| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk device which can record information on an optical disk so that other optical disks other than the specific optical disk can not read the information. SOLUTION: The optical disk device comprises: an EFM modulation means 2 to produce EFM modulated information by EFM-modulating digital information; a secondary modulation means 4 to form secondary modulated information by secondarily modulating the EFM modulated information so as to change a length or an array of a part of pits or lands defined by the EFM modulated information 2 according to a predetermined rule; and a recording means to form pits on the optical disk W based on the secondary modulated information 4. COPYRIGHT: (C)2007,JPO&INPIT
|
