US Patent 7808729 Driving device

A driving device includes a piezoelectric element that expands and contracts by the application of voltage, a driving shaft fixed to one end of the piezoelectric element in a direction of the optical axis, a lens holder fixed to the other end of the piezoelectric element in the direction of the optical axis, a friction portion frictionally engaged with the driving shaft, and a base that supports the driving shaft such that the driving shaft is capable of moving along the optical axis. The friction portion includes a receiving portion and a leaf spring that are arranged in a manner such that the driving shaft extending along the optical axis is clamped therebetween in the radial direction.