Tohoku Ricoh Co., Ltd.

Mituru Takahashi

Tomotaka Osada

Yoshiyuki Araseki

Keiichi Satoh

Hideaki Matsuda

Hironobu Takasawa

Hideyuki Kagawa

Toshiharu Hasegawa

Atsushi Ashikagaya

Naoki Okazaki

Yoshihito Ebina

Nobuyuki Hoshi

Masaru Ohdaira

Tomohiro Monden

An inkjet printing apparatus that can perform printing with a single printing speed even in a case of being connected with a post-processing apparatus having a different transport speed, and that can suppress increased apparatus costs. A discharge transport portion positioned at a connection side of a post-processing apparatus of the inkjet printing apparatus is constituted by transport roller pairs and discharge roller pairs, and is capable of being driven independently from the inkjet transport portion. When the transport speed of the post-processing apparatus is different from the printing speed, printed papers are temporarily stopped at the discharge transport portion. After this, transport recommences with a predetermined timing matched to the transport speed of the post-processing apparatus, and papers are fed to the post-processing apparatus. In a case of continuous printing, a distance between the papers (paper feeding interval) is adjusted in the inkjet printing apparatus to enable transport jams to be avoided.

Inkjet printing apparatus

A stencil printing apparatus for wrapping a master around an outer circumferential surface of a plate cylinder to perform printing, the stencil printing apparatus being capable of preventing the occurrence of abnormal images or afterimage phenomenon which causes confidential information leakage, without increasing cost or causing any problems. This stencil printing apparatus has time measuring means for measuring a leaving time during which the apparatus is left stand, and when a plate discharge command is output before the leaving time exceeds a first predetermined time while the master is wrapped around the outer circumferential surface, the stencil printing apparatus is shifted to a standby state after the master is discharged from the outer circumferential surface.

Stencil printing apparatus

A printer of the present invention allows a plurality of sheet feeding apparatuses, each having a particular sheet feed speed range adaptive to a plurality of print speeds, to be selectively connected thereto. When any one of the sheet feeding apparatuses is connected to the printer, a controller automatically sets a print speed range on the printer in accordance with print speed range information corresponding to the sheet feeding apparatus.

Printer having plural sheet feeding apparatuses with variable print speeds

A printing method and a printing apparatus including a stencil printing apparatus and so on. Focusing on the relationship that exists between copy number and master position displacement that occurs during printing, by determining by pretest and setting top-bottom shift correction values in accordance with parameters including copy number that affect printed master position displacement in the direction of rotation of a plate cylinder, and during printing, utilizing conventionally used top-bottom shift means to automatically execute top-bottom shift correction in accordance with the set top-bottom shift correction values, printing position displacement can be prevented from occurring, waste of master and printing medium such as paper can be eliminated and, in addition, the operation time can be shortened and the number of operation steps can be reduced. The CPU of control means, each time the copy number counted by a paper discharge sensor reaches a predetermined copy number, reads a top-bottom shift correction value corresponding to a predetermined copy number from a ROM, and during printing, controls a top-bottom shift motor of top-bottom shift means to execute a top-bottom shift correction in accordance with the read top-bottom shift correction value.

Printing method and printing apparatus

A duplex printing apparatus capable of printing by performing a slow-up operation on the printing speed so that it increases from a low speed to a set speed at the time of duplex printing. Control means controls, on the basis of a drum rotation position signal and a drum speed signal from a home position sensor and an unshown encoder sensor, a sheet feeding unit, printing unit, sheet discharge unit, sheet re-feeding means and switching member, such that the printing speed (drum speed) slows up from a low speed to a set speed in each rotation of a plate cylinder, which corresponds to feeding of each sheet to the printing unit when duplex printing is started, and further controls a stepping motor of the sheet re-feeding means such that conveyance speed of a sheet receiving board synchronizes with the printing speed.

Duplex printing apparatus having control unit to control printing speed

A sheet feeding apparatus includes a sheet stacking section configured to stack a number of sheets, a sheet feeding mechanism configured to feed the sheet stacked on the sheet stacking section one by one, and an intermediate conveying device configured to convey the sheet fed from the sheet feeding mechanism to an image forming apparatus. The intermediate conveying device includes a plurality of sheet conveying devices arranged in an intermediate sheet conveying path at certain intervals to convey the sheet fed from the sheet feeding mechanism, at least one driving device configured to drive each of the plurality of sheet conveying devices, and a plurality of sheet detecting devices arranged in the intermediate sheet conveying path at certain intervals to detect a sheet length by detecting at least one of a leading edge and a trailing edge of the conveyed sheet. The sheet feeding apparatus further includes a control device configured to judge the length of a first sheet according to signals sent from the plurality of sheet detecting devices at an initialization time at which the conveying operation for the first sheet is completed, in which when the sheet feeding apparatus and the image forming apparatus are mechanically connected and are allowed to communicate with each other, the control device stops a sheet conveying operation of the image forming apparatus if the length of a sheet is judged to be different from the length of the first sheet after the initialization time.

Large capacity sheet feeding apparatus having an intermediate conveying device

A stencil printing apparatus which suppresses master consumption by switching between simplex printing using a simplex master and single-step duplex printing using a duplex master automatically in accordance with master information and sheet information comprises a printing drum and pressing means, and can be made to switch between duplex printing, in which a rear surface printing step is performed after a front surface printing step, and simplex printing by wrapping a duplex master formed with a first engraved image and a second engraved image around the printing drum during duplex printing, and wrapping a simplex master formed with a third engraved image for simplex printing around the printing drum during simplex printing. Master identification information, indicating whether the master was engraved with duplex printing images or a simplex printing image during engraving, is stored in a storage unit in association with plate cylinder identification information, and either a duplex printing mode or a simplex printing mode is selected on the basis of plate cylinder identification information obtained anew when an operation command or a plate cylinder attachment/detachment command is input into the apparatus, and the master identification information stored in the storage unit.

