JP4051576B2 - Disc production apparatus, signal processing circuit, disc production method, signal processing method, disc, optical disc playback device, demodulation circuit, optical disc playback method and demodulation method - Google Patents

Description

  The present invention relates to a disc production device, a signal processing circuit, a disc production method, a signal processing method, a disc, an optical disc reproduction device, a demodulation circuit, an optical disc reproduction method, and a demodulation method, for example, an optical disc for recording audio data, and the recording device It can be applied to a playback device. In the present invention, pits and the like are displaced in the inner and outer circumferential directions of the optical disk, and sub data such as key data is recorded, and a displacement related to the sub data is created by a binary number sequence, thereby generating a pit sequence and the like. It does not have any effect on the reproduction of the data sequence due to the recording, and various data can be recorded that can be reproduced by an optical pickup that reproduces this data sequence, and that it is difficult to copy by illegal copying, and further difficult to find. To be able to.

  Conventionally, compact discs perform data processing on a data string to be recorded and then perform EFM modulation (Eight to Fourteen Modulation) to form a pit string having a period of 3T to 11T with respect to a predetermined basic period T. Audio data and the like are recorded.

  In contrast, a management data recording area is formed in the inner lead-in area, and a desired performance or the like can be selectively reproduced by a TOC (Table Of Contents) recorded in the recording area. Has been made.

  The compact disc on which various data is recorded in this way has an IFPI (International Federation of the Phonographic Industry) code recording area for the purpose of preventing piracy on the inner periphery of the lead-in area. The recording area is marked with a code indicating the manufacturer, manufacturing location, disk number, etc., so that the history of the compact disk can be visually confirmed.

  By the way, in such an inscription, it is considered that the illegal copy can be identified by the presence or absence of this inscription by checking the history of the compact disc. However, this stamp has a drawback that it is difficult to reproduce by an optical pickup of a compact disc player because it is for visual confirmation. Thus, in order to identify the illegal copy by the stamp and reflect the presence or absence of the stamp in the reproduction process, a dedicated reproduction mechanism is eventually required to reproduce the stamp.

  In addition, the codes recorded by these methods are recorded by the same method as normal pits and confirmed by visual observation, by removing the protective film and the aluminum reflective film of the compact disc and creating a stamper, etc. There was a problem that duplication was possible and this caused illegal copying.

As a result, it is possible to record various data that can be reproduced by an optical pickup that reproduces audio data and difficult to copy by illegal copying without affecting the reproduction of audio data by a pit row. If possible, this data can be used to eliminate illegal copying.
JP 2000-195049 A

  The present invention has been made in consideration of the above points, and has no effect on the reproduction of data by a pit row or the like, can be reproduced by an optical pickup for reproducing the data by the pit row or the like, and illegally copied. Disc production device, signal processing circuit, disc production method, signal processing method, disc, optical disc playback device, which can record data that prohibits illegal copying, and it is difficult to copy depending on The present invention intends to propose a demodulation circuit, an optical disc reproducing method, and a demodulation method.

In order to solve such a problem, the invention of claim 1 is applied to a disc production apparatus, and main modulation signal generating means for generating a main modulation signal according to main data, and according to the main modulation signal. Recording beam irradiation means for forming a pit row or mark row on the disk by irradiation of the recording beam, and a secondary modulation signal for generating a secondary modulation signal according to the key data used for decoding the main data Generating means, and position displacing means for displacing the irradiation position of the recording beam in the inner and outer circumferential directions in accordance with the secondary modulation signal, wherein the secondary modulation signal generating means is a pseudo-random number 2 It has a binary sequence generating means for generating decimal sequence, so as to displace the inner and outer circumferential direction of the pits or marks one bit of said key data allocated to a plurality of the pits or marks, and continuous That said inner periphery direction of displacement of the pit or mark to change in accordance with the binary sequences, the key data by encrypting by the binary sequences to generate a modulated signal of the sub.

The invention according to claim 7 is applied to a signal processing circuit used in a disk production apparatus for exposing a disk master, and the disk production apparatus performs irradiation of a recording beam in accordance with a main modulation signal. Recording beam irradiating means for forming a pit row or mark row on the basis of the track center by the pit row or mark row, and the irradiation position of the recording beam in accordance with a secondary modulation signal Position displacement means for displacing in the circumferential direction, and the signal processing circuit is used for main modulation signal generation means for generating the main modulation signal according to main data, and for decoding the main data. depending on the key data, and a sub-modulation signal generation means for generating a modulated signal of the sub-modulation signal generation means of the secondary generates the binary sequences are pseudo-random number Has Decimal sequence generating means, said outer circumferential direction in the pits or marks the 1-bit key data so as to assign a plurality of said pits or marks are displaced in the inner and outer circumferential direction of the pits or marks, and successive The key data is encrypted by the binary number sequence so that the displacement of the second modulation signal is changed according to the binary number sequence, and the secondary modulation signal is generated.

The invention of claim 8 is applied to a signal processing circuit used in a disk production apparatus for exposing a disk master, and the disk production apparatus generates a main modulation signal according to main data. Signal generation means, recording beam irradiation means for forming a pit row or mark row on the disc master by irradiation of a recording beam according to the main modulation signal, and a track center by the pit row or mark row as a reference. And a position displacing means for displacing the irradiation position of the recording beam in the inner and outer peripheral directions of the disc master according to the sub modulation signal, and the signal processing circuit is a key used for decoding the main data. depending on the data, and a sub-modulation signal generation means for generating a modulated signal of the sub-modulation signal generation means of the secondary generates binary sequences is a pseudorandom number 2 Has a number sequence generation means, said outer circumferential direction in the pits or marks the 1-bit key data so as to assign a plurality of said pits or marks are displaced in the inner and outer circumferential direction of the pits or marks, and successive The key data is encrypted by the binary number sequence so that the displacement of the second modulation signal is changed according to the binary number sequence, and the secondary modulation signal is generated.

The invention according to claim 9 is applied to a disc production method, wherein a main modulation signal generating step for generating a main modulation signal according to main data and a recording beam corresponding to the main modulation signal are generated. A recording beam irradiation step for forming a pit row or a mark row on the disc by irradiation, and a secondary modulation signal generation step for generating a secondary modulation signal in accordance with the key data used for decoding the main data And a position displacement step of displacing the irradiation position of the recording beam in the inner and outer circumferential directions of the disk in accordance with the sub modulation signal, and the sub modulation signal generation step is a pseudo-random number 2 comprising the step of binary sequence generator for generating decimal sequence, displacing the inner periphery direction of the pits or marks one bit of said key data allocated to a plurality of the pits or marks Sea urchin, and said inner periphery direction of displacement of the pit or mark continuously to change in accordance with the binary sequences, the key data by encrypting by the binary sequences to generate a modulated signal of the sub.

The invention of claim 1 3, applied to a signal processing method for use in a disk production apparatus for exposing the original disc, the disc production apparatus, the disk by the irradiation of the recording beam in accordance with the main modulation signal Recording beam irradiating means for forming a pit row or mark row on the master, and a track center by the pit row or mark row as a reference, the irradiation position of the recording beam in accordance with the secondary modulation signal Position displacement means for displacing in the inner and outer peripheral directions, and the signal processing method is for generating a main modulation signal according to main data and for decoding the main data. A sub-modulation signal generating step for generating the sub-modulation signal in accordance with key data used, wherein the sub-modulation signal generation step is a pseudo-random number. A binary sequence generation step of generating a binary sequence, wherein one bit of the key data is allocated to a plurality of the pits or marks, and the pits or marks are displaced in the inner and outer peripheral directions, and the continuous The secondary modulation signal is generated by encrypting the key data with the binary number sequence so that the displacement of the pits or marks in the inner and outer peripheral directions is changed according to the binary number sequence.

