| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a novel imaging lens system having good performance and compactness. <P>SOLUTION: In an imaging lens, in order from the object side to the image side, a first group having positive refractive power, a diaphragm, and a second group having positive refractive power are disposed, and focusing is performed by displacing the first group and the second group by different extending amounts. The first group is composed of four or less lenses including two or more negative lenses and one positive lens, and two lenses closest to the object side are both negative lenses and the negative lens closest to the object side is a negative meniscus lens with a convex surface facing the object side. The second group is composed of five lenses including at least a set of a cemented lens of a positive lens and a negative lens. When an air gap between the two negative lenses located closest to the object side in the first group is d11-2, and an air gap between the negative lens located second closest to the object side in the first group and a lens adjacent to the image side of this negative lens is d12-3, a condition(1) of 0.0<d12-3/d11-2<0.4 is satisfied. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
