| 摘要 |
PURPOSE:To assure accurate tracking control by feeding minutely the position of a reproduction head with a feed mechanism to compensate the displacement degree of an electric-mechanic transducing part for tracking. CONSTITUTION:When it is decided that the tracking control amount obtained by a bimorph plate 5 consisting of a compensation amount detecting circuit 20, a bimorph driving circuit 21 and the piezoelectric element of an electric-mechanical transducer using an A/D converter 28 exceeds a prescribed level, the output of a level decider 33 is inverted to a high level to open an AND gate 42. Then a program counter 29 is reset by a permission signal C delivered from the gate 42 during a vertical flyback time. The output of the counter 29 is kept at a low level until the counter 29 counts up to the value set by the converter 28, and a switch 32 is closed via an AND gate 30 to drive a head feed motor 9. Meanwhile a switch 24 is changed over by an attenuator 23 which works in response to the signal C, and the plate 5 has no displacement. Then the displacement of the plate 5 is compensated by a minute shift of the head. Thus the accurate tracking is secured. |
