Abstract: An information recording medium for reproducing information by irradiation with a laser beam condensed by an objective lens with a numerical aperture NA includes a disk-shaped substrate and a recording layer disposed on the substrate. On the surface of the substrate, a plurality of prepit regions and a plurality of data regions are disposed alternately along spiral or concentric virtual track centers. Each prepit region includes a pair of wobble pits for tracking servo, and a length L (?m) of the wobble pit along the virtual track center, a wavelength ? (?m) of the laser beam, and a numerical aperture NA satisfy a relationship: 0.3?L. NA/??0.65.

Abstract: A recording medium which has a high effective recording density and a high error correcting capability, and a recording apparatus and a reproducing apparatus for the same are provided. The recording apparatus comprises an encoding unit, which encodes input data by an encoding scheme including a run length limit encoding scheme to thereby generate encoded data and divide and output one data stream formed by said encoded data into a plurality of data blocks, and a data adding unit which adds data having the same value as the last one bit of encoded data of said precedent data block to the top of at least one of said data blocks. Using the recording apparatus, in each data recording area of a recording medium which comprises pre-pit areas and a plurality of data recording areas which are divided by said pre-pit areas, a data block which contains said added data is recorded.

Abstract: An information recording medium for reproducing information by irradiation with a laser beam condensed by an objective lens with a numerical aperture NA includes a disk-shaped substrate and a recording layer disposed on the substrate. On the surface of the substrate, a plurality of prepit regions (110) and a plurality of data regions (120) are disposed alternately along spiral or concentric virtual track centers. Each prepit region includes a pair of wobble pits (113) for tracking servo. and a length L (&mgr;m) of the wobble pit along the virtual track center, a wavelength &lgr; (&mgr;m) of the laser beam, and a numerical aperture NA satisfy a relationship: 0.3≦L.NA/&lgr;≦0.