| 摘要 |
PROBLEM TO BE SOLVED: To provide a telephoto zoom lens which has variable magnification ratio of about 4, in which the image face curvature generating at variable magnification is fully compensated, F number is comparatively small, the angle of emission of ambient light flux is also small, and which is compact and has superior optical performance. SOLUTION: The telephoto zoom lens comprises 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, having positive refractive power, in this order starting from an object side and the variable magnification ratio is about 4. Upon zooming from a wide-angle end to a telephoto end, the 1st lens group G1, the 3rd lens group G3 and the 4th lens group G4 are moved toward an object side on an optical axis to satisfy certain conditions. COPYRIGHT: (C)2006,JPO&NCIPI
|
