Patent ID: 7952815

Claim:
A lens barrel comprising: an imaging optical system which includes a front optical element and a rear optical element which are relatively movable in an optical axis direction; a spring installed between said front optical element and said rear optical element so as to increase a distance therebetween; a reference barrel which includes a forward-facing limit surface and a rearward-facing limit surface which face forward and rearward in said optical axis direction, respectively; a first position control mechanism which includes a first rotational member and a first limit member, said first position control mechanism varying a position of said front optical element in said optical axis direction relative to said reference barrel in accordance with a rotation of said first rotational member; and a second position control mechanism which includes a second rotational member and a second limit member, said second position control mechanism varying a position of said rear optical element in said optical axis direction relative to said reference barrel in accordance with a rotation of said second rotational member; wherein said first limit member is brought into contact with said rearward-facing limit surface by a forward biasing force of said spring to determine a position of said first position control mechanism while said second limit member is brought into contact with said forward-facing limit surface by a rearward biasing force of said spring to determine a position of said second position control mechanism.