 8 &#x3bc;m to 20 &#x3bc;m, a depth of the concave portion is 2 &#x3bc;m to 5 &#x3bc;m, a dimensional tolerance of the major diameter is 0.5 &#x3bc;m or less, and a dimensional tolerance of the depth is 0.5 &#x3bc;m or less.

Developer bearing member, developing apparatus, and image forming apparatus

An image forming apparatus and method in which a controller is capable of executing image processing of its own are disclosed. The controller has an RF unit for processing image information, a halftone image processor, a density corrector and a patch generator. The engine includes a modulator corresponding to the RF unit, a halftone image processor different from that of the controller, a density controller, modulator and patch generator corresponding to the halftone processor of the engine, a sensor for sensing the density of formed patches, and a control unit for controlling the density of an image on the basis of a signal from the sensor. The engine sends the controller a signal relating to density control.

Image processing method, apparatus and controller

A sheet feed rollerincludes a shaft memberand an elastomeric layerprovided on the outer circumference of the shaft member. The shaft memberincludes a tubular supportand a pair of shaft sectionsextending in the axial direction to define a rotary axis of the shaft member. The elastomeric layeris formed of an elastic member separate from the shaft member, and attached to the outer circumferenceto be conformed with the profile of the supportof the shaft member. The elastomeric layerincludes a baseand a plurality of micro-structured elements, each having a three-dimensionally projected shape, formed on the surfaceof the base. Each of the plurality of micro-structured elementson the elastomeric layeris brought into frictional contact at a distal end thereof with the sheet medium and feed the same as the shaft member rotates.

Sheet feed apparatus, sheet separating member, sheet feed assembly and sheet separating assembly

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 fixing apparatus for use in an image forming apparatus such as a copying apparatus or a laser beam printer is disclosed. The fixing apparatus has a heater, a rotatable member having the heater therein, and a pressing member forming a nip by coming into contact with the rotatable member. The rotatable member is provided with a core and an elastic layer formed on the core, and the elastic layer has a JIS-A Standard rubber hardness not more than 5.degree..

Rotatable member having elastic layer and fixing apparatus having said

An image forming apparatus including a rotatable developing member having a plurality of developing devices for developing an image bearing member at a first developing station, and a second single developing device arranged upstream of the rotatable developing member for developing the image bearing member exclusively at a second developing station different from the first developing station. The second developing device has a cover portion covering the rotatable developing member, and a portion of the cover portion is disposed at a position spaced apart from a rotation axis of the rotatable developing member by a predetermined length in a horizontal direction away from the image bearing member. The rotatable developing member rotates in an opposite direction with respect to the direction of rotation of the image bearing member to prevent toner from scattering toward the optical system.

Image forming apparatus having a rotatable first developing member, and

The present invention provides an image forming apparatus which includes a movable image bearing member for bearing a toner image, a movable intermediate transfer member to which the toner image on the image bearing member is electrostatically transferred at a first transfer position, and a charger for charging residual toner remaining on the intermediate transfer member after the toner image on the intermediate transfer member has been electrostatically transferred onto a transfer material at a second transfer position with polarity opposite to charging polarity of the normal toner on the image bearing member. An electric field is formed so that the residual toner charged by the charger from the intermediate transfer member onto the image bearing member and a transfer of a next toner image from the image bearing member onto the intermediate transfer member are simultaneously performed at the first transfer position. Also included is a controller for controlling so that a relative position of a first toner image transferred to a first transfer material from the intermediate transfer member with respect to the intermediate transfer member and a relative position of a second toner image transferred to a second transfer material from the intermediate transfer member with respect to the intermediate transfer member are differentiated.

Simultaneous cleaning of residual toner and toner image formation

An image forming apparatus has an image bearing member; toner image forming unit for forming a toner image with non-magnetic toner on an image bearing member; intermediate transfer member contactable to the image bearing member and movable along an endless path; primary transfer unit for effecting primary image transfer of the toner image formed on the image bearing member onto the intermediate transfer member at a first transfer position; secondary transfer unit for effecting a secondary image transfer of the toner image from the intermediate transfer member on the transfer material at a second transfer position; and a residual toner charger for charging the residual toner remaining on the intermediate transfer member to a polarity opposite from a regular polarity thereof. After the secondary image transfer, the residual toner remaining on the intermediate transfer member is charged by the residual toner charger to the opposite polarity, and is then passed through the first transfer position during the primary image transfer, so that the residual toner is transferred back to the image bearing member substantially simultaneously with a next primary image transfer, thus removing the residual toner from the intermediate transfer member.

