| 摘要 |
PURPOSE:To compensate an optical path length variation without enlarging the whole machine unnecessarily by linking a transparent plate material inserted into an optical path at an angle equal to an angle formed by a luminous flux split means and an optical axis when inserting said means, to the luminous flux split means, when releasing the luminous flux split means. CONSTITUTION:When a luminous flux splitting half mirror 7 is released from an optical path to a position shown by alternate long and that dash lines, a transparent plate 50 is interlocked with the half mirror 7 and switched through a connecting rod for linking the tip of an arm 104 extending from a turning supporting point 105 of a bracket 102 for holding the half mirror 7, and the tip of an arm 54 extending from the turning center of a bracket 50 and 51 for supporting an optical path length compensating transparent plate 50 and a red filter 51, and a spring 56 provided between the tip and the machine frame, and inserted into an optical path in the direction parallel to the first direction in the optical path of the half mirror 7. In this way, the whole machine does not become large unnecessarily, and an optical path length variation is compensated. |
