Thermal inkjet printer having enhanced heat removal capability and method of assembling the printer

• US 6,607,259 B2
• Filed: 10/11/2001
• Issued: 08/19/2003
• Est. Priority Date: 10/11/2001
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Butler, Blair, Mott, James A
• Primary Examiner(s): Gordon, Raquel Yvette
• Assistant Examiner(s): Stewart, Jr., Charles W.
• Application Number:
  US09/975,781
• Publication Number:
  US 20030071865A1
• Time in Patent Office: 677 Days
• Field of Search: 347/18, 347/19, 347/85, 347/86, 347/87, 347/17, 347/23, 347/63, 347/6, 347/7, 219/544, 392/451
• US Class Current: 347/18
• CPC Class Codes: B41J 2/1408 Structure dealing with thermal variations, e.g. cooling device, thermal coefficients of materials
• CPC Class Codes: B41J 2002/14403 including a filter

Abstract

A thermal ink jet printer having enhanced heat removal capability and method of assembling the printer. The thermal inkjet printer includes a thermal inkjet print bead adapted to hold an ink body therein. A heating element is adapted to be in fluid communication with the ink body for generating heat to heat the ink body. A vapor bubble forms in the ink body to eject an ink drop when the heating element causes the ink body to reach a predetermined temperature. Presence of the vapor bubble forces on ink drop out the printer to form an image on a recording medium. A conductive heat removal structure is in thermal communication with the heating element and is also in fluid communication with the ink body. Heat generated by the heating element is transferred from the heating element and into the heat removal structure. The heat removal structure then surrenders the heat to the ink body, which functions as an “infinite” heat sink. In this manner, the heat removal structure provides enhanced heat removal of heat generated by the heating element.

Claims

1. A thermal inkjet printer having enhanced heat removal capability, comprising:

a. a thermal inkjet print head adapted to hold an ink body, said print head including;

i. a heating element adapted to be in fluid communication with the ink body;

ii. a heat removal structure in thermal communication with said heating element for transferring heat from said heating element to the ink body; and

b. a controller coupled to said heating element.

2. The printer of claim 1, wherein said heat removal structure is porous.

3. The printer of claim 1, wherein said heat removal structure defines a cooling chamber therein for receiving a coolant.

4. The printer of claim 3, wherein said heat removal structure forms a protuberance filled with the coolant and in thermal communication with the ink chamber.

5. The printer of claim 1, wherein said heat removal structure comprises a fin.

6. The printer of claim 1, wherein said heat removal structure comprises an agitator.

7. The printer of claim 1, wherein said heat removal structure defines a coolant flow channel therein.

8. The printer of claim 7, wherein said heat removal structure comprises a pump coupled to the flow channel.

9. The printer of claim 7, wherein said heat removal structure comprises a heat conductor bridge interconnecting said heating element and said flow channel.

10. A thermal inkjet printer having enhanced heat removal capability, comprising:

a. a thermal inkjet print head adapted to hold an ink body therein, said print head including;

i. an resistive heating element adapted to be in fluid communication with the ink body for generating heat to heat the ink body, so that a vapor bubble forms in the ink body;

ii. a heat removal structure in thermal communication with said heating element and in fluid communication with the ink body for transferring the heat from said heating element to the ink body; and

b. a controller coupled to said heating element for controllably supplying a plurality of electrical pulses to said heating element for electrically energizing said heating element.

11. The printer of claim 10, wherein said heat removal structure comprises:

a. a thermally conductive support member coupled to said heating element for supporting said heating element and for conducting the heat from said heating element and through said support member; and

b. a thermally conductive heat sink coupled to said support member and in fluid communication with the ink body for transferring the heat from the support member and to the ink body.

12. The printer of claim 11, wherein said heat sink is porous for filtering the ink body.

13. The printer of claim 11, wherein said heat sink comprises an enclosure defining a cooling chamber for enclosing a thermally conductive coolant therein.

14. The printer of claim 13, wherein said enclosure forms a protuberance projecting into the ink body for increasing heat transfer surface area of said enclosure, the protuberance forming a cavity therein in thermal communication with the chamber, the cavity being adapted to receive the coolant.

15. The printer of claim 10, wherein said heat removal structure comprises a cooling fin integrally formed therewith for increasing heat transfer surface area of said heat removal structure.

16. The printer of claim 10, wherein said heat removal structure comprises an agitator in fluid communication with the ink body for agitating the ink body, so that the heat disperses throughout the ink body.

