AUTOMATIC FOCUSSING DEVICE CONTROLLED BY TREND OF VARIATION AND DEGREE OF RELIABILITY OF A FOCUSSING EVALUATION VALVE SIGNAL

摘要

An automatic focusing device of the present invention includes a lens group (2) by which movement a focused field of an object (30) changes, a drive motor (6) for moving the lens group, a luminance processing circuit (10) for image-sensing the object through the lens group to extract a luminance signal, an accumulating circuit (23) for outputting a focusing evaluation value signal for evaluating a focal condition of the object on the basis of the extracted luminance signal, an LSC circuit (22) for determining reliability of the outputted focusing evaluation value signal, and a control circuit (21) for controlling the drive motor (6) to improve the focal condition of the object (30) on the basis of the determined reliability. IMAGE