Patent ID: 6987345
Filing Date: 2006-01-17
Classification: H02N,H02P

Abstract:
1. A vibration type actuator drive controller for controlling a drive speed of a vibration type actuator adapted to excite a vibration member by applying an A.C. signal to an electromechanical energy transducer to obtain a drive force, comprising: an encoder which outputs a pulse signal having a period adapted to change in correspondence to the drive speed of the vibration type actuator; a counter which carries out up-count from a first value to a second value larger than the first value at predetermined time intervals while the vibration type actuator is accelerated; clock output unit which outputs a clock signal having a frequency corresponding to a count value of the counter; measurement unit which measures the period of the pulse signal outputted from the encoder by counting clock pulses of the clock signal outputted from the clock output unit; and control unit which controls the drive speed of the vibration type actuator such that the period of the pulse signal measured by the measurement unit becomes a predetermined target value.