Linear spring electromagnetic grill ink jet printing mechanism

• US 6,264,306 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:
  US09/112,772
• Time in Patent Office: 1,110 Days
• Field of Search: 347/54, 347/44, 347/20, 347/38, 347/75, 347/84, 347/85, 347/68-72
• 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 2/1628 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: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 a shuttered ink jet nozzle having a shutter located between the ink reservoir and an ink chamber so as to allow or restrict the flow of ink between the ink chamber and ink reservoir to thereby cause the ejection of ink from the. chamber, the shutter being actuated on demand. The shutter can an electromagnetic coil mechanism attracting a magnetic plate. The coil is anchored to a wafer and the magnetic plate is connected to a shutter plate and adapted to open and close over a series of shutter holes allowing fluid communication between the ink reservoir and the ink chamber. The actuator can include linear springs so as to amplify the travel of a shutter plate covering shutter holes upon activation of the actuator. The ink reservoir includes ink under an oscillating ink pressure which is ejected from the nozzle chamber when the shutters are in an open position. An array of ink jet nozzles can be constructed and grouped into phase groups and each phase group is activated in turn so as to reduce pressure requirements in an ink jet reservoir. The shutters can be used to cause ink to be ejected from the nozzle chamber, followed by leaving the shutter open during a subsequent high pressure period to allow rapid refill, followed by closing the shutter at the end of a high pressure cycle so as to restrict back flow of ink from the nozzle chamber to the ink reservoir.

Claims

1. An ink jet printhead comprising:

(a) an ink chamber having an ink ejection nozzle for the ejection of ink from said ink chamber;

(b) an ink reservoir for the supply of ink to said ink chamber under pressure;

(c) at least one linear spring; and

(d) a shutter device located between said ink reservoir and said ink chamber and interacting with said at least one linear spring so as to allow or restrict flowing of ink between the ink chamber and ink reservoir to thereby cause ink to be ejected from said chamber, said shutter device being actuated on demand and having its movement amplified by said linear spring.

2. An ink jet printhead as claimed in claim 1 wherein said shutter device comprises an electromagnetic coil mechanism attracting a magnetic bar.

3. A shuttered ink jet nozzle as claimed in claim 2 wherein said coil is anchored to a wafer and said magnetic bar is connected to shutter plate adapted to open and close over a series of shutter holes allowing fluid communication between said ink reservoir and said ink chamber.

4. An ink jet printhead as claimed in claim 2 wherein said shutter device includes a shutter plate that travels over shutter holes upon activation of said shutter device.

5. An ink jet printhead as claimed in claim 4 wherein said linear spring is anchored on one side of said ink chamber and said electromagnetic coil is anchored to an opposite side of said ink chamber, the a shutter plate operable between said linear spring anchor and said electromagnetic anchor.

6. A shuttered ink jet nozzle as claimed in any of claims 1 to 5 wherein said ink reservoir includes ink under an oscillating ink pressure.

7. An ink jet printhead as claimed in claim 6 wherein ink in said ink reservoir is caused to oscillate in pressure and drops of ink are ejected from said nozzle at an ejection frequency that is substantially half the frequency of the oscillating pressure of said ink within said ink reservoir.

8. A shuttered ink jet nozzle as claimed in claim 2 wherein said shuttered device comprises a plurality of shutter plates covering a corresponding plurality of shutter holes allowing the flow of ink between said ink chamber and said ink reservoir.

9. A shuttered ink jet nozzle as claimed in claim 2 wherein said ink chamber is formed by a crystallographic etch of a silicon wafer.

10. An array of ink jet nozzles with each nozzle as claimed in claim 1 wherein the nozzles are grouped into phase groups and each phase group is activated in turn so as to reduce pressure requirements in an ink jet reservoir.

12. An ink jet printhead as claimed in claim 1, further comprising an array of ink ejection nozzles wherein the nozzles are grouped into phase groups and each phase group is activated in turn so as to reduce pressure requirements in said ink reservoir.

11. A method of operation of an ink jet printead having a shutter and a nozzle chamber and an ink reservoir, the ink reservoir having an oscillating ink pressure, comprising the steps of:

(a) opening the shutter to cause ink to be ejected from the nozzle chamber resulting in a reduction of ink in said nozzle chamber followed by

(b) leaving the shutter open during a subsequent high pressure of said ink pressure so as to allow said nozzle chamber to refill, followed by

(c) closing said shutter at the end of a high pressure cycle so as to restrict back flow of ink from said nozzle chamber to said ink reservoir.

13. An ink jet printer having a plurality of ink chambers, each ink chamber having an ink ejection nozzle for ejecting ink from said chamber, an ink reservoir for the supply of ink to said chamber and a shutter located between the reservoir and the chamber and including an actuator to move said shutter between closed and open positions and a linear spring to amplify said movement of the shutter to allow ejection of ink from said chamber via said ink ejection nozzle onto print media on demand.

14. An ink jet printhead comprising:

(a) an ink chamber having an ink ejection nozzle for the ejection of ink from said ink chamber;

(b) an ink reservoir for the supply of ink to said ink chamber under pressure;

(c) at least one linear spring; and

(d) a shutter device located between said ink reservoir and said ink chamber and interacting with said at least one linear spring so as to allow or restrict flowing of ink between the ink chamber and ink reservoir to thereby cause ink to be ejected from said chamber, said shutter device being actuated on demand and having its movement amplified by said linear spring, wherein said shutter device comprises an electromagnetic coil mechanism attracting a magnetic bar and wherein said coil is anchored to a silicon wafer and said magnetic bar is connected to a shutter plate adapted to open and close over a series of shutter holes allowing fluid communication between said ink reservoir and said ink chamber, and wherein said linear spring is anchored on one side of said ink chamber and said electromagnetic coil is anchored to an opposite side of said ink chamber, the shutter plate operable between said linear spring anchor and said electromagnetic anchor and wherein ink in said ink reservoir is caused to oscillate in pressure and drops of ink are ejected from said nozzle at an ejection frequency that is substantially half the frequency of the oscillating pressure of said ink within said ink reservoir, and wherein said ink chamber is formed by a crystallographic etch of said silicon wafer.