Vibration Actuator and adjustment method therefor

An adjusting method for a vibration actuator in which a drive signal is applied to excite an electromechanical converting element adhered to a surface of an elastic member to generate a longitudinal vibration vibrating in a plane parallel to the other surface of said elastic member contacting a relative moving member maintained in pressure contact with the other surface and a bending vibration vibrating in a direction crossing said contacting surface, thereby generating a relative motion between said elastic member and said relative moving member, and wherein a resonance frequency of said longitudinal vibration generated in said elastic member is higher than a resonance frequency of said bending vibration generated in said elastic member, the adjusting method comprising the step of:

• working said elastic member to adjust the difference in the resonance frequencies of said longitudinal and bending vibrations, so that the resonance frequency of said longitudinal vibration is higher than the resonance frequency of said bending vibration by a predetermined value.

An adjusting method for a vibration actuator in which a drive signal is applied to excite an electromechanical converting element adhered to a surface of an elastic member to generate a longitudinal vibration vibrating in a plane parallel to the other surface of said elastic member contacting a relative moving member maintained in pressure contact with the other surface and a bending vibration vibrating in a direction crossing said contacting surface, thereby generating a relative motion between said elastic member and said relative moving member, and wherein a resonance frequency of said longitudinal vibration generated in said elastic member is higher than a resonance frequency of said bending vibration generated in said elastic member, the adjusting method comprising the step of:

• reducing the length, in the longitudinal direction, of frequency adjusting portions provided on the end faces, in said longitudinal direction, of said elastic member, thereby adjusting the difference in the resonance frequencies of said longitudinal and bending vibrations, so that the resonance frequency of said longitudinal vibration is higher than the resonance frequency of said bending vibration by a predetermined value.

An adjusting method for a vibration actuator in which a drive signal is applied to excite an electromechanical converting element adhered to a surface of an elastic member to generate a longitudinal vibration vibrating in a plane parallel to the other surface of said elastic member contacting a relative moving member and a bending vibration vibrating in a direction crossing said contacting surface, thereby generating a relative motion between said elastic member and said relative moving member, and wherein a resonance frequency of said longitudinal vibration generated in said elastic member is higher than a resonance frequency of said bending vibration generated in said elastic member, the adjusting method comprising the step of:

• providing on the end faces and/or the lateral faces, in the longitudinal direction, of said elastic member, with mass lacking portions for reducing the mass of said elastic member, thereby adjusting the difference in the resonance frequencies of said longitudinal and bending vibrations, so that the resonance frequency of said longitudinal vibration is higher than the resonance frequency of said bending vibration by a predetermined value.