JP3304017B2 - Information recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium, such as an optical disk or an optical card, for recording information by optical characteristics, and more particularly to an illegal copy (transfer) of an optical disk or the like manufactured by a copyrighted publisher. The present invention relates to an information recording medium capable of identifying a board.

[0002]

2. Description of the Related Art As one of typical information recording media for recording information by providing optical characteristics, a CD-ROM (Compact Disc Read O), which is a kind of optical disc, is used.
nly memory).

[0003] Most CD-ROMs use a CLV (constant linear v) to record data using pits at regular intervals.
elocity) method. In the CLV system, constant angular levels are recorded using pits at intervals determined according to the radial position of the CD-ROM so that the angle with respect to the center of the CD-ROM is always constant.
OCT) method, the data capacity of the CD-ROM can be increased. In addition, CLV method and CA
Regardless of the V method, a frame is used as a recording unit in a CD-ROM. As shown in FIG. 16, frame 1
It is composed of fixed-length data and a synchronization signal 2 added to the head.

It is also possible to mix the CLV system and the CAV system on one optical disk.

For example, in the technique described in Japanese Utility Model Publication No. 5-44927, a recording area according to the CLV method and a recording area according to the CAV method are provided on an optical disc, and still image data and the like are recorded in the recording area according to the CAV method. I have. Also, in the technology described in Japanese Patent Publication No. 5-33470, CL
A recording area according to the V method and a recording area according to the CAV method are provided, and the position of each recording area is separately recorded as address information. Then, this address information is stored in the CLV
It is used for switching the rotation control of the disk motor between the recording area according to the CAV method and the recording area according to the CAV method.

[0006] Now, CD-ROMs are widely used for recording digital data such as recording various software, document data and image data.

[0007] Such various kinds of software and document data recorded on a CD-ROM are usually under the protection of copyright, but the production and sale of an illegal copy of a CD-ROM has hitherto been delayed. I did not refuse.

In particular, game software, books,
In the field of electronic publications such as dictionaries, illegal copying boards are often systematically produced, which has been a factor that hinders normal commercial transactions.

An optical disk such as a CD-ROM is
Production of copying machine is the shape of the recorded pit sequence on the information recording surface of the optical disk and templating using a plastic material or the like, be carried out by fabricating a master illegal copy board of the optical disk by using this person it can. However, in this molding technique, since it is necessary to remove the protective film of the optical disk and expose the pit array surface to form the mold, the shape of the pits is damaged in the process of removing the protective film, and accurate pitting is performed.
Often we cannot make a copy . In particular, it is extremely difficult to manufacture a copy board of an optical disk having a strong protective film.

[0010] Therefore, usually, reads the data of the normal of the optical disk, using the read data, to fabricate the master copy board of the optical disc as in the case of fabricating a legitimate optical disc is being carried out.

On the other hand, in order to prevent the production of such an optical disk of a copy disc, the copyright is conventionally displayed on the surface of the optical disk by engraving and printing characters, figures and the like.

Further, as a conventional technique for discriminating an optical disk of a copy disc, for example, the following technique is known.

That is, for example, the aforementioned synchronization signal 2
However, a technique described in Japanese Patent Application Laid-Open No. 4-286768 is known as a technique utilizing the fact that it cannot be read as data. In this technique, a part of the synchronization signal 2 described above is replaced in advance with another signal and recorded, and the presence or absence of the replacement signal is particularly detected at the time of reproduction. It is determined that the copyboard is illegal.

In Japanese Utility Model Laid-Open No. 2-20884,
It is disclosed that a visible pattern is formed on the surface of a signal recording layer of an optical disc. In addition, Japanese Patent Application Laid-Open No. 2-179994
Japanese Patent Application Publication No. JP-A-2005-17764 discloses that a visually recognizable pattern or the like is formed by changing a pit shape of a signal surface of an optical disc.

[0015]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 4-286 is disclosed.
According to the technology described in Japanese Patent No. 768, since the synchronization signal 2 itself including the replacement signal described above can be reproduced, an optical disk of an illegal copy disc on which the synchronization signal 2 including the replacement signal is recorded is used. Making is not so difficult.

According to the techniques described in Japanese Utility Model Laid-Open No. 2-20884 and Japanese Patent Laid-Open No. 2-17941, a process for forming characters, graphics, etc. is added separately in addition to a normal optical disk master manufacturing process. There is a need to.

[0017] Therefore, the present invention is conventionally and may be fabricated an original by the same fabrication process, the information recording medium of the illegal copy machine identifiable characters, graphic patterns appear is the illegal copy Release It is an object of the present invention to provide an information recording medium capable of easily recognizing the above. That is, the present invention provides an information recording medium in which the appearance of the information recording medium changes due to illegal copying.

[0018]

According to the present invention , there is provided a method for achieving the above object.
Ming has a recording surface with a plurality of recording tracks,
The pit row corresponding to the data is the first linear velocity CL
Light formed on the recording surface so that it can be read by the V method
A disc recording medium that has a pattern on a part of the recording surface.
Pattern recording area, and the first
It is formed when data is recorded by the CLV method with a constant linear velocity.
Visible through pit rows across multiple tracks
A specific notation that forms an optical reflection pattern of characters or graphics
Recording the recorded data.
The pit row shown is the first in the pattern recording area.
The second linear velocity, which is different from the linear velocity
Optical disc characterized by being formed at a recording position
A recording medium is provided. Furthermore, in order to achieve the above objectives,
Ming has a recording surface with a plurality of recording tracks,
The pit string corresponding to the data is the first rotation speed constant C
It is formed on the recording surface so that it can be read by the AV system.
An optical disk recording medium, wherein a part of the recording surface is patterned.
Pattern recording area, and the first
When recording data using the constant rotation speed CAV method,
Visible with pit rows across multiple tracks formed
Specification to form an optical reflection pattern of functional characters or graphics
Of the specific recording data.
The pit row indicating the data is located in the pattern recording area.
CAV with a constant second rotation speed different from the first rotation speed
Characterized in that the light is formed at a position recorded by the method
A disk recording medium is provided.

[0019]

According to the information recording medium of the present invention described above,
In the case of the original disc, the first track determined in advance by a specific tracking linear velocity control method for each track
In a copy board, when recording is performed under the control of the second tracking linear velocity according to a specific tracking linear velocity control method, the arrangement of a specific pit pattern corresponding to specific data is performed. Characters and graphic patterns can be represented on a copy board.
That is, if a copy board is manufactured by copying specific data in the pattern recording area, character and graphic patterns can be identified. Characters and graphic patterns can be distinguished by utilizing the difference in optical reflectance between regions caused by the arrangement of specific pit patterns.

