EP1640162A1 - Inkjet nozzle arrangement having paddle forming a portion of a wall - Google Patents

Inkjet nozzle arrangement having paddle forming a portion of a wall Download PDF

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Publication number
EP1640162A1
EP1640162A1 EP05109701A EP05109701A EP1640162A1 EP 1640162 A1 EP1640162 A1 EP 1640162A1 EP 05109701 A EP05109701 A EP 05109701A EP 05109701 A EP05109701 A EP 05109701A EP 1640162 A1 EP1640162 A1 EP 1640162A1
Authority
EP
European Patent Office
Prior art keywords
ink
nozzle
layer
actuator
wafer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP05109701A
Other languages
German (de)
French (fr)
Other versions
EP1640162B1 (en
Inventor
Kia Silverbrook
Gregory Mcavoy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Silverbrook Research Pty Ltd
Original Assignee
Silverbrook Research Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to AUPO8043A priority Critical patent/AUPO804397A0/en
Priority to AUPO8050A priority patent/AUPO805097A0/en
Priority to AUPO8011A priority patent/AUPO801197A0/en
Priority to AUPO7951A priority patent/AUPO795197A0/en
Priority to AUPO8068A priority patent/AUPO806897A0/en
Priority to AUPO8002A priority patent/AUPO800297A0/en
Priority to AUPO8006A priority patent/AUPO800697A0/en
Priority to AUPO8056A priority patent/AUPO805697A0/en
Priority to AUPO8039A priority patent/AUPO803997A0/en
Priority to AUPO8075A priority patent/AUPO807597A0/en
Priority to AUPO8007A priority patent/AUPO800797A0/en
Priority to AUPO7941A priority patent/AUPO794197A0/en
Priority to AUPO8034A priority patent/AUPO803497A0/en
Priority to AUPO8001A priority patent/AUPO800197A0/en
Priority to AUPO8040A priority patent/AUPO804097A0/en
Priority to AUPO8074A priority patent/AUPO807497A0/en
Priority to AUPO8033A priority patent/AUPO803397A0/en
Priority to AUPO8010A priority patent/AUPO801097A0/en
Priority to AUPO8042A priority patent/AUPO804297A0/en
Priority to AUPO8008A priority patent/AUPO800897A0/en
Priority to AUPO7945A priority patent/AUPO794597A0/en
Priority to AUPO7944A priority patent/AUPO794497A0/en
Priority to AUPO8038A priority patent/AUPO803897A0/en
Priority to AUPO8064A priority patent/AUPO806497A0/en
Priority to AUPO8051A priority patent/AUPO805197A0/en
Priority to AUPO8052A priority patent/AUPO805297A0/en
Priority to AUPO8062A priority patent/AUPO806297A0/en
Priority to AUPO8078A priority patent/AUPO807897A0/en
Priority to AUPO7943A priority patent/AUPO794397A0/en
Priority to AUPO7946A priority patent/AUPO794697A0/en
Priority to AUPO8045A priority patent/AUPO804597A0/en
Priority to AUPO7947A priority patent/AUPO794797A0/en
Priority to AUPO7937A priority patent/AUPO793797A0/en
Priority to AUPO7952A priority patent/AUPO795297A0/en
Priority to AUPO8037A priority patent/AUPO803797A0/en
Priority to AUPO7933A priority patent/AUPO793397A0/en
Priority to AUPO8079A priority patent/AUPO807997A0/en
Priority to AUPO8057A priority patent/AUPO805797A0/en
Priority to AUPO8046A priority patent/AUPO804697A0/en
Priority to AUPO7948A priority patent/AUPO794897A0/en
Priority to AUPO8503A priority patent/AUPO850397A0/en
Priority to AUPO9389A priority patent/AUPO938997A0/en
Priority to AUPO9391A priority patent/AUPO939197A0/en
Priority to AUPO9390A priority patent/AUPO939097A0/en
Priority to AUPO9392A priority patent/AUPO939297A0/en
Priority to AUPO9393A priority patent/AUPO939397A0/en
Priority to AUPP0891A priority patent/AUPP089197A0/en
Priority to AUPP0873A priority patent/AUPP087397A0/en
Priority to AUPP0875A priority patent/AUPP087597A0/en
Priority to AUPP0874A priority patent/AUPP087497A0/en
Priority to AUPP0890A priority patent/AUPP089097A0/en
Priority to AUPP0892A priority patent/AUPP089297A0/en
Priority to AUPP0889A priority patent/AUPP088997A0/en
Priority to AUPP0872A priority patent/AUPP087297A0/en
Priority to AUPP0882A priority patent/AUPP088297A0/en
Priority to AUPP0888A priority patent/AUPP088897A0/en
Priority to AUPP0894A priority patent/AUPP089497A0/en
Priority to AUPP0893A priority patent/AUPP089397A0/en
Priority to AUPP1398A priority patent/AUPP139898A0/en
Priority to AUPP1396A priority patent/AUPP139698A0/en
Priority to AUPP2593A priority patent/AUPP259398A0/en
Priority to AUPP2591A priority patent/AUPP259198A0/en
Priority to AUPP2592A priority patent/AUPP259298A0/en
Priority to AUPP3987A priority patent/AUPP398798A0/en
Priority to AUPP3989A priority patent/AUPP398998A0/en
Priority to AUPP3990A priority patent/AUPP399098A0/en
Priority to AUPP3986A priority patent/AUPP398698A0/en
Priority to AUPP3985A priority patent/AUPP398598A0/en
Priority to AUPP3991A priority patent/AUPP399198A0/en
Priority to AUPP3984A priority patent/AUPP398498A0/en
Priority to AUPP3983A priority patent/AUPP398398A0/en
Priority to EP19980933352 priority patent/EP0999934B1/en
Application filed by Silverbrook Research Pty Ltd filed Critical Silverbrook Research Pty Ltd
Publication of EP1640162A1 publication Critical patent/EP1640162A1/en
Application granted granted Critical
Publication of EP1640162B1 publication Critical patent/EP1640162B1/en
Anticipated expiration legal-status Critical
Application status is Not-in-force legal-status Critical

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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J3/00Typewriters or selective printing or marking mechanisms, e.g. ink-jet printers, thermal printers characterised by the purpose for which they are constructed
    • B41J3/44Typewriters or selective printing mechanisms having dual functions or combined with, or coupled to, apparatus performing other functions
    • B41J3/445Printers integrated in other types of apparatus, e.g. printers integrated in cameras
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/14Structure thereof only for on-demand ink jet heads
    • B41J2/14314Structure of ink jet print heads with electrostatically actuated membrane
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/14Structure thereof only for on-demand ink jet heads
    • B41J2/14427Structure of ink jet print heads with thermal bend detached actuators
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1623Production of nozzles manufacturing processes bonding and adhesion
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1626Production of nozzles manufacturing processes etching
    • B41J2/1628Production of nozzles manufacturing processes etching dry etching
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1626Production of nozzles manufacturing processes etching
    • B41J2/1629Production of nozzles manufacturing processes etching wet etching
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1631Production of nozzles manufacturing processes photolithography
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1632Production of nozzles manufacturing processes machining
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1635Production of nozzles manufacturing processes dividing the wafer into individual chips
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/1637Production of nozzles manufacturing processes molding
    • B41J2/1639Production of nozzles manufacturing processes molding sacrificial molding
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/164Production of nozzles manufacturing processes thin film formation
    • B41J2/1642Production of nozzles manufacturing processes thin film formation thin film formation by CVD [chemical vapor deposition]
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/164Production of nozzles manufacturing processes thin film formation
    • B41J2/1643Production of nozzles manufacturing processes thin film formation thin film formation by plating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/164Production of nozzles manufacturing processes thin film formation
    • B41J2/1645Production of nozzles manufacturing processes thin film formation thin film formation by spincoating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1621Production of nozzles manufacturing processes
    • B41J2/164Production of nozzles manufacturing processes thin film formation
    • B41J2/1646Production of nozzles manufacturing processes thin film formation thin film formation by sputtering
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/135Nozzles
    • B41J2/16Production of nozzles
    • B41J2/1648Production of print heads with thermal bend detached actuators
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/17Ink jet characterised by ink handling
    • B41J2/175Ink supply systems ; Circuit parts therefor
    • B41J2/17596Ink pumps, ink valves
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, e.g. INK-JET PRINTERS, THERMAL PRINTERS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01Ink jet
    • B41J2/015Ink jet characterised by the jet generation process
    • B41J2/04Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2002/041Electromagnetic transducer

Abstract

An inkjet nozzle arrangement for a printhead is provided. The nozzle arrangement comprises a nozzle chamber for storing ink to be ejected, at least one moveable actuator paddle forming at least a portion of a first wall of said nozzle chamber, and
an ink ejection nozzle defined in the first wall. Actuation of the actuator paddle causes ejection of ink from the nozzle.

