| 摘要 |
PROBLEM TO BE SOLVED: To cope with the various service circumstances of a focusing image-formation optical system, in the image-formation optical system which detects focusing by branching incident luminous flux in the image-formation optical system. SOLUTION: The focusing image-formation optical system has at least one branching optical system 2 in an optical path on an image side of a focus moving group 1, and detects a focusing state by a focusing detection means 7 by using luminous flux from the branching optical system 2. An arithmetic means 8 allows a driving means 9 to drive the focus moving group 1 based on a signal from the focusing detection means 7, thereby performing focusing operation. COPYRIGHT: (C)2007,JPO&INPIT |
