| 摘要 |
PURPOSE:To detect a read signal without error by detecting the deficient or surplus compensating state of a correction circuit and changing a voltage for compensation applied to the correction circuit so as to bring the correction circuit into the optimum compensation state. CONSTITUTION:If the quantity of compensation of the correction circuit 4 is excessive, an output signal D of the correction circuit 4 as shown in waveform S, in which a spurious pseudo peak is emphasized in a data pattern period of a signal A at a value of '000'. The peak position of the signal D corresponding to '0' in succession to '1' of the signal A is shifted in a direction causing a time lead, the leading position of a signal G corresponding to said peak position is led and shifted in the arrow. In this case, converse to the quantity of deficient compensation of the correction circuit 4, a multivibrator 18 outputs a signal P, a multivibrator 19 outputs a signal '0' with respect to a time width tw3 where a switch SW2 is closed, a time width tw1 where a switch SW2 is closed is decreased, a capacitor C is charged, a terminal voltage DELTAV rises and the correction circuit 4 is controlled in a direction to reduce the quantity of compensation.
|
