US5063412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Development apparatus using an electromagnet to prevent development in the non-operative mode
Assignee: Xerox Corp
•
Filing: 1990-09-26
•
Granted: 1991-11-05
•
Expires: 2010-09-26
Abstract
Abstract An apparatus which develops a latent image recorded on a photoconductive member with developer material. The developer material is transported by a tubular member into a development zone. Developer material is attracted to the surface of the tubular member by a stationary magnet. In the operative mode, a weak magnetic field is formed in the development zone which releases the developer material from the surface of the tubular member so that the latent image attracts the developer material thereto. In the non-operative mode, an electromagnet is energized to decrease the magnetic field gradients in the development zone so as to decrease the tangential force on the surface of the tubular member preventing the developer material from moving therewith. The tubular member rotates in the opposite direction to the direction of rotation during development. With the electromagnet energized, the developer material moves with the tubular member away from the development zone to position the bare surface of the tubular member in the developing zone to prevent development of the latent image.
Inventors
- 👤 Mark J. Hirsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:10
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0921
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
170 words
An apparatus for developing a latent image recorded on a member with developer material, including: means for transporting the developer material into a development zone, in the operative mode, and removing developer material from the development zone, in the non-operative mode, so as to develop the latent image recorded on the member with developer material in the operative mode and prevent development thereof in the non-operative mode; means for attracting the developer material to said transporting means, said attracting means includes a magnet operatively associated with said transporting means to attract developer material thereto, said magnet being adapted to generate a weak magnetic field in the development zone; and means, operable in the non-operative mode, for changing the attraction in the development zone between the developer material and said transporting means so that the developer material moves with said transporting means away from the development zone, said changing means includes an electromagnet adapted to be energized in the non-operative mode to decrease the magnet field gradients in the development zone.
Claim 2
Independent Claim
170 words
An apparatus for developing a latent image recorded on a member with developer material, including: means for transporting the developer material into a development zone, in the operative mode, and removing developer material from the development zone, in the non-operative mode, so as to develop the latent image recorded on the member with developer material in the operative mode and prevent development thereof in the non-operative mode; means for attracting the developer material to said transporting means, said attracting means includes a magnet operatively associated with said transporting means to attract developer material thereto, said magnet being adapted to generate a weak magnetic field in the development zone; and means, operable in the non-operative mode, for changing the attraction in the development zone between the developer material and said transporting means so that the developer material moves with said transporting means away from the development zone, said changing means includes an electromagnet adapted to be energized in the non-operative mode to decrease the magnet field gradients in the development zone.
Claim 3
Dependent Claim
25 words
An apparatus according to claim 1, wherein said transporting means includes a rotatably mounted tubular member having said magnet disposed interiorly thereof and spaced therefrom.
Claim 4
Dependent Claim
22 words
An apparatus according to claim 2, wherein said magnet has a slot opposed from the development zone with said electromagnet mounted therein.
Claim 5
Dependent Claim
38 words
An apparatus according to claim 3, further including means for rotating said tubular member in a first direction when in the operative mode and in a second direction, opposed to the first direction, when in the non-operative mode.
Claim 6
Dependent Claim
11 words
An apparatus according to claim 4, wherein said magnet is stationary.
Claim 7
Dependent Claim
179 words
An electrophotographic printing machine adapted to have an electrostatic latent image recorded on a photoconductive member developed with developer material, wherein the improvement includes: means for transporting the developer material into a development zone, in the operative mode, and removing developer material from the development zone, in the non-operative mode, so as to develop the latent image recorded on the member with developer material in the operative mode and prevent development thereof in the non-operative mode; means for attracting the developer material to said transporting means, said attracting means includes a magnet operatively associated with said transporting means to attract developer material thereto, said magnet being adapted to generate a weak magnetic field in the development zone; and means, operable in the non-operative mode, for changing the attraction in the development zone between the developer material and said transporting means so that the developer material moves with said transporting means away from the development zone, said changing means includes an electromagnet adapted to be energized in the non-operative mode to decrease the magnet field gradients in the development zone.
Claim 8
Dependent Claim
179 words
An electrophotographic printing machine adapted to have an electrostatic latent image recorded on a photoconductive member developed with developer material, wherein the improvement includes: means for transporting the developer material into a development zone, in the operative mode, and removing developer material from the development zone, in the non-operative mode, so as to develop the latent image recorded on the member with developer material in the operative mode and prevent development thereof in the non-operative mode; means for attracting the developer material to said transporting means, said attracting means includes a magnet operatively associated with said transporting means to attract developer material thereto, said magnet being adapted to generate a weak magnetic field in the development zone; and means, operable in the non-operative mode, for changing the attraction in the development zone between the developer material and said transporting means so that the developer material moves with said transporting means away from the development zone, said changing means includes an electromagnet adapted to be energized in the non-operative mode to decrease the magnet field gradients in the development zone.
Claim 9
Dependent Claim
26 words
A printing machine according to claim 6, wherein said transporting means includes a rotatably mounted tubular member having said magnet disposed interiorly thereof and spaced therefrom.
Claim 10
Dependent Claim
23 words
A printing machine according to claim 7, wherein said magnet has a slot opposed from the development zone with said electromagnet mounted therein.
Claim 11
Dependent Claim
39 words
A printing machine according to claim 8, further including means for rotating said tubular member in a first direction when in the operative mode and in a second direction, opposed to the first direction, when in the non-operative mode.
Claim 12
Dependent Claim
12 words
A printing machine according to claim 9, wherein said magnet is stationary.
References Cited (Backward Citations)
US3257224A
Cited
US4499851A
Cited
US4465356A
Cited
US4565437A
Cited
US4537494A
Cited
US4641946A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-04 | 1995-05-06 | 1995-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-04 | 1999-05-06 | 1999-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-04 | 2003-05-06 | 2003-11-05 | $7700.00 | Window Closed / Lapsed |