Abstract: A piezoelectric ultrasonic motor includes: a drive piezoelectric material wherein a plurality of piezoelectric elements, which are polarized by opposite polarities along a circumferential direction around a rotation shaft, are alternately arranged, and a vibration-control piezoelectric material wherein a plurality of piezoelectric elements, which are arranged along a circumferential direction around the rotation shaft and polarized by opposite polarities, are arranged to correspond to the plurality of piezoelectric elements of the drive piezoelectric material, wherein AC power and another AC power having a phase difference with respect to the AC power are respectively applied to the piezoelectric material and the vibration-control piezoelectric material, in a vibration damping area of the drive piezoelectric material.

Abstract: An optical device includes a lens assembly that performs a forward/backward movement in an optical axis direction. The optical device also includes at least one first driving device that generates a first driving force that causes the lens assembly to perform the forward/backward movement in the optical axis direction. The optical device further includes at least one second driving device that generates a second driving force in a direction that is opposite to the moving direction of the lens assembly. The second driving force may be formed to be equal to or smaller than the first driving force so that the reciprocating amplitude of the lens assembly may be reduced when the lens assembly reciprocates before and after the focusing position. The optical device as described above may be variously implemented according to embodiments.

Abstract: A piezoelectric ultrasonic motor includes: a drive piezoelectric material wherein a plurality of piezoelectric elements, which are polarized by opposite polarities along a circumferential direction around a rotation shaft, are alternately arranged, and a vibration-control piezoelectric material wherein a plurality of piezoelectric elements, which are arranged along a circumferential direction around the rotation shaft and polarized by opposite polarities, are arranged to correspond to the plurality of piezoelectric elements of the drive piezoelectric material, wherein AC power and another AC power having a phase difference with respect to the AC power are respectively applied to the piezoelectric material and the vibration-control piezoelectric material, in a vibration damping area of the drive piezoelectric material.

Abstract: An optical device includes a lens assembly that performs a forward/backward movement in an optical axis direction. The optical device also includes at least one first driving device that generates a first driving force that causes the lens assembly to perform the forward/backward movement in the optical axis direction. The optical device further includes at least one second driving device that generates a second driving force in a direction that is opposite to the moving direction of the lens assembly. The second driving force may be formed to be equal to or smaller than the first driving force so that the reciprocating amplitude of the lens assembly may be reduced when the lens assembly reciprocates before and after the focusing position. The optical device as described above may be variously implemented according to embodiments.