Micro-electromechanical fluid ejection device having a nozzle guard

• US 6,824,252 B2
• Filed: 12/08/2003
• Issued: 11/30/2004
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (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:
  US10/728,887
• Publication Number:
  US 20040080575A1
• Time in Patent Office: 358 Days
• Field of Search: 347/20, 347/22, 347/29, 347/40, 347/44, 347/47, 347/54, 347/56, 347/61, 347/48, 347/63, 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 2/14427 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 2/17513 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: B62B 1/125 : by means of telescoping elements
• CPC Class Codes: B62B 2205/22 : remotely controlled, e.g. from the handlebar
• CPC Class Codes: B62B 2205/30 : Detachable, retractable or collapsible load supporting means
• 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 CMOS layers positioned on the wafer. A nozzle chamber structure is positioned on the substrate to define a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port in fluid communication with the nozzle chamber. An actuator is connected to the CMOS layers and is operatively positioned with respect to the nozzle chamber. The actuator is displaceable on receipt of an electrical signal from the CMOS layers to act on fluid in the nozzle chamber to eject fluid from the fluid ejection port. A nozzle guard is mounted on the substrate to be spaced from and cover the nozzle chamber structure. The nozzle guard includes a body member that defines a passage that is aligned with the fluid ejection port so that fluid ejected from the fluid ejection port passes through the passage.

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 structure that is positioned on the substrate to define a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port in fluid communication with the nozzle chamber;

an actuator that is connected to the CMOS layers and operatively positioned with respect to the nozzle chamber, the actuator being displaceable on receipt of an electrical signal from the CMOS layers to act on fluid in the nozzle chamber to eject fluid from the fluid ejection port; and

a nozzle guard that is mounted on the substrate to be spaced from and cover the nozzle chamber structure, the nozzle guard including a body member that defines a passage that is aligned with the fluid ejection port so that fluid ejected from the fluid ejection port passes through the passage.

2. A micro-electromechanical fluid ejection device as claimed in claim 1, in which the nozzle guard includes support members that are fast with the substrate to support the body member above the nozzle chamber structure.

3. A micro-electromechanical fluid ejection device as claimed in claim 2, in which the support members define air inlet openings to permit air to be pumped into a region between the nozzle chamber structure and the body member and to exit through the passage.

4. A micro-electromechanical fluid ejection device as claimed in claim 1, in which the actuator is elongate and is connected at one end to the CMOS layers, an opposite end of the actuator being displaceable towards and away from the substrate on receipt of an electrical signal from the CMOS layers, the nozzle chamber structure including a nozzle that is connected to said opposite end of the actuator, the nozzle having a crown portion and a skirt portion that depends from the crown portion, the crown portion defining the fluid ejection port and the skirt portion being positioned so that the nozzle and the wall define the nozzle chamber, a volume of the nozzle chamber being reduced and subsequently enlarged as the nozzle is driven towards and away from the nozzle chamber by the actuator to eject fluid from the fluid ejection port.

5. A micro-electromechanical fluid ejection device as claimed in claim 4, in which an edge of the skirt portion is positioned adjacent an edge of the wall such that, when the nozzle chamber is filled with liquid, a meniscus is pinned by the edges of the skirt portion and the wall to define a fluidic seal that inhibits the egress of liquid from between the wall and the skirt as liquid is ejected from the fluid ejection port.

6. A micro-electromechanical fluid ejection device as claimed in claim 4, in which the crown portion includes a rim that defines the fluid ejection port, the rim providing an anchor point for a meniscus that is formed in the fluid ejection port when the chamber is filled with liquid.

7. A micro-electromechanical fluid ejection device which comprises

a substrate that defines a plurality of fluid inlet channels and incorporates a wafer and CMOS layers positioned on the wafer;

nozzle chamber structures that are positioned on the substrate to define nozzle chambers in fluid communication with respective fluid inlet channels and fluid ejection ports in fluid communication with respective nozzle chambers;

actuators that are connected to the CMOS layers and operatively positioned with respect to respective nozzle chambers, the actuators being displaceable on receipt of an electrical signal from the CMOS layers to act on fluid in the respective nozzle chambers to eject fluid from the fluid ejection ports; and

a nozzle guard that is mounted on the substrate to be spaced from and cover the nozzle chamber structures, the nozzle guard including a body member that defines passages that are aligned with respective fluid ejection ports so that fluid ejected from the fluid ejection ports passes through the passages.