Method and apparatus for determining if an optical disk originated from a valid source
A method and apparatus for determining if an optical disk originated from a valid source, the method and apparatus scanning one major surface of the optical disk for imperfections, storing the locations of the imperfections relative to a datum, comparing a parameter of each of the locations of the imperfections with corresponding parameters of a master disk of known source for determining if the disk originated from the source from which the master disk originated.
1. A method for determining if media originated from a valid source, the method comprising the steps of:
scanning a surface of the media for imperfections;
storing the locations of the imperfections relative to a datum, wherein locations of the imperfections are coordinates relative to the media;
comparing a parameter of each of the locations of the imperfections with corresponding parameters of a master media of known source for determining if the media originated from the source from which the master media originated.
2. The method according to claim 1 , wherein the media is an optical disk and the surface of the disk which is scanned is a surface through which laser light is passed to the reflective surface for reading recorded data on the optical disk.
3. The method according to claim 1 , wherein light reflected from imperfections on the surface is reflected to a camera.
4. The method according to claim 1 , wherein locations of the imperfections are stored by respective X-Y coordinates relative to the datum, and the X-Y coordinates are subsequently converted into angular co-ordinates of the disk.
5. An apparatus for determining if media originated from a valid source, the apparatus comprising:
a scanning means for scanning a surface of the media for detecting imperfections;
a computing means for computing the location of each surface imperfection;
a secondary storing means for storing the locations of the surface imperfections; and
a means for providing access to a primary storing means which stores parameters of locations of surface imperfections of master media from known sources;
and a comparing means for comparing parameters of the media being scanned with corresponding parameters of the master media for determining if the media originated from a valid source.
6. The apparatus according to claim 5 , wherein the scanning means comprises a platform capable of planar movement in X-Y directions, and a camera for capturing images of surface imperfections.