| 摘要 |
PURPOSE:To give shift control to a head, by detecting a large extent of the step shift in case the head has a big shift out of the tracking position and then detecting the position of the head with sufficiently high resolution when the shift of the head is minute, respectively. CONSTITUTION:The voltage signal supplied from a head 11 is applied to a comparator 23 from a wave detecting circuit 22. A control circuit 26 starts the counting of a counter 25 simultaneously with an integral network 24 by a control command given for the initial measurement. The counter 25 continues the counting until the reference voltage signal reaches a state corresponding to a level of reproduction, and the count value is stored in the circuit 26. The circuit 26 gives a driving command to a motor driving circuit 27 after reading the count information, and step shift is given to the head 11 by means of a pulse motor 20. The range of the count number is discriminated by the tracking state to set an extent of the step shift for the head 11. |
