Quantcast

Thermal ink jet printhead with symmetric bubble formation

Imported: 24 Feb '17 | Published: 06 Jan '04

Kia Silverbrook, Angus John North, Gregory John McAvoy

USPTO - Utility Patents

Abstract

There is disclosed an ink jet printhead which comprises a plurality of nozzles and one or more heater elements corresponding to each nozzle. Each heater element is configured to heat a bubble forming liquid in the printhead to a temperature above its boiling point to form a gas bubble therein. The generation of the bubble causes the ejection of a drop of an ejectable liquid (such as ink) through the respective corresponding nozzle, to effect printing. Each heater element has two opposite sides and is configured such that the gas bubble formed by that heater element is formed at both of these sides.

Description

DETAILED DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying representations. The drawings are described as follows.

FIG. 1 is a schematic cross-sectional view through an ink chamber of a unit cell of a printhead according to an embodiment of the invention, at a particular stage of operation.

FIG. 2 is a schematic cross-sectional view through the ink chamber FIG. 1, at another stage of operation.

FIG. 3 is a schematic cross-sectional view through the ink chamber FIG. 1, at yet another stage of operation.

FIG. 4 is a schematic cross-sectional view through the ink chamber FIG. 1, at yet a further stage of operation.

FIG. 5 is a diagrammatic cross-sectional view through a unit cell of a printhead in accordance with the an embodiment of the invention showing the collapse of a vapor bubble.

FIGS. 6,

8,

10,

11,

13,

14,

16,

18,

19,

21,

23,

24,

26,

28 and

30 are schematic perspective views (FIG. 30 being partly cut away) of a unit cell of a printhead in accordance with an embodiment of the invention, at various successive stages in the production process of the printhead.

FIGS. 7,

9,

12,

15,

17,

20,

22,

25,

27,

29 and

31 are each schematic plan views of a mask suitable for use in performing the production stage for the printhead, as represented in the respective immediately preceding figures.

FIG. 32 is a further schematic perspective view of the unit cell of FIG. 30 shown with the nozzle plate omitted.

FIG. 33 is a schematic perspective view, partly cut away, of a unit cell of a printhead according to the invention having another particular embodiment of heater element.

FIG. 34 is a schematic plan view of a mask suitable for use in performing the production stage for the printhead of FIG. 33 for forming the heater element thereof.

FIG. 35 is a schematic perspective view, partly cut away, of a unit cell of a printhead according to the invention having a further particular embodiment of heater element.

FIG. 36 is a schematic plan view of a mask suitable for use in performing the production stage for the printhead of FIG. 35 for forming the heater element thereof.

FIG. 37 is a further schematic perspective view of the unit cell of FIG. 35 shown with the nozzle plate omitted.

FIG. 38 is a schematic perspective view, partly cut away, of a unit cell of a printhead according to the invention having a further particular embodiment of heater element.

FIG. 39 is a schematic plan view of a mask suitable for use in performing the production stage for the printhead of FIG. 38 for forming the heater element thereof.

FIG. 40 is a further schematic perspective view of the unit cell of FIG. 38 shown with the nozzle plate omitted.

FIG. 41 is a schematic section through a nozzle chamber of a printhead according to an embodiment of the invention showing a suspended beam heater element immersed in a bubble forming liquid.

FIG. 42 is schematic section through a nozzle chamber of a printhead according to an embodiment of the invention showing a suspended beam heater element suspended at the top of a body of a bubble forming liquid.

FIG. 43 is a diagrammatic plan view of a unit cell of a printhead according to an embodiment of the invention showing a nozzle.

FIG. 44 is a diagrammatic plan view of a plurality of unit cells of a printhead according to an embodiment of the invention showing a plurality of nozzles.

FIG. 45 is a diagrammatic section through a nozzle chamber not in accordance with the invention showing a heater element embedded in a substrate.

FIG. 46 is a diagrammatic section through a nozzle chamber in accordance with an embodiment of the invention showing a heater element in the form of a suspended beam.

FIG. 47 is a diagrammatic section through a nozzle chamber of a prior art printhead showing a heater element embedded in a substrate.

FIG. 48 is a diagrammatic section through a nozzle chamber in accordance with an embodiment of the invention showing a heater element defining a gap between parts of the element.

FIG. 49 is a diagrammatic section through a nozzle chamber not in accordance with the invention, showing a thick nozzle plate.

FIG. 50 is a diagrammatic section through a nozzle chamber in accordance with an embodiment of the invention showing a thin nozzle plate.

FIG. 51 is a diagrammatic section through a nozzle chamber in accordance with an embodiment of the invention showing two heater elements.

FIG. 52 is a diagrammatic section through a nozzle chamber of a prior art printhead showing two heater elements.

FIG. 53 is a diagrammatic section through a pair of adjacent unit cells of a printhead according to an embodiment of the invention, showing two different nozzles after drops having different volumes have been ejected therethrough.

FIGS. 54 and 55 are diagrammatic sections through a heater element of a prior art printhead.

