| 摘要 |
PROBLEM TO BE SOLVED: To obtain a variable focusing lens system which is small in size and suitably made large in variable power. SOLUTION: This lens system has a 1st positive lens group G1, a 2nd positive lens group G2, and a 3rd negative lens group G3 in the order from the object side and the lens position state is changed from the wide-angle end state to the telephoto end state, by moving the respective lens groups toward the object side, so that the interval between the 1st lens group G1 and 2nd lens group G2 increases and the interval between the 2nd lens group G2 and 3rd lens group G3 decreases. Then an aperture stop is arranged between the 1st lens group G1 and 3rd lens group G3, and 2nd lens group G2 has a positive lens which is arranged adjacent to the aperture stop S and has aspherical lens surfaces as both its lens surfaces and meets prescribed conditions.
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