Sharp Kabushiki Kaisha Corporation

Hiroshi Tachiki

Fumio Shimazu

Atsuyuki Katoh

Kouichi Yamauchi

Kiyoshi Toizumi

Hiromu Yoshimoto

Takuya Abe

Yoshie Iwakura

Masashi Hirai

Tomohiro Oikawa

Kohichi Yamauchi

Takahiko Yoshida

Toshiki Takiguchi

Yoshinobu Tateishi

Mitsuyoshi Terada

Norio Tomita

Toshio Yamanaka

Yoshikazu Harada

Masaru Tsuji

Hideshi Izumi

Yuhi Akagawa

Masanori Yamada

Keizo Fukunaga

Yoshiya Kinoshita

Takayuki Ohno

Yuji Nakagawa

Koichi Nakamura

Kenji Sugimura

Koichi Yamauchi

Kuniaki Nakano

Hideaki Kadowaki

Hirokazu Yamauchi

Kazuhiro Matsuyama

Atsushi Ide

Tadasu Taniguchi

Toshiya Mikita

Hiroyuki Murai

Fumito Mizoguchi

Yoshiaki Masuda

Yasunori Minakuchi

Yoshiteru Kikuchi

Shohtaroh Okamoto

Takashi Makiura

Kenichi Isomi

Tomohiko Fujii

Noritaka Okazaki

Kazuaki Ishikawa

Akira Sugiyama

An image forming apparatus includes a photoconductor unit that supports a photoconductor drum, a transfer roller brought into pressure contact with the photoconductor drum, a transfer unit that supports the transfer roller, a sheet guide provided between the photoconductor unit and the fixing unit, and a support holder that supports the transfer unit and the sheet guide. The support holder moves to bring the transfer unit and the sheet guide into and out of contact with the photoconductor unit and the fixing unit. The transfer unit is provided with a transfer positioning section that positions the transfer unit by coming into abutment therewith. The sheet guide is provided with a guide positioning section that positions the sheet guide by coming into abutment therewith. The transfer unit and the sheet guide are joined to each other by an engagement unit that engages the two with each other.

Image forming apparatus

A displacement mechanism for a secondary transfer unit () includes a first eccentric cam (), a second eccentric cam () and a shaft member (). The first eccentric cam () and the second eccentric cam () are in contact with either edge portion of the secondary transfer unit () in width direction of a primary transfer belt (), and rotate in phase with each other. The shaft member () supports the first eccentric cam () and the second eccentric cam (). The first eccentric cam () is configured in such a manner that any radius in a peripheral portion () is of magnitude not less than a radius at a segment of the second eccentric cam () that is in phase with a segment of the peripheral portion (). The second eccentric cam () is configured in such a manner that any radius in at least a segment of a peripheral portion () not including a press generating section () nor a separation generating section () is smaller than a radius at a segment of the first eccentric cam () that is in phase with the segment of the peripheral portion ().

Displacement mechanism for secondary transfer unit of an image forming apparatus

A secondary transfer unit stretches a transfer belt in an endless form over a driving roller, a driven roller, a transfer roller, an auxiliary roller, and a support roller therebetween. The transfer belt moves, by rotation of the driving roller, along a circulation path which passes through a transfer position. The transfer roller and the auxiliary roller press the transfer belt from the inner peripheral surface of the transfer belt toward an intermediate transfer belt in the transfer position. The transfer belt has an outer peripheral surface thereof which is pressed against the intermediate transfer belt and is roughened so that the surface roughness of the outer peripheral surface becomes 6 &#x3bc;m to 10 &#x3bc;m.

Transfer belt unit and image forming apparatus

An intermediate transfer unit includes a shaft, a joint member, an apparatus frame and a supporting member. The joint member includes a first concave portion in which a first end portion in a longitudinal direction of the shaft is fittable at a plurality of angles around a first axis of the shaft, and a first peripheral portion having a second axis that is parallel to but does not share the same straight line with the first axis. The apparatus frame has a through hole. The supporting member has a second concave portion which the first peripheral portion is attachable to and removable from at a plurality of angles around the second axis, and is insertable into and removable from the through hole in the longitudinal direction.

Belt conveyance device

An image forming apparatus according to this invention includes a first movement mechanism, a preliminary charger, and a second movement mechanism. The first movement mechanism moves a primary transfer section between a first position at which an intermediate transfer member is brought into pressure contact with a photoreceptor and a second position at which the intermediate transfer member is spaced apart from the photoreceptor. The preliminary charger is disposed in the motion direction of the intermediate transfer member between the primary transfer section and a secondary transfer section, and disposed at a predetermined position relative to the intermediate transfer member. The preliminary charger applies a charge to a toner image on the intermediate transfer member. The second movement mechanism moves the preliminary charger as the primary transfer section is moved by the first movement mechanism, while maintaining the preliminary charger at the predetermined position relative to the intermediate transfer member.

A mounting portion is configured to mount thereon a first coupler provided with a pair of engagement arms having an elastic force in a width increasing direction. The mounting portion includes a pair of support members. The pair of support members each have a support portion, an inclined portion, a first engagement portion, and a second engagement portion. A spacing between the second engagement portions is larger than a widthwise dimension of the first coupler which is taken on when the engagement arms are displaced into a position at which the widthwise dimension of the first coupler is minimized. A space allowing the first and second couplers in a state of being coupled to each other to be placed therein is provided on a downstream side of the mounting portion in a removing direction.

