Patent ID: 6853499
Filing Date: 2005-02-08
Classification: G02B

Abstract:
1. A lens barrel comprising: a plurality of lens groups; a cam cylinder comprising a cam configured to move a portion of said plurality of lens groups toward positions corresponding to a predetermined photographing state and a predetermined collapsed state along an optical axis; a cam follower configured to move said portion of the plurality of lens groups by engaging with said cam and rotating relatively to said cam cylinder along said cam; and an elastomer for biasing said cam follower along said optical axis to slide the cam follower on said cam, a biased force of said elastomer varying in response to a moved position of said cam follower; wherein a developed shape of said cam has different angles to a plane depending on a position in a collapsible region in which said cam follower is moved from a photographing state to a collapsed state, the developed share of the cam is configured to suppress an increase in a rotational torque during movement of the cam follower between the photographing and collapsed states, and the portion of the plurality of lens groups comprises a lens group configured to be biased by the elastomer in a direction opposite to a collapsing direction.