Abstract: An image forming apparatus is constituted so as to be equipped with transfer apparatus(es) having transfer roller(s) electrostatically transferring development image(s) from photosensitive drum(s) to transfer medium/media, and so as to be provided with transfer medium guide unit disposed downstream in transfer medium transport path(s) from location(s) at which photosensitive drum(s) oppose transfer roller(s), and such that transfer medium guide location(s) of transfer medium guide means is/are variable.

Abstract: A paper separator may be equipped with plurality of paper-separating fingers for separating sheet(s) of paper for image formation and abutting and/or backed off from photosensitive body or bodies, paper separator optionally comprising finger body or bodies capable of abutting photosensitive body or bodies; spur(s)—capable of touching so as to guide sheet(s) of paper for image formation which has or have separated from photosensitive body or bodies; and/or support component(s) pivotably supporting paper-separating finger(s) so as to impart restoring force(s) thereto urging paper-separating finger(s) to under the force(s) of its or their own weight(s) bring finger body or bodies into abutting engagement with photosensitive body or bodies, and so as to, when spur(s) is or are touching sheet(s) of paper for image formation, cause finger body or bodies to at least partially overcome restoring force(s) produced by weight(s) of paper-separating finger(s) or portion(s) thereof and back off from photosensitive body or

Abstract: A transfer device is provided including an intermediate transfer belt and transfer rollers associated with respective of photosensitive drums. Each of the transfer rollers and the intermediate transfer belt define therebetween a contact range of which center lies downstream of the center of a contact range (transfer nip region) defined between the associated photosensitive drum and the endless belt in the direction of movement of the endless belt. The transfer roller deforms the path of movement of the intermediate transfer belt by contacting the intermediate transfer belt, and the resulting deformation causes the intermediate transfer belt to contact the periphery of the photosensitive drum over a predetermined range.

Abstract: A transfer device has a control circuit. The control circuit initiates supplying transfer power to one or more first transfer rollers and to a second transfer roller when a first transfer operation is initiated by a first transfer roller positioned most upstream with respect to a direction in which an intermediate transfer belt travels. The control circuit stops supplying the transfer power to the one or more first transfer rollers and to the second transfer roller when a second transfer operation is completed by the second transfer roller. The transfer power supplied to the one or more first transfer rollers and to the second transfer roller, respectively, is free from fluctuation during a period from the initiation of the first transfer operation performed first to the completion of the second transfer operation.

Abstract: A rotation speed of a heating roller 39a and a pressure roller 39b is variably controlled by a CPU 542 based on a sheet size to be printed, a direction the sheet is to be passed, and a number of sheets to be printed. Specifically, variable control of the rotation speeds of the heating roller 39a and the pressure roller 39b by the CPU 542 is based on an occurrence of a pass-through area 39b1 and a non-pass-though area 39b2 by a sheet of recording paper with respect to a roller lengthwise direction (axial direction) of a position at which the sheet of recording paper passes between the heating roller 39a and the pressure roller 39b, and controlled based on a thermal expansion coefficient of a roller diameter of the non-pass-though area 39b2 of the pressure roller 39b.

Abstract: A transfer device is provided including an intermediate transfer belt and transfer rollers associated with respective of photosensitive drums. Each of the transfer rollers and the intermediate transfer belt define therebetween a contact range of which center lies downstream of the center of a contact range (transfer nip region) defined between the associated photosensitive drum and the endless belt in the direction of movement of the endless belt. The transfer roller deforms the path of movement of the intermediate transfer belt by contacting the intermediate transfer belt, and the resulting deformation causes the intermediate transfer belt to contact the periphery of the photosensitive drum over a predetermined range.

Abstract: A cleaning unit includes a cabinet, a cleaning blade, a toner drop preventive sheet, and an auxiliary member. The cabinet has an opening facing an outer periphery of a photosensitive drum. The cleaning blade is operative to scrape down residual toner adhering to the outer periphery of the photosensitive drum. The toner drop preventive sheet is operative to prevent the residual toner scraped down by the cleaning blade from dropping between the photosensitive drum and the cabinet. The auxiliary member is disposed below the toner drop preventive sheet and is movable between a first position for receiving a bulk substance dropping from the toner drop preventive sheet and a second position for dropping the bulk substance received from the toner drop preventive sheet.

