| 摘要 |
PURPOSE:To make the depression angle range large and make operation possible at ease by arranging an image erecting means closely by a reflection optical member so that the luminous flux from the reflection optical member can be made incident. CONSTITUTION:A prism 33 consists of a D prism 33a and a depression-view prism 33b for twice reflection and has a surface S which splits the incident luminous flux at a 45 deg. and a 0 deg. angle of transmission and deflection. A Porro prism 35 is constituted into a Porro prism type 2 by using an incidence-side right-angled prism 35a, an intermediate right-angled prism 35b, and a projection- side right-angled prism 35c. This Porro prism 35 is arranged closely by the depression view prism 33b so that the luminous flux from the depression-view prism 33b can be made incident. Further, the reflecting surface (c) of the projection-side right-angled prism 35c is set to larger area than the reflecting surface (a) of the incidence-side right-angled prism 35a and the optical member from this Porro prism 35 to an ocular 38 is stored in an ocular lens barrel. |
