Optical disk unit

A method for adjusting a rotating speed of an optical disk mounted in an optical disk unit, the optical disk including a plurality of concentric tracks, each of the plurality of tracks including sub-code Q information including an address, a track number, and a time code, the method comprising the steps of:

• moving an optical head to a first track of the optical disk corresponding to a program start position;
• moving said optical head from the first track to a second track, the second track being spaced from said first track by a predetermined number of said plurality of tracks;
• reading the time code of said second track;
• making only two comparisons between the read time code from the second track, a first preset value and a second preset value, the first preset value being lower than the second preset value;
• and
• controlling said optical disk unit to operate at a first rotating speed if the read time code is greater than the first preset value, at a second rotating speed if the read time code is less than the first preset value and greater than the second preset value, and at a third rotating speed if said read time code is less than said second preset value;
• wherein the first rotating speed corresponds to a linear speed of the optical disk which is 1.2 m/s relative to the optical head, the second rotating speed corresponds to 1.3 m/s, and the third rotating speed corresponds to 1.4 m/s.

A method for adjusting a rotating speed of an optical disk mounted in an optical disk unit, the optical disk including a plurality of concentric tracks, each of the plurality of tracks including subcode Q information including an address, a track number, and a time code, the method comprising the steps of:

• moving an optical head to a first track of the optical disk corresponding to a program start position;
• moving said optical head from the first track to a second track, the second track being spaced from said first track by a predetermined radial distance along said optical disk;
• reading the time code of said second track;
• making only two comparisons between the read time code from the second track a first preset value and a second preset value, the first preset value being lower than the second preset value;
• and
• controlling said optical disk unit to operate at a first rotating speed if the read time code is greater than the first preset value, at a second rotating speed if the read time code is less than the first preset value and greater than the second preset value, and at a third rotating speed if said read time code is less than said second preset value;
• wherein the first rotating speed corresponds to a linear speed of the optical disk which is 1.2 m/s relative to the optical head, the second rotating speed corresponds to 1.3 m/s, and the third rotating speed corresponds to 1.4 m/s.