JP2003141788A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record information peculiar for a magneto-optical disk without damaging the capacity of the disk. SOLUTION: In the magneto-optical disk, information peculiar for the disk composed of a pattern part composed of patterns having different reflection factors is provided in a portion, where no track exists, in the outer peripheral part of that disk. In the pattern part, when producing the magneto-optical disk, reflection films (dielectric layer, reproducing layer, intermediate layer, recording layer, dielectric layer and heat radiating layer or the like) are formed in the state of setting an outer peripheral ring 110 having a rugged part P on a substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc and an optical disc device.

[0002]

2. Description of the Related Art Optical discs, particularly magneto-optical discs, are rewritable data recording media, and are attracting attention as recording media having a large recording capacity and high reliability, and have been put to practical use as computer memories and the like. ing. Further, in recent years, ASs for the purpose of further increasing the capacity
-MO (Advanced Storage Magne)
The tOptical disk standard has been published and is about to be put to practical use. Furthermore, iD-P that is capable of high-density recording and is compatible with portable devices
Small magneto-optical disks such as HOTO have appeared.

[0003]

FIG. 4 shows an example of a sectional structure of a magneto-optical disk. Magneto-optical disk 1 shown in FIG.
0 is a transparent substrate 1 made of polycarbonate, and Si
A dielectric layer 2 made of N, a reproducing layer 3 made of GdFeCo, an intermediate layer 4 made of SiN, a recording layer 5 made of TbFeCo, a dielectric layer 6 made of SiN, and a heat dissipation layer 7 made of Al are laminated. The dielectric layer 2, the reproduction layer 3,
The intermediate layer 4, the recording layer 5, the dielectric layer 6, and the heat dissipation layer 7 constitute a magnetic film 310, and a protective layer made of an ultraviolet (UV) curable resin for preventing characteristic deterioration due to oxidation and scratches of the magnetic film 310. 8 is applied.

SiN forming the dielectric layer 2, GdFeCo forming the reproducing layer 3, and Si forming the intermediate layer 4.
N, TbFeCo forming the recording layer 5, SiN forming the dielectric layer 6, and Al forming the heat dissipation layer 7 are formed by a sputtering method or a vapor deposition method, and the ultraviolet curable resin forming the protective layer 8 is spin-coated. Etc. are applied.
The magneto-optical disk 10 is a so-called CAD (Center).
This is a disk used in the r Apertured Detection) method, and the details of the recording / reproducing principle of a signal with respect to the magneto-optical disk 10 will be omitted here.

Further, as shown in FIG. 5, the translucent substrate 1 has a disk shape, and a through hole H for clamping with a magneto-optical disk device is provided in the center thereof. When the dielectric layer 2, the reproducing layer 3, the intermediate layer 4, the recording layer 5, the dielectric layer 6, and the heat dissipation layer 7 are formed on the translucent substrate 1, oxidation of each layer is prevented and durability is improved. In order to improve the property, it is necessary to form the film while the outer peripheral portion and the inner peripheral portion of the disk are shielded by the outer peripheral ring 100 and the mask 200. At this time, the radius Kl of the transparent substrate 1 is larger than the inner diameter Nl of the outer ring 100, and the diameter M of the mask 200 is larger than the inner diameter Nl.
l is larger than the diameter of the through hole H in the center of the transparent substrate 1. Therefore, when a film is formed by a sputtering method, a vapor deposition method or the like with the outer peripheral ring 100 and the mask 200 set,
No film is formed on the innermost and outermost circumferences of the disc. After that, the protective layer 8 is formed by covering the region on the inner periphery where the film is not formed to the region on the outer periphery where the film is not formed with the ultraviolet curable resin.

However, when the protective layer 8 is formed, surface tension or the like acts on the ultraviolet curable resin, so that a portion 300 where the ultraviolet curable resin rises is formed on the outer peripheral portion of the disk as shown in FIG. The problem occurs. The side where the raised portion 300 is present is the side where the magnetic head MH is present, and the raised portion 30 is present.
When the magnetic head MH contacts 0, there is a risk of damaging the magnetic head MH, and since the magnetic head MH cannot be controlled to an appropriate position, recording cannot be performed up to the outer peripheral portion of the magnetic film 310. It cannot be used for recording / playback, and is also a cause of disk capacity reduction.

