Direct firing thermal bend actuator ink jet printing mechanism

• US 6,239,821 B1
• Filed: 07/10/1998
• Issued: 05/29/2001
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): Do, An H.
• Application Number:
  US09/112,780
• Time in Patent Office: 1,054 Days
• Field of Search: 347/54, 347/48, 347/84, 347/85, 347/20, 347/44
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

This patent describes an ink jet printer including a thermal actuator including a heater element encased within a material having a high coefficient of thermal expansion whereby the actuator operates by electrical heating the heater. The heater element has a corrugated structure so as to improve the thermal transfer to the actuation material so as to thereby increase the speed of actuation of the thermal actuator. The heater element is also of a serpentine or concertinaed form so as to allow substantially unhindered expansion of the actuation material. The thermal actuator can include layers sandwiched together where 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.

Claims

1. A thermal actuator which comprises a heater element encased within a material having a high coefficient of thermal expansion, said actuator operates by means of electrical heating by said heater element of said thermal actuator wherein said heater element has a corrugated structure so as to improve a thermal distribution of heat from said heater element to the material, the heater element being positioned within the material, closer to one of a pair of opposed surfaces of the material than the other opposed surface, so that expansion of the material at the heater element, when the heater element is energized, results in movement of the actuator.

2. A thermal actuator as claimed in claim 1 wherein the heater element is also of a serpentine or concertina form to allow substantially unhindered expansion of the actuation material during heating.

3. A thermal actuator as claimed in claim 1 wherein the actuator comprises part of an inkjet nozzle arrangement for ejecting ink from a nozzle chamber.

4. A thermal actuator as claimed in claim 1 wherein surfaces of the actuator are hydrophilic.

5. A thermal actuator as claimed in claim 1 wherein the heater element is substantially copper.

6. A thermal actuator which comprises a heater element having a low coefficient of thermal expansion surrounded by an actuation material having a high coefficient of thermal expansion wherein said thermal actuator includes first and second layers of the actuation material and a third layer of conductive material positioned between the first and second layers of the actuation material, at least a portion of the conductive material being utilized as a heating element and wherein a remaining portion of the conductive material has a series of slots or holes so as to allow the first and second layers of the actuation material to be integrally joined together to reduce a likelihood of delamination of the layers, with one of the layers being thinner than the other layer so that, when the heater element is energized, an extent of thermal expansion of the thinner layer is greater than that of the thicker layer, resulting in movement of the actuator.

7. A thermal actuator as claimed in claim 6 wherein the remaining portion of the heater element having the series of slots or holes serves to stiffen the actuator.

8. A thermal actuator as claimed in claim 7 wherein the remaining portion of the heater element includes a regularly spaced array of holes defined therein.

9. A nozzle arrangement for an ink jet printer, the nozzle arrangement comprising

ink chamber walls, which define an ink chamber;

an ink ejection port defined in one of the ink chamber walls; and

a thermal actuator which comprises a heater element encased within a material having a high coefficient of thermal expansion, whereby said actuator operates by means of electrical heating by said heater element of said thermal actuator wherein said heater element has a corrugated structure so as to improve a thermal distribution of heat from said heater element to said actuation material, the heater element being positioned within the material, closer to one of a pair of opposed surfaces of the material than the other opposed surface, so that expansion of the material at the heater element, when the heater element is energized, results in movement of the actuator.

10. A nozzle arrangement for an inkjet printer, the nozzle arrangement comprising

ink chamber walls, which define an ink chamber;

an ink ejection port defined in one of the ink chamber walls; and

a thermal actuator which comprises a heater element having a low coefficient of thermal expansion surrounded by an actuation material having a high coefficient of thermal expansion wherein said thermal actuator includes first and second layers of the actuation material and a third layer of conductive material positioned between the first and second layers of the actuation material, at least a portion of the conductive material being utilized as a heating element and wherein a remaining portion of the conductive material has a series of slots or holes so as to allow the first and second layers of the actuation material to be integrally joined together to reduce a likelihood of delamination of the layers, with one of the layers being thinner than the other layer so that, when the heater element is energized, an extent of thermal expansion of the thinner layer is greater than that of the thicker layer, resulting in movement of the actuator.