Magnetostrictive ink jet printing mechanism

• US 6,247,796 B1
• Filed: 07/10/1998
• Issued: 06/19/2001
• 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): Barlow, John
• Assistant Examiner(s): Do, An H.
• Application Number:
  US09/113,121
• Time in Patent Office: 1,075 Days
• Field of Search: 347/20, 347/44, 347/53, 347/54, 347/84, 347/85, 347/47, 216/27
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14314 Structure of ink jet print heads with electrostatically actuated membrane
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet 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 2/1643 thin film formation by plating
• 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 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

An ink jet printhead has a magnetostrictive actuator to eject ink from a nozzle chamber on demand. The actuator utilizes the phase transformation of a magnetostrictive material such as Terfenol-D in a magnetic field to cause the ejection of ink. The actuator includes a magnetostrictive paddle in a quiescent state which transfers to an ink ejection state upon the application of a magnetic field. The magnetic field is applied by passing a current through a conductive coil adjacent the magnetostrictive material.

Claims

1. A method of ejecting ink from a chamber comprising the steps of:

providing an actuator paddle formed of magnetostrictive material as a wall of said chamber, and

effecting a phase transformation of said magnetostrictive material in a magnetic field (or vice versa) to cause ejection of ink from said chamber.

2. A method as claimed in claim 1 wherein said actuator paddle transfers from a quiescent state to an ink ejection state upon application of said magnetic field thereby causing ink ejection from the chamber.

3. A method as claimed in claim 2 wherein said magnetic field is applied by passing a current through a conductive coil adjacent said magnetostrictive material.

4. A method as claimed in any preceding claim wherein said chamber is formed from a crystallographic etch of a silicon wafer and one surface of a said chamber substantially forms said actuator.

5. A method as claimed in claim 4 wherein said crystallographic etch provides side wall slots of non-etched layers of a processed silicon wafer so as to extend dimensionally the chamber as a result of the crystallographic etch process.

6. A method as claimed in claim 1 wherein said actuator forms one wall of said chamber opposite an ink ejection port from which ink is ejected.

7. A method as claimed in claim 6 wherein said ink ejection port is formed by back etching a silicon wafer to an epitaxial layer and etching a nozzle portal in said epitaxial layer.

8. An ink jet print head comprising:

a nozzle chamber having an ink ejection port in one wall of said nozzle chamber;

an ink supply source interconnected to said nozzle chamber;

a magnetostrictive actuator to eject ink from said nozzle chamber via said ink ejection port;

a magnetic field actuation means for producing a magnetic field around said magnetostrictive actuator so as to cause magnetostrictive operation of said actuator thereby causing said actuator to eject ink from said ink ejection port.

9. An ink jet print head as claimed in claim 8 wherein said magnetic field actuation means comprises a conductive coil surrounding said magnetostrictive actuator.

10. An ink jet print head as claimed in claim 9 wherein said nozzle chamber is formed on a silicon wafer using semiconductor processing techniques and said conductive coil is interconnected to a lower metal layer which provides control circuitry for said ink jet print head.

11. A method of ejecting ink from a chamber comprising the step of:

providing an actuator paddle formed of magnetostrictive material as a wall of said chamber, effecting a phase transformation of said magnetostrictive material in a magnetic field (or vice versa) to cause ejection of ink from said chamber wherein said ink ejection port is formed by back etching a silicon wafer to an epitaxial layer and etching a nozzle portal in said epitaxial layer.

12. A method as claimed in claim 11 wherein said crystallographic etch provided side wall slots of non-etched layers of a processed silicon wafer so as to extend dimensionally the chamber as a result of the crystallographic etch process.

13. An ink jet print head as claimed in claim 12 wherein said nozzle chamber is formed on a silicon wafer using semiconductor processing techniques and said conductive coil is interconnected to a lower metal layer which provides control circuitry for said ink jet print head.