JP2000040297A - Optical disk reproducing device, optical disk reproducing method, optical disk and optical disk recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk reproducing device which can inexpensively and surely prevent a pirate edition. SOLUTION: This reproducing device has a signal processing means including first decoding means 25, 26, 27 which decode first digital signals from regenerative signals, a memory means 33 which stores the first digital signals, a second decoding means which reads out the first digital signal stored in the storage means 33 and executes signal processing according to the first digital signals and obtains second digital signals from quantization signals, a quantization means 31 for obtaining quantization signals by subjecting the regenerative signals to A/D conversion and a cipher removing means 28 for removing the cipher applied to the information signals by using the second signal signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus for an optical disk such as a compact disk, an optical disk reproducing method for a compact disk player and the like, and an optical disk such as a compact disk and an optical disk recording apparatus (apparatus for producing an optical disk master).

[0002]

2. Description of the Related Art Conventionally, in a compact disc,
Audio signals and TOC (TableOf Contents)
(Index) and the like, an IFPI (International)
There was an area called the Federation of the Phonografic Industry code. In this code, a code indicating a maker, a manufacturing site, a disk number, and the like is stamped on the disk for the purpose of preventing piracy.

[0003]

The codes engraved on such a disk and indicating the manufacturer, the manufacturing site, the disk number, and the like can be visually recognized. For this reason, in a reproducing apparatus for reproducing a compact disc or the like,
These codes cannot be read. For this reason, there is a problem that the contents of these codes cannot be reflected in the operation control of the reproducing apparatus.

[0004] As a method of solving such a defect, for example, in the patent application of Japanese Patent Application No. 9-67843, which is unknown at the time of filing the present application, a code unique to a disk is recorded by changing the output of a recording laser. The method is described. By recording the code in the manner described in this patent application, the above-mentioned problem is solved, and the disc identification code that can be read by the playback device is changed to an area where a normal signal is recorded. Is superimposed and recorded. However, if a pirated disk is manufactured using the method described in this patent application as it is, the same disc identification code as that of a legitimate disk is recorded on the pirated disk. For this reason, there is a problem that such a method will be invalidated by being imitated eventually.

[0005] In any of the piracy prevention methods proposed so far, it is clear that pirate manufacturers will adopt the same method if the manufacturer of the piracy knows how to prevent the piracy. For this reason, there is a problem that any prevention method loses its effectiveness when the prevention method is known.

As a method of solving such a problem,
For example, in 1997 Patent Application No. 292071 (unknown at the time of filing of the present application), a key for decrypting a code is recorded on a disk, and when a key is decrypted, a detection algorithm recorded on a floppy disk or the like is used. A method for detecting this key is described. The method of this patent application has a feature that the method of recording a key can be changed one after another. As a result, even if the key recording method is decrypted by a pirated manufacturer, it is possible to change the key recording method one after another by distributing new floppies. Thus, pirated manufacturers will have to work one after another. By continuously changing the key recording method in this way, the production of a pirated copy requires a large amount of labor, and thus it is possible to effectively suppress the production of a pirated copy.

However, according to the method described in this patent application, a user must supply a disk together with a medium on which a detection algorithm such as a floppy disk is recorded, together with the disk. For this reason, there has been a problem that the cost is increased.

Accordingly, an object of the present invention is to provide an optical disk reproducing apparatus, an optical disk reproducing method, an optical disk, and an optical disk recording apparatus that can reliably and inexpensively prevent piracy.

[0009]

In the optical disk reproducing apparatus according to the first aspect of the present invention, an encryption process is performed in advance by forming a row of pits so as to form a spiral or a large number of concentric tracks. The optical disc on which the information signal is recorded is irradiated with light by an optical means, and the optical pickup that converts the light reflected or diffracted by the optical disc into an electric signal obtains a reproduction signal and reads the information signal recorded on the optical disc. In the optical disk reproducing apparatus described above, first decoding means for decoding a first digital signal from a reproduced signal, storage means for storing the first digital signal, and first digital signal stored in the storage means A signal is read, signal processing is performed according to the first digital signal, and a second digital signal is obtained from the quantized signal. Signal processing means including a second decoding means, a quantization means for obtaining a quantized signal by A / D-converting a reproduced signal, and a cipher for removing a cipher applied to an information signal using a second digital signal. And a removing means.

