Systems and methods for degassing fluid

Patent metadata

Field	Value
Publication number	US-9776422-B2
Application number	US-201615379730-A
Country	US
Kind code	B2
Filing date	Dec 15, 2016
Priority date	Apr 29, 2011
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

Systems and methods for degassing fluid are disclosed. An example fluid ejection device including a channel having an entrance and an exit; a supply slot in communication with the channel; a vent; a first bubble impeding structure at the entrance of the channel; and a second bubble impeding structure at an exit of the channel, the first and second bubble impeding structures to retain a bubble within the channel to enable the bubble to be vented through a vent and to deter the bubble from entering the ink supply slot.

First claim

What is claimed is:

1. A fluid degassing unit for a printhead, the unit comprising:
an elongated recirculation path for providing fluid to the printhead and receiving unused fluid back from the printhead;
an ejection chamber with a firing element and a nozzle, the ejection chamber being in the recirculation path to selectively eject drops of fluid;
a controller to operate the firing element as a nucleation site to form gas bubbles during a degassing operation; and
a structure to impede gas bubbles formed at the nucleation site from moving through the recirculation path such that gas bubbles are vented through the nozzle.

2. The fluid degassing unit of claim 1 , further comprising a degas module implemented by the controller to form the nucleation site by operating the firing element at less than a turn-on-energy (TOE).

3. The fluid degassing unit of claim 2 , wherein the controller, when implementing the degas module, sends energy pulses of less than the TOE to the firing element.

4. The fluid degassing unit of claim 1 , wherein the elongated recirculation path has an input and an output for communicating fluidly with a fluid reservoir.

5. The fluid degassing unit of claim 1 , further comprising a pump element to pump fluid through the recirculation path.

6. The fluid degassing unit of claim 5 , the pump element to pump fluid through the recirculation path, under control of the controller, during the degassing operation and move gas bubbles, causing the gas bubbles to exit the nozzle.

7. The fluid degassing unit of claim 1 , wherein the recirculation path comprises a plurality of U-shaped sections, each U-shaped section comprising an ejection chamber with a firing element and a nozzle, the controller to selectively operate each firing element as a nucleation site during the degassing operation.

8. The fluid degassing unit of claim 7 , wherein the structure to impede gas bubbles comprises an impeding structure at each end of each U-shaped section.

9. The fluid degassing unit of claim 1 , wherein the structure to impede gas bubbles comprises two physical obstructions spaced apart to permit fluid, but not gas bubbles to pass.

10. A fluid degassing unit for a printhead, the unit comprising:
an electronic controller to receive data from a host device and, using the data, selectively energize a firing element in each of a plurality of ejection chambers to eject drops of fluid through a nozzle of each ejection chamber;
a degas module in a memory component of the electronic controller, the degas module to, when implemented by the controller during a degassing operation, cause the controller to operate any of the firing elements as a nucleation site to form gas bubbles that are vented through a nozzle.

11. The fluid degassing unit of claim 10 , wherein the degas module causes the controller to form the nucleation site by operating a firing element at less than a turn-on-energy (TOE).

12. The fluid degassing unit of claim 10 , wherein the controller, when implementing the degas module, sends energy pulses of less than a turn-on-energy (TOE) to a firing element.

13. The fluid degassing unit of claim 10 , the controller further to operate a pump element to pump fluid through a recirculation path that includes the ejection chambers.

14. The fluid degassing unit of claim 13 , the controller to operate the pump element to pump fluid through the recirculation path during the degassing operation so as to move gas bubbles, causing the gas bubbles to exit a nozzle.

15. A fluid degassing unit for a fluid ejection device, the unit comprising:
a fluid circulation path;
an ejection chamber with a firing element and a nozzle, the ejection chamber being in the fluid circulation path to selectively eject drops of fluid;
a controller to operate the firing element as a nucleation site to form gas bubbles during a degassing operation;
a degas module, implemented by the controller, to form the nucleation site by operating the firing element at less than a turn-on-energy (TOE); and
a structure to impede gas bubbles formed at the nucleation site from moving through the circulation path such that gas bubbles are vented through the nozzle.

16. The fluid degassing unit of claim 15 , wherein the controller, when implementing the degas module, sends a series of energy pulses of less than the TOE to the firing element.

17. The fluid degassing unit of claim 15 , further comprising a pump element, under control of the controller, to pump fluid through the circulation path.

18. The fluid degassing unit of claim 17 , the pump element to pump fluid through the circulation path during the degassing operation and move gas bubbles, causing the gas bubbles to exit the nozzle.

19. The fluid degassing unit of claim 15 , wherein the structure to impede gas bubbles comprises two physical obstructions spaced apart to permit fluid, but not gas bubbles to pass.

20. The fluid degassing unit of claim 19 , wherein the two physical obstructions are spaced apart by 1 to 10 microns.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Govyadinov Alexander

Classifications

• B41J2/19 Primary

  for removing air bubbles · CPC title

• B41J2002/14169

  Bubble vented to the ambience · CPC title

• B41J2/1404

  Geometrical characteristics · CPC title

• B41J2/18

  Ink recirculation systems · CPC title

• B41J2/14032

  Structure of the pressure chamber · CPC title