Sharp Kabushiki Kaisha Corporation

Sharp Labushiki Kaisha

Yoshiaki Masuda

Hirokazu Yamauchi

Hiroshi Kida

Toshiki Takiguchi

Takashi Kubo

Hiroyuki Murai

Hidetoshi Kaneko

Fumio Shimazu

Masashi Hirai

Hideo Matsuda

Toshiki Ohgita

Tadasu Taniguchi

Tokiyuki Okano

Kazunori Soda

Kazunori Iwasa

Koichi Matsumoto

Tomiyuki Ishikawa

Toshiaki Kagawa

Hiroshi Ishii

Susumu Murakami

Kuniaki Nakano

Yoshie Iwakura

Nobuyuki Ueda

Kazuhiro Matsuyama

Yasutaka Maeda

Hiroshi Tachiki

Mikio Kakui

Tatsuya Inoue

Tomomi Tanaka

Shinichi Takeda

Yasuhiro Ono

Masato Tokishige

Noriaki Taguchi

Hideki Ohnishi

Kiyoshi Inamoto

Hiroshi Kawamoto

Koichi Moriyama

Atsushi Kurimoto

Kazuaki Ishikawa

Yoko Sawa

Ichiro Terada

Syuichi Yoshinaka

Noriyuki Sakurai

An image forming apparatus includes a transfer belt unit which has an intermediate transfer belt for supporting toner images and primary transfer rollers for pressing the intermediate transfer belt against corresponding photoreceptor drums and moves the intermediate transfer belt along the surface of each photoreceptor drum to transfer the toner images to the intermediate transfer belt. The intermediate transfer belt is formed so as to be 30 &#x3bc;m to 50 &#x3bc;m in average thickness, each primary transfer roller is arranged at a position, along the moving direction of the intermediate transfer belt, which is deviated downstream with respect to the moving direction from the position where the intermediate transfer belt is in contact with the photoreceptor and which is projected toward the photoreceptor drum side so as to press the intermediate transfer belt against photoreceptor with a nip pressure ranging from 10 gf/cmto 40 gf/cm.

Transfer belt unit and image forming apparatus using the same

Ions generated by the ion generating section are discharged from a paper sheet conveyer belt nozzle and an intermediate transfer belt nozzle, so that (i) a toner image transferred from a photosensitive drum onto an intermediate transfer belt and having yet to be transferred from the intermediate transfer belt onto a recording paper sheet and (ii) a paper sheet conveyer belt are charged. This makes it possible to more appropriately transfer a toner image onto a recording paper sheet from a photosensitive drum in an image forming apparatus, including a conveyer belt for conveying a recording paper sheet, in which a toner image formed on an image carrier is transferred onto an intermediate transfer body and the toner image is transferred from the intermediate transfer body onto a recording material; and to simultaneously prevent an increase in size of the image forming apparatus.

Image forming apparatus with ion generator

The present invention is made to provide a pretransfer charging device, which allows (i) reduction of generation of discharge products such as ozone and nitroxide, (ii) excellent uniform charging, (iii) continuous stable charging for a long period of time, and (iv) restraint of distortion of a toner image. The pretransfer charging device includes (i) ion generation needles each provided face to face with an image carrier such as a photoconductor drum or an intermediating transfer belt, and (ii) a high-voltage power supply for applying a negative voltage to each of the ion generation needles. The voltage to be applied from the high-voltage power supply is not less than an ion production threshold voltage but is less than a corona discharge threshold voltage. With this, no corona discharge occurs but negative ions can be generated. This makes it possible to solve various problems caused due to the corona discharge.

Pretransfer charging device and image forming apparatus including same

A combined resistance R=Vt/I(MO) of a transfer belt () and a recording sheet obtained when a transfer current I(&#x3bc;A) passes through the transfer belt () and the recording sheet upon application of a first transfer bias voltage Vt(V) to a transfer roller () from a high-voltage power source () and a combined resistance R=Vt/I(MO) of the transfer belt () and the recording sheet obtained when a transfer current I(&#x3bc;A) passes through the transfer belt () and the recording sheet upon application of a second transfer bias voltage Vt(V) to the transfer roller () from the high-voltage power source (), are established to have the relationship: R/R=7 ?(I)therebetween.

Belt transfer apparatus and image forming device

Transfer roller(s) is/are such that either end thereof is formed from fibrous electrically conductive component(s) and such that cylindrical portion(s) in central region(s) is/are, for example, formed from metal roller-like structure(s), either fibrous electrically conductive component outer end being arranged so as to extend somewhat beyond either transfer/transport belt side. Furthermore, outside diameter(s) approximated by tips of respective individual fiber(s) of fibrous electrically conductive component(s) is/are somewhat larger than diameter(s) of metal roller-like structure(s). This makes it possible for electric field(s) to be applied, and for charging to occur, along the full width(s) of transfer/transport belt(s).

