Patent ID: 9240746
Filing Date: 2016-01-19
CPC Classification: H02P

Claim Text:
1. A driving apparatus for a vibration-type actuator comprising an electro-mechanical energy conversion element and a vibration member wherein a relative position of a contact portion of the vibration member and a contact portion of a movable member is changed by application of an AC voltage to the electro-mechanical energy conversion element, the driving apparatus comprising: a voltage amplitude command unit configured to output an amplitude command signal to indicate a target value of an amplitude of the AC voltage applied to the vibration-type actuator; a pulse width command unit configured to monotonically increase a pulse width command signal and a change rate of the pulse width command signal according to an increase in the amplitude command signal, and configured to output a pulse width command signal; and a pulse signal generation unit configured to generate a pulse signal having a pulse width corresponding to the pulse width command based on the pulse width command output from the pulse width command unit and having the same frequency as the AC voltage, wherein the pulse width command unit is configured to monotonically increase the pulse width command signal and the change rate of the pulse width command signal by using at least one of a function of an amplitude in an amplitude command signal and a table for converting an amplitude command signal to a pulse width command signal, wherein the function of the amplitude in the amplitude command signal is a function independent of time, and wherein the table converts the amplitude command signal to a pulse width command signal independently of time.