JPH0729240A - Optical recording medium and recording and reproducing method using the same - Google Patents

Abstract

PURPOSE:To provide an optical recording medium easy to produce and capable of high density recording and reproduction of information with high reliability as an optical recording medium with an RAM region in which information can be recorded and reproduced and an ROM region in which information is previously formed as geometric ruggedness and only reproduction is carried out and to provide recording and reproducing methods using the optical recording medium. CONSTITUTION:An RAM region is composed of a magneto-optical RAM region 10 and a phase change RAM region 11, an ROM region 12 is disposed between the regions 10, 11 and a reflecting layer common to the regions 10-12 is formed in the regions 10-12 without forming a recording film in the region 12. In relation to recording and reproduction in the RAM region, control information and retrieval information which are frequently rewritten are handled in the magneto-optical RAM region 10 and information which is not frequently rewritten is handled in the phase change RAM region 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium for recording / reproducing information with a laser beam and a recording / reproducing method thereof, and more particularly to an optical recording having a recordable / reproducible RAM area and a reproducible ROM area. The present invention relates to a medium and a recording / reproducing method thereof.

[0002]

2. Description of the Related Art An optical disk or the like for recording or reproducing information by laser light has a high recording density and thus has an excellent feature as a large capacity storage system.

ISO (International O)
rganization for Standarddiz
ation) -compliant optical disk as a 130 mm magneto-optical recording medium, a user-recordable area (RA
In a radius of 29.5 to 29.7 mm inside the M area), there is a read-only area (ROM area) called SFP in which the recording and reproducing conditions for recording and reproducing in the user area are formed by geometrical unevenness. The same applies to the 90 mm magneto-optical recording medium. There is also a read-only optical recording medium (CD, CD-ROM, LD, etc.) in which information is recorded on the entire optical disc only by geometrical irregularities. Furthermore,
There is also an optical recording medium (partial ROM medium) in which an application program or the like is formed in the ROM area (for example, JP-A-1-144252 and JP-A-4-13).
No. 4738).

[0004]

6 and 7 are partial cross-sectional views of a conventional partial ROM medium including a conventional magneto-optical RAM area 31 and a ROM area 32, respectively, and a block diagram showing a conventional recording / reproducing apparatus. It is a figure. RO in Figure 6
In the M medium, only a groove for tracking control called a pre-groove 33 exists in the RAM area 31, whereas in the ROM area 32 where information is formed in advance by geometrical unevenness, other than the pre-groove 33. There is a pre-pit 34. The pre-groove 33 and the pre-pit 34 are formed on the substrate 35, and the recording film 36 is formed over the entire surface of the substrate 35.

In this ROM medium recording / reproducing apparatus, as shown in FIG. 7, an optical recording medium 42 is rotated at a constant rotation speed by a driving motor 41, and a laser beam is emitted from a laser beam irradiating device 43. The laser beam irradiating device 43 is further irradiated with the laser beam irradiating device 42 in the radial direction of the optical recording medium 42 by the feeding device 44 so that the laser beam swirls the optical recording medium. More specifically, the laser light emitted from the laser light source 45 is focused by the focusing optical component 46, the beam splitter 47, 1 /
The surface of the optical recording medium on which the recording film is formed is focused and irradiated through the 4λ plate 48, the mirror 49, the objective lens 50 and the like. When the laser light scans the recording marks or pre-pits of the optical recording medium, the reflected light from the laser light is reflected by the objective lens 50,
The light reaches the photodetector 51 via the mirror 49, the quarter-wave plate 48, the beam splitter 47, etc., and is converted into an electric signal and demodulated. By performing the focusing servo and the tracking servo in the laser light irradiation described above, it is possible to maintain the predetermined focused state and irradiate the aimed track position. In the magneto-optical RAM area 31, binarized signals of "1" and "0" can be taken out depending on whether the magnetization is upward or downward in the direction perpendicular to the film surface of the recording film. In the ROM area 32, binary signals of "1" and "0" can be taken out depending on the presence or absence of the prepit 34.

In such a conventional partial ROM medium, since the recording film is formed on the entire surface of the medium substrate, when the read laser beam is incident on the ROM area, it is absorbed by the recording film and the information is reproduced for the read-only optical recording medium. There is a problem that the device malfunctions, and the magneto-optical recording film is used as a RAM.
Since it is used as an area, there is a problem that information cannot be recorded at a high density, so it cannot be said to be sufficiently practical.

An object of the present invention is to provide an optical recording medium which has high reproduction accuracy and can record information at high density, and a recording / reproducing method thereof.

