Patent ID: 8630046
Filing Date: 2014-01-14
Classification: G02B,Y10T

Abstract:
1. A lens system comprising, in order from an object, a front-side lens group having a positive refractive power and a rear-side lens group having a positive refractive power; wherein the front-side lens group comprises, in order from the object, a first lens component having a positive refractive power and a second lens component having a positive refractive power; wherein the rear-side lens group comprises a cemented lens constructed by cementing together a positive lens and a negative lens in order from the object; and wherein the lens system satisfies the following conditional expressions: where ν1 denotes an Abbe number of the first lens component at d-line, ν2 denotes an Abbe number of the second lens component at d-line, γF1 denotes an amount of movement of the front-side lens group upon focusing from infinity to a magnification of −0.01, and γR1 denotes an amount of movement of the rear side lens group upon focusing from infinity to the magnification of −0.01.