Pagewidth printhead having sealed inkjet actuators

• US 7,387,368 B2
• Filed: 12/08/2006
• Issued: 06/17/2008
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Do; An H
• Application Number:
  US11/635,533
• Publication Number:
  US 20070081031A1
• Time in Patent Office: 557 Days
• Field of Search: 347/54, 347/65, 347/61
• US Class Current: 347/61
• CPC Class Codes: B41J 2/04505 aiming at correcting alignment
• CPC Class Codes: B41J 2/04516 preventing formation of satellite drops
• CPC Class Codes: B41J 2/04518 reducing costs
• CPC Class Codes: B41J 2/0452 reducing demand in current or voltage
• CPC Class Codes: B41J 2/04528 aiming at warming up the head
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04553 detecting ambient temperature
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• CPC Class Codes: B41J 2/04565 detecting heater resistance
• CPC Class Codes: B41J 2/0457 Power supply level being detected or varied
• CPC Class Codes: B41J 2/04571 detecting viscosity
• CPC Class Codes: B41J 2/04585 controlling heads based on thermal bent actuators
• CPC Class Codes: B41J 2/04588 using a specific waveform
• CPC Class Codes: B41J 2/0459 Height of the driving signal being adjusted
• CPC Class Codes: B41J 2/04591 Width of the driving signal being adjusted
• CPC Class Codes: B41J 2/04593 Dot-size modulation by changing the size of the drop
• CPC Class Codes: B41J 2/04596 Non-ejecting pulses
• CPC Class Codes: B41J 2/04598 Pre-pulse
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/155 : for line printing
• CPC Class Codes: B41J 2/1623 : bonding and adhesion
• 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 2/1639 : sacrificial molding
• CPC Class Codes: B41J 2/1642 : thin film formation by CVD [chemical vapor deposition]
• 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 2002/14491 : Electrical connection
• CPC Class Codes: B41J 25/005 : for serial printing movements superimposed to character- or line-spacing movements
• CPC Class Codes: G06K 15/102 : using ink jet print heads
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

An inkjet printhead is provided having an elongate ink supply channel defined within a substrate and a plurality of inkjet nozzles arranged on the substrate to extend across a pagewidth. Each nozzle incorporates an actuator of a conductive heater, a paddle and an arm interconnecting the heater and paddle, and an ink ejection chamber having a first wall in which a first aperture for ink ejection is defined, a second wall in which a second aperture is defined through which the arm of the actuator passes so that the heater is outside the chamber and the paddle is inside the chamber, and a third wall in which a third aperture is defined through which ink from the ink supply channel is communicated. The arm of each actuator incorporates a protruding shield configured to restrict the flow of ink through the second aperture.

Claims

1. An inkjet printhead comprising:

an elongate ink supply channel defined in a substrate;

a plurality of inkjet nozzles arranged on the substrate to extend across a pagewidth, each nozzle incorporating;

an actuator comprising a conductive heater, a paddle and an arm interconnecting the heater and paddle; and

an ink ejection chamber having a first wall in which a first aperture for ink ejection is defined, a second wall in which a second aperture is defined through which the arm of the actuator passes so that the heater is outside the chamber and the paddle is inside the chamber, and a third wall in which a third aperture is defined through which ink from the ink supply channel is communicated,

wherein the arm of each actuator incorporates a protruding shield configured to restrict the flow of ink through the second aperture.

2. A printhead as claimed in claim 1, wherein the shield of each actuator arm incorporates a hydrophobic surface.

3. A printhead as claimed in claim 1, wherein the shield of each actuator arm is formed on an upper surface of the arm, and, in use, the arm of each actuator is moved in an upwardly defined direction towards the first aperture of the associated chamber.

4. A printhead as claimed in claim 1, wherein the actuator comprises thermally expansible material.

5. A printhead as claimed in claim 1, wherein the shield of each actuator arm is arranged adjacent the second aperture of the chamber.