| 摘要 |
PURPOSE:To constitute a compact optical system while shortening the length of its optical path by reflecting light for distance measurement passed once through an optical path branching glass block by a mirror surface, and passing it through said optical path branching block again. CONSTITUTION:Light passed through a lens group 1 is branched by the optical path branching glass block 2; and light for photography reaches an image pickup surface 4 through a lens system 3 and light for AF distance measurement enters an optical system 5 for aberration compensation, but the mirror surface 5 is formed as the final surface of the optical system 5 for aberration compensation. Therefore, the light for distance measurement entering the optical system 5 is reflected by this mirror surface 5a to reach a sensor 6 for distance measurement through the optical system 5 for aberration compensation and optical path demultiplexing glass block 2. Thus, the optical path length of the optical system for distance measurement is shortened, so the optical system for distance measurement is constituted compactly. |
