Abstract: A circuit for calibration of the NLTS correction value provided for the NLTS correction circuit to realize its high precision of the amount of the NLTS correction. The circuit for calibrating the NLTS correction value of the present invention comprises a duty cycle-voltage converter (D/V converter) for receiving the output signals of the NLTS correction circuit and converting the duty cycle of the signals to voltage values, an A/D converter for converting the analog output from the D/V converter to digital values, and an delay line control device for controlling the amount of delay of each delay line in accordance with the output of the A/D converter. To providing the circuit for calibrating the NLTS correction value of the present invention for the NLTS correction circuit, the amount of delay of the delay lines is required to be controllable with the delay line control device.

Abstract: In a data reproducing apparatus compatibility among plural recording media can be improved. In the data reproducing apparatus, the latest tap coefficient is stored as a tap coefficient in a transversal filter during the normal reproducing operation. This latest tap coefficient is used as an initial value during next reproducing operation. Accordingly, a capture operation for the reproducing operation can be quickly executed. Thus, even when a plurality of recording media are replaced and reproduced in this data reproducing apparatus, a difference between the characteristics of the recording media can be absorbed.