| 摘要 |
PROBLEM TO BE SOLVED: To provide a data recording method and device, a data recording medium, and a data reproducing method and device which can readily perform the control free from intentionally inserting defects in the data recording method and device, the data recording medium, and the data reproduction method and device, etc. applied to a read-only-memory (ROM) type optical disk. SOLUTION: Main data and sub-codes from input terminals 1a, 1b are processed by encoders 2a, 2b, respectively and are supplied to an EFM modulation section 4 via a multiplexer 3. An 8-4 modulation section 4 comprises a 8-14 conversion section 5a and a connection bit selection section 5b. A DSV normal control 7a and a DSV special control 7b are prepared with respect to the 8-14 EMF modulation section 4. The DSV special control is performed only in a predetermined zone set, in advance, on an optical disk. The DSV special control is controlled in a direction of increasing the DSV absolute value to such an extent that the risk to prevent normal data reproduction occurs. The normal control is a control in a direction of making the DSV absolute value converge to 0. At reproduction, it is decided as being an original disk, based on the reproduction situation in the predetermined zone being abnormal. The key of encryption is recordable in the predetermined zones. Therefore, copy protection is performed effectively. COPYRIGHT: (C)2005,JPO&NCIPI |
