US3230457A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital demodulator for frequencyshift keyed signals
Assignee: AT&T Inc
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Filing: 1961-09-25
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Granted: 1966-01-18
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Expires: 1981-09-25
Abstract
No abstract record available.
Inventors
- 👤 Robert O Soffel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:13
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/10; H04L27/14; H04L27/156; H04L27/1563
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
50 words
A DIGITAL DEMODULATOR COMPRISING MEANS RECEIVING FREQUENCY-SHIFT SIGNALS INCLUDING ALTERNATING -CURRENT WAVES AT DIFFERENT FREQUENCIES REPRESENTING DIFFERENT DATA BITS, MEANS GENERATING CONTROL PULSES IN RESPONSE TO ZEROVOLTAGE WAVE TRANSITIONS OF SAID ALTERNATING-CURRENT WAVES, A CIRCUIT MEASURING DURATIONS OF TIME INTERVALS BETWEEN SAID CONTROL PULSES, AND LOGIC CIRCUITS CONNECTED TO SAID
Claim 2
Dependent Claim
50 words
A DIGITAL DEMODULATOR COMPRISING MEANS RECEIVING FREQUENCY-SHIFT SIGNALS INCLUDING ALTERNATING -CURRENT WAVES AT DIFFERENT FREQUENCIES REPRESENTING DIFFERENT DATA BITS, MEANS GENERATING CONTROL PULSES IN RESPONSE TO ZEROVOLTAGE WAVE TRANSITIONS OF SAID ALTERNATING-CURRENT WAVES, A CIRCUIT MEASURING DURATIONS OF TIME INTERVALS BETWEEN SAID CONTROL PULSES, AND LOGIC CIRCUITS CONNECTED TO SAID
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) | 1969-01-17 | 1969-07-19 | 1970-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-17 | 1973-07-19 | 1974-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-17 | 1977-07-19 | 1978-01-18 | $7700.00 | Window Closed / Lapsed |