Zoom lens system and imaging apparatus

摘要

A zoom lens system includes: a primary image forming lens group that forms light from an object side into an intermediate image and a relay lens group that forms light from the intermediate image into a final image. The primary image forming lens group includes, in order from the object side, a first fixed lens group G1 with negative refractive power, a stop St, and a second fixed lens group G2 with positive refractive power, and the relay lens group includes, in order from the object side, a third fixed lens group G3 with negative refractive power, a first moving lens group G4 with positive refractive power, and a second moving lens group G5 with positive refractive power.

主权项

1. A zoom lens system, consisting:
a first optical system that forms light from an object side into an intermediate image; and a second optical system that forms light from the intermediate image into a final image, wherein the first optical system consists of a fixed lens group that is fixed throughout an entire zoom range of the zoom lens system, the second optical system includes a variator lens group that moves during zooming, and the fixed lens group includes a first negative meniscus lens that is disposed closest to the object side and whose convex surface is oriented toward the object side, wherein the second optical system includes a third fixed lens group with negative refractive power that is disposed on the object side of the variator lens group and does not move during zooming; wherein the third fixed lens group includes a first positive meniscus lens that is disposed closest to the final image side and whose convex surface is oriented toward the final image side, and a refractive index n1 of the first negative meniscus lens and a refractive index n3 of the first positive meniscus lens satisfy following conditions
n1≧1.65n3≧1.900.82≦n1/n3<1.00.