Detection of data in burst cutting area of optical disk

An optical disc comprising data in a burst cutting area, the burst cutting area comprising markings causing a marking frequency spectrum when reading out the burst cutting area, wherein the data in the burst cutting area is divided into frames selected to have a standard frame structure being also used for user data outside the burst cutting area.

A method of creating outgoing data to be provided on an optical disk in a burst cutting area, the burst cutting area further comprising markings causing a marking frequency spectrum when reading out the burst cutting area, the method comprises:

• channel coding for receiving processed data to supply the outgoing data having an outgoing data frequency spectrum with suppressed DC-content, and
• data processing for generating the processed data to obtain an outgoing frequency spectrum wherein a low frequency component of the outgoing frequency spectrum causing interference with a frequency component of the marking frequency spectrum is suppressed or not present.

An apparatus for generating outgoing data to be provided on an optical disk in a burst cutting area, the burst cutting area further comprising markings causing a marking frequency spectrum when reading out the burst cutting area, the apparatus comprises:

• a channel encoder for receiving processed data to supply the outgoing data having an outgoing data frequency spectrum with suppressed DC-content, and
• a data processing device for generating the processed data to obtain the outgoing frequency spectrum wherein a low frequency component of the outgoing frequency spectrum causing interference with a frequency component of the marking frequency spectrum is suppressed or not present.

An optical disk comprising data in a burst cutting area, the burst cutting area further comprising markings causing a marking frequency spectrum when reading out the burst cutting area, the data comprising frames comprising a layer indication and a random data sequence, the frames having a data frequency spectrum wherein a frequency component interfering with a low frequent component of the markings is suppressed by pre-coding wherein the data has been obtained by replacing data sequences of an incoming data which is pre-coded by data sequences of pre-coded data, the data comprising data sequences having a smaller low frequent content than the corresponding data sequences of the incoming data, a number of bits of the data sequence of the pre-coded data being larger than a number of bits of a corresponding one of the data sequence of the incoming data,

• wherein the pre-coding was performed by coding the data sequences 00, 01, 10, 11 of the incoming data into the respective corresponding processed data sequences 1010, 0001, 0111, 0101 of the pre-coded data.

An apparatus for reading an optical disk having a burst cutting area comprising markings and data,

• an optical pickup unit for scanning the burst cutting area to obtain a read signal being dependent on both the markings and the data, a frequency spectrum of the read signal comprising a marking frequency spectrum and a data frequency spectrum, and
• a processor for processing the read signal to retrieve both the data and the markings by using filters corresponding to the data frequency spectrum and the marking frequency spectrum, respectively, where the data was obtained by pre-encoding incoming data by replacing data sequences of the incoming data by data sequences of pre-coded data, the outgoing data comprising data sequences having a smaller low frequent content than the corresponding data sequences of the incoming data, a number of bits of the data sequence of the pre-coded data being larger than a number of bits of a corresponding one of the data sequence of the incoming data,
• wherein the pre-coding comprised the step of coding the data sequences 00, 01, 10, 11 of the incoming data into the respective corresponding processed data sequences 1010, 0001, 0111, 0101 of the pre-coded data.

A method of reading an optical disk having a burst cutting area comprising markings and data, the method comprising

• scanning the burst cutting area to obtain a read signal being dependent on both the markings and the data, a frequency spectrum of the read signal comprising a marking frequency spectrum and a data frequency spectrum, and
• processing the read signal to retrieve both the data and the markings by filtering the data frequency spectrum and the marking frequency spectrum, respectively, where the data was obtained by pre-encoding incoming data by replacing data sequences of the incoming data by data sequences of pre-coded data, the outgoing data comprising data sequences having a smaller low frequent content than the corresponding data sequences of the incoming data, a number of bits of the data sequence of the pre-coded data being larger than a number of bits of a corresponding one of the data sequence of the incoming data,
• wherein the pre-coding comprised the step of coding the data sequences 00, 01, 10, 11 of the incoming data into the respective corresponding processed data sequences 1010, 0001, 0111, 0101 of the pre-coded data.