| 摘要 |
PURPOSE:To suppress the generation of chromatic beats without spoiling resolution by slanting planes arrayed alternately slanting in the opposite directions and separately from each other, and planes and curved surfaces which form mountain parts and valley parts of the adjacent slanting planes. CONSTITUTION:With regard to a filter 10 of prism structure where columnar blocks made sectionally trapezoid are arrayed, unidirectional slanting planes 11a slanting at an angle alpha in one direction and opposite-directional slanting planes 11b slanting at the angle alpha in the opposite direction are arrayed by turns and at intervals, and the mountain part of the adjacent slanting planes 11a and 11b and the valley part are shaped into a plate 11c and a plane 11d, respectively. The planes 11c and 11d cross an optical axis at right angles. Here, only the slanting planes 11a and 11b in the filter 10 exhibit light refrecting effect. |
