Fluid flow restriction in an inkjet printhead

• US 6,299,290 B1
• Filed: 10/19/1999
• Issued: 10/09/2001
• Est. Priority Date: 11/09/1998
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): NGUYEN, THINH H
• Application Number:
  US09/425,417
• Time in Patent Office: 721 Days
• Field of Search: 347/54, 347/20, 347/44, 347/29, 347/90
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators

Abstract

An inkjet printhead, typically constructed by a MEMS process, includes a large number of nozzle chambers with ink ejection nozzle apertures and a paddle moveable in each chamber by an actuator to deliver ink through the nozzle. Each actuator extends through an aperture in a side wall of the nozzle chamber and is provided with a shield to inhibit leaking or wicking of ink from the chamber.

Claims

1. An inkjet printhead apparatus comprising:

a plurality of nozzle chambers each having a nozzle aperture defined in one wall thereof for the ejection of ink out of said chamber and a second aperture for the insertion of an actuator mechanism;

an ink supply channel interconnected with said nozzle chamber;

a paddle moveable by an actuator operable to eject ink from said nozzle chamber, said actuator including;

a first portion located externally of said nozzle chamber and

a second portion located internally of said nozzle chamber, supporting said paddle;

an interconnecting portion interconnecting said first portion and said second portion through said second aperture, said interconnecting portion further including a protruding shield formed adjacent said second aperture and positioned so as to restrict the flow of fluid through said second aperture.

2. An apparatus as claimed in claim 1 wherein said shield comprises a hydrophobic surface.

3. An apparatus as claimed in claim 1 wherein, in use, said interconnecting portion moves in an upwardly defined direction towards said liquid ejection aperture, and said shield is formed on an upper surface of said interconnecting portion.

4. An apparatus as claimed in claim 1 wherein said actuator includes a thermal expansion actuator.

5. An apparatus as claimed in claim 4 wherein said thermal expansion actuator is located in said first portion of said actuator.