Printhead having nozzles with stacked capacitive actuators

• US 8,079,670 B2
• Filed: 05/04/2010
• Issued: 12/20/2011
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Stephens, Juanita D
• Application Number:
  US12/773,761
• Publication Number:
  US 20100214367A1
• Time in Patent Office: 595 Days
• Field of Search: 347/20, 347/44, 347/47, 347/54, 347/56, 347/37, 347 61- 65, 347/67
• 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 2/1626 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 2/16585 for paper-width or non-reciprocating print heads
• 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: 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 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

A printhead is provided having a fluid ejection nozzles which each have a substrate, a layer of drive circuitry deposited on the substrate, and subsequent etchant layers deposited on the drive circuitry to define a nozzle chamber with walls and a roof structure defining a fluid ejection port. Each nozzle also has a stacked capacitive actuator arranged in the chamber. The actuator has alternate electrode plates sandwiched between a compressible polymer, wherein activation of the stacked actuator draws the electrode plates together to compress the polymer storing energy therein, with subsequent de-activation releasing the energy to eject fluid within the chamber from the ejection port.

Claims

1. A printhead comprising a plurality of fluid ejection nozzles, each nozzle comprising:

a substrate;

a layer of drive circuitry deposited on the substrate;

subsequent etchant layers deposited on the drive circuitry to define a nozzle chamber with walls and a roof structure defining a fluid ejection port; and

a stacked capacitive actuator arranged in said chamber, said actuator having electrode plates sandwiched alternately between a compressible polymer, wherein activation of the stacked actuator draws the electrode plates together to compress the polymer storing energy therein, with subsequent de-activation releasing said energy to eject fluid within said chamber from the ejection port.

2. The printhead of claim 1, wherein the electrode actuator is constructed according to chemical vapor deposition (CVD) techniques.

3. The printhead of claim 1, wherein the electrode plates comprise separate metals.

4. The printhead of claim 3, wherein the electrodes are comprised of alternating aluminium and tantalum plates.

5. The printhead of claim 4, wherein the alternating metal plates define electrodes on opposite sides of the actuator, said corresponding electrodes electrically isolated from each other and connected to the drive circuitry.

6. The printhead of claim 1, wherein the layer of drive circuitry is a two-level metal CMOS layer.

7. The printhead of claim 1, wherein the polymer comprises styrene-ethylene-butylene-styrene block copolymer.