Ricoh Printing Systems, Ltd.

Hitachi, Ltd.

Ricoh Company, Ltd.

Other

Hitachi Koki Co., Ltd.

Hitachi Printing Solutions, Ltd.

Shigeru Obata

Toshio Ogiso

Masahiro Yagi

Chikara Hiraoka

Toru Hanashima

Yoshihiro Fukuhata

Kazutaka Sato

Akitomo Kuwabara

Isao Nakajima

Shuho Yokokawa

Shunichi Oohara

Kenji Asuwa

Hidefumi Ohtsuka

Yasushi Kinoshita

Osamu Saito

Junichi Matsuno

Michihiro Watanabe

Munetoshi Zen

Tetsuya Ooba

Akira Shimizu

Hiroyuki Seki

Kazuhiro Wakamatsu

Shin Yamamoto

Yasuo Takuma

Yasuyuki Tsuji

Taisaku Seino

Tetsuya Ohba

Masaru Nakano

Kentaro Hamma

Shogo Matsumoto

Kazuo Kikuchi

Masato Miwa

Tetsuji Takegoshi

Muneyoshi Akai

Hiromitsu Fukuda

Kazuo Uno

Kazushige Oonishi

Shoji Ukei

Katsuyoshi Onose

Hiroyoshi Matsumoto

Yoji Hirose

Chiharu Kamoshida

Maya Arai

Kazuhiko Atou

Katsuhiko Kamachi

Kazuhiko Atoh

Shunjchi Oohara

Toru Ohashi

Tsuyoshi Koyama

The fixing device includes a fixing unit, a pressure unit that comes into pressure-contact with the fixing unit to form a nip, and control guides. The fixing unit includes a heat roller. The pressure unit includes a pressure belt, and a pressure pad. The pressure pad is attached to a holder and pressed by a spring through a stay, thereby bringing the pressure belt into pressure-contact with the heat roller. The control guides on both sides of the pressure pad control deformation of the pressure pad in an axial direction of the heat roller to make a nip shape uniform.

Fixing device and image forming apparatus

A low-heat loss, belt nip-type fixing device achieves good recording medium separation performance without increasing the size of the device, prevents image misalignment, and achieves a high-quality image without placing a major burden on the recording medium. This fixing device comprises a heat-fixing roller having an elastic layer and a heat source; and a pressurizing unit having an elastic member with a flat surface for pressing an endless member. The endless member conveys a recording medium, against the elastic layer. A pressurizing spring biases the elastic member toward the side of the recording medium. Biasing is carried out using the pressurizing spring such that the amount of deformation of the elastic member approaches the saturation region (maximum amount of deformation) inside a region of a nip portion, which is formed between the elastic layer of the heat-fixing roller and the endless member of pressurizing unit, and through which is passed a recording medium carrying an unfixed toner image.

Fixing device including a heating unit and a pressurizing unit that includes a rotatable endless member and image forming apparatus having the same

A pressurizing member includes an elastic member having a uniform elastic modulus of K=EA/t, where E is a Young's modulus, A is an area of the nip portion, and t is a thickness of the elastic member in the direction of application of load. A supporting member that supports the pressurizing member has an entering portion, an exit portion, and a center portion between the entering portion and the exit portion. The thickness of the center portion in a direction of application of load is larger than thicknesses of the entering portion and the exit portion in the direction of application of load so that the supporting unit has a convex portion.

A ratio of a radius of curvature of a pressure applying member with an elastic layer, which pushes an endless belt wound around an endless heating member with pressure, in a transferring direction to a radius of curvature of an outer diameter of the heating roller is set to 1.1 or more.

Fixing device and image forming apparatus using the same

A fixing device includes a fixing member of which surface is deformable, a heating unit that heats the fixing member, a pressurizing unit having an endless member and a pressurizing member. The pressurizing member includes an elastic layer and presses the endless member against the fixing member to bring the endless member into pressure contact with the fixing member. The elastic layer has an apparent hardness (ASKER-C) which is larger than that at a point where an apparent hardness starts to change rapidly with respect to a rubber thickness in a load application direction.

In a fixing apparatus including heating member having an elastic layer and a heat source and pressing member having an endless shape member and a pressing member for transporting a record medium in a cut sheet shape while being adhered with an unfixed toner image to pass a nip portion formed by the endless shape member and the heating member and fixing the unfixed toner image on the record medium, the fixing apparatus is constructed by a constitution in which a space between the toner image on the record medium and a surface of the heating member is widened immediately after the record medium is projected from an outlet of the nip portion.

