Patent US3816709A successfully refreshed from Google Patents.
US3816709A
Expired / Lapsed
US
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Electronic identification and recognition system
Assignee: Individual
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Filing: 1973-05-14
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Granted: 1974-06-11
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Expires: 1993-05-14
Abstract
Abstract An electronic identification and recognition system for identifying or recognizing an object carrying an electrically passive circuit. The system comprises an active electrical signal generation network with a sensing coil for generating a magnetic field within the proximate area of said sensing coil; and an object having a passive electrical circuit with a coded resonant frequency, said object being adapted to move relative to and from said proximate area and adapted for inductive coupling with said active system. The active generation network being further adapted to generate digital control signals responsive to the resonant frequency of the passive object when said passive object is inductively coupled with said active system.
Inventors
- 👤 C Walton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:11
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/08; G06K7/082; G06K7/083; G06K7/086; B; B07; B07C; B07C3/00; B07C3/10; B07C3/12; B61; B61L; B61L25/00; B61L25/02; B61L25/04; B61L25/043
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
217 words
An electronic identification system for identifying electrically passive objects, the system comprising, in combination: a passive electrical object including a passive electrical circuit having a coded resonant frequency; and an active electrical signal generation network including a sensing coil for producing an electromagnetic field within the proximity of the coil responsive to an alternating current signal delivered to the coil; an oscillator means engaged to said sensing coil and adapted to repetitively generate alternating current signals over a select frequency range to said sensing coil, said sensing coil being movable relative to the passive electrical object and adapted for inductive coupling with the passive electrical object when said object is within the proximity of said sensing coil, detector means for detecting changes in the field characteristics of said sensing coil as the frequency of the generated field approaches the coded resonant frequency of the passive object, the detector means being adapted to generate a signal of varying amplitude representative of said field characteristics of said sensing coil, said detector means being further adapted to generate time base signals responsive to the detected resonant frequency of the passive object; and measurement means responsive to the oscillator means and the detector means for counting the cycles of the oscillator means during the time intervals of said time base signals.
Claim 2
Dependent Claim
217 words
An electronic identification system for identifying electrically passive objects, the system comprising, in combination: a passive electrical object including a passive electrical circuit having a coded resonant frequency; and an active electrical signal generation network including a sensing coil for producing an electromagnetic field within the proximity of the coil responsive to an alternating current signal delivered to the coil; an oscillator means engaged to said sensing coil and adapted to repetitively generate alternating current signals over a select frequency range to said sensing coil, said sensing coil being movable relative to the passive electrical object and adapted for inductive coupling with the passive electrical object when said object is within the proximity of said sensing coil, detector means for detecting changes in the field characteristics of said sensing coil as the frequency of the generated field approaches the coded resonant frequency of the passive object, the detector means being adapted to generate a signal of varying amplitude representative of said field characteristics of said sensing coil, said detector means being further adapted to generate time base signals responsive to the detected resonant frequency of the passive object; and measurement means responsive to the oscillator means and the detector means for counting the cycles of the oscillator means during the time intervals of said time base signals.
Claim 3
Dependent Claim
30 words
The system of claim 1 in which the active electrical signal generation network includes an isolation network to isolate the oscillator means from the electrical load on said sensing coil.
Claim 4
Dependent Claim
67 words
The system of claim 1 in which said detector means includes a first detector adapted to generate an output signal which signal assumes a positive value when the phase of the oscillator frequency value is on one side of the resonant frequency of the passive object and a negative value when the phase of the oscillator frequency value is on the other side of the resonant frequency.
Claim 5
Dependent Claim
80 words
The system of claim 3 in which said detector means further includes a second detector in the form of a crossover detector adapted to respond to the output of said first detector and a signal of a preset absolute level, said crossover detector being adapted to generate a pulse having a time duration commencing when said positive signal of said first detector exceeds said absolute level and terminating when said negative signal of said first detector exceeds said absolute value.
Claim 6
Dependent Claim
52 words
The system of claim 3 in which said detector means further includes a second detector in the form of a differentiator network adapted to respond to the output of said first detector and to generate a pulse as the output signal as said first detector passes through a zero reference voltage level.
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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |