Claims
- 1. An image forming apparatus, comprising:
- a first image bearing member on which a toner image can be formed;
- an intermediate transfer member onto which the toner image is transferable from said first image bearing member;
- wherein the toner image is further transferred onto a second image bearing member therefrom;
- wherein said intermediate transfer member comprises a conductive layer to which a voltage is applied, a surface layer on the conductive layer, and a volume resistivity of the surface layer is 10.sup.5 -10.sup.11 ohm.cm, wherein a voltage is set so that a current in a non-image portion during an image transfer operation from said first image bearing member to said intermediate transfer member is less than twice a current in an image portion.
- 2. An apparatus according to claim 1, wherein said surface layer is of elastic material.
- 3. An apparatus according to claim 1, wherein said surface layer has a volume resistivity of 10.sup.7 -10.sup.10 ohm.cm.
- 4. An apparatus according to claim 1, wherein an image transfer position where the toner image is transferred from said intermediate transfer member to said second image bearing member is substantially the same position as a transfer position where the toner image is transferred from said first image bearing member to said intermediate transfer member.
- 5. An apparatus according to claim 1, wherein said apparatus is selectively operable in a first mode in which the toner image is transferred from said first image bearing member onto said intermediate transfer member, and thereafter, the toner image is transferred from said intermediate transfer member to said second image bearing member, and in a second mode in which the second image bearing member is passed through between said first image bearing member and said intermediate transfer member to transfer the toner image from said first image bearing member to the second image bearing member.
- 6. An apparatus according to claim 5, wherein in the first mode, the transfer from said first image bearing member to said intermediate transfer member is carried out a plurality of times, and thereafter, a plurality of images on the intermediate transfer member is transferred all together onto the second image bearing member.
- 7. An apparatus according to claim 4, wherein said apparatus is operable such that a first toner image is transferred from said first image bearing member onto said intermediate transfer member, and thereafter, a second toner image is formed on said first image bearing member, and the first and second toner images can be simultaneously transferred onto opposite sides of the second image bearing member supplied between said first image bearing member and said intermediate transfer member.
- 8. An apparatus according to claim 1, wherein at a first transfer position where the image is transferred from said first image bearing member to said intermediate transfer member, a speed of said first image bearing member and a speed of said intermediate transfer member is different, and wherein at a second transfer position where the image is transferred from said intermediate transfer member to the second image bearing member, the speed of the intermediate transfer member and a speed of the second image bearing member are different.
- 9. An apparatus according to claim 1, further comprising transfer means for transferring the toner image from said intermediate transfer member onto the second image bearing member, constant current control means for supplying a constant current to said intermediate transfer member, and determining means for determining a voltage applied to said transfer means in accordance with a voltage V.sub.T provided during a constant current control operation.
- 10. An apparatus according to claim 9, wherein said transfer means is supplied with the following voltage V during the constant voltage control operation:
- V=aV.sub.T +b (a, b, constants including 0).
- 11. An apparatus according to claim 10, wherein the constants a and b are changed when the voltage V.sub.T is outside a predetermined range.
- 12. An apparatus according to claim 1, wherein the toner image is electrostatically transferred at a transfer position from said first image bearing member to said intermediate transfer member, and adjacent the transfer position, a curvature of said intermediate transfer member is smaller than a curvature of said first image bearing member.
- 13. An apparatus according to claim 1, wherein said apparatus is operable such that different color toner images are superposedly transferred from said first image bearing member onto said intermediate transfer member, and thereafter, the different color toner images are all together transferable to the second image bearing member from said first intermediate transfer member.
- 14. An apparatus according to claim 13, wherein said apparatus is capable of forming a full-color toner image on said second image bearing member.
- 15. An apparatus according to claim 1, wherein the image is transferred electrostatically onto said intermediate transfer member, and the image is electrostatically transferred onto the second image bearing member.
- 16. An apparatus according to claim 1, wherein said voltage is 2-5 KV.
- 17. An image forming apparatus comprising:
- a first image bearing member on which a toner image can be formed;
- an intermediate transfer member onto which the toner image is transferable from said first image bearing member;
- wherein said apparatus is selectively operable in a first mode in which the toner image is transferred from said first image bearing member to said intermediate transfer member, and thereafter, the toner image is transferred from said intermediate transfer member to the second image bearing member, and in a second mode in which a second image bearing member is passed between said first image bearing member and said intermediate transfer member to transfer the toner image from said first image bearing member onto the second image bearing member.
- 18. An apparatus according to claim 17, wherein an image transfer position where the toner image is transferred from said intermediate transfer member to said second image bearing member is substantially the same position as a transfer position where the toner image is transferred from said first image bearing member to said intermediate transfer member.
- 19. An apparatus according to claim 17, wherein in the first mode, the transfer from said first image bearing member to said intermediate transfer member is carried out a plurality of times, and thereafter, a plurality of images on the intermediate transfer member is transferred all together onto the second image bearing member.
- 20. An apparatus according to claim 18, wherein said apparatus is operable such that a first toner image is transferred from said first image bearing member onto said intermediate transfer member, and thereafter, a second toner image is formed on said first image bearing member, and the first and second toner images can be simultaneously transferred onto opposite sides of the second image bearing member supplied between said first image bearing member and said intermediate transfer member.
