Abstract: An optical apparatus includes a first lens for zooming, a second lens which is arranged in rear of the first lens on an optical axis to correct a shift of a focal plane caused by a motion of the first lens, a vibration wave motor arranged to serve as a drive source for the second lens, and a decision circuit which decides a driving direction and a driving speed of the vibration wave motor by using at least information on the positions of the first and second lenses.

Abstract: A lens 2 is mechanically connected to an image processor 3 having a different mount from that of the lens 2 via a converting adapter 1. A computer 4 is electrically connected to the converting adapter 1 and the lens 2 via electrical terminals 6 and 7. A command transmitted from the computer 4 is converted by an internal converter 8 of the converting adapter 1. The computer 4 controls an internal actuator 2c of the lens 2 by transmitting a command through communication.

Abstract: A vibration type motor device in which a travelling wave is formed by applying a cyclic signal to a piezoelectric member so as to vibrate a vibration member, thereby driving a moving member. When a cyclic signal actually applied to the piezoelectric member has a frequency near the resonance frequency, it is determined whether the moving member can be properly driven.

Abstract: A vibration wave motor for driving a movable member by a travelling vibration wave generated by applying a periodic signal to an electro-mechanical energy transducer element such as an electrostrictive device or piezoelectric device is disclosed. A drive status of the vibration wave motor is detected, a phase difference between the detected signal and the periodic signal applied to the transducer element is detected, a frequency of the periodic signal is selected such that the phase difference is equal to a predetermined constant and the vibration wave motor is driven in a resonance state.

Abstract: A vibration wave motor generates a travelling vibration wave by applying periodic voltages of different phases to electro-mechanical energy transducers located at two different positions on a stator, and drives a movable member by the vibration wave. In order to adjust the speed of the vibration wave motor, the phase difference between the periodic voltages applied to the transducer is adjusted or the application of the periodic voltage to one or both of the transducers is selectively blocked.

Abstract: In a vibration wave motor, one of periodic signals of different phases to be applied to first and second electro-mechanical energy conversion elements is generated without frequency-dividing an output of an oscillator and a phase-shifted signal with respect to the output of the oscillator is generated by a phase locked loop and applied to the other conversion element.

Abstract: This specification discloses a vibration wave motor in which frequency signals of different phases are applied to electro-mechanical energy converting elements such as electrostrictive elements disposed at different positions to thereby form a travelling vibration wave in a member in which the converting elements are disposed and a moving member is driven by the vibration wave and particularly in which the phase difference between the frequency signals applied to the energy converting elements is held at a particular value.