JP2002279698A - Optical recording medium, method for manufacturing the optical recording medium, reproducing apparatus for the optical recording medium, and recording apparatus for the optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium in which regulating of recording/ reproducing of the optical recording medium, decipherment or the like can be performed with an existing recording/reproducing device of the optical recording medium and to provide a method of manufacturing the optical recording medium and the recording/reproducing device of the optical recording medium. SOLUTION: In an optical disk 10, a guiding groove 11 for recording which guides recording light and has a concentric circular shape or a spiral shape is provided in a recording region 12 on a substrate 10a, and a signal can be read by the change of the intensity of reflected laser light scanning the guiding groove 11 for recording. A helical pattern 13 which can be optically discriminated from other recording regions among recording regions 12 of the optical disk 10 and has a helical shape of a pitch width larger than that of the guiding groove 11 for recording and which crosses the guiding groove 11 for recording at least at one point when a complete round is made along the guiding groove 11 for recording is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to CDRW, CD-
The present invention relates to an optical recording medium such as R or DVD-R, DVD-RW, DVD + RW, a method for manufacturing these optical recording media, and a recording / reproducing apparatus for these optical recording media.

[0002]

2. Description of the Related Art At present, optical discs 1 such as compact discs, which are the most popular optical recording media, are used in addition to music applications which were originally used, optical recording media of personal computers, and optical recording media of moving images. It is also used as

[0003] Such an optical disk 1 is configured, for example, as shown in FIG.

That is, in the optical disc 1, a clamp area 3 which is clamped to the spindle of the optical disc recording apparatus is formed on the periphery of the center hole 2 so as to be concentric with the center 2a of the center hole 2 of the disc-shaped substrate 1a. Is provided.

In the optical disk 1, the PCA area 4 is further moved from the clamp area 3 in the outer diameter direction.
(Power Calibration Area),
PMA area 5 (Program Memory Are)
a), lead-in area 6, recorded area 7, unrecorded area 8,
Lead-out areas 9 are provided sequentially.

A recording guide groove called a groove is formed in each of these areas 4 to 9 so that the recording light is guided by laser light irradiation by exhibiting concentric circles or spiral shapes. I have.

Next, the operation of the conventional optical disc 1 will be described.

When recording on the optical disc 1, first, the PCA area 4 is irradiated with a laser beam, and P0 (optimum recording power) is determined by calibration (OPC).

Next, the laser beam irradiation with the optimum recording power is performed on the PMA area 5, and the record information in the memory is recorded on the PMA area 5.

If necessary, the contents of the PMA area 5 are stored in the lead-in area 6 by TOC (Table Of Table).
(Contents) (FixUp).

Next, when data recorded on the optical disc 1 is read, the data is read along the recording guide groove.
The recording light is guided by the laser light irradiation, and the recorded data is read by the change in the intensity of the reflected light.

Note that there is also known a write protect that is read-only in software.

As other types of optical disks and optical disk recording / reproducing devices, those described in Japanese Patent Application Laid-Open Nos. 9-306144 and 10-003694 are known.

[0014]

However, in such a conventional optical disc 1, illegal copying prevails due to high format compatibility, and protection of the copyright of software such as music, images, and programs has become a problem. ing.

Further, low security such as protection of information is also a problem.

To solve many of these problems,
A method is conceivable in which the optical disc 1 is discriminated by attaching an ID number, and based on the number, information is protected by controlling recording and reproduction, encryption, and the like.

However, since the production volume and the number of manufacturers of optical recording media are enormous, it is almost impossible to assign and manage unique numbers.

As an alternative, there is a method in which marking is performed on the optical disc 1 and thereby the recording medium is individualized. However, in such a conventional method, most of the information is recorded outside the recording / reproducing area, and in many cases, it cannot be determined by the current recording / reproducing apparatus of the optical recording medium.

Accordingly, an object of the present invention is to provide an optical recording medium capable of controlling recording and reproduction of an optical recording medium, encrypting the recording, and the like with a current recording and reproducing apparatus for an optical recording medium, and manufacturing the optical recording medium. It is an object to provide a method and a recording / reproducing apparatus for the optical recording medium.

