SMALL CARTRIDGE FREE OPTICAL DISC WITH HIGH LEVEL OF REDUNDANCY AND TOLERANCE FOR MISSING DATA

摘要

In the invention, e-book information is distributed on un-cartridged small media that can be made cheaply enough for use in free distribution of information. The e-book information is encoded and stored on a read-only optical disc that is 2 to 4 cm in diameter and .6 to 1.2 mm thick, the information being encoded with sufficient redundancy and sufficient tolerance for missing information that the disc can be conveniently handled and pocketed without losing reliability of information access. The disc has a lead-in area that is prior to all the e-book information and that contains a disc navigation area, and a lead-out area that follows all the e-book information. The disc may include multiple partitions, each partition containing sufficient access information for independent access of the e-book information within the partition without accessing any other partition. Alternatively, the disc may include multiple slots for files and that are equally spaced. For example, to provide data redundancy, at least some of the partitions are duplicate partitions that contain all the same data as another duplicate partition, and the disc navigation area contains partition descriptors that indicate all the partitions and the areas allocated to each of the partitions, and the disc also includes duplicates of the partition descriptors, the duplicate partition descriptors being stored in the lead-in area or in the lead-out area to provide redundancy of navigation information.