Information recording apparatus, information recording method, information reproducing apparatus, and information reproducing method

1. An information recording apparatus for a servo-layerless optical information disk, the information recording apparatus comprising:

a recording position determining unit that determines a recording position format for all or some areas of the servo-layerless optical information disk from a plurality of recording position formats, determines a plurality of recording positions on the servo-layerless optical information disk as specified by the determined recording position format, and determines a plurality of addresses corresponding to the recording positions on the servo-layerless optical information disk as specified by the determined recording position format; and

a recording and reproducing unit that records data at the determined recording positions on the servo-layerless optical information disk as specified by the determined recording position format, and records the determined recording position format at a predetermined position on the servo-layerless optical information disk,

wherein each of the recording position formats respectively specifies a different plurality of recording positions and addresses corresponding thereto.

2. The information recording apparatus according to claim 1 , wherein each of the recording position formats respectively specifies intervals between the different recording positions.

3. The information recording apparatus according to claim 1 , wherein

to reproduce the data at the recording positions, the recording and reproducing unit reproduces the recording position format recorded at the predetermined position on the servo-layerless optical information disk, the recording position determining unit determines the recording positions and the addresses specified by the reproduced recording position format, and the recording and reproducing unit reproduces the data at the recording positions.

4. The information recording apparatus according to claim 3 ,

wherein the determined recording position format further specifies that intervals between the recording positions are constant, and

wherein the determined recording position format recorded at the predetermined position further includes a recording start position of the determined recording positions.

5. The information recording apparatus according to claim 3 ,

wherein the determined recording position format further specifies that intervals between the recording positions are variable, and

wherein the determined recording position format recorded at the predetermined position further includes a recording start position of the determined recording positions from a reference position on the servo-layerless optical information disk.

6. An information recording method for a servo-layerless optical information disk, the information recording method comprising:

determining a recording position format from a plurality of recording position formats for all or some areas of the servo-layerless optical information disk;

determining a plurality of recording positions on the servo-layerless optical information disk as specified by the determined recording position format;

determining a plurality of addresses corresponding to the recording positions on the servo-layerless optical information disk as specified by the determined recording position format; and

recording data at the determined recording positions on the servo-layerless optical information disk as specified by the determined recording position format, and recording the determined recording position format at a predetermined position on the servo-layerless optical information disk.

7. The information recording method according to claim claim 6 , further comprising:

obtaining the recording position format recorded at the predetermined position on the servo-layerless optical information disk; and

recording additional data at the recording positions on the servo-layerless optical information disk as specified by the obtained recording position format.

8. An information reproducing apparatus that reproduces information from a servo-layerless optical information disk, the information reproducing apparatus comprising:

a reproducing unit that reproduces information from the servo-layerless optical information disk; and

a control unit that controls the reproducing unit,

wherein a recording position format is recorded on the servo-layerless optical information disk at a predetermined position,

wherein the control unit controls the reproducing unit to obtain the recording position format, determine a plurality of recording positions on the servo-layerless optical information disk as specified by the obtained recording position format, determine a plurality of addresses for the determined recording positions as specified by the obtained recording position format, and reproduce the information from the servo-layerless optical information disk at the determined recording positions according to the determined addresses, and

wherein the recording position format includes four bits which specify the recording positions, where a first two bits represent a track direction, rotation direction or a multiplexing direction of the recording positions, and a second two bits represent that intervals between the recording positions are constant or variable.

9. An information reproducing method for reproducing information from a servo-layerless optical information disk where a recording position format is recorded on the servo-layerless optical information disk at a predetermined position, the method comprising:

obtaining the recording position format from the predetermined position of the servo-layerless optical information disk;

determining a plurality of recording positions on the servo-layerless optical information disk as specified by the obtained recording position format, and determining a plurality of addresses for the determined recording positions as specified by the obtained recording position format; and

reproducing the information from the servo-layerless optical information disk at the determined recording positions according to the determined addresses,

wherein the recording position format includes four bits which specify the recording positions, where a first two bits represent a track direction, rotation direction or a multiplexing direction of the recording positions, and a second two bits represent that intervals between the recording positions are constant or variable.

10. The information recording apparatus according to claim 1 , wherein the determined recording position format recorded at the first predetermined position consists of four bits where a first two bits represent a track direction, rotation direction or a multiplexing direction of the recording positions, and a second two bits represent that intervals of the recording positions are constant or varying.

11. The information recording apparatus according to claim 10 , wherein the determined recording position format specifies the intervals between the recording positions which are defined by a radial direction and a rotational angle.

12. The information recording method according to claim 6 , wherein the determined recording position format recorded at the first predetermined position consists of four bits where a first two bits represent a track direction, rotation direction or a multiplexing direction of the recording positions, and a second two bits represent that intervals of the recording positions are constant or varying.

13. The information recording method according to claim 12 , wherein the determined recording position format specifies the intervals between the recording positions which are defined by a radial direction and a rotational angle.

14. The information reproducing apparatus according to claim 8 , wherein the determined recording position format specifies the intervals between the recording positions which are defined by a radial direction and a rotational angle.

15. The information reproducing method according to claim 9 , wherein the determined recording position format specifies the intervals between the recording positions which are defined by a radial direction and a rotational angle.