[0020]

According to the first aspect of the present invention, there is provided a recording area on a substrate having a concentric or spiral recording guide groove for guiding recording light. In an optical recording medium in which a signal can be read by a change in the intensity of reflected light of a laser beam that has caused the recording guide groove to scan, in the recording area of the optical recording medium, it becomes possible to optically distinguish it from other recording areas. A light having a spiral pattern having a pitch width wider than that of the recording guide groove, and having a spiral pattern crossing at least one or more of the recording guide groove when making a round along the recording guide groove. It features a recording medium.

According to the first aspect of the present invention, among the recording areas of the optical recording medium, a spiral pattern optically distinguishable from other recording areas is wider than the recording guide groove. It has a spiral shape with a pitch width and exists in an area where data is recorded.

For this reason, regulation of recording / reproduction of an optical recording medium,
Encryption and the like can be performed by a current recording / reproducing apparatus for an optical recording medium, and individual identification of the optical recording medium can be performed at low cost.

According to another aspect of the present invention, the reflectance of the spiral print is determined from the central value of the maximum value and the minimum value of the reflectance of the recording guide groove that crosses the spiral print. 2. The optical recording medium according to claim 1, wherein said optical recording medium has a reflectivity different by 5% or more.

According to the second aspect of the present invention, the reflectance of the spiral print is determined from the central value of the maximum value and the minimum value of the reflectance of the recording guide groove that crosses the spiral print. Since the reflectivity of the central value differs by 5% or more, the spiral pattern can be easily identified.

According to the third aspect,
3. The optical recording medium according to claim 1, wherein the pitch of the spiral pattern is 10 μm or more and 250 μm or less.

According to the third aspect of the present invention, since the pitch of the spiral pattern is 10 μm or more and 250 μm or less, the spiral pattern can be easily formed without deteriorating the quality of the recording signal. It is.

According to a fourth aspect of the present invention, there is provided the optical recording medium according to any one of the first to third aspects, wherein the recording layer in the recording area is made of a phase change material. Features.

According to the fourth aspect of the present invention, the production tact of the optical recording medium can be reduced.

Further, according to the fifth aspect, the reflectance of the recording medium is 30% or less.
An optical recording medium according to any one of the above items.

According to the fifth aspect of the present invention, since the reflectance of the recording medium is 30% or less, the spiral pattern can be easily identified.

According to another aspect of the present invention, the step of forming the recording layer in the recording area is performed by first forming an amorphous structure and then crystallizing the recording layer. 2. A crest is formed.
A method of manufacturing an optical recording medium according to any one of the first to fifth aspects is characterized.
According to the sixth aspect of the present invention, since the spiral pattern is formed during the crystallization process, the production time of the optical recording medium can be reduced.

Further, according to the present invention, with respect to the optical recording medium, the distance between the center of the spiral pattern and the center of the recording guide groove for guiding the recording light is determined based on the distance. 6. The recording / reproducing apparatus for an optical recording medium according to claim 1, wherein the optical recording medium is discriminated, and the result of the discrimination is to record numerically or coded data in the recording area.

According to the seventh aspect of the present invention, a spiral pattern, which is a physical characteristic, is recorded as data.

Further, in the optical recording medium according to the present invention, the distance between the center of the spiral pattern and the center of the recording guide groove for guiding the recording light is determined with respect to the optical recording medium. The optical recording according to any one of claims 1 to 5, wherein the optical recording medium is determined, and a numerical value obtained as a result of the determination or coded data is compared with a recorded content recorded in the recording area. It features a medium recording / reproducing device.

[0035] In the recording medium according to the eighth aspect, the optical recording medium is discriminated, and a numerical value or coded data as a result of the discrimination is recorded in the recording area. By being compared with the contents, the characteristics of the spiral print that has been converted into data can be used for various applications.

