| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable power optical system high in performance, small in size and high in variable power ratio, and to provide an imaging apparatus equipped with the variable power optical system. SOLUTION: This system is composed of: includes, a first lens group G1 having positive power; a second lens group G2 having negative power; a third lens group G3 having positive power; and a fourth lens group G4 having positive power in this order from an object side, and the power is varied by moving at least the first lens group G1 and the third lens group G3. A bending means (prism PR) for bending an optical axis AX is arranged between the second lens group G2 and the third lens group G3, and the following conditional inequalities are satisfied; 0.2<ϕ3/ϕW<1.0, 1.5<ϕ3/ϕT<10.0, and -2.0<M4/M3<2.0 (ϕ3 is power of G3,ϕW: power of the whole system at wide angle end (W),ϕT is power of the whole system at telephoto end (T), M3 is relative moving extent of G3 in the case of varying power from the wide angle end (W) to the telephoto end (T) (positive is established in the case of moving to the object side), M4: relative moving extent of G4 in the case of varying the power from the wide angle end (W) to the telephoto end (T) (positive is established in the case of moving to the object side)). COPYRIGHT: (C)2007,JPO&INPIT |
