Test patterns for optimizing nozzle alignment of an ink-jet marking engine

Patent metadata

Field	Value
Publication number	US-9956799-B1
Application number	US-201715413769-A
Country	US
Kind code	B1
Filing date	Jan 24, 2017
Priority date	Jan 24, 2017
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

Systems and methods are provided for test patterns that detect misalignment. One embodiment is a printer that includes a marking engine having rows of nozzles. The rows are separated along a Y direction, and each row of nozzles extends in an X direction. The printer also includes a controller that directs the marking engine to print multiple bands of a test pattern. Each band is printed by selecting nozzles in a first row, selecting nozzles in a second row that occupy adjacent X positions to the selected nozzles of the first row, and forming a band having multiple marks. Each mark includes a continuous line from a nozzle in the first row and a continuous line from a nozzle in the second row. Each band of the test pattern is printed by ejecting ink from nozzles in a different combination of nozzles.

First claim

We claim:

1. A system comprising:
a printer comprising:
a marking engine comprising rows of nozzles that eject ink onto a print medium, wherein the rows are separated from each other along a Y direction, and each row of nozzles extends in an X direction that is in-plane with the Y direction; and
a controller that directs the marking engine to print multiple bands of a test pattern, wherein each band is printed by selecting nozzles in a first row at regularly spaced intervals, selecting nozzles in a second row that occupy adjacent X positions to the selected nozzles of the first row, and ejecting continuous lines of ink from the selected nozzles in the first row and the selected nozzles in the second row onto a print medium to form a band comprising multiple evenly spaced marks separated by empty space, each mark comprising a first continuous line from a nozzle in the first row and a second continuous line from a nozzle in the second row, at least a portion of the second continuous line shares Y coordinates with at least a portion of the first continuous line, and
each band of the test pattern is printed by ejecting ink from a different combination of nozzles.

2. The system of claim 1 wherein:
the controller determines that a row is misaligned with respect to the print medium in response to determining that marks in bands of the test pattern have a thickness that is different than a target value.

3. The system of claim 1 wherein:
the controller determines that a row is misaligned with respect to the print medium in response to determining that marks in different bands of the test pattern have different amounts of thickness.

4. The system of claim 1 wherein:
for each mark, the continuous line from the nozzle in the first row comprises a first half of the mark in the X direction, and
the continuous line from the nozzle in the second row comprises a second half of the mark in the X direction.

5. The system of claim 4 wherein:
the first half of a mark extends into a second band; and
the second half of the mark extends into a third band.

6. The system of claim 4 wherein:
the first half and the second half of each mark are contiguous.

7. The system of claim 1 wherein:
neighboring bands of the test pattern are printed by combinations of rows that have at least one nozzle in common.

8. The system of claim 1 wherein:
the test pattern repeats in the Y direction at a first frequency; and
each band of the test pattern includes a combination of mark and empty space that repeats in the X direction at a second frequency that is higher than the first frequency.

9. The system of claim 1 wherein:
the marking engine comprises printheads that remain stationary as the test pattern is printed.

10. The system of claim 1 wherein:
the first row and the second row are separated in the Y direction by at least one other row.

11. A method comprising:
selecting a marking engine comprising rows of nozzles that eject ink onto a print medium, wherein the rows are separated from each other along a Y direction, and each row of nozzles extends in an X direction that is in-plane with the Y direction; and
directing the marking engine to print multiple bands of a test pattern, wherein each band is printed by:
selecting nozzles in a first row at regularly spaced intervals;
selecting nozzles in a second row that occupy adjacent X positions to the selected nozzles of the first row; and
ejecting continuous lines of ink from the selected nozzles in the first row and the selected nozzles in the second row onto a print medium to form a band comprising multiple evenly spaced marks separated by empty space, each mark comprising a first continuous line from a nozzle in the first row and a second continuous line from a nozzle in the second row, at least a portion of the second continuous line shares Y coordinates with at least a portion of the first continuous line, and

each band of the test pattern is printed by ejecting ink from nozzles in a different combination of nozzles.

12. The method of claim 11 further comprising:
determining that a row is misaligned with respect to the print medium in response to determining that marks in bands of the test pattern have a thickness that is different than a target value.

13. The method of claim 11 further comprising:
determining that a row is misaligned with respect to the print medium in response to determining that marks in different bands of the test pattern have different amounts of thickness.

14. The method of claim 11 wherein:
for each mark, the continuous line from the nozzle in the first row comprises a first half of the mark in the X direction, and
the continuous line from the nozzle in the second row comprises a second half of the mark in the X direction.

15. The method of claim 14 wherein:
the first half of a mark extends into a second band; and
the second half of the mark extends into a third band.

16. The method of claim 14 wherein:
the first half and the second half of each mark are contiguous.

17. The method of claim 11 wherein:
neighboring bands are printed by combinations of rows that have at least one row in common.

18. The method of claim 11 wherein:
the test pattern repeats in the Y direction at a first frequency; and
each band of the test pattern includes a combination of mark and empty space that repeats in the X direction at a second frequency that is higher than the first frequency.

19. The method of claim 11 wherein:
the first row and the second row are separated in the Y direction by at least one other row.

20. The method of claim 11 further comprising:
holding printheads of the marking engine stationary as the test pattern is printed.

21. A non-transitory computer readable medium embodying programmed instructions which, when executed by a processor, are operable for performing a method comprising:
selecting a marking engine comprising rows of nozzles that eject ink onto a print medium, wherein the rows are separated from each other along a Y direction, and each row of nozzles extends in an X direction that is in-plane with the Y direction; and
directing the marking engine to print multiple bands of a test pattern, wherein each band is printed by:
selecting nozzles in a first row at regularly spaced intervals;
selecting nozzles in a second row that occupy adjacent X positions to the selected nozzles of the first row; and
ejecting continuous lines of ink from the selected nozzles in the first row and the selected nozzles in the second row onto a print medium to form a band comprising multiple evenly spaced marks separated by empty space, each mark comprising a first continuous line from a nozzle in the first row and a second continuous line from a nozzle in the second row, at least a portion of the second continuous line shares Y coordinates with at least a portion of the first continuous line, and

each band of the test pattern is printed by ejecting ink from nozzles in a different combination of nozzles.

Assignees

• Manchester William Edward
• Stanich Mikel John
• Ricoh Co Ltd

Inventors

• Manchester William Edward
• Stanich Mikel John

Classifications

• B41J2/04536

  using history data · CPC title

• B41J29/393 Primary

  Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} · CPC title

• B41J2/04586

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

• B41J2/2146

  for line print heads · CPC title

• B41J2/15 Primary

  for serial printing · CPC title