A specific tracking linear velocity control method is applied to a CLV (constant) which records data at a constant tracking linear velocity.
It can be either an ant linear velocity (CV) method or a CAV (constant angular velocity) method for recording data at a constant rotation speed.

For example, two pits corresponding to a pit on a track on which the specific pit pattern is formed on a copy board and a pit on an adjacent track arranged perpendicularly to the tracking direction with respect to the pit pattern are: In the original version, two adjacent tracks
They are arranged offset from each other in the track direction with respect to the vertical direction. Due to the difference between the tracking linear velocities of the tracks on the original disc and the copy disc, the arrangement of the specific pit pattern is shifted, and characters and figures appear on the copy disc.

As described above, by recording specific data corresponding to a specific pit pattern, an identifiable pattern appears on an illegal copy board, and an illegal copy board can be easily identified. can do.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an information recording medium according to the present invention will be described below, taking as an example a case where the information recording medium is a CD-ROM, which is a kind of optical disk. Also,
A CD-ROM created from a master disc is called an original disc, and a CD-ROM created by copying the original disc is called a copy disc.

First, the principle of making characters and graphic patterns visible on a copy board using stored data will be described, and then, in each embodiment, the principle of making characters and graphic patterns invisible on the original board will be described. I do.

FIG. 1 shows a CD-ROM of a copy disk according to the present invention.
3 shows a signal surface of the ROM 4. On the signal surface of the CD-ROM 4 of the copy board, visible characters and graphic patterns 10 as shown in FIG. 1 appear. Character and figure pattern 10 is C
Data stored in the D-ROM, the copyright of the program, contents representing the copyright, data stored in the CD-ROM or the trademark of the CD-ROM itself, and other CD-Rs
It may represent data stored in the OM or contents of a right relating to the CD-ROM itself. However, of course, other than this may be used. letter,
The graphic pattern 10 is formed inside the character / graphic pattern area 14.

Hereinafter, a description will be given of the principle by which characters and graphic patterns can be viewed.

First, how the data is stored on the CD-R
A description will be given as to whether the information is recorded on the signal surface of the OM.

For example, a CD-ROM is a music CD.
The data is modulated by the EFM (eight to fourteen modulation) method used in the above and recorded on the signal surface by the CLV method.

That is, each 8-bit data shown in the left column of Table 1 is converted into a 14-bit EFM channel bit pattern shown in the right column of the table. Then, a 17-channel bit pattern is generated by adding 3 margin bits to the pattern, and this is used as a unit to be recorded on the CD-ROM.

[0030]

[Table 1]

Next, as shown in FIG. 2, the array is converted into an array of small projections (pits) having a predetermined width and height, and is recorded on an optical disk. The pit may be a small dent having a predetermined width and depth.

At this time, the data "1" of the channel bit pattern corresponds to the edge of each pit. For example, the 8-bit data “168” shown in Table 1 is replaced with “01”.
Since it is converted into an EFM channel bit pattern of "001001001001", the data "
1 ", so that the 8-bit data" 168 "
The pit pattern corresponding to includes two pits of 3T in length arranged at an interval of 3T, where T is the pit length corresponding to one channel bit.

On the other hand, similarly, the pit pattern corresponding to data "89" includes a pit having a length of 11T. In addition,
In the EFM modulation method shown in Table 1, the shortest pit length is 3
T, the longest is 11T.

On an optical disk, a light reflecting film such as an aluminum thin film is deposited on the entire surface of a pit portion and a non-pit portion (land portion), and a difference in the reflectance of light from the pit portion and the non-pit portion is detected. Are playing.

In the present embodiment, a character or figure pattern that can be viewed is formed on an optical disk by utilizing the difference in reflectance.

That is, due to the difference in reflectance between the pit portion and the non-pit portion, the average light reflectance differs between a certain pit pattern and a different pit pattern. Therefore, a certain pit pattern is collected into a desired character or graphic pattern shape, and a different pit pattern is arranged outside the character or graphic pattern.

In this embodiment, the pit pattern corresponding to the above-mentioned 8-bit data "168" and the data "8"
A pit pattern corresponding to 9 ″ is used.

FIG. 3 shows characters on the signal surface of the CD-ROM,
It is the figure which expanded a part of figure pattern. Here, the data constitutes a frame together with a synchronization pattern, information for error correction, and the like, and a pit pattern is created for this frame. Accordingly, a bit pattern corresponding to a synchronization pattern or a channel bit of information for error correction actually appears between bit patterns corresponding to data. However, the ratio is small for the bit pattern corresponding to the data. Therefore, in FIG.
For the sake of clarity, it is assumed that a frame is composed of only pit patterns corresponding to data. Also, pit patterns corresponding to the above-mentioned margin bits are omitted.

In the example shown, one of the character / graphic pattern 10 and its periphery shown in FIG. 1 is constituted by a pit pattern corresponding to data "168" including a pit 142 having a length of 3T, and the other is constituted by a pit pattern. It is composed of a bit pattern corresponding to data “89” including a pit 143 having a length of 11T. As described above, since the shortest pit length is 3T and the longest is 11T in the EFM modulation method, the difference in reflectance between the two pit patterns is the largest. For example, in the example shown in FIG. 1, the characters "LOGO"
The part of the graphic pattern 10 is composed of 3T, and the other parts (parts other than the characters and the graphic pattern in the character graphic pattern area 14) are composed of 11T.

In addition, two types of pit patterns corresponding to combinations of other data realizing another pit pattern having a difference in reflectance that is visually insignificant may be used. In addition, only one of the character and the graphic pattern and its surroundings is constituted by specific data, preferably, a pit pattern corresponding to data whose reflectance of the corresponding pit pattern is higher or lower than the average, and Alternatively, a set of pit patterns corresponding to a set of random data may be used. This is because pits are visually extremely small, and a set of pit patterns corresponding to a set of random data is considered to exhibit an average reflectance as a set. Further, one of the inside and the outside of the character or graphic pattern may be constituted by a pit pattern corresponding to a combination of a plurality of specific data. Further, both the inside and the outside of the character or graphic pattern may be configured by pit patterns corresponding to different combinations of a plurality of specific data.

