US3678895A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic cascade development device for dry process electrophotography
Assignee: Ricoh Co Ltd
•
Filing: 1970-03-13
•
Granted: 1972-07-25
•
Expires: 1990-03-13
Abstract
Abstract Cascade development device for a dry process electrophotography includes a magnetic endless belt trained around a pair of rollers and a non-magnetic endless roller partially wrapped over the magnetic belt along its going pass and trained around a guide roller spaced apart from the upper one of the pair of rollers and adjacent to the upper end of an development of an electrophotographic recording medium in such a manner that the non-magnetic belt may be separate from the magnetic belt adjacent to the upper one of the pair of rollers. The developer is entrained and transported upon the non-magnetic belt and is freed from the magnetic field when the belts are separated so that the developer may be freely cascaded. Mixing means is provided for mixing the returned developer and guide roller oscillating means is also provided so as to uniformly cascade the developer.
Inventors
- 👤 Wasaburo Ohta
- 👤 Kazuhiko Kasuya
- 👤 Masayuki Yamauchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:24
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0801
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
209 words
A device for a dry process electrophotographic cascade development comprising a developer sump, a magnetic endless belt trained around a pair of spaced apart roller means, a non-magnetic endless belt partially wrapped over said magnetic endless belt along its going pass and trained around a guide roller means disposed in spaced apart relation from the upper one of said pair of roller means and adjacent to the upper end of a development zone of an electrophotographic recording medium overlaid upon the peripheral surface of a rotary drum in such a manner that said non-magnetic belt may be separated from said magnetic belt adjacent to said upper roller means, and drive means for driving at least said non-magnetic endless belt, said magnetic endless belt having means for generating the magnetic field through both of said magnetic and non-magnetic endless belts, whereby the developer in said sump is entrained upon said non-magnetic endless belt and transported to an area adjacent to said guide roller means and the free movement of said developer upon said non-magnetic endless belt being permitted upon said separation of said non-magnetic belt from said magnetic belt so that the developer may be freely cascaded over said development zone from an area adjacent to said guide roller reans.
Claim 2
Independent Claim
209 words
A device for a dry process electrophotographic cascade development comprising a developer sump, a magnetic endless belt trained around a pair of spaced apart roller means, a non-magnetic endless belt partially wrapped over said magnetic endless belt along its going pass and trained around a guide roller means disposed in spaced apart relation from the upper one of said pair of roller means and adjacent to the upper end of a development zone of an electrophotographic recording medium overlaid upon the peripheral surface of a rotary drum in such a manner that said non-magnetic belt may be separated from said magnetic belt adjacent to said upper roller means, and drive means for driving at least said non-magnetic endless belt, said magnetic endless belt having means for generating the magnetic field through both of said magnetic and non-magnetic endless belts, whereby the developer in said sump is entrained upon said non-magnetic endless belt and transported to an area adjacent to said guide roller means and the free movement of said developer upon said non-magnetic endless belt being permitted upon said separation of said non-magnetic belt from said magnetic belt so that the developer may be freely cascaded over said development zone from an area adjacent to said guide roller reans.
Claim 3
Dependent Claim
30 words
A device as specified in claim 1 wherein means is provided for oscillating said guide roller means so as to oscillate said non-magnetic endless belt when the developer is cascaded.
Claim 4
Dependent Claim
43 words
A device as specified in claim 1 wherein mixing means is provided for mixing the developer returned from said cascade over said recording medium into said developer sump and for directinG the developer toward the lower one of said pair of roller means.
Claim 5
Dependent Claim
43 words
A device as specified in claim 2 wherein mixing means is provided for mixing the developer returned from said cascade over said recording medium into said developer sump and for directing the developer toward the lower one of said pair of roller means.
Claim 6
Independent Claim
287 words
A device for a dry process electrophotographic cascade development comprising a developer sump, a magnetic endless belt trained around a pair of spaced apart roller means, a non-magnetic metallic belt partially wrapped over said magnetic endless belt along its going pass and trained around a pair of mutually spaced apart guide roller means disposed substantially at both ends of a development zone of a recording medium overlaid upon the peripheral surface of a rotary drum in such a manner that said non-magnetic metallic belt may be separated from said magnetic belt adjacent to the upper one of said pair of roller means and pass along said development zone in closely spaced apart relation therewith, a guide plate means for ensuring said pass of said non-magnetic metallic belt along said development zone in closely spaced apart relation therewith, and drive means for driving at least said non-magnetic metallic belt, mixing means for mixing the developer returned into said developer sump from said recording medium and for directing the developer toward the lower one of said pair of roller means, said magnetic endless belt having means for generating the magnetic field through both of said magnetic and non-magnetic metallic endless belts, whereby the developer in said sump is entrained upon said non-magnetic endless belt and transported to an area adjacent to the upper one of said pair of mutually spaced apart guide roller means, and the free movement of said developer upon said non-magnetic metallic endless belt being permitted when said non-magnetic metallic endless belt is separated from said magnetic endless belt so that the developer may be freely cascaded over said development zone from an area adjacent to the upper one of said pair of guide roller means.
Claim 7
Independent Claim
287 words
A device for a dry process electrophotographic cascade development comprising a developer sump, a magnetic endless belt trained around a pair of spaced apart roller means, a non-magnetic metallic belt partially wrapped over said magnetic endless belt along its going pass and trained around a pair of mutually spaced apart guide roller means disposed substantially at both ends of a development zone of a recording medium overlaid upon the peripheral surface of a rotary drum in such a manner that said non-magnetic metallic belt may be separated from said magnetic belt adjacent to the upper one of said pair of roller means and pass along said development zone in closely spaced apart relation therewith, a guide plate means for ensuring said pass of said non-magnetic metallic belt along said development zone in closely spaced apart relation therewith, and drive means for driving at least said non-magnetic metallic belt, mixing means for mixing the developer returned into said developer sump from said recording medium and for directing the developer toward the lower one of said pair of roller means, said magnetic endless belt having means for generating the magnetic field through both of said magnetic and non-magnetic metallic endless belts, whereby the developer in said sump is entrained upon said non-magnetic endless belt and transported to an area adjacent to the upper one of said pair of mutually spaced apart guide roller means, and the free movement of said developer upon said non-magnetic metallic endless belt being permitted when said non-magnetic metallic endless belt is separated from said magnetic endless belt so that the developer may be freely cascaded over said development zone from an area adjacent to the upper one of said pair of guide roller means.
Claim 8
Dependent Claim
30 words
A device as specified in claim 1 wherein said non-magnetic metallic endless belt comprises an endless belt made of fabrics or rubber with a thin non-magnetic metallic sheet laminated thereover.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |