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AssigneeSony Corporation
InventorMinoru Tobita
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An optical disc (200) according to the present invention has a recording area divided into 28 zones of from a zone Z0 to a zone Z27. 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.
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.
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.
An apparatus for manufacturing a disc-shaped recording medium comprising:
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.
Dependencies are inferred from the claim text.