Description

    Field of Invention
  • The present invention relates to the field of ink jet printing systems.
  • Background of the Art
  • Many different types of printing have been invented, a large number of which are presently in use. The known forms of print have a variety of methods for marking the print media with a relevant marking media. Commonly used forms of printing include offset printing, laser printing and copying devices, dot matrix type impact printers, thermal paper printers, film recorders, thermal wax printers, dye sublimation printers and ink jet printers both of the drop on demand and continuous flow type. Each type of printer has its own advantages and problems when considering cost, speed, quality, reliability, simplicity of construction and operation etc.
  • In recent years, the field of ink jet printing, wherein each individual pixel of ink is derived from one or more ink nozzles has become increasingly popular primarily due to its inexpensive and versatile nature.
  • Many different techniques of ink jet printing have been invented. For a survey of the field, reference is made to an article by J Moore, "Non-Impact Printing: Introduction and Historical Perspective", Output Hard Copy Devices, Editors R Dubeck and S Sherr, pages 207 - 220 (1988).
  • Ink Jet printers themselves come in many different types. The utilisation of a continuous stream ink in ink jet printing appears to date back to at least 1929 wherein US Patent No. 1941001 by Hansell discloses a simple form of continuous stream electro-static ink jet printing.
  • US Patent 3596275 by Sweet also discloses a process of a continuous ink jet printing including the step wherein the ink jet stream is modulated by a high frequency electro-static field so as to cause drop separation. This technique is still utilised by several manufacturers including Elmjet and Scitex (see also US Patent No. 3373437 by Sweet et al)
  • Piezo-electric ink jet printers are also one form of commonly utilised ink jet printing device. Piezo-electric systems are disclosed by Kyser et. al. in US Patent No. 3946398 (1970) which utilises a diaphragm mode of operation, by Zolten in US Patent 3683212 (1970) which discloses a squeeze mode of operation of a piezo electric crystal, Stemme in US Patent No. 3747120 (1972) discloses a bend mode of piezo-electric operation, Howkins in US Patent No. 4459601 discloses a Piezo electric push mode actuation of the ink jet stream and Fischbeck in US 4584590 which discloses a sheer mode type of piezo-electric transducer element.
  • Recently, thermal ink jet printing has become an extremely popular form of ink jet printing. The ink jet printing techniques include those disclosed by Endo et al in GB 2007162 (1979) and Vaught et al in US Patent 4490728. Both the aforementioned references disclosed ink jet printing techniques rely upon the activation of an electrothermal actuator which results in the creation of a bubble in a constricted space, such as a nozzle, which thereby causes the ejection of ink from an aperture connected to the confined space onto a relevant print media. Printing devices utilising the electro-thermal actuator are manufactured by manufacturers such as Canon and Hewlett Packard.
  • As can be seen from the foregoing, many different types of printing technologies are available. Ideally, a printing technology should have a number of desirable attributes. These include inexpensive construction and operation, high speed operation, safe and continuous long term operation etc. Each technology may have its own advantages and disadvantages in the areas of cost, speed, quality, reliability, power usage, simplicity of construction operation, durability and consumables.
  • Many ink jet printing mechanisms are known. Unfortunately, in mass production techniques, the production of ink jet heads is quite difficult. For example, often, the orifice or nozzle plate is constructed separately from the ink supply and ink ejection mechanism and bonded to the mechanism at a later stage (Hewlett-Packard Journal, Vol. 36 no 5, pp33-37 (1985)). These separate material processing steps required in handling such precision devices often adds a substantially expense in manufacturing.
  • Additionally, side shooting ink jet technologies (U.S. Patent No. 4,899,181) are often used but again, this limit the amount of mass production throughput given any particular capital investment.
  • Additionally, more esoteric techniques are also often utilised. These can include electroforming of nickel stage (Hewlett-Packard Journal, Vol. 36 no 5, pp33-37 (1985)), electro-discharge machining, laser ablation (U.S. Patent No. 5,208,604), micro-punching, etc.
  • The utilisation of the above techniques is likely to add substantial expense to the mass production of ink jet print heads and therefore add substantially to their final cost.
  • It would therefore be desirable if an efficient system for the mass production of ink jet print heads could be developed.
  • Further, during the construction of micro electromechanical systems, it is common to utilize a sacrificial material to build up a mechanical system, within the sacrificial material being subsequently etched away so as to release the required mechanical structure. For example, a suitable common sacrificial material includes silicon dioxide which can be etched away in hydrofluoric acid. MEMS devices are often constructed on silicon wafers having integral electronics such as, for example, using a multi-level metal CMOS layer. Unfortunately, the CMOS process includes the construction of multiple layers which may include the utilization of materials which can be attacked by the sacrificial etchant. This often necessitates the construction of passivation layers using extra processing steps so as to protect other layers from possible unwanted attack by a sacrificial etchant.
  • In micro-electro mechanical system, it is often necessary to provide for the movement of objects. In particular, it is often necessary to pivot objects in addition to providing for fulcrum arrangements where a first movement of one end of the fulcrum is translated into a corresponding measurement of a second end of the fulcrum. Obviously, such arrangements are often fundamental to mechanical apparatuses.
  • Further, When constructing large integrated circuits or micro-electro mechanical systems, it is often necessary to interconnect a large number of wire to the final integrated circuit device. To this end, normally, a large number of bond pads are provided on the surface of a chip for the attachment of wires thereto. With the utilization of bond pads normally certain minimal spacings are utilized in accordance with the design technologies utilised. Where are large number of interconnects are required, an excessive amount of on chip real estate is required for providing bond pads. It is therefore desirable to minimize the amount of real estate provided for bond pads whilst ensuring the highest degree of accuracy of registration for automated attachment of interconnects such as a tape automated bonding (TAB) to the surface of a device.
  • Summary of the invention
  • The present invention relates to ink jet printing and in particular, discloses a new form of ink jet printer which utilises a planar thermoelastic bend actuator to eject ink from a nozzle chamber.
  • In accordance with a first aspect of the present invention an ink jet nozzle is provided comprising a nozzle chamber having an ink ejection port in one wall of the chamber, an ink supply source interconnected to the nozzle chamber and a thermal actuator activated to eject ink from the nozzle chamber via the ink ejection port. Further, the thermal actuator comprises a lower planar surface constructed from a highly conductive material interconnected to an upper planar material constructed from an electrically resistive material such that upon passing a current between the planar surface, the thermal actuator is caused to bend towards the ink ejection port so as to thereby cause the ejection of ink from the ink ejection port. The actuator is attached to a substrate and further includes a stiff paddle portion which increases the degree of bending of the actuator near the point where it is attached to the substrate. Preferably, the stiff paddle is formed of silicon nitride. Advantageously, the actuator further includes an expansion coating having a high coefficient of thermal expansion on top of the upper planar surface so as to increase the amount of bending of the actuator. The expansion coating can comprise substantially polytetrafluoroethylene. Between the upper and lower planar surfaces there is provided a gap, constructed through the utilisation of a sacrificial material which is deposited and subsequently etched away so as to leave the gap. Further, the upper planar surface includes a plurality of etchant holes provided to allow a more rapid etching of the sacrificial layer during construction. Advantageously, the upper planar surface of the actuator comprises substantially Indium Tin Oxide (ITO) whereas the lower planar surface of the actuator comprises substantially a metal layer. Both surfaces are further coated with a passivation material as required. The ink jet nozzle construction can be formed on a silicon wafer utilising micro-electro mechanical systems construction techniques.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle chamber having an ink ejection port in one wall of the chamber and an ink supply source interconnected to the chamber. The ink jet nozzle chamber can comprise two actuators the first actuator for ejecting ink from the ink ejection port and a second actuator for pumping ink into the chamber from the ink supply source after the first actuator has caused the ejection of ink from the nozzle chamber. The actuators can utilize thermal bending caused by a conductive heater element encased within a material having a high coefficient of thermal expansion whereby the actuators operate by means of electrical heating by the heater elements. The heater elements can be of serpentine form and concertinaed upon heating so as to allow substantially unhindered expansion of said actuation material during heating. The first actuator is arranged substantially opposite the ink ejection port and both actuators form segments of the nozzle chamber wall opposite the ink ejection port and between the nozzle chamber and the ink supply source. The method for driving the actuators for the ejection of ink from the ink ejection port comprises utilizing the first actuator to eject ink from the ejection port and utilizing the second actuator to pump ink towards the ink ejection port so as to rapidly refill the nozzle chamber around the area of the ink ejection port. The method for driving the actuators can comprise the following steps:
    • (a) activating the first actuator to eject ink from the ink ejection port;
    • (b) deactivating the first actuator so as to cause a portion of the ejected ink to break off from a main body of ink within the nozzle chamber;
    • (c) activation of the second actuator to pump ink towards the ink ejection port so as to rapidly refill the nozzle chamber around the area of the ink ejection port;
    • (d) activating the first actuator to eject ink from the ink ejection port whilst simultaneously deactivating the second actuator so as to return to its quiescent position; or otherwise
    • (e) deactivating the second actuator to return to its quiescent position.
  • The material of the two actuators having a high coefficient of thermal expansion can comprise substantially polytetrafluoroethylene and the surface of the actuators are treated to make them hydrophilic. Preferably, the heater material embedded in the thermal actuators comprises substantially copper. Further, the actuators are formed by utilization of a sacrificial material layer which is etched away to release the actuators. The ink jet nozzle chamber can be formed from crystallographic etching of a silicon substrate. Further, the thermal actuators are attached to a substrate at one end and the heating of the actuators is primarily near the attached end of the devices. The ink jet nozzle is preferably constructed via fabrication from a silicon wafer utilizing semiconductor fabrication techniques.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle comprising an ink ejection port for the ejection of ink, an ink supply with an oscillating ink pressure interconnected to the ink ejection port, a shutter mechanism interconnected between the ink supply and the ink ejection port, which blocks the ink ejection port, and an actuator mechanism for moving the shutter mechanism on demand away from the ink ejection port so as to allow for the ejection of ink on demand from the ink ejection port.
  • Further, the actuator can comprise a thermal actuator which is activated by the heating of one side of the actuator. Preferably the actuator has a coiled form and is uncoiled upon heating. The actuator can include a serpentine heater element encased in a material having a high coefficient of thermal expansion. The serpentine heater can concertina upon heating. Advantageously, the actuator includes a thick return trace for the serpentine heater element. The material in which the serpentine heater element is encased can comprise polytetrafluoro-ethylene. The actuator can be formed within a nozzle chamber which is formed on a silicon wafer and ink is supplied to the ejection port through channels etched through the silicon wafer.
  • In accordance with a further aspect of the present invention an ink jet nozzle is provided comprising a nozzle chamber having an ink ejection port in one wall of the chamber, an ink supply under a varying pressure interconnected to the nozzle chamber, and a shutter means located between the nozzle chamber and the ink supply source, which is activated on demand to allow ink to pass through the shutter means and to thereby cause ink to be ejected from the nozzle chamber. Further, the shutter means is actuated by means of a buckle actuation mechanism attached to a shutter plate.
  • The actuation means can comprise a serpentine conductive material encased within an expansive material having a high coefficient of thermal expansion such that, upon heating of the serpentine conductive material, the material concertinas so as to expand at a similar rate to the expansive material. Preferably the expansive material comprises substantially polytetrafluoroethylene, and, preferably, the serpentine conductive material comprises substantially copper. The buckling of the actuator can be between stable end connector portions constructed from the conductive material. In its quiescent state the shutter means is closed.
  • Advantageously the ink supply source includes an ink supply channel interconnecting the shutter means by means of a through hole etching of the silicon wafer. The through hole etching is produced preferably by high density low pressure plasma etching of the silicon wafer. Further the ink supply source is driven with a substantially oscillating ink pressure.
  • In accordance with a further aspect of the present invention, there is provided a method of ejecting ink from a nozzle chamber in an ink jet nozzle that comprises a nozzle chamber having an ink ejection port in one wall of the chamber, an ink supply source interconnected to the nozzle chamber, which includes an ink supply under varying pressure, and a shutter means located between the nozzle chamber and the ink supply source. The shutter is activated on demand to allow ink to pass through the shutter means and the thereby cause ink to be ejected from the nozzle chamber. Preferably the shutter means is actuated by means of a buckle actuation mechanism attached to a shutter plate. The method can comprise the following steps:
    • a) activating the shutter to an open position during a high pressure time of the varying pressure so as to cause the ejection of ink from the port;
    • b) driving the pressure to a low pressure state so as to cause drop separation of ejected ink;
    • c) keeping the shutter open during a subsequent high pressure time of the varying pressure sufficient to cause the nozzle chamber to be rapidly refilled;
    • d) closing the shutter upon refill of the nozzle chamber such that the chamber is ready for the subsequent ejection of ink upon subsequent opening of the shutter.
  • In accordance with a further aspect of the present invention, there is provided an ink jet printing device comprising an ink chamber having an oscillating ink pressure, a plurality of nozzle apparatuses in fluid communication with the ink chamber which include a grilled shutter having a first open state permitting the expulsion of ink from the nozzle apparatus and a second closed state substantially restricting the expulsion of ink from the nozzle chamber, and a shutter activation means adapted to drive, on demand, the grilled shutter from a first to a second of these states. Further, the nozzle apparatus can include a locking means adapted to lock the grilled shutter in an open or closed state as required.
  • The method of operating the ink jet printing device of the type in accordance with the present invention can comprise the following steps:
    • opening the grilled shutter during a first high pressure period in the ink chamber;
    • utilizing the high pressure period and a following low pressure period for the expulsion of ink from the nozzle apparatus;
    • utilizing a subsequent high pressure period for the refilling of the nozzle apparatus; and
    • closing the grilled shutter until such time as further ink is required to be expelled from the nozzle apparatus.
  • Preferably, the ink jet printing device has a shutter activation means that comprises a thermocouple device. The thermocouple device can consist of two arms, one arm having a thermal jacket of low thermal conductivity. Advantageously, the arm having the thermal jacket includes a thinned portion adapted to increase the travel of the thermocouple upon activation.
  • In the ink jet printing device constructed in accordance with this aspect of the present invention, both the magnitude and frequency of the oscillating ink pressure in the ink chamber can be altered. Preferably, the size and period of each cycle can be scaled in accordance with such pre-calculated factors such as the number of nozzles ejecting ink and the pressure requirements for nozzle refill with different inks.
  • In accordance with a further aspect of the present invention there is provided an ink jet nozzle comprising a nozzle chamber having an ink ejection port in one wall of the chamber and a thermal actuator unit activated to eject ink from the nozzle chamber via the ink ejection port, the thermal actuator unit comprises a plurality of the thermal actuator petal devices arranged around a central stem so that upon activation of the thermal actuator petal devices, the devices bend in unison, thereby initiating the ejection of ink from the nozzle chamber. Preferably the thermal actuator unit is located opposite the ink ejection port and the petal devices bent generally in the direction of the ink ejection port. The thermal actuator petal devices can comprise a first material having a high coefficient of thermal expansion surrounding a second material which conducts resistively so as to provide for heating of the first material. Further the second material can be constructed so as to concertina upon expansion of the first material. Advantageously an air bubble forms under the thermal actuator during operation. The first material of the thermal actuator petal can comprise substantially polytetrafluoroethylene, and the second material can comprise substantially copper. Upon activation of the thermal actuator unit, the space between adjacent petal devices is reduced. Advantageously the actuator petal devices are attached to a substrate and the heating of the petal devices is primarily near the attached end of the device. Further, the outer surface of the ink chamber can include a plurality of etchant holes provided so as to allow a more rapid etching of sacrificial layers during construction.
