| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens, which is compact, holds satisfactory optical performance, and also reduces cost. SOLUTION: The zoom lens includes, in order from an object side, a first positive lens group G1, a second negative lens group G2 which moves to perform variable power, a diaphragm, a third positive lens group G3, and a fourth positive lens group G4 which performs correction of an image surface position associated with the variable power and focusing. The second lens group G2 includes at least two negative lenses. A plastic aspherical lens is disposed nearest to an image side in the second lens group G2. When a focal length of the plastic aspherical lens is defined as f2a and a focal length of the second lens group G2 is defined as f2, they satisfy a conditional expression (1). The expression (1) is 2.4<¾f2a/f2¾<10.0. COPYRIGHT: (C)2010,JPO&INPIT |
