Fluidic dies with selectors adjacent respective firing subassemblies

Patent metadata

Field	Value
Publication number	US-11312129-B2
Application number	US-201817267542-A
Country	US
Kind code	B2
Filing date	Nov 21, 2018
Priority date	Nov 21, 2018
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

In one example in accordance with the present disclosure, a fluidic die is described. The fluidic die includes an array of firing subassemblies grouped into zones. Each firing subassembly includes 1) a firing chamber, 2) a fluid actuator, and 3) a sensor plate. The fluidic die also includes a measurement device per zone to measure a voltage indicative of an impedance within a selected firing chamber. The fluidic die includes a selector per firing subassembly to couple a selected sensor plate to the measurement device. A selector is adjacent a respective firing subassembly and a distance between the selector and the measurement device is different as compared to other selectors.

First claim

What is claimed is:

1. A fluidic die, comprising:
an array of firing subassemblies grouped into zones, each firing subassembly comprising:
a firing chamber;
a fluid actuator disposed within the firing chamber; and
a sensor plate disposed within the firing chamber;

a measurement device per zone to measure a voltage indicative of an impedance within a selected firing chamber; and
a selector per firing subassembly to couple a selected sensor plate to the measurement device, wherein:
each selector is adjacent a respective firing subassembly; and
a distance between the selector and the measurement device is different as compared to at least one other selector.

2. The fluidic die of claim 1 , wherein the measurement device:
forces a current onto the sensor plate associated with the selected firing subassembly; and
receives a signal indicative of an impedance within the selected firing chamber.

3. The fluidic die of claim 2 , wherein the measurement device measures the signal indicative of the impedance after a predetermined period of time after forcing the current onto the sensor plate.

4. The fluidic die of claim 1 , wherein a distance between the selector and its associated sensor plate is the same as compared to other selectors.

5. The fluidic die of claim 1 , wherein:
a parasitic capacitance between each selector and a respective firing subassembly is uniform; and
a parasitic capacitance between each selector and the measurement device is seen by all selectors.

6. The fluidic die of claim 1 , wherein a node between the measurement device and the selector is shared between each firing subassembly in the zone.

7. The fluidic die of claim 1 , further comprising a pull-down transistor per firing subassembly.

8. The fluidic die of claim 7 , wherein the pull-down transistor is adjacent a respective firing subassembly.

9. The fluidic die of claim 7 , wherein the pull-down transistor is between a respective selector and firing subassembly.

10. The fluidic die of claim 1 , wherein the sensor plate is a drive bubble detector to detect the presence of a drive bubble in the firing chamber.

11. The fluidic die of claim 1 , wherein:
the sensor plate is to output different impedance measurements over time of a bubble formation in the firing chamber; and
the measurement device compares each impedance measurement against a different threshold.

12. The fluidic die of claim 1 , wherein a spacing between the selector and the respective firing subassembly is selected based on a target parasitic capacitance.

13. A fluidic die, comprising:
an array of firing subassemblies grouped into zones wherein:
the array comprises an angled column of firing subassemblies; and
each firing subassembly comprises:
a firing chamber;
a fluid actuator disposed within the firing chamber; and
a sensor plate disposed within the firing chamber;

a measurement device per zone to measure a voltage indicative of an impedance within a selected firing chamber; and
a selector per firing subassembly to couple a selected sensor plate to the measurement device, wherein:
the selector is adjacent a respective ejection subassembly;
a parasitic capacitance along a path between each respective sensor plate and selector is uniform;
a distance between the selector and the measurement device is different as compared to at least one other selector; and
a distance between the selector and its associated sensor plate is the same as compared to other selectors.

14. The fluidic die of claim 13 , wherein distances between each firing subassembly and the measurement device increases going along the angled column.

15. The fluidic die of claim 13 , wherein a shortest distance between a first firing subassembly and the measurement device is at least ten times shorter than a longest distance between a second firing subassembly and the measurement device.

16. The fluidic die of claim 13 , wherein the measurement device is coupled to each selector such that parasitic capacitance between each selector and the measurement device is shared.

17. The fluidic die of claim 13 , wherein the measurement device outputs a signal by which a firing subassembly health is determined.

18. A fluidic system comprising:
a fluidic die, comprising:
an array of firing subassemblies grouped into zones, each firing subassembly comprising:
a firing chamber;
a fluid actuator disposed within the firing chamber; and
a sensor plate disposed within the firing chamber;

a measurement device per zone to measure a voltage indicative of an impedance within a selected firing chamber; and
a selector per firing subassembly to couple a selected sensor plate to the measurement device, wherein:
the selector is adjacent a respective firing subassembly; and
a distance between the selector and the measurement device is different as compared to at least one other selector; and

a controller to, based on an output of the measurement device, determine a state of a selected firing subassembly.

19. The fluidic system of claim 18 , wherein the controller is disposed off the fluidic die.

20. The fluidic system of claim 18 , wherein each selector is positioned relative to the respective firing subassembly such that a parasitic capacitance between the selector and respective sensor is less than a predetermined amount.

Assignees

• Hewlett Packard Development Co

Inventors

• Martin Eric
• Przybyla James R
• Anderson Daryl E

Classifications

• B41J2/0455

  Details of switching sections of circuit, e.g. transistors · CPC title

• B41J2/14153 Primary

  Structures including a sensor · CPC title

• B41J2/04555 Primary

  detecting current · CPC title

• B41J2/0458

  controlling heads based on heating elements forming bubbles · CPC title

• B41J2/04541

  Specific driving circuit · CPC title