| 摘要 |
PURPOSE:To prevent the consumption of a battery built in a portable radio equipment by stopping power supply to at least one notice function provided on the portable radio equipment when disconnection between the portable radio equipment and an on-vehicle main body is detected. CONSTITUTION:When a voltage detection circuit 130 detects the disconnection between a portable radio equipment 100 and an on-vehicle main body 200, the result is informed to a CPU in an audio/control section 106. When the CPU recognizes the disconnection between the portable radio equipment and the on-vehicle main body 200, the CPU issues an instruction to a display control section 120 to stop the power supply to a display driver 118b and a back light unit 118c. Thus, the switches 118d, 118e are opened and the power supply to the display driver 118b and the back light unit 118c is stopped. Thus, when the portable radio equipment is used independently, the consumption of a charged battery 110 built in the portable radio equipment is prevented. |
