Ricoh Company, Ltd.

Kunihiko Tomita

Naoki Iwata

Satoshi Muramatsu

Shigeru Watanabe

Hiroshi Yokoyama

Koji Suzuki

Akiyasu Amita

Hideaki Mochimaru

Hiroyuki Kunii

Yasukuni Omata

Hisao Murayama

Norimasa Sohmiya

Chiemi Kaneko

Hiromasa Takagi

Yukimichi Someya

Koji Ozaki

Misaki Shimizu

Hachiro Tosaka

Fuchio Takeda

A fixing device includes a first roller, a second roller, an endless rotary belt, a third roller, a heater, a belt cooler, and an upstream guide member. The second roller is disposed parallel to the first roller. The endless rotary belt is looped for rotation around the first and second rollers. The third roller is disposed opposite the first roller via the belt. The heater is positioned adjacent to the belt to heat the belt. The first and third rollers press against each other via the belt to form a nip therebetween. The belt cooler is disposed inside the loop of the belt downstream from the first roller and upstream from the second roller for cooling the belt. The belt cooler has a convex contact surface. The upstream guide member is disposed inside the loop of the belt upstream from the contact surface to guide the belt.

Glossing device, fixing device, and image forming apparatus incorporating same

A fixing device includes a fuser member, a stripper member, an endless rotary belt, a heater, a pressure member, and a belt cooler. The stripper member is disposed parallel to the fuser member. The endless rotary belt is looped for rotation around the fuser member and the stripper member in a longitudinal, conveyance direction of the belt. The heater is disposed adjacent to the belt to heat the belt. The pressure member is disposed opposite the fuser member via the belt. The fuser member and the pressure member press against each other via the belt to form a fixing nip therebetween. The recording medium after passage through the nip remains in contact with the belt as the belt moves from the fuser member toward the stripper member, and separates from the belt as the belt passes around the stripper member.

Fixing device and image forming apparatus incorporating same

A glossing device includes a heater member, a stripper member, an endless rotary belt, a pressure member, and a belt cooler. The heater member is subjected to heating. The stripper member is disposed parallel to the heater member. The endless rotary belt is looped for rotation around the heater member and the stripper member in a longitudinal, conveyance direction of the belt. The pressure member is disposed opposite the heater member via the belt. The heater member and the pressure member press against each other via the belt to form a glossing nip therebetween. The recording medium after passage through the nip remains in contact with the belt as the belt moves from the heater member toward the stripper member, and separates from the belt as the belt passes around the stripper member. The belt cooler is disposed adjacent to the belt to cool the belt.

Glossing device and image forming apparatus incorporating same

A glossing device includes a first roller, a second roller, an endless rotary belt, a third roller, a heater, a belt cooler, and a suction mechanism. The second roller is disposed parallel to the first roller. The endless rotary belt is looped for rotation around the first and second rollers. The third roller is disposed opposite the first roller via the belt. The heater is disposed adjacent to the belt to heat the belt. The first and third rollers press against each other via the belt to form a nip therebetween. The belt cooler is disposed inside the loop of the belt downstream from the first roller and upstream from the second roller for cooling the belt. The belt cooler includes at least two mutually spaced cooling elements that together form a gapped contact surface for establishing thermal contact with the belt.

A belt-fixing device to fix a toner image on a sheet includes an endless belt, a first roller disposed inside the endless belt, a second roller disposed in contact with the first roller via the endless belt, forming a fixing nip therebetween through which a recording medium passes, and a ring shape edge for controlling movement of the belt in an axial direction, provided on an inner surface of the endless belt. The ring shape edge is positioned between the first roller and the second roller.

In a fixing device, a first roller and a first fixing member are provided inside a loop formed by a first belt. A pressing member is pressed against the first roller and the first fixing member via the first belt. The first roller includes at least two enlarged radius portions of enlarged radius arranged axially along the first roller, at least one reduced radius portion of reduced radius sandwiched between the adjacent two enlarged radius portions in an axial direction of the first roller, and a concave portion formed by the reduced radius portion and the adjacent two enlarged radius portions sandwiching the reduced radius portion. The first fixing member is interdigitated with the first roller with play between the first fixing member and the first roller.

