Optical disc and optical disc reproducing apparatus

An apparatus for reproducing digital data recorded on an optical disc as a plurality of data pits whose edge positions are shifted according to a multi-level pit edge recording method, the optical disc comprising a substrate member and a plurality of tracks formed on the substrate member, a plurality of data areas and a plurality of reference areas being formed on the substrate member such that each of the data areas and the reference areas is formed continuously over the plurality of tracks, the data pits corresponding to the digital data being recorded on the tracks in each of the data areas according to the multi-level pit edge recording method, tilt reference pits which are used as a reference for detecting a tilt of the optical disc relative to a direction of a light beam which is emitted to the optical disc to reproduce the digital data being recorded on the tracks in each of the reference areas, the apparatus comprising:

• a reading device that reads the data pits from the optical disc by emitting the light beam to the optical disc and generates a reproduction signal indicating the edge positions of the data pits;
• a tilt detecting device that detects the tilt of the optical disc on the basis of the tilt reference pit, and generates tilt error signal indicating the tilt;
• and
• a tilt compensating device that reduces an influence of the tilt of the optical disc on the basis of the tilt error signal.