Further, as shown in FIG. 7, the magneto-optical disk 10 is provided with tracks for recording and reproducing signals, and in this example, grooves 40 are spirally formed from the outer circumference to the inner circumference. However, the groove 40 is referred to as a groove and the convex portion 45 on the substrate is referred to as a land, and these are formed in a data area in which a signal can be recorded and reproduced. Generally, in a magneto-optical disk, there is a portion 50 where the land 45 and the groove 40 are not formed on the outermost periphery thereof, which is called a mirror portion. As shown in FIG. 6, reproduction of a signal from the magneto-optical disk 10 is performed by laser light, and the laser light is emitted from the transparent substrate 1 side by the optical pickup PU and reproduced through the transparent substrate 1. Is done.

Further, for recording a signal on the magneto-optical disk 10, the laser beam on the transparent substrate 1 side and the laser beam on the opposite side with the transparent substrate 1 in between (that is, the protective layer 8 side). The magnetic field from the magnetic head MH at
However, as described above, the raised portion 300 of the ultraviolet curable resin is present on the mirror portion 50, and cannot be used for signal recording / reproduction as described above.

On the other hand, in a small magneto-optical disk,
There is a problem that the recording capacity becomes small because the area that can be used for recording and reproducing signals is small, and it is necessary to secure as many areas as possible for recording and reproducing signals. For this reason, it is conceivable to expand the area for recording / reproducing signals in the inner circumferential direction of the disc, but this is also limited because of the existence of the spindle motor SM (see FIG. 6) for rotating the disc (see FIG. 6). For example, even if the area can be physically provided, the spindle motor SM interferes and the optical pickup PU cannot be moved there.

Further, the outer peripheral direction of the disk is also restricted by the raised portion 300 of the protective layer 8 as described above. Further, in recent years, in order to regulate illegally copied discs and to manage discs after sale, it is necessary to include a manufacturing symbol or manufacturer information in advance on the disc, or data such as disc management information directly recorded / reproduced by the user. It is required to record fixed information other than the above, which may reduce the area of the disc that can be used by the user.

Here, as a technique for forming production management information and the like on a disc, there is one disclosed in, for example, Japanese Patent Laid-Open No. 2000-126319. According to this, "a pattern consisting of a portion having a reflection film or a recording film (metal film) and a portion having no recording film (metal film) is formed on a part of the innermost peripheral portion of the optical disk substrate. This bar code information (pattern) has a form of information and can be read by a predetermined reproducing device. For example, in a read-only medium, the contents of the recorded information and the rod number of the stamper are common. In addition to the information, board-specific information such as production date and media serial number is recorded.

Further, the restriction of copying permitted on the medium, for example, information on permission / non-permission is also recorded. If the area in which the barcode information is recorded is set as an area that can be accessed by a general reproducing apparatus, an optical disk medium having a function as a copy guard is obtained. ". Further, when the amount of reflected light is measured from the mirror portion 50 shown in FIG. 7 toward the inner circumference of the disk (the laser light is traced across the track), the amount of reflected light changes as shown in FIG. The mirror 50 has the largest amount of reflected light, and the land 45 and the groove 40
Is reduced in the area where the land is formed, and land 45 and groove 4
It can be seen that the balance change of 0 is repeated.

Further, the decrease in the amount of reflected light in the region where the mirror portion 50, the land 45 and the groove 40 are formed increases as the track pitch becomes narrower, and the fluctuation decreases when the land 45 and the groove 40 are optimally balanced. . This is because the light is scattered due to the existence of the land 45 and the groove 40, and the amount of scattered light increases as the track pitch becomes narrower.

Therefore, the object of the present application is to effectively utilize the mirror section 50 and form various information on the mirror section 50 at the time of manufacturing a disk.

[0015]

According to a first aspect of the present invention, in an optical disc having spiral or concentric tracks on a disc-shaped transparent substrate, reflection is made on a portion of the disc outer peripheral portion where no track exists. It is characterized in that it has a pattern portion formed of patterns having different rates.

