Resonant circuit detection measurement and deactivation system employing a numerically controlled oscillator
First Claim
1. An apparatus for deactivating a security tag in a deactivation zone comprising:
- a numerically controlled oscillator for generating a first alternating electric signal, the frequency of the first alternating electric signal varying in accordance with a numerical frequency control signal;
a clock having a substantially fixed frequency connected to the numerically controlled oscillator for providing a frequency reference to the numerically controlled oscillator, the frequency of the first alternating electric signal being restricted to an integer multiple of an integer sub-multiple of the frequency of the clock; and
a transmitting antenna connected to the numerically controlled oscillator for receiving the first alternating electric signal and establishing a first electromagnetic field within the deactivation zone wherein the first electromagnetic field interacts with the security tag to deactivate the security tag.
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Accused Products
Abstract
An apparatus for deactivating a resonant circuit without physically contacting the resonant circuit. The EAS system includes a numerically controlled oscillator for generating an alternating electric signal, the frequency of the alternating electric signal varying in accordance with a numerical frequency control signal; a clock having a substantially fixed frequency connected to the numerically controlled oscillator; and a transmitting antenna connected to the numerically controlled oscillator for establishing an electromagnetic field within a deactivation zone. The frequency of the alternating electric signal is restricted to being an integer multiple of an integer sub-multiple of the clock frequency.
67 Citations
10 Claims
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1. An apparatus for deactivating a security tag in a deactivation zone comprising:
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a numerically controlled oscillator for generating a first alternating electric signal, the frequency of the first alternating electric signal varying in accordance with a numerical frequency control signal;
a clock having a substantially fixed frequency connected to the numerically controlled oscillator for providing a frequency reference to the numerically controlled oscillator, the frequency of the first alternating electric signal being restricted to an integer multiple of an integer sub-multiple of the frequency of the clock; and
a transmitting antenna connected to the numerically controlled oscillator for receiving the first alternating electric signal and establishing a first electromagnetic field within the deactivation zone wherein the first electromagnetic field interacts with the security tag to deactivate the security tag. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification