Inkjet printhead construction

• US 6,742,873 B1
• Filed: 04/16/2001
• Issued: 06/01/2004
• Est. Priority Date: 04/16/2001
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Meier, Stephen D.
• Assistant Examiner(s): Do, An H.
• Application Number:
  US09/835,702
• Time in Patent Office: 1,142 Days
• Field of Search: 347/20, 347/40, 347/44, 347/47, 347/48, 347/54, 347/56, 347/59, 347/61, 347/63, 347/65
• US Class Current: 347/54
• 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 2/1601 : 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 2/1628 : 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 2/1646 : thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 : Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2002/14419 : Manifold
• 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

Abstract

An inkjet printhead constructed by micro-electromechanical systems (MEMS) processing techniques includes a plurality of ink ejection nozzles, each nozzle defining a nozzle chamber. The printhead has a plurality of external thermal bend actuators. Each actuator has a proximal end anchored to a substrate and a distal end connected to an ink ejection paddle within a respective chamber. The external thermal bend actuator further comprises a series of layers and includes a planar conductive heating circuit layer which includes a first portion adjacent said proximal end forming a planar conductive heating circuit for heating said thermal bend actuator, and a second portion extending to said ink ejection paddle. The second portion being electrically isolated from said first portion by means of a discontinuity in said planar conductive heating circuit layer. The discontinuity is located external to said nozzle chamber.

Claims

1. An inkjet printhead constructed by micro-electromechanical systems (MEMS) processing techniques comprises:

a plurality of ink ejection nozzles, each nozzle defining a nozzle chamber, a plurality of external thermal bend actuators, each actuator having a proximal end anchored to a substrate and a distal end connected to an ink ejection paddle within a respective chamber; and

wherein said external thermal bend actuator further comprises a series of layers and includes a planar conductive heating circuit layer which includes a first portion adjacent said proximal end forming a planar conductive heating circuit for heating said thermal bend actuator, and a second portion extending to said ink ejection paddle, said second portion being electrically isolated from said first portion by means of a discontinuity in said planar conductive heating circuit layer, said discontinuity being located external to said nozzle chamber.

2. An inkjet printhead as claimed in claim 1 wherein said discontinuity comprises a slot extending across the thermal bend actuator.

3. An inkjet printhead as claimed in claim 1 wherein said planar conductive heating circuit layer comprises substantially titanium nitride.

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