US3159718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for electrostatic recording and reproducing
Assignee: IIT Research Institute
•
Filing: 1959-10-05
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Granted: 1964-12-01
•
Expires: 1979-10-05
Abstract
No abstract record available.
Inventors
- 👤 Donald E Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:02
CPC Classifications
G; G11; G11B; G11B9/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
95 words
APPARATUS FOR INJECTING CHARGES INTO A RECORD MEDIUM INCLUDING A PRE-BIAS ELECTRODE ARRANGED AT ONE SIDE OF THE MEDIUM TO FIRST INJECT A DIRECT CURRENT PREBIAS CHARGE INTO OPPOSED SUBSURFACE REGIONS OF THE MEDIUM, A RECORD ELECTRODE ARRANGED OT THEREAFTER ALTER THE INJECTED PRE-BIAS CHARGE IN ACCORDANCE WITH A SIGNAL TO BE RECORDED, A COMMON BACKING ELECTRODE ARRANGED TO COOPERATE WITH BOTH OF SAID PRE-BIAS AND RECORD ELECTRODES ON THE OPPOSITE SIDE OF THE MEDIUM, AND MEANS FOR ADJUSTING SAID COMMON BACKING ELECTRODE WITH RESPECT TO THE OTHER ELECTRODES TO DIFFERENTIALLY ALTER THE COOPERATION THEREWITH.
References Cited (Backward Citations)
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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) | 1967-12-01 | 1968-06-01 | 1968-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-12-01 | 1972-06-01 | 1972-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-12-01 | 1976-06-01 | 1976-12-01 | $7700.00 | Window Closed / Lapsed |