| 摘要 |
PURPOSE:To surely discriminate a lens moving direction for focusing and moving quantity and to prevent useless lens drive by combining a fundamental equation of a lens and a contour extracted value to a picture memory and taking notice of the presence of correlation. CONSTITUTION:An analog video signal outputted from an image pickup element 2 is converted into a 6-bit digital video signal by an A/D converter 3 and stored in a picture memory 4. A block data from the picture memory 4 based on the address is extracted by a microcomputer 5 and stored in a work RAM 6 and an address of the picture memory 4 is stored in the work RAM 6. The picture memory 4 corresponds to a TV monitor screen on which the pickup data is displayed and also corresponds to the picked-up image on the image pickup element 2. Thus, the video signal in the picture memory 4 has correlation with respect to the distance from an object in a video camera observed through the lens 1. Thus, the distance from the center point and each ring in the picture memory 4 is selected at an equal interval, the movement for focusing the lens 1 is estimated. |
