Optical disc, playback apparatus for optical disc, and apparatus and method for manufacturing optical disc

An optical disc recorded with main information that is to be decrypted using predetermined information by arranging concave or convex recording marks on a spiral track and having a reflective film formed on the concave or convex recording marks,

• wherein
• the main information is recorded in predetermined units each including at least address information and being arranged continuous to one another in a direction of the spiral track;
• the predetermined information is recorded based on first sub information and second sub information;
• the first sub information is provided for each of the predetermined units;
• the first sub information is recorded as being superimposed on the main information by shifting the concave or convex recording marks, deforming the concave or convex recording marks, or altering a pattern of the concave or convex recording marks;
• the second sub information is generated by scrambling the predetermined information that is the same for the predetermined units based on the first sub information:
• the second sub information is recorded as being superimposed on the main information by changing a reflectivity of the reflective film formed on the concave or convex recording marks;
• and
• when the second sub information is generated based on the first sub information recorded in a first predetermined unit of the predetermined units, the second sub information is recorded in a second predetermined unit that is continuous to and follows the first predetermined unit in a direction of the track.

An optical disc playback apparatus arranged to play an optical disc, the optical disc being recorded with main information that is to be decrypted using predetermined information recorded based on first sub information and second sub information, the main information being recorded in predetermined units each including at least address information by arranging concave or convex recording marks on a spiral track, the first sub information being recorded by shifting the concave or convex recording marks, deforming the concave or convex recording marks, or altering a pattern of the concave or convex recording marks, the apparatus comprising:

• a main information reading unit configured to irradiate the concave or convex recording marks with laser light and read the main information based on a reflected light element corresponding to the concave or convex recording marks included in reflected light of the laser light;
• a first sub information detection unit configured to detect the first sub information recorded so as to correspond to each unit of the main information that has been divided in the predetermined units;
• a first sub information storing unit configured to store the first sub information detected for each of the predetermined units;
• a second sub information reading unit configured to read, for each of the predetermined units, the second sub information generated by scrambling based on the first sub information, in accordance with a change in a reflection intensity that differs from a reflection intensity of the reflected light element corresponding to the concave or convex recording marks included in the reflected light;
• and
• a testing unit configured to descramble the second information generated by scrambling using the first sub information stored in the first sub information storing unit,
• wherein the first sub information detection unit detects the first sub information that differs for each of the predetermined units;
• and
• the testing unit uses the first sub information detected in a first predetermined unit of the predetermined units to descramble the second sub information recorded in a second predetermined unit of the predetermine units that is continuous to and follows the first predetermined unit in a direction of the track.

An optical disc playback apparatus arranged to play an optical disc, the optical disc being recorded with main information that is to be decrypted using predetermined information recorded based on first sub information and second sub information, the main information being recorded in predetermined units each including at least address information by arranging concave or convex recording marks on a spiral track, the first sub information being recorded by shifting the concave or convex recording marks, deforming the concave or convex recording marks, or altering a pattern of the concave or convex recording marks, the apparatus comprising:

• a main information reading unit configured to irradiate the concave or convex recording marks with laser light and read the main information based on a reflected light element corresponding to the concave or convex recording marks included in reflected light of the laser light;
• a second sub information reading unit configured to read the second sub information based on a change in a reflection intensity that differs from a reflection intensity of the reflected light element corresponding to the concave or convex recording marks included in the reflected light;
• a testing unit configured to detect information associated with the first sub information from the second sub information;
• and
• a first sub information detection unit configured to read the first sub information, detect a correlation between the read first sub information and the information associated with the first sub information, and output the predetermined information that is to decrypt the main information based on a result of the detection.

An optical disc manufacturing apparatus arranged to record second sub information onto an optical disc, the optical disc including first sub information and main information that is recorded by arranging concave or convex recording marks on a spiral track, recorded in predetermined units each including at least address information, and is to be decrypted using predetermined information, the apparatus comprising:

• a first sub information detection unit configured to detect the first sub information by detecting a shift of the concave or convex recording marks, a deformation of the concave or convex recording marks, or an alteration of a pattern of the concave or convex recording marks for each unit of the main information that has been recorded as being divided in the predetermined units;
• a first sub information storing unit configured to store the first sub information detected for each of the predetermined units;
• and
• a second sub information recording unit configured to generate the second information by scrambling the predetermined information that is the same for the predetermined units based on the first sub information stored in the first sub information storing unit, and record the second sub information by controlling an intensity of laser light with which a reflective film formed on the concave or convex recording marks of the optical disc is irradiated,
• wherein the first sub information detection unit detects the first sub information that differs for each of the predetermined units;
• and
• the second sub information recording unit generates the second sub information by scrambling the predetermined information based on the first sub information recorded in a first predetermined unit of the predetermined units and records the second sub information in a second predetermined unit of the predetermined units that is continuous to and follows the first predetermined unit in a direction of the track.

An optical disc recorded with main information that is to be decrypted using predetermined information by arranging concave or convex recording marks on a spiral track and having a reflective film formed on the concave or convex recording marks,

• wherein
• the main information is recorded in predetermined units each including at least address information and being arranged continuous to one another in a direction of the spiral track;
• the predetermined information is recorded based on first sub information and second sub information;
• the first sub information is generated by scrambling the predetermined information that is the same for the predetermined units based on a predetermined value that differs for each of the predetermined units;
• the first sub information is recorded as being superimposed on the main information by shifting the concave or convex recording marks, deforming the concave or convex recording marks, or altering a pattern of the concave or convex recording marks;
• the second sub information is generated based on the predetermined value that differs for each of the predetermined units;
• the second sub information is recorded as being superimposed on the main information by changing a reflectivity of the reflective film formed on the concave or convex recording marks;
• and
• the second sub information recorded in a first predetermined unit of the predetermined units and the first sub information recorded in a second predetermined unit that is continuous to and follows the first predetermined unit in a direction of the track are generated and recorded based on the same predetermined value.