| 摘要 |
PROBLEM TO BE SOLVED: To surely focus a target collimation object by executing focusing operation by regarding respective object distances in two focusing areas as effective in the case of satisfying a specified condition based on the focusing result by a multipoint focusing means. SOLUTION: A focus detection system 20 is provided with a preamplifier 22, an arithmetic control circuit 23, a RAM 24 and an AF motor driving circuit 25, and a focusing lens driving system 30 is provided with an AF motor 31, a clutch incorporated deceleration mechanism 32 and an encoder 33. The focusing area in the observation field of a collimating telescope is divided into three or more different focusing areas, where the focusing is executed respectively. The focusing operation is executed by regarding the 1st object distance as effective in the case of judging that the respective object distances (1st object distance) in the two focusing areas separated from each other nearly the same as each other, and the object distance (2nd object distance) in any one focusing area put between the two focusing areas is almost twice as long as the 1st object distance based on the focusing result. |