Image forming apparatus and transfer apparatus employing endless belt

An embodiment of a screw conveyor includes a rotating shaft and a conveying blade helically formed around and loosely coupled with the rotating shaft. One or both of two edges of the conveying blade is/are only fixed to the rotating shaft, and a gap is provided between the rotating shaft and the conveying blade. Thereby, the conveying blade can be vibrated in a center axis direction of the rotating shaft by rotation of the rotating shaft and conveyed waste developer.

Screw conveyor and developer conveying mechanism

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

An image forming apparatus includes an endless belt stretched over a plurality of rollers. The apparatus also includes a potential detecting device for detecting a potential of the endless belt. The detecting device is positioned downstream, along a sheet transport path, of a transfer position where the belt has direct contact with the image bearing member. The apparatus further includes a transferring member for transferring a toner image formed on the image bearing member to a sheet. An image forming process is halted when the potential detecting device does not detect a change in potential caused by presence of a sheet on the endless belt.

Image forming apparatus

A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations.

Image device with control members for rollers

A first control member is disposed in a drum shaft away from a photoconductive drum, and a second control member is disposed in a roller shaft away from a transfer roller. The first and second control members abut on each other at their circumferential surfaces. This helps reduce an amount of displacement resulting from an impact caused by insertion of a recording paper sheet in between the photoconductive drum and the transfer roller, and thereby reduce vibrations in the photoconductive drum. Consequently, a toner image formed on the photoconductive drum and an unfixed toner image transferred onto the recording paper sheet are not affected by vibrations, so that a high-quality image is obtained that is free from blurriness or irregularities.

An object of the invention is to convey a transfer material properly and securely in a simple structure even where space allowance is limited. An image forming apparatus has a photoconductive body and a transfer device composed of a transfer roller. After a developer image formed on the photoconductive body is electrostatically transferred onto a sheet by the transfer roller, a rear end of the sheet having passed through opposed regions of the transfer roller and the photoconductive body is, by a guiding roller arranged at a downstream side of the opposed portions along a sheet conveying path, guided in conveyance from a non-transferred surface of the transfer material so that it is kept out of contact with the transfer roller.

Image forming apparatus with transfer material guide

It is an object of the present invention to provide a laser recording apparatus wherein problems such as difficulty in maintenance and effects of shock owing to the laser recording unit of a vertically divided type laser recording apparatus being provided as a single unit, are solved. This laser recording apparatus comprises: a first main unit; a second main unit rotatably supported to the first main unit by a predetermined fulcrum, so as to enable opening and closing; wherein the first main unit is provided with a first unit having optical means, laser beam emitting means, and laser beam detecting means, and wherein the second main unit is provided with a second unit having laser scanning means.

Vertically opening laser recording apparatus

A laser recording apparatus with a laser recording unit which is movable while held horizontal at all times. The laser recording apparatus is constructed of a first frame including the bottom section of the apparatus and a second frame supported by the first frame in a manner which allows pivotable rotation of the second frame for opening the apparatus, wherein a laser recording unit including laser scanning means is supported by the second frame on the rotation fulcrum, and the laser scanning means is held horizontal to the bottom section of the apparatus before, during and after release of the second frame from the first frame.

Laser recording apparatus which maintains the laser recording unit in a

An electrophotographic apparatus is provided with a fixing device having the first through third fixing rollers for forming the first fixing section by contacting the first and second fixing rollers as well as forming the second fixing section by contacting the second and third fixing rollers, the first fixing section being temperature-adjusted in relation to a first copying mode, the second fixing section being temperature-adjusted in relation to a second copying mode. Either the first or second fixing section is temperature-adjusted according to the order of priority in such a manner that after the completion of the temperature adjustments, temperature adjustments with respect to the other fixing section is successively carried out.

Electrophotographic apparatus having two fixing sections and control

A copying machine as an example of electrophotographic printing machines is composed of a main body which permits both black-and-white copying and full color copying, and a reverse and retransport unit provided under the main body, for reversing and retransporting a sheet after being copied on one surface thereof to the main body. The main body has a fixing means including upper and lower fixing portions formed between three heat rollers. The lower fixing portion placed closer to the reverse and retransport unit is associated with the black-and-white copying, and the upper fixing portion is associated with the full color copying. Upper and lower discharge transport paths for discharging the sheet out of the device are provided so as to respectively extend from the upper and lower fixing portions. Further, a retransport path is provided so as to extend from the lower fixing portion. Since the above three paths are provided without having any crossing point, the structure of the paths is simplified. Furthermore, when carrying out a black-and-white copying on one surface of the sheet and a color copying on the other surface, the black-and-white copying is carried out first, thereby eliminating the problem of the sheet being stuck in the device.

Growing community of inventors

Nara, Japan

Yoshiaki Masuda