Ink jet printhead with moveable ejection nozzles

• US 6,886,918 B2
• Filed: 03/25/2004
• Issued: 05/03/2005
• Est. Priority Date: 06/09/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Primary Examiner(s): Meier, Stephen D.
• Assistant Examiner(s): Do, An H.
• Application Number:
  US10/808,582
• Publication Number:
  US 20040179067A1
• Time in Patent Office: 404 Days
• Field of Search: 347/20, 347 40- 43, 347/47, 347/48, 347/54, 347/56, 347 61- 65, 347 68- 72
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/1433 Structure of nozzle plates
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• 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 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• 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 2/1648 Production of print heads with thermal bend detached actuators
• 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: B41J 2002/14435 Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14475 characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 : with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

An inkjet printhead with an array of ink chambers, each with an outer wall defining an ink ejection port and having at least one actuator. The outer wall faces the print media substrate during use wherein the actuator move the ejection port away from the media substrate in order eject ink through the port. This arrangement does not have any actuators within the chamber to slow ink refill and the return of the outer wall to its quiescent state assists ink refill.

Claims

1. An inkjet printhead for printing on a media substrate, the printhead comprising:

a wafer substrate defining a plurality of nozzle chambers for storing ink to be ejected, each of the nozzle chambers having an outer wall that faces the media substrate during use, the wall having an ink ejection port and a plurality of actuators in the wall for moving the ink ejection port away from the media substrate to eject ink from the corresponding nozzle chamber via the ink ejection port, wherein the actuators include a surface which bends inwards away from the centre of the nozzle chamber upon actuation, and wherein the actuators are actuated by means of a thermal actuator device having a conductive resistive heating element encased within a material having a high coefficient of thermal expansion.

2. An inkjet printhead according to claim 1 wherein the element can be serpentine to allow for substantially unhindered expansion of the material.

3. An inkjet printhead according to claim 2 wherein the actuators are arranged radially around the ejection port.

4. An inkjet printhead according to claim 3 wherein the actuators form a membrane between the nozzle chamber and an external atmosphere of the arrangement and the actuators bend away from the external atmosphere to cause an increase in pressure within the nozzle chamber thereby initiating a consequential ejection of ink from the nozzle chamber.

5. An inkjet printhead according to claim 4 wherein the actuators bend away from a central axis of the nozzle chamber.

6. An inkjet printhead according to claim 5 wherein the ink chambers are formed on the wafer substrate utilizing micro-electro mechanical techniques and further comprise an ink supply channel in communication with the nozzle chamber.

7. An inkjet printhead according to claim 6 wherein the ink supply channel is etched through the wafer.

8. An inkjet printhead according to claim 7 wherein each of the ink chambers include a series of struts which support the ejection port.

9. An inkjet printhead according to claim 8 wherein the ink chambers are formed adjacent each other so as to form a pagewidth printhead.