Canon Kabushiki Kaisha

Hiroto Hasegawa

Akihiko Takeuchi

Koichi Tanigawa

Takayasu Yuminamochi

Yasumasa Ohtsuka

Hideo Nanataki

Hiroshi Sasame

Hideyuki Yano

Toshio Miyamoto

Satoru Izawa

Kazuaki Ono

Masahiro Goto

Masahiko Suzumi

Shinji Hashiguchi

Koji Nihonyanagi

Tatsunori Ishiyama

Akihito Kanamori

Yasumasa Otsuka

Yasushi Sato

Masaharu Ohkubo

Yukihiro Ohzeki

Eiji Uekawa

Satoru Taniguchi

Hiroki Kisu

Katsuhiko Nishimura

Toshiya Kaino

Masami Takeda

Yozo Hotta

Yuko Ohkama

Hideo Nanatani

Hiroshi Sato

Masaki Ojima

Kimio Nakahata

Katsuhiro Sakaizawa

Junichi Kato

Toshiyuki Yoshihara

Eiichi Imai

Tetsuo Saito

Hiroaki Sakai

Koichi Hiroshima

Kazushige Sakurai

Keiji Okano

Hiroaki Ogata

Fumiki Inui

Junji Araya

Kenji Kanari

Masaru Tsukada

Norio Hashimoto

Akira Unno

Ken Yokoyama

Yasunari Kobaru

Minoru Matsuguma

Takashi Honke

Fumihiro Arahira

Michihito Yamazaki

Kenji Nagata

Erika Asano

Harumi Kugoh

Fumitaka Aoki

Hirokazu Ikenoue

Yuko Okama

An image forming apparatus includes an image carrier to carry a toner image, intermediate, primary, and secondary transfer members, and a voltage application member. The voltage application member applies a voltage to the image carrier. The secondary transfer member is in contact with an outer circumferential surface of the intermediate transfer member. The toner image carried on the image carrier is primarily transferred onto the intermediate transfer member in a state where the voltage application member applies the voltage to the image carrier. The intermediate transfer member has a volume resistivity from 5×10Ω·cm to 2×10Ω·cm inclusive. A relation ρs1/ρs2≥1.5 is satisfied, where ρs1 denotes a surface resistivity which is measured from the outer circumferential surface of the intermediate transfer member and ρs2 denotes a surface resistivity which is measured from an inner circumferential surface of the intermediate transfer member.

Image forming apparatus

The image heating apparatus includes a heater having first and second and heat-generation segments each having a plurality of spaced-apart heat generating parts therein in the longitudinal direction respectively. The heat generating parts each have first and second electro-conductive patterns provided along the longitudinal direction on a substrate and overlapping in the longitudinal direction, and a heat generating resistor which electrically connects the respective overlapping regions of the first electro-conductive pattern and the second electro-conductive pattern with each other and generates heat by supplied electric power. It simultaneously prevents the temperature in a non-sheet feeding portion from rising and secures fixing properties in the gap between the adjacent heat generating parts.

Image heating apparatus and heater used for the image heating apparatus

The image heating apparatus for heating an image formed on a recording medium has an endless belt with a base layer made of a metal material; a heater that contacts with an inner surface of the endless belt; and a backup member that forms a nip portion together with the heater through the endless belt. The image formed on the recording medium is heated while being pinched and conveyed in the nip portion. An end surface of the base layer includes a plane region and a curved surface region. When the thickness of the base layer is t, the width of the plane region in a thickness direction of the base layer is h, and the flatness ratio H of the end surface of the base layer is defined as h/t, the flatness ratio H satisfies 50%&#x2266;H&#x2266;90%.

Image heating apparatus and endless belt used for image heating apparatus

The present invention relates to an image thermal apparatus including a flexible metallic sleeve, the inner peripheral surface of which contacts a heater. In order to provide increased durability for the sliding face of the heater, an imide resin that contains silicon nitride elementary particles is used to coat the sliding face of the heater.

Image heating apparatus including flexible metallic sleeve, and heater used for this apparatus

An image heating apparatus for heating an image formed on a recording material, the apparatus including a conveying roller for conveying a recording material, the conveying roller including a metal core and an elastic layer provided outside the metal core, wherein the metal core has, in a central portion in the longitudinal direction thereof, a straight shape area having a substantially uniform diameter along the longitudinal direction and tapered shape areas, on both sides of the straight shape area, in which a diameter gradually decreases toward ends in the longitudinal direction, and wherein the elastic layer has, in a central portion in the longitudinal direction thereof, a straight shape area having a substantially uniform diameter along the longitudinal direction and inverted crown shape areas, on both sides of the straight shape area, in which a diameter gradually increases toward ends in the longitudinal direction. This configuration allows to prevent defects in image heating while suppressing creases in the recording material.

Image heating apparatus and conveying roller for use therein

The image heating apparatus for heating a toner image formed on a recording material, includes 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, wherein the control device, in the cleaning mode, starts energizing the heater to dissipate heat in a condition that the rotatable member stops and afterward stops energizing the heater, and wherein the control device rotates the rotatable member until a part which forms a heating nip portion in a peripheral direction of the rotatable member reaches the conveying nip portion. 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

A heat fixing apparatus, in which a recording material, with an unfixed image passes through a fixing nip formed by a fixing member and a pressurizing member, has an electro-conductive member to be in contact with the recording material disposed downstream of the fixing nip with respect to the recording material conveying direction, wherein a bias voltage is applied to at least one of the fixing member and the electro-conductive member. As recording materials are consecutively fed, the bias voltage applied while the recording materials pass through the fixing nip portion is gradually decreased in accordance with the number of heated recording materials. Thus, smeared image trailing edge upon fixing is prevented from occurring, and the amount of toner adhering to the surface of the fixing member or the surface of the pressurizing member is reduced, so that image errors such as toner contamination are prevented from occurring.

Heat fixing apparatus

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.

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 forming device for forming an image onto a recording material and a fixing device for fixing the image on the recording material. The fixing device has a rotating member for conveying the recording material, and a controller for controlling the factors related to the peripheral speeds of the rotating member in accordance with the information of the peripheral speeds thereof and the size of the recording material. With the structure thus arranged, it is possible to prevent image problems from taking place due to the difference in the sheet conveying speeds between the image transfer and fixation operations.

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

An image heating device includes a heater generating heat upon electric power supply, and a film whose one surface slidably contacts the heater, and whose other surface moves together with a recording material bearing an image while contacting the recording material. The image on the recording material is heated by heat from the heater through the film. The device also includes a thermoprotector having a bimetal which mechanically changes in order to disconnect electric power supply to the heater when there is an excessive temperature rise. The bimetal of the thermoprotector contacts the heater.

Image heating device with bimetal thermoprotector

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

An image forming apparatus has an image forming unit for forming an image on a recording material, a fixing device for fixing the image on the recording material, an overlap-feed detector such as a transfer current detector for detecting an overlap-feed of the recording material conveyed to the fixing device and a set temperature controller for controlling the set temperature. The fixing device is maintained at a set temperature during an image fixing operation. The controller lowers the set temperature or stops the conveyance of the recording material when the overlap-feed detector detects the overlap feed. Accordingly, the image forming apparatus can prevent a fixing device from breaking due to an overlap-feed of a recording material.

Growing community of inventors

Kawasaki, Japan

Hiroto Hasegawa