Claims
- 1. A method of printing an image from image data, using plural pens that in general are not perfectly aligned; said method comprising the steps of:
determining pen-to-pen mechanical misalignment; based on the determined misalignment, automatically shifting the data to compensate for at least a portion of the determined misalignment; and automatically printing with the shifted data.
- 2. The method of claim 1, wherein:
if the determining step establishes that the pens are aligned within a dot row, then the printing step prints without shifting the data.
- 3. The method of claim 1, wherein:
said plural pens print respective plural kinds of ink.
- 4. The method of claim 3, wherein:
said plural kinds of ink comprise plural ink colors respectively.
- 5. The method of claim 3, wherein:
said plural kinds of ink comprise plural ink dilutions respectively.
- 6. The method of claim 3, for use in printing said image onto a particular printing medium; and wherein:
the printing medium is substantially insensitive to relative timing of application of the plural kinds of ink respectively.
- 7. The method of claim 6, wherein:
the printing medium is plain paper
- 8. The method of claim 3, for use in printing said image onto a particular printing medium; and wherein:
the printing medium is sensitive to relative timing of application of the plural kinds of ink respectively; and the shifting step compensates for only part of the determined misalignment.
- 9. The method of claim 8, further comprising the step of:
employing pen-nozzle selections to compensate for at least part of a remainder of the determined misalignment.
- 10. The method of claim 1, wherein:
the shifting step compensates for all of the determined misalignment.
- 11. A printer for printing an image from image data; said printer comprising:
plural printheads each having a multiplicity of marking elements, each element being subject to deterioration and shortening of operable life through use; said plural printheads being subject to mechanical misalignment; and means for extending the life of the marking elements and thereby the life of the printheads by distributing use of the marking elements over a maximum number of marking elements; said life-extending means comprising means for automatically shifting the data to compensate for at least a portion of the misalignment.
- 12. The printer of claim 11, wherein:
said life-extending means further comprise means for automatically determining said mechanical misalignment.
- 13. The printer of claim 12, wherein the alignment-determining means comprise:
alignment data encoded on the pens; and means for reading the encoded data.
- 14. The printer of claim 12, wherein the alignment-determining means comprise:
means for using the pens to print a test pattern; and means for reading the test pattern to determine the pen alignment therefrom.
- 15. A printer for printing an image from image data, and comprising:
plural pens, each pen having multiple nozzles, said plural pens in general not being perfectly aligned; means for determining pen-to-pen physical misalignment; and portions of a processor programmed to automatically print such image using substantially all of the multiple nozzles of all of the pens, taking into account the determined physical alignment.
- 16. The apparatus of claim 15, wherein:
said processor portions are programmed to provide a relative shift of data for the plural pens, to compensate for imperfect alignment of the pens.
- 17. The apparatus of claim 16, wherein:
each pen has a top end and a bottom end; said physical misalignment comprises relative displacement of the pens toward lower or higher positions; and said data shift comprises raising data for a lowest pen or lowering data for a highest pen, or both.
- 18. The apparatus of claim 15, wherein the determining means comprise:
alignment data encoded on the pens; and means for reading the encoded data.
- 19. The apparatus of claim 18, wherein the determining means further comprise:
carriage datum-point alignment calibration data ascertained at manufacture of the apparatus; and portions of a processor programmed to automatically take into account the carriage datum-point alignment calibration data.
- 20. The apparatus of claim 15, wherein the determining means comprise:
means for using the pens to print a test pattern; and means for reading the test pattern to determine the pen alignment therefrom.
- 21. The printer of claim 15, wherein the determining means comprise:
means for using the pens to eject test drops; and means for sensing the test drops to determine the pen alignment therefrom.
- 22. The printer of claim 21, wherein:
the pen-using means comprise portions of a processor programmed to control the pens to eject test drops; and the test-drop pattern sensing means comprise a shutter and a detector disposed in combination for detecting drops ejected from particular nozzles of the pen.
- 23. The printer of claim 22, wherein the detector comprises:
an optical drop detector.
RELATED PATENT DOCUMENTS
[0001] A closely related document is another, coowned U. S. utility-patent application filed in the United States Patent and Trademark Office substantially contemporaneously with this document—and also hereby incorporated by reference in its entirety into this document. It is in the names of Askeland et al., identified as Hewlett Packard Company docket number PD-10982150-1, and entitled “ADAPTIVE INCREMENTAL-PRINTING MODE THAT MAXIMIZES THROUGHPUT WHILE MAINTAINING INTERPEN ALIGNMENT BY NOZZLE SELECTION”—subsequently assigned utility-patent application Ser. No. 09/______, and ______, issued as U.S. Pat. No. 5,______ on ______, 200______.