The invention of claim 1 4, applied to a signal processing method for use in a disk production apparatus for exposing the original disc, the disc production apparatus, in accordance with the main data, the main of which generates a main modulated signal A modulation signal generating means, a recording beam irradiation means for forming a pit row or a mark row on the disc master by irradiation of a recording beam according to the main modulation signal, and a track center by the pit row or mark row as a reference And a position displacing means for displacing the irradiation position of the recording beam in the inner and outer peripheral directions of the disc master according to the sub modulation signal, and the signal processing method is used for decoding the main data. A sub-modulation signal generation step for generating the sub-modulation signal according to the key data to be generated, wherein the sub-modulation signal generation step is a binary number system that is a pseudo-random number A binary sequence generation step for generating a sequence, wherein one bit of the key data is assigned to a plurality of the pits or marks to displace the pits or marks in the inner and outer peripheral directions, and the continuous pits or The secondary modulation signal is generated by encrypting the key data with the binary number sequence so that the displacement of the mark in the inner and outer peripheral directions is changed according to the binary number sequence.

Further, the invention of claim 15 is applied to a disc in which pit rows or mark rows are formed along a spiral or concentric track and main data is recorded, and the track center of the track is used as a reference. A pit or mark is formed by displacement in the inner and outer peripheral directions, and key data used for decoding the main data is recorded, and the displacement of the pit or mark in the inner and outer peripheral directions is a pseudo-random number 2 A displacement corresponding to a result of encrypting the key data by a decimal number sequence , wherein one bit of the key data is assigned to the plurality of pits or marks, and the inner and outer peripheral directions in the continuous pits or marks Is a displacement corresponding to the binary number series .

The invention of claim 2 1, applied to an optical disk reproducing apparatus, from the returning light obtained by irradiating a laser beam on the optical disc, the signal level changes according to the pit row or the mark row is formed on the optical disc Reproduction signal detection means for detecting a reproduction signal, main demodulation means for binaryly identifying the reproduction signal and reproducing main data recorded by the pit row or mark row, and inner and outer peripheral directions with reference to the track center Displacement detection means for outputting a displacement detection signal whose signal level changes in accordance with the displacement of the pit or mark on the track, and the pit or mark in the inner and outer circumferential directions with reference to the track center by processing the displacement detection signal Sub-demodulation means for reproducing the key data used for decrypting the main data recorded by the displacement of , A binary number sequence generating means for generating a binary number sequence that is a pseudo-random number, and by calculating the displacement detection signal based on the binary number sequence, one bit is formed in the inner and outer peripheral directions by the plurality of pits or marks. The key data is reproduced in which the displacement in the inner and outer circumferential directions of the continuous pits or marks is a displacement corresponding to the binary number series .

The invention of claim 28 is applied to a demodulating circuit used in an optical disc reproducing device, and the optical disc reproducing device uses a return beam obtained by irradiating the optical disc with a laser beam to form a pit train formed on the optical disc. Or reproduction signal detection means for detecting a reproduction signal whose signal level changes according to the mark string, and main demodulation means for binary-identifying the reproduction signal and reproducing the main data recorded by the pit string or mark string And a displacement detection means for outputting a displacement detection signal whose signal level changes according to the displacement of the pits or marks in the inner and outer circumferential directions with reference to the track center, and the demodulation circuit is a pseudo-random number A binary number sequence generating means for generating a binary number sequence, wherein one bit is converted into a plurality of bits by the arithmetic processing of the displacement detection signal based on the binary number sequence; Key data used for decryption of the main data, which is recorded by displacement in the inner and outer circumferential directions of the data or mark, and in which the displacement in the inner and outer circumferential directions of the continuous pits or marks is a displacement according to the binary number series Play.

The invention of claim 29 is applied to a demodulation method used in an optical disk reproducing device, and the optical disk reproducing device uses a return beam obtained by irradiating the optical disk with a laser beam to form a pit train formed on the optical disk. Or reproduction signal detection means for detecting a reproduction signal whose signal level changes according to the mark string, and main demodulation means for binary-identifying the reproduction signal and reproducing the main data recorded by the pit string or mark string And displacement detection means for outputting a displacement detection signal whose signal level changes in accordance with the displacement of the pit or mark in the inner and outer circumferential directions with reference to the track center, and the demodulation method is a pseudo-random number A step of generating a binary number sequence for generating a binary number sequence, and the calculation processing of the displacement detection signal based on the binary number sequence allows a plurality of bits to be A key used for decoding the main data, which is recorded by displacement in the inner and outer peripheral directions of the recorded pit or mark, and in which the displacement in the inner and outer peripheral direction in successive pits or marks is a displacement corresponding to the binary number series Play the data.

The invention of claim 3 0, then applied to an optical disc reproducing method, from return light obtained by irradiating a laser beam on the optical disc, the signal level changes according to the pit row or the mark row is formed on the optical disc A reproduction signal detection step for detecting a reproduction signal, a main demodulation step for binary-identifying the reproduction signal and reproducing main data recorded by the pit string or mark string, and an internal / external reference based on the track center A displacement detection step of outputting a displacement detection signal whose signal level changes according to the displacement of the pit or mark in the circumferential direction, and processing of the displacement detection signal, the inner and outer circumferential directions with reference to the track center. A sub-demodulation step for reproducing the key data used for decrypting the main data recorded by the displacement of the pits or marks. The sub-demodulation step includes a binary number sequence generation step of generating a binary number sequence that is a pseudo-random number, and a plurality of 1 bits are obtained by the arithmetic processing of the displacement detection signal based on the binary number sequence. Used for decoding the main data, which is recorded by displacement in the inner and outer peripheral directions of the pit or mark, and in which the displacement in the inner and outer peripheral directions in the continuous pit or mark is a displacement according to the binary series Play key data.

According to the structure of claim 1 , claim 7, claim 8, claim 9, claim 13, or claim 14 , reproduction of main data recorded by pits or marks is made difficult to detect the recording of key data. The key data can be recorded so as not to damage the data. The key data can be recorded so that it is difficult to copy by illegal copying and can be reproduced by an optical pickup that reproduces the main data.

  Further, according to the configurations of claims 16 and 17, the reproduction of the data by the pit row or the like is not affected at all, the data can be reproduced by the optical pickup for reproducing the data by the pit row or the like, and by illegal copying. It is possible to provide a signal processing method capable of recording data that prohibits illegal copying, making it difficult to copy and even difficult to find.

According to the configuration of claim 15 , the reproduction of the data by the pit string or the like is not affected at all, and the data by the pit string or the like can be reproduced by the optical pickup for reproduction, and the illegal copy can be copied. Therefore, it is possible to provide a disc on which data that prohibits illegal copying is recorded.

According to the second aspect 1, it is possible to correspond to the configuration of the recording reproducing the key data from the optical disk. This has no effect on the reproduction of the main data by the pit row etc., and can be reproduced by the optical pickup for reproducing the main data by the pit row etc., and it is difficult to copy by illegal copying. The key data can be reproduced from the optical disk on which the key data is recorded, which is difficult to find.

Thus, according to the configurations of claims 28 , 29 , and 30 , the data can be reproduced by the optical pickup that reproduces the data by the pit row without affecting the reproduction of the data by the pit row or the like. In addition, a demodulating circuit that can reproduce the data that prohibits illegal copying from an optical disk on which the data that prohibits illegal copying is recorded, which is difficult to copy by illegal copying, and is difficult to find. A method and an optical disc reproducing method can be provided.

