Patent ID: 8897736

Claim:
A mobile communication terminal device comprising: a noncontact proximity communication unit carrying out noncontact proximity communication; a wireless communication unit carrying out wireless communication longer in communication distance than the noncontact proximity communication and input/output control for the wireless communication; a security controller utilized in security processing for the noncontact proximity communication unit and the wireless communication unit; and a battery, wherein the noncontact proximity communication unit receives both electromagnetic field power from a carrier in noncontact proximity communication and battery power from the battery, wherein the noncontact proximity communication unit supplies, as an operating supply power to the security controller, one of the electromagnetic field power and the battery power which is selected depending upon a voltage of the battery, wherein the security controller determines whether or not voltage from power supplied from the noncontact proximity communication unit has reached a specified level and, when it is determined that the specified level has not been reached, carries out control so as to reduce the electricity consumption of the security controller, wherein when the battery voltage is higher than a predetermined voltage, the noncontact proximity communication unit supplies the electromagnetic field power as the operating supply power to the security controller if the electromagnetic field power is produced, and supplies the battery power as the operating supply power to the security controller if the electromagnetic field power is not produced, and wherein when battery voltage is lower than the predetermined voltage, the noncontact proximity communication unit supplies the electromagnetic field power as the operating supply power to the security controller if the electromagnetic field power is produced, and interrupts the supply of the battery power to the security controller.