Media holddown suction force adjustment

An apparatus for adjusting a suction force for a media holddown, comprising:

• a transport unit to advance a media along a media advancement direction, wherein said transport unit comprises a media holddown surface with a plurality of suction zones arranged along said media advancement direction;
• and
• at least one vacuum source in fluid communication with at least one of said plurality of suction zones to adjust the suction force in said suction zones in accordance with said advancement of said media relative to said media holddown surface, wherein said at least one vacuum source is to:
• activate a first suction force in a first suction zone of said plurality of suction zones in response to said first suction zone being covered by said media or said first suction zone being about to be covered by said media due to advancement of said media along said media advancement direction, wherein said first suction zone is in fluid communication with a first chamber and activating said first suction force in said first suction zone comprises applying a vacuum to said first chamber;
• and
• after said activation of said first suction force in said first suction zone, activate a second suction force in a second suction zone of said plurality of suction zones in response to said second suction zone being covered by said media or said second suction zone being about to be covered by said media, wherein said second suction zone is in fluid communication with a second chamber separated by a wall from said first chamber and is located at a position along said media advancement direction beyond a position of said first suction zone, and activating said second suction force in said second suction zone comprises opening a first valve to establish fluid communication through said wall between said first chamber and said second chamber.

A computer-readable medium comprising computer-readable instructions, such that said instructions, when executed by a computer, cause said computer to:

• detect an advancement of a media relative to a media holddown surface along a media advancement direction, wherein said holddown surface has a plurality of suction zones arranged along said media advancement direction;
• and
• adjust a level of a suction force in said respective suction zones in accordance with said advancement of said media relative to said media holddown surface, in particular activating or deactivating said suction force in at least one of said suction zones in accordance with said advancement of said media relative to said media holddown surface, wherein adjusting said suction force comprises:
• activating a first suction force in a first suction zone of said plurality of suction zones in response to said first suction zone being covered by said media or said first suction zone being about to be covered by said media due to advancement of said media along said media advancement direction, wherein said first suction zone is in fluid communication with a first chamber and activating said first suction force in said first suction zone comprises applying a vacuum to said first chamber;
• and
• after said activating said first suction force in said first suction zone, activating a second suction force in a second suction zone of said plurality of suction zones in response to said second suction zone being covered by said media or said second suction zone being about to be covered by said media, wherein said second suction zone is in fluid communication with a second chamber separated by a wall from said first chamber and is located at a position along said media advancement direction beyond a position of said first suction zone, and activating said second suction force in said second suction zone comprises opening a first valve to establish fluid communication through said wall between said first chamber and said second chamber.