Claims
- 1. An ink-jet test pattern for determining printhead alignment error correction values for an ink-jet hard copy apparatus, said pattern comprising:
on a single sheet of A-size print media, optically readable, individually spaced test pattern objects arranged to form a plurality of regions on said print media including a first region for acquiring reflectance value data indicative of x-axis error correction values, a second region for acquiring reflectance value data indicative of y-axis error correction values, a third region for acquiring reflectance value data indicative of error correction values in column-to-column spacing nozzle sets firing a same color ink from different nozzle columns of an individual printhead, a fourth region for acquiring reflectance value data indicative of primitive-by-primitive error correction values, and a fifth region for acquiring reflectance value data indicative of bidirectional, variable speed printing x-axis error correction values.
- 2. The ink-jet test pattern as set forth in claim 1, wherein said first region further comprises:
a series of test pattern objects printed in rows such that objects are offset by cyclical errors induced by pen carriage motion during x-axis pen scanning.
- 3. The ink-jet test pattern as set forth in claim 2, further comprising:
first color inked objects as reference test pattern objects and having alternating first color inked objects and second color inked objects in a first subregion of said first region, first color inked objects and third color inked objects a second subregion of said first region, and first color inked objects to black inked objects in a third subregion of said first region.
- 4. The ink-jet test pattern as set forth in claim 1, wherein said second region further comprises:
first color inked objects as reference test pattern objects and having alternating first color inked objects with second color inked objects in a first subregion of said second region wherein print media is stepped in said y-axis between printing said first color inked objects and said second color inked objects, first color inked objects and third color inked objects a second subregion of said second region wherein print media is stepped in said y-axis between printing said first color inked objects and said third color inked objects, and first color inked objects to black objects in a third subregion of said second region wherein print media is stepped in said y-axis between printing said first color inked objects and said black inked objects.
- 5. The ink-jet test pattern as set forth in claim 1, wherein said third region further comprises:
at least one row of objects printed individually in each color ink and black ink wherein every other object of a row is printed with a different column of inking nozzles, firing the full column of inking nozzles for that color inked object.
- 6. The ink-jet test pattern as set forth in claim 1, wherein said fourth region further comprises:
at least one row of objects printed individually in each color ink and black ink wherein said objects alternate between objects printed from different primitives of the same ink and objects printed by firing all nozzles for that color inked object.
- 7. The ink-jet test pattern as set forth in claim 6, further comprising:
objects printed from different primitives are printed by stepping in a y-axis a distance equal to 1/N times a printhead nozzle column height (1/N×column height) per scan for “Np” passes, where Np=number of primitives in a printhead for that color ink.
- 8. The ink-jet test pattern as set forth in claim 1, wherein said fifth region further comprises:
at least one row of objects of each color ink and of black ink in which every other object is printed in the opposite scanning direction.
- 9. The ink-jet test pattern as set forth in claim 8, further comprising:
a repetition of a pattern of objects in said fifth region for each ink-jet hard copy apparatus scanning speed.
- 10. The ink-jet test pattern as set forth in claim 8, further comprising:
a pattern of objects in said fifth region printed for said ink-jet hard copy apparatus slowest scanning speed, and a repetition of said pattern of objects in said fifth region printed for said ink-jet hard copy apparatus highest scanning speed.
- 11. The ink-jet test pattern as set forth in claim 1, comprising:
a partial test pattern print printed only for said first region, second region, third region, fourth region and fifth region based on changed printheads only.
- 12. A method for aligning ink-jet printheads in a hard copy apparatus having a scanning carriage with a plurality of ink-jet pens mounted therein, each of said pens having a printhead, each of said printheads having a plurality of ink drop firing nozzles, and a printhead ink-jet nozzle-firing algorithm, comprising the steps of:
printing a test pattern on a single sheet of A-size print media, said test pattern including repetitious pairs of colored test objects; optically measuring actual offsets between the objects of each pair wherein offsets are indicative of respective printhead alignment aspects, including x-axis, y-axis, and z-axis alignments; calculating at least one printhead alignment error correction factor from said actual offsets; and providing a printhead alignment error correction factor to said nozzle-firing algorithm.
- 13. The method as set forth in claim 12, said step of printing further comprising the steps of:
printing a first region for acquiring reflectance value data indicative of x-axis error correction values, printing a second region for acquiring reflectance value data indicative of y-axis error correction values, printing a third region for acquiring reflectance value data indicative of error correction values in column-to-column spacing nozzle sets firing a same color ink from different nozzle columns of an individual printhead, printing a fourth region for acquiring reflectance value data indicative of primitive-by-primitive error correction values, and printing a fifth region for acquiring reflectance value data indicative of bidirectional, variable speed printing x-axis error correction values.
- 14. The method as set forth in claim 13, said step of printing a first region comprising the steps of:
printing repetitious pairs of colored objects having an irregular spacing.
- 15. The method as set forth in claim 14, said step of printing further comprising:
printing a pattern of repeated cyclic alternating color blocks having a printed pitch, “P,” matched to a vibration frequency of the scanning carriage.
- 16. The method as set forth in claim 14, said step of printing repetitious pairs of colored objects having an irregular spacing further comprising:
printing a pattern having a spacing including skipping half a block print cycle.
- 17. The method as set forth in claim 14, said step of printing repetitious pairs of colored objects having an irregular spacing further comprising:
printing a pattern in which the block cycle spacing is randomly or pseudo-randomly varied along the row.
- 18. The method as set forth in claim 14, said step of printing repetitious pairs of colored objects having an irregular spacing further comprising:
printing a pattern in which object spacing is set to avoid specific predetermined dynamic carriage-induced errors.
- 19. The method as set forth in claim 13, said step of printing said first region further comprising:
printing a pattern as a reference row all with a same set of nozzles from one printhead with spacing between the two members of each pair of objects in said pattern having a predetermined frequency.
- 20. A computer memory for calculating factors for aligning ink-jet printheads in a hard copy apparatus having a scanning carriage with a plurality of ink-jet pens mounted therein, each of said pens having a printhead, each of said printheads having a plurality of ink drop firing nozzles, and a printhead ink-jet nozzle-firing algorithm, comprising:
means printing a test pattern on a single sheet of A-size print media, said test pattern including repetitious pairs of colored test objects; means for storing optically measured actual offsets between the objects of each pair wherein offsets are indicative of respective printhead alignment aspects, including x-axis, y-axis, and z-axis, alignments; and means for calculating at least one printhead alignment error correction factor from said actual offsets.
- 21. The computer memory set forth in claim 20, comprising:
means for printing a first region for acquiring reflectance value data indicative of x-axis error correction values, means for printing a second region for acquiring reflectance value data indicative of y-axis error correction values, means for printing a third region for acquiring reflectance value data indicative of error correction values in column-to-column spacing nozzle sets firing a same color ink from different nozzle columns of an individual printhead, means for printing a fourth region for acquiring reflectance value data indicative of primitive-by-primitive error correction values, and means for printing a fifth region for acquiring reflectance value data indicative of bidirectional, variable speed printing x-axis error correction values.
RELATED APPLICATIONS
[0001] The present application is related to U.S. patent application Ser. No. ______, filed on the same date herewith, by the same inventors for an AUTOMATED INK-JET PRINTHEAD ALIGNMENT SYSTEM, attorney docket no. 10981087-1.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09263962 |
Mar 1999 |
US |
Child |
10052986 |
Nov 2001 |
US |