The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 26, 2005
Filed:
Mar. 25, 1997
Lawrence N Taugher, Loveland, CO (US);
Lawrence N Taugher, Loveland, CO (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
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.