Ricoh Company, Ltd.

Katsuhiro Echigo

Shigeo Kurotaka

Hisashi Kikuchi

Atsushi Nakafuji

Toshihiko Baba

Takashi Fujita

Yukimichi Someya

Hiroyuki Kunii

Tsuneo Kurotori

Manabu Mochizuki

Jun Yura

Hirokazu Ikenoue

Ichiro Tsuruoka

Kenzo Ariyama

Kohji Ue

Mayumi Miyao

Kenji Kojima

Hideki Kosugi

Hajime Oyama

Makoto Obu

Takahiro Tamiya

Hidetoshi Yano

Yasuhiro Kawashima

Kunio Hibi

Fumio Kishi

Kiyoshi Ohshima

Itsuo Ikeda

Yasuo Kawada

Mitsuaki Urakawa

Hidenori Sakai

Hisamitsu Mizuno

Hiroshi Tanabe

Minoru Iwamoto

Hiroaki Takenouchi

Masami Tomita

Shigeru Watanabe

Nobuo Kasahara

Kazuhito Kishi

Shinichi Kawahara

Hiromitsu Takagaki

Sadayuki Iwai

Shigeru Yoshiki

Setsuo Soga

Hiroyuki Shibaki

Takashi Kawashima

Nobuaki Tomidokoro

Hideaki Matsui

Hirohmi Tamura

Eriko Konno

Ichirio Tsuruoka

Yasuhiko Taguchi

An image forming apparatus including an endless intermediate transfer member stretched over a plurality of rollers; a first biasing member; a secondary transfer roller to be pressed against a surface of the intermediate transfer member by the first biasing member; an opposed roller disposed opposite the secondary transfer roller to thus form a secondary transfer nip at which the toner image carried on the intermediate transfer member is transferred onto a recording medium; and a second biasing member to bias the opposed roller. The secondary transfer roller and the opposed roller are movable along a line connecting respective axes of the rollers and a pressure Fapplied by the first biasing member to the secondary transfer roller at the secondary transfer nip is greater than a pressure Fapplied to the opposed roller by the second biasing member at the secondary transfer nip.

Image forming apparatus including a secondary transfer nip formed with a movable roller

A fixing apparatus includes a fixing member to be heated and a pressure-contacting member for pressure contacting the fixing member. The fixing apparatus directs and conveys a recording member through a nip formed between the fixing member and pressure applying member in such a manner that a toner image carried on a recording member contacts the fixing member in order to be fixed thereto with heat and pressure. The fixing apparatus is configured to direct a tip margin of the recording member toward the pressure applying member across a virtual linear extension line drawn from a downstream end to upstream end of the nip when only the tip margin exits from the nip. A fixing member side separation device may be separately provided from the surface of the fixing apparatus so as to separate the recording member exiting from the nip. A gap formed between the downstream end of the nip and the tip of the fixing member side separation device is set smaller than the width of the tip margin.

Sheet wrapping avoidable fixing apparatus and image forming apparatus

A transfer device for use in an image forming apparatus includes at least two belt members constituting a secondary nip portion therebetween. The transfer device electrostatically transfers a toner image from one of the belt members onto a recording medium when the recording medium passes through the secondary nip portion. The transfer device includes a mechanism that supports the belt members such that the secondary nip portion is substantially linear; and a bias applying member that applies a secondary transfer bias at a substantially center portion of the secondary nip portion.

Transfer device and image forming apparatus

An exit blade is arranged on a downstream side of a transfer nip formed between a photosensitive element and a primary transfer roller, with an intermediate transfer belt being put therebetween, and brought into contact with an internal surface of the intermediate transfer belt. A neutralizing bias of the same polarity as that of the toner is applied to the exit blade, rather than a primary transfer bias voltage.

Image forming apparatus having a neutralizing member of determined resistivity

An intermediate transfer belt and a photosensitive member form a transfer nip. An electrode is arranged close to an inner surface of the intermediate transfer belt in a portion on an upstream side of a direction of endless movement of the intermediate transfer belt with respect to a downstream-side exit of the transfer nip and on a downstream side of the direction of endless movement with respect to a position at which a transfer roller charges the intermediate transfer belt. A voltage of same polarity as the polarity of a toner is applied to the electrode, so that there is no movement of an electric charge between the electrode and the intermediate transfer belt.

