| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a four-group zoom lens that has a small number of constituting lenses and is advantageous for downsizing in a collapsed state and also for securing a viewing angle and a variable power ratio. <P>SOLUTION: The zoom lens has, in order from an object side to an image side, a first positive lens group, a second negative lens group, a third positive lens group, and a fourth positive lens group. The first lens group comprises three lenses consisting of two positive lenses and one negative lens, the second lens group comprises three lenses consisting of two negative lenses and one positive lens, the third lens group comprises two lenses consisting of one positive lens and one positive lens in order from the object side, and the fourth lens group comprises one positive lens. The first lens group is positioned closer to the image side at the wide angle end than at the telephoto end. A positive lens in the third lens group is a positive lens convex to the object side, a negative lens in the third lens group is a negative lens concave to the image side, and a conditional expression (1) is satisfied: -1.00<f3G/f3GN<-0.1 (1). <P>COPYRIGHT: (C)2012,JPO&INPIT |
