Individual adjustment of pit and land transition locations in an optical disc mastering process

An optimization circuit which generates an optimized modulation signal for writing data to an optical disc, the data comprising a first set of data expressed as a series of data symbols each having a leading edge, a trailing edge and a length corresponding to one of a set of associated nominal symbol lengths, the optimization circuit comprising:

• a first leading edge delay table which provides first leading edge delay values each indicative of an associated leading edge delay for at least selected leading edges of the data symbols;
• a second leading edge delay table which provides second leading edge delay values which correspond to and which vary by a selected amount from the first leading edge delay values;
• a first trailing edge delay table which provides first trailing edge delay values each indicative of an associated trailing edge delay for at least selected trailing edges of the data symbols;
• a second trailing edge delay table which provides second trailing edge delay values which correspond to and which vary by a selected amount from the first leading edge delay values;
• and
• an embedded data encoder circuit which selectively applies the first and second leading edge delay values and the first and second trailing edge delay values to the series of data symbols to selectively embed a second set of data onto the first set of data to generate the optimized modulation signal, the second set of data having a separate informational content apart from the informational content of the first set of data so that the informational content of the first set of data is stored in relation to lengths of pits and lands on the optical disc and the informational content of the second set of data is stored in relation to variations of the lengths of the pits and lands, wherein the second set of data provides hidden codes associated with the optical disc which are substantially undetectable to a human upon visual inspection of the optical disc.

A system for writing data to an optical disc, comprising:

• a signal processing circuit which generates an initial modulation signal by modulating a set of data to form a series of data symbols, each data symbol having a leading edge, a trailing edge and a nominal symbol length corresponding to a population of preselected symbol lengths, the signal processing circuit including a first power supply to provide electrical power to remaining portions of the signal processing circuit;
• a master driver circuit operably coupled to the signal processing circuit to receive and reclock the initial modulation signal to provide a reclocked modulation signal, the master driver circuit comprising:
• a latch configured to receive and temporarily store successive portions of the initial modulation signal;
• a master oscillator, coupled to the latch, which generates and supplies a master clock at a selected frequency to reclock the modulation signal at the selected frequency of the master clock;
• and
• an analog power supply which uses a transformer to rectify alternating current (ac) electrical power to provide direct current (dc) electrical power for use by the master oscillator and the latch, the analog power supply electrically and mechanically isolated from the first power supply of the signal processing circuit;
• and
• an optimization circuit, coupled to the master driver circuit, which generates an optimized modulation signal for modulating the writing of the data to the optical disc by selectively adjusting at least selected leading and trailing edges of the series of data symbols to improve optical disc readback characteristics.