  According to the present invention, there is no influence on the reproduction of data by a pit row or the like, it can be reproduced by an optical pickup that reproduces data by this pit row or the like, and it is difficult to copy by illegal copying. In addition, it is possible to record data that prohibits illegal copying, making it difficult to find.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

(1) Configuration of Embodiment FIG. 1 is a block diagram showing an optical disc apparatus according to an embodiment of the present invention. The optical disk apparatus 1 records the audio data D1 output from the digital audio tape recorder 3 by exposing the disk master 2.

  That is, in this optical disc apparatus 1, the spindle motor 4 drives the disc master 2 to rotate, and outputs an FG signal FG whose signal level rises every time it rotates by a predetermined angle from the FG signal generation circuit held at the bottom. The spindle servo circuit 5 controls the rotational speed of the spindle motor 4 in accordance with the exposure position of the disk master 2 with reference to the FG signal FG, thereby rotating the disk master 2 at a predetermined rotational speed.

  The recording laser 7 is constituted by a gas laser or the like, and emits a laser beam L1 for exposure of the disc master 2. The optical modulator 8A is composed of, for example, an electroacoustic optical element, and emits the laser beam L1 by performing on-off modulation in accordance with an EFM (Eight to Fourteen Modulation) signal S2 output from the modulation circuit 9.

  The optical deflector 8B is composed of, for example, an electroacoustic optical element, and diffracts and emits the laser beam L2 output from the optical modulator 8A in accordance with the key modulation signal KS output from the key modulation circuit 10. The laser beam L2 is emitted while changing the emission direction to a direction corresponding to the inner and outer circumferential directions of the disc master 2.

  The mirror 12 bends the optical path of the laser beam L3 output from the optical deflector 10 and emits it toward the disc master 2. The objective lens 13 condenses the light emitted from the mirror 12 on the recording surface of the master disc 2. The mirror 12 and the objective lens 13 are sequentially moved from the inner peripheral side to the outer peripheral side of the disc master 2 in synchronization with the rotation of the disc master 2 by a thread mechanism (not shown).

  As a result, the optical disc apparatus 1 sequentially displaces the condensing position of the laser beam L3 from the inner peripheral side to the outer peripheral side of the disc master 2, and forms a spiral track on the disc master 2. Further, in this track formation process, the optical disk apparatus 1 sequentially turns on and off the laser beam L1 by the optical modulator 8A according to the EFM signal S2, thereby sequentially forming pit rows along the track according to the EFM signal S2. Further, the emission direction of the laser beam L2 is displaced by the optical deflector 8B, and the pits are displaced in the inner and outer circumferential directions of the disc master 2 in accordance with the key modulation signal KS.

  Thus, in this optical disc apparatus 1, the optical disc produced from this master disc 2 is reproduced under the tracking control with the same characteristics as the conventional compact disc player, and the pit train is generated with the same phase margin as the conventional one. The pits in the inner and outer peripheral directions of the disc master 2 are set to a small value so that the data according to the above can be reproduced, that is, the reproduction of the data recorded by the pit train is not impaired. Specifically, in this embodiment, this displacement is at most 1/50 or less of the track pitch.

  The digital audio tape recorder 3 outputs the audio data D1 to the encryption circuit 15. The encryption circuit 15 encrypts the audio data with a DES (Data Encryption Standard) code based on the key data KY, and outputs the encrypted data.

  The subcode generator 16 sequentially generates and outputs subcode data SC according to a format defined for the compact disc. The modulation circuit 9 generates an EFM signal S2 by processing the output data S1 and the subcode SC of the encryption circuit 15 in accordance with a format defined for the compact disc. That is, the modulation circuit 9 adds an error correction code to the output data S1 and the subcode data SC of the encryption circuit 15, performs interleaving processing, and further performs EFM modulation to generate an EFM signal S2.

  Thereby, in the optical disc apparatus 1, the audio data D1 is encrypted and recorded on the disc master 2 by a pit string.

  The key modulation circuit 10 generates and outputs a key modulation signal KS based on the key data KY, whereby the optical disk apparatus 1 records the key data KY by displacement in the inner and outer peripheral directions of the pits. In the optical disc apparatus 1, key data KY is generated by a read-only memory or the like.

  FIG. 2 is a block diagram showing the key modulation circuit 10 in detail. As shown in FIG. 3, the key modulation circuit 10 inputs the EFM signal S2 (FIG. 3 (A)) to the PLL circuit (Phase Locked Loop) 20, where the clock CK (FIG. 3 (B)) is received from the EFM signal S2. ).

  The synchronization detection circuit 21 sequentially latches the EFM signal S2 with reference to the clock CK, and detects the synchronization pattern from the EFM signal S2 by determining the continuous logic level. The synchronization detection circuit 21 outputs a frame clock FCK whose logic level rises at the cycle of this synchronization pattern. Thus, in the compact disc format, a synchronization pattern is arranged at the head of each frame, and each frame is composed of 588 channel clocks. Therefore, the synchronization detection circuit 21 is a frame whose logic level rises every 588 clock cycles. The clock FCK is output.

  The subcode detection circuit 22 monitors the EFM signal S2 with reference to the clock CK, and decodes the subcode from the EFM signal S2. Further, the subcode detection circuit 22 monitors time information in the decoded subcode, and outputs a 1-second detection pulse SECP in which the signal level rises every time this time information changes by 1 second. Thus, in the compact disk format, 98 frames are allocated per second, so that the subcode detection circuit 22 outputs a 1-second detection pulse SECP so that the signal level rises at the 98 pulse period of the frame clock (FCK). Will do.

  The counter 23 is a counter that increments the frame clock FCK, and resets the count value CT when the one-second detection pulse SECP rises. As a result, the counter 23 forms a ring counter in which the count value CT circulates in a cycle of 1 second, and the count value CT changes in synchronization with the frame clock FCK.

  The data selector 24 outputs data held with the count value CT of the counter 23 as an address. Here, the count value CT of the counter 23 is cyclically changed by the number of frames per second (98 frames) in synchronization with the synchronization pattern, so that the data selector 24 uses the count value CT as an address. Thus, 98 types of data are sequentially output in synchronization with the synchronization pattern. Further, in the count value CT of the counter 23, the count value circulates in a cycle of 1 second by the 1-second detection pulse SECP, so that the data selector 24 repeats these 98 types of data in a cycle of 1 second.

  In this embodiment, the data selector 24 is assigned 1-bit data as the 98 types of data, and repeats at a 1-second cycle to output the 98-bit data in synchronization with the synchronization pattern. Yes. Further, each bit of the 54-bit key data KY is assigned to a predetermined bit of the 98-bit data, and each bit of data having no meaning is assigned to the remaining 44-bit bits. In this embodiment, fixed value data KZ is assigned as data having no meaning.

  The M-sequence generation circuit 25 includes a plurality of cascade-connected flip-flops and an exclusive OR circuit, and sets initial values in the plurality of flip-flops according to the frame clock FCK output from the synchronization detection circuit 21. Further, the M-sequence generation circuit 25 sequentially transfers the contents set in this manner in synchronization with the clock CK, and returns the feedback between predetermined stages, whereby an M-sequence random number in which logic 1 and logic 0 appear with equal probability. Data MS is generated. As a result, the M-sequence generation circuit 25 outputs random number data MS that is a binary sequence of pseudo-random numbers synchronized with the clock CK so that the same pattern is repeated in one frame cycle which is 588 clock cycles.

