Printer band edge hold down systems

Patent metadata

Field	Value
Publication number	US-10265978-B2
Application number	US-201715491831-A
Country	US
Kind code	B2
Filing date	Apr 19, 2017
Priority date	May 25, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

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.

First claim

The invention claimed is:

1. 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 pneumatic cylinder connected to a first rack, and
a first pivot gear configured to engage the first rack;

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 first pivot gear of 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 during printing by applying pressure to a surface of the substrate.

2. The system of claim 1 , wherein the exit tension assembly comprises:
a constant-force spring connected to a second rack; and
a second pivot gear that engages the second rack,
wherein the second end of the tensioned band is connected to the second pivot gear.

3. A tension assembly comprising:
a pneumatic cylinder connected to a rack;
a pivot gear that engages the rack; and
a tensioned band having a first end that is connected to the pivot gear 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 a printer during printing by applying pressure to a surface of the substrate.

4. The tension assembly of claim 3 , wherein the other tension assembly comprises:
a constant-force spring connected to a second rack;
a second pivot gear that engages the second rack,
wherein the second end of the tensioned band is connected to the second pivot gear.

5. The tension assembly of claim 3 , wherein a tension level of the tensioned band is held substantially constant by the pneumatic cylinder during printing.

6. The tension assembly of claim 3 , wherein the pneumatic cylinder is connected to the rack via a floating joint that allows misalignment between the pneumatic cylinder and the rack.

7. The tension assembly of claim 3 , wherein linear motion of the rack effected by the pneumatic cylinder causes rotational motion of the pivot gear, thereby increasing or decreasing a tension level of the tensioned band.

8. The tension assembly of claim 3 , wherein the rack is mounted to a slide plate that is disposed within a track that guides linear motion of the rack.

9. The tension assembly of claim 3 , further comprising:
a guard that protects teeth of the pivot gear from contaminants,
wherein the guard is pivotably connected to the pivot gear.

10. The tension assembly of claim 9 , further comprising:
a pin disposed along a side wall of the pivot gear,
wherein the pin causes the guard to rotate upward as the pivot gear rotates past a specified position.

11. The tension assembly of claim 3 , further comprising:
a proximity sensor configured to detect a tension level of the tensioned band and indicate whether the tension level meets a specified threshold.

12. The tension assembly of claim 11 , wherein the tensioned band is at least partially comprised of metal, and wherein the proximity sensor is an inductive proximity sensor.

13. The tension assembly of claim 3 , wherein the pneumatic cylinder, the rack, and the pivot gear at least partially reside within a housing that is mounted to a rigid feature of the printer.

14. The tension assembly of claim 3 , wherein vertical motion of the tensioned band is automated using a sensor disposed upstream of the tension assembly in the media feed direction that detects a thickness of the substrate and one or more motors that effect vertical movement of the tensioned band to a height substantially matching the thickness of the substrate.

15. A method comprising:
enabling a user to place a substrate onto a transfer belt of a printer;
receiving, by an edge hold down system, input specifying a thickness of the substrate,
wherein the edge hold down system includes
an entry tension assembly,
an exit tension assembly 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;

adjusting a vertical height of the tensioned band to substantially match the thickness of the substrate; and
actuating a pneumatic cylinder of the entry tension assembly to apply tension to the tensioned band,
wherein the tensioned band holds the substrate substantially flat against the transfer belt of the printer during printing by applying pressure to a surface of the substrate.

16. The method of claim 15 , wherein the tensioned band contacts the surface of the substrate substantially proximate to an outer edge of the substrate that is parallel to the media feed direction.

17. The method of claim 15 , wherein the input is provided by a sensor disposed upstream of the entry tension assembly in the media feed direction.

18. The method of claim 17 , wherein the sensor is configured to automatically determine the thickness of the substrate upon determining the substrate is a specified distance away from the entry tension assembly or a print head.

19. The method of claim 15 , wherein the input is provided by a user via an interface displayed by the printer or an electronic device communicatively coupled to the printer.

20. The method of claim 15 , wherein said adjusting the vertical height of the tensioned band is performed automatically by a first motor that is coupled to the entry tension assembly and a second motor that is coupled to the exit tension assembly, and wherein the first motor and the second motor enable bi-directional adjustment of the vertical position of the entry tension assembly and the exit tension assembly.

21. The method of claim 15 , wherein the edge hold down system is one of multiple edge hold down systems disposed above the substrate.

Assignees

• Electronics For Imaging Inc

Inventors

• Vaillancourt Keith
• PORTER Christopher Andrew

Classifications

• B41J11/0085

  Using suction for maintaining printing material flat (on rotatable drums B41J13/226) · CPC title

• B41J11/0045

  Guides for printing material (curl smoothing B41J11/0005; platens B41J11/02, B41J11/06; guiding webs B41J15/046) · CPC title

• B41J13/0072

  Handling wide cut sheets, e.g. using means for enabling or facilitating the conveyance of wide sheets · CPC title

• B41J15/16 Primary

  Means for tensioning or winding the web · CPC title

• B41J3/28 Primary

  for printing downwardly on flat surfaces, e.g. of books, drawings, boxes {, envelopes, e.g. flat-bed ink-jet printers} · CPC title