PAID COMMODITY DETERMINATION METHOD, PAID COMMODITY DETERMINATION SYSTEM, SETTLEMENT DEVICE THEREOF AND DETERMINATION DEVICE

摘要

To allow for detecting an unauthorized behavior such as customers' shoplifting in stores.SOLUTION: A commodity settlement device 20 acquires a commodity identification code from a commodity RFID of each commodity purchased by a customer, and after settlement processing based on this, the commodity identification code of each settled commodity is written in a settlement RFID tag as a settled commodity identification information group. The settlement RFID tag is handed over to the customer and is made to be possessed by the customer at least until he or she goes out of a store. When the customer passes through an anti-shoplifting gate-type reader antenna 2, the commodity identification code is acquired from the commodity RFID of each possessed commodity, and the settled commodity identification information group is acquired from the settlement RFID tag to determine whether or not an unauthorized behavior is present on the basis of the acquired data.SELECTED DRAWING: Figure 1