VIBRATION ACTUATOR SUITABLE FOR USE IN MAGNETIC FIELD ENVIRONMENT AND MEDICAL SYSTEM

摘要

A vibration actuator suitable for use in a magnetic field environment. Vibration is excited in a vibration element in pressure contact with a driven element, for causing relative movement of the driven element and the vibration element. The vibration element includes an elastic body of which a main ingredient is electrically insulating, dielectric, or semi-conductive, and an electromechanical energy conversion element. A first electrode having an open loop structure is provided on a surface of a piezoelectric body of the electromechanical energy conversion element via which surface the piezoelectric body is joined to the elastic body. Second electrodes are provided on the piezoelectric body in a manner opposed to the first electrode via the piezoelectric body. A conduction path electrically connects the first electrode and at least one of the second electrodes. A gap is formed between each adjacent ones of the second electrodes.

主权项

1. A vibration actuator in which a vibration element and a driven element are brought into pressure contact with each other, and vibration is excited in the vibration element to thereby move the driven element and the vibration element relative to each other,
the vibration element comprising: an elastic body of which a main ingredient comprises a material which is electrically insulating, dielectric, or semi-conductive; and an electromechanical energy conversion element that is joined to said elastic body, said electromechanical energy conversion element comprising: a piezoelectric body; a first electrode that is provided on a surface of said piezoelectric body, via which surface said piezoelectric body is joined to said elastic body, said first electrode having an open loop structure; at least two second electrodes that are provided in a manner opposed to said first electrode via said piezoelectric body; and a conduction path that electrically connects said first electrode and at least one second electrode of said at least two second electrodes, wherein a gap is formed between said at least two second electrodes.