| 摘要 |
PROBLEM TO BE SOLVED: To suppress the directional variation in a light beam emitted from an anamorphic prism even when the anamorphic prism is moved due to the variation in the environment or a secular change. SOLUTION: A prism 4 having an incident face A to which the light beam from a light source 1 is made incident, even number of reflective faces C and D on which the light beam made incident from the incident face A is successively reflected in the prism and emitting face E from which the light beam reflected on the reflective faces C and D is emitted toward an objective lens 7 is arranged on the optical path extending from the light source 1 to the objective lens 7. |