Abstract: In one embodiment of the original feeding device of the present invention, an original feeding device causes a drawing roller to contact an original, and draws the original for forwarding by rotating the drawing roller, and is provided with an original pressing member that generates frictional force on the original surface at a position on the side further upstream in a forwarding direction of the original than the drawing roller.

Abstract: A roller turning force generator is connected to a driving gear which is mounted on a shaft. The shaft is connected to offset roller assemblies disposed in an offset mechanism via connecting gears. The offset roller assemblies rotatably supported inside the offset mechanism are turned by a driving force transmitted from the roller turning force generator to discharge individual sheets of a printing medium in a sheet transport direction. The offset mechanism is linked to an offsetting force generator so that the offset mechanism can be shifted along a direction perpendicular to the sheet transport direction.

Abstract: Provided are photosensitive body or bodies 31b carrying toner; transfer roller(s) 31d, rotating and coming in contact with photosensitive body or bodies 31b, for causing toner image(s) formed on photosensitive body or bodies 31b to be electrostatically relocated onto paper 5; and paper transport means disposed upstream in transport direction(s) from transfer roller(s) 31d and comprising drive roller(s) 36d1 and idler roller(s) 36d2 holding lead edge portion(s) 5a of paper 5 in nip(s) formed therebetween and rotating so as to cause transport of same; drive roller(s) 36d1 and idler roller(s) 36d2 being disposed to the side, on which photosensitive body or bodies 31b is or are present, of a plane L more or less tangent to nip(s) formed between photosensitive body or bodies 31b and transfer roller(s) 31d; and direction(s) R of transport of paper from drive roller(s) 36d1 and idler roller(s) 36d2 being disposed so as to be directed toward transfer roller(s) 31d.

Abstract: A transfer device has a plurality of first transfer rollers provided, one in each of a plurality of first transfer regions. The first transfer rollers are arranged downstream of respective image carriers in a traveling direction of an intermediate transfer belt, so as to be out of contact with the image carriers through the belt. In the first transfer region that is located most upstream in the traveling direction, there is a pressure member provided upstream of the image carrier in the traveling direction for pressing the intermediate transfer belt against the image carrier.

Abstract: A discharge unit is disposed downstream of a principal transport path of a compound machine, and a shifter function is provided in this discharge unit. By shifting the paper passage position relative to a photosensitive drum when printing the front side and the paper passage position relative to the photosensitive drum when printing the back side, the region in which the surface electric potential of the photosensitive drum increases is diminished, and the region in which photographic fog is generated is made smaller. Thus, when printing the second and subsequent sheets, even when a slight amount of displacement of the transport position of the recording paper occurs, it is possible to suppress that recording paper making contact in the photographic fog region on the photosensitive drum, and defective printing can be prevented.

Abstract: A sheet transport guide includes a torsion coil spring (X). The spring (X) has a first arm (B4) with an end (B5). Through the end (B5), the spring (X) supports a rotation shaft of driven roller (R32) and applies elastic force to the roller (R32). Through the arm (B4) that is curved, the spring (X) guides a sheet toward a rotation roller R31. The spring (X) has a coil portion (B1) and an end (B3) of a second arm (B3) both fixed to a frame of an apparatus body. A plurality of driven rollers (R32) are aligned approximately parallel to a shaft (R31a) of the roller (R31). The rollers (R32) are each provided with the springs (X). A largest elastic force is applied to the roller (R32) at a predetermined reference position, and smaller elastic forces are applied to the other rollers (R32) at positions distant from the reference position.

