Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
163 words
An article-identification system, comprising an interrogator operative to produce at a particular location through which such article passes a succession of sharply pulsed interrogation signals each having essEntially the same frequency, a normally dormant identification responder for transport in association with such article through said location and including a tuned circuit having a predetermined resonant frequency different from that of such interrogation signal but responsive thereto so as to be energized thereby and produce an article-identifying signal having predetermined frequency characteristics corresponding to such resonant frequency, a sensor receptive to such identification signal and operative to establish such frequency characteristics thereof, and utilization means connected with said sensor for evidencing as a function of such established frequency characteristics the presence of said identification responder and associated article at such location, whereby a plurality of such articles respectively equipped with normally dormant identification responders having tuned circuits providing differing resonant frequencies all responsive to the same interrogation signals can be differentiated one from another.
Claim 2
Dependent Claim
163 words
An article-identification system, comprising an interrogator operative to produce at a particular location through which such article passes a succession of sharply pulsed interrogation signals each having essEntially the same frequency, a normally dormant identification responder for transport in association with such article through said location and including a tuned circuit having a predetermined resonant frequency different from that of such interrogation signal but responsive thereto so as to be energized thereby and produce an article-identifying signal having predetermined frequency characteristics corresponding to such resonant frequency, a sensor receptive to such identification signal and operative to establish such frequency characteristics thereof, and utilization means connected with said sensor for evidencing as a function of such established frequency characteristics the presence of said identification responder and associated article at such location, whereby a plurality of such articles respectively equipped with normally dormant identification responders having tuned circuits providing differing resonant frequencies all responsive to the same interrogation signals can be differentiated one from another.
Claim 3
Dependent Claim
23 words
The system of claim 1 in which said pulse generator produces interrogation signals having a pulse width of the order of 2 microseconds.
Claim 4
Dependent Claim
53 words
The system of claim 1 in which said interrogator further includes an inductance connected with said pulse generator and defining a signal-transmitting device positioned adjacent said particular location to transmit interrogation signals thereat, and in which said signal-transmitting device is tuned to the frequency of the interrogation signals produced by said pulse generator.
Claim 5
Dependent Claim
17 words
The system of claim 3 in which said inductance is a relatively large coil of low resistance.
Claim 6
Dependent Claim
20 words
The system of claim 4 in which said inductance comprises 1 turn and has a resistance of about 0.1 ohm.
Claim 7
Dependent Claim
48 words
The system of claim 3 in which said interrogator is operative to limit the voltage present across said inductance to a relatively low value and thereby limit the electric components in the signal field developed by said inductance to low values so as to minimize electromagnetic radiation therefrom.
Claim 8
Dependent Claim
40 words
The system of claim 3 in which said interrogator developes a power ratio per identification signal pulse of at least about 2 milliwatts average power per square foot of area at said predetermined location through which such article may pass.
Claim 9
Dependent Claim
38 words
The system of claim 1 in which said sensor includes a zero axis crossing detector so as to establish the frequency characteristics of any such identification signal by determining the zero axis crossings of any 1 cycle thereof.
Claim 10
Dependent Claim
37 words
The system of claim 8 in which said sensor further includes a broad-band amplifier interposed between said receiver inductance and zero axis crossing detector, and a threshhold detector coupling said broad-band amplifier and zero axis crossing detector.
Claim 11
Dependent Claim
30 words
The system of claim 9 in which said sensor further includes an interval counter for measuring the interval between the zero axis crossings determined by said zero axis crossing detector.
Claim 12
Dependent Claim
46 words
The system of claim 1 in which said utilization means includes a logic component operative to establish the count number within a finite time period representing such frequency characteristics, and in which said logic component includes a high-count-hold logic circuit and a hold-count timer connected therewith.