Patent ID: 6980385

Claim:
An information regenerating apparatus comprising: a recording medium recording information; a read out circuit which generates a regenerated signal corresponding to recorded information from the recording medium; a conversion circuit which carries out sampling of the regenerated signal on the basis of a supplied clock signal to convert the regenerated signal to gain information; a regenerating circuit which carries out a signal detection on the basis of the gain information to output digital data corresponding to the information; a phase error detecting circuit which carries out a phase error signal calculated by using a delay circuit carrying out a delayed sampling from the conversion circuit; a detection circuit carrying out a detected data from the conversion circuit having same detection capability of the regenerating circuit; a phase calculate circuit calculating the phase error signal based on outputs of the delay circuit and the detection circuit; and an oscillation circuit which adjusts the clock signal on the basis of the phase error signal obtained by the phase error detecting circuit; wherein the detection circuit in the phase error detecting circuit comprises: a delay circuit for carrying out gain information from an output of the conversion circuit; and a Fixed Delay Tree Search (FDTS) circuit for outputting to the detection circuit using at least one piece of an output of the delay circuit on the basis of FDTS algorithm, which detects maximum likelihood detected data within a finite period by using the output of the delay circuit.