Information recording apparatus and method, information reproducing apparatus and method, and computer program

An information recording method comprising:

• a first judging process of judging whether or not an absolute value of a tracking error signal is greater than or equal to a predetermined first threshold value;
• a detecting process of detecting, as a detection angle, a rotation angle of an information recording medium when it is judged that the absolute value of the tracking error signal is greater than or equal to the first threshold value;
• a second judging process of judging whether or not the judgment that the absolute value of the tracking error signal is greater than or equal to the first threshold value is performed at the same detection angle;
• a holding process of holding tracking servo near the detection angle if it is judged by said second judging process that the judgment that the absolute value of the tracking error signal is greater than or equal to the first threshold value is performed, at the same detection angle;
• and
• a stopping process of stopping the hold of the tracking servo if it is judged by said second judging process that the judgment that the absolute value of the tracking error signal is not greater than nor equal to the first threshold value is performed, at the same detection angle,
• each of the judgment by said first judging process, the detection by said detecting process, and the judgment by said second judging process being performed in parallel with information recording onto the information recording medium.

An information reproducing apparatus comprising:

• a first judging device for judging whether or not an absolute value of a tracking error signal is greater than or equal to a predetermined first threshold value;
• a detecting device for detecting, as a detection angle, a rotation angle of an information recording medium when it is judged that the absolute value of the tracking error signal is greater than or equal to the first threshold value;
• a second judging device for judging whether or not the judgment that the absolute value of the tracking error signal is greater than or equal to the first threshold value is performed at the same detection angle;
• a holding device for holding tracking servo near the detection angle if it is judged by said second judging device that the judgment that the absolute value of the tracking error signal is greater than or equal to the first threshold value is performed, at the same detection angle;
• and
• a stopping device for stopping the hold of the tracking servo if it is judged by said second judging device that the judgment that the absolute value of the tracking error signal is not greater than nor equal to the first threshold value is performed, at the same detection angle,
• each of the judgment by said first judging device, the detection by said detecting device, and the judgment by said second judging device being performed in parallel with information reproduction onto the information recording medium.

An information reproducing method comprising:

• a first judging process of judging whether or not an absolute value of a tracking error signal is greater than or equal to a predetermined first threshold value;
• a detecting process of detecting, as a detection angle, a rotation angle of an information recording medium when it is judged that the absolute value of the tracking error signal is greater than or equal to the first threshold value;
• a second judging process of judging whether or not the judgment that the absolute value of the tracking error signal is greater than or equal to the first threshold value is performed at the same detection angle;
• a holding process of holding tracking servo near the detection angle if it is judged by said second judging process that the judgment that the absolute value of the tracking error signal is greater than or equal to the first threshold value is performed, at the same detection angle;
• and
• a stopping process of stopping the hold of the tracking servo if it is judged by said second judging process that the judgment that the absolute value of the tracking error signal is not greater than nor equal to the first threshold value is performed, at the same detection angle,
• each of the judgment by said first judging process, the detection by said detecting process, and the judgment by said second judging process being performed in parallel with information reproduction onto the information recording medium.