| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact, highly variable power zoom lens in which various aberrations are satisfactorily corrected from a visible region to a near-infrared region in each variable power area. SOLUTION: The zoom lens includes, in order from the object side: a first group 10 with negative refractive power; a diaphragm St; and a second group 20 with positive refractive power. When varying power from its wide angle end to its telephoto end, the zoom lens moves the second group 20 along its optical axis in the object direction. The zoom lens corrects an image face resulting from the varying of power, by moving the first group 10 along the optical axis. The first group 10 is composed of four groups consisting of four lenses, which are, in order from the object side, three single lenses L11, 12, and 13 with negative refractive power and one single lens 14 with positive refractive power. In the positive single lens L14, its object-side face is convex and the absolute value of the curvature radius of the object-side face is smaller than that of an image-side face. COPYRIGHT: (C)2008,JPO&INPIT
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