JP2003196837A - Data recording medium, and method and device for data recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent pirated media from being produced by peeling by recording data needed for reproduction to a reflecting film. <P>SOLUTION: A pit which normally has a length 11T is divided into two pits P4 (4T) and P5 (4T) and a land L1 with a length 3T between them. Then the hatched land L1 between the two pits P4 and P5 is irradiated with a laser beam for additional recording. Consequently, the reflection factor of the land L1 decreases and after recording, the two pits are combined into one pit P7 when reproduced. The pit P7 has a length 11T and patterns (11T, 11T, 2T) of an original frame sink are formed after additional recording. An uneven pattern formed on a disk substrate after the reflecting film is peeled off does not constitute a regular frame sink, so a pirate media can not be manufactured by using this substrate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording medium, a data recording method, and a device applied to, for example, a read-only (ROM) type optical disc.

[0002]

2. Description of the Related Art The standard for a compact disc (CD), which is widely used today, is called compact disc audio (CD-DA), and is a standard document (Red Book).
It is based on the standard described in. On the basis of this standard, various formats including a CD-ROM have been standardized to form a so-called CD family. In the following description, when simply referred to as CD, CD
Discs of various formats included in the family are collectively referred to.

For a disk having a reflective film such as a CD, it has been proposed to record data such as identification information by irradiating the reflective film with a laser beam by selecting the material of the reflective film. By recording on the reflective film, it becomes possible to record, for example, identification information for identifying each disc. If you try to record identification information in the CD format, the CD
It is conceivable to use the Q channel subcode in the format.

In the CD standard, modes 1 to 5 are already defined as subcodes. Mode 1 records address information indicating a position on the disc as a time code, and is the most important one. Modes 2 and 3 are used to record a copyright code and the like.

[0005]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention A disc having a structure in which a concavo-convex pattern is formed on a disc substrate and a reflective film is coated on the disc substrate has a problem that an illegal pirated copy is produced by peeling. That is, there has been a problem that a pirated copy is manufactured by a method of illegally manufacturing a disk by peeling a reflective film from the disk and rebuilding a stamper using a disk substrate.

Therefore, an object of the present invention is to provide a recording medium, a data recording method and an apparatus capable of preventing illegal production of pirated copies by peeling.

[0007]

In order to solve the above-mentioned problems, the invention of claim 1 provides a reflective film in which a concavo-convex pattern corresponding to recorded information is formed on a track and whose characteristics can be changed by laser irradiation. The data recording medium is a covered data recording medium in which at least a part of a synchronization signal used for reproducing the recording medium is recorded by a recording method for a reflective film.

According to a fourth aspect of the present invention, there is provided a data recording medium in which a concavo-convex pattern corresponding to recording information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered. The area where at least part of the synchronization signal used for is recorded is an unrecorded area,
Alternatively, it is a data recording medium in which other data is recorded in the area and the synchronization signal can be recorded in the area by the recording method for the reflective film.

According to a sixth aspect of the present invention, there is provided a recording method for a data recording medium, wherein a concavo-convex pattern corresponding to recording information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered. It is a data recording method for recording at least a part of a synchronization signal used for reproducing a recording medium by the recording method. The invention of claim 7 is a data recording apparatus according to the recording method of claim 6.

According to an eighth aspect of the invention, in a recording method for a data recording medium, a concavo-convex pattern according to recording information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered. Data in which at least a part of the sync signal used for reproduction is recorded as an unrecorded area, or other data is recorded in the area and the sync signal can be recorded in the area by a recording method for the reflective film. It is a recording method. The invention of claim 9 is
A data recording device according to the recording method of claim 8.

According to the present invention, the synchronizing signal used for reproducing the recording medium is recorded by the recording method for the reflective film. Therefore, even if a stamper is formed from a substrate from which the reflection film is peeled off and a recording medium, that is, a so-called pirated plate is manufactured by the stamper, reproduction cannot be performed because the synchronization signal is not correctly recorded. This prevents pirated products from being manufactured.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. In order to facilitate the understanding of the present invention, the structure of an optical disc such as a CD will be described.

