Optical disc and optical disc device

A reproducing method for reproducing an optical disc, containing at least one recording layer, and providing a management area on said at least one recording layer, said management area having recorded information representing if other recording layers with different recording density are present in said optical disc, said reproducing method comprising:

• reading said recorded information on said management area;
• and
• reproducing data recorded on said at least one recording layer,
• wherein said at least one recording layer has the highest recording density in said optical disc,
• wherein said information has a first information section representing presence and absence of a first recording layer conforming to a first optical disc standard and a second information section representing presence and absence of a second recording layer conforming to a second optical disc standard, and represents absence of said other recording layers with different recording density by bit values of 00.

An identifying method for identifying the type of an optical disc, containing at least one recording layer, and providing a management area on said at least one recording layer, said management area having recorded information representing if other recording layers with different recording density are present in said optical disc, said identifying method comprising:

• reading said recorded information on said management area;
• and
• identifying the type of said optical disc based on said recorded information,
• wherein said at least one recording layer has the highest recording density in said optical disc,
• wherein said information has a first information section representing presence and absence of a first recording layer conforming to a first optical disc standard and a second information section representing presence and absence of a second recording layer conforming to a second optical disc standard, and represents absence of said other recording layers with different recording density by bit values of 00.

An optical disc comprising:

• at least one recording layer;
• and
• a management area provided on said at least one recording layer, said management area having recorded information representing if other recording layers with different recording density are present in said optical disc,
• wherein said at least one recording layer has the highest recording density in said optical disc,
• wherein said information has a first information section representing presence and absence of a first recording layer conforming to a first optical disc standard and a second information section representing presence and absence of a second recording layer conforming to a second optical disc standard, and represents absence of said other recording layers with different recording density by bit values of 00.

A recording apparatus for recording data on an optical disc, containing at least one recording layer, and providing a management area on said at least one recording layer, said recording apparatus comprising:

• a laser light source for producing a laser beam;
• a focusing device for focusing said laser beam on said at least one recording layer of said optical disc;
• a photo detector for detecting a return laser beam from said optical disc and generating a data signal responsive thereto,
• wherein said focusing device focuses said laser beam onto said management area to read information stored therein,
• wherein said at least one recording layer has the highest recording density in said optical disc,
• wherein said information has a first information section representing presence and absence of a first recording layer conforming to a first optical disc standard and a second information section representing presence and absence of a second recording layer conforming to a second optical disc standard, and represents absence of said other recording layers with different recording density by bit values of 00.

A playback apparatus for reproducing data recorded on an optical disc, containing at least one recording layer, and providing a management area on said at least one recording layer, said management area having recorded information representing if other recording layers with different recording density are present in said optical disc, said playback apparatus comprising:

• a laser light source for producing a laser beam;
• a focusing device for focusing said laser beam on said at least one recording layer of said optical disc;
• a photo detector for detecting a return laser beam from said optical disc and generating a data signal responsive thereto,
• wherein said focusing device focuses said laser beam onto said management area to read information stored therein,
• wherein said at least one recording layer has the highest recording density in said optical disc,
• wherein said information has a first information section representing presence and absence of a first recording layer conforming to a first optical disc standard and a second information section representing presence and absence of a second recording layer conforming to a second optical disc standard, and represents absence of said other recording layers with different recording density by bit values of 00.

An identifying apparatus for identifying the type of an optical disc, containing at least one recording layer, and providing a management area on said at least one recording layer, said management area having recorded information representing if other recording layers with different recording density are present in said optical disc, said identifying apparatus comprising:

• a laser light source for producing a laser beam;
• a focusing device for focusing said laser beam on said at least one recording layer of said optical disc;
• a photo detector for detecting a return laser beam from said optical disc and generating a data signal responsive thereto,
• wherein said focusing device focuses said laser beam onto said management area to read information stored therein,
• wherein said at least one recording layer has the highest recording density in said optical disc,
• wherein said information has a first information section representing presence and absence of a first recording layer conforming to a first optical disc standard and a second information section representing presence and absence of a second recording layer conforming to a second optical disc standard, and represents absence of said other recording layers with different recording density by bit values of 00.