| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens which adopts an inner focus mode, is small-sized and light-weight, has high imaging performance, and allows the reduction in weight, the increase in automatic focusing response speed, and the structure simplification of a focusing mechanism, and to provide a zoom lens which, even in the case of a zoom ratio of 10 or more, does not require the increase in weight and size of a zoom lens optical system and allows a lens barrel to have a rational size. <P>SOLUTION: The zoom lens comprises, in order from the object side, a first lens group G1 having a positive refracting power, a second lens group G2 having a negative refracting power, a third lens group G3 having a positive or negative refracting power, and a fourth lens group G4 having a positive refracting power as a whole. The fourth lens group G4 comprises, in order from the object side, a lens group 4A, a lens group 4B which has a negative refracting power and is moved in a direction approximately vertical to the optical axis during a vibration-proof process, and a follow-up lens group 4C. <P>COPYRIGHT: (C)2012,JPO&INPIT |
