Micro-electromechanical liquid ejection device

• US 7,008,046 B2
• Filed: 11/17/2003
• Issued: 03/07/2006
• 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): Gordon, Raquel Yvette
• Application Number:
  US10/713,093
• Publication Number:
  US 20040095436A1
• Time in Patent Office: 841 Days
• Field of Search: 347/55, 347/151, 347/120, 347/141, 347/154, 347/103, 347/123, 347/111, 347/159, 347/127, 347/128, 347/131, 347/125, 347/158, 399/261, 361/700, 310328-330, 298/901
• US Class Current: 347/55
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1601 Production of bubble jet print heads B41J2/1606, B41J2/162 take precedence
• 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 2002/14475 : characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B41J 3/445 : Printers integrated in other types of apparatus, e.g. printers integrated in cameras
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 1/1626 : with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• 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: 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 liquid ejection device includes a substrate that incorporates drive circuitry. Nozzle chamber walls are positioned on the substrate to define a nozzle chamber. The nozzle chamber walls include a roof wall that defines an ejection port in fluid communication with the nozzle chamber. The substrate defines an inlet passage through the substrate and into the nozzle chamber. An elongate drive member is fast with the substrate at a fixed end and incorporates an electrical circuit that is in electrical contact with the drive circuitry to receive an electrical signal from the drive circuitry. The drive member is configured so that a free end is displaced relative to the substrate on receipt of the electrical signal. A motion-transmitting member is fast with the free end of the drive member so that the motion-transmitting member is displaced together with the free end. An elongate liquid displacement member is fast at one end with the motion-transmitting member and extends into the nozzle chamber to be displaced together with the motion-transmitting member to eject liquid from the ejection port.

Claims

1. A micro-electromechanical liquid ejection device that comprises

a substrate that incorporates drive circuitry;

nozzle chamber walls that are positioned on the substrate to define a nozzle chamber, the nozzle chamber walls including a roof wall that defines an ejection port in fluid communication with the nozzle chamber, the substrate defining an inlet passage through the substrate and into the nozzle chamber;

an elongate drive member, the drive member being fast with the substrate at a fixed end and incorporating an electrical circuit that is in electrical contact with the drive circuitry to receive an electrical signal from the drive circuitry, the drive member being configured so that a free end of the drive member is displaced relative to the substrate on receipt of the electrical signal;

a motion-transmitting member that is fast with the free end of the drive member so that the motion-transmitting member is displaced together with the free end; and

an elongate liquid displacement member that is fast at one end with the motion-transmitting member and extends into the nozzle chamber to be displaced together with the motion-transmitting member to eject liquid from the ejection port.

2. A liquid ejection device as claimed in claim 1, in which the motion-transmitting member defines a first class lever and has an effort formation that is fast with the free end of the drive member, a load formation that is fast with the liquid displacement member and a fulcrum formation that is fast with the substrate, the effort and load formations being pivotal with respect to the fulcrum formation.

3. A liquid ejection device as claimed in claim 2, in which the drive member, the working member and the fulcrum formation are of the same material, while the effort formation and the load formation are of a different material to that of the drive member and the working member.

4. A liquid ejection device as claimed in claim 3, in which the fulcrum formation is configured to facilitate resilient deformation of the fulcrum formation to accommodate movement of the effort formation and the load formation.

5. A liquid ejection device as claimed in claim 2, in which the fulcrum formation and the load formation define one of the nozzle chamber walls, the roof wall and the load formation defining a gap to permit relative movement of the load formation and the roof wall, the load formation and the roof wall further defining meniscus anchor points to permit liquid in the nozzle chamber to form a meniscus that spans the gap so that the meniscus can define a fluidic seal to inhibit the egress of ink from the nozzle chamber.

6. A liquid ejection device as claimed in claim 1, in which the drive member is a thermal bend actuator of the type that uses differential thermal expansion to achieve displacement.

7. A liquid ejection device as claimed in claim 6, in which the thermal bend actuator is of a conductive material that is capable of thermal expansion and has an active portion and a passive portion, the active portion defining the electrical circuit, in the form of a heating circuit, so that the active portion is heated and expands relative to the passive portion on receipt of the electrical signal to generate displacement of the actuator in one direction and termination of the signal results in contraction of the active portion to generate displacement of the actuator in an opposite direction.

8. A liquid ejection device as claimed in claim 7, in which the conductive material of the actuator is resiliently flexible to facilitate said displacement of the actuator in the opposite direction.

9. A printhead chip that comprises a plurality of liquid ejection devices as claimed in claim 1.