According to the first aspect of the present invention, the first decoding means decodes the first digital signal from the reproduced signal, stores the first digital signal in the storage means, and stores the first digital signal in the storage means. Read out the obtained first digital signal,
The signal processing means performs signal processing according to the first digital signal, and the quantizing means converts the reproduced signal into an A / A signal.
The quantized signal is obtained by D-conversion, and the cipher removing unit removes the cipher applied to the information signal using the second digital signal.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first aspect of the present invention, an information signal which has been subjected to encryption processing in advance by forming a row of pits so as to form a spiral or a large number of concentric tracks is recorded. An optical disc reproducing apparatus in which an optical disc is irradiated with light by optical means and an optical pickup for converting light reflected or diffracted by the optical disc into an electric signal to obtain a reproduction signal and read an information signal recorded on the optical disc. , First decoding means for decoding a first digital signal from a reproduced signal, storage means for storing the first digital signal, and reading the first digital signal stored in the storage means. 1 performs signal processing according to the digital signal,
A signal processing unit including a second decoding unit that obtains a second digital signal from the quantized signal; a quantization unit that obtains a quantized signal by performing A / D conversion on the reproduced signal; An optical disc reproducing apparatus comprising: a cipher removing means for removing a cipher applied to an information signal.

According to a second aspect of the present invention, in the optical disk reproducing apparatus according to the first aspect of the present invention, the signal processing means is constituted by a central processing means.

According to a third aspect of the present invention, in the optical disk reproducing apparatus according to the first aspect of the present invention, the reading of the information signal recorded on the optical disk is continued only when the second digital signal has a predetermined value. An optical disk reproducing apparatus including control means for controlling reading of an optical disk.

According to a fourth aspect of the present invention, in the optical disk reproducing apparatus according to the third aspect of the present invention, the operation of the control means is configured to be determined by a predetermined information signal recorded on the optical disk. .

According to a fifth, sixth, seventh and eighth aspect of the present invention, in the optical disc reproducing apparatus according to the first, second, third and fourth aspects of the present invention, the first decoding means comprises: A comparing means for converting into binary information by performing a magnitude comparison with a predetermined slice level; a converting means for collecting a predetermined number of outputs of the comparing means to create a bit pattern and converting the bit pattern into a decoded information signal An optical disc reproducing apparatus includes means for correcting errors in the output of the comparing means.

According to a ninth aspect of the present invention, a reproduction signal is obtained by irradiating light onto an optical disk on which an information signal encrypted in advance is recorded and converting the light reflected from the optical disk into an electric signal. In an optical disc reproducing method for reading an information signal recorded on a disc, a first decoding step of decoding a reproduced signal to obtain a first digital information signal, and an A / D for converting the reproduced signal into a quantized digital signal sequence
A conversion step; and a second decryption step of decrypting the encrypted information signal by performing signal processing on the digital signal sequence. The second decryption step converts the first digital information signal into a signal processing device. And a signal processing step performed by a signal processing device based on the first digital information signal read into the storage means.

According to a tenth aspect of the present invention, in the optical disk reproducing method of the ninth aspect of the present invention, there is provided an optical disk reproducing method comprising the step of determining whether to continue the optical disk reproduction in accordance with the output of the second decoding step. It is.

According to an eleventh aspect of the present invention, there is provided an optical disc in which a first digital information signal in which a plurality of pits forming a track are encrypted in advance is recorded.
A second digital information signal, which is a decryption code for decrypting, is superimposed and recorded on a pit on which the first digital information is recorded, and a decoding procedure for further decrypting the second digital information signal Is an optical disc recorded as a part of the first digital information signal.

According to a twelfth aspect of the present invention, in the optical disc of the eleventh aspect of the present invention, the first digital information signal has a length and a position of a plurality of pits on the optical disc in units of an integral multiple of a predetermined length. This is an optical disk recorded by being modulated.

According to a thirteenth aspect of the present invention, there is provided an optical disk recording apparatus for recording an information signal by irradiating a laser beam so as to focus on a medium, and modulating the laser beam to generate a first information signal on the medium. A first recording unit for recording, and a second recording unit for recording a second information signal on a medium by a method different from the first information signal, wherein the first information signal is based on a key information signal. The second recording means is configured to record the first information signal encrypted by the encryption means, and in particular, to decrypt the second information signal. This is an optical disk recording device that records a procedure as a first information signal.