According to the ninth aspect,
For the optical recording medium, based on the distance between the center of the spiral print and the center of the recording guide groove for guiding the recording light, the optical recording medium is determined, and the numerical value or the value of the result of the determination is determined. The optical recording medium recording apparatus according to any one of claims 1 to 5, wherein the encoded data is recorded using the encoded data as an encryption key.

According to the ninth aspect of the present invention, the optical recording medium having the spiral pattern can be used as an inexpensive security system.

Further, according to the tenth aspect,
With respect to the optical recording medium, the optical recording medium is determined based on the distance between the center of the spiral print and the center of the recording guide groove for guiding the recording light, and the resulting numerical value or coded data is used. The reproduction apparatus according to any one of claims 1 to 5, which reproduces the encrypted data by using the decryption key as a recovery key.

According to the tenth aspect of the present invention, the reproducing apparatus reproduces the encrypted data by using the discrimination data of the optical recording medium as a restoration key. Therefore, the optical recording medium can be used as an inexpensive security system.

[0040]

FIG. 1 to FIG. 5 show an optical recording medium, a method for manufacturing the optical recording medium, and a recording / reproducing apparatus for the optical recording medium according to Embodiment 1 of the present invention. Note that the same or equivalent components as those of the conventional example are denoted by the same reference numerals and described.

First, the structure will be described. In the optical disk 10 according to the first embodiment, as shown in FIG. 1, the optical disk 10 is formed so as to be concentric from the center point 2a of the center hole 2 of the substantially disk-shaped substrate 10a. A clamp area 3 to be clamped to the spindle of the recording apparatus is provided on the periphery of the center hole 2.

The optical disc 10 further includes a recording area 12 having the PCA area, the PMA area, the lead-in area, the recording area, the lead-out area, and the like from the clamp area 3 further in the radial direction. They are sequentially provided substantially concentrically.

In this recording area 12, a recording guide groove 11 called a groove is formed in the recording layer, and data can be recorded and erased in the recording guide groove 11 by irradiating a laser beam. It may be configured.

However, when the optical disc 10 of the present invention is applied to a rewritable phase-change type compact disc (CD-RW), it is desirable that the following specific conditions are given.

The condition is that the width of the recording guide groove 11 formed on the substrate to be used is 0.25 to 0.65 μm, preferably 0.30 to 0.60 μm, and the depth of the guide groove is
50 to 550 °, preferably 200 to 450 °.

The quality required of the optical disk 10 used in the present invention, particularly the phase-change type optical disk, is not only required to simply record and erase, but also required to be signal reproduction stability and signal life.

In order to satisfy these requirements comprehensively and to achieve a recrystallization linear velocity of 5.0 to 10.0 m / s, at least the constituent elements of the recording layer are mainly composed of Ag, In, Sb, and Te. Yes, each composition ratio α, β, γ, δ, ε, (atomic%)
Is 0 <α ≦ 10, 2 ≦ β ≦ 12, 55 ≦ γ ≦ 70,
It was necessary that 2 ≦ δ ≦ 32 and α + β + γ + δ + ε = 100.

Ag is 10 at% or more and In is 12 at%.
As described above, when Sb is 70 at% or more, the reproduction stability of the signal and the life of the signal are insufficient.

Since the content of Te greatly affects the recrystallization linear velocity, it must be at least 22 at% or more and 32 at% or less even if controlled by the thickness of the recording layer or the thermal conductivity of other layers.

As a method for improving the reproduction stability of the signal and the life of the signal, the recording layer is composed of a 3B group and / or 4
It was effective to add an element selected from Group B and / or Group 5B.

The deterioration of the reproduction of the signal and the reduction of the life of the signal were caused by the crystallization of the amorphous mark. In order to suppress the crystallization of the amorphous mark, it was effective to add an element selected from Group 3B and / or Group 4B and / or Group 5B of the periodic table to the recording layer.

Although the mechanism is not clear, it is important that these additional elements suppress the crystallization of the amorphous mark by entering into a spatial gap between Ag, In, Sb, and Te or forming a chemical bond. It is considered.

