In one example, a media support with a continuous belt rotatable and suction cups lengthwise along the belt and in lines laterally across the belt to hold down a sheet of print media as the sheet is moved through a hold down area, a vacuum pump to supply vacuum to the suction cups. The vacuum control system is configured to close a supply of vacuum to all of the suction cups in the hold down area and then open the supply of vacuum sequentially to each of multiple lines of suction cups as each line enters the hold down area and then close the supply of vacuum sequentially to each of the multiple lines of suction cups as each line leaves the hold down area until all of the suction cups in the hold down area are closed.

In one example, a media support includes a continuous loop belt and multiple suction cups arranged along the outer perimeter of the belt. Each suction cup has a port aligned with a hole in the belt so that air may be evacuated from the suction cup when connected to a vacuum source.

Perforated endless conveying belts are stretched between drive and idle rollers. A suction box is arranged between upper and lower belt portions of the perforated endless conveying belts. Abutment members are attached to positions of a support corresponding to the perforated endless conveying belts and pressed against the perforated endless conveying belts. The upstream of the suction box from the abutment members forms an attracting area, and intake holes are formed therein. Lifting plates extend to at least an intake hole range of the attracting area between the perforated endless conveying belts. The lifting plates move between a first position to vertically open the intake holes and project from conveying surfaces of the perforated endless conveying belts and a second position to close the intake holes and retract from the conveying surfaces of the perforated endless conveying belts.

A marker transport system and a method of operating the marker transport system. A group of print bars is located with respect to a marker transport platen and a marker transport belt. A vacuum source and a pneumatic solenoid block are associated with the marker transport platen. The marker transport platen includes airflow sections divided into process-direction slots and cross-section direction slots. The cross-section direction slots are located beneath the print bars and are connected to the vacuum source via the pneumatic solenoid block, which facilitates an individual control of each of the cross-process direction slots. Pneumatic valves are associated with the pneumatic solenoid block, which supplies a flow of vacuum to the cross-process direction vacuum slots. The pneumatic vales can be timed to allow the vacuum to be present when a sheet is present over a corresponding vacuum slot among the process-direction slots and the cross-section direction slots.

A printing system includes a driving belt configured to drive media through the printing system relative to one or more print heads and a vacuum conveyor system. The vacuum conveyor system includes a vacuum chamber cover having a first surface and a second surface opposite the first surface, as well as a plurality of openings through the cover from the first surface to the second surface. A number of seals are disposed to match the location of openings. Each seal extends along the length of the vacuum chamber cover and is drivable to open or close a region with openings. A vacuum chamber below the second surface of the vacuum chamber cover is configured to apply a vacuum to the media through one or more of the openings that are open. The applied vacuum constrains the media on the driving belt by flattening it against the driving belt.

A transport device transports an individualized sheet-shaped workpiece. The transport device includes: an annular transport belt having a first surface and a second surface opposite to the first surface and having a plurality of suction holes extending between the first surface and the second surface; first and second decompression chambers arranged along a moving direction of the transport belt; and a vacuum degree adjusting mechanism provided in the first decompression chamber and adjusting a vacuum degree in the first decompression chamber. The first and second decompression chambers each abut against the second surface, and each suction the workpiece through at least one of the plurality of suction holes toward the first surface such that the transport belt is capable of transporting the workpiece in the moving direction in a suspended state from the first surface.

Examples described herein include devices and methods for adjusting a suction force for a media holddown, comprising detecting an advancement of a media (114) relative to a media holddown surface along a media advancement direction (X), wherein the holddown surface has a plurality of suction zones arranged along the media advancement direction, and adjusting a suction force in the respective suction zones in accordance with the advancement of the media relative to the media holddown surface.

A media transport system includes a vacuum plenum and a belt positioned over the vacuum plenum. The belt includes at least one member having a first region and a second region that both include holes that enable the vacuum plenum to apply a force to hold print media against the belt. The belt also includes slots formed through the at least one member in an inter-copy gap positioned between the first region and the second region. Each slot is formed with a larger area than an area of each hole.

The invention relates to a vacuum system for securing items in printing machines, comprising a printing table (2) with a perforated surface and, in relation thereto, a vacuum system for securing the items to be printed, which comprises a box structure (8) connected to a suction system and provided with a perforated wall in relation to the surface of the printing table (2), said box structure (8) having lateral panels that vertically close the interior thereof, which panels can be moved in order to adjust the gap between them in relation to the width of the items to be printed.

A media transport system includes a vacuum plenum and a belt positioned over the vacuum plenum. The belt includes at least one member having a first region and a second region that both include holes that enable the vacuum plenum to apply a force to hold print media against the belt. The belt also includes slots formed through the at least one member in an inter-copy gap positioned between the first region and the second region. Each slot is formed with a larger area than an area of each hole.