As described above, a character or figure pattern can be formed using a pit pattern corresponding to normally used data. Conversely, formation of characters and graphic patterns is performed by recording ordinary data at the time of copying.

In addition, characters,
When a graphic pattern is recorded, the position is recorded so as to be controlled at a predetermined recording position using, for example, an encoder attached to a spindle motor of a disk or other measuring means.

By doing so, the CLV method,
In any of the CAV methods, a CD-ROM on which character and graphic patterns are formed is created at the time of copying.

Next, a description will be given in each embodiment of the principle of making it possible to make characters and graphic patterns invisible on the original board.

In the first embodiment, when a reproduction signal is read from a CLV optical disk (original disk) manufactured by a publisher having a copyright and copied by the CLV method, characters and / or graphic patterns appear on the copy disk surface. To As described above, for example, as this character or figure pattern,
In addition to the pattern representing the contents of the copyright of the information stored on the CD-ROM, the trademark given to the CD-ROM or the data stored in the CD-ROM, and the pattern representing other rights, etc. Characters or the like indicating that it is a board should be displayed. In the first embodiment, these pattern areas are added to the original disc.
The data is recorded by the CAV method, the other data portions are recorded by the CLV method, and when all of the data are copied by the CLV method, characters and graphic patterns appear on the copy board surface. Therefore, whether an optical disk is an original disk or a copy disk can be identified at a glance based on the presence or absence of a character or graphic pattern.

First, the reason why characters and graphic patterns cannot be seen on the original board but can be seen on the copy board will be described.

FIG. 4 is a diagram for explaining the radius of the CD-ROM. FIGS. 5A and 5B show the CDs.
An enlarged view of a track on -ROM, showing successive tracks T ₁ of the three adjacent to, T _2, T ₃ of the positional relationship of the pit. In addition, points A, B, and C in FIG. 5A are pit positions on tracks T ₁ , T ₂ , and T ₃ , respectively.
The pits are arranged in a line in the vertical direction (radial direction) and form the contours of characters and graphic patterns.
When they are aligned in a row or tilted to some extent, they become visible. In addition, if the pit of each track exists at a position inclined in the radial direction, and if the angle of the inclination is equal to or smaller than a specific value, visual identification becomes impossible.

When recording is performed by the CAV method, the length of one round of the track is as follows: if R is the radius of rotation of track T ₁ and p is the track pitch, 2πR for track T ₁ and 2π (R + p) for T _2. In T ₃ 2π (R + 2p), and the
It increases sequentially by 2πp. In the CAV system, each track 1
While the data recording capacity for each of the circumferences 2πR, 2π (R + p), and 2π (R + 2p) is equal, the CLV method has the same data recording capacity for each 2πR, for example. Therefore, when a CLV-type copy board is manufactured using the reproduction signal of the original board, the character / graphic pattern area of the CAV method is copied by the CLV method, so that the positional relationship of points A, B, C and the like changes. When this state is shown with reference to point A, as shown in FIG. 5 (a), point B is B 'delayed by one circumference difference ΔL = 2πp.
The point C moves to the point C 'delayed by 2ΔL.

FIG. 5B shows the positional relationship of FIG.
Points A, B ', and C' are rewritten so that they are arranged in the vertical direction. In FIG. 5B, assuming that the angle of the line segment ABC with respect to the track direction is θ, the outlines A,
This indicates that B and C are vertically arranged on the copy board as points A, B 'and C'. In other words, this means that a character or graphic pattern recorded in the CAV system at an angle θ with respect to the tracking direction on the original board becomes vertical on the copy board when copied in the CLV system.

The angle θ is given by the following equation (1), and is approximately 9 degrees irrespective of the track pitch p, the linear velocity, and the like.

Θ = tan ~ ¹ (p / ΔL) = tan ~ ¹ (１π) = 9.04 degrees (1) Since this inclination is almost horizontal, the characters and figure patterns are visually observed on the original board. It is difficult to identify and is not actually visible. Also, since the character and graphic patterns are vertical on the copy board, they can be visually identified.

[0052] In this embodiment, using this principle, the aforementioned character Original of the CLV system, a graphic pattern to the tracking direction, tilted ^{tan ~ 1 (1 / 2π)} ≒ 9 °, CA
Record in V format.

In the above description, the tracks T ₁ , T ₂ , T _3, etc. are obtained by approximating a perfect circle.
In the D-ROM, since tracks are formed in a spiral shape, the length of one round of each track slightly differs from the above value. As a result, the character and graphic patterns on the copy board are slightly distorted, but this distortion may be eliminated by correcting and recording the deviation of one circumference of each track in the spiral track.

Next, when producing the original master,
A description will be given of what tracking linear velocity should be used to record a character / graphic pattern recording area.

In the case where the angle θ has an inclination of about 9 degrees, in order to make characters and graphic patterns which cannot be seen on the original board visible on the copy board, the tracking linear velocity at the time of copying by the CLV method is as follows. It must match any of the tracking linear velocities in the CAV area of the original disc.

[0056] In Figure 5, the tracking linear velocity of the Original and the copy board matches with the point A of the track T _1. The track T ₁ is the CAV method character, because may be any track graphic recording area, matching the tracking linear velocity at the time of copying by the CLV method in any of the tracking linear velocity of the CAV system recording area That's all I need to do.

For this reason, in this embodiment, the tracking linear velocity at the time of copying is set within the tracking linear velocity range of the CAV recording area of the original disc.

FIG. 14 is a diagram showing the relationship between the tracking linear velocities at the time of producing the original disc and the copy disc. The horizontal axis indicates the tracking position, and the vertical axis indicates the tracking linear velocity. In the CAV method, the tracking linear velocity increases toward the outer periphery of the disk. Therefore, the tracking linear velocity of the original board increases in the character / graphic recording area,
It is connected to a flat CLV area that is a data recording area of the CD-ROM. CLV the playback signal of this original board
Fig. 14 shows the tracking linear velocity of the copy board recorded by the
As shown in (a), if the value falls within the tracking linear velocity range of the CAV area of the original disc, the character and graphic patterns appear on the copy disc.

On the other hand, as shown in FIG. 14B, when the tracking linear velocities of the original and copy discs do not intersect, the tracking linear velocity at the time of copying is lower than the tracking linear velocity of the CAV area of the original disc. This means that the characters and graphic patterns on the copy board are deformed by the Δv, which makes it difficult to identify them.

