Pagewidth inkjet printhead assembly with actuator drive circuitry

• US 7,134,740 B2
• Filed: 10/13/2004
• Issued: 11/14/2006
• 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): Do, An H.
• Application Number:
  US10/962,415
• Publication Number:
  US 20050052497A1
• Time in Patent Office: 762 Days
• Field of Search: 347/54, 347/56, 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 2/1623 : 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

A pagewidth inkjet printhead assembly includes an ink supply assembly that spans a print medium, in use. A number of printhead segments are mounted on the ink distribution assembly to span the print medium, in use. Each segment includes a substrate that defines a number of ink inlet channels. Each ink inlet channel is in fluid communication with a corresponding ink supply assembly. Micro-electromechanical nozzle arrangements each include nozzle chamber walls that define a nozzle chamber and an ink ejection port, in fluid communication with the nozzle chamber. An elongate actuator is anchored, at one end, to the substrate and is displaceable with respect to the substrate on receipt of an electrical current. An ink ejection member is fast with an opposite end of the actuator and is positioned in the nozzle chamber such that the ink ejection member acts to eject ink from the nozzle chamber when the actuator is displaced. Drive circuitry for each actuator is interposed between the actuator and the substrate to supply the actuator with said electrical current and to control operation of the actuator.

Claims

1. A pagewidth inkjet printhead assembly which comprises

an ink supply assembly that spans a print medium, in use;

printhead segments that are mounted on the ink distribution assembly to span the print medium, in use, each segment comprising

a substrate that defines a number of ink inlet channels, each inlet channel being in fluid communication with a corresponding ink supply assembly; and

a plurality of micro-electromechanical nozzle arrangements positioned on the substrate, each nozzle arrangement comprising

nozzle chamber walls that define a nozzle chamber in fluid communication with an ink inlet channel, and an ink ejection port, in fluid communication with the nozzle chamber;

an elongate actuator tat is anchored, at one end, to the substrate so as to define a suspended arm within the nozzle chamber, a free end of the elongate actuator being displaceable with respect to the substrate on receipt of an electrical current; and

an ink ejection member fast with the free end of the actuator and positioned in the nozzle chamber such that the ink ejection member acts to eject ink from the nozzle chamber when the actuator is displaced,

wherein drive circuitry for each actuator is interposed between the actuator and the substrate to supply the actuator with said electrical current and to control operation of the actuator.

2. A pagewidth inkjet printhead assembly as claimed in claim 1, in which each actuator includes an actuator arm of a laminated structure, with one layer being of metal and defining a heating circuit so that the metal layer heats and expands when a current is set up in the heating circuit and cools and contracts when the current is cut off, the metal layer being positioned such that expansion and contraction of the heater layer generates differential expansion and contraction in the arm, resulting in displacement of the arm with respect to the substrate.

3. A pagewidth inkjet printhead assembly as claimed in claim 1, in which the drive circuitry for each actuator includes drive transistor circuitry to supply said electrical current to the actuator and transfer register circuitry to enable operation of the actuator with the electrical current.

4. A pagewidth inkjet printhead assembly as claimed in claim 3, in which the transfer register circuitry includes enable gate circuitry and shift register circuitry, the enable gate circuitry being interposed between the shift register circuitry and the drive transistor circuitry.

5. A pagewidth inkjet printhead assembly as claimed in claim 3, in which the drive transistor circuitry is at least partially defined by traces that extend transversely with respect to a longitudinal axis of the actuator arm.

6. A pagewidth printhead assembly as claimed in claim 4, in which the metal layer defines a series of transversely extending corrugations that correspond generally with said transversely extending traces.

7. A pagewidth inkjet printhead assembly as claimed in claim 1, in which the ink supply assembly includes an ink distribution manifold, the printhead segments being connected to the manifold, and at least one ink storage chamber mounted on the manifold to supply the manifold with ink.