US3539712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording and reproducing apparatus and methods for simultaneously reproducing separate information
Assignee: Electronic Research Corp
•
Filing: 1966-01-24
•
Granted: 1970-11-10
•
Expires: 1986-01-24
Abstract
No abstract record available.
Inventors
- 👤 Kenneth D Stephens Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:47
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/78; H04N5/782; H04N9/00; H04N9/79; H04N9/80; H04N9/81
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3157739A
Cited
US2856462A
Cited
US2856463A
Cited
US3213204A
Cited
US3152223A
Cited
US3267207A
Cited
US3359365A
Cited
US3470316A
Cited
US3470315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |