Vibration actuator with two vibration modes

A vibration actuator, comprising:

• a vibration element, which simultaneously generates a radial symmetric expansion vibration mode, such that said vibration element expands and contracts in a radial direction, and a non-axisymmetric planar vibration mode, such that said vibration element bends to and fro in a non-axisymmetric manner within a same plane as said radial symmetric expansion vibration is generated, to thereby drive a relative movement member;
• and
• a support unit including a plurality of structural elements, which supports said vibration element, wherein said plurality of structural elements are arranged in superimposed layers with respect to said vibration element in a direction perpendicular to a vibration plane of said non axially symmetric planar vibration mode,
• wherein front and rear surfaces of an elastic member, of said vibration element, are equally deformed by a pair of electrical energy to mechanical energy conversion elements, of said vibration element.

A vibration actuator, comprising:

• a vibration element formed as a circular plate with a central hole;
• a base member to which said vibration element is fixed;
• and
• a support member to support said vibration element at said central hole to fix said support member to said base member, wherein one side of said support member is fixed to said base member and another side of said support member is fixed to said vibration element, and
• wherein an elastic portion is provided between a portion to which said base member is fixed and a portion to which said vibration element is fixed.

A vibration actuator, comprising:

• a vibration element, which simultaneously generates a radial symmetric expansion vibration mode, such that said vibration element expands and contracts in a radial direction, and a non-axisymmetric planar vibration mode, such that said vibration element bends to and fro in a non-axisymmetric manner within a same plane as said radial symmetric expansion vibration is generated, to thereby drive a relative movement member;
• and
• a base member to which said vibration element is fixed,
• wherein said vibration element includes at least one superimposed layer structure having a pair of electrical energy to mechanical energy conversion elements and an elastic member sandwiched between said pair of electrical energy to mechanical energy conversion elements, with said elastic member including a ring shaped portion, each side of which one of said pair of electrical energy to mechanical energy conversion elements is stuck,
• a cylindrical shaped support portion is formed integrally with said ring shaped portion to fix said vibration element to said base member, and
• said support portion is provided with an elastic portion that suppresses a transmission of vibration generated in said vibration element to said base member.