Apparatus and method for drying ink deposited by ink jet printing

• US 5,631,685 A
• Filed: 11/30/1993
• Issued: 05/20/1997
• Est. Priority Date: 11/30/1993
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sirkis, Murray D., Gooray, Arthur M., Peter, Kenneth C.
• Primary Examiner(s): Hartary, Joseph W.
• Application Number:
  US08/159,908
• Time in Patent Office: 1,267 Days
• Field of Search: 347/102, 347/42, 219/700, 219/701, 219/692, 34/264, 34/259, 101/488, 101/424.1, 355/287
• US Class Current: 347/102
• CPC Class Codes: B41J 11/00216 using infrared [IR] radiation or microwaves
• CPC Class Codes: H05B 2206/046 Microwave drying of wood, ink, food, ceramic, sintering of ceramic, clothes, hair
• CPC Class Codes: H05B 6/70 Feed lines
• CPC Class Codes: H05B 6/705 using microwave tuning
• CPC Class Codes: H05B 6/76 Prevention of microwave leakage, e.g. door sealings
• CPC Class Codes: H05B 6/78 Arrangements for continuous movement of material

Abstract

An apparatus for drying ink deposited upon cut sheet of paper. The apparatus includes a microwave generating member to generate microwave energy for the ink and an applying member connected to said microwave generating member to apply resonating traveling microwaves to the paper. The applicator member includes a serpentine applicator for drying the ink and includes input slots and output slots for moving cut sheet of paper through the serpentine applicator. A transport member transports ink printed cut sheet paper stock from the input slot to the output slot by a belt running through the center of the applicator.

Claims

1. An apparatus for drying ink deposited on a cut sheet of paper, said apparatus comprising:

a microwave generating member being adapted to generate microwave energy of a predetermined frequency;

a resonant traveling wave applying member, having a length selected according to an integral number of wavelengths in said member at the predetermined frequency, including a serpentine applicator, connected to said microwave generating member, being adapted to apply microwave energy in the form of resonant traveling waves to the cut sheet of paper having ink deposited thereon; and

a transport member having a low dielectric constant for transporting the cut sheet of paper through said applying member to dry the ink deposited on the cut sheet of paper.

2. The apparatus of claim 1, wherein said transport member comprises a belt.

3. The apparatus of claim 2, wherein said applying member defines an input slot to receive a sheet of paper having deposited thereon liquid ink and defining an output slot to produce a sheet of paper on which substantially liquid free ink remains.

4. The apparatus of claim 3, wherein said applying member comprises a directional coupler connected between said microwave generating member and said serpentine applicator.

5. The apparatus of claim 4, wherein said microwave generating member generates microwaves having a power in the range of 500 to 1500 watts.

6. The apparatus of claim 5, wherein said serpentine applicator comprises:

a plurality of wall members; and

a plurality of U-shaped connecting members joining each of the wall members of said plurality of wall members to define a plurality of generally parallel waveguides.

7. The apparatus of claim 6, wherein the defined generally parallel waveguides range from 4 to 8 in number.

8. The apparatus of claim 6, wherein said serpentine applicator comprises a top member located on one side of said belt and a bottom member located on the opposite side of said belt.

9. The apparatus of claim 8, further including a guide member coupled to said top member to guide the cut sheet of paper from the input slot to the output slot.

10. The apparatus of claim 9, wherein said guide member comprises a polytetraflouroethylene string extending substantially perpendicular to the wall members and having one end thereof connected to said applying member in the region of the the input slot and the other end thereof connected to said applying member in the region of the output slot.

11. The apparatus of claim 10, wherein said top member and said bottom member are hingedly connected to provide access to the interior of said applying member.

12. The apparatus of claims 8, further comprising a drying member coupled to said top half to deliver a flow of air to the paper.

13. The apparatus of claim 12, wherein said top member defines a plurality of holes to permit delivery of air to the interior chamber of said applying member, each of said plurality of holes being of a size selected to reduce microwave leakage therefrom.

14. The apparatus of claim 13, wherein said drying member comprises a manifold defining a chamber attached to said top half and a blower coupled to said manifold to deliver air to the interior chamber.

15. The apparatus of claim 6, wherein said wall members comprise a single member shared by adjacent ones of the generally parallel waveguides.

16. The apparatus of claim 15, wherein said common wall members are of a thickness sufficient to prevent microwave passage through the slots between adjacent waveguides.

17. The apparatus of claim 16, wherein said U-shaped connecting members are optimized to reduce the standing wave ratio by optimizing the distance between the end of said wall member and the interior surface of said U-shaped connecting member.

18. The apparatus of claim 17, further comprising a lip member attached to said applying member at the input slot for reducing microwave leakage from said applying member.

19. The apparatus of claim 17, further comprising a lip member attached to said applying member at the output slot for reducing microwave leakage from said applying member.