Image forming apparatus

The fixing unit satisfies following three conditions. That is, (1) 2.4&#xd7;10&#xd7;d/(TC&#xd7;t)&#x3c;T, where d is a thickness of the unfixed toner layer in meters, TC is a thermal conductivity of toner in W/mK, and t is the fixing time in seconds; (2) a temperature Tof a topmost layer of the toner layer is not greater than the minimum temperature Tat which the hot offset of the surface of the first fixing member occurs when the fixing time is set to 1 seconds; and (3) a temperature Tof a bottommost layer of the toner layer that is in contact with the recording medium is not less than the lower limit temperature Tfor fixing of the surface of the first fixing member when the fixing time is set to 1 second.

Image forming apparatus with toner image fixing unit, and the fixing method thereof

An image forming apparatus, includes an image forming mechanism configured to form an image, and a fixing unit configured to fix a toner image formed on a recording medium. The fixing unit includes a fixing device having a first endless moving member configured to rotate, and a second endless moving member configured to rotate to form a nip area together with the first endless moving member to fix, at the nip area, a toner image disposed on the recording medium onto the recording medium with heat and pressure, the second endless moving member including a surface layer having a universal hardness HU and a maximum nip surface pressure P each within a predetermined range.

Image forming method and apparatus for fixing an image

An image forming apparatus includes at least one image forming unit, a primary transfer belt, and a secondary transferer. The image forming unit includes an image carrier and a primary transfer bias applicator. The secondary transferer includes a secondary transfer nip, a secondary transfer bias applicator, and a facing member facing the second transfer bias applicator. The secondary transfer bias applicator forms a secondary transfer electric field. The image forming apparatus further includes a bias applicator, a contact start site, and an electrode. The bias applicator applies a bias voltage having a same polarity as the normal charge polarity of the toner to the primary transfer belt, downstream of the primary transfer bias applicator. The recording medium starts to contact the toner image at the contact start site, located upstream of the secondary transfer nip, where the electrode forms an electric field.

A fixing member heat bonds a toner on a recording material. The fixing member includes a releasing layer, a layer of elastic material, below the releasing layer, and a layer of adiabatic and hygroscopic material, below the layer of elastic material. The layer of elastic material includes a layer of electrically conducting material to pass electric currents, an adiabatic, elastic, and hydrophobic material, and a porous material to the release of the moisture absorbed by the layer of adiabatic and hygroscopic material.

Fixing member, fixing device, and image forming apparatus

A fixing device for fixing image information on a recording medium passing a nip of the present invention includes a rotatable member for transferring and conveying a non-fixed image, a first heating means for heating an image present on the rotatable member and a rotatable pressing member forming a nip in combination with the rotatable member. A heat pipe extends in parallel to the axis of the rotatable member. A radiating member is positioned at one end of the heat pipe while a heating member is positioned at the other end of the heat pipe.

Fixing device and image forming apparatus using the same

A fixing device including a magnetic field generating device to generate a magnetic field, a fixing member to heat a recording material by heat generated in a first recording material passing area having a first width on the fixing member by electromagnetic induction heat generation by the magnetic field formed by the magnetic field generating device, a pressing member to form a nip portion where the pressing member and the fixing member press against each other to fix an unfixed image on the recording material, and at least one radiation heating device configured to heat a second recording material passing area having a second width.

Fixing device with temperature control

A fixing belt is heated by electromagnetic induction. The fixing belt has a heat generating layer that has a thickness not greater than 40 &#x3bc;m and a releasing layer that has a thickness not less than 10 &#x3bc;m. A toner that includes at least a binder resin, a colorant, and a mold releasing agent, and has a glass transition temperature in a range of 35&#xb0; C. to 50&#xb0; C. and an outflow-start temperature in a range of 80&#xb0; C. to 110&#xb0; C., is used.

Fixing unit and image forming apparatus providing a quick start-up and reduction in energy consumption

A transfer-fixing unit for use in an image forming apparatus having an intermediate transfer member and a transfer-fixing unit, which includes a pressure member and a transfer-fixing member. The intermediate transfer member receives a toner image thereon. The transfer-fixing member has a deformable surface layer thereon, and directly receives the toner image from the intermediate transfer member, and transfers and fixes the toner image to a recording medium while deforming the surface layer in response to surface irregularities of the recording medium. The transfer-fixing member forms a nip portion with the pressure member and presses the recording medium at the nip portion when the recording medium passes through the nip portion with a nip time.

Transfer-fixing unit with a surface layer of predefined hardness for use in an image forming apparatus

A fixing device containing at least one fixing member configured to fix a toner image on a transfer material, which includes a first substrate and a pressing member configured to form a nip with the at least one fixing member, which includes a second substrate, and a heater. At least one of the at least one fixing member and the pressing member further contains a heat insulating layer overlying the first or second substrate.

Fixing device, image forming apparatus using the fixing device, and heat insulating member

Growing community of inventors

Saitama, Japan

Katsuhiro Echigo