Optical recording medium and manufacturing method thereof

An optical recording medium having an information data recording region including groove tracks and land tracks formed in alternation, each of said groove tracks carrying thereon a sequence of alternately appearing mark portions and space portions, said sequence representing an information data signal, and said land tracks being formed with a prepit train including at least one prepit which carries pre-information every predetermined data unit of said groove tracks, wherein:

• at least a portion of said groove tracks comprises a plurality of groove portions separated by groove-absent portions in a rotational direction of said optical recording medium, each of said mark portions or each of said space portions includes one of said groove-absent portions, and
• at least one of two groove tracks adjacent to said prepit train has a continuous groove portion extending at least from a leading end to a trailing end of at least one prepit included in said prepit train in a rotational direction of said optical recording medium.

An optical recording medium having an information data recording region including groove tracks and land tracks formed in alternation, each of said groove tracks carrying thereon a sequence of alternately appearing mark portions and space portions, said sequence representing an information data signal, and said land tracks being formed with a prepit train including at least one prepit which carries pre-information every predetermined data unit of said groove tracks, wherein:

• at least a portion of said groove tracks comprises a plurality of groove portions separated by groove-absent portions in a rotational direction of said optical recording medium, each of said mark portions or each of said space portions includes one of said groove-absent portions, and
• at least one of two groove tracks adjacent to said prepit train has a continuous groove-absent portion extending at least from a leading end to a trailing end of at least one prepit included in said prepit train in a rotational direction of said optical recording medium.

An optical recording medium having an information data recording region including groove tracks and land tracks formed in alternation, each of said groove tracks carrying thereon a sequence of alternately appearing mark portions and space portions, said sequence representing an information data signal, and said land tracks being formed with a prepit train including at least one prepit which carries pre-information every predetermined data unit of said groove tracks, wherein:

• at least a portion of said groove tracks comprises a plurality of groove portions separated by groove-absent portions in a rotational direction of said optical recording medium, each of said mark portions or each of said space portions includes one of said groove-absent portions,
• one of two groove tracks adjacent to said prepit train has a continuous groove portion extending at least from a leading end to a trailing end of at least one prepit included in said prepit train in a rotational direction of said optical recording medium, and
• another groove track of said two groove tracks adjacent to said prepit train has a continuous groove-absent portion extending at least from a leading end to a trailing end of at least one prepit included in said prepit train in a rotational direction of said optical recording medium.

A method of manufacturing an optical recording medium having an information data recording region, comprising the steps of:

• forming groove tracks carrying thereon a sequence of alternately appearing mark portions and space portions, said sequence representing an information data signal, and
• forming land tracks, in alternation with said groove tracks, having a prepit train including at least one prepit which carries pre-information every predetermined data unit of said groove tracks, wherein:
• the step of forming groove tracks includes a step of forming a plurality of groove portions, at least in a portion of said groove tracks, separated by groove-absent portions in a rotational direction of said optical recording medium, each of said mark portions or each of said space portions includes one of said groove-absent portions.

A method of manufacturing an optical recording medium having an information data recording region, comprising the steps of:

• forming groove tracks carrying thereon a sequence of alternately appearing mark portions and space portions, said sequence representing an information data signal, and
• forming land tracks, in alternation with said groove tracks, having a prepit train including at least one prepit which carries pre-information every predetermined data unit of said groove tracks, wherein:
• the step of forming groove tracks includes a step of forming a plurality of groove portions, at least in a portion of said groove tracks, separated by groove-absent portions in a rotational direction of said optical recording medium, each of said mark portions or each of said space portions includes one of said groove-absent portions, and at least one of two groove tracks adjacent to said prepit train has a continuous groove portion extending at least from a leading end to a trailing end of at least one prepit included in said prepit train in a rotational direction of said optical recording medium.

A method of manufacturing an optical recording medium having an information data recording region, comprising the steps of:

• forming groove tracks carrying thereon a sequence of alternately appearing mark portions and space portions, said sequence representing an information data signal, and forming land tracks, in alternation with said groove tracks, having a prepit train including at least one prepit which carries pre-information every predetermined data unit of said groove tracks, wherein:
• the step of forming groove tracks includes a step of forming a plurality of groove portions, at least in a portion of said groove tracks, separated by groove-absent portions in a rotational direction of said optical recording medium, each of said mark portions or each of said space portions includes one of said groove-absent portions, and at least one of two groove tracks adjacent to said prepit train has a continuous groove-absent portion extending at least from a leading end to a trailing end of at least one prepit included in said prepit train in a rotational direction of said optical recording medium.