FIG. 56 is a diagrammatic section through a conformally coated heater element according to an embodiment of the invention.

FIG. 57 is a diagrammatic elevational view of a heater element, connected to electrodes, of a printhead according to an embodiment of the invention.

FIG. 58 is a schematic exploded perspective view of a printhead module of a printhead according to an embodiment of the invention.

FIG. 59 is a schematic perspective view the printhead module of FIG. 58 shown unexploded.

FIG. 60 is a schematic side view, shown partly in section, of the printhead module of FIG.

58.

FIG. 61 is a schematic plan view of the printhead module of FIG.

58.

FIG. 62 is a schematic exploded perspective view of a printhead according to an embodiment of the invention.

FIG. 63 is a schematic further perspective view of the printhead of FIG. 62 shown unexploded.

FIG. 64 is a schematic front view of the printhead of FIG.

62.

FIG. 65 is a schematic rear view of the printhead of FIG.

62.

FIG. 66 is a schematic bottom view of the printhead of FIG.

62.

FIG. 67 is a schematic plan view of the printhead of FIG.

62.

FIG. 68 is a schematic perspective view of the printhead as shown in FIG. 62, but shown unexploded.

FIG. 69 is a schematic longitudinal section through the printhead of FIG.

62.

FIG. 70 is a block diagram of a printer system according to an embodiment of the invention.

Claims

1. An ink jet printhead comprising:

2. The printhead of claim 1 being configured to support the bubble forming liquid in thermal contact with each said heater element, and to support the ejectable liquid adjacent each nozzle.

3. The printhead of claim 1 wherein the bubble forming liquid and the ejectable liquid are of a common body of liquid.

4. The printhead of claim 1 being configured to print on a page and to be a page-width printhead.

5. The printhead of claim 1 wherein each heater element is in the form of a suspended beam configured such that a gas bubble formed by that heater element is formed so as to surround that heater element.

6. The printhead of claim 1 wherein each heater element is in the form of a suspended beam, arranged for being suspended over at least a portion of the bubble forming liquid so as to be in thermal contact therewith.

7. The printhead of claim 1 wherein each heater element is configured such that an actuation energy of less than 500 nanojoules (nJ) is required to be applied to that heater element to heat that heater element sufficiently to form a said bubble in the bubble forming liquid thereby to cause the ejection of a said drop.

8. The printhead of claim 1 configured to receive a supply of the ejectable liquid at an ambient temperature, wherein each heater element is configured such that the energy required to be applied thereto to heat said part to cause the ejection of a said drop is less than the energy required to heat a volume of said ejectable liquid equal to the volume of the said drop, from a temperature equal to said ambient temperature to said boiling point.

9. The printhead of claim 1 comprising a substrate having a substrate surface, wherein each nozzle has a nozzle aperture opening through the substrate surface, and wherein the areal density of the nozzles relative to the substrate surface exceeds 10,000 nozzles per square cm of substrate surface.

10. The printhead of claim 1 wherein the bubble which each heater element is configured to form is collapsible and has a point of collapse, and wherein each heater element is configured such that the point of collapse of a bubble formed thereby is spaced from that heater element.

11. The printhead of claim 1 comprising a structure that is formed by chemical vapor deposition (CVD), the nozzles being incorporated on the structure.

12. The printhead of claim 1 comprising a structure that is less than 10 microns thick, the nozzles being incorporated on the structure.

13. The printhead of claim 1 comprising a plurality of nozzle chambers, each corresponding to a respective nozzle, and a plurality of said heater elements being disposed within each chamber, the heater elements within each chamber being formed on different respective layers to one another.

14. The printhead of claim 1 wherein each heater element is formed of solid material more than 90% of which, by atomic proportion, is constituted by at least one periodic element having an atomic number below 50.

15. The printhead of claim 1 wherein each heater element includes solid material and is configured for a mass of less than 10 nanograms of the solid material of that heater element to be heated to a temperature above said boiling point thereby to heat said part of the bubble forming liquid to a temperature above said boiling point to cause the ejection of a said drop.

16. The printhead of claim 1 wherein each heater element is substantially covered by a conformal protective coating, the coating of each heater element having been applied substantially to all sides of the heater element simultaneously such that the coating is seamless.

17. A printer system incorporating a printhead, the printhead comprising:

18. The system of claim 17 being configured to support the bubble forming liquid in thermal contact with each said heater element, and to support the ejectable liquid adjacent each nozzle.

19. The system of claim 17 wherein the bubble forming liquid and the ejectable liquid are of a common body of liquid.

20. The system of claim 17 being configured to print on a page and to be a page-width printhead.

21. The system of claim 17 wherein each heater element is in the form of a suspended beam configured such that a gas bubble formed by that heater element is formed so as to surround that heater element.

22. The system of claim 17 wherein each heater element is in the form of a suspended beam, arranged for being suspended over at least a portion of the bubble forming liquid so as to be in thermal contact therewith.

23. The system of claim 17 wherein each heater element is configured such that an actuation energy of less than 500 nanojoules (nJ) is required to be applied to that heater element to heat that heater element sufficiently to form a said bubble in the bubble forming liquid thereby to cause the ejection of a said drop.

24. The system of claim 17, wherein the printhead is configured to receive a supply of the ejectable liquid at an ambient temperature, and wherein each heater element is configured such that the energy required to be applied thereto to heat said part to cause the ejection of a said drop is less than the energy required to heat a volume of said ejectable liquid equal to the volume of the said drop, from a temperature equal to said ambient temperature to said boiling point.

25. The system of claim 17 comprising a substrate having a substrate surface, wherein each nozzle has a nozzle aperture opening through the substrate surface, and wherein the areal density of the nozzles relative to the substrate surface exceeds 10,000 nozzles per square cm of substrate surface.

26. The system of claim 17 wherein the bubble which each heater element is configured to form is collapsible and has a point of collapse, and wherein each heater element is configured such that the point of collapse of a bubble formed thereby is spaced from that heater element.

27. The system of claim 17 comprising a structure that is formed by chemical vapor deposition (CVD), the nozzles being incorporated on the structure.

28. The system of claim 17 comprising a structure that is less than 10 microns thick, the nozzles being incorporated on the structure.

29. The system of claim 17 comprising a plurality of nozzle chambers, each corresponding to a respective nozzle, and a plurality of said heater elements being disposed within each chamber, the heater elements within each chamber being formed on different respective layers to one another.

30. The system of claim 17 wherein each heater element is formed of solid material more than 90% of which, by atomic proportion, is constituted by at least one periodic element having an atomic number below 50.

31. The system of claim 17 wherein each heater element includes solid material and is configured for a mass of less than 10 nanograms of the solid material of that heater element to be heated to a temperature above said boiling point thereby to heat said part of the bubble forming liquid to a temperature above said boiling point to cause the ejection of a said drop.

32. The system of claim 17 wherein each heater element is substantially covered by a conformal protective coating, the coating of each heater element having been applied substantially to all sides of the heater element simultaneously such that the coating is seamless.

33. A method of ejecting a drop of an ejectable liquid from a printhead, the printhead comprising a plurality of nozzles and at least one respective heater element corresponding to each nozzle wherein each heater element has two opposite sides, the method comprising the steps of:

34. The method of claim 33 comprising, before said step of heating, the steps of:

35. The method of claim 33 wherein the bubble forming liquid and the ejectable liquid are of a common body of liquid.

36. The method of claim 33 wherein each heater element is in the form of a suspended beams, the step of generating a gas bubble comprising generating the gas bubble so that it surrounds the heated heater element.

37. The method of claim 33 wherein each heater element is in the form of a suspended beam, the method further comprising, prior to the step of heating at least one heater element, the step of disposing the bubble forming liquid such that the heater elements are positioned above, and in thermal contact with, at least a portion of the bubble forming liquid.

38. The method of claim 33 wherein said step of heating at least one heater element is effected by applying an actuation energy of less than 500 nJ to each such heater element.

39. The method of claim 33, comprising, prior to the step of heating at least one heater element, the step of receiving a supply of the ejectable liquid, at an ambient temperature, to the printhead, wherein the step of heating is effected by applying heat energy to each such heater element, wherein said applied heat energy is less than the energy required to heat a volume of said ejectable liquid equal to the volume of said drop, from a temperature equal to said ambient temperature to said boiling point.

40. The method of claim 33 further comprising the step of providing the printhead wherein the printhead includes a substrate on which said nozzles are discposed, the substrate having a substrate surface, and the areal density of the nozzles relative to the substrate surface exceeding 10,000 nozzles per square cm of substrate surface.

41. The method of claim 33 wherein, in the step of generating a gas bubble, the generated bubble is collapsible and has a point of collapse, and is generated such that the point of collapse is spaced from the at least one heated heater element.

42. The method of claim 33 further comprising the step of providing the printhead, including forming a structure by chemical vapor deposition (CVD), the structure incorporating the nozzles thereon.

43. The method of claim 33 further comprising the step of providing the printhead, wherein the printhead has a structure which is less than 10 microns thick and which incorporates said nozzles thereon.

44. The method of claim 33 wherein the printhead has a plurality of nozzle chambers, each chamber corresponding to a respective nozzle, the method further comprising the step of providing the printhead including forming a plurality of said heater elements in each chamber, such that the heater elements in each chamber are formed on different respective layers to one another.

45. The method of claim 33 further comprising the step of providing the printhead, wherein each heater element is formed of solid material more than 90% of which, by atomic proportion, is constituted by at least one periodic element having an atomic number below 50.

46. The method of claim 33 wherein each heater element includes solid material, and wherein the step of heating at least one heater element comprises heating a mass of less than 10 nanograms of the solid material of each such heater element to a temperature above said boiling point.

47. The method of claim 33 further comprising the step of providing the printhead, including applying to each heater element, substantially to all sides thereof simultaneously, a conformal protective coating such that the coating is seamless.