A drive unit being characterized in that a movable object can be prevented
from being tilted when the movable object is stopped using a restricting
member. The drive unit comprises a piezoelectric element; a rod provided
at an end of the piezoelectric element; a movable object, which is
frictionally engaged with the rod and the movable range of which is
restricted using the restricting members; and drive pulse generating
means for applying drive signals to the piezoelectric element, wherein
the drive pulse generating means apply a first wave drive signal for
vibrating the rod so that the movable object moves toward the restricting
member when the movable object is moved to a position where the movable
object is close to the restricting member, and temporarily apply a second
wave drive signal for vibrating the rod so that the movable object is
moved in a direction of movement away from the restricting member after
the movable object is made contact with the restricting member, and then
stop the application of the drive signal.