Canon Kabushiki Kaisha

Toshio Miyamoto

Masahiko Suzumi

Masahiro Goto

Satoru Izawa

Koichi Tanigawa

Katsuhiko Nishimura

Yozo Hotta

Hiroto Hasegawa

Junji Araya

Yasushi Sato

Akihiko Takeuchi

Kimio Nakahata

Koji Nihonyanagi

Kazuaki Ono

Kenji Kanari

Tatsunori Ishiyama

Shunji Nakamura

Masanobu Saito

Yukihiro Ohzeki

Yohji Tomoyuki

Yuko Ohkama

Hiroshi Mano

Akira Kuroda

Minoru Hayasaki

Aoji Isono

Michio Uchida

Yuki Nishizawa

Koichi Hiroshima

Seiji Uchiyama

Keiji Okano

Hiroki Kisu

Masami Takeda

Makoto Takeuchi

Hideo Nanataki

Hiroshi Sasame

Hideyuki Yano

Yasumasa Ohtsuka

Yoji Serizawa

Eiji Uekawa

Koichi Okuda

Shinichi Tsukida

Nobukazu Adachi

Takahiro Inoue

Akira Hayakawa

Hajime Motoyama

Koichi Suwa

Minoru Matsuguma

Yoji Tomoyuki

Yuzo Isoda

Harumi Kugoh

Saturo Izawa

A fixing device configured to fix an image on a recording material, includes: a rotary member including an electroconductive layer; a coil which has a spiral shaped portion and is disposed in the inside of the rotary member; and a core disposed in the spiral shaped portion; with magnetic resistance of the core being, with an area from one end to the other end of the maximum passage region of the image on the recording material regarding the generatrix direction, equal to or smaller than 30% of combined magnetic resistance made up of magnetic resistance of the electroconductive layer and magnetic resistance of a region between the electroconductive layer and the core.

Image fixing device

The image heating apparatus for heating a toner image formed on a recording material, comprising, a rotatable member; heating device for heating an outer peripheral surface of the rotatable member, the heating device including a heater for forming a heating nip portion in cooperation with the rotatable member; back-up device for forming a conveying nip portion in cooperation with the rotatable member, the conveying nip portion conveying the recording material; and control device for controlling a temperature of the heater and a rotation of the rotatable member, wherein the apparatus has a cleaning mode to remove toner from the heating device, and the control device rotates or reversely rotates the rotatable member in a condition that the heater dissipates heat in the cleaning mode. By the virtue of the present invention, it prevents stain caused by the off-set of toner the recording material in an image heating apparatus.

Image heating apparatus having heater for externally heating fixing roller

An image forming apparatus which can prevent the electric discharge when the trailing edge of a recording material passes a transferring position, and yet can stabilize the surface potential of a photosensitive drum. A controller changes a transfer bias voltage Vt during the supply of paper to 0 V before the trailing edge of recording paper arrives at a transferring nip part, changes it to a transfer bias voltage Vduring the non-supply of paper after the trailing edge of the recording paper has passed the transferring nip part, and changes a charging bias voltage to a charging bias voltage smaller than a normal charging bias voltage when an area on the photosensitive drum to which 0 V has been applied passes a charging nip portion. The transfer bias voltage Vduring the non-supply of paper is smaller than the transfer bias voltage Vt during the supply of paper.

Image forming apparatus

A switching timing condition for controlling the switching timing from first transfer bias during a non-transfer process to second transfer bias during a transfer process is recognized, and the switching timing of the transfer bias from the non-transfer process to the transfer process is switched according to the content of the recognized switching timing condition.

Image forming apparatus and image forming method

An image heating apparatus includes a rotatable member; back-up means for cooperating with the rotatable member to form a feeding nip for feeding a recording material; heating means for heating an outer peripheral surface of the rotatable member, the heating means including a heater in the form of a plate cooperable with the rotatable member to form a heating nip.

Image heating apparatus with heater in form of a plate cooperable with a rotatable member to form a heating nip

In a method and apparatus for controlling the temperature of a fixing device of the film heating type and the pressure rotary member driving type and an image forming apparatus provided with this fixing device, at the start of printing, the output of a thermistor near a heater is detected, and when the temperature difference &Dgr;T&equals;T &minus;T between the detected temperature T and the fixing temperature T is smaller than a desired temperature T , the raising timing of the heater is delayed. Thereby, a pressure roller is not-excessively warmed at hot start and slip can be prevented. Also, in the image forming apparatus having the film heating type fixing device, in the next printing after the lapse of a predetermined time after the termination of a printing operation, the target temperature and heater electrical energization starting timing of the fixing device are changed in conformity with the temperature of the fixing device. The apparatus has an atmospheric temperature sensor, and in the next printing after the lapse of a predetermined time after the termination of a printing operation, the target temperature and heater electrical energization timing of the fixing device during the initial rotation operation in the printing, operation are changed in conformity with the atmospheric temperature detected by the atmospheric temperature sensor and the temperature of the fixing device.

