| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable-focal-length lens system which attains stable optical quality by reducing influence of an assembly error in manufacture, and to provide an imaging apparatus that uses the lens system. SOLUTION: The variable-focal-length lens system 1 includes, in order from an object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power. When a lens position changes from a wide angle end to a telephoto end, at least the first lens group and the second lens group move. The second lens group moves towards the object side so as to narrow a space between the first lens group and the second lens group, and an aperture diaphragm S is disposed between the first lens group and the second lens group. The second lens group includes a cemented lens component L21 composed of a positive lens whose convex face is directed to the object side and a negative lens whose concave face is directed to the image side, and a positive lens component L22 which is disposed on the image side of the cemented lens component L21 with an air space left between them and whose convex face is directed to the object side. The second lens group satisfies prescribed conditional expressions. COPYRIGHT: (C)2009,JPO&INPIT
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