Write protect for rewritable compact disks and digital video disks
View Patent ↗A method and apparatus for write protection of rewritable compact disks and digital video disks. A Power Calibration Area is covered to prevent the drive laser from completing a calibration procedure. In one embodiment, the disk has an indented area formed around the central hole in the disk. A ring shaped plug is inserted into the indented area, with an extended surface that covers the calibration area. In an alternative embodiment, an adhesive label, ink, dye or paint is used. In still another alternative embodiment, the calibration area is mechanically abraded to provide permanent write protection. Finally, the laser in the drive may be used to darken, damage or destroy the calibration area or a transparent label over the calibration area, for permanent write protection.
1. An apparatus for write protection of a disk, the disk having a power calibration area and a data area, the apparatus comprising:
a ring capable of being attached to the disk, the ring having a portion that covers the power calibration area but not the data area.
2. The apparatus of claim 1 , the disk having a central hole and an indented area formed around the hole, the ring adapted for insertion into the indented area.
3. The apparatus of claim 1 , the ring comprising an adhesive label.
4. The apparatus of claim 1 , the ring being transparent initially, and then darkened by exposure to a laser.
5. An apparatus for write protection of a disk, the disk having a central hole and a power calibration area, the apparatus comprising:
a holder adapted to fit into the central hole of the disk; and
an abrasive tool, rotating around the holder, adapted to abrade the power calibration area when rotated.
6. A method of write protection for a disk, the disk having a power calibration area for a laser and a data area, the method comprising:
shielding the power calibration area, but not the data area, of the disk from light sufficiently to prevent a disk drive from using the power calibration area to calibrate a laser.
7. The method of claim 6 , the disk adapted to receive light from a laser having a particular wavelength, the step of shielding further comprising:
covering the power calibration area with a material that is non-transparent at the particular wavelength.
8. The method of claim 7 , the material comprising an adhesive label.
9. The method of claim 7 , the material comprising an ink.
10. The method of claim 7 , the material comprising a dye.
11. The method of claim 7 , the material comprising a paint.