Patent ID: 6091342
Filing Date: 2000-07-18
Classification: G06K

Abstract:
A transponder communication device for contactless communication with at least one transponder, said transponder communication device comprising:interrogation means for generating at least one item of interrogation information by means of which a transponder present within a receiving range of the transponder communication device which is in an active state is interrogatable to generate and transmit answer information;transmission means for transmitting the at least one item of interrogation information to a transponder present within the receiving range;receiving means for receiving answer information generated and transmitted by a transponder present within the receiving range in response to the at least one item of interrogation information; anddeactivation means for generating at least one item of deactivation information by means of which a transponder present within the receiving range and which is in its active state is settable to a state in which the transponder does not generate and transmit answer information in response to the at least one item of interrogation information,the deactivation means comprising a deactivation stage for generating deactivation information by means of which a transponder present within the receiving range, which transponder has already transmitted answer information in response to interrogation information in its active state, subsequently settable from its active state to a passive state, the deactivation means comprising a further deactivation stage for generating at least one item of further deactivation information by means of which a transponder present within the receiving range, which transponder has already transmitted answer information in response to interrogation information in its active state, subsequently settable from its active state to a standby state,the interrogation means comprising an interrogation stage for generating interrogation information by means of which a transponder present within the receiving range is settable from its passive state to its active state and, in addition, is interrogatable, when necessary, to again generate and transmit answer information, the interrogation means further comprising a further interrogation stage for generating further interrogation information by means of which a transponder present within the receiving range is settable from its standby state to its active state and, in addition, is interrogatable to again generate and transmit answer information, and the interrogation means still further comprising a still further interrogation stage for generating at least one item of further interrogation information by means of which a transponder within the receiving range, which transponder has already transmitted answer information in response to interrogation information in its active state, is interrogatable to again generate and transmit answer information without leaving the active state.