| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens and so on that are able to simplify the configuration of a lens. <P>SOLUTION: The zoom lens includes, in order from the object side, a positive first lens group G1, a negative second lens group G2, a positive third lens group G3, and a negative fourth lens group G4. When zooming from a wide-angle end to a telephoto end, the space between the first lens group and the second lens group widens, the space between the second lens groups and the third lens group narrows, and the space between the third lens group and the fourth lens group changes, and all the lens groups from the first lens group to the fourth lens group move along an optical axis. Additionally, the zoom lens has a brightness diaphragm moved integrally with the third lens group when zooming takes place. The fourth lens group is composed of a single negative lens, and the first lens group is composed of a single positive lens. The bending factor of the positive lens satisfies the following condition: -1.5<(RL<SB POS="POST">11F</SB>+RL<SB POS="POST">11R</SB>)/(RL<SB POS="POST">11F</SB>-RL<SB POS="POST">11R</SB>)<0. <P>COPYRIGHT: (C)2012,JPO&INPIT |
