| 摘要 |
The invention relates to an image-formation optical system that satisfies demands toward high performance and compactness at the same time, and an imaging system incorporating the same. The image-formation optical system comprises, in order from its object side, an aperture stop S, a first positive meniscus lens L1 convex on its object side, a second positive lens L2 having an aspheric surface and a third negative lens L3 having an aspheric surface, and satisfies the following condition. <?in-line-formulae description="In-line Formulae" end="lead"?> 0.95<Sigmad/f< 1.25 (1)<?in-line-formulae description="In-line Formulae" end="tail"?> Here Sigmad is the distance on an optical axis of the image-formation optical system from the object side-surface of the first positive meniscus lens to the image plane side-surface of the third negative lens, and f is the focal length of the image-formation optical system.
|
