Dual chamber single actuator ink jet printing mechanism

• US 6,209,989 B1
• Filed: 07/10/1998
• Issued: 04/03/2001
• Est. Priority Date: 12/12/1997
• 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:
  US09/112,813
• Time in Patent Office: 998 Days
• Field of Search: 347/44, 347/54, 347/47, 347/20
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/16 Production of nozzles
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1632 machining
• 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 2/17596 Ink pumps, ink valves

Abstract

An apparatus for ejecting fluids from a nozzle chamber is disclosed including a nozzle chamber having at least two fluid ejection apertures defined in the walls of the chamber; a moveable paddle vane located between the fluid ejection apertures; an actuator mechanism attached to the moveable paddle vane and adapted to move the paddle vane in a first direction so as to cause the ejection of fluid drops out of a first fluid ejection aperture and to further move the paddle vane in a second alternative direction so as to cause the ejection of fluid drops out of a second fluid ejection aperture. The actuator can comprise a thermal actuator having at least two heater elements with a first of the elements being actuated to cause the paddle vane to move in a first direction and a second heater element being actuated to cause the paddle vane to move in a second direction. The heater elements preferably have a high bend efficiency. The paddle vane and the actuator can be joined at a fulcrum pivot point, the fulcrum pivot point having a thinned portion of the nozzle chamber wall. The actuator can include one end fixed to a substrate and a second end containing a bifurcated tongue having two leaf portions on each end of the bifurcated tongue the leaf portions interconnecting to a corresponding side of the paddle with the tongue such that, upon actuation of the actuator, one of the leaf portions pulls on the paddle end.

Claims

1. An apparatus for ejecting fluids from a nozzle chamber comprising:

a nozzle chamber having at least two fluid ejection apertures defined in the walls of said chamber;

a moveable paddle vane located between said fluid ejection apertures;

an actuator mechanism attached to said moveable paddle vane and adapted to move said paddle vane in a first direction so as to cause the ejection of fluid drops out of a first fluid ejection aperture and to further move said paddle vane in a second alternative direction so as to cause the ejection of fluid drops out of a second fluid ejection aperture.

2. An apparatus as claimed in claim 1 wherein said actuator comprises a thermal actuator having at least two heater elements with a first of said elements being actuated to cause said paddle vane to move in a first direction and a second heater element being actuated to cause said paddle vane to move in a second direction.

3. An apparatus as claimed in claim 2 wherein said heater elements have a high bend efficiency wherein said bend efficiency is defined as the youngs modulus times the coefficient of thermal expansion divided by the density and by the specific heat capacity.

4. An apparatus as claimed in claim 2 wherein said heater elements are arranged on opposite sides of a central arm, said central arm having a low thermal conductivity.

5. An apparatus as claimed in claim 4 wherein said central arm comprises substantially glass.

6. An apparatus as claimed in claim 2 wherein said paddle vane and said actuator are joined at a fulcrum pivot point, said fulcrum pivot point comprising a thinned portion of said nozzle chamber wall.

7. An apparatus as claimed in claim 1 wherein said actuator includes one end fixed to a substrate and a second end containing a bifurcated tongue having two leaf portions on each end of said bifurcated tongue said leaf portions interconnecting to a corresponding side of said paddle with said tongue such that, upon actuation of said actuator, one of said leaf portions pulls on said paddle end.

8. An apparatus as claimed in claim 1 further comprising:

a fluid supply channel connecting said nozzle chamber with a fluid supply for supplying fluid to said nozzle chamber said connection being in a wall of said chamber substantially adjacent the quiescent position of said paddle vane.

9. An apparatus as claimed in claim 8 wherein said connection comprises a slot defined in the wall of said chamber, said slot having similar dimensions to a cross-sectional profile of said paddle vane.

10. An apparatus as claimed in claim 1 wherein said fluid ejection apertures include a rim defined around an outer surface thereof.

11. A multiplicity of apparatuses as claimed in claim 1 wherein said fluid ejection apertures are grouped together spatially into spaced apart rows and fluid is ejected from the fluid ejection apertures of each of said rows in phases.

12. A multiplicity of apparatuses as claimed in claim 11 wherein said apparatuses are utilized for ink jet printing.

13. A multiplicity of apparatuses as claimed in claim 12 said nozzle chambers are further grouped into multiple ink colors and with each of said nozzles being supplied with a corresponding ink color.

14. A method of ejecting drops of fluid from a nozzle chamber having at least two nozzle apertures defined in the wall of said nozzle chambers utilizing a moveable paddle vane attached to an actuator mechanism, said method comprising the steps of:

actuating said actuator to cause said moveable paddle to move in a first direction so as to eject drops from a first of said nozzle apertures; and

actuating said actuator to cause said moveable paddle to move in a second direction so as to eject drops from a second of said nozzle apertures.

15. A method as claimed in claim 14 wherein an array of nozzle chambers are arranged in a pagewidth print head and the moveable paddles of each nozzle chamber are driven in phase.