Reading method and apparatus for an information recording medium and spare area allocation thereof

Abstract

A reading apparatus for reading an information recording medium is provided. The information recording medium has a user data area for recording data and a spare area for recording replacements corresponding to registered defects of the user data area. The reading apparatus comprising a first storage device for storing the data read from the user data area, a second storage device for storing replacements, and a replacement controller for searching a corresponding replacement in the second storage device when a registered defect is found in the user data area, while reading the corresponding replacement and neighboring replacements thereof from the spare area of the information recording medium and storing the read replacements into the second storage device when the corresponding replacement is failed to be found in the second storage device.

1 . A reading apparatus for reading an information recording medium having a user data area for recording data and a spare area for recording replacements corresponding to registered defects of the user data area, said apparatus comprising:
 a first storage device for storing the data read from the user data area;   a second storage device for storing replacements; and   a replacement controller for searching a corresponding replacement in the second storage device when a registered defect is found in the user data area, while reading the corresponding replacement and neighboring replacements thereof from the spare area of the information recording medium and storing the read replacements into the second storage device when the corresponding replacement is failed to be found in the second storage device.   
     
     
         2 . The apparatus as claimed in  claim 1 , wherein at least a portion of the replacements stored in the second storage device are cleared if the corresponding replacement for the defect is failed to be found in the second storage device. 
     
     
         3 . The apparatus as claimed in  claim 1 , wherein the replacement controller determines a range of the neighboring replacements based on a built-in predetermined algorithm. 
     
     
         4 . The apparatus as claimed in  claim 1 , wherein the replacement controller determines a range of the neighboring replacements according to at least one of the parameters selected from a group consisting essentially of location relationship between the defect and the corresponding replacement, performance of the reading apparatus, reading mode, and condition of the information recording medium. 
     
     
         5 . The apparatus as claimed in  claim 1 , wherein the replacement controller accumulates registered defects found in the user data area; and searches the corresponding replacements recorded in the spare area for the accumulated registered defects. 
     
     
         6 . The apparatus as claimed in  claim 5 , wherein the replacement controller searches the replacements whenever the number of the accumulated registered defects reaches a predetermined value.