Patent ID: 7529168

Claim:
A recording/reproduction method, comprising the steps of: generating a binary signal by converting a reproduction signal to a binary form; generating a synchronization signal using the binary signal, the synchronization signal being in synchronization with a clock signal; measuring a time interval between the binary signal and the synchronization signal and measuring an edge shift amount between the time interval and a clock time interval specified by the clock signal; and changing a parameter of a recording pulse based on the edge shift amount, wherein the reproduction signal is a signal obtained by reproducing an arbitrary random signal sequence, as a function of the edge shift amount, wherein the step of measuring the edge shift amount comprises measuring a leading edge time interval between a mark leading edge of the binary signal and a mark trailing edge of the synchronization signal, measuring a leading edge shift amount between the leading edge time interval and the clock time interval, measuring a trailing edge time interval between a mark trailing edge of the binary signal and a mark leading edge of the synchronization signal, and measuring a trailing edge shift amount between the trailing edge time interval and the clock time interval, and wherein the measuring step comprises measuring a jitter value; the recording pulse contains a first pulse, a multipulse, and a cooling pulse; and the step of changing the parameter of the recording pulse comprises changing a movement amount of the first pulse based on the leading edge shift amount, changing a movement amount of the cooling pulse based on the trailing edge shift amount, and changing a movement amount of the multipulse based on the jitter value.