US Patent 7852722 Optical disk apparatus and playback signal processing method

Provided is an optical disk apparatus which has high read retry ability and high compatibility by performing a proper verify for other apparatuses. The optical disk apparatus includes a playback system capable of arbitrarily changing playback performance, and means which detects and determines a factor causing a read error. Moreover, a read retry is performed by use of playback parameters corresponding to the factor causing the read error. Furthermore, a verify is performed with the playback performance of the playback system lowered.