Pulsed electronic article surveillance device employing expert system techniques for dynamic optimization
First Claim
1. In combination, in an electrical article surveillance system:
- (a) a plurality of receiving coils; and
(b) noise environment analysis means for determining the noise environment individual to each of said receiving coils.
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Accused Products
Abstract
An electronic article surveillance system has a receiver with a plurality of receiving coils. Each coil in the system is treated as a separate detection unit with its own noise environment which is distinct from the noise environments of the other coils in the system. This allows the system to optimize its performance by maximizing the sensitivity of each coil according to its own local noise environment. In EAS systems in accordance with the invention, the priority of the detection routines is to keep an accurate and up-to-date picture of the noise environment for each coil in "noise phases" and to look for tags during "transmit phases". Upon tag detection, a controller establishes a validation sequence comprising a number of cycles and can change the number of cycles adaptively to the noise environment.
39 Citations
60 Claims
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1. In combination, in an electrical article surveillance system:
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(a) a plurality of receiving coils; and (b) noise environment analysis means for determining the noise environment individual to each of said receiving coils. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An electronic article surveillance system, comprising:
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(a) transmitter means operable for generating a magnetic field in a surveillance area; and (b) a receiver having a plurality of receiving coils and noise environment analysis means operable for determining the noise environment individual to each of said receiving coils. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. An electronic article surveillance system, comprising:
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(a) transmitter means operable for generating a magnetic field in a surveillance area; (b) a receiver having a plurality of receiving coils and operable, upon detection of an electronic article surveillance tag, to implement a validation sequence on a succession of signals received by the receiving coil which provided the signal giving rise to said detection; and (c) control means for operating said transmitter means and said receiver means, said control means having facility for varying the number of cycles in said validation sequence. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. An electronic article surveillance system, comprising:
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(a) transmitter means operable at a fundamental frequency for generating a magnetic field in a surveillance area; (b) a receiver for detection of electronic article surveillance tags; and (c) control means for operating said transmitter means with a frequency hopping between frequencies respective above and below said fundamental frequency. - View Dependent Claims (54)
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55. An electronic article surveillance system, comprising:
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(a) transmitter means operable for generating a magnetic field in a surveillance area; (b) a receiver having a plurality of receiving coils and operable, upon detection of an electronic article surveillance tag, to implement a validation sequence on a succession of signals received by the receiving coil which provided the signal giving rise to said detection; and (c) control means for operating said transmitter means in one cycle of said validation sequence to transmit energy at a frequency at which a deactivated electronic article surveillance tag is resonant.
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56. An electronic article surveillance system, comprising:
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(a) transmitter means operable for generating a magnetic field in a surveillance area; (b) a receiver having noise environment analysis means and operable, upon detection of an electronic article surveillance tag, to implement a validation sequence on a succession of signals received thereby; and (c) control means for establishing the number of cycles in said validation sequence adaptively to the noise environment determined by said noise environment analysis means. - View Dependent Claims (57, 58, 59, 60)
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Specification