| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens having an entire lens system of compact size, wide viewing, and a high zoom ratio, which achieves high optical performance in the entire zooming range. <P>SOLUTION: An imaging apparatus has a solid state image sensor which receives an image formed by a zoom lens. The zoom lens includes a first, a second, and a third lens group having a negative, a positive, and a positive refractive power, respectively, in this order from an object side to an image side. Each of the lens groups moves during zooming. The first lens group L1 includes a negative lens G11 and a positive lens G12 in this order from the object side to the image side. The second lens group L2 includes a positive lens G21, a cemented lens composed of a positive lens G22 and a negative lens G23, and a positive lens G24, in this order from the object side to the image side. Curvature radius R23r of the lens surface of a 23rd lens adjacent to the image, refractive index n23 of the material of the 23rd lens, focal distances fw and ft of the entire system at a wide angle end and a telephoto end, and F number Fnow and half image viewing angle ωW (degree) at the wide angle end are suitably configured, respectively. <P>COPYRIGHT: (C)2012,JPO&INPIT |