[0008]

In the optical recording medium of the present invention, there are provided a RAM area for recording / reproducing information and a ROM area for preliminarily forming information and forming only pits having geometrical irregularities. An optical recording medium also provided,
The RAM area is composed of a magneto-optical RAM area and a phase change RAM area, and the ROM area is a magneto-optical RAM area and a phase change R.
A magneto-optical RA is provided between the AM area and the ROM area.
The magneto-optical RAM area and the phase-change RAM are configured so that there is no recording film in the M area and the phase-change RAM area.
The area and the reflective layer in the ROM area are configured to be common.

Next, in the recording / reproducing method of the optical recording medium of the present invention, the magneto-optical RAM area having the common reflective layer and capable of recording / reproducing information, the phase change RAM area capable of recording / reproducing information and the information are geometrically arranged in advance. An optical recording medium which is formed as a concavo-convex pit row and is also provided with a ROM area capable of only reproduction is used. User record information is recorded in the phase change RAM area and geometric information is recorded in the magneto-optical RAM area. It is possible to record the management information or the search information of the user record information in a form that is not a geometrical unevenness, and to read the user record information from the phase change RAM area and the management information or the search information from the magneto-optical RAM area during reproduction. Characterize.

[0010]

Thus, the RAM area is divided into the magneto-optical RAM area and the phase change RAM area, and the magneto-optical RAM is provided in the ROM area.
The recording film in the area and the recording film in the phase change RAM area are not provided, and the magneto-optical RAM area, the phase change RAM area, and the ROM area are made to have a common reflection layer, thereby preventing a malfunction during information reproduction. Further, the user record information is recorded in the phase change RAM area, and the management information or the search information is recorded in the magneto-optical RAM
By recording in the area, the user information can be recorded at high density. In addition, the ROM area has a magneto
By arranging between the M area and the phase change RAM area,
The optical recording medium can be easily manufactured.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a plan view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line A--N of FIG.

In the optical recording medium 20 shown in FIG. 1, the recording and reproducing portion formed on the ring uses the magneto-optical RAM area 10 utilizing the magnetic effect and the difference in reflectance between crystalline and amorphous. The phase change RAM area 11 and the ROM area 12 are divided into three areas, and the ROM area 12 is the magneto-optical RAM area 1.
It is arranged between 0 and the phase change RAM area 11.

As the substrate 15, a transparent member such as a polycarbonate resin plate, a polyolefin resin plate, an acrylic resin plate, an acrylic resin plate with a photopolymer, or a glass plate with a photopolymer is used. Magneto-optical RAM area 1
0 and the phase change RAM area 11 are formed with a pre-groove 13 formed of a V-shaped groove on a ring for tracking control,
In the area 12, a pre-pit 14 is formed in addition to the pre-groove 13. Data such as an application program is represented by the pattern of the pre-pits 14. The pregrooves 13 and the prepits 14 are formed on a polycarbonate resin plate, a polyolefin resin plate, an acrylic resin plate, a glass plate itself, or a photopolymer. An antireflection layer, a surface hardening layer, or the like may be provided on the substrate 15 on the side opposite to the side where the pregrooves 13 and the prepits 14 are formed.

A magneto-optical recording film 16 is provided on the substrate 15 in the magneto-optical RAM area 10, and a phase change recording film 116 is provided on the substrate 15 in the phase change RAM area 11. There is no recording film on the substrate 15 in the ROM area 12. A reflective layer 17 is commonly formed on the magneto-optical RAM area 10, the phase change RAM area 11, and the ROM area 12 formed in this way.

The magneto-optical recording film 16 comprises a first dielectric layer 161,
The magneto-optical layer 162 and the second dielectric layer 163 are sequentially formed. The first dielectric layer 161 and the second dielectric layer 1
As a material of 63, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride,
It is particularly desirable to use hydrogenated silicon carbide or tantalum oxide as a main component.

The material of the magneto-optical layer 162 is TbFe.
, TbFeCo, TbFeTi, TbFeCoT
i, TbFeCr, TbFeCoCr, TbFe
Ta, TbFeCoTa, TbFeNiCr, T
bFeCoNiCr, TbGdFe, TbGdFe
Co, TbGdFeTi, TbGdFeCoTi
, TbGdFeCr, TbGdFeCoCr, T
bGdFeTa, TbGdFeCoTa, TbGd
FeNiCr, TbGdFeCoNiCr, TbD
yFe, TbDyFeCo, TbDyFeTi,
TbDyFeCoTi, TbDyFeCr, TbD
yFeCoCr, TbDyFeTa, TbDyFe
CoTa, TbDyFeNiCr, TbDyFeC
oNiCr, TbGdNdFe, TbGdNdFe
Co, TbGdNdFeTi, TbGdNdFeC
oTi, TbGdNdFeCr, TbGdNdFe
CoCr, TbGdNdFeTa, TbGdNdF
eCoTa, TbGdNdFeNiCr, TbGd
NdFeCoNiCr, TbGdDyFe, TbG
dDyFeCo, TbGdDyFeTi, TbGd
DyFeCoTi, TbGdDyFeCr, TbG
dDyFeCoCr, TbGdDyFeTa, Tb
GdDyFeCoTa and TbGdDyFeNiCr
Alternatively, TbGdDyFeCoNiCr is particularly desirable. Further, a plurality of other layers may be stacked on these layers. Also,
GdFe, GdFeCo, GdFeTi, GdF
eCoTi, GdFeCr, GdFeCoCr,
GdFeTa, GdFeCoTa, GdFeNiC
r, GdFeCoNiCr, GdNdFe, Gd
NdFeCo, GdNdFeTi, GdNdFeC
oTi, GdNdFeCr, GdNdFeCoCr
, GdNdFeTa, GdNdFeCoTa, G
A read layer such as dNdFeNiCr or GdNdFeCoNiCr may be stacked.

