Patent ID: 9671586
Date: 2017-06-06
CPC Classifications: G02B,Y10T

Claim:
1. An optical system comprising, in order from an object: a first lens group having positive refractive power; an aperture stop; and a second lens group, the first lens group including, in order from the object, a negative lens component, a positive lens component, and a first lens component, the image side surface of the first lens component being a concave surface facing the aperture stop and being a closest surface of the first lens group to the aperture stop, the second lens group including, in order from the object, a second lens component, and a positive lens component disposed closest to the image, the object side surface of the second lens component being a concave surface facing the aperture stop and being a closest surface of the second lens group to the aperture stop, and the following conditional expressions being satisfied: where fG1 denotes a focal length of the first lens group, f denotes a focal length of the optical system, TL denotes a distance, on the optical axis, from the optical surface closest to the object to the optical surface closest to the image in the optical system, and β2R denotes an imaging magnification of the positive lens component that is disposed closest to the image in the second lens group.