FIG. 1 is an enlarged view showing a part of an existing CD. A predetermined track pitch Tp (for example, 1.6
μm) tracks, recesses called pits and lands without pits are formed alternately.
The length of the pit and the land is within the range of 3T to 11T. T is the shortest inversion interval. On the CD
Laser light is emitted from the lower side.

The thickness is 1.
It has a structure in which a transparent disk substrate 1 of 2 mm, a reflective film 2 coated on it, and a protective film 3 coated on the reflective film 2 are sequentially laminated. The depth of the pit is λ so that the difference in light amount between the return laser light from the pit and the return laser light from the land is the maximum when the wavelength of the laser light is λ.
Selected as / 4. The reflective film 2 has a high reflectance. As will be described later, after the reflective film 2 is coated, information is recorded on the reflective film 2 by using laser light.

The flow of the manufacturing process of such a CD will be described with reference to FIG. In step S1, a glass master having a photoresist, which is a photosensitive material, applied to a glass plate is rotated by a spindle motor, and the photoresist film is irradiated with laser light that is turned on / off according to a recording signal to create a master. It The photoresist film is developed, and in the case of a positive type resist, the exposed portion is melted and an uneven pattern is formed on the photoresist film.

One metal master is prepared by electroforming the photoresist master plate by plating (step S2). A plurality of mothers are created from the metal master (step S3), and further a plurality of stampers are created from this mother (step S4). A disk substrate is created using the stamper. Compression molding, injection molding, photo-curing, and the like are known as methods for producing a disk substrate. Then, in step S6, a reflective film and a protective film are deposited. In the conventional disc manufacturing method, a CD is further manufactured by performing label printing.

On the other hand, in the example of FIG. 2, a step S7 of irradiating the reflection film with a laser beam to additionally record information.
Is added. In the land on the reflective film, atoms move due to heat treatment (thermal recording) irradiated with laser light, the film structure and crystallinity change, and the reflectance at that portion decreases. As a result, even if the land is irradiated with the laser light, the amount of the returned laser light is reduced and the reader recognizes the laser light as if it were a pit. Information can be recorded using this. In this case, the reflective film is made of a material whose reflectance changes by laser irradiation. Not only the material whose reflectance decreases but also the material whose reflectance increases due to recording are available.

Specifically, an aluminum alloy film Al
_The reflective film is composed of _100-x X _x . X, Ge, T
At least one element selected from i, Ni, Si, Tb, Fe and Ag is used. The composition ratio x in the Al alloy film is selected to be 5 <x <50 [atomic%].

Further, the reflection film may be composed of Ag _100-x X _x Ag alloy film. In that case, as X, at least one element of Ge, Ti, Ni, Si, Tb, Fe, and Al is used. Also, Al
The composition ratio x in the alloy film is selected to be 5 <x <50 [atomic%]. The reflective film can be formed by, for example, a magnetron sputtering method.

As an example, when a reflection film of AlGe alloy is formed with a film thickness of 50 nm and laser light is irradiated from the transparent substrate or the protective film side through the objective lens, the composition ratio of Ge is 20 [atomic%]. In the case of, the recording power is 6 to
In the case of 7 [mW], the reflectance decreases by about 6%, and in the case where the Ge composition ratio is 27.6 [atomic%], the reflectance is 7 when the recording power is 5 to 8 [mW]. ~ 8% lower. When such a change in reflectance occurs, additional recording can be performed on the reflective film.

Further, FIG. 3 shows a data structure of one frame of a conventional CD signal. In the CD, a parity Q and a parity P of 4 symbols are formed from a total of 12 samples (24 symbols) of digital audio data of 2 channels. 33 symbols (264 data bits) obtained by adding one symbol of the subcode to the total 32 symbols are treated as one lump. That is, in one frame after EFM modulation, a subcode of 1 symbol and 2
4 symbol data, 4 symbol Q parity, 4
It includes 33 symbols consisting of P parity of symbols.

EFM modulation method (eight to fourteen modu
lation: In EFM, each symbol (8 data bits)
Are converted into 14 channel bits. The minimum time width (time width in which the number of 0's between 1's and 1's of the recording signal is minimum) Tmin of the EFM modulation is 3T, and the pit length corresponding to 3T is 0.87 μm. The pit length corresponding to T is the shortest pit length. Further, 3 margin bits (also called combined bits) are arranged between each 14 channel bits. Furthermore, a frame synchronization pattern is added to the beginning of the frame. The frame synchronization pattern is 11T, 11T, where T is the cycle of channel bits.
And 2T are continuous patterns. Such a pattern does not occur in the EFM modulation rule, and the frame sync signal (hereinafter appropriately referred to as a frame sync) can be detected by a unique pattern. One frame has a total of 588 channel bits. The frame frequency is 7.35k
It is said to be Hz.

A collection of 98 such frames is a subcode frame (or subcode block).
Is called. The subcode frame, which is formed by rearranging 98 frames so as to be continuous in the vertical direction, includes a frame synchronization section for identifying the beginning of the subcode frame, a subcode section, and a data and parity section. It should be noted that this subcode frame corresponds to 1/75 second of the reproduction time of a normal CD.

This sub-code portion is formed of 98 frames. The first two frames in the sub-code part are the synchronization pattern of the sub-code frame and the out-of-rule of the EFM.
Pattern. Also, each bit in the sub-code portion constitutes a P, Q, R, S, T, U, V, W channel, respectively.

The R channel to the W channel are used for special purposes such as displaying still images and characters of so-called karaoke. Also, P channel and Q
The channel is used for the track position control operation of the pickup when reproducing the digital data recorded on the disc.

The P channel sends a signal of "0" in a so-called lead-in area located on the inner circumference of the disc, and a "0" and "1" at a predetermined cycle in a so-called lead-out area located on the outer circumference of the disc. It is used to record a signal that repeats and. The P channel is used to record a signal of "1" between each music piece and "0" in other areas in the program area located between the lead-in area and the lead-out area of the disc. Such a P channel is provided for finding the beginning of each music piece when reproducing the digital audio data recorded on the CD.

The Q channel is provided to enable finer control during reproduction of digital audio data recorded on a CD. Q channel 1
As shown in FIG. 4, the structure of the sub-code frame is composed of a synchronization bit part 11, a control bit part 12, an address bit part 13, a data bit part 14 and a CRC bit part 15.

The sync bit part 11 is composed of 2-bit data, and a part of the sync pattern described above is recorded therein. The control bit section 12 is composed of 4-bit data, and data for identifying the number of audio channels, emphasis, digital data, etc. is recorded therein. When this 4-bit data is "0000", it indicates 2-channel audio without pre-emphasis, when it is "1000", it indicates 4-channel audio without pre-emphasis, and when it is "0001", it indicates "1001" refers to 2-channel audio with pre-emphasis
In the case of, it means 4-channel audio with pre-emphasis. If the 4-bit data is "0100", it indicates a data track that is not audio. The address bit section 13 is composed of 4-bit data, and a control signal indicating the format (mode) and type of data in the data bit section 14 described later is recorded therein. CRC
The unit 15 is composed of 16-bit data and has a cyclic code (Cy
Data for detecting an error of clic Redundancy Check code (CRC) is recorded.

The data bit section 14 is composed of 72-bit data. When the 4-bit data of the address bit part 13 is "0001" (that is, mode 1), the data bit part 14 is configured to record the time code (position information) as shown in FIG. It That is, the data bit part 14 includes a track number part (TNO) 21, an index part (INDEX) 22, an elapsed time part (minute component part (MIN) 23, second component part (SEC) 24, frame number part (FRAME). ) 25) and the zero part (ZE
RO) 26 and the absolute time part (minute component part (AMIN) 27
, The second component part (ASEC) 28, and the frame number part (A
FRAME) 29)). Each of these parts is composed of 8-bit data.

The track number part (TNO) 21 is a 2-digit binary coded decimal (BC).
It is represented by D). This track number part (TNO) 21
"00" represents the lead-in track number, which is a track from which data reading is started, and "01" to "99" represent the track numbers corresponding to the numbers of each song or movement. Also,
The track number part (TNO) 21 is a hexadecimal number "A".
A "represents the number of the lead-out track, which is the track for ending the data reading.

The index part (INDEX) 22 has 2
It is represented by a digit BCD, "00" represents a pause, a so-called pause, and "01" to "99" represent subdivided tracks of each song or movement.

Minute component part (MIN) 23, second component part (SE
The C) 24 and the frame number part (FRAME) 25 are each represented by a 2-digit BCD, and a total of 6 digits represent the elapsed time (TIME) in each song or movement.
The zero part (ZERO) 26 has "0" added to all 8 bits.

Minute component part (AMIN) 27, second component part (A
SEC) 28, frame number part (AFRAME) 29
Is expressed in BCD of 2 digits each, and the absolute time from the first song (ATIME) with a total of 6 digits.
Represents

The data bit portion 24 in the TOC (Table of Contents) in the lead-in area of the disc
The structure of the track number part (TN
O) 31, point part (POINT) 32, elapsed time part (minute component part (MIN) 33, second component part (SEC) 3
4, consisting of a frame number part (FRAME) 35),
Zero part (ZERO) 36 and absolute time part (minute component part (P
MIN) 37, second component part (PSEC) 38, and frame number part (PFRAME) 39), and each of these parts consists of 8-bit data.

Track number part (TNO) 31, elapsed time minute component part (MIN) 33, second component part (SEC) 34,
The frame number part (FRAME) 35 is fixed to "00" in hexadecimal notation, and the zero part (ZERO) 36 is
Similar to the zero part (ZERO) 26 described above, "00" is added to all 8 bits.

The absolute time component part (PMIN) 37
Indicates that the point part (POINT) 32 is in hexadecimal notation.
In the case of "A0", it indicates the first song number or movement number, and the point part (POINT) 32 is displayed in hexadecimal notation.
In the case of "A1", it shows the first song number or movement number. When the point part (POINT) 32 is in hexadecimal notation and is "A2", the absolute time component part (PMIN)
An absolute time second component part (PSEC) 38 and an absolute time frame number part (PFRAME) 39 indicate the absolute time (PTIME) at which the lead-out area starts.
Furthermore, when the point part (POINT) 32 is represented by a 2-digit BCD, the absolute time minute component part (PMIN) 37, second component part (PSEC) 38, and frame number part (PFRAME) 39 are respectively , The address at which each song or movement indicated by the numerical value starts is expressed in absolute time (PTIME).

As described above, in the Q channel, although the format is slightly different between the program area and the lead-in area of the disc, time information represented by 24 bits is recorded in both. According to the CD standard, the sub-code of the Q channel of mode 1 shown in FIG. 5 contains 9 or more sub-code frames in any continuous 10 sub-code frames on the disc. As described above, the subcode frame is a continuous 98 frames in which the first two frames form one delimiter of the subcode having the synchronization pattern.

On the other hand, modes 2 to 5 other than mode 1
In the case of subcodes of other modes, it is specified that one or more of them may be present in 100 consecutive subcode frames. In addition, mode 2 and mode 3 are UPC /
EAN (Universal Product Code / European Article Num
ber) code, ISRC (International Standard Record)
ing Code) Used to record a code. Mode 4
Is used in CDV. Mode 5 is used in the lead-in of multi-session CD-EXTRA. Therefore, it is actually sufficient to consider the sub-codes of the Q channels of mode 1, mode 2 and mode 3, and the description of mode 4 and mode 5 is omitted below.

In one embodiment of the present invention, the reflectance is changed by irradiating the reflection film with a laser beam, and the frame sync is recorded. The frame sync in the CD format will be described with reference to FIG. The frame sync has a length of 24 bits (channel bits), and the inversion interval is 11T, 1.
It is 1T, and 2T is added after that. There may be a pattern A and a pattern B depending on how the two 11Ts correspond to the pits and lands. 11T on the front
The recording pattern corresponding to the pits P1 and P3 is the pattern A, and the recording pattern corresponding to the rear 11T is the pattern B. It should be noted that when the bit is "1", the edge on the front side of the bit cell is shown to coincide with the change in the pit and the land, but even if the center position of the bit cell of "1" coincides with this change. good.

