US Patent 7097367 Optical element retracting mechanism for a photographing lens

An optical element retracting mechanism includes a linearly movable ring, a swingable holder positioned inside and supporting the linearly movable ring; a holding device holding the swingable holder, and a retracting device which rotates the swingable holder about a pivot such that the retractable optical element retracts to a position which deviates from the optical axis. The holding device includes an adjusting shaft and includes an eccentric pin, wherein the eccentric pin is engaged with the swingable holder to set a limit for rotational movement of the swingable holder, and a spring which biases the swingable holder to rotate the swingable holder in an advancing direction to engage the swingable holder with the eccentric pin. A position of the retractable optical element is varied in the operational state, in a plane generally orthogonal to the optical axis, by a rotation of the adjusting shaft.