| 摘要 |
PURPOSE:To form an image with small various aberrations by allowing a hyperboloidic reflective and refractive type optical system which has a reduction lens system behind a hyperboloidic concave main reflecting mirror to meet specific requirements. CONSTITUTION:The optical system is constituted by arranging the hyperboloidic concave main reflecting mirror 1 and reduction lens system S behind it, and an image from the main reflecting mirror 1 is reduced and corrected to be formed. This optical system consists of elements R1-R9, d1-d8, N2-N5, and nu2-nu5, and (e) satisfying conditional expressions, wherein Ri and di are radii of curvature of optical surfaces and surface gaps, Ndi and nui are the refractive indexes of glass and Abbe numbers, and (e) is the eccentricity of the hyperboloidic reflecting mirror. |
