Patent ID: 6097278
Filing Date: 2000-08-01
Classification: G06K

Abstract:
A transponder communication device for providing contactless communication with a plurality of individually selectable transponders,includingtransponder selection means for the successive individual selection of transponders present within a receiving range of the transponder communication device and which are each in an active state,interrogation means, included in the transponder selection means, for generating at least one item of interrogation information by means of which transponders present within the receiving range and which are each in their active state are interrogated to generate and transmit answer information,transmission means for transmitting the at least one item of interrogation information to transponders present within the receiving range,receiving means for receiving answer information generated and transmitted by transponders present within the receiving range in response to the at least one item of interrogation information, anddeactivation means, included in the transponder selection 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, upon its selection, is set 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,characterized in thatthe transponder selection means include time-window generating means for automatically generating a series of K successive time windows,control means for the time-window generating means have been provided, by which control means the time-window generating means are controlled and activated to generate the series of K time windows automatically a plurality of times in succession,the receiving means receives at least one item of answer information in at least one time window during each series of K time windows, andthe transponder selection means include evaluation means which cooperate with the time-window generating means and the receiving means, by which a transponder is selected in dependence upon the occurrence of at least one received item of answer information in at least one time window in each series of the series of K time windows generated a plurality of times in succession.