Nozzle condition evaluation

Patent metadata

Field	Value
Publication number	US-9776394-B2
Application number	US-201415306028-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	Apr 25, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

The present subject matter relates to evaluating nozzle condition of a plurality of nozzles. In one example, drive bubble detect (DBD) test results for a set of nozzles from among the plurality of nozzles are stored by a print head in a test result register, where the test result register is provided onto the print head. Further, status bits of a result-ready register provided in the print head are set to a predetermined value by the print head responsive to storing of the DBD test results in the test result register. Further, based on the setting, the DBD test results are obtained by a control unit, from the test result register, for evaluating the nozzle condition.

First claim

We claim:

1. A method for evaluating nozzle condition of a plurality of nozzles, the method comprising:
storing, by a print head, drive bubble detect (DBD) test results for a set of nozzles from among the plurality of nozzles in a test result register, wherein the test result register is provided onto the print head;
setting, by the print head, status bits of a result-ready register to a predetermined value provided in the print head responsive to storing of the test result register; and
obtaining, by a control unit, the DBD test results from the test result register, based on the setting, for evaluating the nozzle condition.

2. The method as claimed in claim 1 , wherein the method further comprises:
resetting, by the control unit, the status bits of the result-ready register to indicate transfer of the DBD test results from the test result register to a printer memory; and
initiating, by the print head, another set of nozzles from among the plurality of nozzles for performing DBD tests for evaluating the nozzle condition.

3. The method as claimed in claim 1 , wherein the storing further comprises
determining, by the print head, a nozzle, from among the set of nozzles, having the DBD test result as fail;
storing the DBD test result for the nozzle in the test result register; and
updating a nozzle count register to indicate the nozzle for which the DBD test result is being stored in the test result register.

4. The method as claimed in claim 3 , wherein the method further comprises updating a test complete register to indicate completion of DBD testing for the plurality of nozzles.

5. The method as claimed in claim 1 , wherein the method further comprises:
receiving, by the print head, a DBD testing command from the control unit for initiating DBD testing for the plurality of nozzles; and
performing, by the print head, DBD tests for the set of nozzles.

6. The method as claimed in claim 5 , wherein the performing further comprises:
resetting, by the print head, at least the result-ready register and the test result register upon receiving the DBD testing command; and
updating, by the print head, status of a fire data register to a predetermined value to initiate DBD test for a corresponding nozzle from among the plurality of nozzles.

7. A print head of a printer, the print head comprising:
a plurality of nozzles;
a test result register for storing drive bubble detect (DBD) test results performed for the plurality of nozzles;
a nozzle count register to indicate nozzles from among the plurality of nozzles for which the DBD test results are being stored in the test result register; and
a DBD module communicatively coupled to the plurality of nozzles, wherein the DBD module is to,
determine a nozzle, from among the plurality of nozzles, having the DBD test result as fail;
store the DBD test result for the nozzle in the test result register for being used by a control unit of the printer for evaluating nozzle condition of the nozzle based on the DBD test result; and
update a nozzle count register to indicate the nozzle for which the DBD test result is being stored in the test result register.

8. The print head as claimed in claim 7 further comprising a result-ready register for indicating status of the test result register, wherein the status is at least one of containing DBD test results and not containing DBD test results.

9. The print head as claimed in claim 8 , wherein the DBD module is to further,
set status bits of the result-ready register, provided in the print head, to a predetermined value responsive to storing of the DBD test results in the test result register to indicate storing of the DBD test results to the control unit of the printer for evaluating the nozzle condition of the nozzle based on the DBD test results.

10. The print head as claimed in claim 7 further comprising a test complete register to indicate completion of DBD testing for the plurality of nozzles.

11. The print head as claimed in claim 7 , wherein the DBD module is to further,
receive a DBD testing command from the control unit for initiating the DBD testing for the plurality of nozzles;
reset at least the nozzle count register, a result-ready register, a test complete register, and the test result register upon receiving the DBD testing command; and
update status of a fire data register to a predetermined value to initiate DBD test for the corresponding nozzle from among the plurality of nozzles.

12. A printer comprising:
a print head comprising
a plurality of nozzles; and
a drive bubble detect (DBD) module communicatively coupled to the plurality of nozzles, wherein the DBD module is to,
store DBD test results performed for a set of nozzles from among the plurality of nozzles in a test result register provided in the print head; and
set status bits of a result-ready register, provided in the print head, to a predetermined value responsive to storage of the DBD test results in the test result register; and

a control unit communicatively coupled to the print head to obtain the DBD test results from the test result register, based on the status bits, for evaluating nozzle condition of the set of nozzles.

13. The printer as claimed in claim 12 , wherein the print head further comprising,
the test result register for storing the DBD test results; and
the result-ready register for indicating status of the test result register, wherein the status is at least one of containing DBD test results and not containing DBD test results.

14. The printer as claimed in claim 12 , wherein
the control unit resets the status bits of the result-ready register to indicate transfer of the DBD test results from the test result register to a printer memory; and
the DBD module initiates another set of nozzles from among the plurality of nozzles for performing DBD tests for evaluating the nozzle condition.

15. The printer as claimed in claim 12 , wherein the DBD module is to further,
determine a nozzle, from among the set of nozzles, having the DBD test result as fail;
store the DBD test result for the nozzle in the test result register; and
update a nozzle count register to indicate the nozzle for which the DBD test result is being stored in the test result register.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Anderson Daryl E
• Martin Eric T

Classifications

• B41J2/0458

  controlling heads based on heating elements forming bubbles · CPC title

• B41J29/38

  Drives, motors, controls or automatic cut-off devices for the entire printing mechanism · CPC title

• B41J2/0451 Primary

  for detecting failure, e.g. clogging, malfunctioning actuator · CPC title

• B41J2/04555

  detecting current · CPC title

• B41J2/2142

  Detection of malfunctioning nozzles (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579) · CPC title