[Specific Example of Embodiment of the Invention] First, FIG.
An optical disk (compact disk) master creating apparatus according to a specific example of the embodiment of the present invention will be described with reference to FIG. The optical disc master 1 is rotationally driven by a spindle motor 2. The rotation of the spindle motor 2 is controlled by a spindle servo circuit 3.

In practice, an FG signal generator (not shown) provided at the bottom of the spindle motor 2 (generates a frequency signal corresponding to the rotation of the motor 2) raises a signal level at every predetermined rotation angle of the motor 2. The rising frequency signal FG is output, and the frequency signal FG is supplied to the spindle servo circuit 3. The spindle servo circuit 3 generates a servo signal SV such that the frequency of the frequency signal FG becomes a predetermined frequency.
Is supplied to the spindle motor 2 to rotate the motor 2. Thus, the master disc 1 is rotationally driven at a predetermined rotation speed.

The recording laser light source 4 emits a laser beam (laser beam) L 1 to the optical modulator 5. The recording laser light source 4 is constituted by, for example, a gas laser or the like. The light modulator 5 and the light modulator 6 are configured by an electroacoustic optical element or the like. The optical modulator 5 power-modulates the laser beam L1 incident from the recording laser light source 4 according to a key information signal KY2 supplied from a key information generation circuit (the configuration of which will be described later) 13. That is, the optical modulator 5
When the key information signal KY2 is at level 1, the laser beam L2 is not attenuated without attenuating the laser beam L1.
When the key information signal KY2 is at level 0, the laser beam L1 is attenuated by a predetermined output and emitted as a weak laser beam L2.

As described above, in the optical modulator 5, the laser beam L2 whose output value is modulated by the key information signal KY2
Is further subjected to on / off control by the optical modulator 6. That is, the laser modulator L2 is turned on / off by the optical modulator 6 in accordance with an EFM (Eight to Fourteen Modulation) signal S3 supplied from the modulation circuit 18, and is emitted as a laser beam L3.

The mirror 7 bends the optical path of the laser beam L3 emitted from the optical modulator 6 by 90 ° and emits it toward the master disk 1. The objective lens 8 is a mirror 1
The reflected laser beam L3 from 0 is focused on the recording surface of the master disc 2. The mirror 10 and the objective lens 11
A sled mechanism (not shown) moves sequentially in the radial direction in synchronization with the rotation of the master disc 1.

In this way, the converging position of the laser beam L3 is sequentially shifted, for example, from the inner circumference to the outer circumference of the optical disc master 1, thereby forming a spiral track on the disc master 1. can do. Then, pits are sequentially formed on this track in correspondence with both the EFM signal S3 and the key information signal KY2.
The track may be composed of a large number of concentric circles.

On the other hand, audio data D1 recorded on the master disc 1 is a digital audio table recorder 9
Is supplied to the encryption circuit 10. The encryption circuit 10
Based on the key information signal KY1 obtained from the key information generation circuit 13, the audio data D1 is subjected to encryption processing using a DES code. DES in the DES code is Da
ta Encryption Standard (Data Encryption Standard), a widely used encryption method.

The signal S 1 encrypted by the encryption circuit 10 is supplied to one input terminal of the data selector 12. The key information detection program SC from the key information detection program generation circuit 11 is supplied to the other input terminal of the data selector 12. The output signal S1 of the encryption circuit 10 is selected by a system controller (not shown) in an area for recording normal user data, and the key information detection program SC is selected in an area of a predetermined track number in the lead-out area. And the data selector 14
Is switched, and the data signal S2 is output from the output terminal thereof and supplied to the modulation circuit 18.

The modulation circuit 18 generates an EFM signal S3 by performing data processing specified for an optical disk (compact disk) based on the data output from the data selector 12. That is, the modulation circuit 18 generates an EFM signal S3 by adding an erroneous correction code to the encrypted audio data S1 or the key information detection program SC, performing an interleave process, and further performing EFM modulation. The modulation circuit 18
TO supplied from sub-code generator (not shown)
Subcode data including C (Table Of Contents) (table of contents) information is inserted into the subcode area of the EFM signal S3. The EFM signal S3 thus completed is
The light is supplied to the optical modulator 6.

