Thermal elastic rotary impeller ink jet printing mechanism

• US 6,362,843 B1
• Filed: 07/10/1998
• Issued: 03/26/2002
• 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): Barlow, John
• Assistant Examiner(s): Do, An H.
• Application Number:
  US09/112,794
• Time in Patent Office: 1,355 Days
• Field of Search: 347/44, 347/54, 347/38, 347/84, 347/85, 347/20, 416/19
• 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 ejection nozzle arrangement having an ink ejection port, the nozzle arrangement comprising:

a plurality of side walls which define a plurality of vane chambers;

a pivotally mounted paddle wheel; and

a plurality of radial paddle wheel vanes attached to the paddle wheel, the paddle wheel vanes being positioned with respect to the side walls and being configured so that rotary movement of the paddle wheel results in each wheel vane rotating with respect to the side walls so that ink within said paddle chambers can be pressurized, said pressurization causing ink to be ejected from the ink ejection port.

2. An ink ejection nozzle arrangement as claimed in claim 1 wherein the side walls include walls positioned radially with respect to the paddle wheel.

3. An ink ejection nozzle arrangement as claimed in claim 1 wherein a pivot point of the paddle wheel is located below the ink election port.

4. An ink ejection nozzle arrangement as claimed in claim 1 wherein the side walls include a plurality of circumferential walls located substantially on a circumference of the paddle wheel.

5. An ink ejection nozzle arrangement as claimed in claim 1 wherein the arrangement includes at least one thermal actuator to control rotation of the paddle wheel.

6. An ink ejection nozzle arrangement as claimed in claim 5 wherein the, or each, thermal actuator comprises an internal electrically resistive element and an external jacket around the resistive element, the jacket having a high coefficient of thermal expansion relative to the resistive element.

7. An ink ejection nozzle arrangement as claimed in claim 6 wherein the resistive element is of a substantially serpentine form.

8. An ink ejection nozzle arrangement as claimed in claim 5 wherein the external jacket comprises substantially polytetrafluoroethylene.

9. An ink ejection nozzle arrangement as claimed in claim 5 wherein the or each, thermal actuator undergoes circumferential expansion relative to the paddle wheel.

10. A method of ejecting ink from an ink jet nozzle arrangement having an ink ejection port the nozzle arrangement comprising a plurality of side walls which define a plurality of vane chambers, a pivotally mounted paddle wheel, a plurality of radial paddle wheel vanes attached to the paddle wheel, the paddle wheel vanes being positioned with respect to the side walls and being configured so that rotary movement of the paddle wheel results in each wheel vane rotating with respect to the side walls so that ink within said paddle chambers can be pressurized, said pressurization causing ink to be elected from the ink ejection port, the method comprising the step of rotating each wheel vane with respect to the side walls so that ink is ejected from the ink ejection port.