Patent ID: 7755251

Claim:
A control apparatus for a vibration wave driven apparatus that applies driving signals to a vibrator including an electro-mechanical energy conversion element to thereby produce an oval motion of a driving section of the vibrator by which a driven body made in contact with the driving section is moved, comprising: an operation amount determining unit adapted to determine an operation amount of the vibrator; a frequency determining unit adapted to determine a frequency of the driving signals based on the operation amount; and an oval ratio determining unit adapted to determine an oval ratio of the oval motion by changing a phase difference between the driving signals based on the operation amount, wherein said frequency determining unit sets the frequency of the driving signals to a frequency upper limit value when the phase difference between the driving signals is changed by said oval ratio determining unit, and sets the frequency of driving signals to a frequency lower than the frequency upper limit value when the phase difference between the driving signals is not changed by said oval ratio determining unit.