Print media vacuum holddown

A paper holddown device for printers having a vacuum force, comprising:

• a platen having a paper transport surface having a surface area sufficient for accommodating different sized paper thereon, a vacuum-force-side surface in communication with the vacuum force, and discrete vacuum ports coupling the surface area and vacuum-force-side surface;
• and
• a gate within each of the ports, wherein a sheet of paper on said surface covering individual ports causes a pressure differential change across an associated gate of each covered port, automatically moving the associated gate from a first position to a second position such that the vacuum force is exerted only through each covered port,
• wherein the platen includes a plate subjacent said paper transport surface, the plate having substantially same circumferential dimensions as the surface area, and the plate including a plurality of flaps wherein each one of said flaps is extending into a respective vacuum port adjacent thereto and forming said gate therein, each flap including a leakage means for pulling air from a vacuum port region above the flap with each of the respective ports when the flap is in the port-closed position.

A vacuum controlled holding apparatus for securing variably sized sheets of flexible material thereon, associated with a vacuum means for generating a vacuum force, comprising:

• plate means for sequentially receiving a flexible material sheet on a first surface thereof, the plate means having a plurality of vacuum ports leading to a second surface thereof, the second surface being subject to the force;
• gating means associated with each of the ports such that under a first condition, wherein a port is not covered by the sheet, the gating means is closed under influence of the force, and under a second condition, wherein a port is covered by the sheet, the gating means is automatically opened such that the force is exerted against the thereby holding the sheet to the first surface, the gating means including a plurality of flaps with a flap located at least partially within each port, each flap being biased to a first position opening the port and each flap including a leakage hole therethrough such that when the port is uncovered the force moves the flap to a second position closing the port and when the port is covered by a region of the sheet, the force creates a vacuum condition between the sheet and the flap via the leakage hole such that the flap moves under bias force to the first position, and each the flap being integrally molded into a wall of an associated vacuum port.