Patent ID: 8081253
Filing Date: 2011-12-20
Classification: G02B

Abstract:
1. A zoom lens comprising: an object side lens unit having a negative refracting power disposed closest to the object side, an image side lens unit having a positive refracting power disposed closest to the image side, an intermediate lens unit having a positive refracting power disposed between the object side lens unit and the image side lens unit, and an aperture stop disposed closer to the image side than the object side lens unit and closer to the object side than the image side lens unit, wherein a distance between the object side lens unit and the intermediate lens unit is smaller at the telephoto end than at the wide angle end, a distance between the intermediate lens unit and the image side lens unit is larger at the telephoto end than at the wide angle end, the intermediate lens unit moves in such a way that it is located closer to the object side at the telephoto end than at the wide angle end, the image side lens unit moves in such a way that it is located closer to the image side at the telephoto end than at the wide angle end, the aperture stop moves integrally with the intermediate lens unit during zooming from the wide angle end to the telephoto end, and a lens component is defined as a lens member whose lens surfaces that are in contact with air include only two surfaces, one being an object side lens surface and the other being an image side lens surface, the image side lens unit comprises, in order from the object side, a front lens component and a rear lens component having a positive refracting power, the front lens component has a meniscus shape with a concave object side lens surface and a convex image side lens surface, the rear lens component has a meniscus shape with a concave object side lens surface and a convex image side lens surface, the total number of lens components included in the image side lens unit is two, and the absolute value of a paraxial radius of curvature of the convex image side lens surface of the front lens component is smaller than the absolute value of a paraxial radius of curvature of the concave object side lens surface of the rear lens component.