  • In accordance with a further aspect of the present invention, there is provided an ink jet printing device comprising an ink chamber containing ink subject to a periodic pressure variation, at least one ink jet nozzle apparatus which comprises a nozzle chamber having an aperture for the ejection of ink, a moveable shutter having a closed position covering the nozzle chamber and an open position allowing the nozzle chamber to be in fluid communication with the ink chamber and an actuation means responsive to a control signal and adapted to move the moveable shutter from a first of the positions to a second position upon activation of the control signal.
  • Preferably the first position is the closed position and the second position is the open position. The actuator means can comprise a coiled thermal actuator, which is actuated via one of differing resistivities, differing cross-sectional areas, differing thermal expansion or differing thermal conductivities in the thermal actuator. Advantageously, the periodic pressure variation in the ink jet printing device is derived from an ultrasonic transducer in fluid communication with the ink in the ink chamber.
  • In accordance with a further aspect of the present invention there is provided a method of ejecting ink from a nozzle chamber in fluid communication with an ink reservoir, having a shutter controlling the flow of ink from the ink reservoir to the nozzle chamber, which comprises the steps of:
    • a) applying a periodic pressure wave to the ink reservoir, and opening the shutter at a first predetermined time to allow the ejection of ink from the nozzle chamber.
    • b) maintaining the shutter in an open position to allow the ink chamber to refill the nozzle chamber, and closing the shutter upon refilling of the nozzle chamber.
  • Preferably the method of ejecting ink from a nozzle comprises periodic pressure waves including periods of negative pressure within the ink chamber and the shutter remains open during the periods of negative pressure so as to cause separation of ejected ink from the nozzle chamber. The period of negative pressure is followed by a period of positive pressure in which the nozzle chamber is refilled with ink.
  • In accordance with a further aspect of the present invention there is provided an ink jet nozzle arrangement comprising at least one nozzle chamber having an ink ejection port at one wall thereof and a plurality of vane units being adapted to be actuated by actuators and arranged around the ink ejection port. Further, the vane units are adapted to be actuated by the vane actuators so as to pressurise the volume around the ink ejection port so as to cause the ejection of ink from the ink ejection port.
  • Advantageously, the vane actuators each comprise two arms, being an expanding, flexible arm, and a rigid arm. The flexible arm can comprise a conductive heater material encased within an expansion material having a high coefficient of thermal expansion. Further, the conductive heater material in the flexible arm is constructed so as to concertina upon expansion of the expansion material. Advantageously, the heater material is of a serpentine form so as to allow substantially unhindered expansion of the expansion material during heating. The rigid arm of the thermal actuator can include the return trace of the heater and the vane. The vane units are arranged in a circumference around the ink ejection port and operate as an iris around the ink ejection port. Further, the vane units can be of a semi-circular form and each ink jet nozzle can comprise four vane units. The expansion material of the thermal actuators can be substantially comprised of polytetra-fluoroethylene and the conductive heater material can comprise substantially copper.
  • The outer surface of the nozzle chamber can include a plurality of etchant holes provided so as to allow a more rapid etching of sacrificial layers during construction.
  • In accordance with a further aspect of the present invention there is provided a thermal actuator comprising a heater element encased within a material having a high coefficient of thermal expansion whereby the actuator operates via means of electrically heating the heater element of the thermal actuator, wherein the heater element has a corrugated structure so as to improve the thermal distribution of heat from the heater element to the actuation material so as to increase the speed of actuation of the thermal actuator. Further the heater element can be of a serpentine or concertina form so as to allow substantially unhindered expansion of the actuation material during heating. The thermal actuator is utilized in an ink jet nozzle for the ejection of ink from a nozzle chamber. Advantageously, both surfaces of the actuator are hydrophilic and the heater material within the actuator can comprise substantially copper. The hydrophilic material can be formed by means of suitable processing a hydrophobic material.
  • In accordance with a further aspect of the current invention, there is provided a thermal actuator comprising a heater element having a low coefficient of thermal expansion surrounded by an actuation material having a high coefficient of thermal expansion wherein the thermal actuator includes a first and second layers of actuation material and a third layer of conductive material, at least a portion of which is utilized as a heating element, wherein a portion of the conductor material has a series of slots or holes so as to allow the actuation material to be integrally joined together so as to reduce the likelihood of delamination of the layers. Advantageously, the portion having a series of slots or holes comprises a stiff structural paddle at one end of the actuator.
  • Further the stiff structural paddle can include a regularly spaced array of holes defined therein.
  • In accordance with a further aspect of the current invention, there is provided an ink jet nozzle comprising the thermal actuator as one wall of an ink chamber, wherein the thermal actuator is attached to a wall of the nozzle chamber, and an ink chamber with an ejection port for the ejection of ink in a wall opposite to the wall formed by the thermal actuator.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle comprising a nozzle chamber having an ink ejection port in one wall of the chamber, an ink supply source interconnected to the nozzle chamber and a thermal actuator activated to eject ink from the nozzle chamber via the ink ejection port, the thermal actuator comprising two layers of actuator material having a high coefficient of thermal expansion, a top layer being substantially non conductive and a bottom layer being conductive, the thermal actuator being activated by means of passing a current through the bottom layer so as to cause it to expand relative to the top layer, which is cooled by the chamber ink. Further, the bottom layer comprises portions being conductive and portions being non-conductive such that a circuit is formed for the heating of the bottom layer through the interaction of the conductive and non-conductive portions. Preferably, the resistive circuit is created having predetermined area of low circuit cross-sectional area so as to produce high levels of heating of the actuators in those areas. Advantageously, the non-conductive portions are formed from the same material as the top layer.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle comprising a nozzle chamber having an ink ejection port in one wall of the chamber, an ink supply source interconnected to the nozzle chamber and a thermal actuator activated to eject ink from the nozzle chamber via the ink ejection port, the thermal actuator being activated by means of passing a current through the bottom layer so as to cause it to expand relative to the top layer. Further, the bottom of the actuator can have a hydrophobic surface and during operation the hydrophobic surface causes an air bubble to form under the thermal actuator. The bottom surface of the actuator can be air vented so as to reduce the actuation energy required to eject ink from the nozzle chamber. Advantageously, the air venting comprises a series of small holes underneath the actuator, the holes being interconnected to an air supply channel for the supply of air to the back of the actuator. Further, the area around the bottom surface of the actuator can be constructed from hydrophobic material. The holes are of a size such that, during operation, any fluid is retained within the nozzle chamber. Preferably, the actuator is attached at one end to the nozzle chamber and the holes are located near the attached end and the actuator is constructed from polytetrafluoroethylene. Further, the actuator can a bottom layer treated in portions so as to form a conductive material.
  • In accordance with a further aspect of the present invention there is provided an ink jet printing device of the type having at least one nozzle connected to an ink supply and having a buckle plate able to be deformed so as to eject ink on demand from the nozzle. The buckle plate can be constructed from a first material having a high coefficient of thermal expansion and from a second electrically resistive material for heating the buckle plate. Further the second material can have a lower coefficient of thermal expansion than the first material and is constructed in a serpentine manner so as to allow the expansion of the length of the heater means substantially in accordance with the expansion of the first material. Preferably the first material comprises substantially polytetrafluoroethylene and the second material comprises substantially copper. Further, the energy of activation of the buckle plate for the ejection of a drop of ink is less than about 20 microjoules.
  • In accordance with a further aspect of the present invention an ink ejection nozzle arrangement is presented comprising an ink chamber having an ink ejection port, a pivotally mounted paddle wheel with a first plurality of radial paddle wheel vanes and a second plurality of fixed paddle chambers each of which has a corresponding one of the pivotally mounted paddle wheel vanes defining a surface of the paddle chamber such that upon rotation of the paddle wheel, ink within the paddle chambers is pressurised resulting in the ejection of ink through the ejection port.
