| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a zoom lens which has a wide angle of view, a high zoom ratio and a high optical performance over the entire zoom range. <P>SOLUTION: The zoom lens includes: in order from an object side to an image side, a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a rear group including two or more lens groups, and having a positive refractive power, wherein as the whole, the zoom lens changes the intervals of the respective lens groups in zooming. The rear group includes a lens group R having a positive refractive power on the most image side. The lens group R includes an aspherical shaped lens whose image-side surface is concave and negative refractive power gets stronger as it goes away from an optical axis. The focal length f1 of the first lens group, the focal length fR of the lens group R and the focal length fw of the entire system at a wide-angle end are each appropriately set. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
