Disc-shaped recording medium, manufacturing method and manufacturing device thereof, and data recording method
View Patent ↗An optical disc ( 200 ) according to the present invention has a recording area divided into 28 zones of from a zone Z 0 to a zone Z 27 . In a given zone, the number of waves of a wobble is set so as to be equal, that is, the number of waves of the ADIP carrier is set so as to be equal, between optional two neighboring turns of the track or between optional two neighboring tracks. This achieves inphase-outphase matching on an average, for decreasing a WPP signal, so that such an optical disc may be provided in which no low frequency components are superposed on push-pull signals, even though the optical disc is of such a type in which the track pitch is narrower than 1.6 μm, such as 1.25 μm, or in which a mark is detected by DWDD from a groove, as in the case of the next generation MD2.
1. A disc-shaped recording medium wherein a signal recording surface of the disc-shaped recording medium is split into a plurality of zones and wherein a track(s) is formed spirally or concentrically, such that, in each zone, the number of waves of a wobble is the same from one turn of the track to the next or from one track to the next, wherein the rate of change of the distance from the center of the disc-shaped recording medium to an outermost rim of each zone is 3% or less between neighboring zones.
2. The disc-shaped recording medium according to claim 1 wherein, in each zone, the wobble of a given turn of the track is in phase with the wobble of a neighboring turn of the track or a given track is in phase with the wobble of a neighboring track.
3. The disc-shaped recording medium according to claim 1 wherein at least two turns of a dummy track or at least two dummy tracks incapable of recording and/or reproduction are provided in the neighborhood of a boundary between two given neighboring zones.
4. The disc-shaped recording medium according to claim 1 wherein data are recorded in terms of an optional block as a unit and wherein two block units in the vicinity of the innermost rim of each zone and two block units in the vicinity of the outermost rim of each zone are formed as dummy tracks incapable of recording and/or reproduction.
5. A method for manufacturing a disc-shaped recording medium wherein the speed of rotation of the disc-shaped recording medium, having a signal recording surface split into a plurality of zones along the radial direction, is changed from one zone to the next, and wherein the wobble frequency is controlled so that, in each zone, the number of waves of the wobble of neighboring turns of the track is the same from one turn of the track to the next or the number of waves of the wobble of neighboring tracks is the same from one track to the next, wherein the wobble frequency is controlled so as to satisfy the condition that a quotient obtained on dividing the value of the clocks output by a phase synchronization circuit, that can be multiplied by M/N, with the number of waves per turn of the track or per track, is of the same value from one zone to the next, and the condition that a quotient obtained on dividing the product of the number of waves of the wobble per turn of the track or per track and the number of turns of the tracks or the number of tracks in a given zone by the number of waves of the wobble per one recording unit, representing a unit of data recording, is an integer.
6. An apparatus for manufacturing a disc-shaped recording medium comprising:
disc rotating means for rotationally driving a disc-shaped recording medium having a signal recording surface divided into a plurality of zones along the radial direction;
driving means for driving said disc rotating means;
a phase synchronization circuit for generating optional clocks; and
controlling means for controlling said driving means so that the speed of rotation of said disc-shaped recording medium is changed from one zone of the disc-shaped recording medium to the next and for controlling said phase synchronization circuit so that, in each zone, the number of waves of the wobble of optional two neighboring turns of the track or optional two tracks is equal from one zone of the disc-shaped recording medium to the next.
7. The apparatus for manufacturing a disc-shaped recording medium according to claim 6 wherein said controlling means controls said phase synchronization circuit so as to satisfy the condition that a quotient obtained on dividing the value of the clocks which are output by a phase synchronization circuit, and which can be multiplied by M/N, with the number of waves of the wobble per turn of the track or per track, is of the same value from one zone to the next, and the condition that a quotient obtained on dividing the product of the number of waves of the wobble per turn of the track or per track and the number of turns of the tracks or the number of tracks in a given zone by the number of waves of the wobble per one recording unit, representing a unit of data recording, is an integer.
8. A data recording method in which, in recording data on a disc-shaped recording medium, having a signal recording surface divided into a plurality of zones along a radial direction, said recording medium including a track(s) formed spirally or concentrically so that, in each zone, the number of waves of a wobble is equal from one turn of the track to the next or from one track to the next, recording of said data is inhibited in the vicinity of a boundary between neighboring zones, wherein, in recording the data on said disc-shaped recording medium, recording is prohibited for at least two turns of the track or at least two tracks in the vicinity of a boundary between neighboring zones.
9. The data recording method according to claim 8 wherein, in recording the data on said disc-shaped recording medium, recording is prohibited for two block units in the vicinity of the innermost rim of each zone and for two block units in the vicinity of the outermost rim of each zone.