Control method for marking label side of optical disc
View Patent ↗An inner ring signal and an outer ring signal according to specific patterns formed on the label side of the optical disc are generated. Timing starts when the outer ring signal reveals the end of a positioning pattern and stops to obtain a timing value when the inner ring signal reveals the start of a square wave defining a specified spoke. A starting spoke is defined according to the inner ring signal and the specified spoke. A deviation bit value is calculated according to the timing value and a bit number of a data to be marked on a certain track of the optical disc. The data is rotated according to the deviation bit value, and then marked on the certain track, starting with the starting spoke.
1. A control method for marking a label side of an optical disc, comprising steps of:
generating an inner ring signal and an outer ring signal according to specific patterns formed on the label side of the optical disc, wherein the specific patterns include a positioning pattern in an outer ring and a plurality of spokes in an inner ring;
starting timing when the outer ring signal reveals the end of the positioning pattern;
stopping timing and obtaining a timing value when the inner ring signal reveals the start of a square wave defining a specified spoke;
defining a starting spoke according to the inner ring signal and the specified spoke;
calculating a deviation bit value according to the timing value and a bit number of a data to be marked on a certain track of the optical disc; and
rotating the data according to the deviation bit value, and marking the rotated data on the certain track, starting with the starting spoke.
2. The method according to claim 1 wherein the square wave defining the specified spoke is the first square wave detected after the timing starts, and the specified spoke is Spoke No. 395 .
3. The method according to claim 1 wherein the outer ring signal and inner ring signal are generated by an optical head and a spoke detector of an optical disc recording apparatus, respectively.
4. The method according to claim 1 wherein the specific patterns include a media ID, a saw tooth and an index mark including the positioning pattern.
5. The method according to claim 1 wherein the starting spoke is defined by counting a certain number of square waves following the square wave defining the specified spoke.
6. The method according to claim 1 wherein the calculation of the deviation bit value includes steps of:
calculating a time period per cycle of rotation of the optical disc;
calculating a ratio of the timing value to the time period per cycle of rotation of the optical disc; and
multiplying the bit number of the data to be marked on the certain track by the ratio.
7. The method according to claim 6 wherein the time period per cycle of rotation of the optical disc is equal to the overall time of the occurrence of 400 square waves of the inner ring signal.
8. The method according to claim 6 wherein the data is leftward rotated by the deviation bit value.