20. A method for drying ink deposited on a cut sheet of paper, comprising the steps of:

applying microwave energy comprising resonating traveling microwaves to the deposited ink within no more than 3 seconds after depositing the ink on the cut sheet of paper with a microwave dryer including a traveling wave resonant circuit having an effective electrical length equivalent to an integral number of wavelengths, generating resonating traveling microwaves; and

removing excess liquid from the deposited ink within no more than 5 seconds after said applying step.

21. The method of claim 20, wherein said applying step includes applying microwave energy by a microwave dryer comprising a microwave generator, a directional coupler and a serpentine applicator, said directional coupler connected between said microwave generating member and said serpentine applicator.

22. The method of claim 21, wherein said applying step includes applying microwaves having a power in the range of about 500-1500 watts.

23. The method of claim 22, wherein said applying step includes applying microwave energy to the deposited ink within no more than 0.5 to 1.5 seconds after depositing the ink.

24. The method of claim 23, further comprising the step of passing the cut sheet of paper to the dryer at a speed of between about 2 inches to 20 inches per second.

25. The method of claim 24, wherein said removing step requires a time period of about 5 seconds to 0.5 seconds.

26. A printing machine, comprising:

an ink jet print head adapted to deposit ink on a cut sheet of paper;

a microwave dryer, associated with said ink jet print head, for drying the ink deposited on the cut sheet of paper deposited by said print head, said dryer including a microwave generating member being adapted to generate microwave energy of a predetermined frequency, and a resonating traveling wave applying member having a length selected according to an integral number of wavelengths in said member at the predetermined frequency, including a serpentine applicator, connected to said microwave generating member to apply microwave power in the form of resonant traveling waves to the cut sheet of paper having deposited thereon ink; and

a transport member having a low dielectric constant for transporting the cut sheet of paper through said applying member to dry the ink deposited on the cut sheet of paper.

27. The printing machine of claim 26, wherein said transport member comprises a belt.

28. The printing machine of claim 27, wherein said applying member defines an input slot to receive a sheet of paper having deposited thereon liquid ink and defining an output slot to output a sheet of paper having deposited thereon substantially liquid free ink.

29. The printing machine of claim 26, wherein said applying member comprise a directional coupler connected between said microwave generating member and said serpentine applicator.

30. The printing machine of claim 29, wherein said microwave generating member generates microwaves having a power in the range of 500 to 1500 watts.

31. The printing machine of claim 30, wherein said serpentine applicator comprises a plurality of wall members;

and

a plurality of U-shaped connecting members joining each of the wall members of said plurality of wall members to define a plurality of generally parallel waveguides.

32. The printing machine of claim 31, wherein the defined generally parallel waveguides range from 4 to 8 in number.

33. The apparatus of claim 27, wherein said ink jet printhead is adapted to deposit an ink composition including compounds designed to couple with microwave power.

34. The apparatus of claim 33, wherein said ink composition includes an aqueous liquid vehicle, a colorant, and an ionic compound at least partially ionizable in the liquid vehicle, said ink composition having a conductivity of at least about 10 millisiemens per centimeter.

35. A method of printing and drying ink on a cut sheet of paper comprising the steps of:

depositing ink on the cut sheet of paper by an ink jet printhead;

passing the cut sheet of paper to a microwave dryer, including a traveling wave resonant circuit having an effective electrical length equivalent to an integral number of wavelengths, immediately after the deposition of ink on the cut sheet of paper; and

heating the ink rapidly by microwave power comprising resonating traveling microwaves applied by the microwave dryer to evaporate excess liquid from the ink before substantial absorption into the paper within no more than 5 seconds from depositing ink on the paper.

36. The method of claim 35, wherein said heating step includes heating by microwaves applied by a microwave dryer comprising a microwave generator, a directional coupler and a serpentine, said directional coupler connected between said microwave generating member and said serpentine applicator.

37. The method of claim 36, wherein said heating step includes heating by microwaves having a power output in the range of about 500-1500 watts.

38. The method of claim 37, wherein the heating step includes evaporating liquid in the ink within about 5 seconds to 0.5 seconds from completion to said depositing step.

39. The method of claim 38, wherein the passing step includes the cut sheet of paper to the microwave dryer at a speed of between about 2 inches to 20 inches per second.

40. A method of printing paper with ink and drying the printed paper with microwave power applied with a serpentine applicator having a plurality of generally parallel guide sections, wherein the microwave power decreases from a first guide section to a last guide section, said method comprising the steps of:

depositing a slowly penetrating liquid ink on the cut sheet of paper by a printhead; and

passing the printed paper through the serpentine applicator to dry the ink thereon by applying microwave power comprising resonating traveling microwaves so that the printed paper passes through the last guide section first.

41. The method of claim 40, wherein said depositing step includes depositing the slowly penetrating liquid ink with a thermal ink jet printhead.