Data recording medium and record/playback apparatus using the data recording medium

A recording apparatus comprising means for recording data on a disk-shaped data recording medium on which an amount of data is to be recorded, comprising:

• at least a first and a second recording layers;
• a first recording direction from the inner side to the outer side of said medium and a second recording direction from the outer side to the inner side of said medium being determined as directions for recording data;
• one of said first and second recording directions being used as the recording direction of said first recording layer;
• the other of said first and second recording directions being used as the recording direction of said second recording layer;
• each of said recording layers including a data area in which data has a sector structure, and each sector containing a least a layer number for identifying said first recording layer and said second recording layer;
• and
• wherein substantially one half of said amount of data to be recorded on said medium is recorded to a predetermined data area in said data area of said first recording layer, said predetermined data area being smaller than said data area available for recording the data, and the remainder of the data is recorded in said data area of said second recording layer such that a start position of the data in one of said first and second recording layers is substantially at the same radial position as a final position of the data in the other of said first and second recording layers.

A playback apparatus comprising means for reproducing data from a disk-shaped data recording medium on which an amount of data was previously recorded, comprising:

• at least a first and a second recording layers;
• a first recording direction from the inner side to the outer side of said medium and a second recording direction from the outer side to the inner side of said medium being determined as directions for recording data;
• one of said first and second recording directions being used as the recording direction of said first recording layer;
• the other of said first and second recording directions being used as the recording direction of said second recording layer;
• each of said recording layers including a data area in which data has a sector structure, and each sector containing at least a layer number for identifying said first recording layer and said second recording layer;
• and
• wherein substantially one half of said amount of data previously recorded on said medium is recorded to a predetermined data area in said data area or said first recording layer, said predetermined data area being smaller than said data area available for recording the data, and the remainder or the data is recorded in said data area of said second recording layer such that a start position of the data in one of said first and second recording layers is substantially at the same radial position as a final position of the data in the other of said first and second recording layers.

A record/playback apparatus comprising:

• means for recording data on a disk-shaped data recording medium on which an amount of data is to be recorded;
• and
• means for reproducing data from said data recording medium, wherein said data recording medium comprising:
• a least a first and a second recording layers;
• a first recording direction from the inner side to the outer side or said medium and a second recording direction from the outer side to the inner side of said medium being determined as directions for recording data;
• one of said first and second recording directions being used as the recording direction of said first recording layer;
• the other of said first and second recording directions being used as the recording direction of said second recording layer;
• each of said recording layers including a data area in which data has a sector structure, and each sector containing at least a layer number for identifying said first recording layer and said second recording layer;
• and
• wherein substantially one half of said amount of data to be recorded on said medium is recorded to a predetermined data area in said data area of said first recording layer, said predetermined data area being smaller than said data area available for recording the data, and the remainder of the data is recorded in said data area of said second recording layer such that a start position of the data in one of said first and second recording layers is substantially at the same radial position as a final position of the data in the other of said first and second recording layers.