Vibration driving device for a strong magnetic-field environment

A vibration driving device comprising:

• a vibration actuator including a vibrating body and a contact body, the vibrating body including an elastic body and an electromechanical energy conversion element, the contact body being in contact with the vibrating body and movable relatively to the vibrating body;
• and
• a control device including a signal generating circuit and a boosting circuit, the boosting circuit including an air-core transformer electrically connected to the signal generating circuit, wherein
• the vibration actuator is configured to receive a signal output by the control device,
• wherein the air-core transformer has a coupling coefficient k that satisfies an expression:
• 0.6<k<0.9, and
• wherein the air-core transformer has a turns ratio N that satisfies an expression:
• N
• =
• V
• 0
• (
• 4
• /
• π
• )
• ·
• Vi
• ·
• k
• ,
• where Vo represents a peak-to-peak amplitude of an alternating-current voltage signal, Vi represents a peak-to-peak amplitude of a pulse signal, and k represents the coupling coefficient of the air-core transformer.