Toner applicator for electrophotographic microimagery

• US 4,918,487 A
• Filed: 01/23/1989
• Issued: 04/17/1990
• Est. Priority Date: 01/23/1989
• Status: Expired due to Fees

• Current Assignee: Coulter Systems Corporation
• Original Assignee: Coulter Systems Corporation
• Inventors: Coulter, Joseph R. Jr.
• Primary Examiner(s): PRESCOTT, ARTHUR
• Application Number:
  US07/300,779
• Time in Patent Office: 449 Days
• Field of Search: 355/256, 355/257, 355/258, 355/261, 355/262, 355/77, 355/122
• US Class Current: 399/240
• CPC Class Codes: G03G 15/101 for wetting the recording material

Abstract

A method and apparatus for applying liquid toner to fractional areas of a photoconductive recording member in processes involving microimagery. The method includes the steps of providing a photoconductor disposed over a conductive substrate having at least one fractional area thereon that is to be toned, providing a carrier member having a conductive layer, electrostatically depositing liquid toner on the carrier member to form thereon a toner pre-deposit of desired density in an area corresponding to the fractional area to be toned on the photoconductor, contacting the toner pre-deposit on the carrier member with the fractional area on the photoconductor, and toning the fractional area on the photoconductor by transferring toner thereto from the toner pre-deposit so that the quantity of liquid transferred to the photoconductor is minimal and can be rapidly removed therefrom without affecting the toner pre-deposit on the photoconductor. The apparatus includes backing members for supporting the photoconductor and contacting the fractional areas on the photoconductor with the fractional toner predeposits on the carrier member.

Claims

1. A method of toning a fractional area on a photoconductor to a predetermined image density that prevents dispersion of any liquid toner or carrier liquid beyond the fractional area to be toned and is capable of rapid drying comprising the steps of:

providing a photoconductor disposed over a conductive substrate having at least one fractional area thereon that is to be toned;

providing a carrier member having a conductive layer;

electrostatically depositing liquid toner on said carrier member to form thereon a toner pre-deposit of desired density in an area substantially corresponding to said fractional area to be toned on said photoconductor;

contacting said toner pre-deposit on said carrier member with said fractional area on said photoconductor;

toning said fractional area on said photoconductor by transferring toner thereto from said toner pre-deposit so that the quantity of liquid transferred to said photoconductor is minimal and can be rapidly removed therefrom without affecting the toner deposit on said photoconductor.

2. The method as defined in claim 1 including providing a backing member for support of said photoconductor during contact with said carrier member.

3. The method as defined in claim 2 including providing a backing member for support of said carrier member during contact with said photoconductor.

4. The method as defined in claim 1 including reducing the liquid contained within said fractional area on said carrier member before toning.

5. The method as defined in claim 1 including applying a bias voltage between said conductive substrate of said photoconductor and a said conductive layer of said carrier member during transfer toning

6. The method as defined in claim 1 including forming said toner pre-deposits on said conductive surface with a depositing electrode.

7. The method as defined in claim 1 wherein said carrier member includes a dielectric layer on said conductive layer and including forming said toner pre-deposits on said dielectric layer with a depositing electrode.

8. The method as defined in claim 1 wherein said carrier member includes a dielectric layer on said conductive layer and including forming said toner pre-deposits on said dielectric layer by electrostatically charging the dielectric in fractional areas, followed by liquid toning.

9. The method as defined in claim 1 wherein said carrier member is a flexible belt.

10. The method as defined in claim 1 wherein said carrier member is a disc.

11. The method as defined in claim 1 including separating said photoconductor from said carrier member after toning.

12. The method as defined in claim 1 including removing any remaining parts of said pre-deposit from said carrier member after toning.

13. The method as defined in claim 11 wherein after separating said photoconductor from said carrier member said method further includes transferring the toner deposit on said photoconductor to another surface, cleaning the photoconductor, charging the photoconductor, and imaging the photoconductor with a desired image.

14. The method as defined in claim 13 wherein said photoconductor is a flexible belt movable between designated positions to accomplish said transferring, cleaning, charging and imaging.

15. A toner applicator for toning a fractional area on a photoconductor to a predetermined image density that prevents dispersion of any liquid toner or carrier liquid beyond the fractional area to be toned and is capable of rapid drying comprising:

a photoconductor disposed over a conductive substrate having at least one fractional area thereon that is to be toned;

a carrier member having a conductive layer and electrostatically deposited liquid toner thereon to form a toner pre-deposit thereon of desired density in an area corresponding to said fractional area to be toned on said photoconductor, said carrier member being in close proximity to said photoconductor;

means for contacting said toner deposit on said carrier member with said fractional area on said photoconductor; and

means for toning said fractional area on said photoconductor by transferring toner thereto from said toner pre-deposit so that the quantity of liquid transferred to said photoconductor is minimal and can be rapidly removed therefrom without affecting the toner deposit on said photoconductor.

16. The toner applicator as defined in claim 15 including means for reducing the liquid contained within said fractional area on said carrier member.

17. The toner applicator as defined in claim 16 wherein said means for toning includes means for applying a bias voltage between said conductive substrate of said photoconductor and said conductive layer of said carrier member.

18. The toner applicator as defined in claim 15 including a depositing electrode for forming said toner pre-deposits on said conductive layer.

19. The toner applicator as defined in claim 18 wherein said carrier member is a flexible belt.

20. The toner applicator as defined in claim 18 wherein said carrier member is a disc having a planar face.

21. The toner applicator as defined in claim 20 wherein said disc includes protruding conductive toning areas on its face.

22. The toner applicator as defined in claim 15 wherein said carrier member includes a dielectric layer on said conductive layer.

23. The toner applicator as defined in claim 22 including a depositing electrode for forming said toner pre-deposits on said dielectric layer.

24. The toner applicator as defined in claim 23 wherein said carrier member is a flexible belt.

25. The toner applicator as defined in claim 23 wherein said carrier member is a disc having a planar face.

26. The toner applicator as defined in claim 25 wherein said disc includes protruding dielectric toning areas on its face.

27. The toner applicator as defined in claim 22 including means for electrostatically charging said dielectric in fractional areas to form said toner pre-deposits on said dielectric layer and further including means for liquid toning said pre-deposits.

28. The toner applicator as defined in claim 27 wherein said carrier member is a flexible belt.

29. The toner applicator as defined in claim 27 wherein said carrier member is a disc having a planar face.

30. The toner applicator as defined in claim 29 wherein said disc includes protruding conductive toning areas on its face.

31. The toner applicator as defined in claim 15 wherein said carrier member includes a plurality of toning areas thereon and includes means for positioning a desired toning area in close proximity to a desired fractional area of said photoconductor for contact and transfer thereto.

32. The toner applicator as defined in claim 15 including first backing means for providing support to said photoconductor during contact with said carrier member.

33. The toner applicator as defined in claim 32 including second backing means for providing support to said carrier member during contact with said photoconductor.

34. The toner applicator as defined in claim 33 wherein said means for contacting includes means for moving said first backing means against said photoconductor to position said photoconductor against said carrier member.

35. The toner applicator as defined in claim 33 wherein said means for contacting includes means for moving said second backing means against said carrier member to position said carrier member against said photoconductor.

36. The toner applicator as defined in claim 33 wherein said means for contacting includes means for simultaneously moving both of said first and second backing means to position said photoconductor against said carrier member.

37. The toner applicator as defined in claim 36 wherein each of said first and second backing means include a plunger having an engagement head on its distal end, said engagement head being resilient in order to obtain uniform contact over the entire fractional area of said photoconductor.

38. The toner applicator as defined in claim 37 wherein said engagement head includes a flexible bag member and said means for moving includes a compressed air means that is activated to inflate said bag and provide said contact between said photoconductor and said carrier member, and said compressed air means is activated to deflate said bag and return said photoconductor to a position proximate to said carrier member.

39. The toner applicator as defined in claim 38 wherein the distal end of each plunger includes a cavity therein and said flexible bag is positioned partially within said cavity during inflation and deflation.

40. The toner applicator as defined in claim 15 including means for removing any remaining parts of said predeposit from said carrier member after toning.

41. The toner applicator as defined in claim 15 wherein said photoconductor is a rectangular microfiche.

42. The toner applicator as defined in claim 15 wherein said photoconductor is a belt.

43. The toner applicator as defined in claim 42 including a photoconductor transfer station, cleaning station, charging station and imaging station and means for moving said belt between said stations.