Sharp Kabushiki Kaisha Corporation

Fumio Shimazu

Hiroshi Tachiki

Yoshie Iwakura

Kiyoshi Toizumi

Kouichi Yamauchi

Hiromu Yoshimoto

Takuya Abe

Atsuyuki Katoh

Tomohiro Oikawa

Masashi Hirai

Hideki Ohnishi

Hideo Yamasa

Toshiki Takiguchi

Hiroyuki Murai

Kohichi Yamauchi

Noritaka Okazaki

Seiichi Yoshida

Hirokazu Yamauchi

Yoshinobu Tateishi

Shirou Wakahara

Eiichi Kido

Yuhi Akagawa

Yoshiaki Masuda

Mitsuyoshi Terada

Keizo Fukunaga

Takayuki Ohno

Osamu Nakayama

Koichi Inui

Yuji Nakagawa

Yoshiharu Ueki

Yuuhi Yui

Syoichiro Yoshiura

Atsushi Ueda

Toshio Yamanaka

Yasuhiro Takai

Katsuhiro Nagayama

Akira Tamagaki

Hideaki Hagihara

Takasumi Wada

Hidekazu Sakagami

Hirokazu Tanaka

Yukikazu Kamei

Kouichi Irihara

Toshihiko Takaya

Masao Narumiya

Yoshinobu Umetani

Koichi Nakamura

Tsuyoshi Takeno

Yoko Sawa

An image transfer device includes an image transfer electrode roller which is disposed face to face with a photosensitive drum with a printing sheet passing between the image transfer electrode roller and the photosensitive drum. The image transfer device is structured such that the image transfer electrode roller can be shifted back and forth along a transport direction of the printing sheet. A voltage is applied to the image transfer electrode roller to create an image transfer electric field between the image transfer electrode roller and the photosensitive drum for transferring a toner image formed on the photosensitive drum onto the printing sheet. The image transfer electrode roller is brought to one of different positions along a transport direction of the printing sheet selected according to information on properties of the printing sheet and transfers the toner image onto the printing sheet at that position.

Image transfer 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

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

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.

Image forming apparatus

A junction/disjunction unit of a multicolored image forming apparatus joints/disjoints a transfer material holder with/from an image holder, to switch over between a monochromatic image forming mode which uses a specific image forming unit and a multicolored image forming mode which uses a plurality of image forming units. For switching the image forming mode, a driving unit for driving the junction/disjunction unit also drives an auger provided for conveying toner, which has been recovered by a transfer material holder cleaning unit for recovering toner remaining on the transfer material holder, into a recovery container. Accordingly, a driving force outputted from the driving unit can be effectively utilized, and thereby good cost performance can be realized.

Multicolored image forming apparatus for forming multicolored and monochromatic images

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 a transport distance of the sheet is controlled based on a printing ratio of an image formed on the sheet.

In an image forming apparatus including a transfer and transport belt suspended between a plurality of rollers, an image forming section for forming a pattern image on the transfer and transport belt, and a pattern image detecting sensor for detecting the pattern image, the pattern image detecting sensor is disposed so as to detect the surface of a suspended segment, of the transfer and transport belt, suspended between the rollers, and a back surface contact member that is in contact with a back surface of a detection area where the pattern image detecting sensor detects the pattern image on the surface of the transfer and transport belt is provided so as to render the detection area flat and stable. This can provide an image forming apparatus incorporating a pattern image detecting means having a simple arrangement and a capability to surely detect the pattern image in a precise and stable manner.

An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes a member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner. The image forming apparatus further includes a charge control mechanism for controlling the amount of charges on the photosensitive drum. In addition the photosensitive drum has a voltage applying mechanism for applying a voltage to the internal surface of the drum.

An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes an upstream member or layer on the electrode member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner.

Image forming apparatus having transfer drum with transfer paper charging member

An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. A nip time changing controller changes the amount of time that a transfer sheet is in the nip between the transfer drum and the grounded conductive electrode member.

Image forming apparatus with nip time changing device

An image forming apparatus in which each test image formed in a plurality of image forming sections is transferred onto a transfer carrier belt by transfer means respectively provided corresponding to the plurality of image forming sections, and the transfer state is detected to control the image forming conditions, wherein the transfer condition of the respective transfer means is different when the test image is transferred onto the transfer medium and when the test images already formed and transferred in other image forming sections pass through the transfer means.

An idle roller on which a dielectric belt is wound is made up of a metal such as aluminum etc., and is used as a charging device. A voltage is applied to this idle roller from a d.c. power source. A sheet of paper is made to pass into and between this grounded idle roller (grounded via the dielectric belt) and the metal roller so that the paper is electrostatically attracted to the dielectric belt. The same d.c. power source which applies a d.c. voltage to the idle roller is connected to a multiple number of transfer rollers so as apply the same d.c. voltage to these transfer rollers.

Roller/belt type multiple color image transfer apparatus including

An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes a member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner. The image forming apparatus further includes a mechanism for removing the charges on the surface of the transfer drum via a bias switching device and a cleaning device for cleaning the surface of the transfer drum so as to eliminate defects in a transferred image, thereby upgrading the quality of a resulting image. The cleaning device may be a blade having a particular engagement crossover between the blade and transfer drum.

Image forming apparatus having transfer roller with charge-removing and

A sheet conveyance guide is configured of separation claws for separating the paper from a conveyer and transfer belt and a movable sheet guide for guiding the paper to a fixer entrance sheet guide. The separation claws are arranged on the upstream side of the movable sheet guide. The movable sheet guide is rotatable about a pivot shaft with its distal end abutted by gravity upon the upstream end part of the fixer entrance sheet guide. The separation claws and movable sheet guide are axially supported so as to rotate on pivots. The sheet conveyance guide moves together with the vertical movement of the conveyer and transfer belt while the abutment point of the separation claws upon the conveyer and transfer belt moves to the appropriate position.

Sheet conveying system

Growing community of inventors

Nara, Japan

Fumio Shimazu