JP4045599B2 - Information recording apparatus, information reproducing apparatus, and information recording medium - Google Patents

Description

  The present invention relates to an information recording device, an information reproducing device, and an information recording medium, and can be applied to, for example, a compact disc, its recording device, and a reproducing device.

  Conventionally, for example, in a compact disc composed of this type of optical information recording medium, after processing data to be recorded, EFM (Eight-to-Fourteen Modulation) modulation is performed, and thereby a predetermined basic period T is obtained. Pit trains with a period of 3T to 11T are formed, and thereby audio data and the like are recorded.

  Correspondingly, the compact disc player receives a return light by irradiating the compact disc with a laser beam, thereby obtaining a playback signal whose signal level changes according to the amount of the return light, and this playback signal is predetermined. A binarized signal is generated by binarizing according to the slice level. Further, a PLL circuit is driven from the binarized signal to generate a reproduction clock, and the binarized signal is sequentially latched by the reproduction clock, whereby a period 3T to 11T corresponding to a pit string formed on the compact disc. Generate playback data.

  The compact disc player decodes the reproduction data generated in this way by data processing corresponding to the data processing at the time of recording, and reproduces audio data and the like recorded on the compact disc.

  In such a compact disc, a code indicating the manufacturer name, manufacturing location, disc number, etc. is imprinted in an area where no data is recorded inside the lead-in area. It can be identified with the naked eye.

  There are two types of illegal copying. One is to produce a compact compact disc by creating a stamper from audio data obtained by reproducing a regular compact disc. The remaining one is a method of physically copying a pit shape formed on a regular optical disc.

When an illegal copy is identified by imprinting on a compact disc of a copy made in this way, once the imprint is copied, it becomes difficult to identify the illegal copy. In addition, since audio data can be reproduced without an inscription, it is difficult to completely prevent this type of copying.
JP-A-7-37255 JP-A-8-7340

  The present invention has been made in view of the above points, and an object of the present invention is to propose an information recording apparatus, an information reproducing apparatus, and an information recording medium that can effectively avoid illegal copying.

In order to solve this problem, the invention of claim 1 irradiates a recording medium with a laser beam, and forms a pit string or a space on the recording medium by a pit length and a space length based on a predetermined modulation signal, or by a mark length and a space length. In an information recording apparatus for recording a main data by forming a mark row, a modulation signal generating means for generating the modulation signal based on the main data and an initial physical interval on the recording medium And pseudo-random number generation means for repeatedly generating pseudo-random numbers and encrypted identification data for generating encrypted identification data by encrypting identification data for copyright protection of the main data using the pseudo-random numbers a generation unit, the control of the laser beam, the pit array of pit length and the space length or mark length and space length corresponding to the modulated signal Together to create a mark row, and a laser beam control means for providing a change of the corresponding encryption identification data in a direction perpendicular to the extending direction of the pits or marks against a pit or mark of the pit row or the mark row Prepare.

According to a seventh aspect of the present invention, in the information reproducing apparatus for reproducing the data recorded on the recording medium based on the return light obtained by irradiating the recording medium with a laser beam, the return light is received, A reproduction optical system that outputs a reproduction signal whose signal level changes according to pits or marks formed on the recording medium, and processes the reproduction signal to obtain the lengths of the pits and spaces, or the lengths of the marks and spaces The first reproduction processing means for outputting the main data recorded by the method, the pseudo random number generating means for repeatedly generating pseudo random numbers by initializing at a physical constant interval on the recording medium, and the pseudo random numbers processing the reproduction signal, wherein the control of the laser beam for forming the pits or marks recorded on the recording medium, the extending direction of the pits or marks Abort the second reproduced signal processing means for reproducing the identification data for copyright protection of the main data due to changes in the pits or marks in a direction perpendicular, the processing of the main data based on the identification data And a reproduction data processing means to be provided.

Further, in the invention according to claim 8, in the information recording medium in which pits or marks are formed on the information recording surface with reference to a predetermined basic period, main data is recorded according to the length and interval of the pits or marks. The identification data for copyright protection of the main data, which is encrypted with a pseudo-random number that is initialized and repeatedly generated at regular physical intervals on the recording medium, is used for the main data recording The beam is controlled so as to be superimposed and recorded by the change of the pit or mark in the direction orthogonal to the extending direction of the pit or mark .

Create the pit row or mark row of pit length and space length or mark length and space length according to the modulation signal, and orthogonal to the pit or mark extension direction with respect to the pit or mark of the pit row or mark row If the change corresponding to the encrypted identification data is given in the direction of the recording, the main data is recorded by the length and interval of the pits or marks, and in addition, the identification is made by the change in the width direction of the pits or marks. Data can be recorded. On the other hand, when the pit shape or the like is physically copied, it is difficult to correctly copy the pit width or the like, thereby making it difficult to correctly reproduce the main data and the identification data. Therefore, the reproduction medium can be excluded on the reproduction side based on the identification data. Further, it is difficult to copy the identification data depending on the recording device that records data according to the length and interval of the pits, so that copying by this type of recording device can be eliminated on the reproduction side.

Therefore it applied to the information reproducing apparatus, together with the reproduced data, by calculation using the pseudo-random number to play identification data, to stop the process in the main playback data by the identification data as a reference, eliminating illegal copy can do.

For this reason, in the information recording medium, the main data is recorded by the length and interval of the pits or marks, and the identification data is recorded by the change in the width direction of the pits or marks to effectively avoid illegal copying. Can do.

  According to the present invention, illegal copying can be effectively avoided.

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

  FIG. 1 is a block diagram showing an optical disc apparatus according to an embodiment of the present invention. The optical disc apparatus 1 records the audio data D1 output from the digital audio tape recorder 3 by exposing the disc master 2 and the sub data necessary for processing the audio data D1. In the manufacturing process of the optical disc, the master disc 2 is developed and then electroformed to produce a mother disc, and a stamper is produced from the mother disc. Further, in the manufacturing process of the optical disk, a disk-shaped substrate is prepared from the stamper thus prepared, and a reflective film and a protective film are formed on the disk-shaped substrate to form a compact disk.

  That is, in this optical disk apparatus 1, the spindle motor 4 rotates the disk master 2 and outputs an FG signal FG whose signal level rises at every predetermined rotation angle from the FG signal generation circuit held at the bottom. The spindle servo circuit 5 drives the spindle motor 4 so that the frequency of the FG signal FG becomes a predetermined frequency in accordance with the exposure position of the disk master 2, thereby rotating the disk master 2 under the condition of a constant linear velocity. To do.

  The recording laser 7 is composed of a gas laser or the like, and emits a laser beam L for exposing a disc master. The optical modulator 8A is composed of an electroacoustic optical element, and switches and outputs the light amount of the laser beam L in accordance with the control signal SC1. Thereby, the optical modulator 8A modulates the light quantity of the laser beam L according to the control signal SC1.

  The optical modulator 8B is composed of an electroacoustic optical element, and emits the laser beam L under on / off control by a modulation signal S1. The mirror 10 bends the optical path of the laser beam L and emits it toward the disc master 2, and the objective lens 11 condenses the reflected light of the mirror 10 on the disc master 2. The mirror 10 and the objective lens 11 are sequentially moved in the outer circumferential direction of the disk master 2 in synchronization with the rotation of the disk master 2 by a thread mechanism (not shown), whereby the exposure position by the laser beam L is sequentially shifted to the outer periphery of the disk master 2. Displace in the direction.

  As a result, in this optical disc apparatus 1, a spiral track is formed by the movement of the mirror 10 and the objective lens 11 while the disc master 2 is rotationally driven, and pits are sequentially formed on this track corresponding to the modulation signal S1. . Further, at this time, the pit width is changed according to the control signal SC1.

  The identification code generation circuit 12 generates identification data for identifying the compact disc created by the optical disc apparatus 1, and switches the signal level of the control signal SC1 according to the identification data. As a result, the identification code generation circuit 12 intermittently falls the light amount of the laser beam L output from the modulator 8A from the light amount of 100 [%] to the light amount of 85 [%], and the pits formed on the disc master 2 The width is modulated according to the identification data.

  The modulation circuit 14 receives the audio data D1 output from the digital audio tape recorder 3, and adds the corresponding subcode data to the audio data D1. Further, the modulation circuit 14 performs data processing on the audio data D1 and the subcode data according to the format of the compact disc, and generates a modulation signal S2. That is, the modulation circuit 14 adds an error correction code to the audio data D1 and the subcode data, and then performs interleaving processing and EFM modulation processing. As a result, the modulation circuit 14 outputs an EFM modulation signal S2 whose signal level changes in a cycle (cycles 3T to 11T) that is an integral multiple of the basic cycle T with respect to the basic cycle T of pit formation.

  The edge position correction circuits 15A and 15B detect the change pattern of the EFM modulation signal S2, and correct the timing of the EFM modulation signal S2 so as to reduce the intersymbol interference during reproduction according to the change pattern. Modulation signals S1A and S1B, which are correction results, are output. At this time, the edge position correction circuit 15A outputs a modulation signal S1A corresponding to the laser beam L having a light quantity of 100 [%] output from the optical modulator 8A, whereas the edge position correction circuit 15B is provided with the optical modulator 8A. The modulation signal S1B corresponding to the laser beam L having a light amount of 85 [%] is output.

  That is, when the light amount of the laser beam L is switched from the light amount of 100 [%] to the light amount of 85 [%] in this way and the pit width is modulated, the signal level of the reproduction signal changes accordingly. Specifically, the amplitudes W1 and W2 of the reproduction signal RF change as shown by the eye pattern of the reproduction signal RF in FIGS. 2 and 3 when the light amount is 100 [%] and 85 [%], respectively. To do.