Therefore, when the atomic radius is small, Ag,
An element having a large chemical bonding force with In, Sb, and Te or having many chemical bonds is effective. In particular, B, C, N,
Si, Ge, and Sn are effective.

The amount of these additional elements depends on the amount of 5a of the recording layer 12.
t% or less is effective. At 5 at% or more, Ag, I
This will affect the intrinsic recording / erasing characteristics of the n, Sb, Te recording layer 12 and cause unerasing.

The thickness of the recording layer 12 is 10 to 50.
nm, preferably 12 to 30 nm.

Further, in consideration of initial characteristics such as jitter, overwrite characteristics, and mass production efficiency, preferably 14 to 2
The thickness is preferably 5 nm. When the thickness is less than 10 nm, the light absorbing ability is remarkably reduced, and does not serve as the recording layer 12.

On the other hand, if the thickness is larger than 50 nm, uniform phase change at high speed is unlikely to occur. Such a recording layer 12 can be formed by various vapor deposition methods, for example, a vacuum deposition method, a sputtering method, a plasma CVD method, a photo CVD method, an ion plating method, an electron beam deposition method, or the like.

Among them, the sputtering method is suitable for mass production,
Excellent film quality.

In the first embodiment of the present invention, as shown in FIG. 1, a helical shape having a different reflectance from another recording area in a recording area 12 having a recording guide groove 11 is used as individual identification signals. , That is, a spiral pattern 13 is provided.

The spiral print 13 can be separated into individual recording media by the distance d between the center 13a of the spiral print 13 and the center 2a of the concentric or spiral recording guide groove 11 for guiding recording light onto the optical disk 10. Is what is done.

The easiest way to create a spiral pattern is to change the reflectivity by making the reflective state different from that of other areas due to the crystal structure or chemical change caused by laser light irradiation.

As a laser to be used, an LD mounted on a recording / reproducing apparatus for the optical disk 10 can be used.

In this case, the optical disk 10 can be created by moving the LD that emits DC light as recording light at a constant speed while rotating the optical disc 10 and without tracking.

Further, the recording layer of the recording area 12 is made of a phase-change recording material, and the recording layer once formed in an amorphous structure is crystallized by a laser beam or the like. In some cases, it is possible to form a spiral pattern in the crystallization step.

In this case, it is preferable to use an LD from the viewpoint of stable output and space saving of the device.

However, when an LD is used, it is necessary to move the LD and scan the entire recording area 12 of the optical disk 10 because the range of the output light is narrow. When this LD is used, it is also possible to create a spiral pattern in the crystallization step according to the intensity distribution, feed speed, output, etc. of the end face of the LD. The reflectivity of the spiral pattern can be adjusted by the output and intensity distribution of the LD light to be crystallized, particularly the intensity distribution at the end face of the LD light.

The pitch of the spiral pattern 13 can be adjusted by the moving speed of the LD to be crystallized.

In this case, the pitch of the spiral print 13 is set to 2 from the preferable range of the feed pitch to create the spiral print 13.
50 μm or less is preferable.

However, when the distance d between the centers 2a, 13a is calculated based on the number of the spiral prints 13 crossing the recording guide groove 11, the accuracy depends on the pitch of the spiral prints 13, and The distance d between the center of the spiral print 13 and the center 2a of the recording guide groove 11 can be calculated with higher precision as the pitch of 13 becomes smaller.

Therefore, the pitch of the spiral pattern 13 is 100
μm or less is more preferable.

On the other hand, if the spiral pattern 13 is too small, the number of traversing the recording guide groove 11 increases, and there is a possibility that the recording quality is degraded. Therefore, the pitch of the spiral pattern 13 is preferably 10 μm or more.

On the other hand, it is preferable that the reflectivity of the spiral print 13 is different from the average of the entire surface of the recording layer of the optical disk 10 by 5% or more because of the ease of distinguishing the spiral print 13.

As for the upper limit, if the reflectivity is largely different, the recording / reproducing quality of the optical disk 10 is affected.
% Is preferred.

