| 摘要 |
PURPOSE:To reduce the fall of level of difference wave form by providing means for detecting the position of read out truck and securing output in a demodulator circuit of differential mode, and making the signal delaying time variable in accordance with the position of a truck. CONSTITUTION:Servo head 6 is interlocked with a head 1 and arranged such that delay quantity of differential circuit 4' is varried by a truck counter 7 which read out servo information. When the value indicated by a truck counter represents an inner truck, a switching control circuit 23 selects output L1 which has a large delay quantity and when the value of the truck counter 7 represents an out truck 1, the circuit 23 selects output Ln which has a small delay quantity to reduce the fall of differential wave form. Thus, the possibility of detecting 0 as 1 is reduced and the device is useful for overcoming the difficulty in the conventional apparatus. |