  The exclusive OR circuit (X) 27 receives the random number data MS and the output data KD of the data selector 24, and outputs an exclusive OR signal MS1 thereof (FIG. 3C). That is, the exclusive OR circuit 27 outputs the random number data MS as it is when the output data KD of the data selector 24 is logic 0, whereas the exclusive OR circuit 27 outputs the random number data MS when the output data KD of the data selector 24 is logic 1. Output with the logic level inverted. As a result, the exclusive OR circuit 27 modulates the key data KY constituting the output data KD with a random number and outputs it.

  The flip-flop 28 latches and outputs the output data MS1 of the exclusive OR circuit 27 with reference to the rising edge of the EFM signal S2 (FIG. 3 (D)). Here, in this embodiment, the scanning start end edge of each pit corresponds to the rising edge of the EFM signal S2 in the optical disc produced from the disc master 2 by the exposure of the disc master 2 by the EFM signal S2. become. As a result, the flip-flop 28 latches the output data MS1 assigned at the timing of starting each pit from the output data MS1 of the exclusive OR circuit 27 that is sequentially output in the clock cycle that is the reference cycle for pit formation. Until the formation of at least one pit is completed, the logic level of the latched output data MS1 is maintained.

  The amplifier circuit 29 is a driver amplifier that drives the optical deflector 8B, and amplifies the output signal of the flip-flop 28 and outputs the amplified signal to the optical deflector 8B as a key modulation signal KS. As a result, the amplification circuit 29 changes the laser beam irradiation position in the inner and outer circumferential directions of the disc master 2 in units of pits. The amplification circuit 29 has its gain set so that the displacement amount is at most 1/50 of the track pitch or less, so that the optical disk apparatus 1 can reproduce the data recorded by the pit string. It is made so as not to damage.

  Thus, in this embodiment, the exposed master disk 2 is developed and electroformed to create a mother disk, and a stamper is formed from the mother disk. Further, an optical disc is produced from this stamper in the same manner as a normal compact disc production process.

  As a result, in this embodiment, the audio data D1 encrypted by the pit string is recorded, and an optical disk on which the key data KY is recorded by the displacement in the inner and outer peripheral directions of each pit P is created (FIG. 3). (E-2)). That is, in a normal compact disc, pits P are sequentially formed on the track center along the track in accordance with the EFM signal S2, and audio data is recorded according to the pit length and the interval between the pits ( FIG. 3 (E-1)). On the other hand, in the optical disc according to this embodiment, the audio data encrypted by each pit length and the interval between each pit is recorded, and the audio data is encrypted by the displacement of each pit P in the inner and outer peripheral directions. Key data KY for canceling is recorded.

  FIG. 4 is a block diagram of the optical disc apparatus 30 that reproduces the optical disc 31 thus created. In the optical disk device 30, the spindle motor 32 rotates the optical disk 31 under the condition of a constant linear velocity under the control of the servo circuit 33.

  The optical pickup 34 irradiates the optical disc 31 with a laser beam and receives the return light by a predetermined light receiving element, and generates a reproduction signal RF whose signal level changes according to the light intensity of the return light on the light receiving surface of the light receiving element. Output. Here, the signal level of the reproduction signal RF changes corresponding to the pits recorded on the optical disk 31.

  Further, the optical pickup 34 processes the reception result of the return light by a so-called push-pull method, so that the push-pull signal whose signal level changes in accordance with the pit position with respect to the laser beam irradiation position in the inner and outer peripheral directions of the optical disc 31. PP is generated. The optical pickup 34 generates and outputs a focus error signal whose signal level changes according to the focus error amount.

  In the servo circuit 33, the push-pull signal PP is band-limited to generate a tracking error signal whose signal level changes in accordance with the detrack amount of the laser beam irradiation position with respect to the track center. The pickup 34 is tracking-controlled. The servo circuit 33 controls the focus of the optical pickup 34 with a focus error signal.

  The high-pass filter (HPF) 35 suppresses the low-frequency component of the push-pull signal PP, so that the laser beam for the track center is changed from the push-pull signal PP whose signal level changes according to the pit position with respect to the laser beam irradiation position. A displacement detection signal HPP whose signal level changes according to the position of the pit relative to the track center is removed by removing the detrack amount component at the irradiation position.

  The binarization circuit 36 binarizes the reproduction signal RF with a predetermined reference level and creates a binarized signal BD.

  The PLL circuit 37 reproduces the channel clock CCK of the reproduction signal RF by operating on the basis of the binarized signal BD.

  The EFM demodulation circuit 38 reproduces the reproduction data corresponding to the EFM modulation signal S2 by sequentially latching the binarized signal BD with reference to the channel clock CCK. Further, the EFM demodulating circuit 38 performs EFM demodulation of the reproduction data, delimits the demodulated data in units of 8 bits with reference to the frame sync, deinterleaves the generated 8-bit unit signal, and performs ECC (Error Correcting Code). Output to the circuit 39.

  The ECC circuit 39 performs error correction processing on the output data based on the error correction code added to the output data of the EFM demodulation circuit 38, and reproduces and outputs the audio data thus encrypted.

  The encryption processing circuit 40 decrypts the audio data with the key data KY detected by the key detection circuit 42 and outputs the result.

  The digital / analog conversion circuit (D / A) 41 performs a digital / analog conversion process on the audio data D1 output from the encryption processing circuit 40, and outputs an audio signal S4 composed of an analog signal.

  The key detection circuit 42 processes the displacement detection signal HPP on the basis of the channel clock CCK and the binary signal BD, thereby reproducing the key data KY and outputting it to the encryption processing circuit 40.

  FIG. 5 is a block diagram showing the key detection circuit 42 in detail. In the key detection circuit 42, the subcode detection circuit 52 monitors the binary signal BD with reference to the channel clock CCK, and decodes the subcode information from the binary signal BD. Further, the subcode detection circuit 52 monitors time information in the decoded subcode information, and outputs a 1-second detection pulse SECP in which the signal level rises every time this time information changes by 1 second.

  The pit detection circuit 54 sequentially latches the binarized signal BD at the timing of the channel clock CCK, and detects the timing at which the pit rises from the binarized signal BD by comparing two consecutive latch results. The pit detection circuit 54 outputs the edge detection signal PT at the timing when the pit rises from the detection result. Similarly, the pit detection circuit 54 detects the timing at which the pit has fallen, and outputs a center detection signal CTP at a substantially central portion of each pit based on the detection result of the timing at which the corresponding pit has risen.

  The synchronization detection circuit 55 detects the synchronization pattern by sequentially latching the binarized signal BD with reference to the channel clock CCK and determining the continuous logic level. Thereby, as shown in FIG. 6, the synchronization detection circuit 55 sets the set pulse FSET (FIG. 6 (A3), (B) and (D)) in which the signal level rises by one clock cycle at the timing when the synchronization pattern starts, A clear pulse FCLR (FIG. 6C) in which the signal level rises with a delay of one clock cycle from the set pulse FSET is generated and output.

  Accordingly, in the binarized reproduction signal BD (FIG. 6 (A1) and (A2)), the synchronization detection circuit 55 detects the synchronization pattern by detecting it 98 times per second in a period of 588 clocks. The clear pulse FCLR and the set pulse FSET are output in synchronization with the synchronization pattern.

  The M series generation circuit 56 initializes the address with reference to the clear pulse FCLR, and then sequentially advances the address by the channel clock CCK to access the built-in read-only memory, and thereby the M generated by the optical disc apparatus 1 M-sequence random number data MX corresponding to the sequence random number data MS is generated.

  As a result, the key detection circuit 42 reproduces various reference signals necessary for reproducing the key data KY corresponding to the processing in the optical disc apparatus 1.

  In the key detection circuit 42, an analog / digital conversion circuit 57 performs an analog / digital conversion process on the displacement detection signal HPP based on the channel clock CCK, and outputs an 8-bit digital reproduction signal. The polarity inversion circuit (-1) 58 inverts the polarity of the digital reproduction signal and outputs it.

  The latch circuit 59 latches the M-sequence random number data MX at the timing of the edge detection signal PT, and thereby, according to the timing corresponding to the processing timing of the exclusive OR circuit 27 in the key modulation circuit 10 described above with reference to FIG. The latched data MX is held until one pit is completed after the M-sequence random number data MX is latched at the timing of pit formation start.

  The selector 60 selects and outputs a digital signal directly input from the analog-digital conversion circuit 57 and a digital signal obtained by inverting the polarity input from the polarity inversion circuit 58 according to the logic level of the output data MZ of the latch circuit 59. To do. That is, the selector 60 selects and outputs a directly input digital signal when the output data MZ of the latch circuit 59 is logic 1, and conversely, when the output data MZ of the latch circuit 59 is logic 0, the polarity is selected. Select the inverted digital signal. As a result, the selector 60 reproduces the logical level of the key data KY (KD) modulated by the M-sequence random number data MS with the multi-value data, and outputs the reproduction data RX with the multi-value data.

  The adder 62 is a 16-bit digital adder that adds the reproduction data RX and the output data AX of the accumulator (ACU) 63 and outputs the result. The accumulator 63 is composed of a 16-bit memory that holds the output data of the adder 62, and forms a cumulative adder together with the adder 62 by feeding back the held data to the adder 62. That is, the accumulator 63 clears the content held by the clear pulse FCLR, and then cumulatively adds the output data of the adder 62 in synchronization with the output signal CTP of the pit detection circuit 54.

  As a result, the adder 62 and the accumulator 63 add or subtract the displacement amount of the pit detected at the center of each pit according to the M-sequence random number data MS and accumulate, and repeat this accumulation operation in one frame period. Has been made.

  The binarization circuit 64 binarizes the output data AX of the accumulator 63 with a predetermined reference value and outputs the binarized data. Accordingly, the binarization circuit 64 converts the reproduction data RX of the multi-value key data KY (KD) reproduced by the selector 60 into binary data.

  The shift register (SR) 65 is a 98-bit shift register, and sequentially takes and transfers the binarized data output from the binarization circuit 64 at the timing when the set pulse FSET rises.

The flip-flop (F / F) 66 fetches and holds the output data of the shift register 65 in bit parallel at the timing of the 1-second detection pulse SECP. As a result, in the key detection circuit 42, the data KD composed of the key data KY and the fixed value data KZ is held in the flip-flop 66. The key detection circuit 42 selectively outputs predetermined bits of the flip-flop 66 to supply the key data KY to the encryption processing circuit 40 to release the encryption of the audio data.
(2) Operation of Example In the above configuration, in the manufacturing process of the optical disc 31 according to this example, the disc master 2 is exposed by the optical disc apparatus 1 (FIG. 1), and this disc master 2 is developed and electroformed. A mother disk is created, and a stamper and an optical disk are created from the mother disk.

  In the exposure of the disc master 2, in the optical disc apparatus 1, the audio data D1 output from the digital audio tape recorder 3 is input to the encryption circuit 15, where it is encrypted with predetermined key data KY. As a result, the audio data D1 is processed so that it cannot be auditioned unless the key data KY is used, and the subsequent modulation circuit 9 is processed in the same manner as the processing in a normal compact disc and converted into the EFM signal S2.

  In the optical disk apparatus 1, the laser beam L1 is controlled to be turned on / off by the EFM signal S2, and the laser beam L2 controlled to be turned on / off is sequentially condensed from the inner peripheral side to the outer peripheral side of the rotating disk master 2, thereby A spiral track is formed on the outer peripheral side, and audio data D1 encrypted by a pit string is recorded along this track.

  In this manner, while the audio data D1 is recorded by the pit string, in the optical disc apparatus 1, the key modulation circuit 10 generates the key modulation signal KS by modulating the key data KY with difficulty in decoding, and this key modulation. The optical deflector 8B is driven by the signal KS and the condensing position of the laser beam L3 is displaced in the inner and outer peripheral directions of the disc master 2, whereby the key data KY is recorded by the displacement in the inner and outer peripheral directions of the pits.

  Thus, in this embodiment, it is possible to provide the audio data D1 encrypted so that it cannot be auditioned without using the key data KY, and the key data KY by a single recording medium.

  The maximum displacement of the pits formed in this way is set to 1/50 of the track pitch, which makes it easy to displace the pits even when the information recording surface is observed with a microscope. So that it can not be found. Accordingly, it is possible to prevent illegal copying by making it difficult to analyze the displacement of the pits.

  In addition, since the amount of displacement is small, the reproduction signal can be processed with sufficient phase margin and amplitude margin in reproducing the audio data D1 recorded by the pit train, and thus the audio data recorded by the pit train can be reliably reproduced. it can. Incidentally, such a displacement of the pits in the inner and outer circumferential directions may affect the tracking control. However, when the amount of displacement is small to the extent according to this embodiment, the data recorded by the pit row can be reproduced with a tracking accuracy sufficient for practical use.

  That is, the key data KY (FIG. 2) has a meaning in the DES code 54-bit key data KY, assuming that 98 bits are allocated per second in the compact disc and 1-bit data is allocated to each frame. The data KZ having no fixed 44 bits is added and set in the data selector 24.

  The key data KY (KD) set in this way is 1 bit per frame by the detection of the synchronization pattern in the synchronization detection circuit 21 and the detection result SECP in the 1 second period detected by the subcode detection circuit 22. Is output from the data selector 24 so as to circulate in one second.

  Simultaneously and in parallel, in the M-sequence generation circuit 25, random number data MS, which is a binary number sequence in which logic 1 and logic 0 are generated with equal probability, is synchronized with the clock CK and the detection result FCK of the synchronization pattern. Is generated so as to be repeated for each frame.

  The key data KY (KD) is output from the data selector 24, and the exclusive OR with the random number data MS is obtained in the exclusive OR circuit 27, thereby being modulated by the random number data MS. At this time, since the random number data in the MS is a binary number sequence in which logic 1 and logic 0 are generated with equal probability, in the output data of the exclusive OR circuit 27 that is modulated, the logic 1 is almost equal to logic 1. A logical 0 will occur with equal probability.

  In the key modulation circuit 10, the output data MS1 generated in this way is latched at the rising edge of the EFM signal S2 in the flip-flop 28, so that one bit of the output data MS1 is generated in each pit formed on the disk master 2. Is selectively allocated, and the converging position of the laser beam L3 is displaced in the inner and outer peripheral directions of the disc master 2 by the optical deflector 8B in accordance with the 1-bit logic level. Recorded by circumferential displacement.

  At this time, in this embodiment, the key data KY (KD) is output from the data selector 24 at a cycle of 1 bit per frame, and the key data KY (KD) is modulated by the random number data MS and the pit P is displaced. As a result, in the optical disc, the pits P are irregularly displaced in the inner and outer circumferential directions.