The invention described in claim 2 is the optical disc described in claim 1, characterized in that the pattern portion is formed by the presence or absence of a metal film. Claim 3
The invention described in (1) is characterized in that in the optical disc described in (1), the pattern portion is formed by laminating a plurality of metal films. According to a fourth aspect of the present invention, in the optical disc of the third aspect, the pattern portion is formed by a difference in reflectance of each of the laminated metal films.

The invention described in claim 5 is the optical disc according to any one of claims 1 to 4, characterized in that disc-specific information is formed in the pattern portion. The invention described in claim 6 is the optical disc according to any one of claims 1 to 5, wherein the pattern portion is formed of a bar code. The invention described in claim 7 is an optical disk device for reproducing the optical disk according to any one of claims 1 to 4, wherein information peculiar to the disk in the pattern portion is optically reproduced, and based on the reproduced information. It is characterized in that it is provided with a control means for judging whether or not the optical disc is a regular disc.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. The laminated structure of magnetic films in the optical disc (magneto-optical disc) of the present invention is that shown in FIG. Since it is the same as, the detailed description will be omitted. However, it is not limited to this.

In the magneto-optical disk of the present invention, as shown in FIG. 1, the above-mentioned layers are formed on the transparent substrate 1 by using the outer peripheral ring 110 having the uneven portion P in the inner diameter portion. The uneven portion P is set so as to be positioned on the outermost mirror portion of the disc. This has the advantage that the amount of light reflected by the mirror portion is large and changes in reflectance can be detected easily, and it becomes possible to effectively use the outermost peripheral portion of the disk, which is conventionally unsuitable for recording.

Further, a track may be newly formed at the place where the uneven portion P is set so that tracking can be taken. As a result, as shown in FIG. 2, there are places where the film exists and places where the film does not exist in the track direction, and places where the reflectance greatly differs appear alternately. In any case, a pattern portion having a pattern with different reflectance is formed at the place where the uneven portion P is set.

Next, a method of decoding a change in reflectance into a signal will be described. Specifically, the data can be decoded by extracting the voltage of the reflected light amount and recognizing that the place where the reflectance is high is 1 and the place where the reflectance is low is 0. Here, in the signal of the unevenness P, in addition to the information necessary for management at the time of producing the disc, an ID indicating that the inserted disc is a proper one for the device in which the disc is used By including the number or the like as the information unique to the disc, it is possible to prevent the illegal use of the magneto-optical disc.

The timing of setting the outer peripheral ring 110 need not be the above timing. In particular, when a film, which causes deterioration due to oxidation or the like, has to be formed on the transparent substrate 1, the outer ring 100 is used instead of directly forming the metal film on the transparent substrate 1. First, the dielectric layer 2 is formed, and then the outer ring 11 is formed.
It is preferable to set 0 to form a portion having different reflectance on the dielectric layer 2.

When laminating a plurality of metal films such as the magneto-optical disk 10, the reflected light amount may be changed by utilizing the difference in reflectance between the metal films. Specifically, the reproducing layer 3 is GdFeCo and the heat dissipation layer 7 is Al.
Then, in the case of laser light with a wavelength of 650 nm, GdFe
The reflectance of Co is about 15%, and that of Al is 90% or more, which are very different. Utilizing this, after forming the dielectric layer 2, the outer ring is set to 110, the reproducing layer 3, the dielectric layer 4, the recording layer 5, and the dielectric layer 6 are sequentially formed, and then the outer ring 10 is formed again.
Instead of 0, the heat dissipation layer 7, that is, Al is formed. At this time, it is necessary to design the inner diameter Nl of the outer peripheral ring 100 to be larger than the inner diameter of the outer peripheral ring 110 so that Al is formed on the unevenness P on the outer periphery. In this case, FIG.
The "with film" part of the above corresponds to the part with Al, and the "no film" part corresponds to the part with GdFeCo.