FIG. 15 shows the CA of the original disc on the CD.
FIG. 4 shows a tracking linear velocity characteristic diagram between a V region and a CLV data recording region.

In FIG. 15, the characteristic 30 is that the tracking linear velocity range of the CAV recording area is 1.2 to 1.4 m / s, which is the allowable linear velocity range defined by the CD standard.
Tracking linear velocity of 1.2 m / s at both ends
And the characteristics when connected to a CLV region of 1.4 m / s. The characteristic 31 indicates that the tracking linear velocity of the CLV area connected to both ends of the CAV recording area is 1.2.
The graph shows characteristics when the width is reduced by a predetermined width from .about.1.4 m / s.

In any case, since the tracking linear velocity in the CLV area falls within the linear velocity range in the CAV area, the above character and graphic patterns appear on the copy board. But,
In order to produce this CD stably, if the tracking linear velocities in both CLV regions fall within the standard value range of the CD as in characteristic 31, the tracking linear velocities in both CLV regions will fall outside the standard value range. Is practical because there is no

Next, the recording positions of the character and graphic patterns in the first embodiment will be described.

First, the radial width of the CAV recording area, that is, the character / figure pattern area on the original board is obtained.

[0065] As described above, one round length of the track T ₁ shown in FIG. 5 (b) 2.pi.R, because one round length of the outer tracks T ₂ are a 2π (R + p), for the T ₁ of the track T ₂ The tracking linear velocity increase rate is as shown in Expression (2).

[0066] Therefore 2π (R + p) / ( 2πR) = 1 + p / R (2), the tracking linear velocity increase ratio of the n-th track T _n counted from the track T ₁ is as shown in equation (3), the track The turning radius ratio between T ₁ and T _n is obtained.

[0067] Since the np in 2π (R + np) / ( 2πR) = 1 + np / R (3) Equation (3) is the width from the track T ₁ to T _n, a character corresponds to the width of the graphic recording area.

On the other hand, the tracking linear velocity range permitted for a CLV type CD-ROM is 1.2 to 1.4 m / s.
It is. Since the tracking linear velocity when copying the original disc by the CLV method is also set within the above-mentioned allowable range, the tracking linear velocity increase rate of the character and graphic recording areas of the original disc shown in the equation (3) is determined by the linear velocity range. Should be matched. That is, when the tracking linear velocity increase rate within the tracking linear velocity range is obtained from Expression (3), the following relationship is established.

1 + np / R = 1.4 (m / s) /1.2 (m / s) ≒ 1.17 (4) From this, the width np of the character / graphic recording area is given by equation (5).

[0070] np = 1.17R (5) Equation (5) means that there is a character, it must be increased in proportion to the width np graphic recording area radius R of the Original tracks T ₁ . Therefore, the larger the character and graphic recording area is provided on the outer peripheral side of the original board, the larger the width np is required. However, the width np may be such that the characters and graphics can be identified well. For this reason, the arrangement position of the character and graphic recording areas in the optical disk can be set as follows.

FIG. 9 shows a CD used for a CD-ROM or the like.
FIG. In FIG. 9A, data is sequentially recorded from a position of a program start diameter (φ50 (mm) or less, unit omitted) to a position not exceeding a program maximum diameter (φ116) at the maximum in a circumferential direction. Therefore, when the data amount is small, the outside diameter of the program area is inside the maximum diameter of the program, and this is called a program out diameter. A lead-out area for recording "0" data is provided outside the program-out diameter.

The TOC (table of content) is provided between the lead-in start diameter (φ46) and the program start diameter.
t: record data index information in the program area), and this TOC is called a lead-in area.
Normally, both the inside of the lead-in area and the outside of the lead-out area are mirror surfaces. Since there is no pit on the mirror surface, the optical pickup cannot perform the focusing operation and the tracking operation.

If the character and graphic recording areas of the original board are arranged in the program area, the data storage capacity of the CD-ROM is reduced. Therefore, in this embodiment, the area inside the lead-in area and the area outside the lead-out area are located. A character / figure recording area is provided in at least one of them.

When writing outside the lead-out area, since the lead-out diameter is φ117, from the equation (5),
Program out diameter (117 / 1.17 = φ100)
Is required. As a result, the character / graphic recording area enters into the program area, and the data storage capacity of the CD-ROM is reduced.

On the other hand, when the character / graphic pattern recording area is provided inside the lead-in area, since the lead-in start diameter is φ46, the inner diameter of the character / graphic recording area is (46 / 1.17 = φ41). Becomes This φ41 is sufficiently outside the outer diameter φ33 of the clamp area necessary for clamping the disk.

Therefore, characters and graphic patterns can be easily written at a linear velocity ratio of 1.17 inside the lead-in area.
The data storage capacity of the CD-ROM is not reduced. Since the difference between the lead-in start diameter φ46 and the inner diameter φ41 of the character / graphic recording area is 5 mm, the width of the character / graphic recording area at this time is 2.5 mm, and the character / graphic is clearly identified. Is a reasonable width.

FIG. 11 shows characters inside the lead-in area.
FIG. 9C shows a top view of a CD disk provided with a graphic pattern recording area, and FIG. 9C shows a cross-sectional view at this time. FIG.
As shown in the figure, a character / graphic pattern recording area 20 having a width of 2.5 mm is written inside the lead-in area 21 so as not to penetrate into the program area 22 and the clamp area 23. Also, as shown in FIG. 9C, the lead-in start diameter and the character / figure pattern recording area 20
A thin mirror surface may be provided between them.

As shown in FIG. 9B, if the width of the lead-out area is sufficiently large, it is needless to say that a character or graphic pattern may be recorded in the lead-out area. .

When the data amount is small, character and graphic patterns can be recorded in the program area. When the data amount is small, a plurality of characters and graphic patterns can be provided.

As described above, the character and graphic patterns are recorded in the predetermined character and graphic recording area 20 by the CAV method at an angle of about 9 degrees with respect to the tracking direction. By copying the part in the CLV format, characters and graphic patterns can appear on the copy board. Original board letters,
The program area other than the graphic recording area 20 may be recorded by the CAV method instead of the CLV method.

Next, a second embodiment will be described.

