摘要:
An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T-14T (T=0.133 μm) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.
摘要:
An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T-14T (T=0.133 μm) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.
摘要:
An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T–14T (T=0.133 μm) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.
摘要:
An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T-14T (T=0.133 μm) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.
摘要:
An optical disc includes a processed area that has been processed by the irradiation of a YAG laser. Concave pits and convex pits having a length 3T–14T (T=0.133 μm) are formed in an area of the optical disc other than the processed area. The processed area includes (1) a concave pit having a length X or (2) a pit string that has a length X and includes a convex pit from which a reflection layer has been removed. A specific area of the optical disc records physical character information that shows the location and length of the concave pit or the pit string in the processed area.
摘要:
An optical disk is provided for recording data of a signal modulated according to a predetermined modulation method in a form of concavo-convex pits. The optical disk includes a first area having a reflecting film partly removed, and a second area for recording pits which are different from pits satisfying requirements of the predetermined modulation method. The first area having the reflecting film partly removed includes a portion which is formed by removing the reflecting film, and has a length longer than a maximum pit length determined by the modulation method in a circumferential direction of the optical disk. When the pits recorded on the optical disk are physically copied as they are, physical copying of the optical disk can be prevented by utilizing such a difference that the authorized optical disk differs from a pirated copy in a combination of the respective reproduced signals of the first and second areas.
摘要:
An optical disk is provided for recording data of a signal modulated according to a predetermined modulation method in a form of concavo-convex pits. The optical disk includes a first area having a reflecting film partly removed, and a second area for recording pits which are different from pits satisfying requirements of the predetermined modulation method. The first area having the reflecting film partly removed includes a portion which is formed by removing the reflecting film, and has a length longer than a maximum pit length determined by the modulation method in a circumferential direction of the optical disk. When the pits recorded on the optical disk are physically copied as they are, physical copying of the optical disk can be prevented by utilizing such a difference that the authorized optical disk differs from a pirated copy in a combination of the respective reproduced signals of the first and second areas.
摘要:
An optical disc storing a copyrighted digital product has a data area in which N processed parts are provided in order to certify that the stored digital product is an original one. A BCA provided on the optical disc stores judgment criteria information as well as N pieces of physical feature information. The judgment criteria information includes a numeric value N being the total number of processed parts, and a numeric value M being an integer between 0 and N inclusive and representing the security level to be assured for the digital data stored. When a numeric value P being the total number of processed parts in a normal state exceeds the numeric value M, a reproduction device reproduces the optical disc. When the numeric value P falls short of the numeric value M, the reproduction device does not reproduce the optical disc.
摘要:
An information recording medium includes a plurality of sectors each of which has a sector header area storing a unique sector number and a data storage area for storing user data. User data to be recorded onto the information recording medium is scrambled using a data scramble key generated from a unique medium identifier of the information recording medium and a sector number of a sector into which the user data is to be recorded. The medium identifier used here has been scrambled using a medium identifier scramble key generated from predetermined data and a sector number of a sector into which the medium identifier is to be stored, and stored in that sector. In so doing, security is ensured not only for each individual information recording medium but also for each individual sector, with it being possible to protect data recorded on the information recording medium against unauthorized reproduction.
摘要:
An optical disk is provided for recording data of a signal modulated according to a predetermined modulation method in a form of concavo-convex pits. The optical disk includes a first area having a reflecting film partly removed, and a second area for recording pits which are different from pits satisfying requirements of the predetermined modulation method. The first area having the reflecting film partly removed includes a portion which is formed by removing the reflecting film, and has a length longer than a maximum pit length determined by the modulation method in a circumferential direction of the optical disk. When the pits recorded on the optical disk are physically copied as they are, physical copying of the optical disk can be prevented by utilizing such a difference that optical disk differs from a pirated copy in a combination of the respective reproduced signals of the first and second areas.