| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide-angle zoom lens which easily assures a telecentric property suitable especially for a single lens reflex digital camera. SOLUTION: The wide-angle zoom lens is constituted of a negative 1st group G1, a positive 2nd group G2, and a positive 3rd group and the wide-angle zoom lens is characterized in that, in variable magnification from a wide-angle end to a telescopic end, it performs variable magnification by moving at least the 1st group G1 and the 2nd group G2 so as to decrease spacing between the 1st group G1 and the 2nd group G2 and to increase spacing between the 2nd group G2 and the 3rd group G3, and the 1st group G1 is constituted of a 1st sub-lens group SG1a of negative refracting power and a 2nd sub-lens group SG1b of negative refracting power in order from an object side, and in focusing from a long-distance object point to a short-distance object point, the 1st group G1 is extended to the object side while decreasing spacing between the 1st sub-lens group SG1a and the 2nd sub-lens group SG1b. COPYRIGHT: (C)2006,JPO&NCIPI
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