Ink jet with thin nozzle wall

• US 7,021,745 B2
• Filed: 03/02/2001
• Issued: 04/04/2006
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Gordon, Raquel Yvette
• Application Number:
  US09/798,741
• Publication Number:
  US 20010008407A1
• Time in Patent Office: 1,859 Days
• Field of Search: 347/54, 347/68, 347/69, 347/70, 347/71, 347/72, 347/50, 347/40, 347/20, 347/44, 347/47, 347/27, 399/261, 361/700, 298/901, 310328-330
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/14435 Moving nozzle made of thermal bend detached actuator

Abstract

An ink jet nozzle assembly for an ink jet printer includes a nozzle chamber having an ink inlet communicating with an ink reservoir and a nozzle through which ink from the chamber can be ejected onto a page. The chamber includes a fixed portion and a movable portion configured for relative movement in an ejection phase and alternate relative movement in a refill phase. The movable portion includes a number of thermal actuator petal devices arranged around a central stem. The petal devices undergo bending upon heating to effect periodically the relative movement. The inlet is positioned and dimensioned relative to the nozzle such that ink is ejected preferentially from the chamber through the nozzle in droplet form during the ejection phase, and ink is alternately drawn preferentially into the chamber from the reservoir through the inlet during the refill phase.

Claims

1. An ink jet nozzle assembly including:

a nozzle chamber having an inlet in fluid communication with an ink reservoir and a nozzle through which ink from the chamber can be ejected;

the chamber including a fixed portion and a movable portion configured for relative movement in an ejection phase and alternate relative movement in a refill phase;

the movable portion including a plurality of thermal actuator petal devices arranged around a central stem, said petal devices undergoing bending upon heating to effect periodically said relative movement; and

the inlet being positioned and dimensioned relative to the nozzle such that ink is ejected preferentially from the chamber through the nozzle in droplet form during the ejection phase, and ink is alternately drawn preferentially into the chamber from the reservoir through the inlet during the refill phase.

2. An assembly according to claim 1 wherein the movable portion includes the nozzle and the fixed portion is mounted on a substrate.

3. An assembly according to claim 1 wherein the fixed portion includes the nozzle mounted on a substrate and the movable portion includes the petal devices.

4. An assembly according to claim 1 wherein said petal devices bend generally toward said ink ejection port.

5. An assembly according to claim 4 wherein a surface of said petal devices which is to bend in a convex form is hydrophobic.

6. An assembly according to claim 4 wherein a surface of said petal device which is to bend in a concave form is hydrophilic.

7. An assembly according to claim 1 wherein said petal devices comprise a first material having a high coefficient of thermal expansion surrounding a second material which conducts resistively so as to provide for heating of said first material.

8. An assembly according to claim 7 wherein said second material is constructed so as to concertina upon expansion of said first material.

9. An assembly according to claim 7 wherein said first material comprises substantially polytetrafluoroethylene.

10. An assembly according to claim 7 wherein said second material comprises substantially copper.

11. An assembly according to claim 1 wherein, during operation, an air bubble forms under said petal devices.

12. An assembly according to claim 1 wherein a space between adjacent petal devices is reduced upon said bending upon heating.

13. An assembly according to claim 1 wherein the petal devices are attached to a substrate and heating of said petal devices is primarily near an attached end of each said petal device.

14. An assembly according to claim 1 wherein an outer surface of said ink chamber includes a plurality of etchant holes provided so as to allow rapid etching of a sacrificial layer during construction.

15. An assembly according to claim 1, manufactured using micro-electro-mechanical systems (MEMS) techniques.

16. An assembly according to claim 1, wherein the nozzle chamber has a wall having the nozzle formed therein, the wall being less than about 5 μ

m thick.

17. An assembly according to claim 16 wherein the wall is less than about 2 μ

m thick.

18. An assembly according to claim 16, manufactured using micro-electro-mechanical system (MEMS) techniques.