Information reproducing method comprising the step of preparing a defect bit map and a defect index table
AssigneeCanon Kabushiki Kaisha
InventorMasahiro Tamegai
Life of this patent
Estimating the term…
Abstract
In an information reproducing method, directory data for managing file data is recorded on an information recording medium to manage recording reproduction of the file data. There are provided a defect bit map in which defect information indicating if a defect exists or not corresponding to each physical address of the recording medium is recorded on the recording medium, and a defect index table on which the number of defects in a block is recorded every predetermined block of the defect bit map. When a designated logical address is converted into a physical address, searching is sequentially performed on a block on the defect index table where the designated logical address exists and a physical address in the searched block on the defect bit map.
Claims11
An information reproducing method for an information recording medium storing file data and directory data for managing the file data, comprising the steps of:
- the recording medium representing whether each physical address is defective, the defect information including the number of spread physical sectors and the number of management information recorded physical sectors;
- preparing a physical defect index table storing the total defect number of each predetermined block on the defect bit map;
- searching a block where a desired logical address exists on the basis of the physical defect index table;
- and
- searching a physical address corresponding to the desired logical address in the searched block on the physical defect bit map.
An information reproducing method reproducing information from an information medium having a data region for recording data and a directory region for recording a directory for managing the data, comprising the steps of:
- reading the directory prior to reproduction of the data;
- preparing, on the basis of defect information of the read directory, a physical defect bit map corresponding to each physical address of the recording medium if the physical address is defective;
- preparing a physical defect index table representing the number of effects in each predetermined block on the physical defect bit map;
- preparing a logical defect bit map corresponding to a logical address managed by an inaccessible directory and other logical addresses when the inaccesssible directory exists, and recording defect information on the bit map corresponding to the logical address in a logical region managed by the inaccessible directory;
- checking if the logical address is defective with reference to the logical defect bit map when information at the designated logical address is to be read;
- and
- when the designated logical address is not defective, searching the physical defect index table and physical defect bit map to convert the designated logical address in to a physical address.
A method of reproducing information from a write once information recording medium having a data portion for recording a file comprising a plurality of physical sectors, and a sector management portion for managing physical sectors of the file if each physical sector of the data portion is defective, comprising steps of:
- reading the sector management portion and preparing therefrom a defect bit map representing whether each sector is defective by causing one sector to correspond to one bit, the defect bit map comprising information concerning the number of spread physical sectors and the number of management information recorded physical sectors;
- and
- preparing a defect index table representing the number of physical defects on a predetermined number of physical sectors.
A method for preparing a defect bit map and a defect index table used for converting a logical address into a physical address, comprising the steps of:
- preparing a defect bit map storing defect information corresponding to each physical address of a recording medium if the physical address is defective;
- preparing, for every predetermined block of the defect bit map, a defect index table storing the number of defects within the block;
- storing the number of physical sectors managed by said defect bit map in said defect bit map as the number of spread physical sectors;
- and
- storing the number of physical sectors of sector management information which is recorded on the recording medium as a directory in said defect bit map as the number of management information recorded physical sectors.
Dependencies are inferred from the claim text.