Printhead nozzle arrangement with dual mode thermal actuator

• US 7,950,771 B2
• Filed: 06/28/2009
• Issued: 05/31/2011
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Nguyen; Lamson D
• Application Number:
  US12/493,215
• Publication Number:
  US 20090256890A1
• Time in Patent Office: 702 Days
• Field of Search: 347 9- 11, 347/13, 347/42, 347/49, 347 64- 65
• US Class Current: 347/42
• 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 2/04573 Timing; Delays
• 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 2/04591 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 2/1626 etching
• CPC Class Codes: B41J 2/1628 dry 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 2/175 : Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17513 : Inner structure
• CPC Class Codes: B41J 2/17553 : Outer structure
• CPC Class Codes: B41J 2002/14491 : Electrical connection
• CPC Class Codes: B41J 2202/21 : Line printing

Abstract

A pagewidth inkjet printhead assembly has a plurality of nozzle arrangements. Each nozzle arrangement comprises walls defining an ink chamber having an ink supply channel and an ink ejection port having an ink spreading prevention rim; a thermal actuator mechanism for ejecting ink from the chamber via the ejection port, the thermal actuator mechanism including an actuator arm having two layers which are formed from a conductive, resiliently flexible material, said layers surrounding a central material layer so that said two layers are in thermal balance with the arm in a quiescent state; and drive circuitry for supplying the thermal actuator mechanism with a drive current, the drive circuitry being operable in a first and second operative mode. Tn the first operative mode, the drive circuitry supplies current to the thermal actuator mechanism sufficient to cause the thermal actuator mechanism to bend to a degree whereby ink is expelled from the ink ejection port. In the second operative mode, the drive circuitry supplies current to the thermal actuator mechanism insufficient to cause ink the thermal actuator mechanism to bend to such degree whereby ink is expelled from the ink ejection port.

Claims

1. A pagewidth inkjet printhead assembly having a plurality of nozzle arrangements each comprising:

walls defining an ink chamber having an ink supply channel and an ink ejection port having an ink spreading prevention rim;

a thermal actuator mechanism for ejecting ink from the chamber via the ejection port, the thermal actuator mechanism including an actuator arm having two layers which are formed from a conductive, resiliently flexible material, said layers surrounding a central material layer so that said two layers are in thermal balance with the arm in a quiescent state; and

drive circuitry for supplying the thermal actuator mechanism with a drive current, the drive circuitry being operable in a first and second operative mode, wherein

in the first operative mode, the drive circuitry supplies current to the thermal actuator mechanism sufficient to cause the thermal actuator mechanism to bend to a degree whereby ink is expelled from the ink ejection port, and

in the second operative mode, the drive circuitry supplies current to the thermal actuator mechanism insufficient to cause ink the thermal actuator mechanism to bend to such degree whereby ink is expelled from the ink ejection port.

2. The pagewidth inkjet printhead assembly of claim 1, wherein the ink spreading prevention rim defines a pit for preventing ink from flowing across a surface of the ink jet printhead and affecting operation of said printhead.

3. The pagewidth inkjet printhead assembly of claim 1, wherein the thermal actuator mechanism includes an end paddle attached to an actuator arm which pivots at a post proximate the ink chamber.

4. The pagewidth inkjet printhead assembly of claim 1, wherein the conductive material includes titanium nitride.

5. The pagewidth inkjet printhead assembly of claim 1, wherein the actuator mechanism is actuated by electrical heating of one layer of the actuator arm to provide thermal bending to eject ink from the ink chamber.

6. The pagewidth inkjet printhead assembly of claim 1, which is manufactured according to micro-electromechanical system (MEMS) techniques.

7. The pagewidth inkjet printhead assembly of claim 6, wherein the nozzle rim and ink spread prevention rim are formed via a chemical mechanical planarization technique.