Printhead having nozzle arrangements with radial actuators

• US 7,669,973 B2
• Filed: 11/24/2008
• Issued: 03/02/2010
• Est. Priority Date: 06/09/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Primary Examiner(s): Do; An H
• Application Number:
  US12/277,295
• Publication Number:
  US 20090122113A1
• Time in Patent Office: 463 Days
• Field of Search: 347/54, 347/56, 347/65
• US Class Current: 347/54
• CPC Class Codes: B41J 2/1433 Structure of nozzle plates
• 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 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14435 Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14475 characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate
• CPC Class Codes: Y10T 29/49401 Fluid pattern dispersing device making, e.g., ink jet

Abstract

A printhead for an inkjet printer has a wafer that defines a plurality of nozzle chambers and ink supply channels in fluid communication with the nozzle chambers to supply the nozzle chambers with ink. An ink ejection port is associated with each nozzle chamber. A series of actuators is associated with each nozzle chamber and is radially positioned with respect to the nozzle chamber. The actuators are operable so that, when activated, they are displaced into the nozzle chamber to generate an ink meniscus at the ink ejection port and, when deactivated, return to an original position resulting in the necking and breaking of the ink meniscus to eject an ink drop.

Claims

1. A printhead for an inkjet printer, the printhead comprising

a wafer that defines a plurality of nozzle chambers and ink supply channels in fluid communication with the nozzle chambers to supply the nozzle chambers with ink;

an ink ejection port associated with each nozzle chamber; and

a series of actuators associated with each nozzle chamber and radially positioned with respect to the nozzle chamber, the actuators being operable so that, when activated, they are displaced into the nozzle chamber to generate an ink meniscus at the ink ejection port and, when deactivated, return to an original position resulting in the necking and breaking of the ink meniscus to eject an ink drop.

2. A printhead as claimed in claim 1, in which the nozzle chambers and the ink supply channels are the result of an etching process carried out on the wafer.

3. A printhead as claimed in claim 1, in which each actuator comprises an electrically conductive heater element in a layer of a plastics material, the heater element being positioned in the plastics material to cause uneven heating and resulting uneven expansion so that the actuators bend into the nozzle chamber.

4. A printhead as claimed in claim 3, in which each heater element is serpentine to accommodate expansion of the actuators.

5. A printhead as claimed in claim 1, in which the wafer incorporates a CMOS layer that includes power and drive circuits for the actuators.

6. A printhead as claimed in claim 1, in which each actuator includes a polytetrafluoroethylene (PTFE) layer, and an internal serpentine copper core which is heated when carrying current to bend the actuators.

7. A printhead as claimed in claim 1, wherein bridges extend radially from a rim defining the ink ejection ports and between adjacent actuators.