Radiant plunger ink jet printer

• US 6,227,652 B1
• Filed: 07/10/1998
• Issued: 05/08/2001
• 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:
  US09/112,751
• Time in Patent Office: 1,033 Days
• Field of Search: 347/44, 347/53, 347/54, 347/93, 347/94, 347/20, 347/47
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14314 Structure of ink jet print heads with electrostatically actuated membrane
• CPC Class Codes: B41J 2/16 Production of nozzles
• 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 2/1639 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 2002/041 Electromagnetic transducer

Abstract

This patent describes an ink jet printer which uses an electro-mechanical activation process for the ejection of ink. A plunger is constructed from soft magnetic material and positioned between the nozzle chamber and an ink chamber. An electric coil is located adjacent to the plunger and electrically connected to a nozzle activation signal wherein upon activation of the activation signal, the plunger is caused by the coil to move thereby causing the ejection of ink. The electric coil is located within a cavity defined by the plunger. The plunger has a series of fluid release slots allowing for the expulsion of fluid under pressure in the cavity. A torsional spring is also provided for assisting in the return of the plunger.

Claims

1. An ink jet printing nozzle apparatus comprising:

(a) a nozzle chamber having an ink ejection port at one end;

(b) a plunger constructed from soft magnetic material and positioned between said nozzle chamber and an ink chamber, said plunger having a cavity formed therein, said ink chamber allowing for a supply of ink to said nozzle chamber, said plunger further having a series of fluid release apertures allowing for the expulsion of fluid under pressure in said cavity;

(c) an electric coil located substantially within said plunger cavity and electrically connected to a nozzle activation signal wherein upon activation of the activation signal, said plunger is caused by said coil to move from an ink loaded position to an ink ejection position thereby causing the ejection of ink from said ink ejection port, said fluid release apertures allowing for the expulsion of fluid under pressure in said cavity.

2. An ink jet printing nozzle apparatus as claimed in claim 1 further comprising an armature plate constructed from soft magnetic material and wherein said plunger is attracted to said armature plate on the activation of said coil.

3. An ink jet printing nozzle apparatus as claimed in claim 1 further comprising a resilient means for assisting in the return of said plunger from said ink ejection position to said ink loaded position after the ejection of ink from said ink ejection port.

4. An ink jet printing nozzle apparatus as claimed in claim 3 wherein said resilient means comprises a torsional spring.

5. An ink jet printing nozzle apparatus as claimed in claim 4 wherein said plunger has a substantially circular perimeter profile and said torsional spring is of an arcuate construction having a circumferential profile substantially the same as that of said plunger.

6. An ink jet printing nozzle apparatus as claimed in claim 1 wherein said plunger has a substantially circular perimeter and said plunger cavity is annular and further wherein said fluid release apertures are slots passing through said plunger.

7. An ink jet printing nozzle apparatus comprising:

(a) a nozzle having an ink ejection slot at one end;

(b) a plunger constructed from soft magnetic material positioned between said nozzle chamber and an ink chamber supplying ink to said nozzle chamber;

(c) an electric coil located adjacent to the plunger and electrically connected to a nozzle activation signal;

wherein said electric coil is located substantially within a cavity formed in said plunger, said plunger having along one surface a series of slots, said cavity being contracted as a result of movement of said plunger, said contraction resulting in an ink flow through said slots into said nozzle chamber and thereby assisting in the ejection of ink from said ink ejection port.

8. An ink jet printing nozzle apparatus as claimed in claim 7 wherein said slots are defined around an inner circumference of said coil and said slots have a substantially constant cross-sectional profile.

9. An ink jet printing nozzle apparatus as claimed in claim 7 wherein said slots are located in a radial manner on one surface of said plunger.