| 摘要 |
PROBLEM TO BE SOLVED: To provide a high variable power zoom lens system having a short total lens length and a small effective diameter of the first lens group while securing superb optical performance. SOLUTION: The system is composed of, in order from the object side, the first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. The first lens group G1 is composed of, in order from the object side, a negative meniscus lens L1 having a convex surface facing the object, a first positive lens L2 having a convex surface facing the object, and a second positive lens L3. All groups move along the optical axis upon zooming from a wide-angle end W to a telephoto end T, and given conditions are satisfied. COPYRIGHT: (C)2007,JPO&INPIT
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