Inkjet printhead having thermal bend actuator heating element electrically isolated from nozzle chamber ink

• US 7,111,924 B2
• Filed: 08/06/2002
• Issued: 09/26/2006
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): HSIEH, SHIH WEN
• Application Number:
  US10/487,821
• Publication Number:
  US 20040246305A1
• Time in Patent Office: 1,512 Days
• Field of Search: 347/54, 347/20, 347/44, 347/55, 347/62
• US Class Current: 347/54
• 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 2/0457 Power supply level being detected or varied
• 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 2/04596 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 2/1623 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 2/1637 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 2/1645 : 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 2002/14435 : Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14443 : Nozzle guard
• CPC Class Codes: B41J 2002/14491 : Electrical connection

Abstract

An ink jet printhead includes a number of nozzle devices formed on a substrate. Each nozzle device has a nozzle chamber, a nozzle opening through which ink from the nozzle chamber is ejected, a movable element in contact with ink in the nozzle chamber to cause the ejection of ink and thermal bend actuator. The thermal bend actuator has a proximal end anchored to the substrate and a distal end connected to the moveable element. The actuator includes a first portion adjacent the proximal end and having a conducting heating circuit layer for heating the actuator. A second end portion of the actuator extends to the movable element and is in contact with ink in the chamber. A dielectric slot electrically isolates the first and second portions so that electric energy in the heating circuit layer is not conducted by the actuator to the ink in the chamber.

Claims

1. An ink jet printhead comprising a plurality of nozzle devices formed on a substrate, each nozzle device comprising:

a nozzle chamber,

a nozzle opening through which ink from the nozzle chamber is ejected,

a movable element in contact with ink in the nozzle chamber to cause said ejection of ink,

a thermal bend actuator having a proximal end anchored to the substrate and a distal end connected to the movable element, the actuator including a first portion adjacent the proximal end external to the nozzle chamber and having a conductive heating circuit layer for heating the actuator, and a second portion extending to said movable element and in contact with said ink,

wherein said actuator and said movable element have substantially the same composition, the heating circuit layer defining a discontinuation between the first and second portions for electrically isolating said first and second portions so that electric energy in said heating circuit layer is not conducted by the actuator to said ink.

2. The ink jet printhead as claimed in claim 1 wherein said conductive heating circuit layer is substantially planar.

3. The ink jet printhead as claimed in claim 1 wherein said conducting heating layer comprises substantially titanium nitride.

4. The ink jet printhead as claimed in claim 1 wherein said conductive heating circuit includes at least one tapered portion adjacent said proximal end arranged to increase resistive heating adjacent said proximal end.

5. The ink jet printhead as claimed in claim 1 wherein said movable element is an ink ejection paddle located within the nozzle chamber and movable toward said nozzle opening to eject ink.

6. The ink jet printhead as claimed in claim 1 wherein said movable portion includes the nozzle opening and move towards the substrate to cause ejection of ink through the nozzle opening.

7. The printhead of claim 6 wherein each nozzle device comprises a crown portion defining the nozzle opening and a skirt portion depending from the crown portion, the skirt portion forming a first part of a peripheral wall of the nozzle chamber.

8. The printhead of claim 7 including an ink inlet aperture defined in a floor of the nozzle chamber and a bounding wall surrounding the aperture and defining a second part of the peripheral wall of the nozzle chamber.

9. The printhead of claim 8 in which the skirt portion is displaceable relative to the substrate and said bounding wall serves as an inhibiting means for inhibiting leakage of ink from the chamber.

10. An ink jet printhead comprising a plurality of nozzle devices formed on a substrate, each nozzle device comprising:

a nozzle chamber,

a nozzle opening through which ink from the nozzle chamber is ejected,

a movable element in contact with ink in the nozzle chamber to cause said ejection of ink,

a thermal bend actuator having a proximal end anchored to the substrate and a distal end connected to the movable element, the actuator including a first portion adjacent the proximal end external to the nozzle chamber and having a conductive heating circuit layer for heating the actuator, and a second portion extending to said movable element and in contact with said ink,

wherein said actuator and movable element have substantially the same composition with the conductive heating circuit layer defining a discontinuation between the first and second portions so that the first and second portions are electrically isolated from one another so that electric energy in said heating circuit layer is not conducted by the actuator to said ink.