Zoom lens and image capturing apparatus

Abstract

There is provided a zoom lens including first and second lens groups independently movable in an optical axis direction in an optical system. Before and after switching between two modes different in minimum focusing distance, a lens group to rule focusing changes between the first and second lens groups or a relative position between the first and second lens groups changes.

What is claimed is: 
     
         1 . A zoom lens comprising:
 first and second lens groups independently movable in an optical axis direction in an optical system,   wherein, before and after switching between two modes different in minimum focusing distance, a lens group to rule focusing changes between the first and second lens groups or a relative position between the first and second lens groups changes.   
     
     
         2 . The zoom lens according to  claim 1 ,
 wherein, in a mode shorter in minimum focusing distance of the two modes, a focusing distance range is changed to a short distance side by shifting any one of the first and second lens groups per zoom position by a certain amount.   
     
     
         3 . The zoom lens according to  claim 1 ,
 wherein at least one of the first and second lens groups independently moves in zooming.   
     
     
         4 . The zoom lens according to  claim 1 ,
 wherein both of the first and second lens groups move in focusing, with movement amounts of the first and second lens groups associated with each other.   
     
     
         5 . The zoom lens according to  claim 1 ,
 wherein the first and second lens groups are arranged alongside on a closest side to an image in the optical system.   
     
     
         6 . The zoom lens according to  claim 1 ,
 wherein each of the first and second lens groups includes one lens.   
     
     
         7 . The zoom lens according to  claim 1 ,
 wherein at least one of the first and second lens groups includes one plastic lens.   
     
     
         8 . A zoom lens comprising: in order from an object side,
 a first zoom lens group having positive refractive power;   a second zoom lens group having negative refractive power;   a third zoom lens group having positive refractive power; and   a fourth zoom lens group having positive refractive power,   wherein a negative lens disposed on a closest side to an image in the third lens group and a positive lens included in the fourth zoom lens group are independently movable in an optical axis, and   wherein, before and after switching between two modes different in minimum focusing distance, a lens to rule focusing changes between the negative lens and the positive lens or a relative position between the negative lens and the positive lens changes.   
     
     
         9 . A zoom lens comprising: in order from an object side,
 a first zoom lens group having positive refractive power;   a second zoom lens group having negative refractive power;   a third zoom lens group having positive refractive power;   a fourth zoom lens group having negative refractive power; and   a fifth zoom lens group having positive refractive power,   wherein a negative lens included in the fourth zoom lens group and a positive lens included in the fifth zoom lens group are independently movable in an optical axis direction, and   wherein, before and after switching between two modes different in minimum focusing distance, a lens to rule focusing changes between the negative lens and the positive lens or a relative position between the negative lens and the positive lens changes.   
     
     
         10 . An image capturing apparatus comprising:
 a zoom lens including first and second lens groups independently movable in an optical axis direction in an optical system; and   an image sensor converting an optical image formed by the zoom lens into an electric signal,   wherein, before and after switching between two modes different in minimum focusing distance, a lens group to rule focusing changes between the first and second lens groups or a relative position between the first and second lens groups changes.   
     
     
         11 . The image capturing apparatus according to  claim 10 , further comprising:
 a selection part configured to select one of the two modes.