Abstract: When a print request has been made, a control portion confirms whether or not there is a request for post-processing by a paper post-processing portion (step S2) and the type of recording paper that is to be used (step S8). If there is a request for post-processing, then it is determined whether or not a discharge tray is extended (step S3). If the result shows that the discharge tray is retracted, then a message urging the discharge tray to be extended is displayed on a liquid crystal display panel (step S6), and if the discharge tray is extended, then print processing is started (step S4). Furthermore, if the size of recording paper that is to be used is longer than the discharge tray in a retracted state, then a message urging the discharge tray to be extended is displayed on the liquid crystal display panel (step S6), and if the discharge tray is extended, then print processing is started (step S4).

Abstract: When handle region(s) of disengaging lever(s) is/are pulled in direction(s) tending to cause disengagement of engagement between access-controlling body or bodies and main body housing(s), respective action edge(s) of rotating region(s) may rotate about shaft(s) in direction(s) tending to cause disengagement of engagement. Upon rotating in direction(s) tending to cause disengagement of engagement, respective action edge(s) of rotating region(s) may press on and impel support plate(s) of main body housing(s). In accompaniment thereto, disengaging lever(s) may move upward, and respective downwardly directed engagement projection(s) of access-controlling body or bodies may be lifted up and extricated from respective upwardly directed engagement projection(s) of main body housing(s).

Abstract: A sheet stacking device includes: an evacuation section for transporting and ejecting sheets; a sheet exit tray for stacking the ejected sheets; an arm supporting member; and a sheet presser arm including a supported end at one end, a free end at the other end which is capable of pressing the sheets stacked on the sheet exit tray directly or via a contact member attached to the free end, and a flexure portion having flexibility between the supported end and the free end. The supported end is attached to the arm supporting member. The arm can apply, by the flexibility of the flexure portion, a pressing force to the sheets stacked on the sheet exit tray and a repulsive force to each of the ejected sheets when a front end of the ejected sheet strikes against the arm.

Abstract: A transfer device includes: a discharge type transfer element for transferring the developer to a sheet by discharging electric charge to a static latent image support through the sheet so as to form an image of an original thereon; and a transfer casing accommodating the transfer element, wherein the side on the sheet's entrance side is formed of an electrically insulating element, and is constructed such that the transfer element and transfer casing are arranged so as to be offset to the upstream side with respect to the rotational direction of the static latent image support, along the outer peripheral surface thereof and so that the upper end of the insulating element blocks up into the paper feed path, and the insulating element is adapted to be bent toward the sheet feed direction by virtue of an elastic member.

Abstract: An image forming apparatus is constituted so as to be equipped with transfer apparatus(es) having transfer roller(s) electrostatically transferring development image(s) from photosensitive drum(s) to transfer medium/media, and so as to be provided with transfer medium guide means disposed downstream in transfer medium transport path(s) from location(s) at which photosensitive drum(s) oppose transfer roller(s), and such that transfer medium guide location(s) of transfer medium guide means is/are variable.

Abstract: A cleaning unit includes a cabinet, a cleaning blade, a toner drop preventive sheet, and an auxiliary member. The cabinet has an opening facing an outer periphery of a photosensitive drum. The cleaning blade is operative to scrape down residual toner adhering to the outer periphery of the photosensitive drum. The toner drop preventive sheet is operative to prevent the residual toner scraped down by the cleaning blade from dropping between the photosensitive drum and the cabinet. The auxiliary member is disposed below the toner drop preventive sheet and is movable between a first position for receiving a bulk substance dropping from the toner drop preventive sheet and a second position for dropping the bulk substance received from the toner drop preventive sheet.

Abstract: A rotation speed of a heating roller 39a and a pressure roller 39b is variably controlled by a CPU 542 based on a sheet size to be printed, a direction the sheet is to be passed, and a number of sheets to be printed. Specifically, variable control of the rotation speeds of the heating roller 39a and the pressure roller 39b by the CPU 542 is based on an occurrence of a pass-through area 39b1 and a non-pass-though area 39b2 by a sheet of recording paper with respect to a roller lengthwise direction (axial direction) of a position at which the sheet of recording paper passes between the heating roller 39a and the pressure roller 39b, and controlled based on a thermal expansion coefficient of a roller diameter of the non-pass-though area 39b2 of the pressure roller 39b.