Detecting circuit and method for detecting power interruption in a camera

摘要

A camera powered by a battery has a first memory area for storing first data used in operating the camera and for retaining the first data irrespective of a power source interruption in the camera, and a second memory area powered by the battery for storing second data which is dependent upon the first data. A power interruption in the camera, such as occurs when the battery is exhausted or replaced, is detected by comparing the first data stored in the first memory area with the second data stored in the second memory area. After detection of a power interruption, the camera is initialized and the first data stored in the first memory area is then copied into the second memory area. Since the first memory area and the second memory area are compared each time the camera is activated, the state of the battery can be reliably checked.