Patent ID: 7834743
Filing Date: 2010-11-16
Classification: G06K

Abstract:
1. An RFID tag that stores data, comprising: a first antenna for transmitting radio waves; a transmission means for generating a transmission signal by modulating the data, and providing the transmission signal to the first antenna; an emission control means for controlling an output power of the first antenna in order to transmit the transmission signal, the emission control means being connected to the first antenna and the transmission means; a determination means for determining a value of the output power of the first antenna; and an authentication means for authenticating an external device to which the radio waves from the first antenna are transmitted, wherein the determination means determines the value of the output power to be set high when the external device is authenticated by the authentication means, and determines the value of the output power to be set low when the external device is not authenticated by the authentication means, and the emission control means controls the output power of the first antenna based on the value determined by the determination means; and wherein the RFID tag further comprises a setting-receiving means for receiving settings of the values of the output power from the external device, and the determination means determines the value of the output power based on a setting command for the received settings of the values when the external device is authenticated by the authentication means; and a second antenna for transmitting radio waves at an output power different from the output power of the first antenna, the second antenna being connected to the transmission means via the emission control means, wherein the emission control means has a connection control means for disconnecting a connection between the first antenna and the transmission means.