Method of producing file management structures, information reproduction apparatus and information reproducing method

A method for reproducing information from an information recording medium, said information recording medium including a data area for recording data files, a plurality of file management information for recording a plurality of file management information having data structures different from each other for managing positions of the data files, unused areas and defective areas, and a discrimination area for recording discrimination data, position data of each of the plurality of file management information areas and a position data of the data area, wherein each of the file management information is produced by assuming that the data area is assigned continuously next after the file management information area recording with the file management information in the information recording medium., said method comprising:

• reading a position data of the data area from the discrimination area;
• determining position data of a particular file management information area by using the discrimination data recorded in the discrimination area and reading the position data from the discrimination area;
• converting a first data reproducing position to a second data reproducing position in the information recording medium by using the position data of the data area and the position data of the particular file management information area after determining the first data reproducing position when said data area is assigned continuously after said file management information area;
• and
• reproducing data from the converted, second data reproducing position.

An information reproduction apparatus for reproducing information from an information recording medium, said information recording medium including a data area for recording data files, a plurality of file management information areas for recording a plurality of file management information having data structures different from each other for managing positions of the data files, unused areas and defective areas, and a discrimination area for recording discrimination data and position data of each of the plurality of file management information areas and position data of the data area, said information reproduction apparatus being connected to a host computer and comprising:

• position acquisition means for reproducing and saving in a memory means the position information from the discrimination area when a position acquisition instruction is received from the host computer, said position information including position data of the data area and position data of a file management information area in correspondence to the discrimination data described in the position acquisition instruction;
• reproducing position conversion means for reading the position information from said memory means and for converting a data reproducing position contained in a data reproduction instruction received from the host computer by using the position information;
• and
• data reproduction means for reproducing data from said data reproducing position designated by the reproducing position conversion means and for sending the reproduced data to the host computer.