| 摘要 |
PURPOSE:To stably control to drive a vibration wave motor by driving it by second driving mode means only when the phase output of a vibration detecting converter is stable, and driving it by first driving mode means when it is unstable. CONSTITUTION:A driving circuit for a vibration wave motor 6 is composed of a controller 7 having a microcomputer for controlling to drive a whole circuit, S-phase.A-phase comparators 8a, 8b, a shift register 8c, edge trigger type phase comparators 8d, 8m, lag-lead filters 8f, 8n, positive/reverse conversion switch 8h, n-the frequency divider 8q, a counter 8r, etc. The switch 8h is operated by the instruction of the controller 7, a signal from the register 8c is selected, and the rotating direction of the motor is altered by changing its phase relationship. The converter 8t is so controlled by the controller 7 that, when the detection signal becomes unstable, it is driven by first driving mode means of an open loop, while when it becomes stable, it is driven by second driving mode means of a closed loop. |
