| 摘要 |
PURPOSE:To make luminous flux from a subject incident to respective photodetecting elements uniformly and to improve focusing detection precision by arranging generating means for lateral shifting images and photodetecting elements on a circumference having its center on the optical axis of an optical image formation system. CONSTITUTION:When this focusing detector is applied to a single-lens reflex camera, luminous flux passed through a photographic lens 11 is split into two by a half-mirror 18 almost at the center part of a quick return mirror 17. Luminous flux reflected by the half-mirror 18 is guided to a viewfinder system and transmitted light is guided to stripe masks 12 as lateral-shifting-image generating means and a photodetecting element array 13 which are arranged on the circumference which has the center on the optical axis of the photographic lens 11. Consequently, the distance from the optical axis to each photodetecting element is equalized and luminous flux from the subject is made incident to each photodetecting element uniformly to perform accurate focusing detection. |
