Print apparatus maintenance

Patent metadata

Field	Value
Publication number	US-12403695-B2
Application number	US-202118557635-A
Country	US
Kind code	B2
Filing date	Apr 28, 2021
Priority date	Apr 28, 2021
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A print apparatus is disclosed. The print apparatus comprises a print fluid application unit having a plurality of nozzles through which print fluid is to be deposited onto a printable medium during a printing operation. The print apparatus also comprises a nozzle cleaning surface to engage nozzles during a nozzle cleaning operation. The print apparatus also comprises a scanning unit and a controller. The controller is to control the print fluid application unit to deposit print fluid from nozzles of the plurality of nozzles according to an intended pattern onto the nozzle cleaning surface; control the scanning unit to scan the pattern formed on the nozzle cleaning surface; and responsive to determining, based on the scan, that print fluid from a nozzle of the plurality of nozzles has not been deposited according to the intended pattern, generate an instruction signal regarding maintenance of the print fluid application unit. A method and a machine-readable medium are also disclosed.

First claim

The invention claimed is:

1. A print apparatus comprising:
a print fluid application unit having a plurality of nozzles through which print fluid is to be deposited onto a printable medium during a printing operation;
a nozzle cleaning surface to engage nozzles during a nozzle cleaning operation;
a scanning unit; and
a controller to:
control the print fluid application unit to deposit print fluid from nozzles of the plurality of nozzles according to an intended pattern onto the nozzle cleaning surface;
control the scanning unit to scan the pattern formed on the nozzle cleaning surface; and
responsive to determining, based on the scan, that print fluid from a nozzle of the plurality of nozzles has not been deposited according to the intended pattern, generate an instruction signal regarding maintenance of the print fluid application unit.

2. A print apparatus according to claim 1 , wherein the scanning unit and the print fluid application unit are movable relative to the printable medium in a synchronous manner.

3. A print apparatus according to claim 1 , further comprising:
a carriage coupled to the print fluid application unit and the scanning unit, the carriage to move over the printable medium and the nozzle cleaning surface.

4. A print apparatus according to claim 1 , wherein the scanning unit comprises an optical sensor to detect deposits of print fluid formed on the nozzle cleaning surface by nozzles of the plurality of nozzles.

5. A print apparatus according to claim 1 , wherein the nozzle cleaning surface comprises a web of material; and
wherein the controller is to:
generate an instruction signal to advance the web of material, responsive to determining, based on the scan, that a defined threshold amount of print fluid has been deposited onto a portion of the nozzle cleaning surface onto which the print fluid is to be deposited.

6. A print apparatus according to claim 1 , wherein the nozzle cleaning surface comprises a web of material; and
wherein the controller is to:
generate an alert signal, responsive to determining, based on the scan, that an amount of print fluid that has been deposited onto the nozzle cleaning surface meets or exceeds a defined threshold amount.

7. A print apparatus according to claim 1 , wherein the instruction signal regarding maintenance of the print fluid application unit comprises a signal to cause the nozzle of the print fluid application unit to be wiped by the nozzle cleaning surface.

8. A method comprising:
instructing the delivery, from a plurality of nozzles of a print head, of print agent in accordance with an assessment pattern onto a nozzle wiping surface of a print apparatus;
scanning the printed assessment pattern with an image scanner to generate a scanned assessment image;
determining, from the scanned assessment image, whether any of the nozzles of the plurality of nozzles failed to deliver print agent in accordance with the assessment pattern; and
performing corrective action if it is determined that a particular nozzle of the plurality of nozzles has failed to deliver print agent in accordance with the assessment pattern.

9. A method according to claim 8 , wherein the assessment pattern comprises a discrete deposit of print agent from each nozzle of the plurality of nozzles.

10. A method according to claim 8 , wherein the corrective action comprises an action selected from a group comprising: providing a notification for delivery to an operator of the print apparatus; performing or scheduling a nozzle wiping operation in respect of the particular nozzle; performing a realignment action in respect of the particular nozzle; deactivating the particular nozzle; arranging for a different nozzle to deliver print agent instead of the particular nozzle; and arranging for the print apparatus to halt printing.

11. A method according to claim 8 , further comprising:
determining, from the scanned assessment image, an indication of an amount of print agent on the nozzle wiping surface;
responsive to determining that the amount of print agent on the nozzle wiping surface meets or exceeds threshold amount, generating a notification signal.

12. A method according to claim 8 , wherein the print head comprises a first subset of nozzles and a second subset of nozzles;
wherein the plurality of nozzles forms the first subset of nozzles; and
wherein said instructing comprises instructing the delivery of print agent from the first subset of nozzles and not from the second subset of nozzles.

13. A method according to claim 8 , wherein said instructing comprises instructing the delivery of print agent onto the nozzle wiping surface at a time coinciding with a planned nozzle wiping operation associated with the print head.

14. A machine-readable medium comprising instructions which, when executed by a processor, cause the processor to:
operate a print agent applicator to eject print agent onto a wiping medium according to a defined pattern in which print agent is intended to be ejected from each nozzle of a plurality of nozzles of the print agent applicator to form a discrete patch of print agent on the wiping medium;
receive, from a sensor, data indicative of whether or not each nozzle of the plurality of nozzles ejected print agent onto the wiping medium in accordance with the defined pattern; and
responsive to determining that a nozzle of the plurality of nozzles did not eject print agent onto the wiping medium in accordance with the defined pattern, generating an alert signal.

15. A machine-readable medium according to claim 14 , wherein the generated alert signal comprises a signal to control the print agent applicator to perform a wiping operation whereby the nozzle of the plurality of nozzles is wiped by the wiping medium.

Assignees

• Hewlett Packard Development Co

Inventors

• Cessel Gianni
• Carmona Calpe Carles
• Casaldaliga Albisu Marcos
• Mena Rodriguez Pablo Carmelo
• Abello Rosello Lluis
• Velazquez Gomez Ma Pilar
• Silvestre Ricard
• Verges Llahi Jaume
• Vazquez Fernandez Dorkaitz Alain
• Torrents Barrena Jordina
• Bordone Maurizio

Classifications

• B41P2235/20

  Wiping devices · 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

• B41J2/2139

  Compensation for malfunctioning nozzles creating dot place or dot size errors (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045) · CPC title

• B41J2/16535

  using wiping constructions (B41J2/16552 takes precedence) · CPC title

• B41J2/04586

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