Buckle grill oscillating pressure ink jet printing mechanism

• US 6,264,307 B1
• Filed: 07/10/1998
• Issued: 07/24/2001
• 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:
  US09/113,096
• Time in Patent Office: 1,110 Days
• Field of Search: 347/44, 347/54, 347/84, 347/85, 347/20, 347/47
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14314 Structure of ink jet print heads with electrostatically actuated membrane
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• 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 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

This patent describes an inkjet print nozzle having a shuttered ejection mechanism that is reliant upon the utilisation of a buckling device to activate the shutter. The shutter is located between the nozzle chamber and the ink supply source, the shutter being activated on demand to allow ink to pass through the shutter means and to thereby cause ink to be ejected from the nozzle chamber. The shutter can be activated by a buckle actuation mechanism attached to the shutter plate. The actuator can comprise a serpentine conductive material such as copper encased within an expansive material, such as polytetrafluoroethylene, having a high coefficient of thermal expansion such that, upon heating of the serpentine conductive material, the material concertinas so as to expand at a similar rate to the expansive material. The ink supply includes an ink supply channel interconnecting the shutter through the high density low pressure plasma etching of a hole in the ink jet wafer. The ink supply is driven with a substantially sinusoidal ink pressure so as to eject ink when the shutter is open. The shutter can be kept open during a subsequent high pressure time of the varying pressure sufficient to cause the nozzle chamber to be rapidly refilled so that the chamber is ready for ejection of ink upon the next opening of the shutter.

Claims

1. An ink jet print head comprising:

a nozzle chamber having an ink ejection port in one wall of said chamber;

an ink supply source interconnected to said nozzle chamber, said ink supply source including an ink supply under a varying pressure;

a shutter means located between said nozzle chamber and said ink supply source, said shutter being activated on demand to allow ink to pass through said shutter means and to thereby cause ink to be ejected from said nozzle chamber;

wherein said shutter means is actuated by means of a buckle actuation mechanism attached to a shutter plate.

2. An ink jet nozzle as claimed in claim 1 wherein said buckle actuation mechanism comprises:

a serpentine conductive material encased within an expansive material having a high coefficient of thermal expansion such that, upon heating of said serpentine conductive material, said material extends like a concertina so as to expand at a similar rate to said expansive material.

3. An ink jet nozzle as claimed in claim 2 wherein said expansive material comprises substantially polytetrafluoroethylene.

4. An ink jet nozzle as claimed in claim 2 wherein said serpentine conductive material comprises substantially copper.

5. An ink jet nozzle as claimed in claim 2 wherein said buckling is between stable end connector portions constructed from said conductive material.

6. An ink jet nozzle as claimed in claim 1 wherein said shutter means is closed when in a quiescent state.

7. An ink jet nozzle as claimed in claim 1 wherein said ink supply source includes an ink supply channel interconnecting said shutter means by means of a through hole etching of a silicon wafer.

8. An ink jet nozzle as claimed in claim 7 wherein said through hole etching is produced by high density low pressure plasma etching of said silicon wafer.

9. An ink jet nozzle as claimed in claim 1 wherein the ink within said ink supply source is driven with a substantially sinusoidal ink pressure.

10. A method of ejecting ink from a nozzle chamber in an ink jet print head which comprises:

a nozzle chamber having an ink ejection port in one wall of said chamber;

an ink supply source interconnected to said nozzle chamber, said ink supply source including an ink supply under a varying pressure;

shutter means located between said nozzle chamber and said ink supply source, said shutter being activated on demand to allow ink to pass through said shutter means and to thereby cause ink to be ejected from said nozzle chambers said shutter means being actuated by means of a buckle actuation mechanism attached to a shutter plate;

said method comprising the steps of;

(a) activating said shutter to an open position during a high pressure time of said varying pressure so as to cause the ejection of ink from said port;

(b) driving said pressure to a low pressure state so as to cause drop separation of ejected ink;

(c) keeping said shutter open during a subsequent high pressure time of said varying pressure sufficient to cause said nozzle chamber to be rapidly refilled;

(d) closing said shutter upon refill of said nozzle chamber such that said chamber is ready for the subsequent ejection of ink upon a subsequent opening of said shutter.