Nozzle arrangement with an electrically heated actuator

• US 6,938,992 B2
• Filed: 07/19/2004
• Issued: 09/06/2005
• 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): Meier, Stephen D.
• Assistant Examiner(s): Do, An H.
• Application Number:
  US10/893,380
• Publication Number:
  US 20040257406A1
• Time in Patent Office: 414 Days
• Field of Search: 347/20, 347/44, 347/47, 347/48, 347 54- 56, 347 61- 65
• 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 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• 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 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• 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 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 : Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 : Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14435 : Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14443 : Nozzle guard
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 : by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 : multi-dimensional coding
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G07F 7/08 : by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/086 : by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/12 : Card verification
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• 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
• CPC Class Codes: Y10T 29/49083 : Heater type
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49169 : Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49172 : by molding of insulating material
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

A micro-electromechanical fluid ejection mechanism includes a substrate that incorporates drive circuitry. A nozzle chamber structure is arranged on the substrate to define a nozzle chamber and a fluid ejection port in fluid communication with the nozzle chamber. An actuator is fast at one end with the substrate and extends into the nozzle chamber. The actuator includes an actuating member that is connected to the drive circuitry and is anchored at one end to the substrate. The actuating member is displaceable between a quiescent position and an active position to eject fluid from the ejection port. At least a portion of the actuating member is of a shape memory alloy which is configured so that, when the shape memory alloy makes a phase transformation, the actuating member is displaced between the quiescent and active positions. The actuating member is connected to the drive circuitry so that the shape memory alloy can be heated above its phase change temperature on receipt of an electrical signal from the drive circuitry.

Claims

1. A micro-electromechanical fluid ejection mechanism, the fluid ejection mechanism comprising

a substrate that incorporates drive circuitry;

a nozzle chamber structure arranged on the substrate to define a nozzle chamber and a fluid ejection port in fluid communication with the nozzle chamber; and

an actuator that is fast at one end with the substrate and that extends into the nozzle chamber, the actuator comprising

an actuating member that is connected to the drive circuitry and anchored at one end to the substrate, the actuating member being displaceable between a quiescent position and an active position to eject fluid from the ejection port, at least a portion of the actuating member being of an electrically conductive material which is configured so that, when the electrically conductive material is electrically heated, the actuating member is displaced between the quiescent and active positions, the actuating member being connected to the drive circuitry so that the electrically conductive material can be heated on receipt of an electrical signal from the drive circuitry.

2. A micro-electromechanical fluid ejection mechanism as claimed in claim 1, in which the actuating member incorporates a heating circuit of the shape memory alloy, the heating circuit being connected to the drive circuitry of the substrate.

3. A micro-electromechanical fluid ejection mechanism as claimed in claim 2, in which the actuating member is a laminated structure, with the heater circuit defining one layer of the actuating member.

4. A micro-electromechanical fluid ejection mechanism as claimed in claim 2, in which the actuating member includes a pre-stressing layer positioned on, and mechanically fast with, the heating circuit, the shape memory alloy having a generally planar form when in the austenitic phase and the pre-stressing layer serving to curl the actuating member away from the ejection port, when the shape memory alloy is in the martensitic phase, such that, when heated, the shape memory alloy drives the actuating member into a planar form, thereby ejecting a drop of ink from the ejection port.

5. A micro-electromechanical fluid ejection mechanism as claimed in claim 4, in which the shape memory alloy is a nickel titanium alloy.

6. A micro-electromechanical fluid ejection mechanism as claimed in claim 4, in which the pre-stressing layer is high stress silicon nitride.

7. A micro-electromechanical fluid ejection mechanism as claimed in claim 4, in which the heating circuit is interposed between the pre-stressing layer and a stress reference layer for the pre-stressing layer.

8. A micro-electromechanical fluid ejection mechanism as claimed in claim 1, in which the nozzle chamber structure is defined by the substrate as a result of an etching process carried out on the substrate, such that one of the layers of the substrate defines the ejection port on one side of the substrate and the actuator is positioned on an opposite side of the substrate.