Inkjet printhead with thermal actuator coil

• US 7,901,048 B2
• Filed: 05/31/2009
• Issued: 03/08/2011
• 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): Do; An H
• Application Number:
  US12/475,564
• Publication Number:
  US 20090237460A1
• Time in Patent Office: 646 Days
• Field of Search: 347/54, 347/56, 347/65
• 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 2/1637 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 2/1643 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 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• 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 19/073 : Special arrangements for circuits, e.g. for protecting identification code in memory protection against unauthorised use of computer memory G06F12/14
• 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

Provided is a printhead for an inkjet printer. The printhead has a plurality of micro-electromechanical ejection mechanisms arranged in a wafer substrate, with each mechanism having chamber walls and a roof formed on top of said substrate to define an ink chamber. One wall of the chamber defines a slot therein. The mechanism also includes an ink supply channel defined through the substrate to said chamber. The mechanism includes a bi-layer thermal actuator coil fast with the substrate and ending in a strut extending through the slot, said strut fast with a paddle device within the chamber.

Claims

1. A printhead for an inkjet printer, the printhead having a plurality of micro-electromechanical ejection mechanisms arranged in a wafer substrate, each mechanism comprising:

an ink chamber formed on said substrate, the ink chamber having an ink ejection nozzle formed in a roof thereof;

a paddle device arranged inside the ink chamber; and

a bi-layer thermal actuator coil fast with the substrate and outside the ink chamber, the thermal actuator coil being connected to the paddle device, wherein expansion of the thermal coil displaces the paddle device causing ejection of ink through the ink ejection nozzle.

2. The printhead as claimed in claim 1, wherein the bi-layer thermal actuator coil includes a first layer manufactured from a non-conductive material and a second layer manufactured from a conductive material, wherein applying current to the second later causes the thermal actuator coil to expand.

3. The printhead as claimed in claim 2, wherein the first layer is manufactured from glass and the second layer is manufactured from titanium diboride.

4. The printhead as claimed in claim 3, wherein the substrate includes a CMOS layer arranged in electrical communication with the second layer.

5. The printhead as claimed in claim 1, wherein the thermal actuator coil is connected to the paddle device by a strut extending through an aperture in a side wall of the ink chamber.

6. The printhead as claimed in claim 5, wherein the strut and the aperture are treated to be hydrophobic.

7. The printhead as claimed in claim 5, wherein the aperture has a thin elongate form.

8. The printhead as claimed in claim 1, wherein a rim is formed around a perimeter of the ink nozzle, the rim being configured to exploit surface tension characteristics of ink in the chamber to prevent ink from flowing out of the chamber.