By using the optical disk 10 having the above-described structure, the number of spiral prints 13 traversing the recording guide groove 11, that is, , Center 13a of spiral pattern 13
And the distance d between the recording guide groove 11 and the center 2a of the recording guide groove 11 can be checked.

The distance d between the center 13a of the spiral pattern 13 and the center 2a of the recording guide groove 11 is calculated by utilizing the fact that the recording guide groove 11 is substantially a perfect circle. A method of calculating from the number of spiral prints 13 crossing the recording guide groove 11 can be used.

According to this method, when the recording guide groove 11 is concentric, the track is shifted by one revolution, and when the recording guide groove 11 is spiral, the track is shifted along the recording guide groove 11. When the number of spiral prints 13 crossing the recording guide groove 11 in each circumference is examined, the center 13a of the spiral print 13 and the recording guide are calculated from the product of the maximum number of spiral prints 13 and the pitch of the recording guide groove 11. The distance d between the groove 11 and the center 2a is determined.

As shown in FIG. 6, the measuring device 14 for the spiral print 13 according to the first embodiment has an actuator for scanning the recording / reproducing LD 15 and the recording guide groove 11 with the LD light. 16 and its controller 1
7, a light receiving element 18 for measuring reflected light, a measuring circuit 19 for measuring a change in reflectance, and the like.
M drive, CD-R / RW drive, DVD-ROM
Drive, DVD-RAM drive, DVD ± R / RW
These are all provided in drives and the like.

That is, these drives are controlled by firmware and / or software capable of discriminating the spiral print 13 and the spiral print 1 that crosses the recording guide groove 11.
By using a counter device 20 that counts 3 or software, it is possible to execute various calculations based on the quantity counted by the counter device 20 so that the calculation means 21 provided in the measurement device 14 performs various calculations. A recording and reproducing apparatus according to Embodiment 1 of the present invention is configured.

Further, the distance d between the center 13a of the spiral print 13 and the center 2 of the recording guide groove 11 or the number of spiral prints 13 crossing the recording guide groove 11 for one round, or a coded value thereof Is recorded in the recording area 12 and a program for controlling recording and reproduction based on the value is used, so that the optical disc 10 and the recorded contents can be integrated, and illegal copying can be prevented.

Further, the distance d between the center 13a of the spiral print 13 and the center 2a of the recording guide groove 11 or the number of spiral prints 13 that traverse the recording guide groove 11 in one round, or a coded value thereof, is used. By using for encryption and decryption key,
It is possible to further enhance security.

Next, the operation and effect of the first embodiment will be described.

In the first embodiment, the optical disc 1
A spiral pattern 13 that can be optically distinguished from the other recording areas 12 in the recording area 12 of 0 has a spiral shape with a wider pitch width than the recording guide groove 11 and is recorded in an area where data is recorded. Exists.

For this reason, when the optical disk 10 is reproduced and the scanning of the optical disk 10 is performed along the recording guide groove 11 by the LD light due to the rotation of the optical disk 10, the optical disk 10 traverses the recording guide groove 11. When the spiral pattern 13 exists, the reflectance of the LD 15 for the LD light fluctuates and is received by the light receiving element 18. This variation is measured by the measurement circuit 19 and counted by the counter device 20.

The count number is calculated by the calculating means 21 so as to be used for the regulation of recording / reproduction specific to the optical disk, encryption, and the like.

For example, when the recording guide groove 11 is concentric, the track is shifted by one revolution, and when the recording guide groove 11 is spiral, each track is shifted along the recording guide groove 11. When the number of the spiral prints 13 crossing the recording guide groove 11 is examined, the maximum number of the spiral prints 13 and the recording guide groove 1 are determined.
The distance d between the center 13a of the spiral pattern 13 and the center 2a of the recording guide groove 11 is determined from the product of the pitch and the pitch of 1.

For this reason, the regulation of recording and reproduction of the optical disk 10, encryption and the like are performed by the current recording device of the optical disk 10,
This can be performed by a reproducing apparatus or a recording / reproducing apparatus, and individual identification of the optical disk 10 can be performed at low cost.