In the second embodiment, when a reproduction signal is read from a CAV or CLV optical disc (original disc) manufactured by a publisher having a copyright and copied by the CAV scheme, a character corresponding to the copyright is displayed on the copy board surface. And graphic patterns. In the second embodiment, these pattern area portions are recorded on the original disc by the CLV method, and other data portions are recorded by the CAV method or the CLV method.
When the pattern area is recorded in the CAV format, characters and graphic patterns appear on the copy board (other data portions are copied in the CAV format or CLV format). . Therefore, whether the optical disk is an original disk or a copy disk can be identified at a glance based on the presence or absence of the character and graphic patterns.

In such a case, the reason why characters and graphic patterns cannot be seen on the original board but can be seen on the copy board will be described.

FIG. 6 shows the characters of the original and copy discs,
FIG. 3 shows a partially enlarged view of a track of an optical disc for explaining a positional relationship between graphic patterns. As shown in FIG. 5 in the first embodiment, in FIGS. 6A and 6B, T ₁ ,
T ₂ and T ₃ are enlarged views of three adjacent tracks on the disk 4. In FIG. 6A,
Points A, B, and C are respectively tracks T ₁ , T ₂ , T ₃
The upper pit position, when the pits are arranged in a line in the vertical direction (radial direction) and form the contours of characters and graphic patterns. Becomes visible. In addition, if the pit of each track exists at a position inclined in the radial direction, and if the angle of the inclination is equal to or smaller than a specific value, visual identification becomes impossible.

For the length of one round of the track, R is the track T ₁
The radius of rotation, when the p is the track pitch, the tracks T ₁ 2.pi.R, the _{T 2 2π (R + p)} , the T ₃ 2
π (R + 2p), and sequentially increases by 2πp.

In the CLV system, for example, the data recording capacity for each 2πR is equal, whereas in the CAV system, the data recording capacity for each track circumference 2πR, 2π (R + p), 2π (R + 2p) is equal. Therefore, if a copy disc of the CAV system is manufactured using the reproduced signal of the original disc, the CLV
Since the characters and graphic patterns of the method are copied by the CAV method, the positional relationship of points A, B, C and the like changes. When this state is shown with reference to point A, point B moves to point B ', which is advanced by a circumference difference ΔL = 2πp as shown in FIG.
The point moves to a point C ′ advanced by 2ΔL.

FIG. 6B shows the positional relationship of FIG.
Points A, B ', and C' are rewritten so that they are arranged in the vertical direction. Assuming that the angle of the line segment B'C 'with respect to the tracking direction is θ, the outlines A, B, and C of the characters and the graphic patterns recorded at the angle θ on the original board are points A, B', This indicates that they are arranged in the vertical direction like C ′. In other words, this means that characters and graphic patterns recorded in the CLV system at an angle θ with respect to the tracking direction on the original board become vertical on the CAV copy board.

The angle θ is given by Expression (6), and is approximately 171 degrees regardless of the track pitch p, the linear velocity, and the like.

Θ = 180-tan ~ ¹ (p / ΔL) = 180-tan ~ ¹ (1 / 2π) ≒ 171 degrees (6) Since this inclination is almost horizontal, characters and graphic patterns are not It is difficult to visually identify and is not actually visible. Also, since the character and graphic patterns are vertical on the copy board, they can be visually identified.

In this embodiment, by using this principle, characters and graphic patterns are written on the original disc of the CAV system or CLV system in the tracking direction by 180-tan- ¹ (1 / 2π) 1 /.
Tilt at 171 degrees and record in CLV format.

In the above description, the tracks T ₁ , T ₂ , T _3, etc. are obtained by approximating a perfect circle.
Since tracks are formed in a spiral shape in the D-ROM, the length of one round of each track slightly differs from the above value. As a result, the character and graphic patterns on the copy board are slightly distorted, but this distortion may be eliminated by correcting and recording the deviation of one circumference of each track in the spiral track.

Next, at the time of producing the original master,
A description will be given of what tracking linear velocity should be used to record a character / graphic pattern recording area.

In the case where the angle θ has an inclination of about 171 degrees, in order to make characters and graphic patterns which cannot be seen on the original board visible on the copy board, the tracking linear velocity at the time of copying by the CAV method is as follows. Original Edition CL
It must match any of the tracking linear velocities in the V region.

[0094] In Figure 6, the tracking linear velocity of the Original and the copy board is coincident with the track T _1. The track T ₁ character, because may be any track graphic recording area, a character when copying Original the CAV method, the tracking linear velocity of graphic recording area of the Original characters, graphic recording area Should be matched to any of the tracking linear velocities.

That is, the rotational speed range permitted for the CAV optical disk is set to N _{1 to} N ₂ (N ₁ <N ₂ ) (rps;
And the radius of the character / graphic pattern recording area recorded on the original board is R _{1 to} R ₂ (R ₁
<When R _2), the tracking linear velocity range of the radius R ₁ to R ₂ in the area of the optical disk copying this Original at a rotational speed N ₁ becomes like the characteristic 100 shown in FIG. 8, at a rotation speed N ₂ When copied, the characteristic is as shown in FIG.

Since the copy board is manufactured with its rotation speed in the range of N _{1 to} N ₂ , the tracking linear velocity of the character / figure recording area of the original board is set to the characteristic 1 shown in FIG.
If it is set within the range where 00 and the characteristic 101 overlap, the tracking linear velocity between the copy disc and the original disc always matches somewhere in the character and graphic recording area, and the characters and graphic patterns that cannot be seen on the original disc. Will be visible on the copyboard.

In FIG. 8, in order to secure the character and graphic recording areas on the original board, the tracking linear velocity range characteristic 100 and the tracking linear velocity range characteristic 101 must be aligned. It suffices if the following relationship is satisfied.

It is necessary that 2πR ₁ N ₂ <2πR ₂ N _1, ie, N ₂ / N ₁ <R ₂ / R ₁ . Therefore, in this embodiment Original character set to be larger than the radius ratio of the graphic recording region (R ₂ / R ₁₎ the allowable rotation speed ratio of the optical disc of the CAV system (N ₂ / N _1).

Next, the recording positions of the character and graphic patterns in the second embodiment will be described with reference to FIG.

When the character and graphic recording areas of the original board are arranged in the program area, the data storage capacity of the CD-ROM is reduced. Therefore, in this embodiment, the area inside the lead-in area and the area outside the lead-out area are different. A character / figure recording area is provided in at least one of them.

