US3902800A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copying system, method and components
Assignee: Bell and Howell Co
•
Filing: 1974-01-30
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Granted: 1975-09-02
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Expires: 1994-01-30
Abstract
Abstract An electrophotographic (or magnegraphic) copying system is disclosed which employs a doner sheet bearing toner particles adhered by electrostatic charge on one or both surfaces thereof, a photoresponsive member having a copy surface on which a charge image is formed, and electrically insulating liquid for application to the imaged surface whereby toner particles migrate from the doner sheet to the copy surface for fixing thereon.
Inventors
- 👤 Terry G Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:41
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0806; G03G15/22; G03G15/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
133 words
An improved copying system comprising, in combination: an elongate donor sheet of insulating material having a donor surface bearing toner particles uniformly adhered to said surface by electrostatic charge; a copy member having a copy surface; means for charging said copy surface; means for selectively dissipating said charge to form a charge image on said copy surface; storage means containing an electrically insulating liquid capable of stripping said toner particles from said donor surface for migration to said charged-imaged surface; applicator means for applying said liquid as a layer to said copy surface when said copy surface bears said charge image; means for bringing said donor surface and said liquid layer on said copy surface into contact; and means for fixing said toner particles as a permanent visible image on said copy surface.
Claim 2
Dependent Claim
133 words
An improved copying system comprising, in combination: an elongate donor sheet of insulating material having a donor surface bearing toner particles uniformly adhered to said surface by electrostatic charge; a copy member having a copy surface; means for charging said copy surface; means for selectively dissipating said charge to form a charge image on said copy surface; storage means containing an electrically insulating liquid capable of stripping said toner particles from said donor surface for migration to said charged-imaged surface; applicator means for applying said liquid as a layer to said copy surface when said copy surface bears said charge image; means for bringing said donor surface and said liquid layer on said copy surface into contact; and means for fixing said toner particles as a permanent visible image on said copy surface.
Claim 3
Dependent Claim
28 words
The system of claim 1 wherein said toner particles are held on said donor surface by forces weaker than the charge attraction afforded by said imaged copy surface.
Claim 4
Dependent Claim
16 words
The system of claim 2 wherein said copy member comprises at least one elongate, flexible sheet.
Claim 5
Dependent Claim
43 words
The system of claim 3 wherein said copy member, said donor sheet and said insulating liquid are in separate compartments and wherein said applicator means is positioned to apply said liquid to said imaged copy sheet immediately before contact with said donor sheet.
Claim 6
Dependent Claim
37 words
The system of claim 3 wherein both sides of said donor sheet bear said toner particles adherent thereto and wherein said donor sheet is disposed in a cartridge providing access to both sides of said donor sheet.
Claim 7
Dependent Claim
14 words
The system of claim 3 wherein said toner particles include thermoplastic binder transferable therewith.
Claim 8
Dependent Claim
20 words
The system of claim 3 wherein said toner particles include plastic binder soluble in said layer of electrically insulating liquid.
Claim 9
Dependent Claim
27 words
The system of claim 2 wherein said system includes means for providing an external electrical field adjacent said donor surface during said migration to facilitate the same.
Claim 10
Dependent Claim
39 words
The system of claim 2 wherein said charge image is an electrostatic charge image and said system includes means for providing an external electrical field adjacent said copy surface for reversal of said charge image on said copy surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-01 | 1979-03-03 | 1979-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-01 | 1983-03-03 | 1983-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-01 | 1987-03-03 | 1987-09-02 | $7700.00 | Window Closed / Lapsed |