FILM WINDING AND REWINDING MECHANISM OF CAMERA

摘要

PURPOSE:To decrease power consumption by forming respective vibrators out of a ring-shaped piezoelectric element and divided electrodes in a circumferential direction fixed on the surface of the piezoelectric element, and making the diameter of the second vibrator larger than that of the first vibrator. CONSTITUTION:The second vibrator 4 consists of a ring-shaped piezoelectric element and divided electrodes in a circumferential direction fixed on its surface in the same way as the first vibrator 8, and its diameter is set a little larger than that of the vibrator 8. In film and winding and rewinding, positive or negative voltage is applied to a facing one of the divided electrodes in a circumferential direction in one of the vibrators 4, 8. The applying direction of the voltage is moved in a circumferential direction in order to shift the expanding direction of the vibrator along the circumferential direction and turn a fork guide 2 or a spool 7 coming into one-point contact with the vibrators 4, 8. Since the diameter of the vibrator 4 is made larger than that of the vibrator 8, larger rewinding torque than the holding power of the spool can be attained, providing rewinding only by applying voltage to the vibrator 4.