| 摘要 |
PURPOSE:To give a contrast to an object to be photographed extending over a wide distance range by arranging stepwise plural pattern surfaces against a projection lens. CONSTITUTION:A projection lens 4 is arranged so that its optical axes l1, l2 are inclined against optical axes L1, L2 of a photographic lens 1, and both the axes are intersected at a position C1 of an object to be photographed side. Also, a pattern part 5 has three pattern surfaces 5a, 5b and 5c being roughly vertical to the optical axes l1, l2 of the projection lens 4, and formed stepwise against the projection lens 4. By a light beam emitted from a light source, pattern image surfaces 5a'-5c' being conjugate to each pattern surface 5a-5c are formed on the object. The center points of each pattern surface are positioned on a segment 7, therefore, conjugate points to these center points are formed on the optical axes L1, L2. In such a way, the contrast can be given to the object extending over a wide object distance range. |
