Patent US3423540A successfully refreshed from Google Patents.
US3423540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Record-reproduce circuit
Assignee: International Business Machines Corp
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Filing: 1965-08-04
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Granted: 1969-01-21
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Expires: 1985-08-04
Abstract
No abstract record available.
Inventors
- 👤 Donald Wortzman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:50
CPC Classifications
G; G01; G01R; G01R17/00; A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/318; A61B5/333; A61B5/336; G06; G06G; G06G7/00; G06G7/04; G11; G11B; G11B20/00; G11B20/22; G11B20/225
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
A SYSTEM FOR RECORDING AND PLAYING BACK ANALOG SIGNALS COMPRISING, A FIRST IMPEDANCE MEANS A SECOND IMPEDANCE MEANS, AN AMPLIFIER MEANS, A RECORDING MEANS, AND A SWITCHING MEANS CONNECTED TO SAID FIRST IMPEDANCE MEANS, SAID SECOND IMPEDANCE MEANS, SAID AMPLIFIER MEANS, AND SAID RECORDING MEANS, SAID SWITCHING MEANS HAVING A FIRST SWITCH POSITION FOR CONNECTING SAID FIRST IMPEDANCE MEANS, SAID AMPLIFIER MEANS, AND SAID RECORDING MEANS IN SERIES CIRCUIT AND SAID AMPLIFIER MEANS AND SAID SECOND IMPEDANCE MEANS IN PARALLEL CIRCUIT AND A SECOND SWITCH POSITION FOR CONNECTING SAID RECORDING MEANS, SAID SECOND IMPEDANCE MEANS AND SAID AMPLIFIER MEANS IN SERIES CIRCUIT AND SAID FIRST IMPEDANCE MEANS AND SAID AMPLIFIER MEANS IN PARALLEL CIRCUIT, SAID FIRST AND SECOND SWITCH POSITION OF SAID SWITCHING MEANS BEING MUTUALLY EXCLUSIVE.
Claim 2
Independent Claim
127 words
A SYSTEM FOR RECORDING AND PLAYING BACK ANALOG SIGNALS COMPRISING, A FIRST IMPEDANCE MEANS A SECOND IMPEDANCE MEANS, AN AMPLIFIER MEANS, A RECORDING MEANS, AND A SWITCHING MEANS CONNECTED TO SAID FIRST IMPEDANCE MEANS, SAID SECOND IMPEDANCE MEANS, SAID AMPLIFIER MEANS, AND SAID RECORDING MEANS, SAID SWITCHING MEANS HAVING A FIRST SWITCH POSITION FOR CONNECTING SAID FIRST IMPEDANCE MEANS, SAID AMPLIFIER MEANS, AND SAID RECORDING MEANS IN SERIES CIRCUIT AND SAID AMPLIFIER MEANS AND SAID SECOND IMPEDANCE MEANS IN PARALLEL CIRCUIT AND A SECOND SWITCH POSITION FOR CONNECTING SAID RECORDING MEANS, SAID SECOND IMPEDANCE MEANS AND SAID AMPLIFIER MEANS IN SERIES CIRCUIT AND SAID FIRST IMPEDANCE MEANS AND SAID AMPLIFIER MEANS IN PARALLEL CIRCUIT, SAID FIRST AND SECOND SWITCH POSITION OF SAID SWITCHING MEANS BEING MUTUALLY EXCLUSIVE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-01-21 | 1972-07-22 | 1973-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-21 | 1976-07-22 | 1977-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-21 | 1980-07-22 | 1981-01-21 | $7700.00 | Window Closed / Lapsed |