Printhead with barrier at chamber inlet

• US 7,568,788 B2
• Filed: 10/28/2007
• Issued: 08/04/2009
• 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): Do; An H
• Application Number:
  US11/926,109
• Publication Number:
  US 20080043066A1
• Time in Patent Office: 646 Days
• Field of Search: 347/54, 347/56, 347/65
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 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 2/14427 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 2/1626 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 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 : Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 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 2002/14443 : Nozzle guard
• 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: G07F 7/08 : by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/086 : by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/12 : Card verification
• 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
• CPC Class Codes: Y10T 29/49083 : Heater type
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49169 : Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49172 : by molding of insulating material
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

An inkjet printhead that has an array of ink ejection devices, each ink ejection device having a chamber for holding a quantity of ink, an inlet in fluid communication with the chamber, an actuator disposed in the chambers respectively, a nozzle aperture in fluid communication with each of the chambers respectively. The inlet defines a flow path into the chamber and has a barrier structure extending through the flow path. The barrier structure creates a flow constriction that traps contaminant in the ink flow.

Claims

1. A printhead for an inkjet printer, the printhead comprising:

an array of ink ejection devices, each ink ejection device having a chamber for holding a quantity of ink, the chamber being partially defined by at least one sidewall, an inlet in fluid communication with the chamber, an actuator disposed in the chambers respectively, a nozzle in fluid communication with each of the chambers respectively, the nozzle is formed in a nozzle plate on the printhead exterior;

wherein,

the inlet defines a flow path into the chamber and has a column feature extending through the flow path, the column feature and the at least one sidewall being integrally formed with the nozzle plate.

2. A printhead according to claim 1 wherein the actuator is configured to displace a surface within the chamber to eject ink from the nozzle.

3. A printhead according to claim 2 wherein the actuator has a heater element for displacing the surface using thermal expansion.

4. A printhead according to claim 3 wherein the surface is positioned in the chamber such that it opposes the nozzle and the flow path from the inlet feeds ink between the nozzle and the surface of the actuator.

5. A printhead according to claim 4 wherein the surface defines a wall of the chamber opposite the nozzle.

6. A printhead according to claim 5 wherein the surface is formed from material including polytetrafluoroethylene.

7. A printhead according to claim 6 wherein during use, the surface reduces the chamber volume to eject ink from the nozzle.

8. A printhead according to claim 7 wherein during use, the surface increases the chamber volume as the actuator returns to its quiescent position after ejecting ink in order to draw refill ink through the baffler structure in the inlet.

9. A printhead according to claim 8 wherein the surface has a quadrilateral geometry and is fixed at two opposing parallel sides such that the surface buckles into the chamber when during actuation, and flattens when returning to its quiescent state.

10. A printhead according to claim 9 wherein the heater element is a conductor with a serpentine geometry extending across most of the surface.

11. A printhead according to claim 10 further comprising an air space on non-ink contacting side of the surface.

12. A printhead according to claim 11 wherein the air space is vented to atmosphere.

13. A printhead according to claim 12 wherein the non-ink contacting side of the surface is hydrophobic for maintaining the air space.

14. A printhead according to claim 13 wherein the column feature creates a flow restriction for the refill ink flow to damp oscillations in ink in the chamber immediately after refill.

15. A printhead according to claim 1 wherein the column feature in a grille for filtering contaminants out of the ink flow into the chamber.