| 摘要 |
PURPOSE:To prolong the service life after actual use by making a decision whether the number of detected times of power interruption is lower than a predetermined times and operating a display drive means thereby saving a backup power supply. CONSTITUTION:When a decision is made that a power interruption sensor 9 has detected power interruption of an AC commercial power supply, a power interruption time counter is incremented (+1). A decision is then made whether the count of power interruption counter is lower than a predetermined value after reset, i.e., whether it is the first time power interruption. If it is the first time power interruption, a decision is made whether the counting operation is progressing, i.e., the current time has been set and a timer circuit 7 is counting the time. If the timer circuit 7 is counting the time, a display section 11 is controlled through a display drive section 12 while sustaining the operation of the timer circuit 7 and the display of current time or the like on the display section 11 is turned OFF. |
