Droplet deposition apparatus and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9566786-B2
Application number	US-201415038661-A
Country	US
Kind code	B2
Filing date	Nov 25, 2014
Priority date	Nov 26, 2013
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A droplet deposition apparatus, such as an inkjet printhead, that includes an integrally-formed manifold component and one or more actuator components; these actuator components provide an first array of fluid chambers, each of which has a piezoelectric actuator element and a nozzle, with this piezoelectric actuator element being able to cause the release in a deposition direction of fluid droplets through the nozzle in response to electrical signals; the first array of fluid chambers extends in an array direction from a first longitudinal end to a second, opposite longitudinal end, this array direction being perpendicular to the deposition direction; in addition, the manifold component is elongate in the array direction and includes a first and second manifold chambers, with these manifold chambers extending side-by-side in the array direction and the first manifold chamber being fluidically connected to the second manifold chamber via each of the fluid chambers in the first array; the cross-sectional area of at least one of these manifold chambers is tapered with distance in the array direction, for example to improve purging of the chambers during start-up; the cross-sectional shape of the integrally-formed manifold component perpendicular to the array direction varies with distance in the array direction such that the centroid of the cross-section remains a substantially constant distance, in said deposition direction, from said array of fluid chambers over the length of the first array of fluid chambers, with the integrally-formed manifold component thus being essentially self-stiffening.

First claim

The invention claimed is:

1. Droplet deposition apparatus comprising an integrally-formed manifold component and one or more actuator components;
wherein said one or more actuator components provide a first array of fluid chambers, each having a piezoelectric actuator element and a nozzle, said piezoelectric actuator element being operable to cause the release in a deposition direction of fluid droplets through said nozzle in response to electrical signals, said first array of fluid chambers extending in an array direction from a first longitudinal end to a second, opposite longitudinal end, said array direction being generally perpendicular to said deposition direction;
wherein the manifold component is elongate in said array direction and comprises a first manifold chamber and a second manifold chamber, said first and second manifold chambers extending side-by-side in said array direction and said first manifold chamber being fluidically connected to said second manifold chamber via each of said fluid chambers in said first array;
wherein the cross-sectional area of at least one of said first manifold chamber and said second manifold chamber tapers with distance in the array direction;
and wherein the cross-sectional shape of said manifold component perpendicular to said array direction varies with distance in the array direction such that the centroid of the cross-section remains a substantially constant distance, in said deposition direction, from said array of fluid chambers over the length of the first array of fluid chambers.

2. Apparatus according to claim 1 , wherein the distance, in said deposition direction, between the centroid of said cross-section of the manifold component and the first array of fluid chambers varies by no more than 10% over the length of the first array of fluid chambers.

3. Apparatus according to claim 1 , wherein the cross-sectional shape of said manifold component perpendicular to said array direction varies with distance in the array direction such that the centroid of the cross-section remains at substantially the same location over the length of the first array of fluid chambers with respect to a manifold width direction, which is normal to said deposition direction and said deposition direction.

4. Apparatus according to claim 1 , wherein said one or more actuator components further provide a second array of fluid chambers, each having a piezoelectric actuator element and a nozzle, said piezoelectric actuator element being operable to cause the release in said deposition direction of fluid droplets through said nozzle in response to electrical signals, said second array of fluid chambers extending side-by-side with said first array of fluid chambers in said array direction from a first longitudinal end to a second, opposite longitudinal end; and
further comprising a third manifold chamber that extends side-by-side in said array direction with said first manifold chamber, and wherein said first manifold chamber is fluidically connected to said third manifold chamber via each of said fluid chambers in said second array.

5. Apparatus according to claim 1 , wherein said manifold component is substantially symmetric about a plane defined by said array and deposition directions.

6. Apparatus according to claim 1 , wherein, with respect to said array direction, said first and second manifold chambers each extend beyond both said first and second longitudinal ends of said first array of fluid chambers.

7. Apparatus according to claim 4 , wherein, with respect to said array direction, all of said manifold chambers extend beyond the respective first and second longitudinal ends of both said first and second arrays of fluid chambers.

8. Apparatus according to claim 7 , wherein, with respect to said array direction, the centers of said manifold chambers and said array(s) of fluid chambers are generally aligned.

9. Apparatus according claim 4 , further comprising a fluid junction where a first conduit branches into second and third conduits, said second and third conduits being connected respectively to said second and third manifold chambers, wherein said conduits are provided substantially by said manifold component.

10. Apparatus according to claim 9 , wherein, when viewed in said deposition direction, at least a portion of said fluid junction overlaps with said first manifold chamber and wherein said conduits and said junction are generally located, with respect to said array direction, beyond a longitudinal end of said first and second arrays of fluid chambers.

11. Apparatus according to claim 1 , wherein, so as to provide the taper of said at least one of said first manifold chamber and said second manifold chamber, the height in said deposition direction is varied with distance in the array direction.

12. Apparatus according to claim 1 , further comprising:
a heatsink, the heatsink being shaped so as to engage around the opposing side of the manifold component to said actuator components, wherein said heatsink engages loosely with said manifold component such that it substantially does not transfer mechanical stress to the manifold component during use; and
drive circuitry for supplying drive signals to said piezoelectric actuator elements, said heatsink also being in thermal contact with said drive circuitry.

13. Apparatus according to claim 12 , wherein said heatsink is in thermal contact with one or more side surfaces presented by said manifold component, said side surfaces extending in said array direction and said deposition direction wherein one or more of said side surfaces is located adjacent a corresponding one of said manifold chambers.

14. Apparatus according to claim 1 , wherein the cross-sectional shape, taken perpendicular to said array direction, of at least one said manifold chambers is generally elongate in said deposition direction.

15. Apparatus according to claim 1 , wherein said manifold component includes one or more ribs, said ribs being located above said manifold chambers on the opposite side of said manifold component to said actuator components, wherein respective ribs are provided for each of said manifold chambers; and
wherein the height of said ribs in the deposition direction tapers with distance in the array direction, this taper counteracting the taper of the cross-sectional area of the manifold chambers such that the centroid of the cross-section remains a substantially constant distance, in said deposition direction, from said array of fluid chambers over the length of the first array of fluid chambers.

16. Apparatus according to claim 15 , further comprising:
a heatsink, the heatsink being shaped so as to engage around the opposing side of the manifold component to said actuator components, wherein said heatsink engages loosely with said manifold component such that it substantially does not transfer mechanical stress to the manifold component during use; and
drive circuitry for supplying drive signals to said piezoelectric actuator elements, said heatsink being in thermal contact with with a side surface of at least one of said ribs that extends in said array direction and said deposition direction.

17. Apparatus according claim 1 , wherein said manifold component is formed substantially of a polymeric material.

18. Apparatus according claim 1 , wherein said manifold is formed by injection molding.

Assignees

• Xaar Technology Ltd

Inventors

• Brook Colin
• Ristea Alin
• Walsh Michael
• Gosling Chris

Classifications

• B41J2202/12

  with ink circulating through the whole print head · CPC title

• B29K2101/10

  Thermosetting resins · CPC title

• B41J2/161

  of film type, deformed by bending and disposed on a diaphragm · CPC title

• B41J2/155

  for line printing · CPC title

• B29K2023/06

  PE, i.e. polyethylene · CPC title