Linear stepper actuator ink jet printing mechanism

• US 6,247,794 B1
• Filed: 07/10/1998
• Issued: 06/19/2001
• 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:
  US09/113,061
• Time in Patent Office: 1,075 Days
• Field of Search: 347/20, 347/54, 347/53, 347/44, 347/47
• US Class Current: 347/54
• 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 2/1629 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 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• 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 2002/041 Electromagnetic transducer

Abstract

This patent describes an ink jet printer which uses a linear stepper actuator to eject ink from a nozzle chamber. The linear stepper actuator is interconnected to a plunger and actuates the plunger to eject ink. The plunger is sealed in the nozzle chamber and has a hydrophobic surface located alongside at least one wall of a nozzle chamber and the linear actuator is driven in three phases by a series of electromagnets which are duplicated for each driving phase and arranged in opposing pairs.

Claims

1. An ink jet print head comprising:

a nozzle chamber having an ink ejection port for ejection of ink from the nozzle chamber;

an ink supply reservoir for supplying ink to said nozzle chamber;

a plunger located within said nozzle chamber; and

a linear stepper actuator interconnected to said plunger and adapted to actuate said plunger so as to cause the ejection of ink from said ink ejection port.

2. An ink jet print head as claimed in claim 1 wherein said plunger has a hydrophobic surface located alongside at least one wall of said nozzle chamber.

3. An ink jet print head as claimed in claim 1 wherein said linear actuator is driven in three phases by a series of electromagnets.

4. An ink jet print head as claimed in claim 3 wherein said electromagnets are duplicated for each phase.

5. An ink jet print head as claimed in claim 4 wherein said each phase comprises four electromagnets.

6. An ink jet print head as claimed in one of claims 3-5 wherein said electromagnets are arranged in opposing pairs.

7. An ink jet print head as claimed in claim 1 wherein said nozzle chamber has an open wall along a back surface of said plunger.

8. An ink jet print head as claimed in claim 1 wherein said nozzle chamber comprises a series of posts adapted to form a filter to filter ink flowing into said nozzle chamber.

9. An ink jet print head as claimed in claim 1 wherein said linear stepper actuator includes a guide at an end opposite said nozzle chamber for guiding the linear actuator.