Thermoelastic bend actuator ink jet printing mechanism

• US 6,293,653 B1
• Filed: 07/10/1998
• Issued: 09/25/2001
• 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): Barlow, John
• Assistant Examiner(s): Do, An H.
• Application Number:
  US09/113,128
• Time in Patent Office: 1,173 Days
• Field of Search: 347/20, 347/44, 347/54.56, 347/84.85, 347/47
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/16 Production of nozzles
• 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 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/14403 including a filter

Abstract

This patent describes an ink jet printer including an actuated paddle for the movement and ejection of liquid within a chamber. The paddle includes a hydrophobic surface close to a wall of the ejection chamber and amendable to the collection of gases. The paddle is actuated to move the hydrophobic surface away from the wall of the chamber. The paddle is thermally actuated by means of a first structure having a low coefficient of thermal expansion and a second structure comprising polytetrafluoroethylene having a substantially larger coefficient of thermal expansion. The paddle can be liquid cooled by the ink liquid and the position of elements is utilized to enhance operation through liquid cooling.

Claims

1. An actuated paddle situated for movement of liquid within a chamber comprising:

a first surface having a hydrophobic surface;

the paddle defining a cavity between said hydrophobic surface and a wall of the chamber so as to collect gases within said cavity and wherein the paddle is actuated to move the hydrophobic surface away from said wall of said chamber.

2. An actuated paddle as claimed in claim 1 wherein a degree of movement of said paddle is insufficient to substantially disperse said gases within said cavity.

3. An actuated paddle as claimed in claim 1 wherein said paddle is thermally actuated by means of a first structure having a low coefficient of thermal expansion and a second structure having a substantially higher coefficient of thermal expansion.

4. An actuated paddle as claimed in claim 3 wherein said second structure is located closer to said cavity than said first structure.

5. An actuated paddle as claimed in claim 3 wherein the paddle includes a further surface adjacent to said liquid and said first structure is located closest to said further surface.

6. An actuated paddle as claimed in claim 3 wherein said first structure is substantially liquid cooled by said liquid whereas said second structure is located substantially in said cavity.

7. An actuated paddle as claimed in claim 1 wherein said second structure is comprised substantially from polytetraflluoroethylene.

8. An actuated paddle as claimed in claim 1 wherein said first surface comprises substantially polytetrafluoroethylene.

9. An actuated paddle as claimed in claim 1 wherein the paddle is attached to said chamber wall.