When the EFM modulated signal S3 is sent to the optical modulator 6, the laser beam obtained from the recording laser light source 7 is turned on / off to expose the master disc 1 to light. That is, when the EFM modulation signal S3 is at level 1, pits are recorded on the master disc 2, and when it is at level 0, nothing is recorded. Digital audio data is recorded on the master disc 2 by modulating the lengths and positions of the plurality of pits on the master disc 2 in units of an integral multiple of a predetermined length. Also, the key information signal KY2
Therefore, for example, in a portion where the key information signal KY2 is at level 1, the key information signal KY2 is recorded as a pit having a slightly larger width, and the key information signal KY2 is recorded.
Conversely, when Y2 is at level 1, the key information signal KY2 is recorded as a narrower pit.

As described above, the EFM signal S3 is recorded on the master disc 1 as "the presence or absence of a pit", and the key information signal KY2 is recorded as a change in the pit width.
Is recorded. That is, the key information signal KY2 and the EFM signal S
3 are recorded on the master disc 1 as pits. The change in the laser output due to the key information signal KY2 is set to a sufficiently small level so as not to impair the normal information recorded by the EFM signal S3.

Next, the key information generation circuit 13 will be described. The key information generation circuit 13 includes, for example, a random number generation circuit 14 and a serial conversion circuit 15 to which the random number signal is supplied. A start pulse ST is supplied to an input terminal 16 of the random number generation circuit 14 from a system controller (not shown) every time a new disc is cut.

The random number generation circuit 14 has an LFSR (Linear Fe
It is composed of a read-only memory such as an edback Shift Register, and outputs a different key information signal (key information data) KY1 every time the start pulse ST is supplied. In the example described here, the DES described above is used as an encryption method.
The sign was adopted. Since the length of the key information is determined to be 54 bits in the DES code, the random number generation circuit 14 outputs a different 54-bit key information signal KY1 every time a new disc is cut.

The key information signal KY1 is supplied to an encryption circuit 10 and used to encrypt the audio data D1 from the digital audio tape recorder 9.

The key information signal KY1 from the random number generation circuit 14
Is supplied to the serial conversion circuit 15. The serial conversion circuit 15 is configured by a parallel-serial conversion circuit or the like,
A 54-bit key information signal KY1 is sequentially read one bit at a time from the most significant bit to the least significant bit by a clock signal CK supplied to the input terminal 17 from a clock generator (not shown), so that a one-bit unit is read. Output as a key information signal KY2.

With the above configuration, the key information generation circuit 13 generates different key information signals KY1 and KY2 every time cutting is performed, and supplies the generated key information signals to the encryption circuit 10 and the optical modulator 5.

The signal obtained in this manner is transmitted to the optical modulator 5
Exposure is performed on the master disc 2 according to steps 6 and 6. Further, after developing the master disk 2, an electroforming process is performed to create a mother disk, and a stamper is created from the mother disk. Further, an optical disk (compact disk) 20 (see FIG. 2) is manufactured from the stamper in the same manner as in a normal compact disk manufacturing process.

For example, a pirated vendor obtains the optical disk 20 thus prepared, and
If an attempt is made to create a pirated copy by binarizing the reproduced signal obtained from 0 and sending it again to the cutting machine, the key information signal KY2 is not recorded in the pirated copy. As described below, a pirated disk on which the key information signal KY2 is not recorded cannot be reproduced.
Piracy can be prevented by binarizing the reproduction signal from the optical disk 20 and sending the binarized signal to the cutting machine.

Next, referring to FIG. 2, the signal from the digital audio tape recorder 9 is encrypted and recorded.
A reproducing apparatus for reproducing an optical disk (compact disk) 20 on which key information for decrypting the code is superimposed and recorded as a pit width will be described.

In the optical disk reproducing apparatus of FIG. 2, the entire system is controlled by a system controller 24. An optical disk (compact disk) 20 is driven to rotate by a spindle motor 21. The spindle motor 21 supplies a frequency signal from a frequency generator (not shown) that generates a frequency signal corresponding to the rotation to a servo circuit 23, and the servo signal from the servo circuit 23 is supplied to the spindle motor 21. Rotation is controlled. The optical pickup 22 is provided on the optical disc 20.
The optical disc 20 is irradiated with the convergent light by optical means.
The information signal recorded on the optical disc is read by converting the light reflected or diffracted by the photodetector into an electric signal.

The optical pickup 22 includes a servo circuit 23
And a servo circuit 23 supplies a focus servo signal and a tracking servo signal to the optical pickup 22, and applies a focus servo and a tracking servo to the optical pickup 22. The servo circuit 23 is controlled by a system controller 24. The reproduced RF signal generated by the optical pickup 22 is converted to a binarization circuit 25.
And an A / D converter (A / D converter) 31.