  • Further, the paddle chambers can include a side wall having a radial component relative to the pivotally mounted paddle wheel. Preferably, the ink ejection port is located above the pivot point of the paddle wheel. The radial components of the paddle chamber's side walls are located substantially on the circumference of the pivotally mounted paddle wheel. Advantageously, the rotation of the paddle wheel is controlled by a thermal actuator. The thermal actuator comprises an internal electrically resistive element and an external jacket around the resistive element, made of a material having a high coefficient of thermal expansion relative to the embedded resistive element. Further, the resistive element can be of a substantially serpentine form, and preferably, the outer jacket comprises substantially polytetrafluoroethylene. The thermal actuator can undergo circumferential expansion relative to the pivotally mounted paddle wheel.
  • In accordance with a further aspect of the present invention, a method is provided to eject ink from an ink jet nozzle interconnected to the ink chamber. The method comprises construction of a series of paddle chambers within the ink chamber, each of which has at least one moveable wall connected to a central pivoting portion activated by an activation means. After substantially filling the ink chamber with ink, utilization of the activation means connected to the moveable walls to reduce the volume in the paddle chambers results in an increased ink pressure within the chambers and consequential ejection of ink from the ink jet nozzle.
  • In accordance with a further aspect of the present invention there is provided an actuated paddle for the movement of liquid within a chamber comprising a first surface having a hydrophobic surface, wherein the paddle defines a cavity between the hydrophobic surface and a wall of the chamber so as to be amendable to the collection of gasses within the cavity, and the paddle is actuated to move the hydrophobic surface away from the wall of the chamber. Further the degree of movement of the actuated paddle is insufficient to substantially disperse gasses within the cavity.
  • Preferably the actuated paddle is thermally actuated by means of a first structure having a low coefficient of thermal expansion and a second structure having a substantially larger coefficient of thermal expansion. The structure having a high coefficient of thermal expansion is located closer to the cavity than the structure having a low coefficient of thermal expansion.
  • Advantageously, the actuated paddle includes a further surface adjacent to the liquid and the structure having a low coefficient of thermal expansion is located closest to the further surface. The structure having the low coefficient of thermal expansion is substantially liquid cooled by the liquid, whereas the structure having the high coefficient of thermal expansion is located substantially in the cavity. Further, the structure having a high coefficient of thermal expansion and the first surface is substantially comprised from polytetrafluoroethylene. The actuated paddle is attached to the chamber wall.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle comprising the actuated paddle located within a nozzle chamber, an ink supply interconnected to the nozzle chamber and an ink ejection portal in one wall opposite the actuated paddle for the ejection of ink.
  • In accordance with a further aspect of the present invention, there is provided a method of ejecting ink from the ink jet nozzle comprising the utilizing the activation of the actuated paddle to eject ink from the nozzle chamber, wherein the activation causes the actuated paddle to move towards the wall of the ink jet nozzle chamber comprising the ink ejection portal.
  • In accordance with the a further aspect of the present invention there is provided a thermal actuator comprising a heater element encased within a material having a high coefficient of thermal expansion whereby the actuator operates via means of electrically heating the heater element of the thermal actuator wherein the heater element has a corrugated structure so as to improve the thermal distribution of heat from the heater element to the actuation material so as to increase the speed actuation of the thermal actuator. Further the heater element is of a serpentine or concertina form so as to allow substantially unhindered expansion of the actuation material during heating. The thermal actuator is utilized in an ink jet nozzle for the ejection of ink from a nozzle chamber. Advantageously, one surface of the actuator is hydrophobic and the other surface is hydrophilic and the heater material within the actuator comprises substantially copper. The hydrophilic material is formed by means of processing the hydrophobic material.
  • In accordance with a further aspect of the present invention, there is provided a thermal actuator comprising a heater element having a low coefficient of thermal expansion surrounded by an actuation material having a high coefficient of thermal expansion wherein the thermal actuator includes a first and second layers of actuation material and a third layer of conductive material, at least a portion of which is utilized as a heating element, wherein a portion of the conductor material has a series of slots or holes so as to allow the actuation material to be integrally joined together so as to reduce the likelihood of delamination of the layers. Advantageously, the portion having a series of slots or holes comprises a stiff structural petal at an end of the actuator.
  • Further the stiff structural petal can include a regularly spaced array of holes defined therein. The thermal vent actuator is attached at one end of a substrate and includes an actuation material having a high coefficient of thermal expansion, and further the actuator comprises a stable clamp on top of the actuator at the end attached to the substrate, which acts to decrease the likelihood of separation of the actuation material from the substrate. Advantageously, the thermal vent actuator is utilized for the ejection of ink from a chamber via an ink nozzle. The stable clamp forms part of a grille structure for the filtering of ink flow into the chamber for subsequent ejection. Preferably the substrate is fabricated from a silicon wafer and the clamp is substantially comprised of silicon-nitride and is formed by means of a sacrificial etching process.
  • In accordance with a further aspect of the present invention there is provided an ink jet print nozzle including a nozzle chamber having an ink ejection port for the ejection of ink defmed in one wall of said nozzle chamber; an ink channel supply means for the supply of ink to the nozzle chamber; and an actuator mechanism located in the nozzle chamber and adapted to be activated so as to cause the ejection of ink from the nozzle chamber, the actuator mechanism including a portion located between said nozzle chamber and the ink channel supply means.
  • Preferably the actuator mechanism comprises a substantially planar thermal actuator and includes a serpentine conductive gold heater element layer encased within an expansive layer such that, upon activation, the thermal actuator is caused to bend towards said ink ejection port so as to cause the expulsion of ink from said nozzle chamber. One surface of the planar thermal actuator can include a portion having a hydrophobic properties such that, during operation, an air bubble is formed between said surface and a wall of said nozzle chamber so as to increase the efficiency of operation of said thermal actuator.
  • The nozzle chamber is preferably formed on a silicon wafer and the ink channel supply means is formed through the deep anisotropic back etching of a silicon wafer. The actuator can be made from polytetrafluroethylene which is normally hydrophobic and which is plasma treated through said ink channel supply means to make it hydrophilic.
  • The nozzle chamber can be formed on a CMOS substrate and can include aluminium portions constructed so as to protect said substrate for sacrificial etching of said CMOS substrate.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle arrangement for the ejection of ink from an nozzle chamber including a nozzle chamber interconnected to an ink supply and having an ink ejection port in one wall thereof; an ejection paddle for the ejection of ink from the ink ejection port; a thermal actuator mechanism attached to an ejection paddle for the actuation of the ejection paddle causing the ejection of ink; wherein the thermal actuator comprises materials having a high Young's modulus which produce a bending motion upon heating thereby causing the ejection paddle to eject ink from the ink ejection port.
  • The thermal actuator can be pivoted so as to increase the degree of travel of the ejection paddle upon actuation of the thermal actuator and can be of a horseshoe shaped form and pivoted substantially around a midpoint. The pivot point can be constructed on a wall of the chamber by means of a thinned membrane, there by allowing the thermal actuator operates in the ambient atmosphere. The nozzle chamber is constructed on a silicon wafer and the ink is supplied through the silicon wafer.
  • The thermal actuator can be constructed from a thin conductive section having a high Young's modulus and a substantially thicker non conductive portion. The thin conductive portion can comprise titanium diboride and the thicker portion can comprise glass.
  • The nozzle chamber walls can include a number of small sacrificial etchant holes for utilization in construction of the arrangement, the holes being of sufficiently small diameter so as to prevent the ejection of ink therefrom. The arrangement can be constructed using micro-electro mechanical systems techniques including a sacrificial etch and the ejection paddle is released in the sacrificial etch to be in a prefiring position.
  • In accordance with a further aspect of the present invention, there is provided an inkjet nozzle arrangement for the ejection of ink from a nozzle chamber comprising a nozzle chamber having a slotted sidewall in a first surface and an ink ejection port along a second surface thereof; an ink supply channel interconnected to the nozzle chamber for the supply of ink to the nozzle chamber; a moveable vane located within the nozzle chamber and being moveable so as to cause the ejection of ink from the nozzle chamber; and an actuator located outside the nozzle chamber and interconnected to the moveable vane through the slotted sidewall.