  As a result, in this embodiment, each bit of the key data KY can be distributed and recorded in a plurality of pits, making it difficult to find the key data KY recorded by the displacement of the pits. That is, even when the information recording surface is observed with a microscope or the like, the pit string is observed as if it was modulated by noise, and the key data KY can be difficult to find by such visual observation. Thus, in this case, since one bit of the key data KY is assigned to the 588 channel clock, at least one bit of the key data KY is distributed and recorded in 50 or more pits.

  Further, at this time, the logic 1 and the logic 0 are generated with equal probability in the random number data MS, so that the displacement of the pits formed in this way is also the displacement toward the inner periphery and the displacement toward the outer periphery with respect to the track center. Will occur with almost equal probability. As a result, since this displacement is minute, even if various signals obtained from the optical pickup are observed, it is observed as if noise is mixed, and the presence or absence of key data KY is also confirmed by such waveform observation. It can be difficult to find.

  On the other hand, the pit displacement does not include an offset component which is a direct current component. Further, by latching by the flip-flop 28 and setting the displacement for each pit, when detecting the displacement of this pit, the higher frequency side than the push-pull signal PP for detecting the tracking error signal is detected. Although it is due to the SN that has been extracted and significantly deteriorated, the displacement can be easily detected. As a result, in this optical disc, the key data KY can be reproduced with a simple configuration that can be reproduced by an optical pickup having a conventional configuration, and illegal copying can be prevented.

  That is, in the optical disk device 30 of the optical disk 31 thus created (FIG. 4), the reproduction signal RF is binarized by the binarizing circuit 36 and then the EFM demodulating circuit 38, as in the conventional compact disk player. The error data is processed by the subsequent ECC circuit 39, whereby the encrypted audio data is reproduced. In the subsequent encryption processing circuit 40, the encryption is canceled by the separately acquired key data KY, so that the audio signal recorded by the pit string can be auditioned via the digital-analog conversion circuit 41.

  Further, in the optical disc apparatus 30, the push-pull signal PP obtained from the optical pickup 34 is band-limited by the high pass filter 35, so that the signal level changes according to the displacement amount in the inner and outer peripheral directions of the pits with a simple configuration. A detection signal HPP is detected.

  In the optical disk device 30, the displacement detection signal HPP is processed by the key detection circuit 42 to reproduce the key data KY.

  That is, in the key detection circuit 42 (FIG. 5), the displacement detection signal HPP is converted into a digital signal at a channel clock period by the analog-digital conversion circuit 57, and the polarity inversion circuit 58 generates a digital signal whose polarity is inverted. The

  These two systems of digital signals are selectively added by the output data MZ generated by latching the random number data MX generated on the basis of the synchronization pattern of the binary signal BD by the latch circuit 59 at the timing of the pits. Is input to the counter 62 and is cumulatively added with reference to the detection result FCLR of the synchronization pattern.

  That is, during recording, the output data of the analog-digital conversion circuit 57 is added or subtracted in accordance with the logic level of the output data of the exclusive OR circuit 27 (FIG. 2) at the rising timing of the EFM signal S2, and the addition is performed. As a result, the accumulated value AX as the subtraction result is accumulated in the accumulator 63 in the frame period. Further, at the timing when the synchronization pattern starts, the binary identification result of the accumulated value AX of the accumulator 63 is taken into the shift register 65, whereby the key data KY is demodulated.

  As a result, in the displacement detection signal HPP obtained from each pit, the displacement detection signal HPP is accumulated for one frame in this way even if the SN ratio is significantly deteriorated due to the minute displacement. By performing binary identification, the key data KY can be reproduced by performing binary identification with a high S / N ratio. This makes it possible to reliably reproduce the key data KY recorded difficult to find.

  In the key detection circuit 42, when the signal level of the displacement detection signal HPP is accumulated in the accumulator 63, the addition result of the adder 62 is taken in and accumulated at the timing of the central portion of each pit. As a result, the key detection circuit 42 accumulates the signal level at a timing when the signal level of the displacement detection signal HPP is sufficiently stable, and the detection accuracy is further improved.

  Accordingly, in the case of illegal copying, it may be considered that an illegally copied optical disk is produced by controlling on / off of the laser beam by the binary signal BD output from the binarization circuit 36. However, in this illegal copy, it is difficult to record the key data KY depending on the displacement of the pits. As a result, it is difficult to create an illegal copy of the optical disc 31 according to this embodiment.

  Further, when an optical disc by illegal copying in which only the pit row is copied in this way is reproduced by the optical disc apparatus according to this embodiment, the key data KY due to the pit displacement is lost, and the encrypted noise is lost. Thus, it becomes difficult to enjoy music normally. As a result, the value of the optical disk by illegal copying can be significantly reduced, and as a result, the spread of illegal copying can be prevented.

As a result, in this embodiment, the reproduction of the audio data by the pit row is not affected at all, and the key data can be reproduced by the optical pickup for reproducing the audio data and difficult to copy by illegal copying. Can be recorded.
(3) Effects of the embodiment According to the above configuration, it is difficult to find by processing the secondary data by the binary number sequence, displacing the pits in the inner and outer peripheral directions, and recording the secondary data related to the key data. The secondary data is recorded in the pit row so that the reproduction of the audio data row by the pit row is not affected. The audio data can be played back by an optical pickup and difficult to copy by illegal copying. , Key data and the like can be recorded.

  At this time, this binary number sequence is a binary number sequence generated by arithmetic processing using an initial value set at a period synchronized with the synchronization pattern of the main data, and logical 1 and logical 0 are generated with equal probability. This makes it even more difficult to find.

  In addition, it is possible to make it difficult to find out more reliably by calculating a plurality of binary number sequences for one bit of the sub data to generate a sub modulation signal.

  In the above-described embodiment, the case where one bit of key data is assigned to one frame has been described. However, the present invention is not limited to this, and a plurality of bits may be assigned to one frame. One bit of key data may be assigned to the frame. Further, instead of assigning key data bits based on audio data frames recorded by pit rows, one bit of key data may be assigned based on the number of pits.

  In the above-described embodiment, one bit of key data is allocated to one frame, so that one bit of key data is distributed and recorded in 50 or more pits. The number of pits to which 1 bit is assigned can be variously set as needed. By the way, according to the experimental results, it is possible to reproduce key data with a practically sufficient SN ratio by assigning one bit of key data to 20 or more pits.

  In the above-described embodiment, the case where the fixed bit data having no meaning is added to the key data and recorded is described. However, the present invention is not limited to this, and the error correction code is added to the key data for recording. You may make it carry out, and you may make it add and add the data of copyright.

  In the above embodiment, the case where the data encrypted by the pit string is recorded and the key data necessary for the decryption is recorded by the displacement of the pits in the inner and outer peripheral directions has been described. The present invention is not limited to this, and can be widely applied to recording various data such as recording identification data such as whether or not copying is possible instead of key data.

  In the above-described embodiment, the case where the accumulator is used to identify the accumulated value as binary data and reproduce the key data has been described. However, the present invention is not limited to this, and the accumulated value is reproduced as multivalued data. May be. In this way, multivalued data can be recorded by pit displacement.

  In the above-described embodiments, the case where the digital audio signal is recorded by EFM modulation has been described. However, the present invention is not limited to this, and various modulations such as 1-7 modulation, 8-16, and 2-7 modulation are possible. Can be widely applied to.

  In the above-described embodiment, the case where the key data is recorded on the entire surface of the optical disk has been described. However, the present invention is not limited to this. For example, the data may be recorded in a limited area such as a lead-in area.

  In the above-described embodiment, the case where desired data is recorded by the pit row has been described. However, the present invention is not limited to this, and can be widely applied to the case where desired data is recorded by the mark row.