The binarizing circuit 25 includes the optical pickup 22
Binarization of the reproduction RF signal supplied from the CPU (by comparing the magnitude of the reproduction RF signal with a predetermined slice level,
Is converted to value information) to generate a binary signal BD. This binarized signal BD is supplied to the EFM demodulation circuit 26. The EFM demodulation circuit 26 performs EF of the binarized signal BD.
M demodulation (demodulation of collecting a predetermined number of outputs of the binarization circuit 25 to create a bit pattern and converting the bit pattern into a decoded information signal) is performed to generate an 8-bit unit signal. The generated 8-bit signal is an error (error)
The signal is supplied to a correction circuit {ECC (Error Correcting Code) (error correction code) decoding circuit # 27, where the error is corrected.

The error correction circuit 27 is based on the ECC added in the encoding at the time of recording, and the EFM demodulation circuit 2
6 corrects the error in the output. Such an error is caused, for example, by a defect on the optical disc 20 or the like.

On the other hand, the A / D converter 31 digitizes (quantizes) the reproduced RF signal to obtain a digital reproduced signal DRF.
To a DSP (Digital Signal Processor) (central processing unit) 32. The DSP 32 performs signal processing on the digital reproduction signal DRF in accordance with a program stored in the memory 33 to obtain key data KY, as described later in the flowchart of FIG.

The system controller 24 is configured to perform the processing shown in the flowchart of FIG. 3 every time a new optical disk 20 is inserted, prior to actual reproduction.

In the process of the system controller 24 shown in FIG. 3, first, in step ST-1, the system controller 24 gives an instruction to each part of the system including the servo circuit 23 to focus the laser beam emitted from the optical pickup 22. The position is designated as a predetermined track in the lead-out area on the optical disc 20, and the track is accessed. Next, as step ST-2, an operation of reading and decoding the key information detection program recorded on the track is performed. Here, at the stage of reading and decrypting the key information detection program, since the key information signal has not been detected, the encryption cannot be decrypted. Therefore, it is assumed that only the key information detection program read and decrypted in this way has not been subjected to encryption processing.

In step ST-3, the system controller 24 instructs the memory 33 to store the read and decrypted key information detection program.

In a specific example of the present embodiment, the key information signal KY is superimposed and recorded as a pit width. It is known that when superposition recording is performed by modulating the pit width in this manner, information recorded as a change in the pit width is observed as a change in the envelope in the reproduced signal. Then, it is read from the optical disc 20 and
The key information detection program decrypted and stored in the memory 33 is a program describing signal processing for detecting an envelope change of a reproduced signal.

As described above, step ST-
By the processes from 1 to ST3, the inside of the memory 33 is
A signal processing method for obtaining the key information signal KY superimposed and recorded on the optical disc 20 from the reproduced digitized RF signal DRF is written as a program. Next, in step ST-4, the system controller 24
Instruct P32 to execute the key information detection program stored in the memory 33.

Accordingly, the DSP 32 performs appropriate signal processing on the digitized RF signal DRF in accordance with the program read from the memory 33, and decodes the key information signal (a release code signal for decrypting the encryption) KY. Then, the data is supplied to the encryption processing circuit 28. In addition, DSP32
Performs appropriate signal processing on the digitized RF signal DRF in accordance with the program obtained from the memory 33, determines whether or not the key information signal KY has been correctly recorded, and sets the determination result as a valid flag EF as the system controller 24. To supply.

The optical disk 20 is legal (not pirated)
If it is a disc, the decrypted key information signal KY
Is the key information signal KY1 or KY used for recording.
Should be identical to 2. So, in such a case,
The encryption processing circuit 28 can obtain a key information signal KY necessary for decryption. Therefore, by supplying the output of the encryption processing circuit 28 to the D / A converter 29, the output of the D / A converter 29 becomes an audio signal (music signal), and the user can enjoy the music recorded on the optical disc 20. Becomes possible.

Therefore, the system controller 24 finally checks in step ST-5 whether the key information signal KY recorded on the optical disk 20 has been correctly obtained by checking the valid flag EF. If it is determined that the key information is correctly obtained (OK), the process proceeds to step ST-6, where the optical disk 20 is reproduced using the obtained key information, and the reproduction of the performance is continued.

