US3248216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for half-tone electrophotography
Assignee: GAF Chemicals Corp
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Filing: 1961-03-28
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Granted: 1966-04-26
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Expires: 1981-03-28
Abstract
No abstract record available.
Inventors
- 👤 John W Weigl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:15
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/04027; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/102
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
113 words
A PROCESS OF ELECTROPHOTOGRAPHY WHICH COMPRISES UNIFORMLY ELECTROSTATICALLY CHARGING THE SURFACE OF A LAYER OF PHOTOCONDUCTIVE INSULATING MATERIAL SUPERPOSED ON AN ELECTRICALLY CONDUCTIVE LAYER, MECHANICALLY REMOVING THE CHARGE FROM CERTAIN AREAS ONLY OF SAID SURFACE BY ROLLING CONTACT WITH A SEPARATE ELECTRICALLY CONDUCTIVE GROUNDED ELEMENT HAVING A DOT PATTERN OF CONTACTMEANS ON AN ELECTRICALLY CONDUCTIVE, CYLINDRICAL SURFACE THEREOF, LEAVING THE CHARGE ON OTHER AREAS OF SAID SURFACE IN A PATTERN CORRESPONDING TO THE NEGATIVE OF THE SAID DOT PATTERN OF THE CONTACT MEANS, THEREAFTER EXPOSING SAID SURFACE TO LIGHT PASSING THROUGH AN IMAGE WHEREBY A HALF-TONE PATTERNED LATENT IMAGE IS PRODUCED ON SAID SURFACE AND DEVELOPING SAID LATENT IMAGE TO RENDER IT VISIBLE.
Claim 2
Dependent Claim
113 words
A PROCESS OF ELECTROPHOTOGRAPHY WHICH COMPRISES UNIFORMLY ELECTROSTATICALLY CHARGING THE SURFACE OF A LAYER OF PHOTOCONDUCTIVE INSULATING MATERIAL SUPERPOSED ON AN ELECTRICALLY CONDUCTIVE LAYER, MECHANICALLY REMOVING THE CHARGE FROM CERTAIN AREAS ONLY OF SAID SURFACE BY ROLLING CONTACT WITH A SEPARATE ELECTRICALLY CONDUCTIVE GROUNDED ELEMENT HAVING A DOT PATTERN OF CONTACTMEANS ON AN ELECTRICALLY CONDUCTIVE, CYLINDRICAL SURFACE THEREOF, LEAVING THE CHARGE ON OTHER AREAS OF SAID SURFACE IN A PATTERN CORRESPONDING TO THE NEGATIVE OF THE SAID DOT PATTERN OF THE CONTACT MEANS, THEREAFTER EXPOSING SAID SURFACE TO LIGHT PASSING THROUGH AN IMAGE WHEREBY A HALF-TONE PATTERNED LATENT IMAGE IS PRODUCED ON SAID SURFACE AND DEVELOPING SAID LATENT IMAGE TO RENDER IT VISIBLE.
Claim 3
Independent Claim
107 words
AN APPARATUS SUITABLE FOR USE IN ELECTROPHOTOGRAPHY COMPRISING A HOUSING, ELECTROSTATIC CHARGING MEANS WITHIN THE HOUSING AN ELECTRICALLY CONDUCTIVE GRAVURE ROLLER POSITIONED WITHIN THE HOUSING AND ELECTRICALLY CONNECTED TO GROUND, EXPOSURE MEANS COOPERATING WITH SAID HOUSING TO PROJECT LIGHT IMAGEWISE INTO THE SAID HOUSING, DEVELOPING MEANS WITHIN THE HOUSING AND MEANS FOR MOVING AN ELECTROPHOTOGRAPHIC SHEET THROUGH THE HOUSING FIRST PAST SAID CHARGING MEANS, WITH THE PHOTOCONDUCTIVE SURFACE OF SAID SHEET EXPOSED TO SAID CHARGING MEANS; THEN PAST SAID GRAVURE ROLLER IN MECHANICAL, ROLLING CONTRACT WITH THE PATTERN OF SAID ROLLER; THEN PAST SAID EXPOSURE MEANS AND FINALLY THROUGH SAID DEVELOPING MEANS AND OUT OF SAID HOUSING.
Claim 4
Independent Claim
107 words
AN APPARATUS SUITABLE FOR USE IN ELECTROPHOTOGRAPHY COMPRISING A HOUSING, ELECTROSTATIC CHARGING MEANS WITHIN THE HOUSING AN ELECTRICALLY CONDUCTIVE GRAVURE ROLLER POSITIONED WITHIN THE HOUSING AND ELECTRICALLY CONNECTED TO GROUND, EXPOSURE MEANS COOPERATING WITH SAID HOUSING TO PROJECT LIGHT IMAGEWISE INTO THE SAID HOUSING, DEVELOPING MEANS WITHIN THE HOUSING AND MEANS FOR MOVING AN ELECTROPHOTOGRAPHIC SHEET THROUGH THE HOUSING FIRST PAST SAID CHARGING MEANS, WITH THE PHOTOCONDUCTIVE SURFACE OF SAID SHEET EXPOSED TO SAID CHARGING MEANS; THEN PAST SAID GRAVURE ROLLER IN MECHANICAL, ROLLING CONTRACT WITH THE PATTERN OF SAID ROLLER; THEN PAST SAID EXPOSURE MEANS AND FINALLY THROUGH SAID DEVELOPING MEANS AND OUT OF SAID HOUSING.
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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) | 1969-04-25 | 1969-10-25 | 1970-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-25 | 1973-10-25 | 1974-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-25 | 1977-10-25 | 1978-04-26 | $7700.00 | Window Closed / Lapsed |