| 摘要 |
PROBLEM TO BE SOLVED: To obtain the variable power optical system with a vibrationproof function which obtain a still image by optically correcting the defocusing of a photographed image when the variable power optical system vibrates. SOLUTION: The variable power optical system has four lens groups, i.e., a 1st group L1 with positive refracting power which is fixed at the time of power variation and focusing, a 2nd group L2 which has a power varying function and negative refracting power, a 3rd group L3 with positive refracting power, and a 4th group L4 which has both a correcting function for correcting an image plane varying owing to power variation and a function for focusing and positive refracting power in order from the object side, and the 3rd group L3 has two lens groups with positive refracting power and also has one lens group FL fixed and the other lens group SL moved at right angles to the optical axis to correct the defocusing of a photographed image when the variable power optical system vibrates. |
