PHASE-MODULATED DECODE CLOCK GENERATING CIRCUIT, PHASE INVERSION DETECTING CIRCUIT, PHASE INVERSION PATTERN DETECTING CIRCUIT, DECODE CIRCUIT, AND PHASE-MODULATED SIGNAL REPRODUCING DEVICE FOR RECORDING MEDIUM HAVING PHASE-MODULATED SIGNAL

摘要

PROBLEM TO BE SOLVED: To provide a phase-modulated decode clock generating circuit which can be easily integrated in a simple configuration of a digital circuit.;SOLUTION: As shown in Figure 2, a signal waveform (g) which dulles the waveform of a phase inversion part is binarized as a 'zero level' threshold, and a phase-modulated decode clock is generated on the basis of the binarized signal (h). A phase inversion signal decode clock (k) obtained as a logical add of a pulse string corresponding to the rising and falling of the binarized signal (i) and a phase inversion detected pulse (j) which is a pulse generator operating only when the binarized signal is in a H level (E in Figure 2) and which is generated when its length is between the one period length (A in Figure 2) and the half period length of a wobble signal in which the H level length of the binarized signal is not phase-inversed, is generated. Accordingly, a PLL circuit required conventionally is unnecessary, and a simple phase-modulated decode clock generating circuit can be easily integrated in a small size.;COPYRIGHT: (C)2002,JPO