| 摘要 |
PROBLEM TO BE SOLVED: To provide a high variable power zoom lens having small collapsible thickness and high performance. SOLUTION: In the zoom lens constituted of four groups, equipped with a 1st lens group G1 having positive refractive power, a 2nd lens group G2 having negative refractive power, a 3rd lens group G3 having positive refractive power and a 4th lens group G4, the 1st lens group G1 to the 4th lens group G4 are moved while changing space between the respective lens groups in order to perform zooming operation from a wide angle end to a telephoto end, and the 2nd lens group G2 is constituted of three lenses. The zoom lens has an aperture diaphragm S arranged nearer to an image side at the wide angle end than at the telephoto end between the 2nd lens group G2 and the 3rd lens group G3, and satisfies following conditional expressions. (1) 7<(β<SB>2T</SB>×β<SB>3T</SB>×β<SB>4W</SB>)/(β<SB>2W</SB>×β<SB>3W</SB>×β<SB>4T</SB>)<15 and (2) 7<(β<SB>2T</SB>×β<SB>3T</SB>)/(β<SB>2W</SB>×β<SB>3W</SB>)<15, provided thatβ<SB>nT</SB>: the magnification of an n-th lens group at the telephoto end, andβ<SB>nW</SB>: the magnification of the n-th lens group at the wide angle end. COPYRIGHT: (C)2006,JPO&NCIPI
|
