US Patent 7512846 Method and apparatus of defect areas management

A method and the apparatus of defect areas management includes the steps as following: reading a defect area table in a random access memory; if the area is readable, then read the area. If the area is not accessible, then label and add one count in the defect area table of inability to read of the defect area, and else if the count of inability to read of the defect area is more than a predetermined value, then the defect area is defined as the area of being not to be read again. Then the defect area of being not to be read again is skipped and not to be read the next time in order to decrease the total access time.