- 21. An apparatus according to claim 17, wherein at a first transfer position where the image is transferred from said first image bearing member to said intermediate transfer member, a speed of said first image bearing member and a speed of said intermediate transfer member is different, and wherein at a second transfer position where the image is transferred from said intermediate transfer member to the second image bearing member, the speed of the intermediate transfer member and a speed of the second image bearing member are different.
- 22. An apparatus according to claim 17, further comprising transfer means for transferring the toner image from said intermediate transfer member onto the second image bearing member, constant current control means for supplying a constant current to said intermediate transfer member, and determining means for determining a voltage applied to said transfer means in accordance with a voltage V.sub.T provided during a constant current control operation.
- 23. An apparatus according to claim 22, wherein said transfer means is supplied with the following voltage V during the constant voltage control operation:
- V=aV.sub.T +b (a, b, constants including 0).
- 24. An apparatus according to claim 23, wherein the constants a and b are changed when the voltage V.sub.T is outside a predetermined range.
- 25. An apparatus according to claim 17, wherein the toner image is electrostatically transferred at a transfer position from said first image bearing member to said intermediate transfer member, and adjacent the transfer position, a curvature of said intermediate transfer member is smaller than a curvature of said first image bearing member.
- 26. An apparatus according to claim 19, wherein said apparatus is capable of forming a full-color toner image on said second image bearing member.
- 27. An apparatus according to claim 17, wherein the image is transferred electrostatically onto said intermediate transfer member, and the image is electrostatically transferred onto the second image bearing member.
- 28. An image forming apparatus, comprising:
- a first image bearing member on which a toner image can be formed;
- an intermediate transfer member on which the toner image is transferable from said first image bearing member;
- transfer means for transferring the toner image from said intermediate transfer member onto the second image bearing member;
- constant current control means for supplying a constant current onto said intermediate transfer member;
- determining means for determining a voltage to be applied to said transfer means in accordance with a voltage provided in a constant current control operation.
- 29. An apparatus according to claim 28, wherein an image transfer position where the toner image is transferred from said intermediate transfer member to said second image bearing member is substantially the same position as a transfer position where the toner image is transferred from said first image bearing member to said intermediate transfer member.
- 30. An apparatus according to claim 28, wherein at a first transfer position where the image is transferred from said first image bearing member to said intermediate transfer member, a speed of said first image bearing member and a speed of said intermediate transfer member is different, and wherein at a second transfer position where the image is transferred from said intermediate transfer member to the second image bearing member, the speed of the intermediate transfer member and a speed of the second image bearing member are different.
- 31. An apparatus according to claim 28, wherein said transfer means is supplied with the following voltage V during the constant voltage control operation:
- V=aV.sub.T +b (a, b, constants including 0).
- 32. An apparatus according to claim 31, wherein the constants a and b are changed when the voltage V.sub.T is outside a predetermined range.
- 33. An apparatus according to claim 31, wherein toner images can be formed on both sides of the second image bearing member, and the constants a and b are determined in accordance with a number of image transfer operations to the second image bearing member.
- 34. An apparatus according to claim 28, wherein the toner image is electrostatically transferred at a transfer position from said first image bearing member to said intermediate transfer member, and adjacent the transfer position, a curvature of said intermediate transfer member is smaller than a curvature of said first image bearing member.
- 35. An apparatus according to claim 28, wherein said apparatus is operable such that different color toner images are superposedly transferred from said first image bearing member onto said intermediate transfer member, and thereafter, the different color toner images are all together transferable to the second image bearing member from said first intermediate transfer member.
- 36. An apparatus according to claim 35, wherein said apparatus is capable of forming a full-color toner image on said second image bearing member.
- 37. An apparatus according to claim 28, wherein the image is transferred electrostatically onto said intermediate transfer member, and the image is electrostatically transferred onto the second image bearing member.
- 38. An image forming apparatus, comprising:
- a first image bearing member on which a toner image can be formed;
- an intermediate transfer member on which the toner image is transferable from said first image bearing member at a first transfer position;
- wherein the toner image is transferred from said intermediate transfer member onto a second image bearing member at a second transfer position;
- wherein a first speed of said first image bearing member in the first transfer position is different from a second speed of said intermediate transfer member, and a third speed of said intermediate transfer member at the second transfer position is different from a fourth speed of the second image bearing member.
- 39. An apparatus according to claim 38, wherein in the first mode, the transfer from said first image bearing member to said intermediate transfer member is carried out a plurality of times, and thereafter, a plurality of images on the intermediate transfer member is transferred all together onto the second image bearing member.
- 40. An apparatus according to claim 38, wherein the second speed is larger than the first speed, and the third speed is larger than the fourth speed, or the second speed is smaller than the first speed, and the third speed is smaller than the fourth speed.
- 41. An apparatus according to claim 38, wherein said apparatus is operable such that different color toner images are superposedly transferred from said first image bearing member onto said intermediate transfer member, and thereafter, the different color toner images are all together transferable to the second image bearing member from said first intermediate transfer member.
- 42. An apparatus according to claim 41, wherein said apparatus is capable of forming a full-color toner image on said second image bearing member.
- 43. An apparatus according to claim 38, wherein the image is transferred electrostatically onto said intermediate transfer member, and the image is electrostatically transferred onto the second image bearing member.
Priority Claims (1)
Number |
Date |
Country |
Kind |
4-164226 |
May 1992 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 08/069,379, filed Jun. 1, 1993, now abandoned.
US Referenced Citations (13)
Continuations (1)
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Number |
Date |
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Parent |
69379 |
Jun 1993 |
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