Canon Kabushiki Kaisha

Takayasu Yuminamochi

Akihiko Takeuchi

Koichi Tanigawa

Hiroto Hasegawa

Yasumasa Ohtsuka

Hideo Nanataki

Masaru Shimura

Yasunari Kobaru

Hiroshi Sasame

Hideyuki Yano

Koichi Hiroshima

Yasushi Sato

Tomoyuki Makihira

Kimio Nakahata

Masaharu Ohkubo

Takashi Narahara

Tomohiro Nakamori

Yukihiro Ohzeki

Kazuaki Ono

Junji Araya

Kenji Kanari

Masao Ando

Tatsunori Ishiyama

Minoru Matsuguma

Tomio Noguchi

Junichi Kimizuka

Toshiyuki Yoshihara

Eiichi Imai

Eiji Uekawa

Tetsuo Saito

Hiroaki Sakai

Hiroki Kisu

Norio Hashimoto

Yasuhiro Nakata

Yoshiro Tsuchiya

Kei Sawanaka

Kenji Nagata

Yasumasa Otsuka

Fumitaka Aoki

Hirokazu Ikenoue

An image forming apparatus includes a fixing unit having a rotating member with a surface layer, a pressing member that forms a fixing nip portion to sandwich and to transport a recording material with the rotating member, and a heater that heats the rotating member. A rotating member temperature sensor detects a temperature of the rotating member, and a wearing amount acquisition portion acquires a wearing amount of the surface layer of the rotating member. The wearing amount acquisition portion acquires the wearing amount corresponding to the temperature detected by the rotating member temperature sensor, and acquires the wearing amount per recording material. The wearing amount per recording material is different depending on the temperature detected by the rotating member temperature sensor. In addition, a control temperature setting portion sets a control temperature of the heater according to the wearing amount.

Image forming apparatus that controls a temperature of at least one of a rotating member based on a wearing amount of the rotating member and a pressing member based on a hardness change amount of the pressing member

The image forming apparatus has an image bearing member for bearing a toner, a transfer device which forms a transfer area in cooperation with the image bearing member for transferring the toner on the image bearing member onto a recording material, a charge elimination device which is opposed to the recording material at an upstream side of the transfer area in a conveying direction of the recording material thereby eliminating a charge on the recording material, and a control device which controls the recording material so as to form a loop in a position opposed to the charge elimination device, wherein the recording material forms a loop by the control device thereby approaching to the charge elimination device.

Image forming apparatus with conveying device urging a recording material toward a charge eliminating member

An image forming apparatus includes an image bearing member, a transferring device for transferring an image formed on the image bearing member to a transfer material, a transporting device for transporting the transfer material, a regulating member for regulating the transport direction of the transfer material. The charge eliminating member includes a charge eliminating portion and a supporting portion for supporting the charge eliminating portion. The regulating member has a top portion most, which protrudes in a direction from the supporting portion toward the charge eliminating portion of the charge eliminating member. When the transfer material is not being transported, a length from a boundary portion of the regulating member between the charge eliminating portion and the supporting portion to a distal end of the charge eliminating portion is defined as &ldquo;a&rdquo; (mm), a length from the boundary portion to the transport plane of the transfer material in a direction along the charge eliminating portion is defined as &ldquo;b&rdquo; (mm), and a length from the boundary portion to the top portion of the regulating member is defined as &ldquo;c&rdquo; (mm), wherein the conditions that a&minus;b&gE;0.5 (mm) an a&minus;b&lE;b and a<c are satisfied.

Image forming apparatus

In an oilless fixing apparatus of an image heating apparatus, a surface of a fixing roller or a pressure roller tends to be abraded by a separating claw if the contact pressure thereof is high, whereby the service life of the fixing roller or the pressure roller is often shortened. If the radius of curvature of the tip of the separating claw is reduced, there may be applied an excessively large force on the tip of the separating claw and the fixing roller or the pressure roller may be fatally damaged.

Image fixing apparatus having separating claw

A sheet attachment detecting apparatus includes a rotary member which is rotatable for conveying a sheet and whose surface is electrically conductive, an electrically conductive member which can be abutted on and separated from the surface of the rotary member, and an attachment detector which applies a power to the rotary member and the electrically conductive member for detecting the attachment of the sheet around the rotary member.

