JP2004127439A - Optical disk recording medium and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact disk which is difficult to be duplicated. <P>SOLUTION: An optical disk recording medium with digital audio data in a state in which the audio data is converted into an EFM (eight to fourteen modulation) signal after error correction processing of the audio data by CIRC (cross interleaved Reed-Solomon code) recorded thereon is configured to replace an EFM signal having 1-3 sectors with an EFM signal different from a primary EFM signal in a track to be protected. In such a case, the replaced EFM signal portion is detected as an error by the error correction processing of the CIRC on a reproducing device side. Since the error is caused by replacing the EFM signal itself, the error can not be coped with by the correction processing and is processed by interpolation with reference to surrounding signals. Accordingly, a tone quality is not degraded even in reproducing with audio equipment and even in reproducing with computer equipment using a CD-ROM drive, but it is impossible for the EFM signal to be duplicated by using the computer equipment. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical disk recording medium such as an audio compact disk and a method of manufacturing the same, and more particularly, to an optical disk recording medium and a method of manufacturing an optical disk recording medium that is considered to be copy-protected while maintaining sound quality.
[0002]
[Prior art]
CD-DA compact discs are widely and generally used as optical disc recording media that can be handled by audio equipment.
[0003]
This compact disk reads data by a CD-ROM drive of a computer device, and writes the read data to a CD-R disk (CD-RW disk) by a CD-R drive (CD-RW drive). It is possible to easily make a copy (clone) having the same digital contents as the compact disk to be used.
[0004]
As a technique for preventing such copy creation, as a prior art related to the invention of this application, a method called CDS (Cactus Data Shield) developed by Midbar Tech of Israel has been adopted by some companies. .
[0005]
In the CDS system, music playback software for computer equipment and compressed digital data for the music playback software are recorded in addition to the normal CD-DA digital audio data.
[0006]
When the CD-ROM drive attempts to reproduce the disc, the compressed digital data is automatically reproduced by music reproduction software instead of the CD-DA digital audio data.
[0007]
In addition, there is a method in which an error is generated in the CD-ROM drive on the reading side when an attempt is made to copy using the CD-ROM drive and the CD-R drive while the TOC portion is in an abnormal state.
[0008]
In addition, there is a technique of replacing the EFM signal with another signal, but another problem arises that the portion is clearly identifiable from the disk surface, and the optical pickup of the reproducing apparatus cannot track normally.
[0009]
Further, as prior art document information related to the invention of this application, there is another technology, such as the following Patent Document 1.
[0010]
[Patent Document 1]
Japanese Translation of International Patent Publication No. 11-507160 (page 2, Fig. 2)
[0011]
[Problems to be solved by the invention]
Discs that are copy-protected by the CDS method described above deviate from those specified in the Red Book that defines the standards for compact discs. Therefore, it cannot be officially called a “compact disc”.
[0012]
In addition, there is a problem in that reproduction cannot be performed in some car audio devices and portable CD players that use a CD-ROM drive originally used for computer equipment for the mechanical part.
[0013]
In addition, when reproduction is performed on a computer device, there is a problem that the sound quality is extremely poor because of the use of compressed data.
[0014]
According to the present invention, it is possible to suppress copying using a computer device using a CD-ROM drive while maintaining a state in which sound quality is not degraded during playback on an audio device or a computer device using a CD-ROM drive. The present invention relates to a possible optical disk recording medium and an optical disk recording medium manufacturing method.
[0015]
[Means for Solving the Problems]
The inventor of the present application has diligently studied the relationship between normal reproduction and copying of a compact disc, and has no effect on normal reproduction using not only audio equipment but also computer equipment. On the other hand, a new deterrent method has been found.
[0016]
That is, the present invention as a means for solving the above-mentioned problem is as described below. Note that as terms used in the present invention, CIRC is an abbreviation for Cross Interleaved Reed-solomon Code, and EFM is an abbreviation for Eight to Fourteen Modulation.
[0017]
(1) An invention according to claim 1 is an optical disc recording medium in which digital audio data is recorded in a state where it is converted into an EFM signal after being subjected to error correction processing by CIRC. An optical disk recording medium characterized in that EFM signals of up to three sectors are replaced with EFM signals different from original ones.
[0018]
The invention according to claim 3 is a method for manufacturing an optical disk recording medium in which digital audio data is error-corrected by the CIRC and then recorded in a state converted to an EFM signal. In a track to be formed, an EFM signal of one sector to three sectors is replaced with an EFM signal different from the original, a molding die is created, and an optical disk recording medium is created by the molding die. Optical disk recording medium manufacturing method.
[0019]
The replacement of the EFM signals of one to three sectors as described above may be performed at least one location per track in a track for which copying is to be suppressed, and may be performed at a plurality of locations per track.
[0020]
Note that a sector is a section of data, and on a compact disc, data is organized in sector units. This sector includes a header, synchronization information, user data, an error detection code, an error correction code, and control information, and may be called a block or a frame.
[0021]
According to these inventions, in mastering when manufacturing an optical disk recording medium for audio such as a compact disk, protection (copy protection) is performed in a state where digital audio data is subjected to error correction processing by CIRC and then converted to an EFM signal. In the track to be replaced, the EFM signals of one to three sectors are replaced with EFM signals different from the original ones, a molding die is created in that state, and an optical disk recording medium is created using the molding die.
[0022]
In the track in which the EFM signals of one to three sectors have been replaced in this way, the replaced EFM signal portion is detected as an error by the CIRC error correction on the reproducing apparatus side. Since this error is caused by replacing the EFM signal itself, it cannot be dealt with by correction, and is processed by interpolation with reference to surrounding signals. For this reason, the sound quality is not degraded by the reproduction by the audio device or the reproduction by the computer device using the CD-ROM drive.
[0023]
On the other hand, if an attempt is made to copy using a CD-ROM drive and a CD-R drive, an error occurs in reading by the CD-R drive in a track in which the EFM signal of one to three sectors has been replaced. That is, the error correction on the reading device side detects that the replaced EFM signal portion is erroneous. Since this error is due to the replacement of the EFM signal itself, it cannot be dealt with by correction, resulting in a fatal error and a failure to copy normally.
[0024]
In the present invention, since the original EFM signal is replaced with another EFM signal, it is not possible to identify which part is protected by observing the optical disk recording medium. Further, since the replaced part is also an EFM signal, no tracking problem occurs in the optical pickup of the reproducing apparatus.
[0025]
That is, an optical disk recording medium and an optical disk recording medium capable of suppressing copying using a computer device while maintaining a state in which sound quality is not degraded in reproduction by an audio device or by a computer device using a CD-ROM drive A manufacturing method can be realized.
[0026]
(2) The invention according to claim 2 is an optical disc recording medium in which digital audio data is error-corrected by the CIRC and then recorded in a state converted to an EFM signal. An optical disc recording medium characterized in that it is configured to include a portion where the interval between indexes provided in the inside is 1 sector to 3 sectors.
[0027]
The invention according to claim 4 is a method of manufacturing an optical disc recording medium in which digital audio data is error-corrected by the CIRC and then recorded in a state converted to an EFM signal. In a track to be formed, a molding die is created so as to include a portion where an interval between indexes provided in the track is 1 to 3 sectors, and an optical disc recording medium is created by the molding die. An optical disc recording medium manufacturing method characterized by the following.
[0028]
The above-described indexing of one sector to three sectors may be performed at least one location per track in a track where copying is to be suppressed, and may be performed at a plurality of locations per track.
[0029]
In the present invention, the “index” refers to a location within a track where a cue can be located, and a maximum of 99 indices can be given per track.
[0030]
According to these inventions, in a mastering process for manufacturing an optical disc recording medium for audio such as a compact disc, a portion of a track to be protected in which an interval between indexes provided in the track is 1 to 3 sectors. And a molding die is prepared in that state, and an optical disk recording medium is prepared using the molding die.
[0031]
In this case, since there is no problem with the digital audio data of the CD-DA, the sound quality is not deteriorated in the reproduction by the audio device or the reproduction by the computer device using the CD-ROM drive.