Fixing device and image forming apparatus using interdigitated rollers

An energy-saving fixing apparatus for use in image formation apparatuses such as a copying machine is disclosed. A recording medium is sandwiched by a pair of belts, having belt tension between 0.001 and 5.4N/mm, for a period between 50 and 1000 ms. The recording medium is pressurized at pressure between 0.007 and 2.7 Ns/mm by a nip constituted by a heating roller and a pressurizing roller. The recording medium is conveyed with its toner image carrying side being adhered to one of the belts without being cooled.

Fixing method, a fixing apparatus, an image formation method, and an image formation apparatus

An image fixing apparatus having a linear heating body with an endless belt entrained around thereon, using an electrical power supply to provide pulsating power to the linear heating body. Additionally, a pressure body interposes the subject to be fixed containing an image on the endless belt, and the image is heated by the linear heating body through the endless belt. The subject is thereafter cooled and removed from the endless belt. The image is formed by using a toner containing a binder which contains a resin as a main component. Either the softening point or the melting point of the toner is between 50&#xb0; C. to 160&#xb0; C., and the viscosity of the toner is between 10 to 10centi-poise at a temperature greater than either the softening point or the melting point of the toner.

Image fixing apparatus using pulsating power for heating

A fixing device includes a pressure belt that holds a recording medium by electrostatic force and carries the recording medium. The recording medium has a toner image on a surface that is not in contact with the endless pressure belt. A fixing belt fixes the toner image on the recording medium that is held by the pressure belt.

Fixing device and image forming apparatus for holding a recording medium by electrostatic force

An oilless toner including at least (A) a cyclic olefin resin; (B) a resin having one or more carbon-carbon double bonds therein; and (C) a wax.

Oilless toner

An image forming method begins with a first image transfer step for thermally transferring a first toner image from a first image carrier to a second image carrier contacting it. Subsequently, in a second image transfer step, the first toner image carried on the second image carrier and a second toner image newly formed on the first image carrier are thermally transferred to opposite sides of a recording medium substantially at the same time. Higher image transfer temperature is assigned to the second image transfer step than to the first image transfer step. An impurity collecting device is associated with a pair of registration rollers which stop the recording medium for a moment to thereby synchronize the recording medium to the toner image.

Image forming apparatus and an impurity collecting device associated with registration rollers

The object of the present invention is to provide an image fixing apparatus which enables achieving saving of energy in fixing by controlling the temperature of a heater to fix a toner image on a recording medium, an image forming apparatus having the image fixing apparatus therein, and an image forming process using the same. To achieve the object, there is provided an image fixing apparatus which includes a heater having a heat source to generate heat; a fixing belt which moves in a direction to which a recording medium is transported in a state where the belt comes into contact with the heater; and a pressing portion which presses the transported recording medium with a toner image carried thereon on an area of the fixing belt which comes into contact with the heater, and is characterized in that the contact surface of the heater which comes into contact with the fixing belt has a smoothly formed convex toward the side which comes into contact with the fixing belt with a curvature radius of 200 mm to 100,000 mm, and an amount of contact time between the fixing belt and the recording medium is 20 msec. or more.

Image fixing apparatus, and, image forming apparatus having the same, and image forming process

An image transferring device of the present invention includes a first and a second intermediate image transfer body whose surfaces endlessly move while forming a nip in contact with each other. When a sheet nipped by the nip is being conveyed toward a side downstream of the nip in the direction in which the above surfaces move, a first toner image transferred from an image carrier to the second intermediate image transfer body via the first intermediate image transfer body beforehand is transferred to one side of the sheet. At the same time, a second toner image transferred from the image carrier to the first image transfer body beforehand is transferred to the other side of the sheet. One of the two intermediate image transfer bodies is less deformable than the other intermediate image transfer body in the direction of thickness.

Method, system and apparatus for transferring toner images to both sides of a recording medium

An image forming method of the present invention begins with a first image transfer step for thermally transferring a first toner image from a first image carrier to a second image carrier contacting it. Subsequently, in a second image transfer step, the first toner image carried on the second image carrier and a second toner image newly formed on the first image carrier are thermally transferred to opposite sides of a recording medium substantially at the same time. Higher image transfer temperature is assigned to the second image transfer step than to the first image transfer step. Additionally, the second image carrier has a greater roughness than the first image carrier.

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Kanagawa, Japan

Kunihiko Tomita