| 摘要 |
PURPOSE:To realize high-speed focusing operation in the case the depth of field is deep by judging the depth of field only according to a video signal without using lens position information and iris information and deciding that focusing is attained when a specified condition is satisfied in an automatic focusing device in which the high frequency component of the video signal is extracted so as to perform focusing control based on the extracted component. CONSTITUTION:A signal processing circuit 4 processes an electrical signal transmitted from an image pickup system consisting of a lens system, a diaphragm and a CCD and transmits a luminance signal to a high-pass filter 5, then a signal obtained by A/D converting the extracted high frequency component is inputted in a computing element 8. The computing element 8 arithmetically processes a digital signal from an A/D converter 7 while gating is performed by a gate circuit 9. In the case an effective peak value does not exsit, a CPU 10 obtains the data on the high frequency component concerning all the area in a lens driving range, and brings a lens to the center part of lens driving by judging that the depth of field covers all the area in the lens driving range in the case the minimum value and the tilt of the data are in a specified area. |