[0032]
When the index information has three or less sectors as described above, according to the inventors of the present application, the CD-R and CD-RW drives controlled by a common command called MMC (MultiMediaCommand) have found that the inventors of the present application have diligently confirmed. , Turned out to be unable to respond. That is, when a copy is made, an error occurs in a track including information of an index of three sectors or less.
[0033]
That is, when copying is performed using a CD-ROM drive and a CD-R drive, when writing is performed by a CD-R drive or a CD-RW drive on a track where index information of one to three sectors exists. An error occurs and it is impossible to make a copy in a normal state.
[0034]
In the present invention, since only the index information is in a specific state, it is not possible to identify which part is protected by observing the optical disk recording medium. Further, since no change is made to the EFM signal, no tracking problem occurs in the optical pickup of the reproducing apparatus.
[0035]
That is, an optical disk recording medium and an optical disk recording medium capable of suppressing copying using a computer device while maintaining a state in which sound quality is not degraded in reproduction by an audio device or by a computer device using a CD-ROM drive A manufacturing method can be realized.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail. In the embodiments described below, an audio compact disc on which CD-DA digital audio data is recorded will be described as a specific example of an optical disc recording medium.
[0037]
<First Embodiment>
FIG. 1 is a schematic view schematically showing a state in which a compact disc is molded and manufactured according to a first embodiment of the present invention.
[0038]
In FIG. 1, reference numeral 10a denotes an encoder which receives digital audio data of CD-DA, performs error correction processing of a recording system by a cross interleave read-solomon code (CIRC), and then performs EFM (Eight to Fourth Modulation). By converting the data into a signal, digital data for CD recording to be finally recorded on a compact disc is generated.
[0039]
Reference numeral 10b denotes an encoder of the same type as the above-described encoder 10a, but generates an EFM signal without a signal input. The encoder 10b only needs to generate an EFM signal having a value different from that of the encoder 10a.
[0040]
Reference numeral 20 denotes a control unit, which is a track to be protected (copy-protected) in a state where digital audio data is subjected to error correction processing by the CIRC and converted to an EFM signal at the time of mastering. Switching control is performed to replace the EFM signal with an EFM signal (an EFM signal from the encoder 10b) different from the original EFM signal (an EFM signal from the encoder 10a).
[0041]
Note that a sector is a section of data, and on a compact disc, data is organized in sector units. This sector includes a header, synchronization information, user data, an error detection code, an error correction code, and control information, and may be called a block or a frame.
[0042]
A switching unit 22 switches between an EFM signal from the encoder 10a and an EFM signal from the encoder 10b in a normal state based on the control of the control unit 20.
[0043]
Reference numeral 30 denotes a molding die making apparatus for producing a molding die based on the data (EFM signal) of the CD recording digital data switched by the switching section 22, and is a master for molding and manufacturing a compact disc. A molding die (stamper) 40 is formed. The molding die making device 30 includes a die making part 31 and an operation part 32.
[0044]
That is, as described above, when the stamper 40 is created by the molding die making apparatus 30 using the CD recording digital data (EFM signal) generated from the digital audio data by the encoder 10a, the control unit 20 sets the time from the encoder 10 During normal operation, the switching unit 22 transmits digital data from the encoder 10 a to the molding die producing device 30 in accordance with a control signal from the control unit 20.
[0045]
At a predetermined timing in a track for which copying is inhibited by the monitoring of the time data by the control unit 20, the switching unit 22 receives the control signal from the control unit 20 and changes the EFM signal from the encoder 10b by one to three sectors. Is output to the molding die forming apparatus 30.
[0046]
This means that the EFM signal from the encoder 10b is an EFM signal different from the original EFM signal generated from the digital audio data (the EFM signal from the encoder 10a).
[0047]
Since the music of one song is recorded on the compact disc as one track, the above-mentioned replacement of the EFM signal may be performed at any position of the track of the song for which copying is to be suppressed.
