Patent ID: 8884493
Filing Date: 2014-11-11
Classification: B06B,B08B,G02B,G03B,H01L,H02N

Abstract:
1. A vibration generating device, comprising: a piezoelectric element including a piezoelectric material that contains Pb at 1,000 ppm or lower interposed between electrodes, the piezoelectric material having a resonance frequency that changes to a higher frequency side when an alternating voltage is applied; a vibration member to which the piezoelectric element is connected; a power source for applying the alternating voltage to the piezoelectric element; and a control section for controlling a frequency of the alternating voltage applied by the power source, wherein the vibration generating device generates vibration in the vibration member by applying the alternating voltage to the piezoelectric element from the power source, wherein the control section controls the frequency of the alternating voltage applied to the piezoelectric element so that the frequency of the alternating voltage applied to the piezoelectric element is successively changed from a low frequency side to a high frequency side in a frequency range including a change range of a resonance frequency of the piezoelectric element, and wherein the control section controls the frequency of the alternating voltage applied to the piezoelectric element so that a change rate of the frequency of the alternating voltage is set larger than a change rate of the resonance frequency of the piezoelectric element.