Micro-electromechanical fluid ejection device with guided actuator movement

• US 7,125,102 B2
• Filed: 09/03/2004
• Issued: 10/24/2006
• 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): Do, An H.
• Application Number:
  US10/933,286
• Publication Number:
  US 20050024438A1
• Time in Patent Office: 781 Days
• Field of Search: 347/54, 347/56, 347/61, 347/65
• US Class Current: 347/54
• CPC Class Codes: B41J 2/04 generating single droplets or particles on demand
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• 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 2/17503 Ink cartridges
• 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 2202/21 : Line printing
• 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 7/1417 : 2D bar codes
• 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

Abstract

A micro-electromechanical fluid ejection device includes a substrate that defines a fluid inlet channel and incorporates a wafer and drive circuitry positioned on the wafer. Nozzle chamber walls extend from the substrate and bound the fluid inlet channel to define a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port. An elongate actuator is connected at one end to the drive circuitry. An opposite end of the actuator is displaceable towards and away from the substrate on receipt of an electrical signal from the drive circuitry. The actuator includes an interconnect portion that defines a transversely extending face and is received through a complementary opening defined in the walls and a fluid ejection member that is fast with said face. The interconnect portion and said opening are shaped so that movement of the fluid ejection member is controlled.

Claims

1. A micro-electromechanical fluid ejection device that comprises

a substrate that defines a fluid inlet channel and incorporates a wafer and drive circuitry positioned on the wafer;

nozzle chamber walls that extend from the substrate and bound the fluid inlet channel to define a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port;

an elongate actuator that is connected at one end to the drive circuitry, an opposite end of the actuator being displaceable towards and away from the substrate on receipt of an electrical signal from the drive circuitry, the actuator including an interconnect portion that defines a transversely extending face and is received through a complementary opening defined in the walls and a fluid ejection member that is fast with said face, the interconnect portion and said opening being shaped so that movement of the fluid ejection member is controlled; and

,

the interconnect portion including a block member that is fast with the actuator arm, and a pair of opposed, transversely extending members fast with the block member and defining the transversely extending face, the walls defining slotted openings to accommodate the block member and the transversely extending members so that fluid outflow through the openings is minimized.

2. A micro-electromechanical fluid ejection device as claimed in claim 1, in which the actuator includes an elongate actuator arm and a heater element capable of thermal expansion mounted on the actuator arm, the heater element defining an electrical circuit and being connected to the drive circuitry to receive an electrical current from the drive circuitry, the heater element being positioned so that resultant thermal expansion of the heater element results in the actuator being bent away from the substrate, thereby displacing the fluid ejection member towards the fluid ejection port to eject fluid from the fluid ejection port.

3. A micro-electromechanical fluid ejection device as claimed in claim 2, in which the heater element is positioned on one side of the actuator arm to be interposed between the actuator arm and the substrate, the actuator including a complementary element, having a similar Young'"'"'s modulus to that of the heater element, positioned on an opposite side of the actuator arm.

4. A micro-electromechanical fluid ejection device as claimed in claim 1, in which a rim bounds the slotted openings to minimize wicking of fluid along the walls.

5. A micro-electromechanical fluid ejection device as claimed in claim 1, in which a recess is defined in the substrate proximate the opening to inhibit wicking of fluid along the substrate.