JP2000339691A - Optical disk recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize various applications by combining two regions created by making one part of a data area section a ROM region consisting of pre- mastered pits and a recordable groove region in a recording medium in which the ratio of a track pitch to the diameter of a beam spot is a specified value or less. SOLUTION: A wobbled groove exists in a region outside the data region of an optical disk, which constitutes a recordable region. Also, the inside is ROM regions consisting of pre-mastered pits, where software or data are recorded. In an optical disk in which the ratio TPp/Bd of a track pitch(Tp) in which a push-pull signal is made rapidly smaller to a beam spot diameter(Bd) defined by 1/e2 is 1.1 or less, the track pitch (TPp) of the pit part is set larger than the track pitch (TPg) of a groove part. Then, TPp can be set to the prescribed value by making the depth of a pit greater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an optical disk recording medium.

[0002]

2. Description of the Related Art Among optical discs, compact discs (CDs) are widely used for audio reproduction. This audio CD is for reproduction only and has a drawback that information cannot be recorded and edited.
The development of a writable CD has been desired. Similarly, there has been a demand for a CD-ROM capable of writing files such as general documents, data, and still images.

In response to such a demand, a CD having a writable recording layer has been proposed. That is,
A donut-shaped surface on the inner peripheral side of a disc-shaped substrate having a circular hole at the center has a pre-pit portion on which lead-in information defined in the Compact Disc Standard is recorded, and a substrate surface on the outer peripheral side of the pre-pit portion Is provided with a tracking guide groove or wobble pit for tracking,
Further, it is a DRAW type information recording medium having a writable recording layer provided on its surface (Japanese Patent No. 2597).
No. 491).

[0004]

SUMMARY OF THE INVENTION The present invention relates to an optical disk recording medium having a ROM area and a writable recording area, which has a large DVD medium capacity and can be used for various applications by combining the ROM area and the recording area in the data area. It is an object of the present invention to provide an optical disk recording medium that can be used.

Another object of the present invention is to obtain a particularly large wobble signal in such an optical disk recording medium, thereby enabling good control of disk rotation and address reproduction during additional recording. An object of the present invention is to provide an optical disk recording medium.

Still another object of the present invention is to provide a DVD-R having a ROM area in a part of a data area.
It is an object of the present invention to provide an optical disk recording medium capable of favorably performing disk rotation control and address reproduction at the time of additional writing on a W or DVD + RW medium.

[0007]

According to the present invention, there is provided (1) an optical disk recording medium in which a ratio Tp / Bd of a track pitch (Tp) to a beam spot diameter Bd defined by 1 / e ² is 1.1 or less. 2. The optical disk recording medium according to claim 1, wherein a part of the data area part comprises a ROM area composed of pre-mastered pits and a recordable groove area. (2) The track pitch of the ROM area is equal to the track pitch of the groove area. (3) The track pitch of the groove area is 0.74 ± average on the entire surface of the disk.
0.01 μm, track pitch in ROM area is 0.79 ± 0.01 μm to 1.00 ± 0.0
The optical disk recording medium according to the above (2), which is 1 μm.

FIG. 1 is a schematic diagram of the present invention. The area outside the data area of the optical disk has a wobbled groove and is a recordable area. In addition, the inside consists of a ROM area consisting of pre-mastered pits,
Software and data are recorded. Generally, the push-pull signal of the pit part is
If the depth and width are the same, it will be reduced to about half. Also, as shown in FIG. 2, when the track pitch becomes smaller relative to the reproduction beam spot, the push-pull signal rapidly decreases. Since the wobble signal is proportional to the size of the push-pull signal, the smaller the push-pull signal, the smaller the wobble signal. In the present invention, in FIG. 2, TPp / Bd at which the push-pull signal sharply decreases
In the optical disk having the configuration of FIG.
The track pitch TPp of the pit portion is set to be larger than the track pitch TPg of the groove portion. A specific setting value is 4.7 GB when only the groove area is used.
In the case of an optical disk having a data capacity of 容量, in order to minimize the capacity, TPg is 0.74 ±
0.01 μm, TPp is 0.79 ± 0.01 μm-1.
00 ± 0.01 μm is appropriate. 635n for recording wavelength
In a DVD-R medium using m, the relationship between the push-pull signal and the track pitch width is as shown in FIG.
Although about μm is required, TPp can be set to the above value by making the pit depth deeper.

[0009]

EXAMPLE On a polycarbonate substrate having an outer diameter of 120φ and a thickness of 0.6 mm, pits having a radius of 24 mm to 30 mm and a track pitch of 0.80 μm were 8/16 modulated and the ROM area was changed from 30 mm to 58 mm and a track pitch of 0.74 μm
m groove areas were provided. At this time, the wobble amplitude of the pits and grooves was 12 nm. On this, a cyanine dye is applied by a spinner as a light absorption layer, and after drying, aluminum is provided as a reflection layer by a sputtering method, and a protective layer made of an ultraviolet curable resin is further provided thereon. Were bonded face to face to form a DVD-R disc having a ROM area. When this disc was reproduced by a recording / reproducing apparatus having a pickup with a wavelength of 635 nm, a PP (radial p.
ush-pull amplitude before
recording: 0.31, wobble CNR: 37 dB, pit part PPa (radial push)
-Pull amplitude after rec
ordering) is 0.39, wobble CNR is 33dB
Was a good value.

[0010]

COMPARATIVE EXAMPLE A DVD-R disc having a ROM area was produced by the same construction and production method as in the example. However, only the track pitch of the ROM section is 0.74 μm as in the case of the groove section.
And When this optical disc was reproduced by the same recording / reproducing apparatus as in the example, the PPa of the pit portion was 0.32, the wobble CNR was 28 dB, and the wobble CNR value was insufficient.

[0011]

According to the optical disk recording medium of the present invention, since the data area is composed of a ROM area composed of pre-mastered pits and a recordable groove area, various applications can be combined with the recordable area. It is possible to have it on a recording medium. In particular, DVD media having a TPp / Bd of 1.1 or less have large capacities, so that application development is widespread. In the optical disk recording medium according to the second aspect, the track pitch (TPp) of the ROM area is larger than the track pitch (TPg) of the groove area. Sometimes, disk rotation control and address reproduction can be performed well. In the optical disk recording medium according to the third aspect, TPg is 0.74 ± 0.01 on the average of the entire disk, while TPp is 0.79 ± 0.01 on the average of the entire disk.
DVD-R, DVD-R having a ROM area in a part of the data area.
In the case of / W, DVD + RW media, disc rotation control and address reproduction can be favorably performed during additional recording.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an optical disk recording medium of the present invention.

FIG. 2 is a graph showing the relationship between Tp / Bd and push-pull (PP).

FIG. 3 shows a track pitch (TP) and a push-pull (P)
The graph which shows the relationship of P).

Claims (3)

[Claims] 1. A ratio Tp / Bd of a track pitch (Tp) to a beam spot diameter Bd defined by 1 / e ² is 1.
In an optical disk recording medium having a size of 1 or less, a part of a data area portion is composed of pre-mastered pits.
The optical disc recording medium according to claim 1, comprising an OM area and a recordable groove area. 2. The optical disk recording medium according to claim 1, wherein a track pitch of the ROM area is larger than a track pitch of the groove area. 3. The track pitch of the groove area is 0.74 ± 0.01 μm on average over the entire disk, and the track pitch of the ROM area is 0.79 ± 0.01 on average over the entire disk.
3. The optical disk recording medium according to claim 2, wherein the diameter is in a range of from μm to 1.00 ± 0.01 μm.