The method of additional recording of the frame sync will be described more specifically with reference to FIG. First, the case of pattern A will be described. Normally, the pit P1 having a length of 11T is divided into two pits P4 (length 4T) and P5 (length 4T) and a land L1 having a length of 3T located therebetween. A pit P6 is formed corresponding to the pit P3. Then, a laser beam for additional recording is applied to the land L1 with diagonal lines between the two pits P4 and P5. As a result, the reflectance of the land L1 is lowered, and after recording, it is reproduced as one pit P7 in which two pits are combined. Koo Pit P7
Is 11T, and the original frame sync pattern (11T, 11T, 2T) is formed after additional recording.

The front side 11T is a land, and the rear side 11T.
Similarly, in the case of the pattern B in which T is the pit P2, the pit P2 has two pits P8 (length 4T) and P9,
The land is divided into lands L2 located therebetween. A laser beam for additional recording is applied to the land L2 with diagonal lines between the two pits P8 and P9. As a result, the reflectance of the land L2 is lowered, and after recording, it is reproduced as one pit P10 in which two pits are combined. The core pit P10 has a length of 11T, and the original frame sync pattern (11T, 11T, 2
T) is formed.

As described above, by additionally recording on the reflective film, it is possible to record a frame sync conforming to the standard. Therefore, a regular frame sync is not formed only by the concavo-convex pattern on the disk substrate.
Even if you try to manufacture a pirated copy by peeling, a part of the uneven pattern on the disc substrate is different from the regular frame sync. Cannot be detected. Usually, in the player, when the frame sync is missing and cannot be detected, interpolation processing is performed. However, if the frame sync cannot be detected for a certain period of time or more, the phase difference between the interpolated frame sync and the reproduction data becomes large, and normal reproduction cannot be performed. Therefore, actually, the number of interpolations is limited to a predetermined number. Thus, the pirated version of peeling is
Since it cannot be reproduced, it is possible to prevent the production of pirated copies.

When the method of recording by rotating the disc is used as the method of additional recording on the reflective film, as in the case of mastering, when the frame sync is recorded by the additional recording entirely in the program area of the disc, the recording is performed. Since it takes a long time, the frame sync is recorded by a method of additional recording on the reflective film in, for example, a part of the head portion of the program area. The area of this additional recording is not limited to the head portion, but is formed at a fixed position on the disc, for example. The length of the additional recording area is selected in consideration of the number of interpolations of the frame sync, as described above.

FIG. 9 shows an example of the configuration of a mastering device for producing the data recording medium according to the present invention.
The mastering device is, for example, an Ar ion laser, He-
A laser 51 which is a gas laser such as a Cd laser or a Kr ion laser or a semiconductor laser, an acousto-optical effect type or electro-optical type optical modulator 52 which modulates the laser beam emitted from the laser 51, and the optical modulator 52. It has an optical pickup 53 which is a recording means having an objective lens and the like for condensing the laser light which has passed through and irradiating the photoresist surface of a disk-shaped glass master 54 coated with a photoresist which is a photosensitive material.

The optical modulator 52, according to the recording signal,
The laser light from the laser 51 is modulated. Then, the mastering device transmits the modulated laser light to the glass master 5
By irradiating No. 4, a master in which data is recorded is created. In addition, the optical pickup 53 is used as the glass master 5.
A servo unit (not shown) is provided for controlling so as to keep a constant distance from the No. 4, tracking control, and controlling the rotational driving operation of the spindle motor 55. The glass master 54 is rotationally driven by a spindle motor 55.

The recording signal from the adder 73 is supplied to the optical modulator 52. Main digital data to be recorded is supplied from the input terminal 61. The main digital data has a CD-ROM data format, for example. From the input terminal 62, subcodes (referred to as normal subcodes) of channels P to W based on the current CD standard are supplied. Normal subcodes include not only mode 1 but also mode 2 and mode 3 subcodes.

The main digital data is CIRC (Cr
An oss Interleave Reed-Solomon Code) encoder 65 is provided and subjected to error correction coding processing and scrambling processing for adding error correction parity data and the like.
That is, 16 bits of one sample or one word are divided into upper 8 bits and lower 8 bits to be each a symbol, and error correction coding for adding parity data for error correction by CIRC in this symbol unit, for example. Processing and scramble processing are performed.

