| 摘要 |
In a camera having an LCD and a clock device, a power source consists of a battery and a booster circuit. When a power switch button is pressed, the camera moves to an ON mode including a drive mode and a standby mode. In the drive mode, the booster circuit is continuously turned on to supply voltage of a predetermined high level. In the standby mode, the booster circuit is intermittently turned on to output voltage of between the predetermined high level and a minimum display voltage level that is necessary for the LCD to keep its display density in a proper range. The booster circuit is normally turned off in an OFF mode. But if the battery voltage goes below a reset level below which a clock device of the camera cannot work, the booster circuit is intermittently turned on in the OFF mode, to boost the battery voltage up above the reset level and drive the clock device by the output voltage of the booster circuit.
|
