The present invention relates to an information recording medium, the contents of which can be played back by a plurality of types of information playback apparatuses provided by different manufacturers or distributors. The present invention also relates to an information recording method and apparatus for recording information on such information recording medium. Furthermore, the present invention relates to an information playback method and apparatus for playing back information recorded on such information recording medium.
In recent years, optical discs as information recording media have been extensively studied and developed. Optical discs include a CD (Compact disc) that has prevailed, and a DVD (Digital Video disc) that has a large storage size. The DVD includes a DVD-Video that can record/play back video information. The formats of information recorded on information recording media such as a CD, DVD, and the like are specified by standards described in standard books. The manufacturers of information recording media record information formatted according to the standards on information recording media.
Information recording/playback apparatuses that record information on information recording media and play back information recorded on the information recording media are manufactured by a plurality of manufacturers. However, as described above, since information is recorded on the information recording medium according to the standards, similar playback results are obtained irrespective of the manufacturers of information recording/playback apparatuses. That is, information recording/playback apparatuses can neither differentiate functions nor provide their originality. As a result, the principle of competition of the manufacturers does not work in term of functions, and technical development in the DVD-Video market may be disturbed.
Since information is recorded on an information recording medium according to fixed standards, functions cannot be quickly expanded in correspondence with advances of technologies. That is, in order to add a new function to an information recording medium, the standards must be upgraded in correspondence with the new function to be added. However, since much time is required for upgrading the standards, it is hard to add new functions in quick response to the advances of technologies.