JPH09185826A - Disk-shaped information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk-shaped information recording medium designed to assure a large recording capacity by increasing a recording density. SOLUTION: The tracks TR having servo parts SAVO and data parts DATA of an optical disk of a sample servo system with which recording and reproducing of information are executed by the clock of a single frequency in the fixed state of an angular speed by using pregrooves and tracking control are spirally formed. The servo parts SAVO have address parts ADR where the management information for recording and reproducing of data is recorded and wobble mark parts WBM where tracking information, etc., are given. Both of the groove parts and land parts are used as the recording and reproducing tracks TR. Odd numbered tracks TRodd are formed in the land parts and even numbered tracks TReven , are formed in the groove parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc-shaped information recording medium such as an optical disc for optically recording / reproducing information.

[0002]

2. Description of the Related Art In an optical disc system for recording / reproducing various data by scanning a recording / reproducing track on a recording surface with a laser beam, an optical disc has a constant linear velocity (CLV: Constan
t Linear Velocity), the CLV system that records / plays back and forth data, and the optical disk has a constant angular velocity (CAV: C
CAV method for recording / reproducing data by rotationally driving the onstant angular velocity), and MCAV (Modified CAV) method for increasing the recording efficiency by making the spatial recording density almost constant on the inner and outer circumferences of the disc. Are known.

Conventionally, in an optical disc, either a land portion or a groove portion formed concentrically or spirally on a recording surface is used as a recording / reproducing track.
Generally, as shown in FIG. 6, a land portion formed in a spiral shape is used as a recording / reproducing track TR.

Further, a continuous servo system for performing tracking control or the like by using pregrooves continuously provided along the track, or tracking control or the like by utilizing a servo section discretely provided on the track is used. A known sample servo method is known. In the continuous servo system, tracking is performed on the land portion by using the optical phase difference between the land portion and the groove portion,
Information is recorded and reproduced on the land portion, that is, the recording and reproducing track.

On the recording / reproducing track, there is provided an address section in which management information for recording / reproducing data is recorded.

FIG. 7 shows the configuration of the servo section of the sample servo type optical disk.

The servo section SAVO shown in FIG. 7 has an address section ADR formatted with a gray code according to a pit position and a wobble mark section for giving tracking information and the like. Tracking is performed by the wobble pits of the wobble mark portion WBM to record / reproduce data in the land portion. That is, the land portion is used as a recording / reproducing track. The address portion where the management information for recording / reproducing data is recorded is arranged on the recording / reproducing track, that is, the land portion. In the data section, grooves are provided on both walls to reduce the influence of crosstalk from adjacent tracks.

Further, as the optical disk, a recordable RAM disk such as a so-called ROM disk dedicated to reproduction, a write-once disk, a magneto-optical (MO) disk, a ROM area and an R area.
A so-called hybrid disc having an AM area is known.

[0009]

By the way, if the track pitch is narrowed to increase the density in the radial direction in order to cope with the increase in the capacity of the disk, crosstalk between tracks becomes a problem, especially due to preformatting. The embossed pits have a large influence on the adjacent tracks, and the influence from the address portion recorded as the embossed pits by the preformat to the data portion or the address portion of the adjacent track becomes a problem.

Further, as a method for coping with the increase in capacity of the disc, it is possible to optimize the physical conditions of the land portion and the groove portion on the recording surface and use the land portion and the groove portion as recording / reproducing tracks respectively. Conceivable.

Therefore, in view of the conventional situation as described above, an object of the present invention is to provide a disc-shaped information recording medium capable of increasing the recording density and ensuring a large recording capacity.

Another object of the present invention is to provide a disc-shaped information recording medium in which the land portion and the groove portion are used as tracks to ensure the continuity of the tracks.

[0013]

DISCLOSURE OF THE INVENTION The present invention is a disk-shaped information recording medium in which information is recorded and reproduced by a clock of a single frequency in a state where the angular velocity is constant, and tracks are formed in a land portion and a groove portion. The address portion is arranged in each track in the radial direction.

The disc-shaped information recording medium according to the present invention is characterized in that the land portion and the groove portion are switched on the track an odd number of times in one round.

A disc-shaped information recording medium according to the present invention is characterized in that the address portion is arranged at a switching position between a land portion and a groove portion on a track.

The disc-shaped information recording medium according to the present invention is characterized in that the address portion is formatted with a gray code by a pit position.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

The disc-shaped information recording medium according to the present invention is constructed, for example, as shown in FIG. The disc-shaped information recording medium shown in FIG. 1 is a sample servo type optical disc in which information is recorded / reproduced by a clock having a single frequency in a state where tracking control is performed using a pre-groove and an angular velocity is constant. Part SAVO and data part DAT
A track TR having A and A is formed in a spiral shape.
The servo section SAVO has an address section ADR in which management information for recording / reproducing data is recorded, and a wobble mark section WBM for giving tracking information and the like.

In this disc-shaped information recording medium, both the groove portion and the land portion are used as the recording / reproducing track TR, the odd number track TR _odd is formed in the land portion, and the even number track TR _even is in the groove portion. Has been formed. In this disc-shaped information recording medium, both the groove portion and the land portion are used as the recording / reproducing track TR to realize an optical disc having a high recording capacity and a large recording capacity.

In this disc-shaped information recording medium, the address portions ADR are arranged in the radial direction on both the _odd- numbered tracks TR _odd and the even-numbered tracks TR _even . Track number information having a value depending on the pit position is recorded in the address portion ADR. Here, the address part ADR is formatted with a gray code depending on the pit position so that the pit positions are different by one in adjacent tracks.