The key data K is determined by the valid flag EF.
If it is determined that Y is not recorded (NG),
The process proceeds to step ST-7 and the system controller 24
Since there is a possibility that the optical disk 20 is a pirated version, the reproducing operation of the disk reproducing device is stopped, and the reproduction of further performance is stopped.

As described above, the optical disk reproducing apparatus according to the specific example of the embodiment of the present invention is configured to obtain a method for decoding the key information signal KY from data recorded on the optical disk 20. Therefore, effective countermeasures against piracy can be performed without requiring an external device such as a floppy disk. Also, the key information signal KY
It is also possible to change the recording method one after another, and it is possible to implement a truly effective countermeasure against piracy.

For example, in the case of a pirated disk produced by a method in which the optical disk of the specific example of the embodiment of the present invention is reproduced once, the obtained reproduction signal is binarized, and then sent to the cutting machine again, the width of the pit is originally The key information recorded as is missing. Therefore, even if the pirated disk is reproduced by the optical disk reproducing apparatus according to the embodiment of the present invention as shown in FIG. 2, a correct key information signal KY cannot be obtained. Further, since the output of the valid flag EF cannot be obtained, the user cannot enjoy music from such a pirated disk.

As described above, according to the optical disk and the optical disk reproducing apparatus of the specific example of the embodiment of the present invention, the value of the pirated disk can be significantly reduced, and as a result, the spread of the pirated disk is hindered. It becomes possible.

In the specific example of the above-described embodiment, the key information detection program has been described as not being subjected to encryption processing. However, the present invention is not limited to this. It is also possible to convert. In this case, it becomes more difficult to create a pirate board,
The effect of increasing the degree of safety is expected.

Further, in the specific example of the above-described embodiment, an example in which the two signal processing devices of the system controller 24 and the DSP 32 are used has been described. However, the present invention is not limited to this. It is of course possible to have functions. In this case, the system controller 24 is replaced by the DSP 32, and one signal processing device can control the entire playback device.

[0059]

According to the first aspect of the present invention, an information signal which has been subjected to encryption processing in advance by forming a row of pits so as to form a spiral or a large number of concentric tracks is recorded. An optical disc reproducing apparatus in which an optical disc is irradiated with light by optical means and an optical pickup for converting light reflected or diffracted by the optical disc into an electric signal to obtain a reproduction signal and read an information signal recorded on the optical disc. , First decoding means for decoding a first digital signal from a reproduced signal, storage means for storing the first digital signal, and reading the first digital signal stored in the storage means. 1 performs signal processing according to the digital signal,
A signal processing unit including a second decoding unit that obtains a second digital signal from the quantized signal; a quantization unit that obtains a quantized signal by performing A / D conversion on the reproduced signal; Therefore, an optical disk reproducing apparatus having the following effects can be obtained.

According to the first aspect of the present invention, signal processing means for detecting an identification code (second digital signal) for preventing piracy is mounted, and the operation of the signal processing means is read from the optical disk being reproduced. As a result, the identification code (second digital signal) can be determined using various methods without the need for an external device such as a floppy disk. Detection can be performed. Therefore, it is possible to reproduce the optical disk on which the identification code is recorded in a new system one after another, and it is possible to prevent the generation of a pirated disk by making the creation of a pirated optical disk extremely difficult. . Furthermore, even when the key information hiding method for preventing a pirated disk is changed in various ways, there is no need to add another medium such as a floppy disk, and the function for preventing pirated disks is effective at a low cost. It is possible to manufacture discs that have been burned.

According to the third invention, in the optical disk reproducing apparatus of the first invention, reading of the information signal recorded on the optical disk is continued only when the second digital signal has a predetermined value. Therefore, the control means for controlling reading of the optical disk is included, so that the function of preventing the pirated disk, which is the effect of the first invention, can be further enhanced.

According to the ninth aspect of the present invention, a reproduced signal is obtained by irradiating an optical disk on which an information signal encrypted in advance is recorded with light and converting the light reflected from the optical disk into an electric signal. In an optical disc reproducing method for reading an information signal recorded on an optical disc, a first decoding step of decoding a reproduced signal to obtain a first digital information signal, and converting the reproduced signal into a quantized digital signal sequence / D conversion step, and a second decoding step of decoding the encrypted information signal by performing signal processing on the digital signal sequence. The second decoding step includes a first decoding step.
A writing step of writing the digital information signal into the storage means in the signal processing device;
And a signal processing step performed by the signal processing device based on the digital information signal described above. Therefore, an optical disk reproducing method having the following effects can be obtained.

