| 摘要 |
PURPOSE:To make a device small at a fast speed with high focusing accuracy by implementing focusing at first with a focusing means of the autocorrelation system and implementing focusing with a hill climbing focusing means. CONSTITUTION:An aperture 3 is made up of a zone 3-a having two openings at least with different sizes against a luminous flux led from an image pickup lens 1 and leading an object image onto a face of a photoelectric conversion element 3 as two images, a zone 3-b having one circular opening having a larger area around the optical axis, leading the object image to a face of the photoelectric conversion element 2 as one image, and a zone 3-c having a smaller opening. At first the zone 3-a of the aperture 3 is inserted in the luminous flux of the image pickup lens 1 and a focus lens 1-a is driven to focus the object image onto the face of the photoelectric conversion element 2 by the autocorrelation system. Then the zone 3-b or 3-c of the aperture 3 is selected and the focus lens 1-a is driven up to a position focusing the object image onto the face of the photoelectric conversion element 2 by the focusing means adopting the hill climbing system. |
