PURPOSE: To miniaturize the device and reduce the cost by driving a projecting part without using a motor by using a piezoelectric element as a driving means, and thinning the thickness of the device main body.
CONSTITUTION: When a plug is inserted into a plug socket, an AC voltage is applied to a first and a second piezoelectric elements 33, 34 from a first and a second electrodes 31, 32 of a vibrator 30. A first and a second piezoelectric elements 33, 34 generate vibration corresponding to a frequency of this voltage. In this case, since the directions of currents flowing to a first and a second piezoelectric elements 33, 34 are opposite each other, a voltages applied to a first and a second piezoelectric elements 33, 34 have phases different from each other by 180°C, respectively, expansion and contraction of a first and a second piezoelectric elements 33, 34 become opposite each other. As a result, the vibrator 30 vibrates in the thickness direction. Following this vibration, a projecting part 20 also vibrates, and the sole of a foot of a user is massaged. Since the projecting part 20 is vibrated by using the piezoelectric element as a driving means, thickness of the device main body is thin.
KAI MASASHI
INADA MASAMI