Image forming apparatus which back-transfers residual toner from an

In an image forming apparatus a toner image is transferred onto a transfer material using an intermediate transfer member. The image forming apparatus has an image bearing member; a toner image forming unit for forming a toner image on the image bearing member; an intermediate transfer member movable along an endless path in contact with the image bearing member; a bias voltage applicator for applying a bias voltage to transfer the toner image from the image bearing member onto the intermediate transfer member at a first transfer position of the intermediate transfer member; and an image transfer device for transferring the toner image from the intermediate transfer member onto the transfer material at a second transfer position of the intermediate transfer member, a residual toner charge for charging residual toner remaining on the intermediate transfer member after image transfer therefrom, to a polarity opposite from a regular polarity of the toner to permit the residual toner to transfer back, simultaneously with a next image transfer at the first transfer position, to the image bearing member when the residual toner passes through the first transfer position.

Image forming apparatus having cleaning device for cleaning intermediate

An image forming apparatus includes a first image-bearing member such as an electrophotographic photosensitive member, an intermediate transfer member for receiving a transferable image formed on the first image-bearing member, and contact transfer device for transferring the transferable image from the intermediate transfer member to a transfer material. The first image-bearing member has a surface layer having a dielectric constant .epsilon..sub.d, the intermediate transfer member has a surface layer having a dielectric constant .epsilon..sub.ITD and the contact transfer device has a surface layer having a dielectric constant .epsilon..sub.tr satisfying a relationship of; .epsilon..sub.d .ltoreq..epsilon..sub.ITD .ltoreq..epsilon..sub.tr. The intermediate transfer member exhibits a volume resistivity of 10.sup.6 -10.sup.10 ohm.cm (at an applied voltage of 1 kV), and the contact transfer device exhibits a volume resistivity of 10.sup.8 -10.sup.15 ohm.cm (at an applied voltage of 1 kV). As a result, it is possible to obtain high transfer efficiencies in both primary and secondary transfer over a wide transfer bias application range.

Image forming apparatus having dielectric constant relationship between

An image forming method, comprising the steps of forming an electrostatic image on a electrostatic image-bearing member, developing the electrostatic image with toner particles having a first shape factor (SF-1) of 100-150 and containing a low-softening point substance to form a toner image on the electrostatic image-bearing member, transferring the toner image on the electrostatic image-bearing member to an intermediate transfer member which has been voltage-applied, transferring the toner image on the intermediate transfer member to a transfer-receiving material by a transfer means which has been voltage-applied, and heat-fixing the toner image on the transfer-receiving material. The toner particles may preferably have a second shape factor (SF-2) of 100-140. The total of SF-1 and SF-2 may preferably at most 275, particularly at most 240, for improving transfer efficiency of the toner particles. The low-softening point substance may preferably be an ester wax having a long-chain (e.g., .gtoreq.C.sub.10) alkyl group. The image forming method is effective in providing a high-quality (full-color) toner image with high transfer efficiency and free from toner sticking.

Image forming method

This invention relates to a color image forming apparatus for forming a color image with dry developer, capable of preventing deterioration of image quality, resulting from contamination of optical components by the non-magnetic developer scattered from the developing unit. For this purpose there are provided, along the moving direction of an image bearing member effecting endless movement, charging means, optical means, first developing means utilizing developer containing a magnetic component, second developing means utilizing non-magnetic developer of a color different from that of the developer of the first developing means, and transfer means maintained in contact with or close to the image bearing member for transferring a developed image from the image bearing member to a recording material such as paper. A space containing the second developing means is enclosed by the shape of the first developing means, transfer means and image bearing member.

Image forming apparatus for forming color image with dry developer

A bias voltage including an AC voltage component is applied to a development sleeve. When the development sleeve opposes a non-image region of a photosensitive drum, a reference bias voltage including a constant current AC voltage component or a reference bias voltage including a constant voltage AC voltage component is applied to the development sleeve, and an AC voltage value or an AC current value applied to the development sleeve at that time is detected. An image formation factor is controlled on the basis of the detected AC voltage value or the detected AC current value.

Image forming apparatus using constant voltage or constant current AC

A developing apparatus includes an image bearing member for bearing an electrostatic image, a developer carrying member, opposed to the image bearing member to form a developing zone therebetween, for carrying a developer to the developing zone to develop an electrostatic latent image on the image bearing member, and oscillating bias means for applying an oscillating bias to the developer carrying member, wherein the oscillating bias includes a constant-current-controlled AC component and a constant-voltage-controlled DC component.

Developer carrying member utilizing oscillating bias having

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Yokohama, Japan

Katsuhiko Nishimura