[0048]
Then, the control unit 20 monitors the time data from the encoder 10 and returns the switching unit 22 to the normal state when the replacement of the EFM signals of one to three sectors ends. In this way, the EFM signals from the encoders 10a and 10b are transmitted as digital data for CD recording to the molding die making apparatus 30.
[0049]
The replacement of the EFM signals of one to three sectors as described above may be performed at least one location per track in a track for which copying is to be suppressed, and may be performed at a plurality of locations per track.
[0050]
As described above, the switching state of the switching unit 22 is controlled by the control unit 20, and the EFM signal from the normal encoder 10a and the EFM signal from the encoder 10b are switched. A stamper 40 for creating a compact disk having the stamper is created.
[0051]
After the stamper 40 is formed as described above, the CD forming apparatus 50 forms and manufactures the compact disc 60 by using the above-described stamper 40 in the same procedure as usual.
[0052]
When the compact disc created according to the above-described embodiment is to be reproduced by a CD player of an audio device or a CD-ROM drive of a computer device (hereinafter, a reproducing device), the reproducing device performs EFM demodulation. The data for each bit is returned to 8 bits, and after error correction is performed by the reproduction-system CIRC, the data is DA-converted by the DA converter.
[0053]
At this time, in the track in which the EFM signals of 1 to 3 sectors have been replaced as described above, the replaced EFM signal portion is detected as an error by the CIRC error correction on the reproducing apparatus side. Since this error is caused by replacing the EFM signal itself, it cannot be dealt with by correction, and is processed by interpolation with reference to surrounding signals. As described above, even the portion where the EFM signal is replaced is processed by the interpolation of the CIRC, so that the sound quality is not deteriorated as usual in the reproduction by the audio device or the reproduction by the computer device using the CD-ROM drive. Is executed.
[0054]
On the other hand, if an attempt is made to copy using a CD-ROM drive and a CD-R drive, an error occurs in reading by the CD-R drive in a track in which the EFM signal of one to three sectors has been replaced. That is, the error correction on the reading device side detects that the replaced EFM signal portion is erroneous. Since this error is due to the replacement of the EFM signal itself, it cannot be dealt with by correction, resulting in a fatal error and a failure to copy normally. In this case, since digital data is copied, CIRC in the case of a CD player is not applied, and an error remains.
[0055]
In the first embodiment, the original EFM signal from the encoder 10a is replaced by another EFM signal from the same type of encoder 10b. By observing the compact disc, it is not possible to identify which part is protected to prevent copying. That is, the copy protection of the first embodiment cannot be released by hardware or software measures.
[0056]
Further, since the replaced portion is also an EFM signal, there is no problem of tracking and seeking in the optical pickup of the reproducing apparatus.
[0057]
In other words, according to the first embodiment, it is possible to effectively perform copying using a computer device while maintaining a state in which sound quality is not degraded during reproduction on an audio device and reproduction on a computer device using a CD-ROM drive. Deterrence becomes possible.
[0058]
<Second Embodiment>
FIG. 2 is a schematic view schematically showing a state in which a compact disk is molded and manufactured according to the second embodiment of the present invention.
[0059]
In FIG. 2, reference numeral 10 denotes an encoder, which receives digital audio data of CD-DA, performs error correction processing of a recording system by Cross Interleave Read-solomon Code (CIRC), and then performs EFM (Eight to Fourth Modulation). By converting the data into a signal, digital data for CD recording to be finally recorded on a compact disc is generated.
[0060]
Reference numeral 20 denotes a control unit which, in the process of generating an EFM signal after digital audio data is error-corrected by the CIRC at the time of mastering, in a track to be protected, an interval between indexes provided in the track is set. Control of index assignment is performed so as to include a portion of one to three sectors.
[0061]
In this embodiment, the “index” refers to a location within a track where a cue can be located, and a maximum of 99 indexes can be assigned to one track.
[0062]
That is, in the second embodiment, index assignment is performed such that the interval from one index to the next index is one to three sectors.
[0063]
Numeral 30 denotes a molding die making apparatus for producing a molding die based on the data (EFM signal) of the CD recording digital data from the encoder 10, which is a master for forming and manufacturing a compact disc. A mold (stamper) 40 is created. The molding die making device 30 includes a die making part 31 and an operation part 32.
