Nikon Corporation

Tunemi Gonda

Tsuyoshi Matsumoto

Tadao Takagi

Michihiro Tobe

Isao Sugaya

Mitsuhiro Okazaki

Mina Kobayashi

Nobuyoshi Nasu

Tomoaki Suzuki

Mine Shibata

A vibration actuator includes a vibration element, which simultaneously generates a radial symmetric expansion vibration mode in which it expands and contracts in the radial direction and a non-axisymmetric planar vibration mode in which it bends to and fro in a non-axisymmetric manner within a single plane, and thereby drives a relative movement member, and a base member to which the vibration element is fixed. The vibration element includes at least one superimposed layer structure comprising a pair of electrical energy to mechanical energy conversion elements and an elastic member sandwiched between the pair of electrical energy to mechanical energy conversion elements. The elastic member includes a ring shaped portion to both the sides of which the pair of electrical energy to mechanical energy conversion elements are stuck, and a cylindrical shaped support portion, formed integrally with the ring shaped portion, which fixes the vibration element to the base member. The support portion includes an elastic portion which suppresses the transmission of vibration generated by the vibration element to the base member.

Vibration actuator with two vibration modes

A vibration actuator drive device using a linear type of ultrasonic actuator to drive a rotary member with high accuracy and good efficiency. The vibration actuator drive device includes an ultrasonic actuator which, by applying drive signals, produces longitudinal vibration and bending vibration to generate a drive force, and a rotary member in contact with the ultrasonic actuator. The combination of longitudinal vibration and bending vibration in the ultrasonic actuator generates relative motion in the rotary member having a circular locus of predetermined width. A compression mechanism causes compressive contact of the ultrasonic actuator with the rotary member. The longitudinal vibration vibrates in a direction about parallel to the direction of the drive force, and the bending vibration vibrates in a direction intersecting the longitudinal vibration. A drive force is transmitted to the rotary member at the inner circumferential side of the circular locus, and greatly differs from the drive force which is transmitted to the rotary member at the outer circumferential side. A lens barrel including a vibration actuator drive device drives a focus adjustment lens group in the optical axis direction by the conversion of the rotary motion of the rotary member to linear motion.

Vibration actuator and lens barrel

A vibration actuator harmoniously generates both longitudinal and bending vibrations to thereby induce motion in a relative moving member. The vibration actuator improves drive efficiency and reduces soldering defects by providing an improved mounting between an electrical energy delivery member and electrodes. The elastic member is connected to an electro-mechanical converting element to convert electrical energy into mechanical displacement. The electrodes are disposed on the electro-mechanical converting element in a location approximately at a node of vibration on the elastic member. A plurality of electrically conductive sections are disposed between the plurality of thermal energy non-conducting sections and about the electrodes. The thermal energy non-conducting sections reduce damage to the electro-mechanical converting elements during the soldering process while the electrically conductive sections electrically connect each electrode to a respective electro-mechanical converting element.

Vibration actuator

A vibration actuator produces a driving force by generating elliptic motion in the surface of an elastic member through electromechanical converting elements. The vibration actuator then generates relative motion between the elastic member and a relative moving member which is in compressive contact with the elastic member The electro-mechanical converting elements, in the form of piezoelectric elements, generate longitudinal vibrations and bending vibrations in the elastic member. The elastic member has a rectangular plate shape and includes a plurality of driving force output units which contact the relative moving member. Plural sliding members are respectively mounted on portions of the plurality of driving force output units such that the sliding members do not fully extend across the driving force output units in a short side direction.

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Yamato, Japan

Tunemi Gonda