US4400078A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic copying apparatus and subsystems therefor
Assignee: Ricoh Co Ltd
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Filing: 1982-04-02
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Granted: 1983-08-23
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Expires: 2002-04-02
Abstract
Abstract An electrophotographic copying apparatus includes a photosensitive surface capable of retaining an electrostatic latent image for at least two cycles of the surface so a first copy of an original can be made upon scanning the original and the latent image can be recycled to produce a second copy of the same original during the return of the scanning mechanism. The apparatus includes an improved mechanism for driving the scanning mechanism, as well as improved developing and transfer stations.
Inventors
- 👤 Edward F. Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:42
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/28; G03G15/30; G03G15/06; G03G15/08; G03G15/095; G03G15/14; G03G15/16; G03G15/1665; G03G15/167
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
172 words
An electrophotographic copying apparatus including a photosensitive surface movable cyclically passed a plurality of processing stations and adapted to retain for two cycles thereof an electrostatic latent image formed on said photosensitive surface by exposing charged portions of said surface to a light image of an original, one of said stations including a developing station having means for forming two magnetic brushes of developing powder adapted to rotate in opposite directions to each other for wiping said latent image in one direction and then the other with said developing powder, including means for removing excess developing powder from said photosensitive surface including an elongate magnetic element having its poles formed on opposited longitudinal sides, said element being movable between a position placing one end of said element adjacent said surface for attracting excess developing powder and a more horizontal position placing the other end thereof into contact with a magnetic shunt to reduce the magnetic field strength at said one end to release the developing powder held thereby into a collecting area.
Claim 2
Dependent Claim
172 words
An electrophotographic copying apparatus including a photosensitive surface movable cyclically passed a plurality of processing stations and adapted to retain for two cycles thereof an electrostatic latent image formed on said photosensitive surface by exposing charged portions of said surface to a light image of an original, one of said stations including a developing station having means for forming two magnetic brushes of developing powder adapted to rotate in opposite directions to each other for wiping said latent image in one direction and then the other with said developing powder, including means for removing excess developing powder from said photosensitive surface including an elongate magnetic element having its poles formed on opposited longitudinal sides, said element being movable between a position placing one end of said element adjacent said surface for attracting excess developing powder and a more horizontal position placing the other end thereof into contact with a magnetic shunt to reduce the magnetic field strength at said one end to release the developing powder held thereby into a collecting area.
Claim 3
Dependent Claim
58 words
An apparatus according to claim 1, the first of said magnetic brushes to engage said photosensitive surface rotating to wipe said surface in a direction opposite to the movement of said surface, and the second of said magnetic brushes to engage said surface rotating to wipe said surface in the same direction as the movement of said surface.
Claim 4
Dependent Claim
32 words
An apparatus according to claim 2, said developing station further including means for forming a third magnetic brush of developing powder below said first two magnetic brushes for supplying developing powder thereto.
Claim 5
Independent Claim
31 words
An apparatus according to either of claims 1 or 2, said second magnetic brush being formed with a magnetic field lower in strength than the magnetic field forming said first brush.
Claim 6
Dependent Claim
45 words
An apparatus according to claim 1, said magnetic element being formed of a magnetized core material having pole faces held to longitudinal sides thereof, said pole faces extending beyond said core material at said one end of said element to increase the magnetic field there.
Claim 7
Dependent Claim
19 words
An apparatus according to claim 5, including a non-magnetic filler material held between the extended portions of said faces.
Claim 8
Dependent Claim
105 words
In an electrophotographic copying apparatus having a developing station for applying a magnetically attractable developing powder to a photosensitive surface carrying an electrostatic latent image, means for removing excess developing powder from said surface including an elongate magnetic element having its poles formed on opposite longitudinal sides, said element being movable between a position placing one end of said element adjacent said surface for attracting excess developing powder and a more horizontal position placing the other end thereof into contact with a magnetic shunt to reduce the magnetic field strength of said one end and release the developing powder held thereby into a collecting area.
Claim 9
Dependent Claim
105 words
In an electrophotographic copying apparatus having a developing station for applying a magnetically attractable developing powder to a photosensitive surface carrying an electrostatic latent image, means for removing excess developing powder from said surface including an elongate magnetic element having its poles formed on opposite longitudinal sides, said element being movable between a position placing one end of said element adjacent said surface for attracting excess developing powder and a more horizontal position placing the other end thereof into contact with a magnetic shunt to reduce the magnetic field strength of said one end and release the developing powder held thereby into a collecting area.
Claim 10
Dependent Claim
45 words
An apparatus according to claim 7, said magnetic element being formed of a magnetized core material having pole faces held to longitudinal sides thereof, said pole faces extending beyond said core material at said one end of said element to increase the magnetic field there.
Claim 11
Dependent Claim
19 words
An apparatus according to claim 8, including a non-magnetic filler material held between the extended portions of the faces.
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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) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |