Electrophotographic toner transfer and fusing apparatus

• US 3,893,761 A
• Filed: 10/04/1973
• Issued: 07/08/1975
• Est. Priority Date: 11/02/1972
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Robert A. Moore, William R. Buchan
• Inventors: Buchan, William R., Moore, Robert A.
• Primary Examiner(s): Matthews, Samuel S.
• Assistant Examiner(s): Hutchison, Kenneth C.
• Application Number:
  US05/403,696
• Time in Patent Office: 642 Days
• Field of Search: 355/3R,3DD,17 96/1.4 117/17.5,21 118/59,60,101,102,106,202,641 74/231R,232
• US Class Current: 399/308
• CPC Class Codes: G03G 15/1605 using at least one intermediate support G03G15/1625 takes precedence
• CPC Class Codes: G03G 15/2003 using heat

Abstract

Apparatus is disclosed for transferring non-fused xerographic toner images from a first support material, such as a photoconductive insulating surface, to a second support material, such as paper, and fusing the toner images to the second support material. Such apparatus includes an intermediate transfer member having a smooth surface of low surface free energy and a hardness of from 3 to 70 durometers. The intermediate transfer member can be, for example, a 0.1-10 mil layer of silicone rubber coated onto a polyimide support. The member can be formed into belt or drum configuration. Toner images are transferred from the first support material to the intermediate transfer member; this can be by any conventional transfer method, but pressure transfer is preferred. Next, the toner image is heated on the intermediate transfer member to at least its melting point temperature. Preferably the heating is selective, and one means of selectively heating toner is to provide radiant heating means and a belt formed from a transparent silicone rubber on a reflecting intermediate member support. After the toner is heated, second support material is brought into pressure contact with hot toner whereby toner is transferred and fused to the second support material. In preferred embodiments, a pressure applying element is used to provide a pressure pulse which has a steep rise time at the point where the intermediate transfer member and second support material come into contact. A method of transferring and fusing toner images is also disclosed.

Claims

1. An apparatus for transferring a non-fused xerographic toner image from a first support material to a second support material and fusing the toner image to the second support material, comprising, in combination:

a. an intermediate transfer member positioned to receive toner from said first support material, said intermediate transfer member having a smooth surface with a surface free energy of below about 40 dynes per centimeter, a hardness of from about 3 to about 70 durometers, and a heat capacity of below about 3.1 X 10 3 cal/cm2/*C.;

b. means for transferring toner from said first support material to said intermediate transfer member;

c. means for heating toner on said intermediate transfer member to a temperature at which it flows prior to transfer to said second support material;

d. means for supplying second support material; and

, e. means for bringing said second support material into pressure contact with heated toner on said intermediate transfer member in a manner whereby toner is transferred and fused to the second support material.

2. An apparatus of claim 1 wherein said means for heating toner comprises means for selectively heating toner to at least its melting point.

3. An apparatus of claim 2 wherein said means for bringing includes a specific pressure applying element which provides a pressure pulse having a sharp rise time.

4. An apparatus of claim 3 wherein said pressure applying element comprise a pressure bar.

5. An apparatus of claim 3 wherein said pressure applying element comprises a pinch roller having a relatively small diameter.

6. An apparatus of claim 2 wherein said intermediate transfer member has an elastomeric surface.

7. An apparatus of claim 1 wherein said intermediate transfer member has an elastomeric surface.

8. An apparatus of claim 6 wherein said intermediate transfer member is a drum.

9. An apparatus of claim 6 wherein said elastomeric surface comprises a silicone rubber.

10. An apparatus of claim 9 wherein said intermediate transfer member is a flexible belt positioned to come into pressure contact with said second support Material.

11. An apparatus of claim 10 wherein said intermediate transfer member has a substrate formed from a film which has good mechanical properties at a temperature of about 175*C.

12. An apparatus of claim 11 wherein said belt has a substrate comprising polyimide film.

13. An apparatus of claim 12 wherein said substrate is coated with a reflecting layer.

14. An apparatus of claim 10 wherein said intermediate transfer belt comprises a polyimide substrate, a reflecting layer, and a transparent silicone rubber, said polyimide substrate having a thickness of from about 0.5 mils to about 5 mils and said silicone rubber having a thickness of from about 0.1 mils to about 10 mils.

15. An apparatus of claim 14 wherein said second support material comprises paper.

16. An apparatus of claim 1 wherein said first support material comprises a photoconductive insulating surface.

17. An apparatus of claim 15 wherein said first support material comprises a photoconductive insulating surface.

18. An apparatus of claim 17 wherein said photoconductive insulating surface comprises zinc oxide.

19. An apparatus of claim 17 wherein said photoconductive insulating surface comprises vitreous selenium.

20. An apparatus of claim 17 wherein said means for bringing includes means for providing an extended zone subsequent to the specific pressure applying element in which said intermediate transfer member and said second support material remain in contact.

21. An apparatus of claim 20 wherein said means for providing cause said intermediate transfer member and said second support member to remain in contact for at least about 0.5 seconds.

22. An apparatus especially suitable for use in electrophotographic copying processes wherein multiple toner images are transferred from a first support material to a second support material for each exposure of the photoconductor, comprising:

a. an intermediate transfer member, at least a portion of which is positioned closely adjacent to said first support material, said intermediate transfer member having a smooth surface with a surface free energy of below about 40 dynes per centimeter, a hardness of from about 3 to about 70 durometers, and a heat capacity of below about 3.1 X 10 3 calories/cm2/*C.;

b. means for bringing said intermediate transfer member into pressure contact with said first support material including means to vary the amount of pressure between said first support material and said intermediate transfer member whereby the amount of toner transferred from said first support material to said intermediate transfer member can be controlled;

c. means for heating toner transferred to said intermediate transfer member to a temperature at which it flows;

d. means for supplying second support material;

e. means for bringing said second support material into pressure contact with toner on said intermediate transfer member whereby toner is transferred and fused to said second support material; and

, f. means for retoning portions of the toner image remaining on said first support material after it contacts said intermediate transfer member.

23. An apparatus of claim 22 wherein said intermediate transfer member has a surface formed from an elastomer.

24. An apparatus of claim 23 wherein said elastomer comprises silicone rubber.

25. An apparatus of claim 24 wherein said means for heating toner comprises means for selectively heating toner.

26. An apparatus of claim 25 wherein said first support material comprises a photoconductive insulating material.