| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital camera that can extend the battery lifetime under an optimum operating mode by sequentially shifting operating modes with a low consumed current to operating modes with a high consumed current so as to confirm a state of the battery on each occasion thereby sequentially selecting a mode with a high consumed current. SOLUTION: When a power switch is closed, a CPU changes from a pause mode to a start mode. Then a setting operating mode and a measured voltage are set to setting 1 and each unit is sequentially in operation. First only the CPU is operated, and an analog/digital converter in a controller is used to measure a battery voltage. When the voltage is lower than the setting voltage 1, a display means displays battery end to restore the CPU to the pause mode and the end processing is conducted. When the voltage is higher than the setting voltage 1, the CPU clock is set to a lower frequency and the CPU is started. Similarly, a TG clock is set to a low frequency, the motor operating power is set to a low power operation, an LCD backlight is set to the low power consumption operating state, and the front end is set to the low power consumption operation sequentially. If each operation is proceeded and no problem is arisen, the setting mode and the measurement voltage are brought into setting 2. COPYRIGHT: (C)2003,JPO |
