Method and apparatus for demodulating WAP of optical disc

A method for demodulating an address from a wobble signal recorded on a disc, wherein the disc records a SYNC field and an address field that are configured by a plurality of wobble data units including a first wobble data unit of the SYNC field and a second wobble data unit of the address field, the first wobble data unit including a synchronization signal, and the second wobble data unit including a head invert phase wobble, having a plurality of bits, and an address, the method comprising:

• generating a plurality of wobble data units using wobble signal recorded on the disc;
• detecting the synchronization signal from the first wobble data unit of the SYNC field;
• counting the plurality of wobble data units based on the detection of the synchronization signal;
• continuously generating a plurality of demodulation signals for setting a timing at which the address in the second wobble data unit of the address field is demodulated based on a count value of the plurality of wobble data units;
• detecting the head invert phase wobble from the second wobble data unit of the address field and checking whether the plurality of wobble data units are properly readable;
• demodulating a plurality of addresses in the second wobble data unit of the address field in response to each of the plurality of demodulation signals, wherein detection accuracy of the synchronization signal and the head invert phase wobble is set relatively low to improve read rate of the plurality of addresses;
• detecting whether the plurality of addresses that are demodulated in response to the demodulation signals are proper;
• and
• correcting, when detecting that the plurality of addresses are proper, generation timing of one of the plurality of demodulation signals so as to be synchronized with generation timings of the demodulation signal that demodulates the proper plurality of addresses.

An apparatus for demodulating an address from a wobble signal recorded on a disc, wherein the disc records a SYNC field and an address field that are configured by a plurality of wobble data units including a first wobble data unit of the SYNC field and a second wobble data unit of the address field, the first wobble data unit including a synchronization signal, and the second wobble data unit including a head invert phase wobble, having a plurality of bits, and an address, the apparatus comprising:

• a SYNC detector for detecting the synchronization signal from the first wobble data unit of the SYNC field and generating a first detection signal;
• a counter for counting the plurality of wobble data units in response to the first detection signal from the SYNC detector and generating a demodulation signal for setting a timing at which the address in the second wobble data unit of the address field is demodulated based on a count value of the plurality of wobble data units;
• an address demodulator for detecting the head invert phase wobble in the second wobble data unit of the address field in response to the demodulation signal and demodulating the address in the second wobble data unit of the address field;
• and
• an IPW monitor for detecting in full bit the head invert phase wobble of the second wobble data unit of the address field in parallel with the detection of the head invert phase wobble and for generating a second detection signal when properly detecting the head invert phase wobble;
• wherein the counter corrects the count value in response to the second detection signal so that the demodulation signal is generated at a timing in which the head invert phase wobble is properly detectable in full bits.

An apparatus for demodulating an address from a wobble signal recorded on a disc, wherein the disc records a SYNC field and an address field that are configured by a plurality of wobble data units including a first wobble data unit of the SYNC field and a second wobble data unit of the address field, the first wobble data unit including a synchronization signal, and the second wobble data unit including a head invert phase wobble, having a plurality of bits, and an address, the apparatus comprising:

• a SYNC detector for detecting the synchronization signal from the first wobble data unit of the SYNC field and generating a first detection signal;
• a counter for counting the plurality of wobble data units in response to the detection signal from the SYNC detector and continuously generating a plurality of demodulation signals for setting a timing at which the address in the second wobble data unit of the address field is demodulated based on a count value of the plurality of wobble data units;
• an address demodulator for detecting the head invert phase wobble from the second wobble data unit of the address field in response to each of the plurality of demodulation signals and demodulating a plurality of addresses in the second wobble data unit of in the address field;
• and
• an address comparator for detecting whether the plurality of addresses are proper, and when detecting that the plurality of addresses are proper, providing the counter with a correction signal for correcting generation timing of one of the plurality of demodulation signals so as to be synchronized with generation timings of the demodulation signal that demodulates the proper plurality of normal addresses.