Although there is an influence of the pit signal of the adjacent track, its amplitude is smaller than the on-track signal amplitude. Therefore, the magnitude of the amplitude is checked at each timing, and the value corresponding to the pit position having the largest amplitude is used as the reproduction data. Just do it.
As a result, it is possible to reduce the influence of the address portions ADR between the adjacent tracks.

FIG. 2 shows an example of the waveform of the reproduced signal on the track having the lower track number "1". At timing t0, there is crosstalk from the pit indicating the address information on the adjacent track TR0, but the amplitude is not large because it is not on-track. At timing t1, a sufficiently large amplitude is obtained because the reproduction signal of the on-track pit is output. At timing t2, there is crosstalk from the pit indicating the address information on the adjacent track TR2, but the amplitude is not large because it is not on-track. At timing t3, the signal from the track TR3 has almost no effect.

Therefore, since the reproduction signal amplitude at the timing t1 is the maximum, the value = 1 corresponding to this pit position is used as the suspicious information of the track number.

In some cases, the pit size may be optimized so that the difference can be easily detected. Further, since the rotation synchronization information (segment or sector number) in the address information is the same in the radial direction, the problem of crosstalk does not occur.

The track number information is entirely gray-coded according to the pit position.

As described above, even if the address portions are aligned in the radial direction and the pits are present in the adjacent tracks, if they are formed by the gray code according to the pit positions,
Even if there is crosstalk, the address information can be reproduced by the difference detection method or the like.

Further, in the disc-shaped information recording medium in which both the groove portion and the land portion are used as the recording / reproducing track TR to increase the recording density, the pickup traces the track TR0 of the land portion as shown in FIG. After one lap, track TR2 is entered, and after one more lap, track T is entered.
You will enter R4. When the pickup traces the track TR1 in the groove portion and makes one round, it enters the track TR3, and when it makes another round, it enters the track TR5. Therefore, it is impossible to trace the land portion and the groove portion alternately, that is, to continuously trace the track without jumping.

Therefore, for example, as shown in FIG. 4, the groove portion and the land portion are exchanged once per one turn, and cutting is performed. Thereby, the continuity of the track can be secured. Further, the address portion ADR is provided at the portion where the land portion changes to the groove portion and the groove portion changes to the land portion.

Further, it is not necessary to replace the groove portion and the land portion once per revolution. For example, as shown in FIG. 5, an example of three revolutions per revolution is performed once per revolution. If so, the continuity of the truck can be secured.

The present invention is not limited to the disk-shaped information recording medium of the sample servo system as described above, but can be applied to the disk-shaped information recording medium of the continuous servo system. For example, a preamble (VFO) for clock extraction (PLL pull-in) and an address mark for synchronous pull-in (AM) may be provided in front of the address portion formed by the gray code by the pit position. Since the preamble and the address mark are the same in the radial direction, crosstalk is not a problem.

[0031]

Since the disc-shaped information recording medium according to the present invention has tracks formed in the land portion and the groove portion and the address portions are arranged in the radial direction in each track, the disc-shaped information recording medium is formed in a single state with a constant angular velocity. Even with a disc-shaped information recording medium in which information is recorded and reproduced by a clock of one frequency, it is possible to increase the recording density and secure a large recording capacity.

Further, in the disc-shaped information recording medium according to the present invention, the track continuity can be ensured by switching the land portion and the groove portion on the track an odd number of times in one round.

Further, in the disc-shaped information recording medium according to the present invention, since the address part is formatted by the gray code by the pit position, there is little possibility that the address part is erroneously detected by crosstalk.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an essential configuration of a disc-shaped information recording medium according to the present invention.

FIG. 2 is a waveform diagram showing a waveform example of a reproduction signal on a track of a lower track number “1” of the disc-shaped information recording medium.

FIG. 3 is a diagram for explaining a state of a trace accompanied by a track jump of a track on the disc-shaped information recording medium.

FIG. 4 is a diagram showing a portion where the groove portion and the land portion of the disc-shaped information recording medium, which are used as continuous recording and reproducing tracks by exchanging the groove portion and the land portion once, are exchanged.

FIG. 5 is a diagram showing a disc-shaped information recording medium in which a groove portion and a land portion are replaced three times in a circle and used as continuous recording / reproducing tracks.

FIG. 6 is a diagram showing recording / reproducing tracks on a general optical disc.

FIG. 7 is a plan view schematically showing a configuration of a servo section of a sample servo type optical disc.

[Explanation of symbols]

 DATA data part SAVO servo part ADR address part WBM wobble mark part

Claims (6)

[Claims] 1. A disc-shaped information recording medium in which information is recorded and reproduced by a clock having a single frequency with a constant angular velocity, wherein tracks are formed in a land portion and a groove portion, and an address portion is formed in each track. A disc-shaped information recording medium, which is arranged in a radial direction. 2. A land portion and a groove portion are 1 on a track.
The disk-shaped information recording medium according to claim 1, wherein the disk is switched an odd number of times around the circumference. 3. The disc-shaped information recording medium according to claim 2, wherein the address portion is arranged at a switching position between a land portion and a groove portion on a track. 4. The disc-shaped information recording medium according to claim 1, wherein the address portion is formatted with a gray code by a pit position. 5. The disc-shaped information recording medium according to claim 2, wherein the address portion is formatted with a gray code by a pit position. 6. The disc-shaped information recording medium according to claim 3, wherein the address portion is formatted with a gray code by a pit position.