| 摘要 |
PROBLEM TO BE SOLVED: To photograph and regenerate a three-dimension object by providing the apex angle of an arrowhead shaped compound achromatic prism having specific circular arc on the extreme end toward the object side, and providing a slit diaphragm close to a brightness diaphragm. SOLUTION: The apex angle of an arrowhead shaped compound achromatic prism 6 of which the ridge line of the fixed apex angle is a circular arc of radius r1 computed based on a vertical field angle, and the valley side is circular arc of radius r2 is a concentric circle to the circular arc of radius r1, is provided on the extreme end toward the object side. The arrowhead shaped compound achromatic prism 6 is constituted by sticking together two prisms 30, 31. The projecting side prism 30 is crown glass, and the recessed side prism 31 is formed by using front glass. This arrowhead shaped compound achromatic prism 6 is designed so that incidental light from the front face becomes red and violet in parallel at outgoing. Further, it is designed so that dispersed rays after transmitting the projecting side prism 30 become parallel rays by the recessed side prism 31. |
