An image forming system has a transmission assembly, standard and auxiliary sheet feeders, standard and auxiliary trays, an image forming device and a controller. The transmission assembly is for switching transmission of a drive force of a motor selectively to the one of the standard and auxiliary sheet feeders. The controller determines whether sheet is absent in the standard tray. The controller, based on determining the sheet is absent in the standard tray and receipt of preceding data, control the transmission assembly to initiate to switch the transmission of the drive force to the auxiliary sheet feeder. Also the controller, based on receipt of control data received after preceding data, control the image forming device to form an image based on the control data.

Example implementations relate to initiation of a shortage model in a printing device. For example, initiation of a shortage model may include guidance of a page of print media through a printing device by a feedshaft and an upper paper guide, where the page of print media is held by a media control surface. A shortage model may be initiated based on an amount of data to be printed. An ink nozzle may be turned off based on the initiated shortage model.

A sheet-processing machine and a method for operating a sheet-processing machine are disclosed. Sheets from a stack are separated and are accelerated, by a primary acceleration device, to a first speed and are then accelerated by a secondary acceleration device, to a second speed and then are processed by a processing module at a processing speed. The first speed is at least 20% lower than the processing speed. A drive of the primary acceleration device and a drive of the secondary acceleration device and a drive of the processing module, each have dedicated drive control systems which are connected, by circuitry, to a machine controller of the sheet-processing machine.

Devices and processes include/use an inkjet printhead, a sheet transport positioned to move sheets of media past the inkjet printhead, a sheet registration device positioned to align the sheets of media, and a controller electrically connected to the inkjet printhead and the sheet registration device. The controller is adapted to periodically control the sheet registration device to align a first sacrificial sheet with a first edge of the sheet transport and align a second sacrificial sheet with a second edge of the sheet transport and that is opposite the first edge. The controller is adapted to control the inkjet printhead to eject ink from a first set of nozzles to the first sacrificial sheet and eject ink from a second set of nozzles to the second sacrificial sheet. The first set of nozzles contains different nozzles from the second set of nozzles.

In execution of aligning operation in a paper discharge device, every time the number of discharged print sheets reaches the number of aligning-start print sheets, a control unit performs aligning operation while the unit intermittently drives paper feed rollers of an image forming apparatus, to prevent discharge of a print-completed print sheet to a paper discharge table during aligning operation. Further, the control unit intermittently drives an elevation unit such that the print sheet on the top of a paper discharge table is always lower than a paper discharge position of a pair of paper discharge rollers. In execution of high-speed and high-volume printing, it is possible to perform alignment of the print sheet discharged on the paper discharge table without reducing productivity.

A medium transport apparatus includes a feeding section configured to nip a medium and feed the medium in a transport direction, a sensor disposed to face a side of the medium being transported in the transport direction, the sensor being configured to detect motion of the medium, and a control unit configured to stop the transport of the medium based on a detection value received from the sensor, in which during a period including a time at which a leading edge of the medium is nipped by the feeding section, the control unit continues transporting the medium irrespective of the detection value from the sensor.

A scanner having a medium transport device has: a medium placement section disposed so as to be exposed to the outside of a cabinet, the medium placement section having a placement surface on which paper to be transported is placed; a supply roller that feeds the paper in a transport direction by being rotated while in contact with a surface of the paper, the surface facing the placement surface; and a two-dimensional sensor disposed in the medium placement section. The two-dimensional sensor has a light emitting section that can emit light toward the paper placed in the medium placement section, and also has a light receiving section that can receive reflected light from the paper. The light receiving axis of the light receiving section intersects part of the cabinet.

An example printing device includes a memory to store data to print to a print media, a page pick mechanism to pick a page of the print media from a print media source, and a controller connected to the memory and the page pick mechanism. The controller is to control a timing of the page pick mechanism to pick a next page of print media based on a quantification of the data in the memory for a current page.

A printing apparatus includes a feeding unit, a pair of rollers, a printing unit, and a control unit. The control unit can execute skew correction. The control unit can execute control to convey a preceding printing medium and a succeeding printing medium by the pair of rollers in a state in which a trailing edge portion of the preceding printing medium and a leading edge portion of the succeeding printing medium overlap. The control unit sets an execution timing of the skew correction for the succeeding printing medium based on positions of the preceding printing medium and the succeeding printing medium if a predetermined condition is met. The predetermined condition is that the preceding printing medium reaches a position at which a remaining print range for the preceding printing medium equals a predetermined print range.

A printing apparatus includes a feeding roller configured to feed a printing sheet stacked on a stacking unit, a conveyance roller configured to convey the printing sheet fed by the feeding roller, a printing unit configured to print the printing sheet conveyed by the conveyance roller, a conveyance control unit configured to control conveyance of printing sheets so that the trailing edge of a preceding sheet as a printing sheet precedingly fed from the stacking unit and the leading edge of a succeeding sheet as a printing sheet succeedingly fed from the stacking unit overlap each other, and a determination unit configured to determine whether to convey the succeeding sheet to a position facing the printing unit while keeping an overlap state between the preceding sheet and the succeeding sheet.