| 摘要 |
PURPOSE:To measure the turning angle of a rotor, by regarding a progressive wave of the stator outer peripheral face as a kind of protractor and by detecting its surface vibration displacement. CONSTITUTION:A rotor turning-angle measuring apparatus for an ultrasonic wave motor is equipped with a motor by means of a rotor 1, a ring stator 2, a piezoelectric ceramic element 3 and others; a driving signal generator circuit 4 for said element 3, and a driver circuit 5. Further, said apparatus is equipped with reflecting mirrors 8, 10 and a condensing lens 9 so as to detect a surface vibration displacement in optically non-contact manner, and rotates integrally with the rotor 1. Thus, a progressive-wave surface vibration displacement signal 11 detected by an optical minute vibration sensor body 6 is sent to a phase-difference detector circuit 13 via an amplifier circuit 12 so that a phase difference between a reference signal from the driving signal generator circuit 4 and said displacement signal 11 is measured. These measured data are sent to a turning-angle operator 15, where the turning-angle of said rotor 1 is computed finally. |
