CIRCULATING FLUID FOR FLUID DROPLET EJECTING

• US 20110128335A1
• Filed: 04/30/2009
• Published: 06/02/2011
• Est. Priority Date: 05/23/2008
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: von Essen, Kevin, Bibl, Andreas, Hoisington, Paul A.
• Granted Patent: US 8,616,689 B2
• Time in Patent Office: Days
• US Class Current: 347/89
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/18 Ink recirculation systems
• CPC Class Codes: B41J 2202/12 with ink circulating through the whole print head

Abstract

A fluid droplet ejection apparatus includes a printhead having a fluid supply and a fluid return. A substrate is attached to the printhead, and the substrate includes a fluid inlet and a fluid outlet on a surface of the substrate proximate to the fluid supply and fluid return. Nozzles are in fluid communication with the fluid inlet. The fluid inlet of the substrate is in fluid communication with the fluid supply, and the fluid outlet is in fluid communication with the fluid return. A first circulation path through the substrate is between the fluid inlet and the fluid outlet. The fluid supply is in fluid communication with the fluid return through a second circulation path that is through the printhead and not through the substrate.

Claims

1. A fluid droplet ejection apparatus comprising:

a printhead having a fluid supply and a fluid return; and

a substrate attached to the printhead, the substrate having a fluid inlet and a fluid outlet on a surface of the substrate proximate to the fluid supply and the fluid return, and nozzles in fluid communication with the fluid inlet,

wherein the fluid inlet of the substrate is in fluid communication with the fluid supply and the fluid outlet is in fluid communication with the fluid return,

wherein a first circulation path through the substrate is between the fluid inlet and the fluid outlet, and

wherein the fluid supply is in fluid communication with the fluid return through a second circulation path that is through the printhead and not through the substrate.

2. The apparatus of claim 1, wherein the second circulation path is parallel to the first circulation path.

3. The apparatus of claim 1, wherein the second circulation path has a larger average cross-sectional area than the first circulation path.

4. The apparatus of claim 1, further comprising:

a filter positioned in the first circulation path, the second circulation path, or both.

5. The apparatus of claim 1, further comprising:

a temperature sensor in thermal communication with one or both of the first circulation path and the second circulation path.

6. The apparatus of claim 1, further comprising:

a fluid temperature control device in thermal communication with the first circulation path, the second circulation path, or both.

7. The apparatus of claim 1, further comprising:

a fluid supply tank in fluid communication with the fluid supply; and

a fluid return tank in fluid communication with the fluid return.

8. The apparatus of claim 7, further comprising:

a fluid supply pump in fluid communication with the fluid supply tank and the fluid return tank.

9. The apparatus of claim 8, wherein the fluid supply pump controls a difference in fluid height between the fluid supply tank and the fluid return tank.

10. The apparatus of claim 8, wherein the fluid supply pump controls a height of fluid in the fluid supply tank.

11. The apparatus of claim 8, wherein any fluid path between the supply pump and the substrate includes either the fluid supply tank or the fluid return tank or both.

12. The apparatus of claim 1, wherein the fluid supply is in fluid communication with the fluid return through a bypass circulation path that is different from the first circulation path and the second circulation path.

13. A method for fluid droplet ejection, comprising:

flowing a first flow of fluid in a sequence of flowing the fluid through a fluid supply of a printhead, a fluid inlet of a substrate attached to the printhead, a fluid outlet of the substrate, and to a fluid return of the printhead; and

simultaneous with flowing the first flow of fluid, flowing a second flow of fluid from the fluid supply to the fluid return, wherein the second flow of fluid does not pass through the substrate, the second flow of fluid being greater than the first flow of fluid,

wherein the first flow of fluid is in fluid communication with the second flow of fluid.

14. The method of claim 13, wherein the second flow of fluid causes a lower pressure at the fluid outlet of the substrate than at the fluid inlet of the substrate.

15. The method of claim 13, further comprising:

ejecting fluid droplets through nozzles in fluid communication with the fluid inlet.

16. The method of claim 13, further comprising:

simultaneous with flowing the first flow of fluid and the second flow of fluid, flowing a third flow of fluid from the fluid return to the fluid supply, wherein the third flow of fluid does not pass through the substrate or the printhead.

17. The method of claim 16, further comprising:

removing air or other contaminants from fluid in the third flow of fluid.

18. The method of claim 16, wherein the third flow of fluid flows from the fluid return, through a fluid return tank, through a fluid supply tank, and to the fluid supply.

19. The method of claim 18, further comprising:

controlling a difference in fluid height between the fluid return tank and the fluid supply tank.

20. The method of claim 19, wherein the difference in fluid height between the fluid return tank and the fluid supply tank is controlled by a fluid supply pump.

21. The method of claim 18, further comprising:

controlling a height of fluid in the fluid supply tank.

22. The method of claim 21, wherein the height of fluid in the fluid supply tank is controlled by a fluid supply pump.

23. The method of claim 13, further comprising:

monitoring a temperature of fluid in the first flow of fluid or the second flow of fluid.

24. The method of claim 23, further comprising:

controlling a temperature of fluid in the first flow of fluid or the second flow of fluid.