Fluid ejection devices

Patent metadata

Field	Value
Publication number	US-2017190179-A1
Application number	US-201615395549-A
Country	US
Kind code	A1
Filing date	Dec 30, 2016
Priority date	Dec 31, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

A fluid ejector includes a nozzle layer, a body, an actuator and a membrane. The body includes a pumping chamber, a return channel, and a first passage fluidically connecting the pumping chamber to an entrance of the nozzle. A second passage fluidically connects the entrance of the nozzle to the return channel. The actuator is configured to cause fluid to flow out of the pumping chamber such that actuation of the actuator causes fluid to be ejected from the nozzle. The membrane is formed across and partially blocks at least one of the first passage, the second passage or the entrance of the nozzle. The membrane has at least one hole therethrough such that in operation of the fluid ejector fluid flows through the at least one hole in the membrane.

First claim

What is claimed is:

1 . A fluid ejector comprising:
a nozzle layer having an outer surface, and inner surface, and a nozzle extending between the inner surface and the outer surface, the nozzle having an entrance at the inner surface to receive fluid and an exit opening at an outer surface for ejection of fluid; a body to which the inner surface of the nozzle layer is secured, the body including a pumping chamber, a return channel, and a first passage fluidically connecting the pumping chamber to the entrance of the nozzle; a second passage fluidically connecting the entrance of the nozzle to the return channel; an actuator configured to cause fluid to flow out of the pumping chamber such that actuation of the actuator causes fluid to be ejected from the nozzle; and a membrane formed across and partially blocking at least one of the first passage, the second passage or the entrance of the nozzle, the membrane having at least one hole therethrough such that in operation of the fluid ejector fluid flows through the at least one hole in the membrane.

2 . The fluid ejector of claim 1 , wherein the membrane and hole are configured such that the first flow path has a first impedance when fluid is being ejected from the nozzle and a second impedance when fluid is not being ejected from the nozzle.

3 . The fluid ejector of claim 2 , wherein the first impedance is greater than the second impedance.

4 . The fluid ejector of claim 2 , wherein the membrane is configured such that second passage has a maximum impedance at or around a resonance frequency of the nozzle.

5 . The fluid ejector of claim 1 , wherein the membrane extends substantially parallel to the outer surface.

6 . The fluid ejector of claim 1 , wherein the membrane is formed across the second passage.

7 . The fluid ejector of claim 6 , wherein the second passage comprises a first portion between the entrance to the nozzle and the membrane and a second portion between the membrane and the return channel, wherein the first portion and the second portion are separated by the membrane and the holes through the membrane fluidically connect the first portion to the second portion.

8 . The fluid ejector of claim 7 , wherein the first portion is on a side of the membrane farther from the outer surface and the second portion is on a side of the membrane closer to the outer surface.

9 . The fluid ejector of claim 8 , wherein the first portion is in the body and the second portion is in the nozzle layer

10 . The fluid ejector of claim 1 , wherein the membrane has a plurality of holes therethrough.

11 . The fluid ejector of claim 10 , wherein the plurality of holes are spaced uniformly across the membrane.

12 . The fluid ejector of claim 1 , wherein the membrane is formed across the nozzle.

13 . The fluid ejector of claim 1 , comprising a membrane layer extending parallel to the outer surface and spanning the fluid ejector, and wherein the membrane includes a portion of the membrane layer.

14 . The fluid ejector of claim 13 , wherein the membrane layer is embedded in the body.

15 . The fluid ejector of claim 13 , wherein the membrane layer is between the body and the nozzle layer.

16 . The fluid ejector of claim 1 , wherein the hole is spaced away from walls of the first passage, the second passage or the nozzle, respectively, on all sides of the hole.

17 . The fluid ejector of claim 1 , wherein the membrane projects inwardly substantially perpendicular to walls of the first passage, the second passage or the nozzle, respectively.

18 . The fluid ejector of claim 1 , wherein the membrane is formed of a material that has a lower elastic modulus than an elastic modulus of a material forming walls of the first passage, the second passage or the nozzle, respectively.

19 . The fluid ejector of claim 1 , wherein the membrane is more flexible than walls of the first passage, the second passage or the nozzle, respectively.

20 . The fluid ejector of claim 1 , wherein the hole through the membrane is narrower than the exit opening of the nozzle.

21 . The fluid ejector of claim 1 , wherein the membrane is formed of an oxide.

22 . The fluid ejector of claim 21 , wherein the membrane has a thickness between about 0.5 μm and about 5 μm.

23 . The fluid ejector of claim 1 , wherein the membrane is formed of a polymer.

24 . The fluid ejector of claim 23 , wherein the membrane has a thickness between about 10 μm and about 30 μm.

25 . A fluid ejector comprising:
a substrate including a nozzle having an opening in an outer surface of the substrate, a flow path including a first portion from a pumping chamber to the nozzle and a second portion from the nozzle to a return channel, and an actuator configured to cause fluid to flow out of the pumping chamber such that actuation of the actuator causes fluid to be ejected from the nozzle; and a membrane formed across the second portion of the flow path, wherein the membrane has at least one hole therethrough and in operation fluid flow through the at least one hole in the membrane, and wherein the membrane is configured to provide an impedance to the flow path that depends on an oscillation frequency of fluid in the flow path.

26 . The fluid ejector of claim 25 , wherein the membrane is configured to provide a maximum impedance to the flow path at or around a resonance frequency of the nozzle.

27 . The fluid ejector of claim 25 , wherein the membrane is more flexible than walls of the flow path.

28 . The fluid ejector of claim 25 , wherein the membrane extends substantially parallel to the outer surface.

29 . A method of fluid ejection, comprising:
ejecting fluid from a nozzle of a fluid ejector; and refilling the nozzle with fluid from a flow path, wherein a membrane formed across the flow path provides the flow path with a first impedance when fluid is being ejected from the nozzle and a second impedance when fluid is not being ejected from the nozzle, and wherein the first impedance is greater than the second impedance.

30 . A method of fabricating a fluid ejector comprising:
forming a nozzle in a nozzle layer, the nozzle layer having a first surface in which the nozzle has an exit opening for ejection of fluid; forming a membrane on a second surface of the nozzle layer on a side of the nozzle layer farther from the first surface; forming at least one hole through the membrane; and attaching a side of the membrane farther from the nozzle layer to a wafer having a pumping chamber and a return channel such that the at least one hole in the membrane provides a constriction in a passage between the pumping chamber and the nozzle or a second passage between the nozzle and the return channel.

Assignees

• Fujifilm Dimatix Inc

Inventors

• Menzel Christoph
• Imai Darren

Classifications

• B41J2/14209 Primary

  of finger type, chamber walls consisting integrally of piezoelectric material · CPC title

• B41J2/01 Primary

  Ink jet · CPC title

• B41J2/14

  Structure thereof {only for on-demand ink jet heads} · CPC title

• B41J2/14233 Primary

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

• B41J2002/14459

  Matrix arrangement of the pressure chambers · CPC title