Flow-through printhead with bypass manifold

Patent metadata

Field	Value
Publication number	US-11034149-B2
Application number	US-201916351115-A
Country	US
Kind code	B2
Filing date	Mar 12, 2019
Priority date	Mar 12, 2019
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

Printheads for a jetting apparatus. In one embodiment, a printhead comprises a plurality of flow-through jetting channels each configured to jet a print fluid out of a nozzle. The printhead further includes a supply manifold fluidly coupled to the flow-through jetting channels, a return manifold fluidly coupled to the flow-through jetting channels, and one or more bypass manifolds fluidly coupled between the supply manifold and the return manifold.

First claim

What is claimed is:

1. A printhead comprising:
a head member comprising a housing, and a plate stack attached to an interface surface of the housing that forms a plurality of flow-through jetting channels each configured to jet a print fluid, wherein the jetting channels each include a nozzle, a pressure chamber, and a diaphragm;
wherein the housing includes a supply manifold duct along the interface surface that forms a supply manifold fluidly coupled to the flow-through jetting channels;
wherein the housing further includes at least one return manifold duct along the interface surface that forms a return manifold fluidly coupled to the flow-through jetting channels; and
wherein the plate stack includes a diaphragm plate that forms diaphragms of the jetting channels that contact piezoelectric actuators of the printhead;
wherein the diaphragm plate includes at least one bypass manifold opening that coincides with the supply manifold duct and the at least one return manifold duct of the housing to form at least one bypass manifold disposed between the supply manifold and the return manifold to directly couple the supply manifold and the return manifold.

2. The printhead of claim 1 further comprising:
a first Input/Output (I/O) port fluidly coupled to the supply manifold; and
a second I/O port fluidly coupled to the return manifold.

3. The printhead of claim 1 wherein:
a fluid resistance of the at least one bypass manifold is greater than a fluid resistance of the flow-through jetting channels.

4. A jetting apparatus comprising:
the printhead of claim 1 ; and
a controller configured to control the printhead to jet the print fluid.

5. The printhead of claim 1 wherein the plate stack further comprises:
an upper restrictor plate;
an upper chamber plate and a lower chamber plate that form pressure chambers for the flow-through jetting channels;
a lower restrictor plate; and
a nozzle plate having nozzles for the flow-through jetting channels;
wherein the upper restrictor plate fluidly couples the pressure chambers to the supply manifold;
wherein the lower restrictor plate fluidly couples the pressure chambers to the return manifold.

6. A printhead comprising:
a housing having Input/Output (I/O) ports disposed at a top surface; and
a plate stack attached to an interface surface of the housing that forms a plurality of flow- through jetting channels, wherein the jetting channels each include a nozzle, a pressure chamber, and a diaphragm;
wherein the housing and the plate stack form:
a supply manifold that is fluidly coupled to a first one of the I/O ports and to the flow-through jetting channels;
a return manifold that is fluidly coupled to a second one of the I/O ports and to the flow-through jetting channels; and
at least one bypass manifold disposed between the supply manifold and the return manifold to directly couple the supply manifold and the return manifold;

wherein the plate stack includes a diaphragm plate that forms diaphragms for the flow- through jetting channels that contact piezoelectric actuators;
wherein the housing includes a supply manifold duct along the interface surface that forms the supply manifold, and one or more return manifold ducts along the interface surface that form the return manifold; and
wherein the diaphragm plate includes at least one bypass manifold opening that forms the at least one bypass manifold.

7. The printhead of claim 6 wherein the plate stack further comprises:
an upper restrictor plate;
an upper chamber plate and a lower chamber plate that form pressure chambers for the flow-through jetting channels;
a lower restrictor plate; and
a nozzle plate having nozzles for the flow-through jetting channels;
wherein the upper restrictor plate fluidly couples the pressure chambers to the supply manifold;
wherein the lower restrictor plate fluidly couples the pressure chambers to the return manifold.

8. The printhead of claim 7 wherein:
the nozzles of the nozzle plate are arranged in a single row.

9. The printhead of claim 7 wherein:
the nozzles of the nozzle plate are arranged in two rows.

10. The printhead of claim 7 wherein:
the nozzles of the nozzle plate are arranged in four rows.

11. The printhead of claim 6 wherein:
the return manifold ducts are disposed transversely on the interface surface toward short ends of the housing; and
the at least one bypass manifold opening is disposed toward short ends of the diaphragm plate, and extends longitudinally inward to coincide with the return manifold ducts and the supply manifold duct of the housing.

12. The printhead of claim 11 wherein:
the supply manifold duct comprises a loop around an access hole in the housing; and
the at least one bypass manifold opening coincides with a section of the supply manifold duct that is disposed transversely.

13. The printhead of claim 12 wherein:
the diaphragm plate further includes:
supply manifold openings disposed longitudinally to coincide with longitudinal sections of the supply manifold duct; and
return manifold openings disposed toward corners of the diaphragm plate to coincide with the return manifold ducts.

14. The printhead of claim 6 wherein:
a fluid resistance of the at least one bypass manifold is greater than a fluid resistance of the flow-through jetting channels.

15. A jetting apparatus comprising:
at least one printhead configured to jet droplets onto a medium; and
a controller configured to control the at least one printhead;
wherein the at least one printhead includes piezoelectric actuators, a housing, and a plate stack attached to an interface surface of the housing that forms a plurality of flow-through jetting channels each comprising a nozzle, a pressure chamber, and a diaphragm;
wherein the housing includes a supply manifold duct along the interface surface that forms a supply manifold configured to supply a print fluid to the flow-through jetting channels;
wherein the housing further includes return manifold ducts along the interface surface that forms a return manifold configured to receive the print fluid from the flow-through jetting channels;
wherein the plate stack includes a diaphragm plate that forms diaphragms of the jetting channels that contact the piezoelectric actuators;
wherein the diaphragm plate includes at least one bypass manifold opening that coincides with the supply manifold duct and the return manifold ducts of the housing to form at least one bypass manifold that fluidly couples the supply manifold and the return manifold directly.

16. The jetting apparatus of claim 15 wherein:
a fluid resistance of the at least one bypass manifold is greater than a fluid resistance of the flow-through jetting channels.

17. The jetting apparatus of claim 15 wherein the plate stack comprises:
the diaphragm plate;
an upper restrictor plate;
an upper chamber plate and a lower chamber plate that form the pressure chamber for each of the flow-through jetting channels;
a lower restrictor plate; and
a nozzle plate having the nozzle for each of the flow-through jetting channels;
wherein the upper restrictor plate fluidly couples the pressure chambers to the supply manifold;
wherein the lower restrictor plate fluidly couples the pressure chambers to the return manifold.

18. The jetting apparatus of claim 15 wherein:
the return manifold ducts are disposed transversely on the interface surface toward short ends of the housing; and
the at least one bypass manifold opening is disposed toward short ends of the di

Assignees

• Nishimura Hiroshi
• Ricoh Co Ltd

Inventors

• Nishimura Hiroshi

Classifications

• B41J2002/14419

  Manifold · CPC title

• B41J2002/14306

  Flow passage between manifold and chamber · CPC title

• B41J2202/12

  with ink circulating through the whole print head · CPC title

• B41J2/14233 Primary

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

• B41J2/14201

  Structure of print heads with piezoelectric elements · CPC title