The reflectance of the spiral print 13 is 5% or more of the reflectance of the central value from the central value of the maximum value and the minimum value of the reflectance of the recording guide groove 11 traversing the spiral print 13. Since it is different, the spiral pattern 13 can be easily identified.

The pitch of the spiral pattern is 10 μm
Since it is 250 μm or less, the spiral pattern 13 can be easily formed without deteriorating the quality of the recording signal.

Further, since the recording layer of the recording area 12 is made of a phase change material, it is possible to reduce the production tact time of the disk 10.

Further, the reflectivity of the optical disk 10 is 30
%, The spiral pattern 13 can be easily identified.

Since the spiral pattern 13 is formed during the crystallization process, the production tact of the optical disk 10 can be further reduced.

Further, the spiral pattern 13 which is a physical characteristic is recorded as numerical data, and the optical disk 10 is discriminated, and the result of the discrimination or the coded data is stored in the recording area. By being compared with the recorded contents, the characteristics of the spiral print that has been converted into data can be used for various applications.

The optical disk 10 provided with the spiral print 13 can be used as an inexpensive security system.

Further, by configuring the reproducing apparatus to reproduce the encrypted data by using the discrimination data of the optical disk 10 as a restoration key, the optical disk 10
Can be used as an inexpensive security system.

As described above, by utilizing the variation in the position of the center 13a generated when the spiral pattern 13 is recorded as individual data of the optical disk, the production cost can be greatly reduced.

The functions required at the time of reproduction for recording the recording area 12 include a general CD-R / RW drive,
DVD-R, DVD-RW, DVD + RW drives are equipped with CD-R / RW, DVD-R, DVD-
Implementation is possible while maintaining high recording and reproduction compatibility of RW and DVD + RW media.

On the other hand, it is preferable that the reflectivity of the spiral print 13 differs from the average of the entire recording area 12 of the optical disk 10 by 5% or more because of the ease of distinguishing the spiral print 13.

Regarding the upper limit, if the reflectivity is largely different, the recording / reproducing quality of the optical disc 1 will be affected.
% Is preferred.

By using the optical disk 10 having the above structure, the number of spiral prints 13 traversing the recording guide groove 11, namely, Center 13a of spiral pattern 13
And the distance d from the center 2a of the recording guide groove 11 can be checked.

[0100]

EXAMPLE In the example of the first embodiment of the present invention, the effect of the first embodiment of the present invention was confirmed using a CD-R / RW as a general optical recording medium. Embodiment 1 of the present invention
Does not depend on the compact disk format, so that the DVD-R / RW, DVD having the recording guide groove 11 and performing recording / reproduction by changing the reflectance.
It can be similarly used for + R / RW and the like.

In the first embodiment, the optical disc 10 is a CD-R “Type74R” and a CD / -RW “CD-RW74” manufactured by Ricoh.
-AZ2 "was used.

The number of spiral prints 13 was measured by using the pulse reproducing DDU-1000 in the reproducing apparatus and counting the RF signals in the unrecorded area using appropriate thresholds.

FIG. 2 is a graph showing the production conditions, characteristics,
The evaluation is summarized.

In Examples 1 to 3, spiral prints 13 having different reflectivities were recorded on the respective optical disks 10, and the discrimination of the spiral prints 13 and the recording quality when the spiral prints 13 were subsequently recorded in the same area were examined.

The recording quality after recording was evaluated based on the BLER value.

In FIG. 2, recording method A uses a Ricoh CD
Using an R / RW drive “MP7040A”, a spiral pattern 13 was created by moving an LD that emitted DC light at a constant speed with the tracking removed while rotating the optical disc 10.

On the other hand, in the recording method B, POP120-Hitachi
4Ra and a feed amount of 60 μm / rotation, the recording area 12
The spiral print 13 was recorded while crystallizing the recording layer.

The reflectivity of the spiral print 13 was evaluated by the ratio of increase / decrease from the average of the reflectivity of the same circumference.

From these Examples 1, 2 and 3, it was confirmed that the spiral print 13 can be formed on each optical disk 10 regardless of the type of the recording layer.

