ZOOM LENS AND IMAGING APPARATUS

摘要

The zoom lens substantially consists of a positive first lens group which is fixed while changing magnification, a negative second lens group which moves while changing magnification, a positive third lens group which moves while changing magnification, and a positive fourth lens group which is fixed while changing magnification in this order from the object side. The image formation magnification rates of the second lens group and the third lens group simultaneously pass a −1× point while changing magnification from the wide angle to the telephoto. The second lens group substantially consists of a negative second-a lens group and a positive second-b lens group which independently move while changing magnification in this order from the object side, and the third lens group substantially consists of a positive third-a lens group and a positive third-b lens group which independently move while changing magnification in this order from the object side.

主权项

1. A zoom lens substantially consisting of:
a first lens group having a positive refractive power, which is fixed while changing magnification; a second lens group having a negative refractive power and a magnification change function, which moves while changing magnification; a third lens group having a positive refractive power, which moves while changing magnification and corrects variations in an imaging plane due to changes in magnification; and a fourth lens group having a positive refractive power and an image formation action, which is fixed while changing magnification and in which a stop is disposed on the most-object side, in this order from the object side; wherein image formation magnification rates of the second lens group and the third lens group simultaneously pass a −1× point when changing magnification from the wide angle end to the telephoto end; the second lens group substantially consists of a second-a lens group having a negative refractive power and a second-b lens group having a positive refractive power in this order from the object side, the second-a lens group and the second-b lens group independently moving while changing magnification from the wide angle end to the telephoto end; and the third lens group substantially consists of a third-a lens group having a positive refractive power and a third-b lens group having a positive refractive power in this order from the object side, the third-a lens group and the third-b lens group independently moving while changing magnification from the wide angle end to the telephoto end.