| 摘要 |
A reflection/refraction optical system in which an effective stop installation portion is provided, a long-enough working distance is achieved, and as small a concave mirror as possible which is conventionally liable to be large. The system is characterized in that it includes, in the order from a first plane R toward a second plane W, a first image-forming optical system (G1) having a refracting lens, a second image-forming optical system (G2) having at least one concave lens and two reflecting mirrors, and a third image-forming optical system (G3) having a refracting lens, and in that the first image-forming optical lens (G1) forms a first intermediate image (IM1) of the first plane R, the second image-forming optical system (G2) forms a second intermediate image (IM2) by re-formation of the first intermediate image (IM2), and the third image-forming optical system (G3) re-forming the second intermediate image (IM2) on the second plane W. |