The normal sub-code from the input terminal 62 is converted by the sub-code encoder 66 into a sub-code having the above-mentioned sub-code frame format, and CI
The main data from the RC encoder 65 and the sub code are mixed by the adder 69. The output of the adder 69 is EF
It is supplied to the M modulator 72, and 8 according to the conversion table.
Bit symbols are converted to 14 channel bits of data.

Further, a frame sync is supplied from the input terminal 63. The frame sync is the switch circuit 6
7 is supplied to the input terminal a. Reference numeral 64 is a data generator that generates data at a stage before additional recording. That is, regarding the frame sync in a certain fixed area, as described above, (4T, 3T, 4T,
11T, 2T) or (11T, 4T, 3T, 4T, 2
T) data is generated. The two data are
It can be switched according to the recording data.

The switch circuit 67 includes a switching signal generator 70.
Controlled by a switching signal from. Switching signal generator 7
0 generates a switching signal based on an instruction signal from a controller (referred to as CPU in the drawing) 71 that controls the entire mastering device. As described above, the area to be additionally recorded is a fixed position on the disc.
Therefore, it is possible to control so that the input terminal b is selected in the frame in which the data from the data generator 64 is recorded and the input terminal a is selected in the other frames.

The frame sync or data from the output terminal c of the switch circuit 67 is supplied to one input terminal of the adder 73. The output of the EFM modulator 72 is supplied to the other input terminal of the adder 73. From the adder 73, a recording signal of the above frame format is generated. This recording signal is supplied to the optical modulator 52, and the photoresist on the glass master 54 is exposed by the modulated laser beam from the optical modulator 52. The glass master disk 54 thus recorded is developed and electroformed to form a metal master, then a mother disk is made from the metal master, and then a stamper is made from the mother disk. . An optical disc is produced by a method such as compression molding or injection molding using a stamper. This optical disc is the same as a normal CD, but as described above, the material of the reflective film is selected so that additional recording can be performed.

FIG. 10 shows an example of the structure of a recording / reproducing apparatus for performing additional recording on the optical disk produced by the mastering and stamping described above. In FIG. 10, reference numeral 81 indicates a disk produced in the mastering and stamping steps. Reference numeral 82
Is a spindle motor for rotationally driving the disk 81, and 83 is an optical pickup for reproducing signals recorded on the disk 81 and performing additional recording. The optical pickup 83 is a semiconductor laser that irradiates the disc 81 with laser light, an optical system such as an objective lens, and the disc 81.
The detector includes a detector for receiving the return light from, a focus and tracking mechanism, and the like. When recording and when not recording,
The laser power is switched. At the time of recording, a laser having a power required to cause a change in the reflectance of the reflective film is used, and at the time of non-recording, a laser having a power required to read the information recorded on the disk 81. Is used. Further, the optical pickup 83 is sent in the radial direction of the disk 81 by a thread mechanism (not shown).

An output signal from, for example, a 4-division detector of the optical pickup 83 is supplied to the RF section 84. The RF unit 84 generates a reproduction (RF) signal, a focus error signal, and a tracking error signal by calculating the output signal of each detector of the four-division detector. The reproduction signal is supplied to the input terminal d of the switch circuit 85. The focus error signal and the tracking error signal are supplied to the servo unit 86. The servo unit 86 controls the rotation operation of the spindle motor 82 based on the reproduction clock of the RF signal, the focus servo of the optical pickup 83,
Control the tracking servo.

A reproduction signal from one output terminal e of the switch circuit 85 is supplied to the sync detector 87. The sync detector 87 detects a frame sync added to the beginning of each frame. The reproduction signal from the other output terminal f of the switch circuit 85 is supplied to the data detection unit 88.
The data detection unit 88 collects data (4T, 3T, 4T, 11T, 2T) and (11T, 4T, 3T, 4T, 2T) recorded instead of the frame sync in the area of the fixed position on the optical disc 81. To detect. The frame sync detection signal from the sync detection unit 87 is supplied to the servo unit 86 and the data detection unit 88.

The main data output from the frame sync detector 87 is supplied to the EFM demodulator 89 and subjected to the EFM demodulation processing. The main digital data from the EFM demodulator 89 is taken out to the output terminal 90 as needed. The subcode data from the EFM demodulator 89 is supplied to the subcode decoder 91. The subcode decoder 91 decodes a normal subcode by processing such as CRC check and outputs the reproduced subcode to the output terminal 92.

