Patent ID: 7450833
Filing Date: 2008-11-11
Classification: G02B,G03B

Abstract:
1. A lens barrel comprising: a radially-retractable optical element constituting a part of a photographing optical system, said radially-retractable optical element being movable between a photographing position located on an optical axis of said photographing optical system, and a radially-retracted position located on an off-optical-axis position; a biasing device for biasing said radially-retractable optical element toward said photographing position; a swing member which is provided independent from said radially-retractable optical element and is rotatable about a rotation axis extending parallel to said optical axis, said swing member pushing said radially-retractable optical element against a biasing force of said biasing device to move said radially-retractable optical element to said radially-retracted position; a rotational ring drivable to rotate about a rotational axis parallel to said optical axis so as to cause at least one optical element, which is different from said radially-retractable optical element, to move along said optical axis; and a rotation transmitting device configured to transmit a rotational driving force of said rotational ring to said swing member when said photographing optical system changes from a photographic state to a non-photographing state, said rotation transmitting device comprising: wherein: said swing member completes said movement of said radially-retractable optical element to said radially-retracted position before said photographing optical system reaches said non-photographing state during a retracting operation from said photographic state of said photographing optical system, said rotation transmitting device does not transfer said rotational driving force of said rotational ring to said swing member upon completion of said movement of said radially-retractable optical element to said radially-retracted position, said rotation transmitting gear engages with said circumferential gear of said rotational ring in said photographic state, and said rotation transmitting gear disengages from said circumferential gear by said rotational ring moving relative to said rotation transmitting gear in a direction of said rotational axis at a predetermined angular position of said rotational ring before said photographing optical system reaches said non-photographing state during a retracting operation from said photographic state of said photographing optical system.