Printer band edge hold down systems
Edge hold down (EHD) systems are described herein that enable high print quality to be achieved more consistently, particularly when using substrates that are rigid or include one or more defects. Each EHD system includes a tensioned band for holding down an edge of a substrate as it passes through a printer assembly without impacting the print area. The tensioned band can be affixed between an entry tension assembly and an exit tension assembly disposed downstream of the entry tension assembly in the media feed direction. The tensioned band holds the substrate substantially flat against a transfer belt during printing by applying pressure to the surface of the substrate. The tensioned band generally contacts the surface of the substrate substantially proximate to an outer edge that is parallel to the media feed direction.
1. A tension assembly comprising:
a mounting block;
a vertical adjustment screw having a first segment that is anchored within a rigid feature of a printer and a second segment that is installed within the mounting block;
a vertical lock disposed along an outer surface of the mounting block,
wherein the vertical lock engages the second segment of the vertical adjustment screw, and
wherein vertical movement of the tension assembly is enabled through rotation of the vertical lock;
a tensioner mounted to the mounting block; and
a tensioned band having a first end that is connected to the tensioner and a second end that is connected to another tension assembly disposed downstream of the tension assembly in a media feed direction,
wherein the tensioned band holds a substrate substantially flat against a transfer belt of the printer during printing by applying pressure to a surface of the substrate.
2. The tension assembly of claim 1 , wherein rotation of the vertical lock causes rotation of the vertical adjustment screw and vertical movement of the mounting block and the tensioner to which the tensioned band is connected.
3. The tension assembly of claim 1 , wherein the rigid feature of the printer is a bar or a support beam that extends across a bed of the printer.
4. The tension assembly of claim 1 , wherein the tensioned band contacts the surface of the substrate substantially proximate to an outer edge parallel to the media feed direction.
5. The tension assembly of claim 1 , wherein the transfer belt is a vacuum belt.
6. The tension assembly of claim 1 , further comprising:
a band tensioning nut that, when rotated, causes tension of the tensioned band to be altered.
7. A system comprising:
an entry tension assembly that is connected to a first structural feature of a printer,
wherein the entry tension assembly includes:
a mounting block,
a vertical adjustment screw having a first segment that is anchored within the first structural feature of the printer and a second segment that threadably engages the mounting block, and
a lock accessible along an outer surface of the mounting block,
wherein the lock engages the second segment of the vertical adjustment screw in such a manner that vertical movement of the entry tension assembly is enabled through rotation of the lock;
an exit tension assembly that is connected to a second structural feature of the printer,
wherein the exit tension assembly is disposed downstream of the entry tension assembly in a media feed direction; and
a tensioned band having a first end that is connected to the entry tension assembly and a second end that is connected to the exit tension assembly,
wherein the tensioned band holds a substrate substantially flat against a transfer belt of the printer by applying pressure to a surface of the substrate.
8. The system of claim 7 , wherein the exit tension assembly includes:
a mounting block,
a vertical adjustment screw having a first segment that is anchored within the second structural feature of the printer and a second segment that threadably engages the mounting block, and
a lock accessible along an outer surface of the mounting block,
wherein the lock engages the second segment of the vertical adjustment screw in such a manner that vertical movement of the exit tension assembly is enabled through rotation of the lock.
9. The system of claim 8 , wherein vertical position of the entry tension assembly is adjustable independent of vertical position of the exit tension assembly.
10. The system of claim 7 , wherein the entry tension assembly further includes:
a tensioner to which the first end of the tensioned band is connected.
11. The system of claim 10 , wherein the entry tension assembly further includes:
a band tensioning nut that, when rotated, causes tension of the tensioned band to be altered.
12. The system of claim 10 , wherein vertical position of the tensioned band is adjustable from 1 millimeter (mm) to 50 mm above the transfer belt.
13. The system of claim 10 , wherein the entry and exit tension assemblies are arranged such that the tensioned band contacts the surface of the substrate proximate to an outer edge that is parallel to the media feed direction.