Patent ID: 6942158
Filing Date: 2005-09-13
Classification: G06K,H04B

Abstract:
1. A memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a reader signal from a reader, the magnitude of the output signal being dependent on the magnitude of the reader signal, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal which is configured to cause the reader to increase the magnitude of the reader signal from a first level to a second relatively high level, and when the magnitude of the output signal is relatively high as a result of the tag receiving the second relatively high magnitude reader signal from the reader, the detector module is operable to cause the tag to move to an operating mode.