17. The printer of claim 16, wherein said agitator comprises a rotatable propeller.

18. The printer of claim 16, wherein said agitator comprises an oscillatable membrane.

19. The printer of claim 10, wherein said heat removal structure defines a coolant flow channel therein for passage of a coolant therealong.

20. The printer of claim 19, wherein said heat removal structure comprises a pump coupled to the flow channel for pumping the coolant along the flow channel.

21. The printer of claim 20, wherein said pump comprises a piezoelectric member capable of flexing in response to a plurality of timed electrical pulses transmitted to said piezoelectric member.

22. The printer of claim 20, wherein said pump comprises a thermal resistor unit capable of heating the coolant in response to a plurality of timed electrical pulses transmitted to said thermal resistor unit.

23. The printer of claim 19, wherein said heat removal structure comprises a heat conductor bridge interconnecting said heating element and the flow channel for transferring heat from said heating element and to the flow channel.

24. A thermal inkjet print head having enhanced heat removal capability, comprising:

a. an ink jet cartridge shell adapted to hold an ink body;

b. a heating element disposed in said ink cartridge shell and adapted to be in fluid communication with the ink body, and

c. a heat removal structure in thermal communication with said heating element for transferring heat from said heating element and to the ink body.

25. The print head of claim 24, wherein said heat removal structure is porous.

26. The print head of claim 24, wherein said heat removal structure defines a cooling chamber therein for receiving a coolant.

27. The print head of claim 26, wherein said heat removal structure forms a protuberance filled with the coolant and in thermal communication with the chamber.

28. The print head of claim 24, wherein said heat removal structure comprises a fin.

29. The print head of claim 24, wherein said heat removal structure comprises an agitator.

30. The print head of claim 24, wherein said heat removal structure defines a coolant flow channel therein.

31. The print head of claim 30, wherein said heat removal structure comprises a pump coupled to the flow channel.

32. The print head of claim 30, wherein said heat removal structure comprises a heat conductor bridge interconnecting said heating element and the flow channel.

33. A method of assembling a thermal inkjet printer having enhanced heat removal capability, comprising the steps of:

a. providing a heating element adapted to be in fluid communication with an ink body;

b. arranging a heat removal structure so as to be in thermal communication with the heating element for transferring heat from the heating element to the ink body; and

c. coupling a controller to the heating element.

34. The method of claim 33, wherein the step of arranging the heat removal structure comprises the step of arranging a heat removal structure that is porous.

35. The method of claim 33, further comprising the step of forming a cooling chamber in the heat removal structure for receiving a coolant.

36. The method of claim 35, further comprising the step of forming a protuberance outwardly projecting from the heat removal structure and having a hollow interior in thermal communication with the chamber, the protuberance adapted to be filled with the coolant.

37. The method of claim 33, further comprising the step of forming a fin on a surface of the heat removal structure.

38. The method of claim 33, further comprising the step of coupling an agitator to the heat removal structure.

39. The method of claim 33, further comprising the step of forming a coolant flow channel in the heat removal structure.

40. The method of claim 39, further comprising the step of coupling a pump to the flow channel.

41. The method of claim 39, further comprising the step of interconnecting a heat conductor bridge to the heating element and the flow channel.

42. A method of assembling a thermal inkjet print head having enhanced heat removal capability, comprising the steps of:

a. providing an ink cartridge shell adapted to hold an ink body;

b. disposing a heating element in the ink cartridge shell, the heating element adapted to be in fluid communication with the ink body; and

c. arranging a heat removal structure in thermal communication with the heating element for transferring heat from the heating element to the ink body.

43. The method of claim 42, wherein the heat removal structure is porous.

44. The method of claim 42, further comprising the step of forming a cooling chamber in the heat removal structure for receiving a coolant.

45. The method of claim 44, further comprising the step of forming a protuberance outwardly projecting from the heat removal structure and having a hollow interior in thermal communication with the chamber, the protuberance adapted to be filled with the coolant.

46. The method of claim 42, further comprising the step of forming a fin on a surface of the heat removal structure.

47. The method of claim 42, further comprising the step of coupling an agitator to the heat removal structure.

48. The method of claim 42, further comprising the step of forming a coolant flow channel in the heat removal structure.

49. The method of claim 48, further comprising the step of coupling a pump to the flow channel.

50. The method of claim 48, further comprising the step of interconnecting a heat conductor bridge to the heating element and the flow channel.