摘要:
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.
摘要:
A duplex printing device comprises a duplex printing master on which a first image and a second image are perforated in series over the length of a single plate, and a simplex printing master on which a third image having an image area equivalent to the first image and the second image is perforated over the length of a single plate. The duplex printing master or simplex printing master is wrapped around an outer peripheral surface of a print drum, thereby enabling a duplex printing operation in which one of the first image and second image is printed by pressing a front side of a sheet against the duplex printing master on the print drum using pressing means which can be brought into and out of contact with the print drum, after which the other of the first image and the second 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 pressing means, and a simplex printing operation in which the third image is printed by pressing one side of the sheet against the simplex printing master on the print drum. When power is supplied to the duplex printing device, during mode clearance for clearing various modes executed by the duplex printing device, and so on, a preset initial set mode can be switched between a duplex print mode for performing the duplex printing operation and a simplex print mode for performing the simplex printing operation.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The invention provides an option-type paper feeding device that can contribute to enhancing printing operation efficiency while taking advantage of variable printing speed in a printing apparatus. A high-volume paper feeding device includes: a paper stacking section; a paper feeding mechanism; and an intermediate transport section connected to a paper feeding section of a printing apparatus such as a stencil printing apparatus. The intermediate transport section includes: a first paper transport means; and a second paper transport means provided downstream of the first paper transport means, and an inkjet printing section is provided above the first paper transport means. The transport speed of the first paper transport means is fixed to a speed suitable for printing by the inkjet printing section, while the transport speed of the second paper transport means is variable. The transport speed of the second paper transport means is adjusted by control means (not shown in drawings) in accordance with the printing speed of a printing apparatus connected to the high-volume paper feeding device.
摘要:
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.
摘要:
A stencil printer of the present invention 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 for storing a sheet, carrying an image on one surface thereof, and then refeeding it toward a gap between the print drum and the press roller, a path selector selectively movable to a first position for guiding the sheet toward the refeeding device or a second position for guiding it toward the intermediate conveyor, and a switching device for causing the press roller to selectively remain in contact with the print drum over a first range corresponding to the first image, a second range corresponding to the second image or a third range covering both of the first and second images.
摘要:
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.