  • The moveable vane, in its quiescent position, can be located substantially adjacent a first end of the slot and the actuator can be actuated to move the moveable vane from the first end of the slot to a second end of the slot. The actuator can comprise a thermal actuator which is actuated by means of an electric current passed through the thermal actuator resulting in resistive heating of the actuator. The thermal actuator can be constructed of a conductive material having a high Young's modulus and include first and second arms, the first arm having a thinned cross-section relative to the second arm, the first arm undergoing resistive heating to thereby cause the first arm to bend resulting in actuation by the thermal actuator. The arms can be attached to a substrate at one end and the second arm can include a thinned portion at one end thereof adjacent the attachment to the substrate.
  • The actuator device preferably operates in an ambient atmosphere and preferably includes portions of the actuator located adjacent the exterior of the slotted side wall which are coated with a hydrophobic material. Further, the arrangement can be formed on a silicon wafer and the ink supply channel is formed through the etching of a channel through the silicon wafer.
  • In accordance with a further aspect of the present invention, there is provided a thermal actuator activated by means of conductive heating of an electrically conductive material, the actuator comprising: a first non-conductive strip of material attached to a substrate at a first end of the strip and adapted to apply a force to a load at a second end of the strip; a second conductive material formed along one side of the strip, the conductive strip including a first wire portion running from substantially the first end to the second end and a second wire strip running from substantially the second end to the first end, the wire strips being joined together at the second end so as to form a circuit, the wire strips being further connected to a controlled power supply at the first end such that activation of the controlled power supply causes heating of the conductive material so as to actuate the thermal actuator thereby applying a force to the load.
  • Preferably, the strip is in the form of a coil and the second conductive material is formed along a radially inner surface of the strip. The first wire and the second wire can be electrically insulated from one another by a layer of the first non-conductive material. Preferably, the second conductive material comprises a material having a high Young's modulus and the first conductive strip is substantially thicker then the second conductive material. The substrate can comprises an electronic circuitry layer of a silicon wafer, the second conductive material can comprise substantially titanium di-boride and the first non-conductive material can comprise substantially glass.
  • The actuator can be interconnected through a slot in a nozzle chamber to a paddle type device, the nozzle chamber being filled with ink and the actuator being activated to eject ink from a port defined in one wall of the nozzle chamber.
  • In accordance with a further aspect of the present invention, there is provided an ink jet printer having a series of ink ejection nozzle chambers each containing: an ink ejection port defmed in one wall of the chamber for the ejection of ink therefrom; a paddle within the chamber, actuated by an actuator for the ejection of ink from the nozzle chamber via the ink ejection port; a slot defined in a second wall thereof for the communication with the paddle of an actuator device; a thermal actuator activated by means of conductive heating of an electrically conductive material, the actuator comprising a first non-conductive strip of material attached to a substrate at a first end of the strip and adapted to apply a force to a load at a second end of the strip; a second conductive material formed along one side of the strip, the conductive strip including a first wire portion running from substantially the first end to the second end and a second wire strip running from substantially the second end to the first end, the wire strips being joined together at the second end so as to form a circuit, the wire strips being further connected to a controlled power supply at the first end such that activation of the controlled power supply causes heating of the conductive material so as to actuate the thermal actuator thereby applying a force to the load.
  • The nozzle chambers can be formed on a silicon wafer and include a series of ink supply channels etched through the wafer for the supply of ink to the nozzle chamber.
  • In accordance with a further aspect of the present invention, there is provided a fluid ejection apparatus including a trough having side walls and an exposed roof, the trough being substantially filled with fluid; a paddle vane located within the trough and offset from one wall when the paddle vane when in a quiescent position; an actuation mechanism attached to the paddle vane such that, upon activation of the actuation mechanism, the paddle vane is caused to move towards the one wall, resulting in an increase in pressure in the fluid between the one wall and the paddle vane, resulting in a consequential ejection of fluid via the exposed roof.
  • Ideally, the present invention can be utilized in an ink jet printing system.
  • The actuation mechanism can be interconnected to the paddle vane via an arm extending over one edge of the exposed roof and the actuation mechanism can comprise a coiled thermal actuator having a first conductive arm and a second substantially non-conductive arm, the conductive arm expanding upon electrical resistive heating to thereby cause the actuation of the thermal actuator. The first conductive arm can comprise substantially titanium diboride and the second non-conductive arm can comprise substantially silicon nitride. The actuation mechanism can operate in the ambient atmosphere.
  • Preferably, the trough is formed within a silicon wafer and the apparatus further comprises an ink supply channel etched through a back surface of the wafer and interconnecting a bottom surface of the trough for the supply of ink to the trough. The interconnection is preferably between the paddle vane and a second wall of the trough.
  • In accordance with a further aspect of the present invention, there is provided an apparatus for ejecting fluids from a nozzle chamber comprising a nozzle chamber having at least two fluid ejection apertures defined in the walls of the chamber; a moveable paddle vane located between the fluid ejection apertures; an actuator mechanism attached to the moveable paddle vane and adapted to move the paddle vane in a first direction so as to cause the ejection of fluid drops out of a first fluid ejection aperture and to further move the paddle vane in a second alternative direction so as to cause the ejection of fluid drops out of a second fluid ejection aperture.
  • The actuator can comprises a thermal actuator having at least two heater elements with a first of the elements being actuated to cause the paddle vane to move in a first direction and a second heater element being actuated to cause the paddle vane to move in a second direction. The heater elements preferably have a high bend efficiency wherein the bend efficiency is defined as: bend efficiency = Young’s Modulus × ( Coefficient of Thermal Expansion ) Density × Specific Heat Capacity
    Figure imgb0001
  • The heater elements can be arranged on opposite sides of a central arm, the central arm having a low thermal conductivity.
  • The paddle vane and the actuator can be joined at a fulcrum pivot point, the fulcrum pivot point comprising a thinned portion of the nozzle chamber wall. The actuator can include one end fixed to a substrate and a second end containing a bifurcated tongue having two leaf portions on each end of the bifurcated tongue, the leaf portions interconnecting to a corresponding side of the paddle with the tongue such that, upon actuation of the actuator, one of the leaf portions pulls on the paddle end.
  • The apparatus can further comprise a fluid supply channel connecting the nozzle chamber with a fluid supply for supplying fluid to the nozzle chamber, the connection being in a wall of the chamber substantially adjacent the quiescent position of the paddle vane. The connection can comprise a slot defined in the wall of the chamber, the slot having similar dimensions to a cross-sectional profile of the paddle vane. The central arm can comprise substantially glass.
  • The apparatus is ideally suited for use in the form of ink jet printer. Each fluid ejection aperture preferably includes a rim defined around an outer surface thereof.
  • Preferably, a multiplicity of apparatuses can be arranged such that the fluid ejection apertures are grouped together spatially into spaced apart rows and fluid is ejected from the fluid ejection apertures of each of the rows in phases. The nozzle chambers can be further grouped into multiple ink colors and with each of the nozzles being supplied with a corresponding ink color.
  • In accordance with a further aspect of the present invention, there is provided a method of ejecting drops of fluid from a nozzle chamber having at least two nozzle apertures defmed in the wall of the nozzle chambers utilizing a moveable paddle vane attached to an actuator mechanism, the method comprising the steps of actuating the actuator to cause the moveable paddle to move in a first direction so as to eject drops from a first of the nozzle apertures; and actuating the actuator causing the moveable paddle to move in a second direction so as to eject drops from a second of the nozzle apertures.
  • In accordance with a further aspect of the present invention, there is provided an apparatus for ejecting fluids from a nozzle chamber including a nozzle chamber having at least two fluid ejection apertures defined in the walls of the chamber; a moveable paddle vane located in a plane adjacent the rim of a first one of the fluid ejection apertures; and an actuator mechanism attached to the moveable paddle vane and adapted to move the paddle vane in a first direction so as to cause the ejection of fluid drops out of the first fluid ejection aperture and to further move the paddle vane in a second alternative direction so as to cause the ejection of fluid drops out of a second fluid ejection aperture.
