Patent ID: 8817163

Claim:
A foreign substance removal apparatus comprising: an optical member; a first piezoelectric element attached to the optical member and including a first drive electrode and a first detection electrode formed thereon; a second piezoelectric element attached to the optical member and including a second drive electrode and a second detection electrode formed thereon; a drive unit configured to apply power to the first drive electrode to drive the first piezoelectric element, and apply power to the second drive electrode to drive the second piezoelectric element; a vibration detection unit configured to detect a vibration of the optical member based on outputs from the first detection electrode and the second detection electrode; a setting unit configured to set an amount of a driving phase difference between power application to the first drive electrode and power application to the second drive electrode; and a measuring unit configured to measure an amount of a detected phase difference between detection of the vibration of the optical member by the vibration detection unit based on the output from the first detection electrode, and detection of the vibration of the optical member by the vibration detection unit based on the output from the second detection electrode, wherein the setting unit sets a first driving phase difference amount to be set in advance, wherein the setting unit sets a second driving phase difference amount based on the detected phase difference amount measured by the measuring unit when the setting unit sets the first driving phase difference amount, wherein the drive unit applies a first voltage to the first drive electrode and the second drive electrode when the setting unit sets the first driving phase difference amount, wherein the drive unit applies a second voltage to the first drive electrode and the second drive electrode when the setting unit sets the second driving phase difference amount, and wherein the first voltage is lower than the second voltage.