Patent ID: 8649248

Claim:
An optical disk device configured to radiate laser light onto an information recording medium having information tracks, in order to record information thereon and to reproduce, by use of reflected light therefrom, the information recorded on the information recording medium, the optical disk device comprising: a laser light source configured to radiate laser light; a laser driver circuit configured to generate a drive current to drive the laser light source; a waveform equalizer circuit configured to equalize a reproduced signal obtained from the reflected light; a Viterbi decoder circuit configured to conduct Viterbi decoding for a waveform output from the waveform equalizer circuit, in order to output a binary signal; a Viterbi decoding reference value control circuit configured to change a reference value of the Viterbi decoder circuit, based on the waveform output from the waveform equalizer circuit and the binary signal; a Viterbi decoding reference value correction circuit configured to equalize a value of a Viterbi decoding reference value generated using a binary signal pattern configured to be symmetric in a time-axis direction; an equalization error detector circuit configured to detect an amount of an equalization error, based on a difference between the waveform output from the waveform equalizer circuit and the reference value outputted from the Viterbi decoding reference value correction circuit; a recording waveform generator circuit configured to control the laser driver circuit, based on information to be recorded and a recording strategy; and a recording strategy adjuster circuit configured to adjust parameters of the recording strategy, based on the equalization error amount.