Patent ID: 9563042
Date: 2017-02-07
CPC Classifications: G02B

Claim:
1. An optical system, consisting of, in order from the magnification side, a first lens having a positive refractive power with a convex surface on the magnification side, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, a fifth lens having a positive refractive power, and a sixth lens having a positive refractive power, wherein the following conditional expressions (1) and (2) are satisfied: where D2: distance on the optical axis between the first lens and the second lens f: focal length of the entire system νd1: Abbe number of the first lens with reference to d-line νd2: Abbe number of the second lens with reference to d-line.