| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-performance zoom lens which is compact though it has a high variable power ratio such as about 8 or more, and which can restrain the occurrence of aberration. SOLUTION: A first lens group 110 is constituted by arranging a negative lens 111, a positive lens 112 and a positive lens 113 in order from an object side, and has positive refractive power as a whole. A second lens group 120 is constituted by arranging a negative lens 121, a negative lens 122, a positive lens 123 and a negative lens 124 in order from the object side, and has negative refractive power as a whole. A third lens group 130 is constituted by arranging a positive lens 131, a positive lens 132 and a negative lens 133 in order from the object side, and has positive refractive power as a whole. Both surfaces of the positive lens 131 and the surface on an image surface 160 side of the negative lens 133 are formed to be aspherical. A fourth lens group 140 is constituted by arranging a positive lens 141 and a negative lens 142 in order from the object side, and has positive refractive power as a whole. COPYRIGHT: (C)2007,JPO&INPIT
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