Patents Assigned to Denon Digital LLC
  • Method for making copy protected optical discs
    Patent number: 6646967
    Abstract: A machine-non-readable defect is formed on a CD-ROM by re-modulation of a master cutting laser beam recorder. Re-modulation in specific program areas creates non-readable marks which interfere with any attempt to image-copy the CD-ROM. The non-machine-readable marks can be followed by valid data which may be used as keys to verify the authenticity of the CD-ROM. The machine-non-readable defect is invisible to the human eye to thwart detection and subsequent reverse engineering attempts.
    Type: Grant
    Filed: August 12, 1997
    Date of Patent: November 11, 2003
    Assignee: Denon Digital LLC
    Inventor: Ben Garcia