A lens driving apparatus includes a lens holder and a driver for providing
linear motion to the lens holder along an optical axis of the lens. The
driver includes an electromagnetic mechanism, provided at the outer
circumference of the lens holder in an enclosing manner, for generating a
torque around the optical axis; and a switching mechanism for switching
the generated torque to a linear driving force along the optical axis so
as to linearly move the lens holders. The driver surrounds the lens
holder along the outer circumference to allow a smaller sized lens
driving apparatus than that where the lens holder is at a side of the
lens driving apparatus. In addition, the switching mechanism prevents the
lens holder from moving in the optical axial direction, when power is
turned off or even when an external force is applied to the lens holder.