The phase change recording film 116 is the first dielectric layer 116.
1, a phase change layer 1162, and a second dielectric layer 1163 are sequentially formed. The material of the first dielectric layer 1161 and the second dielectric layer 1163 is a mixture of zinc sulfide and silicon dioxide, silicon nitride, silicon oxynitride, aluminum nitride, aluminum oxynitride, or hydrogenated silicon carbide. It is especially desirable to use tantalum oxide as the main component. As a material of the phase change layer 1162, a compound of a chalcogen element is desired, but GeS is particularly preferable.
bTe is preferred. A small amount of element such as nitrogen may be added to the phase change layer 1162.

An aluminum alloy is desirable as the material of the reflective layer 17. As additive elements, Ti, Cr,
Ta, Ni and NiCr are particularly desirable. On the reflective layer 17, a UV curable resin, a dense dielectric having a film quality, or a protective layer 18 such as a metal having a low thermal conductivity may be provided.

Referring again to FIG. 1, 21 is the outer edge of the disk,
Reference numeral 22 denotes a disk center hole, which is used for the magneto-optical RAM area 10,
The phase change RAM area 11 and the ROM area 12 are formed between the outer peripheral side undeposited area 23 and the inner peripheral side undeposited area 24.

As a method of forming a film on a disk substrate, for example, an inner film forming mask that covers the inner peripheral side unformed film area 24 and R
A magneto-optical recording film 16 is formed on the magneto-optical RAM area 10 by mounting an outer film-forming mask covering the OM area 12 on the substrate, and an inner-film forming mask covering the ROM area 12 on the inner side. The phase-change recording film 116 is formed in the phase-change RAM area 11 by mounting a non-film-formation mask covering the area 23 on the substrate, and finally, an intra-film-formation mask covering the area 24 and a film formation covering the area 23. After mounting the outer mask on the substrate, the reflective layer 17 is formed commonly in the regions 10, 12, and 11.

In this embodiment, since the ROM area 12 does not have a recording film and the film does not absorb light, the reproduction accuracy is improved. Further, since the high-density recording is possible in the phase change RAM area 11, the recording / reproducing density of the disk as the partial ROM is improved.

Next, a recording / reproducing apparatus suitable for such an optical recording medium will be described with reference to FIG.

In the recording / reproducing apparatus of FIG. 3, the driving motor 61 rotates the optical recording medium 20 of FIGS. 1 and 2 at a constant rotation speed, and at the same time, the laser beam is emitted from the laser beam irradiation device 63. The laser light irradiation device 63 is moved in the radial direction of the optical recording medium 20 by the feeding device 64 so that the laser light scans the optical recording medium in a spiral shape. More specifically, the laser light emitted from the laser light source 65 is focused by the focusing optical component 66, the beam splitter 67, and the 1/4 λ plate 6.
8, the mirror 69, the objective lens 62 and the like are focused and irradiated onto the surface of the optical recording medium on which the recording film is formed. When the laser light scans the recording / reproducing area of the optical recording medium, the reflected light from the laser light scans the objective lens 62, the mirror 69, 1 /
It reaches the photodetector 61 via the 4λ plate 68, the beam splitter 67, etc., is converted into an electric signal, and is demodulated by the demodulation circuit 70. By performing the focusing servo and the tracking servo in the laser light irradiation described above, it is possible to maintain the predetermined focused state and irradiate the aimed track position.

The recording / reproducing apparatus further includes a user information output section 71, a search management information output section 72 for outputting search information and management information relating to the user information, and a laser light irradiation apparatus 65 for outputting information from the respective output sections 71, 72. And a control circuit 74 for controlling each part.

