US Patent 7626775 Lens drive apparatus

A lens drive apparatus includes a lens holder holding a lens, a gear rotated by rotational force of a driving source, and a cam gear meshed with the gear. The lens holder is moved in an optical path direction by the cam gear. The lens holder has an engagement portion engaged with a cam portion of the cam gear and is arranged to move in response to a change in the cam portion in conjunction with the rotation of the cam gear. The cam gear has a teeth portion composed of plural teeth arranged in a circular shape. The teeth portion has an non-meshed portion not meshed with the gear and thicker than other teeth. The number of the pluses or the number of the rotation of the driving source is preset, whereby a position of the lens holder is recognized.