| 摘要 |
PROBLEM TO BE SOLVED: To provide an unmanned photographing device which prevents deterioration of imaging devices and reduces power consumption by detecting a mobile object at a low cost. SOLUTION: A CCD (Charge Coupled Device) image sensor 14 periodically performs exposure to obtain a picture in a photographing range by completion of one-time exposure. A measurement section 30 provides detection areas at the center part and the end part of the picture and integrates respective brightness values to measure the difference. A detection section 30 compares the difference between the brightness values with a previously set threshold to conduct detection whether or not the mobile object is present in front of a camera. When determination is made that no mobile object is present when the difference of the brightness values is below the threshold, the measurement section 30 measures the brightness value of the right end parts of the picture whose difference of the brightness values is measured and the brightness values of the right end parts of pictures immediately before and after the picture whose difference of the brightness value is measured, and the detection part compares three brightness values with each other. When no mobile object is detected by the comparison of the brightness values, a power control section 32 transmits a signal to a photographing power section 41 to repeatedly turn on and off the power of a photographing section at fixed intervals. COPYRIGHT: (C)2004,JPO |
