PRINTHEAD INCLUDING A LOOPED HEATER ELEMENT

• US 20080049072A1
• Filed: 10/28/2007
• Published: 02/28/2008
• Est. Priority Date: 07/15/1997
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Granted Patent: US 7,717,543 B2
• Time in Patent Office: Days
• US Class Current: 347/61
• CPC Class Codes: B41J 2/1412 Shape
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1601 Production of bubble jet print heads B41J2/1606, B41J2/162 take precedence
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 : Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14435 : Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14475 : characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 : by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 : multi-dimensional coding
• CPC Class Codes: G06K 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 1/2154 : the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 2101/00 : Still video cameras
• 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

An ink jet printhead comprising: a plurality of nozzles; a bubble forming chamber corresponding to each of the nozzles respectively, the bubble forming chambers adapted to contain a bubble forming liquid; and at least one looped heater element disposed in each of the bubble forming chambers respectively, the heater elements configured for thermal contact with the bubble forming liquid; wherein heating of the looped heater element to a temperature above the boiling point of the bubble forming liquid forms a gas bubble that causes the ejection of a drop of an ejectable liquid through the nozzle corresponding to that heater element.

Claims

1. An ink jet printhead comprising:

a plurality of nozzles;

a bubble forming chamber corresponding to each of the nozzles respectively, the bubble forming chambers adapted to contain a bubble forming liquid; and

at least one looped heater element disposed in each of the bubble forming chambers respectively, the heater elements configured for thermal contact with the bubble forming liquid;

wherein heating of the looped heater element to a temperature above the boiling point of the bubble forming liquid forms a gas bubble that causes the ejection of a drop of an ejectable liquid through the nozzle corresponding to that heater element.

2. The ink jet printhead according to claim 1, wherein the bubble forming chamber has a circular cross section.

3. The ink jet printhead according to claim 1, wherein each looped heater element includes a plurality of single omega profiled sections which extend at least partially along an axis of the respective bubble forming chamber.

4. The ink jet printhead according to claim 1, wherein each looped heater element includes a plurality of double omega profiled sections which extend at least partially along an axis of the respective bubble forming chamber.

5. The ink jet printhead according to claim 1, wherein each bubble forming chamber is cylindrical.

6. The ink jet printhead according to claim 1, wherein the bubble forming chamber is barrel-shaped.

7. The ink jet printhead according to claim 1, wherein the bubble forming chamber has a truncated coned profile.

8. The ink jet printhead according to claim 1, wherein the ink jet printhead includes:

an underlying substrate;

a unitary amorphous ceramic structure having a nozzle plate with a plurality of nozzles formed therein; and

an array of sidewalls extending from one side of the nozzle plate to the underlying substrate, wherein the underlying substrate, the nozzle plate and the array of sidewalls define the bubble forming chambers.

9. The ink jet printhead according to claim 1, wherein the ejectable liquid is the same as the bubble forming liquid.

10. The ink printhead according to claim 1, wherein the printhead is a pagewidth printhead,

11. The ink jet printhead according to claim 1, wherein the looped heater elements are actuated by one or more drive circuits which are located partially on a side of one of the bubble forming chambers.

12. The ink jet printhead according to claim 11, wherein one or more drive circuits conduct a thermal pulse in order to form the gas bubble.

13. The ink jet prinhead according to claim 12, wherein the thermal pulse occurs for a period of one millisecond.

14. The ink jet printhead according to claim 1, wherein the looped heater elements have a serpentine profile.

15. The ink jet printhead according to claim 1, wherein the bubble forming chamber is in fluid communication with an inlet passage which supplies the bubble forming liquid, wherein when the drop of the ejectable liquid is being ejected, a portion of the bubble forming contained within the bubble forming chamber is withdrawn through the inlet passage.

16. The ink jet printhead according to claim 1, wherein each looped heater element includes a bubble nucleation section which includes a smaller cross-section than a remainder of the respective looped heater element.

17. The ink jet printhead according to claim 16, wherein each bubble nucleation section has a greater thermal resistance than the remainder of the respective looped heater element.

18. The ink jet printhead according to claim 17, wherein each bubble nucleation section heats to a temperature above the boiling point for the bubble forming liquid prior to the remainder of the respective looped heater element.

19. The ink jet printhead according to claim 16, wherein each looped heater element undergoes thermal expansion, wherein the respective bubble nucleation section rotates relative to the looped heater element.