Information storage medium, and data recording, reproducing, detecting and/or evaluating apparatus and method using the same

An information storage medium comprising:

• a first area which stores data modulated by a first modulation method;
• and
• a second area which stores data modulated by a second modulation method,
• wherein the data modulated by the second modulation method are stored by using only parts of pits or spaces formed on the storage medium by the first modulation method.

A data recording apparatus which records information data on an information storage medium, comprising:

• a modulation unit which modulates input information data by a predetermined modulation method according to a first clock signal having a basic clock period for recording or reproducing data to form a modulated bitstream;
• and
• a bit expander which expands bits of the modulated bitstream according to a second clock signal which is a predetermined multiple of the first clock signal so as to form an adjusted modulated bitstream to be recorded as pits with an nT length,
• wherein T is the basic clock period and n is an integer.

A data recording apparatus which records information data on an information storage medium having at least a first area and a second area other than the first area, the apparatus comprising:

• a first modulation unit which modulates input information data according to a first modulation method to produce first modulated data;
• a second modulation unit which modulates the input information data according to a second modulation method to produce second modulated data;
• and
• a recording unit which records the first modulated data as pits or spaces in the first area and records the second modulated data as pits or spaces in the second area,
• wherein the second modulated data uses only parts of pits or spaces formed on the information storage medium by the first modulation method.

A data reproduction apparatus which reproduces data stored on an information storage medium having at least a first area including first modulated data modulated by a first modulation method and a second area other than the first area and which includes second modulated data modulated by a second modulation method, the apparatus comprising:

• a binarizing unit which binarizes a reproduction signal read from the information storage medium and provides a binarized reproduction signal;
• a clock generation unit which generates a reproduction clock signal from the binarized reproduction signal and generates a reduced clock signal obtained by reducing the reproduction clock signal by a predetermined number;
• a first restoration unit which restores the binarized reproduction signal by a first demodulation method corresponding to the first modulation method according to the reproduction clock signal so as to reproduce the first modulated data;
• and
• a second restoration unit which restores the binarized reproduction signal by a second demodulation method corresponding to the second modulation method according to the reduced clock signal so as to reproduce the second modulated data.

A data detection apparatus which detects data on an information storage medium including information data with an nT length, the apparatus comprising:

• a converting unit which converts an optical signal read from the information storage medium into a reproduction signal;
• a binarizing unit which binarizes the reproduction signal and provides a binarized signal;
• and
• a correction unit which corrects a run length of the binarized signal,
• wherein T denotes a cycle of a basic clock signal for recording or reproducing data and n is an integer.

A data evaluating apparatus which detects and evaluates data on an information storage medium which includes information data with an nT length, the apparatus comprising:

• a converting unit which converts an optical signal read from the information storage medium into a reproduction signal;
• a binarizing unit which binarizes the reproduction signal and provides a binarized signal;
• a correction unit which corrects a run length of the binarized signal;
• and
• an error rate detection unit which counts an error rate for the output of the correction unit and evaluates the performance of data detection,
• wherein T denotes a cycle of a basic clock signal for recording or reproducing data and n is an integer.

A data recording method by which information data are recorded on an information storage medium, the method comprising:

• modulating input information data by a predetermined modulation method according to a first clock signal having a basic clock period for recording or reproducing data and providing a modulated bitstream;
• and
• providing an expanded bitstream by bit expanding the modulated bitstream according to a second clock signal which is a predetermined multiple of the first clock signal in order to form the modulated bitstream to be recorded on the information storage medium as pits with an nT length,
• wherein T is the basic clock period and n is an integer.

A data recording method for recording information data on an information storage medium having at least a first area and a second area other than the first area, the method comprising:

• modulating input information data according to a first modulation method to produce first modulated data;
• modulating the input information data according to a second modulation method to produce second modulated data;
• and
• recording the first modulated data as pits or spaces in the first area and recording the second modulated data as pits or spaces in the second area,
• wherein the second modulated data uses only parts of the pits or spaces formed on the information storage medium by the first modulation method.

A data reproduction method of reproducing information data stored on an information storage medium having at least a first area storing first modulated data modulated by a first modulation method and a second area other than the first area and having second modulated data modulated by a second modulation method, the method comprising:

• binarizing a reproduction signal read from the information storage medium and providing a binarized reproduction signal;
• restoring the binarized reproduction signal according to a reproduction clock signal by a first demodulation method corresponding to the first modulation method;
• and
• restoring the binarized reproduction signal according to a clock signal obtained by reducing the reproduction clock signal to 1/N by a second demodulation method corresponding to the second modulation method,
• wherein N is a predetermined number.

A data detection method of detecting information data on an information storage medium, the information data having an nT length, the method comprising:

• binarizing a reproduction signal reproduced from the information storage medium and providing a binarized signal;
• and
• correcting a run length of the binarized signal,
• wherein T denotes a cycle of a basic clock signal for recording or reproducing data and n is an integer.

A data evaluating method of detecting and evaluating information data on an information storage medium which includes the information data with an nT length, the method comprising:

• binarizing a reproduction signal reproduced from the information storage medium and providing a binarized signal;
• correcting a run length of the binarized signal and providing a corrected signal;
• and
• counting an error rate of the corrected signal and evaluating the performance of data detection,
• wherein T denotes a cycle of a basic clock signal for recording or reproducing data and n is an integer.

An information storage medium comprising pits having run lengths to record information data, wherein:

• the information data are recorded by:
• determining run lengths for the pits to be formed to have an nT run length but not to have an (n±1)T run length, and
• recording the information data as the pits using the determined nT run length so as to not form pits having the run length of (n±1)T,
• T is a cycle of a basic clock signal for recording or reproducing data, and
• n is an integer.