Further, the reproduced subcode is a controller (CPU in the figure) for controlling the entire recording / reproducing apparatus.
And the servo unit 86.
This allows the controller 93 to know the current reading position and to access the desired position on the disc.

The switch circuit 85 is switched based on the switching signal from the area designating section 95. The area instruction unit 95 generates a switching signal based on an instruction signal from the controller 93 that controls the entire recording / reproducing apparatus. An instruction signal from the area instructing section 95 is supplied to the recording position determining section 94. The data detector 88 detects the recorded data instead of the frame sync, and the detection output is supplied to the recording position determination unit 94. The output of the data detector 88 indicates which of pattern A and B data is recorded.

The recording position determining unit 94 determines the position (location) at which additional recording is required within the additional recording area. That is, within the area on the disc created by mastering, a part of the predetermined data recorded instead of the frame synchronization signal is determined as the recording position, and the recording position is irradiated with the laser of the recording power. The recording operation is performed. Lands L1 or L2 with diagonal lines in FIG.
Is the recording position. From the recording position determination unit 94 to the recording circuit 9
A control signal for changing the laser power to the recording power is supplied to 6. In response to this control signal, the recording circuit 96 increases the laser power at a predetermined position to form a pit having a length of 11T, which is a connection of two pits. Further, the recording position determination unit 94 supplies a signal indicating the recording position to the servo unit 86.

FIG. 11 is a flow chart showing an example of a process for discriminating a legal disc from a pirated disc. In the first step S1, a disc is inserted into the playback device. In the next step S2, the reproducing device reproduces the additional recording area. Since the reproducing device normally reproduces the TOC information recorded in the lead-in area of the disc, if the additional recording area is not formed in the lead-in area, the additional recording area is reproduced after the reproduction of the TOC information. It

When the additional recording area is reproduced, it is determined in step S3 whether or not the frame sync is correctly read.
Is determined in. In the case of a regular disc, since the correct frame sync is recorded by the additional recording, the frame sync can be read. When it is determined that the reading of the frame sync has been correctly performed, the reproduction is permitted in step S4, and the reproduction of the disc becomes possible.

If it is determined in step S3 that the frame sync reading has not been performed correctly, a value of 1 is set in the interpolation count i in step S5. Then, in step S6, the frame sync is interpolated. In the next step S7, it is determined again whether or not the reading of the frame sync has been correctly performed. If it is determined that the frame sync has been read correctly, the process proceeds to step S4, and the disc can be reproduced.

If it is determined in step S7 that the frame sync could not be read correctly, the number of interpolations i is incremented by 1 (that is, incremented) in step S8. Then, in step S9, it is determined whether or not the number of interpolations i has reached n or more. The value of n is the number of times the frame sync can be interpolated, and is set in advance. If the number of interpolations i is less than n, the interpolation is possible. If the number of interpolations i is not n or more, the process returns to step S6 (frame sync interpolation process).

If, in step S9, the number of interpolations i
If it is determined that the number has reached n or more, the process proceeds to step S10, it is determined that the inserted disc is illegal, and the reproduction is prohibited or the reproduction operation is an error.
In this case, a message such as "Illegal disc." Is displayed on the display unit of the playback device.

The present invention is not limited to the above-described embodiment of the present invention and the like, and various modifications and applications can be made without departing from the gist of the present invention. For example, all the target areas for additional recording may be set as land areas (unrecorded areas), and the entire frame sync may be additionally recorded therein. Also, the pattern of the synchronization signal can be a pattern other than (11T, 11T, 2T) depending on the recording medium. Further, the additional recording area is not limited to the program area of the disc and may be provided in the lead-in area. Double-speed recording may be performed during additional recording.

The present invention can also be applied to, for example, a multi-session optical disc for recording data in the CD-DA format and data in the CD-ROM format, respectively. The information recorded on the optical disc includes audio data, video data, still image data, character data, computer graphic data,
Various data such as game software and computer programs are possible. Therefore, the present invention can be applied to, for example, DVD video and DVD-ROM. Furthermore, the present invention can be applied not only to a disk shape but also to a card-shaped data recording medium.