  • The apparatus can include a baffle located between the first and second fluid ejection apertures such that the paddle vane moving in the first direction causes an increase in pressure of the fluid in the volume adjacent the first aperture and a simultaneous decrease in pressure of the fluid in the volume adjacent the second aperture. Further, the paddle vane moving in the second direction can cause an increase in pressure of the fluid in the volume adjacent the second aperture and a simultaneous decrease in pressure of the fluid in the volume adjacent the first aperture.
  • The paddle vane and the actuator can be interconnected so as to pivot around a wall of the chamber and the apparatus can further comprise a fluid supply channel connecting the nozzle chamber with a fluid supply for supplying fluid to the nozzle chamber, the connection being in a wall of the chamber substantially adjacent the pivot point of the paddle vane.
  • One wall of the nozzle chamber can include at least one smaller aperture interconnecting the nozzle chamber with an ambient atmosphere, the size of the smaller aperture being of such dimensions that, during normal operation of the apparatus, the net flow of fluid through the smaller aperture is zero.
  • The actuator can comprise a thermal actuator having at least two heater elements with a first of the elements being actuated to cause the paddle vane to move in a first direction and a second heater element being actuated to cause the paddle vane to move in a second direction. The heater elements preferably have a high bend efficiency wherein the bend efficiency is defined as: bend efficiency = Young’s Modulus × ( Coefficient of Thermal Expansion ) Density × Specific Heat Capacity
    Figure imgb0002
  • The heater elements can be arranged on opposite sides of a central arm, the central arm having a low thermal conductivity. The central arm can comprise substantially glass. The paddle vane and the actuator are preferably joined at a fulcrum pivot point, the fulcrum pivot point comprising a thinned portion of the nozzle chamber wall. The thermal actuator preferably operates in an ambient atmosphere and the thinned portion of the nozzle chamber wall can include a series of slots at opposing sides so as to allow for the flexing of the wall during actuation of the actuator. Preferably, the external surface adjacent the slots comprises a planar or concave surface so as to reduce wicking. The fluid ejection apertures can include a rim defined around an outer surface thereof.
  • Further, the thermal actuator can include one end attached to a substrate and a second end having a thinned portion, the thinned portion providing for the flexible attachment of the actuator to the moveable paddle vane.
  • A large number of fluid ejection apertures can be grouped together spatially into spaced apart rows and fluid ejected from the fluid ejection apertures of each of the rows in phases. The apparatuses can be ideally utilized for ink jet printing with the nozzle chambers further being grouped into multiple ink colors and with each of the nozzles being supplied with a corresponding ink color.
  • In accordance with a further aspect of the present invention, there is provided a method of ejecting drops of fluid from a nozzle chamber having at least two nozzle apertures defined in the wall of the nozzle chambers utilizing a moveable paddle vane attached to an actuator mechanism, the method comprising the steps of: actuating the actuator to cause the moveable paddle to move in a first direction so as to eject drops from a first of the nozzle apertures; and actuating the actuator to cause the moveable paddle to move in a second direction so as to eject drops from a second of the nozzle apertures.
  • An array of nozzle chambers can be arranged in a pagewidth print head and the moveable paddles of each nozzle chamber are driven in phase for the ejection of ink onto a page.
  • In accordance with a further aspect of the present invention, there is provided an apparatus for ejecting fluids from a nozzle chamber comprising: a nozzle chamber having at least two fluid ejection apertures defined in the walls of the chamber; a moveable paddle vane located in a plane adjacent the rim of a first one of the fluid ejection apertures; and an actuator mechanism attached to the moveable paddle vane and adapted to move the paddle vane in a first direction so as to cause the ejection of fluid drops out of the first fluid ejection aperture and to further move the paddle vane in a second alternative direction so as to cause the ejection of fluid drops out of a second fluid ejection aperture.
  • Preferably, the apparatus further comprises a baffle located between the first and second fluid ejection apertures and wherein the paddle vane moving in the first direction causes an increase in pressure of the fluid in the volume adjacent the first aperture and a simultaneous decrease in pressure of the fluid in the volume adjacent the second aperture.
  • Further, the apparatus preferably includes a deepened etched pit below the second fluid ejection aperture, the baffle and end portion of the moveable paddle vane. Also, the apparatus can include a fluid supply channel connecting the nozzle chamber with a fluid supply for supplying fluid to the nozzle chamber and one surface of the paddle vane includes at least one protrusion, such that, during the movement of the paddle in at least one of the directions, the at least one protrusion mates with a rim of the fluid supply channel so as to restrict the flow of fluid into the fluid supply channel. Also, the moveable paddle vane preferably includes a lip on an end portion adjacent the baffle, the lip substantially abutting the surface of the baffle during operation of the moveable paddle vane.
  • The walls of the chamber can include at least one smaller aperture interconnecting the nozzle chamber with the ambient atmosphere and of such a dimension that, during normal operation of the paddle vane, the surface tension effects across the smaller aperture results in the meniscus across the smaller aperture remaining substantially close to the smaller aperture or within the nozzle chamber. Preferably, at least one smaller aperture(s) is substantially adjacent the first one of the fluid ejection apertures such that, whilst ink is ejected from the second fluid ejection aperture, the meniscus of the first fluid ejection aperture and the at least one smaller aperture are interconnected within the nozzle chamber. Preferably, each aperture can include a ribbed rim around the outer surface thereof.
  • The baffle can include a wall surface having portions spaced at a substantially constant radius from the axis of the second fluid ejection aperture.
  • The actuator can comprise a thermal actuator having at least two heater elements with a first of the elements being actuated to cause the paddle vane to move in a first direction and a second heater element being actuated to cause the paddle vane to move in a second direction. Preferably, the heater elements have a high bend efficiency wherein the bend efficiency is defmed as: bend efficiency = Young’s Modulus × ( Coefficient of Thermal Expansion ) Density × Specific Heat Capacity
    Figure imgb0003
  • A suitable material for the heater elements is a copper nickel alloy. The heater elements are preferably arranged on opposite sides of a central arm, the central arm having a low thermal conductivity and the thermal actuator preferably operates in an ambient atmosphere. The central arm can be made from glass.
  • Preferably, the actuator mechanism is interconnected with the moveable paddle vane through a slot in the wall of the nozzle chamber and includes at least one protruding portion for minimizing any wicking of the fluid along the actuator mechanism. The protrusion can comprise a cusped rim on the actuator mechanism. The slot connects the internal portions of the nozzle chamber with an external ambient atmosphere and preferably the external surface adjacent the slots comprises a planar or concave surface so as to reduce wicking.
  • The present invention is suitable for forming an ink jet print head comprising a multiplicity of apparatuses as previously described with the fluid ejection apertures grouped together spatially into spaced apart rows and fluid is ejected from the fluid ejection apertures of each of the rows in phases. The nozzle chambers are further grouped into multiple ink colors and with each of the nozzles being supplied with a corresponding ink color.
  • In accordance with a further aspect of the present invention, there is provided a method of ejecting drops of fluid from a nozzle chamber having at least two nozzle apertures defined in the wall of the nozzle chambers utilizing a moveable paddle vane attached to an actuator mechanism, the method comprising the steps of: actuating the actuator to cause the moveable paddle to move in a first direction so as to eject drops from a first of the nozzle apertures; and actuating the actuator to cause the moveable paddle to move in a second direction so as to eject drops from a second of the nozzle apertures.
  • The array of nozzle chambers can be arranged in a pagewidth print head and the moveable paddles of each nozzle chamber can be driven in phase.
  • In accordance with a further aspect of the present invention, there is provided an ink jet printing nozzle arrangement including an ink chamber having an ink ejection nozzle in one wall thereof for the ejection of ink from the ink chamber; a moveable paddle vane located within the ink chamber; an actuator means adapted to move the paddle vane so as to cause ink within the ink chamber to be ejected from the ink ejection nozzle; wherein the paddle vane includes a concave surface in the area adjacent the ink ejection nozzle.