Further, when the spiral print 13 is formed by the method B using a phase change material for the recording layer, the production tact is
Can be reduced to about half or less.

From the comparison between Example 3 and Comparative Example 1, spiral pattern 1
When the reflectance of the optical disk 10 is less than 5% of the reflectance of the optical disk 10, the reflectance of the spiral print 1 is affected by the in-plane variation of the reflectance.
3 becomes difficult to determine.

When the phase-change recording material was used for the recording layer, the variation in the reflectivity within the surface of the optical disk 10 was large at a reflectivity of 30% or more, and the spiral pattern 13 could not be discriminated.

FIGS. 3 and 4 show the relationship between the pitch of the spiral print 13 and the signal recording quality.

The BLER which is a standard of good recording quality is set to 10
In order to keep the pitch below 0 (f / s), the pitch of the spiral pattern 13 is
10 μm or more is preferred.

Embodiment 6 shown in FIG. 5 is used as a recording / reproducing apparatus.
In the seventh embodiment, the pickup of the DDU 1000 is used, and in the seventh embodiment, the pickup of the Ricoh CD-R / RW MP7060A is used. By counting the number of times that the threshold value set for each optical disc 10 is passed from the RF signal of each embodiment as the number of spiral prints 13, it was checked whether or not the spiral prints 13 can be distinguished in each playback device.

FIG. 5 shows the result of visually measuring the number of spiral prints 13 on an RF signal projected on an oscilloscope.
In the sixth and seventh embodiments, the optical disc 10 on which the spiral pattern 13 is recorded is described.
Is a result of measuring the number of spiral prints 13 of FIG.

In the sixth and seventh embodiments, the number of the spiral prints 13 can be sufficiently measured, and the distance d between the center 13a of the spiral print 13 and the center 2a of the recording guide groove 11 can be calculated. It was confirmed that.

Using Example 7, spiral pattern 1 of sample A
The signal encrypted by using Equation 3 of 3 was recorded on Sample A, and the number of spiral prints 13 of Sample A was measured in Example 7, and it was confirmed that the data could be decrypted using the key.

As a method of encryption, Caesar cipher which shifts each character code of the sample text by the number of spiral prints 13 was used, and the possibility of decryption was determined by comparing with the sample text.

Further, it was confirmed that the data of the sample A was copied to the sump B, and the number of the spiral prints 13 of the sample B could not be copied.

[0121]

As described above, according to the first aspect of the present invention, in the recording area of the optical recording medium,
A spiral pattern that can be optically distinguished from other recording areas has a spiral shape with a wider pitch width than the recording guide groove, and exists in the area where data is recorded.

For this reason, regulation of recording / reproduction of an optical recording medium,
Encryption and the like can be performed by a current recording / reproducing apparatus for an optical recording medium, and individual identification of the optical recording medium can be performed at low cost.

According to the second aspect of the present invention, the reflectance of the spiral print is determined from the central value of the maximum value and the minimum value of the reflectance of the recording guide groove crossing the spiral print. Since the reflectance differs by 5% or more, the spiral pattern can be easily identified.

[0124] According to the third aspect,
Since the pitch of the spiral print is 10 μm or more and 250 μm or less, it is possible to easily create the spiral print without deteriorating the quality of the recording signal.

Further, according to the fourth aspect, it is possible to shorten the production tact of the optical recording medium.

Further, according to the fifth aspect, since the reflectance of the recording medium is 30% or less, the spiral pattern can be easily distinguished.

Further, according to the sixth aspect, since the spiral pattern is formed during the crystallization process, it is possible to shorten the production tact of the optical recording medium.

Further, according to the seventh aspect, a spiral pattern, which is a physical characteristic, is recorded as data.

Further, according to the present invention, the optical recording medium is discriminated, and a numerical value of the discrimination result or
The coded data is compared with the recorded content recorded in the recording area, so that the characteristics of the helical print that has been converted into data can be used for various applications.

[0130] According to the ninth aspect,
The optical recording medium having the spiral pattern can be used as an inexpensive security system.

