| 摘要 |
PROBLEM TO BE SOLVED: To provide a portable radio device which enables a user to perform the limited number of times of authentication operations even when the device exhausts its battery.SOLUTION: The portable radio device which performs radio communication with an on-vehicle radio apparatus, comprises: a control circuit 2 which performs radio communication of predetermined signals; a primary battery 4 which supplies power to drive the control circuit 2; a backup power supply 5 which can substitute the primary battery 4 as another power supply; and switching means 6 which switches between the primary battery 4 and the backup power supply 5 for supplying power to the control circuit 2 according to predetermined operations by a user. |
