Ink jet with rotary actuator

• US 6,364,461 B2
• Filed: 05/14/2001
• Issued: 04/02/2002
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Gordon, Raquel Yvette
• Application Number:
  US09/854,825
• Publication Number:
  US 20020005877A1
• Time in Patent Office: 323 Days
• Field of Search: 347/54, 347/68, 347/69, 347/70, 347/71, 347/72, 347/50, 347/40, 347/20, 347/44, 347/47, 347/27, 347/63, 399/201, 399/700, 310/328-330, 298/901
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1632 machining
• 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 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling

Abstract

An ink jet printer utilizing a rotary impeller mechanism to eject ink drops is described. The nozzle chamber includes a number of radial paddle wheel vanes; and a number of fixed paddles. Upon rotation of the paddle wheel, ink within the paddle chambers is pressurized, causing ink to be ejected from the ink ejection port. The ink ejection port is located above a pivot point of the paddle wheel and includes a wall which is located substantially on the circumference of the paddle wheel. The rotation of the paddle wheel is controlled by a thermal actuator which comprises an internal electrically resistive element and an external jacket around the resistive element, the jacket having a high coefficient of thermal expansion and being constructed from polytetrafluoroethylene. The thermal actuator undergoes circumferential expansion relative to the paddle wheel.

Claims

1. An ink jet nozzle arrangement which comprises:

a nozzle chamber defining means which defines a chamber and which includes a wall defining an ink ejection port;

an ink ejecting device mounted in the chamber to be rotatable through at least a predetermined arc of rotation; and

an actuator operatively arranged relative to the device such that activation of the actuator causes rotation of the device through at least said predetermined arc with rotation of the device causing ejection of ink through the ink ejection port.

2. The arrangement of claim 1 in which at least one fixed surface-defining element is arranged in the chamber and at least one movable surface-defining element is carried by the device, rotary displacement of the device at least through said predetermined arc in an oscillatory manner causing, alternately, ejection of ink from the ink ejection port and refilling of the chamber with ink.

3. The arrangement of claim 2 which includes a plurality of radially extending fixed surface defining elements with the device carrying a corresponding number of movable surface-defining elements, at least certain of the fixed surface-defining elements having movable surface-defining elements associated with them.

4. The arrangement of claim 2 in which the actuator includes a carrier, the device being mounted on the carrier.

5. The arrangement of claim 4 in which the actuator includes a displacing means associated with the carrier for effecting oscillatory displacement of the carrier.

6. The arrangement of claim 5 in which the displacing means comprises a heater means which expands on being resistively heated.

7. The arrangement of claim 6 in which the heater means is at least partially embedded in a jacket, the jacket having a greater coefficient of thermal expansion than the heater means so that any expansion of the heater means is amplified by the jacket to increase an arc of movement of the carrier and, accordingly, the device.