Print head nozzle spitting

Patent metadata

Field	Value
Publication number	US-2021283906-A1
Application number	US-201716337751-A
Country	US
Kind code	A1
Filing date	Jan 27, 2017
Priority date	Jan 27, 2017
Publication date	Sep 16, 2021
Grant date	—

Abstract

A method is disclosed. The method may involve obtaining information indicative of a number of printing passes of a print head to print a swath on a printable medium. The method may comprise determining that the print head is to perform a particular printing pass which is one of: a printing pass during which an amount of print agent to be deposited from nozzles of the print head differs, by an amount that exceeds a defined threshold, from an amount of print agent to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and a printing pass to print a swath which is the first of a plurality of adjacent swaths in which each swath has an area coverage exceeding a defined threshold. The method may comprise preparing, based on said obtained information, a schedule for a nozzle spitting procedure to commence before the print head performs the particular printing pass.

First claim

1 . A method comprising:
obtaining information indicative of a number of printing passes of a print head to print a swath on a printable medium; determining that the print head is to perform a particular printing pass which is one of:
a printing pass during which an amount of print agent to be deposited from nozzles of the print head differs, by an amount that exceeds a defined threshold, from an amount of print agent to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and
a printing pass to print a swath which is the first of a plurality of adjacent swaths in which each swath has an area coverage exceeding a defined threshold; and
preparing, based on said obtained information, a schedule for a nozzle spitting procedure to commence before the print head performs the particular printing pass.

2 . A method according to claim 1 , wherein the print head comprises a plurality of subsets of nozzles, and wherein said preparing a schedule comprises:
scheduling a first subset of the plurality of subsets of nozzles to spit a first amount of print agent prior to the particular printing pass; and scheduling a second subset of the plurality of subsets of nozzles to spit a second amount of print agent prior to the particular printing pass.

3 . A method according to claim 2 , wherein the first amount is different from the second amount.

4 . A method according to claim 2 , wherein the particular printing pass comprises a printing pass to print a swath which is the first of a plurality of adjacent swaths in which each swath has an area coverage exceeding a defined threshold; and
wherein the second amount is less than the first amount.

5 . A method according to claim 4 , wherein said preparing a schedule further comprises:
scheduling the first subset of the plurality of subsets of nozzles to spit a third amount of print agent after the particular printing pass, and prior to a printing pass immediately following the particular printing pass; and scheduling the second subset of the plurality of subsets of nozzles to spit a fourth amount of print agent after the particular printing pass, and prior to the printing pass immediately following the particular printing pass; wherein the third amount is less than the fourth amount.

6 . A method according to claim 5 , wherein the first amount is the same as the fourth amount, and the second amount is the same as the third amount.

7 . A method according to claim 2 , wherein the particular printing pass comprises a printing pass during which an amount of print agent to be deposited from nozzles of the print head differs, by an amount that exceeds a defined threshold, from an amount of print agent to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and
wherein the second amount is less than the first amount.

8 . A method according to claim 7 , wherein said preparing a schedule further comprises:
scheduling the first subset of the plurality of subsets of nozzles to spit a third amount of print agent after the particular printing pass, and prior to a printing pass immediately following the particular printing pass; and scheduling the second subset of the plurality of subsets of nozzles to spit a fourth amount of print agent after the particular printing pass, and prior to the printing pass immediately following the particular printing pass; wherein the third amount is the same as the fourth amount.

9 . A method according to claim 2 , wherein the particular printing pass comprises a printing pass during which an amount of print agent to be deposited from nozzles of the print head differs, by an amount that exceeds a defined threshold, from an amount of print agent to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and
wherein the first amount is less than the second amount.

10 . A method according to claim 9 , wherein said preparing a schedule further comprises:
scheduling the first subset of the plurality of subsets of nozzles to spit a third amount of print agent after the particular printing pass, and prior to a printing pass immediately following the particular printing pass; and scheduling the second subset of the plurality of subsets of nozzles to spit a fourth amount of print agent after the particular printing pass, and prior to the printing pass immediately following the particular printing pass; wherein the third amount is the same as the fourth amount.

11 . A method according to claim 1 , wherein said particular pass comprises one of a plurality of printing passes to be performed during a print job; and
wherein an amount of spitting to be performed during the nozzle spitting procedure is determined based on an amount of print agent to be deposited on the printable medium during the print job.

12 . A method according to claim 1 , further comprising:
performing said spitting procedure in accordance with said schedule.

13 . A method according to claim 12 , further comprising:
following said performing of said scheduled spitting procedure, spitting an equal amount of print agent from each of the plurality of subsets of nozzles.

14 . A print apparatus comprising:
a print agent distributor having a plurality of nozzles to deposit print agent onto a substrate during successive printing passes; and a processor to:
ascertain that the print head is to perform a particular printing pass which is one of:
a printing pass during which an amount of print agent to be deposited from nozzles of the print agent distributor differs, by an amount that exceeds a defined threshold, from an amount of print agent to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and
a printing pass to print a swath which is the first of a plurality of adjacent swaths in which each swath has an area coverage exceeding a defined threshold; and

devise a schedule for spitting print agent from the nozzles to commence before the print agent distributor performs the particular printing pass.

15 . A machine-readable medium comprising instructions which, when executed by a processor, cause the processor to:
receive data indicating of a number of printing passes of a print head to print a swath on a printable medium; ascertain that the print head is to perform a particular printing pass which is one of:
a printing pass during which a number of drops of ink to be deposited from nozzles of the print head differs, by an amount that exceeds a defined threshold, from a number of drops of ink to be deposited from the nozzles during a printing pass immediately preceding said particular printing pass; and
a printing pass to print a swath which is the first of a plurality of adjacent swaths in which each swath has an area coverage exceeding a defined threshold; and
prepare, based on said obtained information, a schedule for a nozzle spitting procedure to be commenced prior to the print head performing the particular printing pass.

Assignees

• Hewlett Packard Development Co

Inventors

• Gracia Verdugo Antonio
• Costal Fornells Pau
• Guillo Norman

Classifications

• B41J2/04586

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

• B41J2/165 Primary

  Prevention {or detection} of nozzle clogging, e.g. cleaning, capping or moistening for nozzles · CPC title

• B41J2/16526

  by applying pressure only · CPC title

• B41J2/17

  characterised by ink handling {(cleaning by driving a fluid through the nozzles to the outside thereof B41J2/1652; for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing B41J11/0015)} · CPC title

• B41J2/04533 Primary

  controlling a head having several actuators per chamber · CPC title