Sheet attachment detecting apparatus, fixing apparatus and image forming apparatus

A sheet conveying apparatus and an image forming apparatus include a transfer roller which transfers a developer developing an electrostatic latent image on a photosensitive drum to a sheet, a pair of registration rollers which nip the sheet into a conveying nip formed by a pair of rotary members and conveys the sheet to the transfer roller, and an upper transfer guide for leading the sheet from the pair of registration rollers to the transfer roller. In addition, a conveyance regulating member regulates a conveying direction of the sheet conveyed by the pair of registration rollers and brings the sheet into contact with the upper transfer guide.

Sheet conveying apparatus and image forming apparatus

A fixing apparatus has a first rotating member, a first heating device for heating the first rotating member, a second rotating member forming a nip together with the first rotating member, and a second heating device for heating the second rotating member wherein a recording material bearing an unfixed image thereon is nipped and conveyed at the nip in such a manner that the unfixed image is in contact with the first rotating member and is fixed by heating on the recording material. A voltage applying device applies voltage to create potential difference between the first rotating member and the second rotating member, and the second rotating member has a conductive parting layer with a surface resistance of 10 &OHgr; or less on a surface thereof.

Fixing apparatus with first and second heating rotation members having a potential difference

A fixing apparatus prevents the offset of toner onto a fixing roller, by forming a surface mold release layer made of pure fluororesin material on a core member of the fixing roller and by applying a bias voltage to the fixing roller.

Fixing apparatus preventing leakage of electric current from inner surface of fixing roller

An image forming apparatus includes an image bearing member and a transfer rotary member for transferring a toner image from the image bearing member onto a transfer material. An applying device applies a constant current to the transfer rotary member. A detector detects a voltage generated in the transfer rotary member when the applying device applies the constant current to the transfer rotary member. A controller controls a voltage applied to the transfer rotary member during a transfer operation. The detector detects the voltages during intervals between consecutive transfer materials, and the controller controls the voltage on the basis of the voltages detected during different intervals.

Image forming apparatus using transfer roller having low resistance unevenness in circumferential direction

An image forming apparatus includes an image bearing body for bearing a toner image, a transfer member for electrostatically transferring the toner image from the image bearing body, a cleaning bias applying device for electrically cleaning the transfer member by applying a cleaning bias to the transfer member, wherein the cleaning bias applying device applies the cleaning bias to the transfer member after a one image forming job is finished, and a controller for controlling the application of the cleaning bias in accordance with the number of sheets to be image-formed in one image forming job.

Image forming apparatus with a bias control feature

A charging roller is set in contact with a chargeable member to charge the chargeable member by application of voltage. The charging roller has an electroconductive support, an elastic layer formed thereon, and at least one coating layer formed on the elastic layer. The charging roller has surface roughness of not more than 8 .mu.m, and Asker C hardness (A) of the elastic layer, and micro-rubber hardness (B) of the charging roller satisfy the relations below:

Charging roller, and process cartridge and image-forming apparatus

Fixing apparatus having a fixing roller with a non-adhesive surface layer

The present invention relates to an image forming apparatus which comprises an image bearing member for bearing a toner image, a transfer charger for transferring the toner image from the image bearing member to a transfer material, and an electricity removing member for removing electricity from the transfer material to separate the transfer material from the image bearing member, and wherein, when the electricity is removed from the transfer material by the electricity removing member, a potential level applied to the electricity removing member is selected so that the potential level at end portions of the transfer material becomes greater than the potential level at a central portion of the transfer material along a transfer material shifting direction, thereby improving separation of the transfer material from the image bearing member.

Image forming apparatus with two-potential-level electricity removing

In a fixing device used in an image forming apparatus, temperature changes in a heating member are reduced by gradually reducing a power supply duty ratio while the heating member is subjected to temperature control aiming at a set temperature.

Fixing device

An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; an image transfer device for transferring the toner image onto a transfer material at a transfer position, the transfer device including a rotatable member contactable to such a side of the transfer material as is opposite from a side contactable to the image bearing member and an electric field forming device for forming an electric field between the image bearing member and the rotatable member; wherein the electric field forming device forms a first electric field effective to transfer the toner from the rotatable member to the image bearing member and a second electric field which is opposite in a direction from the first electric field during a period in which the transfer material is absent at the transfer position, wherein each of the first and second electric fields is formed at least for a period required for the entire surface of the rotatable member passes through the transfer position.

Growing community of inventors

Shizuoka-ken, Japan

Takayasu Yuminamochi