Catadioptric system and image pickup apparatus

摘要

The catadioptric system includes a first imaging optical system collecting light from an object and a second imaging optical system causing the light from the first imaging optical system to form an intermediate image and to cause the light from the intermediate image to form an optical image. The first imaging optical system includes a first optical element including a first light transmissive portion and a first back reflective portion, and a second optical element including a second light transmissive portion and a second back reflective portion. The first light transmissive portion, the second back reflective portion, the first back reflective portion and the second light transmissive portion introduce the light from the object to the second imaging optical system. The second imaging optical system includes an aspheric lens having a negative refractive power on and around the optical axis and a positive refractive index in its peripheral portion.

主权项

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:
a first optical element including (a) a first light transmissive portion formed on and around an optical axis and (b) a first back reflective portion formed as an object side surface in a more outer peripheral side portion than the first light transmissive portion; anda second optical element including (c) a second light transmissive portion formed on and around the optical axis and (d) a second back reflective portion formed as an image side surface in a more outer peripheral side portion than the second light transmissive portion, 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:
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