  In the above-described embodiments, the case where the present invention is applied to an optical disk for recording audio data and its peripheral devices has been described for recording an audio signal. However, the present invention is not limited to this, and the present invention is not limited to this. The present invention can be widely applied to optical disks and peripheral devices.

  The present invention can be applied to, for example, an optical disc for recording audio data, and the recording apparatus and the reproducing apparatus.

It is a block diagram which shows the optical disk apparatus with which preparation of the optical disk based on the Example of this invention is provided. FIG. 2 is a block diagram showing a key modulation circuit of the optical disc apparatus in FIG. 1. 3 is a time chart for explaining the operation of the key modulation circuit of FIG. 2. It is a block diagram which shows the optical disk apparatus which reproduces | regenerates the optical disk produced with the optical disk apparatus of FIG. FIG. 5 is a block diagram showing a key detection circuit of the optical disc apparatus in FIG. 4. 6 is a time chart for explaining the operation of the key detection circuit of FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical disk apparatus, 2 ... Disc original disc, 10 ... Key modulation circuit, 21, 55 ... Synchronization detection circuit, 22, 52 ... Subcode detection circuit, 25 ... M series generation circuit, 30 ... Optical disk Device, 31 ... optical disc, 42 ... key detection circuit

Claims (30)

Main modulation signal generating means for generating a main modulation signal according to main data;
A recording beam irradiation means for forming a pit row or a mark row on the disc by irradiation of a recording beam in accordance with the main modulation signal;
Sub modulation signal generating means for generating a sub modulation signal according to key data used for decoding the main data;
Position displacement means for displacing the irradiation position of the recording beam in the inner and outer circumferential directions of the disk according to the sub modulation signal;
The sub modulation signal generating means includes
A binary sequence generating means for generating a binary sequence that is a pseudo-random number ;
One bit of the key data is assigned to the plurality of pits or marks to displace the pits or marks in the inner and outer peripheral directions, and the displacement in the inner and outer peripheral directions in the plurality of consecutive pits or marks is the 2 The disc production apparatus characterized in that the sub modulation signal is generated by encrypting the key data by the binary number sequence so as to change in accordance with the binary number sequence. The binary number sequence generation means includes:
The disk production apparatus according to claim 1, wherein the binary number sequence is generated using position information of the key data to be recorded. The binary sequence is
2. The binary number sequence generated by arithmetic processing using an initial value set at a period synchronized with the synchronization pattern of the main data, wherein logic 1 and logic 0 are generated with equal probability. The disc production apparatus described in 1. The position displacement means is
2. The disc production apparatus according to claim 1, wherein an irradiation position of the recording beam is displaced toward an inner peripheral side and / or an outer peripheral side of the disc with reference to a track center by the pit row or mark row. The position displacement means is
2. The disk production apparatus according to claim 1, wherein an irradiation position of the recording beam is displaced in an inner / outer circumferential direction of the disk with reference to the synchronization pattern of the main data. The position displacement means is
2. The recording beam irradiation position is displaced in the inner and outer circumferential directions of the disk within a range of displacement amounts in the inner and outer circumferential directions of the recording beam irradiation position due to the influence of noise. Disc production equipment. A signal processing circuit used in a disc production apparatus for exposing a disc master,
The disk production apparatus is
A recording beam irradiation means for forming a pit row or a mark row on the disc master by irradiation of a recording beam in accordance with a main modulation signal;
Position displacement means for displacing the irradiation position of the recording beam in the direction of the inner and outer circumferences of the disc master in accordance with a secondary modulation signal with reference to the track center by the pit row or mark row,
The signal processing circuit includes:
Main modulation signal generating means for generating the main modulation signal according to main data;
Sub modulation signal generating means for generating the sub modulation signal according to key data used for decoding the main data,
The sub modulation signal generating means includes
A binary sequence generating means for generating a binary sequence that is a pseudo-random number ;
One bit of the key data is assigned to a plurality of the pits or marks to displace the pits or marks in the inner and outer peripheral directions, and the displacement in the inner and outer peripheral directions in the continuous pits or marks is converted into the binary series. The signal processing circuit characterized in that the sub-modulated signal is generated by encrypting the key data with the binary number sequence so as to change in response . A signal processing circuit used in a disc production apparatus for exposing a disc master,
The disk production apparatus is
Main modulation signal generating means for generating a main modulation signal according to main data;
A recording beam irradiating means for forming a pit row or a mark row on the disc master by irradiation of a recording beam in accordance with the main modulation signal;
Position displacement means for displacing the irradiation position of the recording beam in the direction of the inner and outer circumferences of the disc master in accordance with a secondary modulation signal with reference to the track center by the pit row or mark row,
The signal processing circuit includes:
Sub modulation signal generating means for generating the sub modulation signal according to key data used for decoding the main data;
The sub modulation signal generating means includes
A binary sequence generating means for generating a binary sequence that is a pseudo-random number ;
One bit of the key data is assigned to a plurality of the pits or marks, and the pits or marks are displaced in the inner and outer circumferential directions, and the displacement in the inner and outer circumferential directions in the continuous pits or marks is converted into the binary series. The signal processing circuit characterized in that the sub-modulated signal is generated by encrypting the key data with the binary number sequence so as to change in response . A main modulation signal generating step for generating a main modulation signal according to the main data;
A recording beam irradiation step of forming a pit row or a mark row on the disk by irradiation of the recording beam according to the main modulation signal;
A sub-modulation signal generating step for generating a sub-modulation signal in accordance with the key data used for decoding the main data;
A position displacement step of displacing the irradiation position of the recording beam in the inner and outer circumferential directions of the disk according to the sub modulation signal,
The step of generating the secondary modulation signal includes:
A binary sequence generation step for generating a binary sequence that is a pseudo-random number ;
One bit of the key data is assigned to a plurality of the pits or marks to displace the pits or marks in the inner and outer peripheral directions, and the displacement in the inner and outer peripheral directions in the continuous pits or marks is converted into the binary series. The disk production method, wherein the sub-modulated signal is generated by encrypting the key data with the binary number sequence so as to be changed accordingly . The disc is a master disc for creating a mother disc used for optical disc production;
The disk production method according to claim 9 , wherein the mother disk is produced using the disk. The disc is a master disc for creating a stamper used for optical disc production;
The disc production method according to claim 9 , wherein the stamper is produced using the disc. The disc is a disc master used for production of an optical disc,
The disc production method according to claim 9 , wherein the optical disc is produced using the disc. A signal processing method used in a disc production apparatus for exposing a disc master,
The disk production apparatus is
A recording beam irradiation means for forming a pit row or a mark row on the disc master by irradiation of a recording beam in accordance with a main modulation signal;
Position displacement means for displacing the irradiation position of the recording beam in the direction of the inner and outer circumferences of the disc master in accordance with a secondary modulation signal with reference to the track center by the pit row or mark row,
The signal processing method includes:
A step of generating a main modulation signal to generate the main modulation signal according to main data;
A sub modulation signal generation step for generating the sub modulation signal according to key data used for decoding the main data, and
The step of generating the secondary modulation signal includes:
A binary sequence generation step for generating a binary sequence that is a pseudo-random number ;
One bit of the key data is assigned to a plurality of the pits or marks, and the pits or marks are displaced in the inner and outer circumferential directions, and the displacement in the inner and outer circumferential directions in the continuous pits or marks is converted into the binary series. The signal processing method, wherein the key data is encrypted by the binary number sequence so as to change in accordance with the sub-modulation signal. A signal processing method used in a disc production apparatus for exposing a disc master,
