Information recording medium, and recording method and reproducing method thereof
View Patent ↗An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.
1. An information recording medium having an information track formed spirally or in coaxial circles comprising:
a recordable area for information having a groove in a first depth being prerecorded with a frequency signal and a land pre-pit address signal from an inner circumference of said information track;
a first read only area having a pit in a second depth prerecorded with a frequency signal to be recorded with a reproduction signal as a pit; and
a second read only area having a pit in a first depth prerecorded with a frequency signal and a land pre-pit address signal to be recorded with a reproduction signal as a pit,
wherein a tracking error signal at a time of tracking off in a boundary between said recordable area and said first read only area is defined as a ratio of maximum amplitude in both directions from a center of maximum amplitude of said tracking error signal at the time of tracking off in said recordable area.
2. A reproducing method of information recording medium having an information track formed spirally or in coaxial circles comprising:
a recordable area for information having a groove in a first depth being prerecorded with a frequency signal and a land pre-pit address signal from an inner circumference of said information track;
a first read only area having a pit in a second depth prerecorded with a frequency signal to be recorded with a reproduction signal as a pit; and
a second read only area having a pit in a first depth prerecorded with a frequency signal and a land pre-pit address signal to be recorded with a reproduction signal as a pit,
wherein a tracking error signal at a time of tracking off in a boundary between said recordable area and said first read only area is defined as a ratio of maximum amplitude in both directions from a center of maximum amplitude of said tracking error signal at the time of tracking off in said recordable area,
said reproducing method comprising the steps of:
reproducing a land pre-pit address signal of said information track; and
tracking said boundary continuously on the basis of amplitude of a tracking error signal in said recordable area and said first read only area in accordance with reproduced said land pre-pit address signal.