[0064]
That is, as described above, when the stamper 40 is created by the molding die making apparatus 30 using the CD recording digital data (EFM signal) generated from the digital audio data by the encoder 10, the control unit 20 outputs the time from the encoder 10. The data is monitored, a normal index is normally assigned, and digital data from the encoder 10 is transmitted to the molding die forming apparatus 30 as it is.
[0065]
Also, the monitoring of the time data by the control unit 20 indicates that, at a predetermined timing in a track for which copying is to be suppressed, an index is assigned so that the interval from one index to the next index is one to three sectors. Is output to the molding die making device 30.
[0066]
Since one music piece is recorded on a compact disc as one track, the above index may be added at any position of the track of the music piece whose copying is to be suppressed.
[0067]
The above-described indexing of one sector to three sectors may be performed at least one location per track in a track where copying is to be suppressed, and may be performed at a plurality of locations per track.
[0068]
With the index given by the control unit 20 in this way, the molding die making apparatus 30 creates a stamper 40 for creating a compact disc having a copy inhibiting force.
[0069]
After the stamper 40 is formed as described above, the CD forming apparatus 50 forms and manufactures the compact disc 60 by using the above-described stamper 40 in the same procedure as usual.
[0070]
When the compact disc created according to the above-described embodiment is to be reproduced by a CD player of an audio device or a CD-ROM drive of a computer device (hereinafter, a reproducing device), the reproducing device performs EFM demodulation. The data for each bit is returned to 8 bits, and after error correction is performed by the reproduction-system CIRC, the data is DA-converted by the DA converter.
[0071]
In this case, since there is no problem as the CD-DA digital audio data, the sound quality is not degraded and reproduced as usual regardless of whether the data is reproduced by an audio device or a computer device using a CD-ROM drive. Be executed.
[0072]
On the other hand, if an attempt is made to make a copy using a CD-ROM drive and a CD-R drive, a general CD-R drive or CD-RW drive cannot cope with such a situation. An error occurs in a track including the following index information.
[0073]
That is, when the index information is one to three sectors as described above, according to the inventor of the present application, the inventors of the present application have eagerly confirmed that the CD-R and the CD-RW controlled by a common command called MMC (MultiMediaCommand). It turned out that the drive could not cope. More specifically, although it is possible to cope with continuous long data, if the continuous long data includes data of one to three sectors alone, the data of one to three sectors is regarded as continuous long data. It has the property of being mistaken. For this reason, the data portion of the first to third sectors is transformed into long random data different from the original.
[0074]
That is, when a copy is attempted using a CD-ROM drive and a CD-R drive (or a CD-RW drive), a CD-R drive or CD-R -An error occurs when performing writing with the RW drive, and it becomes impossible to create a copy in a normal state.
[0075]
In the second embodiment, since the EFM signal itself to be recorded on the compact disc is not changed, the recording surface of the compact disc has exactly the same irregularities as the normal track. Through observation, it is impossible to identify which part is protected to prevent copying. That is, the copy protection of the second embodiment cannot be canceled by hardware or software measures.
[0076]
Further, since the same EFM signal as usual is used, there is no problem of tracking and seeking in the optical pickup of the reproducing apparatus.
[0077]
That is, according to the second embodiment, it is possible to effectively perform copying using a computer device while maintaining a state in which sound quality is not degraded in reproduction on an audio device or on a computer device using a CD-ROM drive. Deterrence becomes possible.
[0078]
【The invention's effect】
As described above in detail with the embodiments, according to the invention described in this specification, the following effects can be obtained.
[0079]
(1) According to the first and third aspects of the present invention, in mastering when manufacturing an optical disk recording medium for audio such as a compact disk, digital audio data is converted into an EFM signal after error correction processing by CIRC. In the converted state, in the track to be protected (copy protected), the EFM signal of one to three sectors is replaced with an EFM signal different from the original, a molding die is created in that state, and the molding die is used. An optical disk recording medium is created using a mold.
