Method of recording and reproducing digital information and apparatus therefor

DETAILED DESCRIPTION It is an object of the present invention to solve the above-mentioned prior art problems and provide a method and apparatus for recording and reproducing digital information wherein the transfer rate is made higher through a higher recording density.
As the recording film of a digital information recording medium, a material permitting a multiple light-wavelength recording is used.
A light beam guide track made of a series of pre-pits is prepared on the recording film on which information bits are recorded or reproduced by a recording/reproducing light beam.
The series of pre-pits are respectively spaced apart by a distance or interval longer than the length of an information bit in the track direction.
The PHB phenomenon is used for recording on and reproducing from an information recording medium.
The pre-pit on the recording film is used as a synchro mark.
The wavelength of the recording/reproducing light beam is sequentially varied while scanning by one pitch between pre-pits, so that information bits associated with the recording/reproducing light beams of different wavelengths are formed interposing upon each other.
Each pre-pit is used as a basis of discriminating what wavelength of the recording/reproducing light beam was used for each information bit formed on the recording film.
Therefore, information readout from each information bit during reproducing can always be performed using a correct wavelength of the recording/reproducing light beam.
Information contents can be recorded which contents are obtained by further sampling information signals during a sampling period during which an information content between the adjacent bits recorded by a same wavelength of the recording/reproducing light beam is sampled.