Structure of a component mounting portion, and functional unit

In an embodiment of the present invention, an image forming apparatus includes a transfer belt that primarily transfers a toner image formed on a photosensitive drum; a secondary transfer unit including a transfer mechanism portion that secondarily transfers the primarily transferred toner image to a paper; an optical sensor that detects a reference toner image on the transfer belt; and a shutter that protects a detection face of the optical sensor, wherein a separation/contact mechanism portion disposed so as to be brought into contact with both of the shutter and the secondary transfer unit is provided, and the separation/contact mechanism portion allows the shutter to move so as to open and allows the secondary transfer unit to move so as to separate from the transfer belt when the reference toner image is detected by the optical sensor, and allows the shutter to move so as to separate from the transfer belt when the secondary transfer unit is drawn out from an apparatus main body.

Intermediate transfer-type image forming apparatus with separation/contact mechanism

A belt transfer device according to the present invention includes an intermediate transfer belt, a transfer member, a shifter, a detector, and a controller. The transfer member primarily transfers a toner image from an image carrier to the intermediate transfer belt. The shifter reciprocates in specified opposite directions so as to shift the transfer member between a transfer position where the transfer member is in compressive contact with the inner surface of the intermediate transfer belt and a home position where the transfer member is away from the belt surface. The detector outputs a signal representing the position of the shifter. Based on the state of the signal output from the detector while the shifter is reciprocating each time in the opposite directions, the controller determines whether the tensile force of the intermediate transfer belt is proper.

Belt transfer device

As a projection extending member is arranged adjacently to a projection, a sensor Sproduces an 'ON' state output when an eccentric cam starts turning even in non-printing mode. The time from when the eccentric cam starts turning until sensor Schanges its output from 'ON' to &#x201c;OFF&#x201d; becomes longer when a new intermediate transfer belt unit is used than when a used intermediate transfer belt unit is used. The length of this time is measured so as to detect whether the intermediate transfer belt unit is brand-new or old.

Transfer device including detecting mechanism for detecting replacement belt unit and image forming apparatus using the same

A transfer unit includes: an intermediate transfer belt that (i) holds a toner image that has been transferred from a photoreceptor drum and (ii) moves a surface holding the toner image; and a secondary transfer belt that comes into contact with the intermediate transfer belt. The transfer unit (i) transfers the toner image from the intermediate transfer belt to a sheet conveyed to the secondary transfer part and (ii) includes a cleaning unit that removes and collects toner from the surface of the intermediate transfer belt. The transfer unit also includes a power source for sequentially applying, to the secondary transfer belt, (i) a first voltage for generating an electric field that transfers normally-charged toner from the secondary transfer belt to the intermediate transfer belt and (ii) a second voltage for generating an electric field that transfers oppositely-charged toner from the secondary transfer belt to the intermediate transfer belt.

Transfer unit, transfer method, and image forming apparatus

Providing a simply-arranged detaching/attaching mechanism and image forming device which allow a transfer supporter device to be detached/attached through a space formed by opening an outer covering, the device includes photosensitive drums, detachable/attachable transfer belt unit, and rail members supporting a transfer belt unit. Each of the rail members includes a rail groove guiding the transfer belt unit, notch and positioning hole determining the position of the transfer belt unit when the belt is in contact with the photosensitive drums, and notch and convex section determining the position of the transfer belt unit when the belt is detached from the photosensitive drums. The transfer belt unit support with respect to the main body of the image forming device, performed by the rail members, is released in response to the action of opening the side cover, so that the transfer belt unit is in a free state.

Detaching/attaching mechanism and image forming device

An armored unit includes a side cover and a guide member. When sheet jam operation is carried out, a fixing unit is pulled out with the armored unit, and then is pushed to the rear side. This operation unlocks the lock member provided in the guide member, and a shoulder screw moves in a guide hole. Thus, the fixing unit is moved from the pulled out position toward the rear side and toward the main body of image forming device to be shifted to a receding position. On this account, it is possible to provide an image forming device ensuring sufficient space for removing a jammed sheet by hand with a small opening space.

Image forming device with movable processing unit

A transfer belt device includes an endless transfer belt that is tightly stretched by a plurality of rollers and forms a transport path where a recording medium or a developer image is transported facing a monochrome image bearing member and a plurality of color image bearing members arranged in parallel along a fixed direction. In the apparatus, a first transfer unit having a first linking member in which a monochrome-image transfer member is supported that transfers a developer image formed on the monochrome image bearing member onto a recording medium or an outer peripheral surface of the belt, and a second transfer unit having a second linking member in which a plurality of color-image transfer members are supported that transfer developer images formed on the respective color image bearing members onto a recording medium or an outer peripheral surface of the belt, are linked via the first and second linking members.

Transfer belt device and image forming apparatus

A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.

Transfer device and image forming apparatus

A plurality of photosensitive drums are disposed in a sheet transport direction so as to be in contact with a transfer belt and a transfer voltage for transferring toner images on the photosensitive drums onto a sheet transported by the transfer belt is applied thereto. A sensor for sensing a temperature or humidity in the working atmosphere of the image forming apparatus is provided; when a jam occurs, sheet transportation is ceased at a first stage to thereby enable the sheet in the jam to be removed; at a second stage subsequent thereto, transportation of the sheet is restarted; and the transfer voltage applied onto the transfer belt is controlled based on a measurement result of the sensor.

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Yamatokoriyama, Japan

Hiroshi Tachiki