Assuming that the allowable rotational speed ratio (N ₂ / N ₁ ) of the optical disk in the CAV system is 1.1, when writing outside the lead-out area, the lead-out diameter is φ117 as shown in FIG. The program out diameter is (φ11
7 / 1.1 ≒ φ106.4), and the character / graphic recording area penetrates into the program area, thereby reducing the data storage capacity of the CD-ROM.

On the other hand, when the character / graphic pattern recording area is provided inside the lead-in area, since the lead-in start diameter is φ46, the inner diameter of the character / graphic recording area is (46 / 1.1 ≒ φ42). And it is sufficiently outside the outer diameter φ33 of the clamp area required for clamping the disk.

Therefore, a character,
Graphic patterns can be easily written at an allowable rotation speed ratio of 1.1.
The data storage capacity of the D-ROM is not reduced.

Since the difference between the lead-in start diameter φ46 and the inner diameter φ42 of the character / graphic recording area is 4 mm, the width of the character / graphic recording area at this time is 2 mm.
The width is appropriate for clearly identifying characters and figures.

FIG. 12 shows characters inside the lead-in area.
1 shows a top view of a CD disk provided with a graphic pattern recording area. As shown in FIG. 12, a character / graphic pattern recording area 20 having a width of 2 mm is written inside the lead-in area 21 so as not to penetrate into the program area 22 and the clamp area 23. Further, a thin mirror portion may be provided between the lead-in start diameter and the character / graphic pattern recording area 20.

When the width of the lead-out area or the width outside the lead-out area can be sufficiently taken, a character or graphic pattern may be recorded inside or outside the lead-out area. Of course.

When the data amount is small, character and graphic patterns can be recorded in the program area. When the data amount is small, a plurality of characters and graphic patterns can be provided.

As described above, the character and graphic patterns are recorded in the predetermined character and graphic recording area 20 by the CLV method at an angle of about 171 degrees with respect to the tracking direction. CAV part
When copying by the method, characters and graphic patterns can be made to appear on the copy board surface. The program area other than the character / graphic recording area 20 on the original board may be recorded by any of the CAV method and the CLV method.

Next, a third embodiment will be described.

In the third embodiment, when a reproduction signal is read from a CLV optical disk (original disk) manufactured by a publisher having a copyright and copied by the CLV system, a character or graphic pattern related to the copyright is printed on the copy disk surface. To appear. In the third embodiment, on the original disc, these pattern area portions are recorded by the CLV method, other data portions are recorded by the CAV method or the CLV method, and the pattern area portions are recorded by the CLV method. Copy with
Characters and graphic patterns are made to appear on the copy board (other data portions are copied by CAV or CLV). Therefore, whether the optical disk is an original disk or a copy disk can be identified at a glance based on the presence or absence of the character and graphic patterns.

In such a case, the reason why characters and graphic patterns cannot be seen on the original board but can be seen on the copy board will be described.

FIG. 7 is a partially enlarged view of a track of an optical disc for explaining the positional relationship between the original and copy discs with respect to the character and graphic patterns. As in FIG. 5 in the first embodiment described above, in FIGS. 7A and 7B, T
₁ , T ₂ , and T ₃ are enlarged views of three adjacent tracks on the disk 4.

In FIG. 7A, points A, B, C
Are the pit positions on tracks T ₁ , T ₂ , and T ₃ respectively. If the contours of the characters and graphic patterns recorded on the original disc by the CLV method are used, the CLV method When a copy disc is manufactured, points A, B, and C are generated due to a difference between the tracking linear velocity when the original disc is manufactured and the tracking linear velocity when the copy disc is manufactured.
Moves relatively on the copyboard, for example, at points A ', B', C '. That is, if there is a speed difference between the tracking linear velocity at the time of producing the original disc and the tracking linear velocity at the time of producing the copy disc, the pit interval will be shifted.

Similarly, depending on the difference between the tracking linear velocities at the time of production of the original disc and the copy disc, points A, B, and A which are arranged in advance on the original disc as shown in FIG.
In some cases, the Cs are vertically arranged on the copy board, such as points A ", B", and C ".

When the inclination angle θ of the points A, B, and C, which are the contours of the character and graphic patterns in FIG. 7B, approaches 0 degrees or 180 degrees, the characters and graphic patterns on the original board are shifted in the horizontal direction. , And cannot be visually discriminated. Characters and graphic patterns recorded on the original board invisibly in this way are marked with a point A on the copy board when the difference between the tracking linear velocities at the time of manufacturing the original board and the copy board becomes a predetermined value. ", B", C "
Are arranged in the vertical direction as shown in FIG.

In FIG. 7 (b), the distance ΔL at which point B moves to point B 'is defined as the tracking linear velocity at the time of producing the original disc, and the tracking linear velocity at the time of producing the original disc and the tracking at the time of producing the copy disc. The speed difference between linear velocities is Δ
If R is the radius from the center of rotation of the disk to the track T _2, then equation (7) is obtained.

ΔL = 2πR (Δv / v) (7) That is, the distance ΔL is determined by the linear velocity V
In the time of one rotation at, the master of the copy disc has linear velocity V + Δv
Is equivalent to the amount of deviation from one rotation of the rotation.

Accordingly, when the track pitch is p, the inclination angle θ is as shown in equation (8).

Θ = tan ~ ¹ (p / ΔL) (8) In this embodiment, by utilizing such a speed difference, a plurality of invisible characters in which pits are arranged at an inclination angle θ on the original board, Record the figure pattern. If the speed difference between the tracking linear velocity at the time of the copy board production and the tracking linear velocity at the time of the original board production becomes a value that is aligned in the vertical direction by correcting the inclination angle of each character and graphic pattern on the original board, the corresponding character Since the graphic pattern appears visually on the copy board, if a character or graphic pattern appears on the optical disc, it can be determined that the pattern is a copy board.

In order to be able to visually check, since the shortest pit length (3T) in the CD-ROM is 0.9 μm, ΔL
Is set to 0.9 μm or less, and the inclination θ is p = 1.6 μm
Then, from equation (8), it is necessary to set the range to 90 ± 29.4 degrees.

Accordingly, if the equation (7) is transformed into the equation (9), for example, and the tracking linear velocity v is 1.3 m / s and the radius R is 41.5 mm, the velocity difference becomes as shown below. Can be expressed.

Δv = ΔL × v / (2πR) = 4.5 × 10 ~ ⁶ (9) In this case, the tracking linear velocity of the copy board is 1.299.
If it is recorded in the range of 9955 m / s to 1.3000045 m / s, it will be visible. Conversely, if the original disc is manufactured at a tracking linear velocity of 1.29999955 m / s or less, or 1.3000045 m / s or more, it becomes invisible.

