Patent ID: 9110287
Filing Date: 2015-08-18
Classification: G02B

Abstract:
1. A catadioptric system comprising: a first imaging optical system configured to collect a light flux from an object to form an intermediate image of the object; and a second imaging optical system configured to cause the light flux from the intermediate image to form an optical image, wherein the first imaging optical system comprises: wherein the light flux from the object enters the second imaging optical system successively through the first light transmissive portion, the second back reflective portion, the first back reflective portion and the second light transmissive portion, wherein the second imaging optical system includes an aspheric lens surface having an inflexion point at which a direction of a curvature thereof changes, and wherein the following condition is satisfied: where D represents a distance from an optical axis to an outermost off-axis principal ray in the aspheric lens surface and Ymax represents a highest image height on an image plane.