Printhead alignment correction

Patent metadata

Field	Value
Publication number	US-9676180-B2
Application number	US-201314787464-A
Country	US
Kind code	B2
Filing date	Aug 13, 2013
Priority date	Aug 13, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Herein, techniques are described for printing an image on a print media by operation of a printhead to eject a print fluid over the print media. In at least some examples, a printhead temperature parameter is acquired, the parameter being indicative of a temperature at the printhead during printing; alignment of the printhead is corrected based on the printhead temperature parameter; printing is performed on the print media via the printhead according to the corrected alignment.

First claim

What is claimed is:

1. A method for printing an image on a print media by operation of a printhead to eject a print fluid over the print media, comprising:
acquiring a printhead temperature parameter indicative of a temperature at the printhead during printing, wherein the printhead temperature parameter is a print fluid amount to be ejected by the printhead to print at least an image portion, the temperature at the printhead being correlated to the print fluid amount;
correcting alignment of the printhead based on the printhead temperature parameter; and
printing on the print media via the printhead according to the corrected alignment.

2. The method of claim 1 , wherein the printhead temperature parameter is a printhead temperature value acquired from a temperature sensor.

3. The method of claim 1 , wherein the correcting is performed for a set of nozzles in the printhead.

4. An inkjet printer for printing an image on a print media by operation of a printhead, the printer comprising:
a controller to control the printhead to print an image portion by causing, while an image is being printed:
acquisition of a printhead temperature parameter indicative of a temperature at the printhead, wherein the printhead temperature parameter is a print fluid amount to be ejected by the printhead to print at least an image portion, the temperature at the printhead being correlated to the print fluid amount;
correction of alignment of the printhead with respect to the print media based on the acquired printhead temperature parameter; and
printing the image portion by actuation of the printhead according to the corrected alignment.

5. The inkjet printer of claim 4 further comprising a temperature sensor for measuring a printhead temperature, the printhead temperature parameter corresponding to the sensor measurement.

6. The inkjet printer of claim 4 further comprising an engine providing a print fluid density counting function providing an estimate of the amount of print fluid to be ejected by the printhead to print the image portion, the printhead temperature parameter corresponding to values of the print fluid density counting function, the temperature at the printhead being correlated to the print fluid amount.

7. The inkjet printer of claim 6 , wherein the engine includes an application-specific integrated circuit module customized for providing the print fluid density counting function.

8. The inkjet printer of claim 4 , further including a memory including stored alignment parameters, the correction of alignment including accordingly modifying the stored alignment parameters.

9. A computer software product comprising a tangible medium readable by a processor, the medium having stored thereon a set of instructions for operating a printer for printing an image by operation of a printhead, the instructions comprising:
a set of instructions which, when loaded into a memory and executed by the processor, store an alignment setting for the printhead;
a set of instructions which, when loaded into a memory and executed by the processor, causes initializing alignment of the printhead based on the stored alignment setting;
a set of instructions which, when loaded into a memory and executed by the processor, causes acquiring of a printhead temperature parameter indicative of a temperature at the printhead while an image is being printed, wherein the printhead temperature parameter is a predictive temperature parameter comprising a print fluid amount to be ejected by the printhead for printing an outstanding image portion, the temperature at the printhead being correlated to the print fluid amount;
a set of instructions which, when loaded into a memory and executed by the processor, causes validating the stored alignment settings against the acquired printhead temperature parameter;
a set of instructions which, when loaded into a memory and executed by the processor, causes, modifying the stored alignment setting according to the validating; and
a set of instructions which, when loaded into a memory' and executed by the processor, causes printing the image portion according to the modified stored alignment setting.

10. The product of claim 9 , wherein the validating includes accessing a look-up table relating printhead temperature parameter values with alignment settings.

11. The product of claim 9 , wherein printhead alignment is to prevent a bidirectional dot placement error caused by a variation of printhead temperature.

12. The product of claim 9 , wherein the printhead temperature parameter is indicative of printhead temperature for printing the outstanding image portion.

13. The product of claim 9 , wherein the printhead temperature parameter is a sensor measurement indicative of an actual printhead temperature.

14. The method of claim 1 , wherein acquiring a printhead temperature parameter, and correcting alignment of the printhead are carried out multiple times during a printing of an image.

15. The method of claim 1 , wherein acquiring the printhead temperature parameter includes acquiring multiple printhead temperature parameters for a printhead.

16. The inkjet printer of claim 4 , wherein acquisition of a printhead temperature parameter and correction fo alignment of the printhead based on the acquired printhead temperature parameter are carried out for each portion of an image.

17. The inkjet printer of claim 4 , wherein the controller compensates for temperature variations during printing of an image.

18. The method of claim 1 , wherein correction of alignment of the printhead is applied just to print areas expected to have temperature increases.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Gracia Verdugo Antonio
• Kammerzell Barret
• Jorba Closa Joan Albert

Classifications

• B41J2/2135

  Alignment of dots · CPC title

• B41J2/365

  by compensation for variation in temperature · CPC title

• B41J25/001

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

• B41J2/04563

  detecting head temperature; Ink temperature · CPC title

• B41J2/04505 Primary

  aiming at correcting alignment · CPC title