Recording medium and apparatus and method for manufacturing the same

A method of manufacturing a recording medium having pairs of groove tracks and land tracks having periodically formed bent portion provided side by side on a substrate, a plurality of land prepits previously formed on said land tracks and carrying information about said groove tracks, and a recording layer formed on at least said groove tracks and said land tracks, said method comprising the steps of:

• forming said groove tracks by irradiating a spot of a cutting light beam, which moves relatively to a recording master disc, on a photoresist layer formed on said recording master disc;
• and
• increasing an intensity of said cutting light beam and simultaneously shifting said spot of said cutting light beam in a direction perpendicular to a direction in which said groove tracks extend, returning said shifted spot to a position where said groove tracks should extend, thereby forming said land prepits having sides defined by curved surfaces continuously extending from sides of said groove tracks, and making sides of said groove tracks which face said sides of said land prepits having curved surfaces that stricture said groove tracks to make a depth of the land prepit larger than that of the groove track.

An apparatus for manufacturing a recording medium having pairs of groove tracks and land tracks having periodically formed bent portion provided side by side on a substrate, a plurality of land prepits previously formed on said land tracks and carrying information about said groove tracks, and a recording layer formed on at least said groove tracks and said land tracks, said apparatus comprising:

• a track forming section for forming said groove tracks by irradiating a spot of a cutting light beam, which moves relatively to a recording master disc, on a photoresist layer formed on said recording master disc;
• and
• a land-prepit forming section for increasing an intensity of said cutting light beam and simultaneously shifting said spot of said cutting light beam in a direction perpendicular to a direction in which said groove tracks extend, returning said shifted spot to a position where said groove tracks should extend, thereby forming said land prepits having sides defined by curved surfaces continuously extending from sides of said groove tracks, and making sides of said groove tracks which face said sides of said land prepits having curved surfaces that stricture said groove tracks to make a depth of the land prepit larger than that of the groove track.