  • Preferably, the paddle vane includes a cup shaped surface in the area adjacent the ink ejection nozzle. The nozzle arrangement can be formed utilizing normal micro-electro mechanical construction techniques and the concave surface can be formed as the result of the deposition of a film over a pit.
  • The actuator means can include an actuating portion located externally to the nozzle chamber and operational in an external ambient atmosphere of the arrangement. The ink chamber can further include a slot defined in a wall thereof such that the actuator means communicates with the moveable paddle vane through the slot.
  • The actuator means can comprise a thermal actuator which includes a conductive heater element having a high bend efficiency such that when an electric current is passed through the conductive heater element, the heater element undergoes thermal expansion causing the actuator means to move the paddle towards the ink ejection nozzle.
  • Preferably, the external surfaces of the slot are profiled so as to minimize any wicking of the ink out of the slot. The profile can include a surface having a protruding rim around the slot and the actuator means can be shaped so as to minimize wicking of ink along the actuator means.
  • Further, preferably, the paddle vane includes a slit in a surface thereof to assist in the refill flow of ink into the ink chamber.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle arrangement comprising a nozzle chamber having an fluid ejection nozzle in one surface of the chamber; a paddle vane located within the chamber, the paddle vane being adapted to be actuated by an actuator device for the ejection of fluid out of the chamber via the fluid ejection nozzle; and a thermal actuator device located externally of the nozzle chamber and attached to the paddle vane the thermal actuator device including a plurality of separate spaced apart elongated thermal actuator units.
  • Preferably, the thermal actuator units are interconnected at a first end to a substrate and at a second end to a rigid strut member. The rigid strut member can, in turn, be interconnected to a lever arm having one end attached to the paddle vane. The thermal actuator units can operate upon conductive heating along a conductive trace and the conductive heating includes the generation of a substantial portion of the heat in the area adjacent the first end. The conductive heating trace can include a thinned cross-section adjacent the first end. The heating layers of the thermal actuator units can comprise substantially either a copper nickel alloy or titanium nitride. The paddle can be constructed from a similar conductive material to portions of the thermal actuator units however it is conductively insulated therefrom.
  • Preferably, the thermal actuator units are constructed from multiple layers utilizing a single mask to etch the the multiple layers.
  • The nozzle chamber can include an actuator access port in a second surface of the chamber. The access port can comprise a slot in a corner of the chamber and the actuator is able to move in an arc through the slot. The actuator can include an end portion which mates substantially with a wall of the chamber at substantially right angles to the paddle vane. The paddle vane can include a depressed portion substantially opposite the fluid ejection port.
  • In accordance with a further aspect of the present invention, there is provided a thermal actuator including a series of lever arms attached at one end to a substrate, the thermal actuator being operational as a result of conductive heating of a conductive trace, the conductive trace including a thinned cross-section substantially adjacent the attachment to the substrate.
  • In accordance with a further aspect of the present invention, there is provided an ink jet nozzle arrangement comprising a nozzle chamber having an fluid ejection nozzle in one surface of the chamber; a paddle vane located within the chamber, the paddle vane being adapted to be actuated by an actuator device for the ejection of fluid out of the chamber via the fluid ejection nozzle; and a thermal actuator device located externally of the nozzle chamber and attached to the paddle vane.
  • Preferably, the thermal actuator device includes a lever arm having one end attached to the paddle vane and a second end attached to a substrate. The thermal actuator preferably operates upon conductive heating along a conductive trace and the conductive heating includes the generation of a substantial portion of the heat in the area adjacent the second end. The conductive heating preferably occurs along a thinned cross-section adjacent the second end.
  • Preferably, the thermal actuator includes a first and second layer of a material having similar thermal properties such that upon cooling after deposition of the layers, the two layers act against one another so as to maintain the actuator substantially in a predetermined position. The layers can comprise substantially either a copper nickel alloy or titanium nitride.
  • The paddle can be constructed from a similar conductive material to portions of the thermal actuator however it is conductive insulated therefrom.
  • The thermal actuator can be constructed from multiple layers utilizing a single mask to etch the multiple layers.
  • The nozzle chamber preferably includes an actuator access port in a second surface of the chamber which comprises a slot in a corner of the chamber and the actuator is able to move in an arc through the slot. The actuator can include an end portion which mates substantially with a wall of the chamber at substantially right angles to the paddle vane.
  • The paddle vane can includes a depressed portion substantially opposite the fluid ejection port.
  • In accordance with a further aspect of the present invention, there is provided a thermal actuator device including two layers of material having similar thermal properties such that upon cooling after deposition of the layers, the two layers act against one another so as to maintain the actuator substantially in a predetermined position.
  • In accordance with a further aspect of the present invention, there is provided a thermal actuator including a lever arm attached at one end to a substrate, the thermal actuator being operational as a result of conductive heating of a conductive trace, the conductive trace including a thinned cross-section substantially adjacent the attachment to the substrate.
  • In accordance with a first aspect of the present invention, there is provided an ink jet nozzle arrangement for the ejection from a nozzle chamber out of an ink ejection nozzle, the arrangement comprising: a nozzle chamber for the storage of ink to be ejected; an ink ejection nozzle having a rim formed on one wall of the chamber; and a series of actuator paddles attached to the nozzle rim, and forming a portion of the wall of the nozzle chamber adjacent the rim, the actuator paddles further being actuated in unison so as to eject ink from the nozzle chamber via the ink ejection nozzle.
  • The actutator paddles can include a surface which bends inwards towards the centre of the nozzle chamber upon actuation. The actuator paddles are preferably actuated by means of a thermal actuator device. The thermal actuator device can comprise a conductive resistive heating element encased within a second material having a high coefficient of thermal expansion. The element can be serpentine shaped to allow for substantially unhindered expansion of the second material. The actuator paddles are preferably arranged radially around the nozzle rim.
  • The actuator paddles can form a membrane between the nozzle chamber and an external atmosphere of the arrangement and the paddles bend away from the external atmosphere so as to cause an increase in pressure within the nozzle chamber thereby initiating a consequential ejection of ink from the nozzle chamber. The paddle actuators can bend towards a central axis of the ejection nozzle.
  • The arrangement can be formed on a wafer utilizing micro-electro mechanical techniques and further can comprise an ink supply channel interconnected to the nozzle chamber, the ink supply channel being etched through the wafer. The ink jet nozzle arrangement can include the ink ejection nozzle supported by a series of struts and the actuator paddles are preferably further interconnected to the nozzle rim and the struts further can include a conductive power rail for supplying power to the actuator paddles.
  • The arrangement can be formed adjacent to neighbouring arrangements so as to form a pagewidth print head.
  • In accordance with a first aspect of the present invention, there is provided an ink jet nozzle arrangement for the ejection from a nozzle chamber out of an ink ejection nozzle, the arrangement comprising: a nozzle chamber for the storage of ink to be ejected; an ink ejection nozzle having a rim formed on one wall of the chamber; and a series of actuator paddles attached to the nozzle rim, and forming a portion of the wall of the nozzle chamber adjacent the rim, the actuator paddles further being actuated in unison so as to eject ink from the nozzle chamber via the ink ejection nozzle.
  • The actutator paddles can include a surface which bends inwards towards the centre of the nozzle chamber upon actuation. The actuator paddles are preferably actuated by means of a thermal actuator device. The thermal actuator device can comprise a conductive resistive heating element encased within a second material having a high coefficient of thermal expansion. The element can be serpentine shaped to allow for substantially unhindered expansion of the second material. The actuator paddles are preferably arranged radially around the nozzle rim.
  • The actuator paddles can form a membrane between the nozzle chamber and an external atmosphere of the arrangement and the paddles bend away from the external atmosphere so as to cause an increase in pressure within the nozzle chamber thereby initiating a consequential ejection of ink from the nozzle chamber. The paddle actuators can bend towards a central axis of the ejection nozzle.
  • The arrangement can be formed on a wafer utilizing micro-electro mechanical techniques and further can comprise an ink supply channel interconnected to the nozzle chamber, the ink supply channel being etched through the wafer. The ink jet nozzle arrangement can include the ink ejection nozzle