Fluid drop detection in firing paths corresponding to nozzles of a printhead

Patent metadata

Field	Value
Publication number	US-9770904-B2
Application number	US-201214650168-A
Country	US
Kind code	B2
Filing date	Dec 10, 2012
Priority date	Dec 10, 2012
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A method of operating a printing system includes identifying groups of nozzles of a plurality of nozzles of a printhead device. The method also includes ejecting fluid drops by the printhead device from nozzles thereof and along corresponding firing paths. The method also includes controlling movement of a detector carriage including a plurality of drop detectors of a drop detector array with respect to the printhead device by a control module to align each one of the drop detectors with the respective firing paths corresponding to the respective nozzles at a predetermined time. The method also includes sensing the firing paths corresponding to the nozzles to detect a presence of the fluid drops by the drop detectors such that each one of the drop detectors senses at a same time a respective firing path corresponding to a respective nozzle for a plurality of groups of nozzles.

First claim

What is claimed is:

1. A printing system, comprising:
a printhead device including a plurality of nozzles, the printhead device to eject fluid drops from the nozzles and along corresponding firing paths, respectively;
a group identification module to identify groups of nozzles of the plurality of nozzles of the printhead device; and
a drop detector array including a plurality of drop detectors disposed adjacent to each other and a detector carriage coupled to the plurality of drop detectors;
the drop detectors to sense the firing paths corresponding to the nozzles to detect a presence of the fluid drops for the respective nozzles, wherein the groups of nozzles are spaced so that each one of the drop detectors is to sense, at a same time, a respective firing path corresponding to a respective nozzle for a different group of nozzles; and
the detector carriage and the printhead device to move with respect to each other, wherein a spacing between drop detectors corresponds to a spacing between different groups of nozzles such that the controlled movement of the detector carriage simultaneously aligns different drop detectors with nozzles from different groups of nozzles.

2. The printing system according to claim 1 , wherein each one of the drop detectors is spaced apart from each other in a first direction by a predetermined sensor spacing distance.

3. The printing system according to claim 2 , wherein the respective firing path corresponding to the respective nozzle for the plurality of groups of nozzles to be sensed at the same time is spaced apart from each other in the first direction by the predetermined sensor spacing distance.

4. The printing system according to claim 1 , further comprising: a control module to control movement of the detector carriage with respect to the printhead device to align each one of the drop detectors with the respective firing path corresponding to the respective nozzle for the plurality of groups of nozzles at a predetermined time.

5. The printing system according to claim 4 , wherein the control module is configured to control movement of the detector carriage at a constant speed in an orthogonal direction with respect to the firing paths corresponding to the nozzles and in synchronization with the fluid drops ejected from the nozzles.

6. The printing system according to claim 1 , wherein each of the plurality of groups of nozzles identified by the group identification module includes a number of nozzles equal to a number of the drop detectors.

7. The printing system according to claim 1 , further comprising: a determination module to determine a nozzle health status for the respective nozzles such that a respective nozzle is determined to be a healthy nozzle in response to a detection of a respective fluid drop in a respective firing path corresponding thereto and an unhealthy nozzle in response to a detection of an absence of a respective fluid drop in a respective firing path corresponding thereto by the drop detector array.

8. The printing system according to claim 1 , wherein each one of the plurality of drop detectors further comprises: a detector receiver; and a detector source spaced apart from the detector receiver, the detector source to emit a signal to the detector receiver to detect the presence of respective fluid drops passing through the signal.

9. The printing system according to claim 1 , wherein the printhead device further comprises: a print bar including a plurality of inkjet printhead modules disposed adjacent to each other, each one of the inkjet printhead modules including at least one printhead die having nozzles disposed thereon.

10. The printing system of claim 1 , wherein a group of nozzles consists of two nozzles.

11. The printing system of claim 1 , wherein a group of nozzles comprises a linear row of nozzles on the printhead device.

12. The printing system of claim 1 , wherein each group of nozzles comprises a number of nozzles equal to a number of the drop detectors of the drop detector array.

13. A method of operating a printing system, the method comprising:
identifying groups of nozzles of a plurality of nozzles of a printhead device by a group identification module;
ejecting fluid drops by the printhead device from nozzles thereof and along corresponding firing paths;
controlling movement of a detector carriage including a plurality of drop detectors of a drop detector array with respect to thee printhead device by a control module to align the drop detectors with respective firing paths corresponding to respective nozzles at a predetermined time, wherein a spacing between drop detectors corresponds to a spacing between different groups of nozzles such that the controlled movement of the detector carriage simultaneously aligns different drop detectors with nozzles from different groups of nozzles; and
sensing the respective firing paths corresponding to the respective nozzles to detect a presence of fluid drops by the drop detectors to determine a nozzle health status for the respective nozzles such that each one of the drop detectors senses at a same time a respective firing path corresponding to a respective nozzle for a plurality of groups of nozzles;
wherein the identifying groups of nozzles of a plurality of nozzles of a printhead device by a group identification module further comprises: identifying a number of nozzles corresponding to a number of the drop detectors for each of the plurality of the groups of nozzles.

14. The method according to claim 13 , wherein the controlling movement of a detector carriage further comprises: controlling movement of the detector carriage at a constant speed in an orthogonal direction with respect to the firing paths corresponding to the nozzles and in synchronization with the fluid drops ejected from the nozzles.

15. The method according to claim 13 , wherein the ejecting fluid drops by the printhead device from nozzles thereof and along corresponding firing paths further comprises:
ejecting fluid drops from a first set of nozzles including a corresponding nozzle from a first subset of the plurality of groups of nozzles at a predetermined time to coincide with the detector carriage arriving at a predetermined position; and
ejecting fluid drops from a second set of nozzles different than the first set of nozzles and including a corresponding nozzle from a second subset of the plurality of groups of nozzles at a subsequent predetermined time to coincide with the detector carriage arriving at a subsequent predetermined position.

16. The method according to claim 13 , further comprising: determining a respective nozzle to be a healthy nozzle by a determination module in response to a detection by the drop detector array of a respective fluid drop in a respective firing path corresponding thereto and an unhealthy nozzle in response to a detection an absence of a respective fluid drop in a respective firing path corresponding thereto.

17. A non-transitory computer-readable storage medium having computer executable instructions stored thereon to operate a printing system, the instructions are executable by a processor to direct:
a printhead device to eject fluid drops from nozzles thereof and along corresponding firing paths, the nozzles being assigned to respective group of nozzles;
a control module to control movement of a detector carriage including a plurality of drop detectors of a drop detector array with respect to the printhead device at a constant speed in an orthogonal direction with respect to the firing paths corresponding to the nozzles and in synchronization wi

Assignees

• Hewlett Packard Development Co Lp
• Hewlett Packard Development Co Lp

Inventors

• Portela Mata Laura
• Soriano Fosas David

Classifications

• B41J2/125 Primary

  Sensors, e.g. deflection sensors {(nozzle clogging detection for cleaning reasons B41J2/16579; detection for compensation for failed nozzles B41J2/2139)} · CPC title

• B41J29/393

  Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} · 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

• B41J2/0456 Primary

  detecting drop size, volume or weight · CPC title

• B41J2/04586

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