Patent ID: 6157603
Filing Date: 2000-12-05
Classification: G11B,H03L

Abstract:
A disk reproduction apparatus comprising:a photoelectric transducer for optically reading data recorded on a disk and for converting said data into an electric signal;an amplifier for amplifying said electric signal supplied from said photoelectric transducer;a data slice circuit for binarizing said electric signal supplied from said amplifier, to generate a modulated signal;a PLL circuit for generating a first clock signal and a frequency control signal in accordance with a change of a reproduction speed of data, based on said modulated signal supplied from said data slice circuit; anda data processing circuit for demodulating said modulated signal supplied from said data slice circuit, based on said first clock signal supplied from said PLL circuit, to reproduce data, whereinsaid data slice circuit includesa clock signal generator circuit for generating a second clock signal not synchronized with said modulated signal, based on said frequency control signal generated by said PLL circuit,a comparator for comparing said electric signal supplied from said amplifier with a reference voltage, to output one of data items ""0"" and ""1"", in correspondence with said electric signal and said reference voltage,a first divider for dividing said second clock signal, to generate a first integration reference clock signal,a differential data calculator for integrating a differential value between a period of said data item ""0"" and a period of said data item ""1"" supplied from said comparator, based on said first integration reference clock signal, and outputs a differential data, anda digital/analog converter supplied with said differential data outputted from said differential data calculator, for converting said differential data into an analog voltage, and for supplying said analog voltage as said reference voltage to said comparator.