Fixing apparatus and image forming apparatus including heating member

A disclosed fixing device includes: a heat roller unit having a rotatable roller having an elastic body on a surface thereof and a heating unit heating the roller; a pad disposed along a circumference of the elastic body of the heat roller; a belt member disposed on a curved surface of the pad, the belt member rotating by following a rotation of the heat roller; and a pressure member pressing the belt member to the heat roller using the pad, the fixing device causing a conveyed recording medium carrying a visualized image to pass through a space between the heat roller and the pressure member so as to fix the visualized image on the recording medium, wherein a curvature of the curved surface of the pad is changed in a central portion and end portions in an axial direction of the heat roller.

Fixing device and image forming apparatus provided with fixing device

A fixing device includes a first fixing part having a heater disposed therein, a second fixing part, disposed to oppose to the first fixing part, for pinching a recording medium to form a first nip portion, a pair of transfer rollers, disposed at a downstream side of the recording medium, for forming a second nip portion, a guide for biasing the recording medium discharged from the transfer rollers towards the first fixing part side from one of the transfers rollers, and means part for biasing the guide towards the recording medium side.

Fixing device and image forming apparatus with guide having adjustable biasing angle

An electro-photographic apparatus for conducting printing includes a fixing member fixing an unfixed toner image on a surface of a recording medium onto the recording medium. The fixing member includes a heating roller and a pressurizing member, and a mounting member on which the pressurizing member is mounted. The pressurizing member is supported by the mounting member in a substantially center part in a longitudinal direction of the pressurizing member.

Electro-photographic apparatus with a heating roller and pressurizing member

A fixing unit that is provided in an image forming device and fixes a toner image transferred to paper is constructed of two belts, belt guides each of which guides the inner periphery of each of the belts, a heating member arranged in one of the belts or heating members arranged in both of the belts, a drive roller for driving the inner periphery of the belt, wherein the belts pinch paper on both surfaces thereof by the belt guides and carry the paper. This construction can realize a fixing unit reduced in size and capable of printing images at high speeds and shortening a rise time that elapses until the fixing unit reaches a fixable temperature.

Heat fixing unit with improved belt handling

An image forming and recording apparatus, having a fixing apparatus for fixing unfixed toner image on a recording medium, wherein the fixing apparatus includes a fixing roller integrating a heater therein, an endless belt wound around the fixing roller, and three pressure members for pressing the endless belt onto the fixing roller. A pressure member located nearest to a side of entry of paper among the three pressure members is made up with a non-rotary type pressure member, and other two pressure members are made up with either one of a rotary type pressure member and the non-rotary type pressure member.

Image forming and recording apparatus with three pressure members

When initially routing a continuous web along a path, the web walks across the width of the path, and uneven tension occurs causing the web to break in some cases when printing tension is applied thereto. Further, uneven web tension is produced on the right and left of the web by excessive walk control resulting from an excessive deviation of the web from the target position of a walk controller, with the result that the web is crumpled and broken. These problems are solved by maintaining a web tension that is lower than the printing tension until the web position converges on the target position of the walk controller after loading of the web, thereby reducing the amount of correction by the walk controller and the amount of web lost in the preparatory phase before printing, with the result that excellent image quality free from crumple or breakdown is ensured.

Image forming apparatus

To stably transport an elongated web-like print paper so as not to move in the widthwise direction of the print paper, a first sensor is disposed at a first position in a paper conveying path and a second sensor at a second position downstream of the first position with respect to the paper conveying direction. Both the first and second sensors detect a position of a side edge or the print paper. A difference between the outputs from the first and second sensors is computed while taking a travel time of the edge detected by the first sensor to reach the second sensor into account. A main controller generates a drive signal based on the difference computed and controls a mechanism for moving the print paper in the widthwise direction in accordance with the drive signal.

Widthwise paper drift correction device for elongated web-like print paper

An image forming apparatus is provided in which a misregistration of an image forming-position due to a tension, acting on a continuous recording medium, and a fluctuation thereof, is corrected with a low-cost construction to provide an image of high quality. A pair of recording medium speed detection devices are provided upstream and downstream of an image forming section, respectively, and a misregistration correction amount is calculated from a detected recording medium feed speed so as to correct the image forming position.

An image recording apparatus for recording a two-color image on both surfaces of a continuous recording medium includes a toner image recording portion which has a toner carrier and transfers a toner image formed on a surface of the toner carrier onto the recording medium, a tractor for feeding the recording medium on which the toner image is transferred, and a both side fixing machine for receiving the recording medium fed by the tractor to fix the toner image transferred on the recording medium. In this image recording apparatus, guide rollers come into contact with non-printing portions on both side ends of the recording medium to apply tension to the recording medium by a spring and thereby gives a predetermined slack to the recording medium to absorb a difference in speed resulted between the tractor and the both side fixing machine.

Image recording apparatus

Growing community of inventors

Ibaraki, Japan

Shigeru Obata