According to the ninth aspect of the present invention, the program of the signal processing means for detecting the piracy prevention identification code (second digital signal) is determined according to the digital signal read from the optical disk being reproduced. Thus, it is possible to obtain an optical disk reproducing method which operates effectively without the need for an external device such as a floppy disk and is provided with a countermeasure against piracy.

According to the tenth aspect of the present invention, in the optical disk reproducing method according to the ninth aspect of the present invention, a determination step for determining whether or not to continue the optical disk reproduction in accordance with the output of the second decoding step is included. Thus, it is possible to obtain an optical disk reproducing method capable of enhancing the countermeasures against piracy, which is an effect of the ninth invention.

According to the eleventh aspect of the present invention, there is provided an optical disk in which a plurality of pits forming a track are recorded with a first digital information signal in which encryption processing has been performed in advance. Is recorded in a pit in which a second digital information signal, which is a decryption code for decrypting, is superimposed and recorded, and a decryption procedure for decrypting the second digital information signal is performed by the first digital information signal. Since the information is recorded as a part of the information signal, an optical disk having the following effects can be obtained.

According to the eleventh aspect of the present invention, even when the method of hiding the key information for preventing a pirated disk is changed in various ways, it is not necessary to add another medium such as a floppy disk, thereby reducing the cost. Thus, an optical disk having an effective pirated disk prevention function can be manufactured. In addition, there is an effect that the general consumer can reproduce the optical disk of the present invention without performing a complicated operation such as mounting the floppy disk first.

According to the thirteenth aspect of the present invention, in an optical disk recording apparatus for recording an information signal by irradiating a laser beam so as to focus on a medium, the first information is recorded on the medium by modulating the laser beam. A first recording unit for recording a signal; and a second recording unit for recording a second information signal on a medium by a method different from the first information signal.
The second recording means is configured to record the first information signal encrypted by the encryption means, and in particular, to encrypt the information signal based on the key information signal. Since the decoding procedure for decoding this information signal is recorded as the first information signal, it is possible to obtain an optical disc recording apparatus having the following effects.

According to the thirteenth aspect of the present invention, an optical disk recording apparatus capable of manufacturing an optical disk having an effective pirated disk prevention function at a low cost because no additional medium such as a floppy disk is required. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an optical disk master exposure apparatus for exposing an optical disk master according to a specific example of an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an optical disc reproducing device according to a specific example of the embodiment of the present invention;

FIG. 3 is a flowchart illustrating an operation of a system controller of the optical disc reproducing apparatus according to the specific example of the embodiment of the present invention;

[Explanation of symbols]

1 master disk, 2 spindle motor, 3 spindle servo circuit, 4 laser light source for recording, 5 and 6 optical modulator, 7 mirror, 8 objective lens, 9 digital audio tape recorder, 10 encryption circuit, 11 generation of key information detection program Circuit, 12 data selector, 13
Key information generation circuit, 14 random number generation circuit, 15 serial conversion circuit, 18 modulation circuit, 20 optical disk, 21
Spindle motor, 22 optical pickup, 23
Servo circuit, 24 system controller, 25 2
Value conversion circuit, 26 EFM demodulation circuit, 27 error correction circuit, 28 encryption processing circuit, 29 D / A converter, 31
A / D converter, 32 DSP, 33 memory.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 9/10 H04L 9/00 621A F term (Reference) 5D044 BC03 BC04 CC05 CC06 DE17 DE34 DE47 DE49 DE52 DE68 FG06 GK11 GK17 HH15 5D090 AA01 BB01 BB02 CC01 CC04 EE14 FF43 5D121 BB00 JJ05 5K013 BA02 EA02 FA05

Claims (13)

