| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens of which the entire lens system is miniaturized without damaging optical performance and has a variable power ratio of about 4 to 6 in a rear focus system. SOLUTION: The zoom lens is provided with first to fifth lens groups GR1 to GR5 having, positive, negative, positive, positive, and negative refracting powers respectively in order from the object side and has an iris IR arranged in the third lens group GR3 and is so configured that the second lens group GR2 is moved from the object side toward an image surface IMG and the fourth lens group GR4 is moved to compensate movement of the image surface resulting from zooming when zooming from a wide-angle end to a telephoto end is performed. The first lens group GR1 is provided with one front-side lens having a negative refracting power, an optical member bending an optical path, and a rear-side lens group having a positive refracting power, in order from the object side and the zoom lens satisfies ¾β2t¾<0.95 whereinβ2t is the imaging magnification of the second lens group at a subject distance of infinity. COPYRIGHT: (C)2005,JPO&NCIPI
|