If the tracking speed of the copy board is unknown, it is only necessary to create character and graphic patterns at various tracking speeds for the original board. For example, as will be described later, it is possible to divide the area into a plurality of areas, and to record character and graphic patterns in each area at different tracking linear velocities.

In order to make characters and graphic patterns visible on a copy board, the tracking linear velocity is changed linearly so that the character and graphic patterns appear at any of the tracking speeds. Can be

In the above description, the tracks T ₁ , T ₂ , T _3, etc. are obtained by approximating a perfect circle.
Since tracks are formed in a spiral shape in the D-ROM, the length of one round of each track slightly differs from the above value. As a result, the character and graphic patterns on the copy board are slightly distorted, but this distortion may be eliminated by correcting and recording the deviation of one circumference of each track in the spiral track.

Next, the recording position of a character or graphic pattern in the third embodiment will be described with reference to FIG.

When the character and graphic recording areas of the original board are arranged in the program area, the data storage capacity of the CD-ROM is reduced. Therefore, in this embodiment, the inside of the lead-in area and the outside of the lead-out area are arranged. A character / figure recording area is provided in at least one of them.

When writing outside the lead-out area, as shown in FIG. 9, since the lead-out diameter is φ117, if a character / graphic pattern is recorded with a width of, for example, 5 mm, the character / graphic recording area will be within the program area. This will reduce the data storage capacity of the CD-ROM.

On the other hand, when the character / graphic pattern recording area is provided inside the lead-in area, since the lead-in start diameter is φ46, the inner diameter of the character / graphic recording area having a width of 2.5 mm is φ41, Is sufficiently outside the outer diameter φ33 of the clamp area required to clamp the outer diameter.

Therefore, in the lead-in area, characters,
Graphic patterns can be easily written, and the data storage capacity of the CD-ROM is not reduced. At this time, the width of the character / graphic recording area is a width appropriate for clearly identifying the character / graphic.

FIG. 13 shows characters inside the lead-in area.
1 shows a top view of a CD disk provided with a graphic pattern recording area. As shown in FIG. 13, a character / graphic pattern recording area 20 having a width of 2.5 mm is written inside the lead-in area 21 so as not to penetrate into the program area 22 and the clamp area 23. The character / graphic pattern recording area 20 is subdivided into areas 201, 202, and 203, and the character and graphic patterns can be recorded at different tracking linear velocities in each area. Characters and graphic patterns stored in these areas may be different from each other.

A thin mirror surface may be provided between the lead-in start diameter and the character / graphic pattern recording area 20.

If the width of the lead-out area or the width outside the lead-out area can be sufficiently taken, a character or graphic pattern may be recorded inside or outside the lead-out area. Of course.

If the data amount is small, character and graphic patterns can be recorded in the program area. When the data amount is small, a plurality of characters and graphic patterns can be provided.

As described above, the character and graphic patterns are recorded in the predetermined character and graphic recording area 20 by the CLV method, and the character and graphic recording areas 20 are copied by the CLV method with different tracking linear velocities. A character or a graphic pattern can appear on a copy board. The program area other than the character / graphic recording area 20 on the original board may be recorded by any of the CAV method and the CLV method.

Next, a fourth embodiment will be described.

In the fourth embodiment, when a reproduction signal is read from a CAV optical disk (original disc) manufactured by a publisher having a copyright and copied by the CAV scheme, a character or graphic pattern related to the copyright is printed on the copy disc surface. To appear. In the fourth embodiment, on the original disc, these pattern area portions are recorded by the CAV method, other data portions are recorded by the CLV method or the CAV method, and the pattern area portions are recorded by the CAV method. Copy with
Characters and graphic patterns appear on the copy board (the rest of the data is copied by CLV or CAV). Therefore, whether the optical disk is an original disk or a copy disk can be identified at a glance based on the presence or absence of the character and graphic patterns.

Also in this case, it is possible to use the shift in the pit position due to the difference in the tracking linear velocity between the original disc and the copy disc.

According to this embodiment, characters and graphic patterns are formed on the original board so that they cannot be seen.
An optical disc, such as a CD-ROM, on which a character and / or graphic pattern that can be viewed is formed can be obtained from a copy disc obtained by copying the original disc.

In each of the above embodiments, the CD-RO
Although the M disk has been described as an example, the same effect can be obtained by applying the invention to another optical information recording medium such as an optical card.

FIG. 10 shows the principle of recording / reproducing of an optical card.

The recording / reproducing method of the optical card includes a card rotating type shown in FIG. 10A, a head rotating type shown in FIG. 10B, a card reciprocating type shown in FIG. There is a beam scan type shown in FIG.

The card rotating type shown in FIG. 10A and the head rotating type shown in FIG. 10B adopt a signal recording system essentially similar to a CD-ROM. Therefore, similar effects can be obtained by applying the above-described embodiments as they are.

The card reciprocating type shown in FIG. 10C and the beam scan type shown in FIG.
It can be considered that a part of the rotational movement in is extracted, the arc-shaped track is linearized, and the one-way movement is changed to a reciprocation. Therefore, since the tracking directions are alternately reversed, the same effects as in the above-described embodiments can be obtained by recording the respective constituent points of the characters and graphic patterns on the original board at an angle with respect to the respective tracking directions. be able to.

In the first and third embodiments, in order to make characters and figures visible on the copy board, the deviation ratio (Δv / v) of the tracking linear velocity between the original board and the copy board is required. If the linear velocity is controlled to 1 × 10 to ⁶ or less, it is possible to prevent the displacement due to the difference in the tracking linear velocity.

As a method for judging whether the disc is an original disc or a copy disc except by visual observation, there is a method of pattern matching the pit position. Further, in the above-described first and second embodiments, the rotational speeds of a plurality of tracks in the character / graphic region are detected to determine the coincidence / non-coincidence, and whether the recording system of the character / graphic region is the CAV system or the CLV format is determined. By judging whether the disc is the system or not, it can be judged whether the disc is an original disc or a copy disc. Further, in the third embodiment, by determining the rotation speed in a certain track, the pattern is recorded at a speed at which characters and graphics can be viewed, and the pattern is recorded at a speed at which it cannot be viewed. Can be determined.

When a function is provided at the time of reproduction for judging whether or not the reproduced data and the collation data match, and if the data does not match, the reproduction cannot be performed. The data in the area must also be copied.

