Patent ID: 8279539

Claim:
A transfer lens, in order from the object side to the image side thereof, comprising: a first lens having negative refraction power; and a second lens having positive refraction power, wherein the transfer lens satisfies the following conditions: 0.4 <|f 1 /f 2|<0.8; 2 <v 1 /v 2<3.8; 0.86 <N 1 /N 2<1.12; where, f1 is a focal length of the first lens, f2 is a focal length of the second lens, v1 is an Abbe constant of the first lens, v2 is an Abbe constant of the second lens, N1 is a refractive index of the first lens, N2 is a refractive index of the second lens; wherein the transfer lens is aligned with a main lens comprising an entrance pupil plane to let in lights, the first lens comprises a first front principal point surface and a first rear principal point surface opposite to the first front principal point surface, the second lens comprises a second front principal point surface and a second rear principal point surface opposite to the second front principal point surface, and the transfer lens further satisfies the following condition: 3.1<D1/D2<3.5; wherein, D1 is a distance between a first front principal point surface of the first lens and the second front principal point surface of the second lens, D2 is a distance between the second rear front principal point surface of the second lens and the entrance pupil plane.