| 主权项 |
1. A control apparatus for a vibration-type actuator, wherein
the vibration-type actuator includes a plurality vibrators each having a contact portion contacting an object to be driven, such that, responsive to a common alternating current signal to the plurality vibrators, the plurality vibrators move, through the contact portions, the object relative to the vibrators, to generate an elliptical motion of the object, wherein the control apparatus comprises a frequency determining unit for setting a frequency of the alternating current signal, and the frequency determining unit sets the frequency of the alternating current signal for changing an ellipticity of the elliptical motion, within an overlapping frequency range in which frequency ranges of ellipticity changing each set for each of the plurality of vibrators are overlapped, and the frequency ranges of changing the ellipticity are set for the vibrators as a frequency ranges between an upper limit and a lower limit, such that the lower limit is a maximum resonant frequency in all case of changing the ellipticity, and the upper limit is larger than the lower limit and is a maximum frequency for the relative movement of the driving member. |