[0080]
In the track in which the EFM signals of one to three sectors have been replaced in this way, the replaced EFM signal portion is detected as an error by the CIRC error correction on the reproducing apparatus side. Since this error is caused by replacing the EFM signal itself, it cannot be dealt with by correction, and is processed by interpolation with reference to surrounding signals. For this reason, the sound quality is not degraded by the reproduction by the audio device or the reproduction by the computer device using the CD-ROM drive.
[0081]
On the other hand, if an attempt is made to copy using a CD-ROM drive and a CD-R drive, an error occurs in reading by the CD-R drive in a track in which the EFM signal of one to three sectors has been replaced. That is, the error correction on the reading device side detects that the replaced EFM signal portion is erroneous. Since this error is due to the replacement of the EFM signal itself, it cannot be dealt with by correction, resulting in a fatal error and a failure to copy normally.
[0082]
That is, an optical disk recording medium and an optical disk recording medium capable of suppressing copying using a computer device while maintaining a state in which sound quality is not degraded in reproduction by an audio device or by a computer device using a CD-ROM drive A manufacturing method can be realized.
[0083]
(2) According to the second and fourth aspects of the present invention, an index provided in a track to be protected in mastering when manufacturing an optical disc recording medium for audio such as a compact disc. A molding die is prepared in such a state as to include a portion having an interval of 1 to 3 sectors, and an optical disk recording medium is prepared using the molding die.
[0084]
In this case, since there is no problem with the digital audio data of the CD-DA, the sound quality is not deteriorated in the reproduction by the audio device or the reproduction by the computer device using the CD-ROM drive.
[0085]
It has been found that when the index information is three sectors or less, the CD-R and CD-RW drives controlled by the common command cannot cope. That is, when a copy is made, an error occurs in a track including information of an index of three sectors or less.
[0086]
That is, when copying is performed using a CD-ROM drive and a CD-R drive, when writing is performed by a CD-R drive or a CD-RW drive on a track where index information of one to three sectors exists. An error occurs and it is impossible to make a copy in a normal state.
[0087]
That is, an optical disk recording medium and an optical disk recording medium capable of suppressing copying using a computer device while maintaining a state in which sound quality is not degraded in reproduction by an audio device or by a computer device using a CD-ROM drive A manufacturing method can be realized.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an overall state of a manufacturing apparatus for manufacturing an optical disk recording medium according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram showing an overall state of a manufacturing apparatus for manufacturing the optical disc recording medium according to the first embodiment of the present invention.
[Explanation of symbols]
10a Encoder
10b encoder
11 Data file
20 control unit
22 Switching unit
30 Mold making equipment
40 stamper
50 CD molding equipment
60 Compact Disc

Claims (4)

An optical disc recording medium in which digital audio data is error-corrected by the CIRC and then recorded in a state converted to an EFM signal,
In a track to be protected, an EFM signal of one to three sectors is replaced with an EFM signal different from the original one,
An optical disk recording medium characterized by the above-mentioned. An optical disc recording medium in which digital audio data is error-corrected by the CIRC and then recorded in a state converted to an EFM signal,
In a track to be protected, an interval between indices provided in the track includes a portion having one to three sectors.
An optical disk recording medium characterized by the above-mentioned. A method of manufacturing an optical disk recording medium in which digital audio data is error-corrected by a CIRC and then recorded in a state converted to an EFM signal,
At the time of mastering, a molding die is created in a state where EFM signals of one to three sectors are replaced with EFM signals different from the original in a track to be protected,
Creating an optical disk recording medium with the molding die,
An optical disc recording medium manufacturing method characterized by the above-mentioned. A method of manufacturing an optical disk recording medium in which digital audio data is error-corrected by a CIRC and then recorded in a state converted to an EFM signal,
At the time of mastering, in a track to be protected, a molding die is prepared so as to include a portion where an interval between indexes provided in the track is 1 to 3 sectors,
Creating an optical disk recording medium with the molding die,
An optical disc recording medium manufacturing method characterized by the above-mentioned.

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