Back to results
US 5,233,576 AGranted
Multi-function optical disk drive and media
AssigneeHewlett-Packard Company
InventorsHoyle L. Curtis, Terry L. Loseke
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeHewlett-Packard Company
InventorsHoyle L. Curtis, Terry L. Loseke
Estimating the term…
Disclosed is an apparatus and method for defining magneto-optical disk media and an optical data storage device that allows the media to be convertible from writable to read-only. The media has a media descriptor table contained within a control track which is modified to define the media as a new media type. Previously manufactured drives will not recognize the media type, and therefore, will not read or write the media, so the data on the media is protected from being destroyed by such drives. The invention also defines a storage state bit within each sector of each track of the media, that defines whether the sector is writable or read-only. With this bit set into the writable state, the sector can be written many times. Once the bit is changed to read-only, however, the sector can no longer be written. The data storage device of the invention will not reset the bit, once it is set to the read-only state. The invention defines two locations for the storage state bit. In one embodiment of the invention the storage state bit is located in the sector mark field area of each sector, prior to the data portion of the sector. In a second embodiment of the invention, the storage state bit is placed in the data field area of each sector. Using the above described apparatus and method, the invention provides the same level of security as current WORM drives.
A system for using a control track on a rewritable data storage media, said control track being defined by International Standards Organization Standard Number 10089, to define said rewritable data storage media as a write-once data storage media, and for storing data thereon, said system comprising:
A process for defining a rewritable media, said media being defined by International Standards Organization Standard Number 10089, as write-once using a control track, said control track being defined in said Standard Number 10089, and for storing data thereon, said process comprising the steps of:
Dependencies are inferred from the claim text.