| 摘要 |
PURPOSE:To execute the position compensation of a movable member and the position control of a recording medium by a simple structure by controlling the movable member in accordance with a signal obtained by a detecting means for detecting a state of the movable member to which a head is attached, and obtaining a signal for showing a rotating state of a rotating member. CONSTITUTION:A rotating member 2 is fixed to a shaft 1, and plural heads 6 are attached to a rotating upper drum 3 through a bimorph plate 5. Control voltage of the bimorph plate 5 is applied through a slip ring 13 and a cable 14. Detecting magnets 15, 15' are attached onto the bimorph plates 5, 5', and a detecting coil 16 is attached onto a fixed lower drum 4 so as to be opposed. A detecting output of the coil 16 is supplied to a driving circuit, and a position shift of the head due to a time aging, etc. is compensated. Also, an output of the coil 16 detects rotational phase of the drum 3, and a head switching circuit and a drum controlling circuit are controlled through a phase detecting pulse generating circuit. In this way, it is suppressed that the structure of the rotating member becomes complicated, and recording and reproducing can be executed exactly. |
