| 摘要 |
A zoom lens having three lens groups I, II, and III, in order from the object side, of positive, positive and negative refractive power, respectively, is made to have a simple drive mechanism which shifts the first lens group and the third lens group as one unit when power is varied. A diaphragm 2 is arranged nearest the image-side surface of the first lens group. When shifting from the wide-angle end to the telephoto end, each lens group is shifted so as to increase the spacing between the first lens group and the second lens group and to decrease the spacing between the second lens group and the third lens group. By making one or more surfaces in the second lens group and the third lens group aspheric, the three-group zoom lens can be made compact and various aberrations can be favorably corrected.
|