Next, the operation of the magneto-optical disk device for recording / reproducing signals on / from these magneto-optical disks will be described with reference to the schematic block diagram of FIG. First, the magneto-optical disk 10 includes a rotating unit 71 including a spindle motor (not shown).
Be attached to. When the control unit 75 recognizes that the disc is mounted, the optical pickup 70 is moved to the outermost peripheral portion of the disc where the pattern portion (the portion formed by the unevenness P) where the signal is recorded due to the difference in reflectance exists. ,
The motor drive circuit 73 is operated to rotate the magneto-optical disk 10, and the frequency tachogenerator (FG) is used.
The rotation speed is controlled to an appropriate value via 74. When the rotation speed is controlled to an appropriate value, the reflected light amount is reflected from the value of the reflected light amount of the optical pickup 70 by the reflected light decoding unit 80 to be decoded into a signal. Management information and ID information of the magneto-optical disk are stored in the storage unit 90 in advance, and the control unit 75 compares the content data of the storage unit 90 with the signal decoded by the reflected light decoding unit 80, and, for example, the two match. Whether or not the inserted magneto-optical disk 10 is a disk having proper management information is determined. If it is determined that the magneto-optical disc 10 is an authorized disc, the disc can be used (recording / reproducing, etc.). On the other hand, if it is determined that the magneto-optical disc 10 is not a legitimate disc, use of the disc (recording / reproducing, etc.) is prohibited. At this time, a warning that the disc is not a legitimate disc may be displayed.

[0025]

As described above in detail, according to the present invention, it is possible to form information peculiar to a disc as a pattern portion composed of patterns having different reflectances by utilizing an area which is not normally used in the optical disc. It can be effectively used without damaging the disk capacity. Then, based on the information peculiar to the disc formed in this pattern portion, it can be determined whether or not the disc is a regular disc.

[Brief description of drawings]

FIG. 1 is a diagram showing an outer peripheral ring used for manufacturing an optical disc of the present invention.

FIG. 2 is a diagram illustrating reading of a pattern portion.

FIG. 3 is a circuit block diagram showing a configuration of an optical disk device of the present invention.

FIG. 4 is a diagram showing a film structure of a magneto-optical disk.

FIG. 5 is a view showing an outer peripheral ring used for manufacturing a conventional optical disc.

FIG. 6 is a diagram for explaining problems in a conventional optical disc and an optical disc device.

FIG. 7 is a diagram for explaining problems in a conventional optical disc and an optical disc device.

FIG. 8 is a diagram for explaining problems in a conventional optical disc and an optical disc device.

[Explanation of symbols]

1 Translucent substrate 2,6 Dielectric layer 3 playback layers 4 Middle class 5 recording layers 7 Heat dissipation layer 10 magneto-optical disk 40 Groove part 45 Land 50 Mirror section 70 Optical pickup 71 rotating part 73 Motor drive circuit 74 FG 75 Control unit 80 Reflected light decoding unit 90 Memory 100, 110 outer ring 200 shield 300 UV curable resin rise 310 Magnetic film MH magnetic head P uneven part PU optical pickup SM spindle motor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Tanase             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F-term (reference) 5D029 PA01                 5D075 AA03 CC33 DD01 EE03                 5D090 AA01 BB10 CC14 GG32 JJ11

Claims (7)

[Claims] 1. An optical disc having spiral or concentric tracks on a disc-shaped transparent substrate, wherein a pattern portion formed with a pattern having a different reflectance is provided on a portion of the outer peripheral portion of the disc where no track exists. Characteristic optical disc. 2. The optical disc according to claim 1, wherein the pattern portion is formed by the presence or absence of a metal film. 3. The optical disc according to claim 1, wherein the pattern portion is formed by laminating a plurality of metal films. 4. The optical disc according to claim 3, wherein the pattern portion is formed by a difference in reflectance of each of the laminated metal films. 5. The optical disc according to claim 1, wherein disc-specific information is formed on the pattern portion. 6. The optical disc according to claim 1, wherein the pattern portion is formed of a bar code. 7. An optical disc device for reproducing the optical disc according to any one of claims 1 to 6, wherein information peculiar to the disc in the pattern portion is optically reproduced, and the optical disc is reproduced based on the reproduced information. An optical disk device comprising a control means for determining whether or not the disk is a regular disk.