Patent ID: 8149091

Claim:
A radio-frequency tag communication device arranged to transmit a transmitted signal toward a radio-frequency tag, and to receive a reply signal transmitted from the radio-frequency tag in response to the transmitted signal, for communication with the radio-frequency tag, said radio-frequency tag communication device comprising: a transmission control portion operable to control transmission of said transmitted signal, so as to prevent overlapping of an area of communication of said radio-frequency tag communication device and an area of transmission of another radio-frequency tag communication device; and a radio-frequency-tag communication judging portion operable to determine whether there is any radio-frequency tag which exists within said area of communication of said radio-frequency tag communication device and which is under communication with said another radio-frequency tag communication device, and wherein said transmission control portion restricts the transmission of the transmitted signal when an affirmative determination is obtained by said radio-frequency-tag communication judging portion.