Lens barrel and imaging device

Abstract

A lens barrel having an image forming optical system including a first optical system and a second optical system which is moveable independently from the first optical system, a first driving portion which drives the first optical system during a magnification changing operation of the image forming optical system, and a second driving portion which drives the second optical system during the magnification changing operation, along with driving the second optical system during a focus adjustment of the image forming system.

1 . A lens barrel comprising an image forming optical system including a first optical system and a second optical system which is moveable independently from the first optical system,
 a first driving portion which drives the first optical system during a magnification changing operation of the image forming optical system, and   a second driving portion which drives the second optical system during the magnification changing operation, along with driving the second optical system during a focus adjustment of the image forming system.   
     
     
         2 . The lens barrel according to  claim 1 , wherein a driving amount of the second optical system by the second driving portion during the focus adjustment is determined according to a focal length of the image forming optical system. 
     
     
         3 . The lens barrel according to  claim 1 , wherein the first driving portion is a cam ring having a cam which engages with a holding member which holds the first optical system. 
     
     
         4 . A lens barrel according to  claim 1 , comprising a guide shaft which guides movement of the second optical system, provided at a holding member which holds the second optical system, and
 a support member which supports the guide shaft.   
     
     
         5 . The lens barrel according to  claim 4 , wherein the second driving portion comprises a linear actuator which drives the guide shaft with respect to the support member. 
     
     
         6 . The lens barrel according to  claim 5 , wherein the linear actuator is arranged at the second optical system side of the support member. 
     
     
         7 . The lens barrel according to  claim 4 , comprising
 a second guide shaft, which guides the movement of the second optical system, provided at the holding member which holds the second optical system,   a second linear actuator which drives the second guide shaft, and   a control portion which selectively controls the driving of the second actuator.   
     
     
         8 . An imaging device provided with the lens barrel of  claim 1 .