Stencil printing apparatus for duplex or simplex printing

A paper conveyance apparatus includes a stacking portion; a feeding mechanism to extract and feed paper from the stacking portion one sheet at a time; and an intermediate portion for conveying the fed paper to the vicinity of a feeding port or feeding device of a main body of an image forming apparatus. The intermediate portion includes a plurality of conveyance devices and a plurality of paper detecting devices disposed from the upstream side to the downstream side of a conveyance path. The paper conveyance apparatus further includes a control device for reducing the conveyance speed of the plurality of conveyance devices when the leading edge of the paper is detected by a detecting device disposed at least one device further toward the upstream side than a paper detecting device disposed furthest downstream of the plurality of detecting devices.

Paper conveyance apparatus

A stencil printer includes at least an upstream and a downstream printing section, as seen in the direction of sheet conveyance, each including a print drum and a press roller for pressing a sheet against the print drum. An intermediate conveyor, positioned between the upstream and downstream printing sections, conveys the sheet from the former toward the latter. A dual master, formed with a first and a second image, is wrapped round the print drum of the upstream printing section. This printing section includes a refeeding device, a path selector, and a switching device.

Multi-drum stencil printer with duplex printing sections

Provided is a bulk paper feeding device with an intermediate conveyor comprising a carrier capable of carrying a large quantity of paper, a paper feeding mechanism for picking up and feeding one sheet at a time of the paper from the carrier, and an intermediate conveyor for transporting a sheet of paper fed from the feeding mechanism to the main paper feeding table of the paper feeder on the body of the image forming device or to the vicinity of a paper feeding port that faces the main paper feeding means of the paper feeder.

Bulk paper feeding device with intermediate conveyor for image forming device

A duplex printing device including a duplex printing master on which two images are perforated in series over a single plate, and a simplex printing master on which a third image is perforated over the single plate. Either master is wrapped around an outer peripheral surface of a print drum, enabling duplex printing operation in which one of the two images is printed by pressing a front side of a sheet against the duplex printing master on the print drum using a presser which can be brought into and out of contact with the print drum, after which the other image is printed by reversing and refeeding the sheet and pressing a reverse side of the sheet against the duplex printing master on the print drum using the presser, and a simplex printing operation done by pressing one side of the sheet against the simplex printing master.

Duplex printing device configured for duplex printing on the front and reverse sides of a sheet of printing paper and simplex printing on only one side of the sheet

A printer including a plurality of print drums and capable of producing, e.g., color printings is disclosed. When a closed position sensor responsive to a door outputs a close signal and when a drum sensor assigned to a print drum to be mounted outputs an absence signal, a controller controls drum drive sections such that a mount/dismount drive section assigned to the print drum to be mounted takes the position corresponding to a mount position. Also, in response to a mount position signal output from a mount position sensor, the controller controls the drum driving device such that the mount/dismount drive section stops at the position corresponding to the mount position. The printer allows an operator thereof to mount the print drums without pressing, e.g., mount/dismount keys each time and thereby saves time.

Printer with a plurality of print drums

A stencil printer capable of printing a multicolor image on a sheet of the present invention includes a plurality of drums arranged side by side in an intended direction of sheet transport at a preselected interval. Ink of particular color is fed to the inner periphery of each drum carrying a respective master around its outer periphery. An intermediate transport device transports a sheet from an upstream drum to a downstream drum. A controller controls the sheet conveyance speed of the intermediate transport device and/or the print conveyance speed of the downstream drum in accordance with the size and/or the position of the sheet. The printer allows a minimum of double printing and misregister to occur by making up for a delay of transport of the sheet to the downstream drum.

Stencil printer

A stencil printer includes a plurality of ink drums spaced from each other in the direction of paper conveyance and each having a respective master wrapped therearound. An upstream ink drum and pressing means movable into and out of contact with the upstream ink drum define an upstream print position. A downstream ink drum and pressing means movable into and out of contact with the downstream ink drum define a downstream print position. An intermediate conveyor is located between the upstream print position and the downstream print position for conveying a paper carrying an image printed at the upstream print position toward the downstream print position. A distance which the paper moves from the upstream print position to the downstream print position is longer than a distance between the upstream print position and the downstream print position. Defective printing is reduced even when the peripheral speed of the upstream ink drum and that of the downstream ink drum are different from each other.

A stencil printer of the present invention includes at least one ink drum for wrapping a master around its outer periphery. An ink feed device feeds ink to the master wrapped around the ink drum. A pressing member is movable into and out of contact with the ink drum at a position where it faces the ink feed device. An image is printed on a paper fed from a paper feed section at a print section where the ink drum and pressing member face each other. A belt conveyor includes a belt extending between the paper feed section located upstream of the print section in the direction of paper conveyance and a paper discharge section located downstream of the print section in the same direction through the print section. The belt conveys the paper fed from the paper feed section while causing it to electrostatically adhere thereto. The paper is sufficiently electrostatically adhered to the belt before it reaches the print section, so that air suction, an air knife, a separator or the like is not necessary. The paper is smoothly conveyed to the print section without any noise and surely separated from the ink drum. Because the pressing member brings the belt into and out of contact with the ink drum, an exclusive mechanism for so moving the belt is not necessary.

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Miyagi, Japan

Mituru Takahashi