The disk production apparatus is
Main modulation signal generating means for generating a main modulation signal according to main data;
A recording beam irradiating means for forming a pit row or a mark row on the disc master by irradiation of a recording beam in accordance with the main modulation signal;
Position displacement means for displacing the irradiation position of the recording beam in the direction of the inner and outer circumferences of the disc master in accordance with a secondary modulation signal with reference to the track center by the pit row or mark row,
The signal processing method includes:
A sub-modulation signal generation step of generating the sub-modulation signal according to key data used for decoding the main data;
The step of generating the secondary modulation signal includes:
A binary sequence generation step for generating a binary sequence that is a pseudo-random number ;
One bit of the key data is assigned to a plurality of the pits or marks, and the pits or marks are displaced in the inner and outer circumferential directions, and the displacement in the inner and outer circumferential directions in the continuous pits or marks is converted into the binary series. The signal processing method, wherein the key data is encrypted by the binary number sequence so as to change in accordance with the sub-modulation signal. In a disc in which pit rows or mark rows are formed along spiral or concentric tracks and main data is recorded,
Pits or marks are formed in the inner and outer peripheral directions with reference to the track center of the track, and key data used for decoding the main data is recorded,
The displacement of the pits or marks in the inner and outer peripheral directions is
A displacement corresponding to a result of encrypting the key data by a binary number sequence that is a pseudo-random number , wherein one bit of the key data is assigned to a plurality of the pits or marks, and in the continuous pits or marks The disc according to claim 1, wherein the displacement in the inner and outer circumferential directions is a displacement corresponding to the binary number series . The displacement in the inner and outer circumferential directions is
The disc according to claim 15 , wherein the disc is an inner peripheral side and / or an outer peripheral side displacement from the track center. The disk according to claim 15 , wherein the disk is a disk master used for production of an optical disk. The disk according to claim 15 , wherein the disk is a mother disk used for production of an optical disk. The disk according to claim 15 , wherein the disk is a stamper used for production of an optical disk. The disk according to claim 15 , wherein the disk is an optical disk. Reproduction signal detecting means for detecting a reproduction signal whose signal level changes according to a pit row or a mark row formed on the optical disc from return light obtained by irradiating the optical disc with a laser beam;
Main demodulating means for binaryly identifying the reproduction signal and reproducing main data recorded by the pit string or mark string;
Displacement detection means for outputting a displacement detection signal whose signal level changes according to the displacement of the pits or marks in the inner and outer circumferential directions with reference to the track center;
Sub-demodulation means for reproducing the key data used for decoding the main data recorded by the displacement of the pits or marks in the inner and outer circumferential directions with respect to the track center by processing the displacement detection signal And
The secondary demodulating means includes:
A binary sequence generating means for generating a binary sequence that is a pseudo-random number ;
Through the calculation processing of the displacement detection signal based on the binary number sequence, 1 bit is recorded by the displacement in the inner and outer peripheral directions by the plurality of pits or marks, and the displacement in the inner and outer peripheral directions in the continuous pits or marks is An optical disc reproducing apparatus for reproducing the key data , which is a displacement corresponding to the binary number series . The displacement detection signal is
The optical disk reproducing apparatus according to claim 21 , wherein the signal is a signal whose polarity is switched in response to a displacement of the pits or marks in the inner and outer circumferential directions with respect to the track center. The secondary demodulating means includes:
Polarity inversion means for inverting the polarity of the displacement detection signal to generate an inversion signal of the displacement detection signal;
The optical disk reproducing apparatus according to claim 21 , wherein the key data is reproduced by selectively integrating the displacement detection signal and the inverted signal based on the binary number series. The secondary demodulating means includes:
Polarity inversion means for inverting the polarity of the displacement detection signal to generate an inversion signal of the displacement detection signal;
The key data is reproduced by selectively accumulating the displacement detection signal and the inverted signal based on the binary sequence based on the position of the synchronization pattern of the main data. 21. An optical disk reproducing device according to item 21 . The optical disk reproducing apparatus according to claim 21 , wherein the calculation process is a calculation process based on a position of a synchronization pattern of the main data. The binary sequence is
Claim 21, wherein the main processor using the initial value that is set in a cycle synchronized with the synchronization pattern data is generated by a binary sequence logic 1 and logic 0 are generated at equal probability An optical disk reproducing device according to claim 1. The main demodulation means is:
The optical disk reproducing device according to claim 21 , wherein the encryption of the main data is canceled by the key data. A demodulation circuit used in an optical disk reproducing device,
The optical disc playback apparatus comprises:
Reproduction signal detecting means for detecting a reproduction signal whose signal level changes according to a pit row or a mark row formed on the optical disc from return light obtained by irradiating the optical disc with a laser beam;
Main demodulating means for binaryly identifying the reproduction signal and reproducing main data recorded by the pit string or mark string;
Displacement detecting means for outputting a displacement detection signal whose signal level changes according to the displacement of the pit or mark in the inner and outer circumferential directions with reference to the track center;
The demodulation circuit includes:
A binary sequence generating means for generating a binary sequence that is a pseudo-random number ;
Through the calculation process of the displacement detection signal based on the binary number sequence, 1 bit is recorded by the displacement in the inner and outer peripheral directions of the plurality of pits or marks, and the displacement in the inner and outer peripheral directions in the continuous pits or marks is the A demodulation circuit for reproducing key data used for decoding the main data, which is a displacement corresponding to a binary number sequence . A demodulation method used in an optical disk reproducing device,
The optical disc playback apparatus comprises:
Reproduction signal detecting means for detecting a reproduction signal whose signal level changes according to a pit row or a mark row formed on the optical disc from return light obtained by irradiating the optical disc with a laser beam;
Main demodulating means for binaryly identifying the reproduction signal and reproducing main data recorded by the pit string or mark string;
Displacement detection means for outputting a displacement detection signal whose signal level changes according to the displacement of the pits or marks in the inner and outer circumferential directions with reference to the track center,
The demodulation method includes:
A binary sequence generation step for generating a binary sequence that is a pseudo-random number ;
Through the calculation process of the displacement detection signal based on the binary number sequence, 1 bit is recorded by the displacement in the inner and outer peripheral directions of the plurality of pits or marks, and the displacement in the inner and outer peripheral directions in the continuous pits or marks is the A demodulation method, wherein key data used for decoding the main data, which is a displacement corresponding to a binary number sequence, is reproduced. A step of detecting a reproduction signal for detecting a reproduction signal whose signal level changes according to a pit row or a mark row formed on the optical disc from return light obtained by irradiating the optical disc with a laser beam;
A main demodulation step of reproducing the main data recorded by the pit string or the mark string by binary-identifying the reproduction signal;
A displacement detection step of outputting a displacement detection signal whose signal level changes according to the displacement of the pits or marks in the inner and outer circumferential directions with reference to the track center;
By the processing of the displacement detection signal, sub-demodulation for reproducing key data used for decrypting the main data recorded by displacement of the pits or marks in the inner and outer circumferential directions with respect to the track center. With steps,
The sub-demodulation step comprises:
A binary sequence generation step for generating a binary sequence that is a pseudo-random number ;
Through the calculation process of the displacement detection signal based on the binary number sequence, 1 bit is recorded by the displacement in the inner and outer peripheral directions of the plurality of pits or marks, and the displacement in the inner and outer peripheral directions in the continuous pits or marks is the An optical disc reproducing method, wherein the key data is reproduced according to a binary number series .

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