| 摘要 |
PURPOSE:To separate and remove reflected light and increase the angle of observation photographic view above 45 deg. by setting such curvature that light emitted from the point where a luminous flux separating means crosses the optical axis travels back in the same path with an incident light image when the light passes through the 2nd lens group and is reflected by the final surface of the 1st lens group. CONSTITUTION:The center of curvature of a surface r4 is in the center of a holed mirror 7 and the radius of curvature of a surface r2 is so determined that the light emitted from the point where the holed mirror 7 crosses the optical axis travels back in the same path with the incident light image when passing through the lens group 22 and reflected by the surface r2, thereby separating and removing surface reflected light from those surfaces from observation photographic light. Further, one more lens group 21 with positive refracting power is provided before one lens group corresponding to the conventional lens group 22 to put refracting power in partial charge, and consequently aberration compensation of the whole system is improved and the angle of observation photographic view is increased to 45 deg.. |
