| 摘要 |
PURPOSE:To facilitate the focusing, by providing at a place near a focal point an optical element which is obtained by bundling plural rod lenses made of heterogeneous media with their optical axes set in parallel to each other and has both end faces of the rod lens bundle forming the planes veritcal to the optical axis. CONSTITUTION:A focal plate 2 has an in-focus detecting suface 2a and can be provdied with a matte surface, etc. An in-focus detecting lens 3 consists of a number of microlenses and set at the center of the plate 2. Each microlens 3 is equal to a heterogeneous lens, and a subject point (a) is set on the surface 2a. Then the optical axes of the microlenses are set in parallel to each other, and an incident side end face 3a and an output side end face 3b form a plane which is vertical to the optical axes. |