Method and apparatus for controlling the temperature in a fixing device of an image forming apparatus

An object of the present invention is to provide an image forming apparatus having a fixing device, which can obtain good fixing ability while preventing occurrence of hot offset. The present invention provides an image forming apparatus that has image forming means for forming an image on a recording material, a heating member for heating the image on the recording material, a backup roller forming a nip with the heating member, a temperature detecting element for detecting a temperature of an atmosphere, and control means for controlling a power supply to the heating member, wherein when a print signal is inputted, the control means controls power supply (electrical communication) to the heating member in such a manner that the heating member maintains a set temperature in accordance with a detection temperature of the temperature detecting element, and, thereafter, a fixing operation is effected.

The present invention relates to an image heating apparatus in which an image on a recording material is heated by heat from a heater via a film, and the film contacts a surface of the heater opposite to a surface thereof on which heat generating members are provided.

Image heating apparatus and heater

The present invention relates to an image heating apparatus in which a heater being controlled by an output from a temperature detecting element to obtain a predetermined temperature and an image on a recording material being heated by heat from the heater via a film, the heater having a first heating member disposed along a longitudinal direction of a base material and heated by energizing and a second heating member shorter than the first heating member, the first heating member being disposed on an upstream side of the second heating member with respect to a moving direction of the recording material, and when a first size recording material is heated, the first heating member being energized and the second heating member being not energized, when a second size recording material smaller than the first size recording material is heated, the first heating member and the second heating member being energized.

Image heating apparatus and heater for heating image

An image forming apparatus has an image forming unit for forming an image on a recording material and a fixing unit for fixing the image to the recording material by nipping and conveying the recording material, the fixing unit including a heater which does not generate heat during a standby period in which a printing operation can be started. The heater generates heat for a predetermined period after the start of power supply to the apparatus and then the apparatus is rendered capable of the printing operation.

Image forming apparatus with image fixing means of low heat capacity

The present invention relates to an image heating apparatus in which an image on a moving recording material is heated by a heat from a heater, the heater has an elongated substrate extending in a direction perpendicular to a shifting direction of the recording material, and a first heat generating body and a second heat generating body for generating heat by energization and provided on the substrate along a longitudinal direction thereof, the first and second heat generating bodies are disposed side by side in a direction perpendicular to the longitudinal direction of the substrate, and the first heat generating body has a first heat generating portion, and a second heat generating portion provided at a longitudinal end of the first heat generating portion and having a heat generating amount per unit length smaller than that of the first heat generating portion, and, when the width of the recording material is detected to be smaller than a predetermined width by the detecting member, the first heat generating body is energized, and, when the width of the recording material is detected to be greater than the predetermined width, the second heat generating body is energized, and the detecting member is provided at a position corresponding to the second heat generating portion in the longitudinal direction of said substrate.

Image heating apparatus

The present invention provides an image fixing apparatus which comprises a heater for generating heat upon receiving electric power supply thereto, a film movable with an unfixed image on a recording material while being in contact with said heater, a backup roller for forming a nip with said heater, with said film being interposed in the nip, and fixing condition setting means for setting an image fixing condition according to a size of the recording material conveyed to the nip in a preceding image fixing operation and a size of the recording material conveyed to the nip in the current image fixing operation.

Image fixing apparatus

The present invention provides an image forming apparatus having an image bearing member for bearing a toner image, and a transfer rotary member for forming a nip between the transfer rotary member and the image bearing member, the transfer rotary member being provided at its surface with a solid layer and serving to transfer the toner image from the image bearing member onto a transfer material at the nip, and wherein a moving speed of a surface of the transfer rotary member at the nip is greater than a moving speed of a surface of the image bearing member at the nip, and a surface friction force of the transfer rotary member is greater than a surface friction force of the image bearing member by 3 to 20 times.

Image forming apparatus having transfer rotary member with surface

In an image heating apparatus, a film has one face in sliding contact with a heater having a heat generating portion on a substrate. The other face of the film contacts a recording material bearing an image. The film moves with the recording material and the image on the recording material is heated by heat generated by the heater which is transmitted through the film. A temperature detecting element detects the temperature of the heater. The heat generating portion of the heater has a first heat generating portion and a second heat generating portion on the downstream side of the first heat generating portion with respect to the moving direction of the film. The middle of the temperature detecting element is positioned at the upstream side of the middle between the first and second heat generating portions with respect to the moving direction of the film.

Heater having an offset temperature detecting element and image heating

Growing community of inventors

Numazu, Japan

Toshio Miyamoto