In the present embodiment, the laser light irradiation device 65 is
Magneto-optical RAM area 10 of optical recording medium 20 and phase change RAM
It is used as a recording light source for the area 11 and as a reproducing read light source for all areas. Detector 61 and demodulation circuit 7
Although 0 has separate detectors for the magneto-optical RAM area 10 and the optical phase change area 11, the control circuit 74 determines which detector the demodulation circuit 70 demodulates. Although not shown in FIG. 3, it goes without saying that when information is recorded in the magneto-optical RAM area 10 of the optical recording medium 20, there is a means for applying a magnetic field in the direction perpendicular to the substrate surface.

Next, a recording / reproducing method suitable for such an optical recording medium will be described with reference to FIGS.

The user information recording method is, as shown in FIG. 4, a "moving step to the phase change RAM area" in which the laser light irradiation apparatus 63 is moved by the feeding device 64 so that the phase change RAM area 11 can be irradiated. 31, a “user information recording step” 32 for recording the user information output from the user information output unit 71 on the optical recording medium 20, and a laser light irradiation device 63 by the sending device 64 for the magneto-optical RAM area 10.
“Movement step to the magneto-optical RAM area” 33 for irradiating the laser beam, and recording the management information and the search information on the user information record output from the search / management information output unit 72 on the optical recording medium 20. Management information recording process "34
And consists of at least.

As shown in FIG. 5, the reproducing method of the user information includes a "moving step to the magneto-optical RAM area" 41 for moving the laser beam irradiation device 63 so that the magneto-optical RAM area 10 can be irradiated, and management. "Management information reproducing step" 42 for reproducing information from the optical recording medium 20, and the laser light irradiation device 6
From the "moving step to the phase change RAM area" 43 for moving the phase change RAM area 11 so that the phase change RAM area 11 can be irradiated, and the "user information reproducing step" 44 for reproducing the user information from the optical recording medium 20 by the management information. At least

Note that not the user information but the operating system information is recorded in the ROM area 12.
By adopting such a recording / reproducing method, information can be processed with high reliability and high density.

This is because the phase change recording film can be recorded at a high density, but has the drawback that its signal characteristics deteriorate if it is repeatedly recorded, and the magneto-optical recording film is repeatedly recorded. Even though the signal characteristics are not deteriorated, there is a drawback that high density recording is not possible, and in consideration of the suspension of production of the optical recording medium, the optical recording medium and its recording / reproducing are comprehensively considered. It is the design of the method.

[0032]

The optical recording medium and the recording / reproducing method thereof according to the present invention are advantageous in that they can be easily manufactured and information can be recorded / reproduced with high reliability.

[Brief description of drawings]

FIG. 1 is a plan view showing a basic structure of an optical recording medium according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the basic structure of the optical recording medium of FIG.

FIG. 3 is a block diagram showing a recording / reproducing apparatus for an optical recording medium of the present invention.

FIG. 4 is a schematic process diagram showing a recording method of an optical recording medium of the present invention.

FIG. 5 is a schematic process diagram showing a reproducing method of the optical recording medium of the present invention.

FIG. 6 is a sectional view showing a conventional optical recording medium.

FIG. 7 is a front view showing a part of a conventional recording / reproducing apparatus for an optical recording medium.

[Explanation of symbols]

 10 magneto-optical RAM area 11 phase change RAM area 12 ROM area 13 pre-groove 14 pre-pit

Claims (3)

[Claims] 1. An optical recording medium including a RAM area for recording / reproducing information, and a ROM area for preliminarily forming information as an uneven pit row and only reproducing, wherein the RAM area is a magneto-optical RAM area. A phase change RAM area, the ROM area is disposed between the magneto-optical RAM area and the phase change RAM area, and the ROM
The region is free of the recording film in the magneto-optical RAM region and the recording film in the phase change RAM region, and the magneto-optical RAM region, the phase change RAM region, and the reflective layer in the ROM region are common. Optical recording medium. 2. A magneto-optical RAM area having a common reflection layer and capable of recording / reproducing information, a phase change RAM area capable of recording / reproducing information, and a ROM area capable of preliminarily forming information as a pit row having concaves and convexes and performing only reproduction. User recording information is recorded in the phase change RAM area, and management information or search information of the user recording information is recorded in the magneto-optical RAM area in a form that is not geometrical unevenness. Then, at the time of reproduction, the user record information is read from the phase change RAM area, and the management information or search information is read from the magneto-optical RAM area. 3. The magneto-optical RAM area includes a substrate, a magneto-optical recording film formed on the substrate, and a reflective layer formed on the magneto-optical recording film, and the phase change RAM area is A substrate, an optical phase change recording film formed on the substrate, and a reflective layer formed on the optical phase change recording film, wherein the ROM area is an uneven pit formed on the substrate. 2. A column comprising a row and a reflective layer coated thereon.
The optical recording medium described in 1.