Patent US2274778A successfully refreshed from Google Patents.
US3789753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for printing of charge images
Assignee: Varian Medical Systems Inc
•
Filing: 1973-05-29
•
Granted: 1974-02-05
•
Expires: 1993-05-29
Abstract
Abstract An electrically isolated development electrode is disposed immediately adjacent a charge image bearing surface of a charge image bearing structure having a conductive backing. The charge image induces a second charge image in the development electrode and produces an image electric field in the development gap between the first and second charge images. The second charge image further induces a background charge distribution in the backing member of opposite sign to that of the first charge image. An insulative web is disposed in the development gap to receive electroscopic pigment particles for printing either a positive or a negative print of the first charge image. Additional copies may be printed on successively introduced insulative webs without dissipating the first charge image.
Inventors
- 👤 S Rutherford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:06
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/41; B41J2/415; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
232 words
An apparatus for toning an image corresponding to a charge image on an insulative charge retentive layer overlying an electrical conducting backing member, comprising the combination: an insulative charge retentive layer overlying an electrical conducting backing member; development electrode means which is electrically conductive and disposed adjacent the charge retentive surface defining a development gap therebetween which is sufficiently narrow to permit the charge image on the charge retentive surface to establish a corresponding electric field across the development gap to induce a charge image on the development electrode, the development electrode means being electrically isolated from the backing member and operating at an independent floating potential with respect thereto; an insulative web positioned in the development gap in spaced relationship from the charge retentive surface and from the development electrode means and dividing the development gap into two portions, one portion formed by the insulative web and the development electrode and the other portion formed by the insulative web and the charge retentive surface, the web receiving a charge image thereon by induction by means of the electric field extending across the development gap; and means for applying toner into at least one of the development gap portions, which toner migrates under the influence of the electric field towards at lEast one of the charge images to establish a toned image corresponding to the charge image on the charge retentive surface.
Claim 2
Independent Claim
232 words
An apparatus for toning an image corresponding to a charge image on an insulative charge retentive layer overlying an electrical conducting backing member, comprising the combination: an insulative charge retentive layer overlying an electrical conducting backing member; development electrode means which is electrically conductive and disposed adjacent the charge retentive surface defining a development gap therebetween which is sufficiently narrow to permit the charge image on the charge retentive surface to establish a corresponding electric field across the development gap to induce a charge image on the development electrode, the development electrode means being electrically isolated from the backing member and operating at an independent floating potential with respect thereto; an insulative web positioned in the development gap in spaced relationship from the charge retentive surface and from the development electrode means and dividing the development gap into two portions, one portion formed by the insulative web and the development electrode and the other portion formed by the insulative web and the charge retentive surface, the web receiving a charge image thereon by induction by means of the electric field extending across the development gap; and means for applying toner into at least one of the development gap portions, which toner migrates under the influence of the electric field towards at lEast one of the charge images to establish a toned image corresponding to the charge image on the charge retentive surface.
References Cited (Backward Citations)
US2633796A
Cited
US2725304A
Cited
US2952241A
Cited
US2885955A
Cited
US3096198A
Cited
US3306198A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |