A first drive shaft is disposed with a first piezoelectric element at one end and a second piezoelectric element at the other end. A second drive shaft is disposed with the second piezoelectric element at one end and a third piezoelectric element at the other end. First and second lens holding frames are frictionally engaged with the first and second drive shafts respectively in a slidable manner. The first, second and third piezoelectric elements are expanded and contracted according to a drive signal and move the first and second lens holding frames in an axial direction respectively. When the moving velocity of the first and second lens holding frames are reduced, the phase difference between the drive signals, which are output to the respective piezoelectric elements, is adjusted so that the moving velocity becomes higher.