Claims
- 1. A color image forming apparatus for forming a color image by transferring color toners onto a transfer material, comprising:
- an endless loop electrophotographic photosensitive member having a loop length greater than a maximum length of images to be formed and transferred onto a transfer material;
- color latent image forming means provided with optical means for projecting optical information corresponding to color images, for forming electrostatic latent images respectively corresponding to color images, on said photosensitive member;
- plural color development means provided along the moving direction of said photosensitive member, opposed to said photosensitive member, and adapted to develop latent images formed on said photosensitive member with color toners supplied thereto by developing rollers, thereby forming color toner images; and
- an endless loop transfer member adapted to effect an endless movement in synchronization with the electrophotographic photosensitive member and having a loop length A, in the moving direction of the photosensitive member, capable of simultaneously supporting two images of the maximum length L, and adapted to receive transfer of color toner images formed on said photosensitive member, in succession at a transfer position of said transfer member;
- wherein a relation:
- d.sub.p >d.sub.s .gtoreq.2r+(V.sub.p /V.sub.s).pi.r
- is substantially satisfied, where A is the loop length of said transfer member in said endless moving direction, R is the radius and V.sub.p is the peripheral speed of the transfer member when it is converted as circular, r is the radius and V.sub.s is the peripheral speed of the developing rollers of said development means, d.sub.p is a distance between two successive images on said transfer member at a position corresponding to a time during which said development means changes from one developing roller having one color toner to another developing roller having another color toner, and d.sub.s is the distance between the developing rollers along the moving direction of the photosensitive member.
- 2. An apparatus according to claim 1, wherein
- d.sub.p >d.sub.s .gtoreq.2r+(V.sub.p /V.sub.s).pi.r.
- 3. An apparatus according to claim 1, wherein a sheet-shaped transfer material is supplied from supply means and is supported on said transfer member, and the color toner images are transferred from the photosensitive member in succession onto said transfer material.
- 4. An apparatus according to claim 1, wherein color toner images are transferred in succession from the photosensitive member directly onto said transfer member, and a completed color toner image formed on said transfer member is collectively transferred onto the transfer material.
- 5. An apparatus according to claim 1, wherein said optical information projecting means is a digital optical system.
- 6. An apparatus according to claim 1, wherein said photosensitive member and said transfer member have a same length in the moving direction thereof.
- 7. An apparatus according to claim 6, wherein said photosensitive member has a photosensitive layer composed of organic polymer.
- 8. A color image forming apparatus according to claim 1, wherein d.sub.p at a position where the developing device is exchanged is larger than (2.pi.R-2L)/2.
- 9. A color forming apparatus for forming a color image by transferring color toners onto a transfer material, comprising:
- a rotating electrophotographic photosensitive drum having a peripheral length greater than a maximum length L of images to be formed on a transfer drum;
- a color latent image forming device provided with a charge device and an optical device for projecting optical information corresponding to color images, for forming electrostatic latent images respectively corresponding to color images, on said photosensitive drum;
- plural color developing devices provided along the rotating direction of said photosensitive drum and opposed to said photosensitive drum, and adapted to develop latent images formed on said photosensitive member with color toners supplied thereto by developing rollers, thereby forming color toner images; and
- a transfer drum rotating in synchronization with the electrophotographic photosensitive drum and provided with a peripheral length A, in the rotating direction of the photosensitive drum, capable of simultaneously supporting two images of the maximum length L, and adapted to receive transfer of color toner images formed on said photosensitive drum, in succession at a transfer position of said transfer drum;
- wherein a relation:
- d.sub.p >d.sub.s .gtoreq.2r+(V.sub.p /V.sub.s).pi.r
- is substantially satisfied, where A is the peripheral length of said transfer drum in said rotating direction, R is the radius and V.sub.p is the peripheral speed of said transfer drum, r is the radius and V.sub.s is the peripheral speed of the developing rollers of said development devices, d.sub.p is a distance between two successive images on said transfer drum at a position corresponding to a time during which said developing devices change from one developing roller having one color toner to another developing device having another color toner, and d.sub.s is the distance between the developing rollers along the rotating direction of the photosensitive drum.
- 10. An apparatus according to claim 9, wherein
- d.sub.p >d.sub.s .gtoreq.2r+(V.sub.p /V.sub.s).pi.r.
- 11. An apparatus according to claim 9, wherein a sheet-shaped transfer material is supplied from supply means and is supported on said transfer drum, and the color toner images are transferred from the photosensitive drum in succession onto said transfer material.
- 12. An apparatus according to claim 9, wherein color toner images are transferred in succession from the photosensitive drum directly onto said transfer drum, and a completed color toner image formed on said transfer drum is collectively transferred onto the transfer material.
- 13. An apparatus according to claim 9, wherein said optical information projecting means is a digital optical system.
- 14. An apparatus according to claim 9, wherein said photosensitive drum and said transfer drum have a same length in the rotating direction thereof.
- 15. An apparatus according to claim 14, wherein said photosensitive drum has a photosensitive layer composed of organic polymer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
5-083783 |
Mar 1993 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 08/503,540 filed Jul. 18, 1995, which is a continuation of application Ser. No. 08/213,501 filed Mar. 16, 1994, both now abandoned.
US Referenced Citations (5)
Continuations (2)
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Number |
Date |
Country |
Parent |
503540 |
Jul 1995 |
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Parent |
213501 |
Mar 1994 |
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