PURPOSE: An interrogating device having an extensive communicable range without interference of an electric wave.
CONSTITUTION: Frequency and/or transmission time of a transmission wave transmitted by a plural number of interrogators 3 are/is varied from each other in order not to overlap them/it. Consequently, there is no interference of electric waves among the interrogators 3 approaching others, and a communicable range with an electronic tag substantially extends. Accordingly, it comes to be possible to communicate with the electronic tag 5 attached to a load W in spite of irregularity of the size and the direction of the load W placed on a conveyor C, for example. Otherwise, the communicable range is substantially extended by moving the interrogators 3 around the conveyor C. Thereby, it is made possible to communicate with the electronic tag 5 attached to the load W in spite of irregularity of the size and the direction of the load W.
MIZUNO TOMOAKI
MATSUMOTO MANABU
