| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact and inexpensive zoom lens system which has such a sufficient angle of view as≥75°and whose variable power ratio is about 3 even in a camera using a compact imaging element, and which is a zoom lens system including two lens groups, that is, a negative lens group and a positive lens group in order from an object side. SOLUTION: In the zoom lens system, the 1st lens group has at least two negative lenses and two positive lenses. The zoom lens system satisfies following conditional expressions (1) to (3). (1) 1.5<¾f1/fw¾<1.8, (2) 1.0<f2/(fw×ft)<SP>1/2</SP><1.3 and (3) 1.0<¾f2/f1¾<1.2, provided that f1: the focal distance of the 1st lens group, f2: the focal distance of the 2nd lens group, fw: the focal distance of the entire system at a short focal distance end, and ft: the focal distance of the entire system at a long focal distance end. COPYRIGHT: (C)2006,JPO&NCIPI
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