Fluid ejection device having an elongate micro-electromechanical actuator

• US 7,364,270 B2
• Filed: 12/12/2005
• Issued: 04/29/2008
• 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): Do; An H.
• Application Number:
  US11/298,635
• Publication Number:
  US 20060092229A1
• Time in Patent Office: 869 Days
• Field of Search: 347/54, 347/65
• 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 device includes a substrate that defines a fluid inlet channel and incorporates a wafer and CMOS layers positioned on the wafer. A nozzle chamber sidewall and roof are positioned on the substrate to define a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port in the roof, in fluid communication with the nozzle chamber. An elongate actuator is anchored at a proximal end portion to the substrate to receive electrical drive signals from the CMOS layers and extends through the sidewall. The elongate actuator is configured to be displaced on receipt of said drive signals. A fluid ejecting member is positioned in the nozzle chamber and is fast with a distal end portion of the actuator such that displacement of the actuator results in movement of the fluid ejecting member, thereby ejecting fluid from the fluid ejecting port. The distal end portion of the actuator has an enlarged face. The sidewall extends behind the face to define a slot through which the arm extends so that the face is positioned in the nozzle chamber and the roof defines a slot to accommodate reciprocal movement of the face.

Claims

1. A micro-electromechanical fluid ejection device that comprises

a substrate that defines a fluid inlet channel and incorporates a wafer and CMOS layers positioned on the wafer;

a nozzle chamber sidewall and roof positioned on the substrate to define a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port in the roof, in fluid communication with the nozzle chamber;

an elongate actuator anchored at a proximal end portion to the substrate to receive electrical drive signals from the CMOS layers and extending through the sidewall, the elongate actuator being configured to be displaced on receipt of said drive signals;

a fluid ejecting member positioned in the nozzle chamber and fast with a distal end portion of the actuator such that displacement of the actuator results in movement of the fluid ejecting member, thereby ejecting fluid from the fluid ejecting port, wherein

the distal end portion of the actuator has an enlarged face, the sidewall extending behind the face to define a slot through which the arm extends so that the face is positioned in the nozzle chamber and the roof defines a slot to accommodate reciprocal movement of the face.

2. A micro-electromechanical fluid ejection device as claimed in claim 1, in which an anchor post extends from the substrate and the proximal end portion of the actuator is fast with the actuator post so that the actuator extends into the nozzle chamber spaced from the substrate.

3. A micro-electromechanical fluid ejection device as claimed in claim 2, in which the actuator includes a heater portion and an actuator arm connected to the heater portion and extending into the nozzle chamber, the heater portion interposed between the anchor post and the actuator arm and connected to the CMOS layers such that heating and subsequent expansion of the heater portion serves to displace the actuator arm and thus the fluid ejecting member.

4. A micro-electromechanical fluid ejection device as claimed in claim 3, in which the heater portion includes a first layer that defines a heating circuit and a second layer spaced from the first layer such that the first layer is interposed between the substrate and the second layer, the first and second layers being substantially identical.

5. A micro-electromechanical fluid ejection device as claimed in claim 4, in which a cross-sectional area on the first and second layers decreases moving towards the anchor post so that a resistive heating effect is increased in the region of the anchor post to amplify movement of the actuator.

6. A micro-electromechanical fluid ejection device as claimed in claim 5, in which the layers each define a slot that tapers outwardly towards the anchor post.

7. A micro-electromechanical fluid ejection device as claimed in claim 6, in which the actuator arm includes a block-like portion that defines said face and provides structural rigidity to the actuator.