| 摘要 |
PROBLEM TO BE SOLVED: To drastically reduce adverse influence by a ghost image on an image- forming surface by making a zoom lens consisting of four lens groups having positive, negative, negative and positive refractive power in order from an object side satisfy a specified conditional expression. SOLUTION: This zoom lens is constituted of a 1st lens group G1 having positive refractive power, a 2nd lens group G2 having negative refractive power, a 3rd lens group G3 having negative refractive power, and a 4th lens group G4 having positive refractive power in order from the object side. Then, it satisfies the conditional expression|1/ΔX2|<0.1. Provided thatΔXZ: a value regulated byΔXZ=LZ-RG2L+DZ, LZ: a distance from the surface apex of the surface of the 3rd lens group G3 nearest to the object side to a conjugate point with the image-forming point of a zoom lens entire system in a synthetic optical system G3.4 from the 3rd lens group G3 to the 4th lens group G4, RG2L: the radius of curvature of the surface of the 2nd lens group G2 nearest to the image-forming surface side and DZ: a distance between the 2nd and the 3rd lens groups G2 and G3.
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