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:
Aug. 20, 1996
Filed:
Mar. 31, 1995
John E Kulakowski, Tuscon, AZ (US);
Judson A McDowell, Tuscon, AZ (US);
Kurt A Rubin, Santa Clara, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention provides efficient management of calibration and spare sectors on a banded optical write-once, read-many (WORM) disk. A portion of each band on the disk includes a user data area and a reserved area. Sectors in the reserved area are usable either as spare sectors, replacing defective sectors in the user area, or as calibration sectors, for use when the laser write-power level is calibrated. Sectors preferably are used for sparing from one end of the reserved area while sectors are used for calibration from the opposite end. A common overflow reserved area can also be provided for use if all of the sectors in one or more primary reserved areas associated with any of the bands have been exhausted.