| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable reception of an emergency alarm, even if the power of a battery is consumed. <P>SOLUTION: A remaining-quantity detector 44 detects the remaining quantity of the battery 42 from the output voltage and the consumption current of the battery 42, and informs the detected remaining quantity to a controller 22. If the remaining quantity of the battery 42 decreases up to a quantity, to a degree of being left unconsumed for reception and display of emergency alarms, the controller 22 directs a power supply controller 46 to supply power only to a demodulator 14 and an emergency alarm signal detector 30. In this condition, the signal detector 30 is on standby for the reception of emergency alarm. When the signal detector 30 detects an emergency alarm signal from the output of the demodulator 14, the controller directs the supply controller 46 to supply power to an image display controller 26 and an image display device 28, and supplies the contents of the alarm to the display controller 26; when the display controller 26 is presumed to have gone into an operating state. <P>COPYRIGHT: (C)2007,JPO&INPIT |