[0066]

As is apparent from the above description, according to the present invention, since the synchronizing signal is recorded by the recording method for the reflective film, the stamper is manufactured from the disc substrate from which the reflective film is peeled off, and the stamper is used. Even if you make a pirated copy,
The regular sync signal is not recorded and reproduction is impossible. As a result, it is possible to prevent pirated copies from spreading.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a conventional CD recording pattern and a CD structure.

FIG. 2 is a schematic diagram for explaining a disc manufacturing process to which the present invention is applied.

FIG. 3 is a schematic diagram illustrating a frame format of a CD.

FIG. 4 is a schematic diagram illustrating a subcode frame of a Q-channel subcode.

FIG. 5 is a schematic diagram showing a format of mode 1 for recording time information as a Q-channel subcode.

FIG. 6 is a schematic diagram for explaining the format of mode 1 in the TOC area.

FIG. 7 is a schematic diagram used to describe a frame sync to which the present invention can be applied.

FIG. 8 is a schematic diagram used to describe an example of a frame sync recording method according to an embodiment of the present invention.

FIG. 9 is a block diagram showing an example of a configuration of a mastering device according to an embodiment of the present invention.

FIG. 10 is a block diagram showing an example of a configuration of a recording / reproducing apparatus for additional recording that is an embodiment of the present invention.

FIG. 11 is a flowchart illustrating an example of disc discrimination processing.

[Explanation of symbols]

2 ... Reflective film, 51 ... Laser, 53 ... Optical pickup, 54 ... Glass master, 63 ... Normal frame sync input terminal, 64 ... Data generator, 8
1 ... Disc created by mastering

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Claims (9)

[Claims] 1. A data recording medium in which a concavo-convex pattern corresponding to recording information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered, wherein a synchronization signal used for reproducing the recording medium is recorded. A data recording medium, at least a part of which is recorded by the recording method for the reflective film. 2. The reflectivity of the reflective film before the irradiation of the laser beam and the reflectivity of the reflective film after the irradiation of the laser beam according to claim 1, wherein the synchronization signal is binary data. A data recording medium corresponding to "0" and "1" of the above synchronization signal. 3. The recording medium according to claim 1, wherein a synchronization signal recorded by the recording method for the reflective film is included in a predetermined area. 4. A data recording medium in which a concavo-convex pattern according to recording information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered, and a sync signal used for reproducing the recording medium. An area in which at least a part is recorded is an unrecorded area, or other data is recorded in the area, and the synchronization signal can be recorded in the area by the recording method for the reflective film. Data recording medium. 5. The reflection signal according to claim 4, wherein the synchronization signal is binary data, and the reflectance of the reflection film before the laser beam irradiation and the reflectance of the reflection film after the laser beam irradiation are A data recording medium corresponding to "0" and "1" of the above synchronization signal. 6. A recording method for a data recording medium, wherein a concavo-convex pattern according to recording information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered, wherein the recording method for the reflective film is performed. A data recording method for recording at least a part of a synchronization signal used for reproducing a medium. 7. A recording apparatus for a data recording medium, wherein a concavo-convex pattern according to recorded information is formed on a track, and a reflective film whose characteristics can be changed by laser irradiation is covered, by the recording method for the reflective film. A data recording device for recording at least a part of a synchronization signal used for reproducing a medium. 8. A synchronization signal used for reproducing a recording medium in a recording method for a data recording medium, wherein a concavo-convex pattern according to recording information is formed on a track and a reflective film whose characteristics can be changed by laser irradiation is covered. Data recording in which at least a part of the area is recorded as an unrecorded area or other data is recorded in the area and the synchronization signal can be recorded in the area by the recording method for the reflective film. Method. 9. A synchronization signal used for reproducing a recording medium in a recording device for a data recording medium, wherein a concavo-convex pattern according to recording information is formed on a track and a reflective film whose characteristics can be changed by laser irradiation is covered. The data in which at least a part of the area is recorded as an unrecorded area, or other data is recorded in the area, and the predetermined data can be recorded in the area by the recording method for the reflective film. Recording device.