Printhead position control

Patent metadata

Field	Value
Publication number	US-10071549-B2
Application number	US-201615059472-A
Country	US
Kind code	B2
Filing date	Mar 3, 2016
Priority date	Feb 26, 2015
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

Systems and methods for printhead position control. The system comprises a controller that identifies a target distance for moving a printhead in a lateral direction to compensate for lateral shifts in a web of print media as the web travels in a continuous-forms printer in a conveyance direction. The controller also identifies a maximum distance for moving the printhead in the lateral direction based on an allowable print error in a color plane of the printer and one or more previous positions of the printhead. The control further moves the printhead for a distance that is a lesser of the maximum distance and the target distance.

First claim

I claim:

1. An apparatus comprising:
a controller configured to determine a distance for moving a printhead in a lateral direction to compensate for a lateral shift in a web of print media as the web travels in a continuous-forms printer in a conveyance direction;
the controller configured to determine a threshold distance for moving the printhead based on an allowable print error between nozzles of the printhead, to determine whether the distance exceeds the threshold distance, and to direct the printhead to move the threshold distance to compensate for the lateral shift if the distance exceeds the threshold distance.

2. The apparatus of claim 1 wherein:
the controller is configured to determine the threshold distance based at least in part on a length between the printhead and an upstream printhead.

3. The apparatus of claim 1 wherein:
the controller is configured to direct the printhead to move the distance to compensate for the lateral shift if the distance does not exceed the threshold distance.

4. The apparatus of claim 1 further comprising:
a continuous-forms printer.

5. A method comprising:
determining a distance for moving a printhead in a lateral direction to compensate for a lateral shift in a web of print media as the web travels in a continuous-forms printer in a conveyance direction;
determining a threshold distance for moving the printhead based on an allowable print error between nozzles of the printhead;
determining whether the distance exceeds the threshold distance; and
directing the printhead to move the threshold distance to compensate for the lateral shift if the distance exceeds the threshold distance.

6. The method of claim 5 further comprising:
determining the threshold distance based at least in part on a length between the printhead and an upstream printhead.

7. The method of claim 5 further comprising:
directing the printhead to move the distance to compensate for the lateral shift if the distance does not exceed the threshold distance.

8. A non-transitory computer readable medium embodying programmed instructions which, when executed by a processor, are operable for performing a method comprising:
determining a distance for moving a printhead in a lateral direction to compensate for a lateral shift in a web of print media as the web travels in a continuous-forms printer in a conveyance direction;
determining a threshold distance for moving the printhead based on an allowable print error between nozzles of the printhead;
determining whether the distance exceeds the threshold distance; and
directing the printhead to move the threshold distance to compensate for the lateral shift if the distance exceeds the threshold distance.

9. The medium of claim 8 wherein the method further comprises:
determining the threshold distance based at least in part on length between the printhead and an upstream printhead.

10. The medium of claim 8 wherein the method further comprises:
directing the printhead to move the distance to compensate for the lateral shift if the distance does not exceed the threshold distance.

Assignees

• Johnson Scott Richard
• Ricoh Co Ltd

Inventors

• Johnson Scott Richard

Classifications

• B41J2/04505 Primary

  aiming at correcting alignment · CPC title

• B41J2/2146

  for line print heads · CPC title

• B41J2/04586

  controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type · CPC title

• B41J25/001 Primary

  Mechanisms for bodily moving print heads or carriages parallel to the paper surface · CPC title