The embodiments of the present invention have been described above.

As described above, according to each embodiment of the present invention, characters and graphic patterns are formed so as to be invisible on the original disk, and characters and graphics which are visible on the copy disk obtained by copying the original disk. An optical disk such as a CD-ROM in which a pattern is formed can be obtained.

Further, when an optical disk of a copy disk is manufactured from such an optical disk of the original disk, characters and graphic patterns can be visually checked, and the copy disk is immediately identified visually. Thus, the effect of suppressing illegal copying can be expected.

Further, by recording each character and figure pattern on the outer periphery of the program-out diameter or the inner periphery of the lead-in start diameter of the information recording optical disc, the information recording capacity of the optical disc is impaired. Characters and graphic patterns can be recorded without using

Also, by recording the same character and graphic patterns on optical cards of various types, the same effects as in the case of an optical disk can be obtained.

[0153]

As described above, according to the present invention, an original disc can be produced by the same production process as in the prior art, an identifiable pattern appears on an illegal copy disc, and an illegal copy disc appears. Can be easily identified. In addition, characters and graphic patterns that cannot be identified are represented on the original board, and characters and graphic patterns that can be identified by copying appear. By doing so, the copy board can be visually identified.

[Brief description of the drawings]

FIG. 1 is a diagram showing an appearance of a CD-ROM according to the present invention.

FIG. 2 is a diagram showing the shape of a pit pattern of a CD-ROM according to the present invention.

FIG. 3 is a diagram showing a pit pattern of a CD-ROM according to the present invention.

FIG. 4 is a diagram showing a radial position of a track of a CD-ROM according to the present invention.

FIG. 5 is a diagram showing a pit positional relationship for each track of the CD-ROM according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a pit position relationship for each track of a CD-ROM according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a pit position relationship for each track of a CD-ROM according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a linear velocity characteristic of a CD-ROM according to a second embodiment of the present invention.

FIG. 9 is a diagram showing the arrangement of a character / graphic pattern area and a mirror portion of a CD-ROM according to the present invention.

FIG. 10 is a diagram showing a recording and reproducing method of an optical card.

FIG. 11 is a diagram showing character and graphic areas of a CD-ROM according to the first embodiment of the present invention.

FIG. 12 is a diagram showing a character / graphic area of a CD-ROM according to a second embodiment of the present invention.

FIG. 13 is a diagram showing character and graphic areas of a CD-ROM according to a third embodiment of the present invention.

FIG. 14 is a diagram showing a relationship between a tracking position and a tracking speed of the CD-ROM according to the first embodiment of the present invention.

FIG. 15 is a diagram illustrating a relationship between a tracking position and a tracking speed of the CD-ROM according to the first embodiment of the present invention.

FIG. 16 is a diagram showing frames recorded on a CD-ROM.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Frame 2 ... Synchronization signal 4 ... Optical disk 10 ... Character and graphic pattern 14 ... Character and graphic pattern area 142 ... 3T pit 143 ... 11T pit 20 ... Character / graphic recording area 21 ... Lead-in area 22 ... Program area.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tamotsu Ito 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi, Ltd. Image Media Research Laboratory (72) Inventor Takashi Takeuchi 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock (56) References JP-A-1-4933 (JP, A) JP-A-60-193143 (JP, A) JP-A-2-179994 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G11B 7/007 G11B 7/24 G11B 19/04

Claims (6)

(57) [Claims] A recording surface having a plurality of recording tracks;
The pit row corresponding to the recording data is equal to the first linear velocity.
Formed on the recording surface so that it can be read by a fixed CLV method
An optical disc recording medium , wherein a pattern recording area is provided in a part of the recording surface, and the first linear velocity CLV is provided in the pattern recording area.
Tracks formed when data is recorded by the method
Optics of characters or figures that can be seen with a row of pits in between
Recording data to form a specific reflection pattern
The pit string indicating the specific recording data is the pattern recording.
Constant second linear velocity different from the first linear velocity in the recording area
It is formed at the position recorded by CLV method.
Optical disk recording medium. 2. A method according to claim 1, wherein a pit string indicating the specific recording data is placed before the pit row.
CLV constant at the second linear velocity in the pattern recording area
The character is formed at the position recorded by the method.
Or that the optical reflection pattern of the figure has been made invisible
The optical disk recording medium according to claim 1, wherein: 3. The method according to claim 2, wherein the specific recording data is a first constant linear velocity.
Of a pit row formed when recording by the CLV method
Pit and the pit and the tracking direction
The pit immediately adjacent to the pit is the second linear velocity constant CLV.
When these are formed at positions recorded by the
The position of the vehicle is shifted in the track direction
Item 3. An optical disk recording medium according to any one of Items 1 to 2. 4. A recording apparatus having a recording surface having a plurality of recording tracks.
The pit row corresponding to the recording data is equal to the first linear velocity.
Formed on the recording surface so that it can be read by a fixed CLV method
An optical disc recording medium, comprising: a part of the recording surface;
A plurality of divided pattern recording areas are provided, and the first linear velocity
A plurality formed when recording data in a fixed CLV format
Characters visible by pit trains between tracks
Specific recorded data that forms the optical reflection pattern of the figure
The pit string indicating the specific record data is the pattern record.
Is different from the first linear velocity in the recording area.
Recorded in a constant linear velocity CLV method that differs for each pattern area.
Optical disc characterized by being formed at a recording position
recoding media. And a recording surface having a plurality of recording tracks.
The pit string corresponding to the recording data is the first rotation speed.
The recording surface is shaped so that it can be read out using a constant CAV method.
An optical disk recording medium formed, wherein a pattern recording area is provided in a part of the recording surface, and the first rotation speed constant CA is provided in the pattern recording area.
The multiple tracks formed when recording data in the V format
Light of characters or figures that can be seen by a pit row running between
Record specific recording data to form a biological reflection pattern
The pit string indicating the specific record data is the pattern record.
A second rotation in the recording area that is different from the first rotation speed
It is formed at the position where it is recorded by the constant speed CAV method.
An optical disk recording medium characterized by the following. 6. A pit row indicating the specific recording data is set in front of the pit row.
The second rotation speed constant CA in the pattern recording area.
By forming at the position recorded by the V method,
Making the optical reflection pattern of characters or graphics invisible
6. The optical disk recording medium according to claim 5, wherein: