Patent ID: 9568706
Date: 2017-02-14
CPC Classifications: G02B,G03B

Claim:
1. A lens barrel holding a photographing optical system which is a zoom lens constituted by five groups of a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, a fourth lens group with negative refractive power and a fifth lens group with positive refractive power, the lens barrel being capable of shortening a total length thereof when not taking photographs, comprising: a cylindrical cam barrel arranged to be rotatable around an optical axis; a first lens driving section driving the cam barrel around the optical axis at a time of a magnification changing operation of the photographing optical system; a plurality of first cam grooves carved on an outer circumferential surface of the cam barrel; a plurality of second cam grooves carved on an inner circumferential surface of the cam barrel; a third lens group holding barrel formed in a cylindrical shape, the third lens group holding barrel including, in the cylindrical shape, a moveable barrel holding the third lens group movable in a direction orthogonal to the optical lens; and a lens shifting mechanism section driving the movable barrel holding the third lens in the direction orthogonal to the optical axis in the third lens group holding barrel, the lens shifting mechanism section including a biasing spring biasing the movable barrel to the third lens group holding barrel in the optical axis direction, and a ball sandwiched between the third lens group holding barrel and the movable barrel by a biasing force of the biasing spring in the optical axis direction, wherein a first lens group holding barrel holding the first lens group has a plurality of cam followers that are recessed in the first cam grooves; and each of a second lens group holding barrel holding the second lens group and the third lens group holding barrel holding the third lens group has a plurality of cam followers that are recessed in the second cam grooves.