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:
Jun. 05, 2001
Filed:
Sep. 08, 1998
Norichika Mine, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A WBBM is recorded in a lead-in area of a rewritable disc. The WBBM is a bit map that represents whether each block that is a record/reproduction data unit is a recorded block or a non-recorded block. A finalizing process for recording dummy data in the vicinity of a recorded block is performed so that a read-only disc drive can seek a block and a servo operation of the drive can be stable. At this point, with reference to the WBBM, the efficiency of the process can be improved. When a plurality of WBBMs are ring-structured and the WBBMs are successively updated, the write operation can be prevented from being concentrated to the same area. In addition, a destroyed WBBM due to a power failure or the like can be restored. The value of an update counter represents the latest WBBM.