Optical recording method, optical recording apparatus, apparatus for manufacturing a master through exposure process, optical information recording medium and reproduction method

An optical recording apparatus for recording information by irradiating an optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information,

• the optical disc medium having stored thereon a recording compensation value representing change amount of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train,
• the apparatus comprising:
• an encoding section configured to encode record data to generate encoded data which is a combination of marks and spaces;
• a classification section configured to classify the encoded data according to a combination of a mark length of a mark, a space length of a first space that immediately precedes the mark, and a space length of a second space that immediately succeeds the mark;
• reading section configured to read the recording compensation value from the optical disc medium;
• a recording waveform generating section configured to generate the write pulse train for forming the mark in which at least one of the leading end edge position, the trailing end edge position, and the pulse width of the write pulse train is changed by the change amount as represented by the recording compensation value, according to the result of the classification;
• and
• a laser driving section configured to irradiate the optical disc medium with the generated write pulse train to form the plurality of marks on the optical disc medium,
• wherein the space length of the first space is classified in M space length classes (M is an integer equal to or greater than 1) and the space length of the second space is classified in N space length classes (N is an integer equal to or greater than 1),
• wherein the recording compensation value includes:
• a reference value representing at least one of change amounts of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train for a first class that is at least one of:
• a class among the M space length classes;
• and
• a class among the N space length classes, and
• difference information for the reference value, representing at least one of change amounts of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train for at least one class that is different from the first class, and
• wherein:
• in the case of one of the leading end edge position and the pulse width is changed, the recording waveform generating section changes one of the leading end edge position and the pulse width by the change amount as represented by the recording compensation value according to the result of the classification so that M is greater than N;
• and
• in the case of the trailing end edge position is changed, the recording waveform generating section changes the trailing end edge position by the change amount as represented by the recording compensation value according to the result of the classification so that N is greater than M.

An optical disc medium in which information is to be recorded based on an optical recording method for recording information by irradiating the optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information,

• wherein the optical recording method includes the steps of:
• encoding record data to generate encoded data which is a combination of marks and spaces;
• classifying the encoded data according to a combination of a mark length of a mark, a space length of a first space that immediately precedes the mark, and a space length of a second space that immediately succeeds the mark;
• reading a recording compensation value from the optical disc medium, the recording compensation value representing change amount of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train;
• generating a write pulse train for forming the mark, in which at least one of the leading end edge position, the trailing end edge position, and the pulse width of the write pulse train is changed by the change amount as represented by the recording compensation value, according to a result of the classification;
• and
• irradiating the optical disc medium with the generated write pulse train to form the plurality of marks on the optical disc medium,
• wherein the space length of the first space is classified in M space length classes (M is an integer equal to or greater than 1) and the space length of the second space is classified in N space length classes (N is an integer equal to or greater than 1),
• and
• wherein:
• in the case of one of the leading end edge position and the pulse width is changed, the step of generating the write pulse train changes one of the leading end edge position and the pulse width by the change amount as represented by the recording compensation value according to the result of the classification so that M is greater than N;
• and
• in the case of the trailing end edge position is changed, the step of generating the write pulse train changes the trailing end edge position by the change amount as represented by the recording compensation value according to the result of the classification so that N is greater than M,
• the optical disc medium comprising a predetermined area, wherein, in the predetermined area, information about the classification to be used for the classification in the step of classifying, and the recording compensation value are contained,
• wherein the recording compensation value includes:
• a reference value representing at least one of change amounts of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train for a first class that is at least one of:
• a class among the M space length classes;
• and
• a class among the N space length classes, and
• difference information for the reference value, representing at least one of change amounts of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train for at least one class that is different from the first class.

A method for reproducing information from an optical disc medium in which the marks are to be recorded based on an optical recording method for recording information by irradiating the optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information,

• wherein the optical recording method includes the steps of:
• encoding record data to generate encoded data which is a combination of marks and spaces;
• classifying the encoded data according to a combination of a mark length of a mark, a space length of a first space that immediately precedes the mark, and a space length of a second space that immediately succeeds the mark;
• generating a write pulse train for forming the mark, in which at least one of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train is changed by the change amount as represented by a recording compensation value, according to a result of the classification, the recording compensation value representing change amount of the leading end edge position, the trailing end edge position, and the pulse width of the write pulse train;
• and
• irradiating the optical disc medium with the generated write pulse train to form the plurality of marks on the optical disc medium,
• wherein the space length of the first space is classified in M space length classes (M is an integer equal to or greater than 1) and the space length of the second space is classified in N space length classes (N is an integer equal to or greater than 1), and
• wherein:
• in the case of one of the leading end edge position and the pulse width is changed, the step of generating the write pulse train changes one of the leading end edge position and the pulse width by the change amount as represented by the recording compensation value according to the result of the classification so that M is greater than N;
• and
• in the case of the trailing end edge position is changed, the step of generating the write pulse train changes the trailing end edge position by the change amount as represented by the recording compensation value according to the result of the classification so that N is greater than M,
• wherein the optical disc medium including a predetermined area, in which information about the classification to be used for the classification in the step of classifying, and the recording compensation value are contained, and
• wherein the recording compensation value includes:
• a reference value representing at least one of change amounts of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train for a first class that is at least one of:
• a class among the M space length classes;
• and
• a class among the N space length classes, and
• difference information for the reference value, representing at least one of change amounts of a leading end edge position, a trailing end edge position, and a pulse width of the write pulse train for at least one class that is different from the first class,
• the method for reproducing information comprising the step of:
• reproducing the information contained in the optical disc medium by irradiating the optical disc medium with laser light;
• reading the information about the classification to be used for the classification;
• and
• reading the reference value or the difference information from the recording compensation value.