Further, according to the tenth aspect,
Since the reproducing apparatus reproduces the encrypted data using the discrimination data of the optical recording medium as the restoration key, the optical recording medium can be used as an inexpensive security system. It has a practically useful effect.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a recording area of an optical disc in an optical recording medium according to a first embodiment of the present invention.

FIG. 2 is a first example of an optical recording medium, a method for manufacturing the optical recording medium, and a recording / reproducing apparatus for the optical recording medium according to the first embodiment;
3 is a table illustrating differences between Comparative Examples 1 to 3. FIG.

FIG. 3 is a graph illustrating a relationship between a spiral print pitch and BLER of the optical recording medium according to the first embodiment, a method for manufacturing the optical recording medium, and a recording / reproducing apparatus for the optical recording medium.

FIG. 4 is a table illustrating the difference between Comparative Example 2 and Examples 4 and 5 in the example of the first embodiment.

FIG. 5 is a table showing Examples 6 and 7 of the first embodiment.

FIG. 6 is a block diagram illustrating a configuration of a recording / reproducing apparatus for the optical recording medium according to the first embodiment.

FIG. 7 is a partial cross-sectional perspective view illustrating the configuration of an optical recording medium.

[Explanation of symbols]

 2a Center of recording guide groove 10 Optical disk (optical storage medium) 10a Substrate 11 Recording guide groove 12 Recording area 13 Spiral pattern 13a Center of (spiral pattern) 14 Measuring device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 20/10 G11B 20/10 H 20/12 20/12

Claims (10)

[Claims] A concentric or spiral recording guide groove for guiding recording light is provided in a recording area on a substrate, and a signal can be read by a change in intensity of reflected light of a laser beam scanned on the recording guide groove. In the optical recording medium, among the recording areas of the optical recording medium, it becomes optically distinguishable from other recording areas, and exhibits a spiral shape having a pitch wider than the recording guide groove. An optical recording medium, comprising a spiral pattern which crosses at least one or more recording guide grooves when it makes a round along the guide grooves. 2. The method according to claim 1, wherein the reflectivity of the spiral print differs from the central value of the maximum and minimum reflectivities of the recording guide grooves crossing the spiral print by at least 5% of the reflectivity of the central value. The optical recording medium according to claim 1, wherein: 3. The pitch of the spiral pattern is 10 μm or more and 25 or more.
3. The optical recording medium according to claim 1, wherein the optical recording medium has a thickness of 0 μm or less. 4. The optical recording medium according to claim 1, wherein the recording layer in the recording area is made of a phase change material. 5. The optical recording medium according to claim 1, wherein said recording medium has a reflectance of 30% or less. 6. The method according to claim 1, wherein the step of forming the recording layer in the recording area is performed by first forming an amorphous structure and then crystallizing, and the spiral pattern is formed in the crystallization step. Item 6. The method for manufacturing an optical recording medium according to any one of Items 1 to 5. 7. An optical recording medium is determined with respect to the optical recording medium based on a distance between a center of the spiral pattern and a center of a recording guide groove for guiding recording light. 6. The recording device for an optical recording medium according to claim 1, wherein the result is recorded in the recording area as numerical or coded data. 8. The optical recording medium is discriminated based on a distance between a center of a spiral pattern and a center of a recording guide groove for guiding recording light. The result numerical value or coded data is compared with the recorded contents recorded in the recording area.
The reproducing apparatus for an optical recording medium according to any one of the above. 9. The optical recording medium is discriminated based on a distance between a center of a spiral pattern and a center of a recording guide groove for guiding recording light. The recording device for an optical recording medium according to any one of claims 1 to 5, wherein the encrypted data is recorded using a numerical value of the result or encoded data as an encryption key. 10. An optical recording medium is determined with respect to the optical recording medium based on a distance between a center of a spiral pattern and a center of a recording guide groove for guiding recording light. 6. The optical recording medium reproducing apparatus according to claim 1, wherein the encrypted data is reproduced by using the encrypted data as a recovery key.