[Claims] 1. An optical system in which light is recorded on an optical disk on which an information signal pre-encrypted is formed by forming a row of pits so as to form a spiral or a large number of concentric tracks. An optical disc reproducing apparatus that irradiates and obtains a reproduction signal by an optical pickup that converts the light reflected or diffracted by the optical disc into an electric signal to read the information signal recorded on the optical disc, First decoding means for decoding a first digital signal from a first digital signal; storage means for storing the first digital signal; reading out the first digital signal stored in the storage means; A signal including second decoding means for performing signal processing according to the signal and obtaining a second digital signal from the quantized signal. Signal processing means; A / D conversion of the reproduced signal to obtain a quantized signal; and Cryptographic removal means for removing a code applied to the information signal using the second digital signal. An optical disc reproducing apparatus comprising: 2. The optical disk reproducing apparatus according to claim 1, wherein said signal processing means comprises a central processing means. 3. The optical disc reproducing apparatus according to claim 1, wherein the reading of the information signal recorded on the optical disc is continued only when the second digital signal has a predetermined value. An optical disc reproducing apparatus including a control unit for controlling reading of an optical disc. 4. The optical disk reproducing apparatus according to claim 3, wherein the operation of the control means is configured to be determined by a predetermined information signal recorded on the optical disk. . 5. The optical disc reproducing apparatus according to claim 1, wherein the first decoding unit compares the reproduced signal with a predetermined slice level to convert the reproduced signal into binary information. A conversion means for collecting a predetermined number of outputs of the comparison means to create a bit pattern and converting the bit pattern into a decoded information signal; and an error correction means for correcting an error in the output of the comparison means. An optical disk reproducing apparatus characterized in that it is performed. 6. The optical disk reproducing apparatus according to claim 2, wherein the first decoding means compares the reproduced signal with a predetermined slice level to convert the reproduced signal into binary information. A conversion means for collecting a predetermined number of outputs of the comparison means to create a bit pattern and converting the bit pattern into a decoded information signal; and an error correction means for correcting an error in the output of the comparison means. An optical disk reproducing apparatus characterized in that it is performed. 7. The optical disc reproducing apparatus according to claim 3, wherein the first decoding means compares the reproduced signal with a predetermined slice level to convert the reproduced signal into binary information. A conversion means for collecting a predetermined number of outputs of the comparison means to create a bit pattern and converting the bit pattern into a decoded information signal; and an error correction means for correcting an error in the output of the comparison means. An optical disk reproducing apparatus characterized in that it is performed. 8. The optical disc reproducing apparatus according to claim 4, wherein the first decoding means compares the reproduced signal with a predetermined slice level to convert the reproduced signal into binary information. A conversion means for collecting a predetermined number of outputs of the comparison means to create a bit pattern and converting the bit pattern into a decoded information signal; and an error correction means for correcting an error in the output of the comparison means. An optical disk reproducing apparatus characterized in that it is performed. 9. A reproduction signal is obtained by irradiating light onto an optical disk on which an information signal previously encrypted is recorded, and converting the light reflected from the optical disk into an electric signal, thereby obtaining a reproduction signal. An optical disc reproducing method for reading an reproduced information signal, a first decoding step of decoding the reproduced signal to obtain a first digital information signal, and an A / D conversion of converting the reproduced signal into a quantized digital signal sequence And a second decrypting step of decrypting the encrypted information signal by performing signal processing on the digital signal sequence. The second decrypting step includes converting the first digital information signal A writing step for writing to storage means in the signal processing device, and the signal processing device based on the first digital information signal read into the storage means Optical disc reproducing method characterized in that is constituted by the steps of signal processing performed. 10. The optical disk reproducing method according to claim 9, further comprising a determining step of determining whether to continue reproducing the optical disk in accordance with an output of the second decoding step. Playback method. 11. An optical disc in which a first digital information signal in which a plurality of pits forming a track have been subjected to encryption processing in advance is recorded, wherein a pit in which the first digital information is recorded is provided. A second digital information signal, which is a decryption code for decrypting the encryption, is superimposed and recorded, and a decryption procedure for decrypting the second digital information signal is performed by the first digital information signal. An optical disc characterized by being recorded as a part. 12. The optical disc according to claim 11, wherein the first digital information signal is modulated such that lengths and positions of a plurality of pits on the optical disc are integer multiples of a predetermined length. An optical disc characterized by being recorded by the above method. 13. An optical disk recording apparatus for recording an information signal by irradiating a laser beam so as to focus on a medium, wherein a first information signal is recorded on the medium by modulating the laser beam. 1 recording means, and a second recording means for recording a second information signal on the medium by a method different from the first information signal, wherein the first recording means comprises: An encryption unit that encrypts the information signal based on the key information signal, wherein the second recording unit is configured to record the first information signal encrypted by the encryption unit, An optical disc recording apparatus, wherein a decoding procedure for decoding the second information signal is recorded as the first information signal.