  When this is observed as a continuous waveform, as shown in FIG. 4, the slice levels SL1 and SL2 for correctly binarizing the reproduction signal are based on the light amount of 100 [%] and the light amount of 85 [%]. It becomes different from the case. That is, the asymmetry changes greatly between the portion with the light amount of 100 [%] and the portion with the light amount of 85 [%].

  As a result, when the reproduction signal RF is binarized at a constant slice level SL1 when the light quantity is 100%, it is difficult to generate a binarized signal at the correct timing (that is, timing synchronized with the basic period T). As a result, a large jitter occurs in the reproduction clock, which makes it difficult to correctly reproduce the audio data recorded on the compact disc. Further, when the reproduction signal with the light amount of 85 [%] is sliced with the slice level SL1 set for the light amount of 100 [%], for example, when the amplitude of the reproduction signal is small, such as a reproduction signal with a period of 3T, 2 The signal level of the binarized signal itself does not cross the slice level SL1, thereby not only increasing the jitter but also causing many bit errors in the reproduction data generated from the binarized signal.

  A general compact disc player has a slice level automatic adjustment circuit that corrects the slice level in response to such a change in asymmetry, but it is difficult to cope with a sudden change in the amount of light. A very long burst error occurs immediately after the light amount of the beam L is switched.

  For this reason, in the optical disk apparatus 1, the edge position correction circuits 15A and 15B correct the pit length formed on the disk master 2, and in the reproduction signal RF with the light amount of 100 [%] and 85 [%], respectively, FIG. As shown in FIG. 5, the modulated signals S1A and S1B obtained by correcting the timing of the modulated signal S2 are output so that the reproduced signal is binarized at the same slice level and the binarized signal can be generated at the correct timing.

  Further, at this time, a change pattern of the EFM modulation signal S2 is detected, and the modulation signals S1A and S1B are output so as to reduce intersymbol interference from adjacent codes according to the change pattern.

  That is, if the light quantity of the laser beam L changes, the degree of intersymbol interference for each light quantity also changes due to the change in the pit width. Therefore, the edge position correction circuits 15A and 15B correct the timing of the modulation signal S2 so that the jitter of the reproduction signal RF due to intersymbol interference is reduced at each light amount.

  The data selector 13 selectively outputs the corresponding modulation signals S1A and S1B in conjunction with the switching of the light quantity of the laser beam L based on the control signal SC1 output from the identification code generation circuit 12.

  FIG. 6 is a block diagram showing the identification code generation circuit 12. In the identification code generation circuit 12, the oscillator 18 generates an identification code clock whose signal level is switched at a sufficiently long period (several hundred to several thousand pit periods) compared to the pit formation period. The N-ary counter 19 is a ring counter that counts the identification code clock, and outputs a count value CT1, and outputs a reset signal RST when the count value is completed.

  The identification data table 20 is composed of a read-on memory circuit that holds bit information, and outputs the held data with the count value CT1 as an address input. As a result, the identification data table 20 sequentially and cyclically outputs bit pattern information used as a synchronization signal, bit information, ID information recorded on the disc master 2, and information about the manufacturing factory.

  The scramble circuit 21 inputs the bit information output from the identification data table 20 to an adder circuit 23 having an exclusive OR circuit configuration, and encrypts the bit information with the M-sequence code output from the M-sequence generator 22 and outputs the encrypted information. . Here, the M-sequence generation circuit 22 includes a plurality of flip-flops and an exclusive OR circuit, and resets the M-sequence code with reference to the reset signal RST. As a result, the scramble circuit 21 outputs a control signal SC1 in which the bit value changes sequentially and cyclically corresponding to the bit information sequentially and cyclically output from the identification data table 20. Note that the M-sequence generation circuit 22 stops outputting the M-sequence code for a predetermined period after the reset signal RST is output. As a result, the bit information output from the identification data table 20 includes the synchronization signal portion. The scramble process is not performed.

  Thus, in this optical disk apparatus 1, the light quantity of the laser beam L is switched from the light quantity of 100 [%] to the light quantity of 85 [%] in accordance with the control signal SC1, so that the M-sequence code is used according to the pit width of the compact disk. Encrypted ID information and the like are recorded together with the synchronization signal.

  FIG. 7 is a block diagram showing the edge position correction circuit 15A. The edge position correction circuit 15B is the same as the edge position correction circuit 15A except that the correction data stored in the rising edge correction circuits 25A and 25B is different, so that the duplicated description is omitted.

  In the edge position correction circuit 15A, the level conversion circuit 26 corrects the signal level of the EFM modulation signal S2 with an output amplitude of 1 [V] to a TTL level with an output amplitude of 5 [V], and outputs it. As shown in FIG. 8, the PLL circuit 27 generates and outputs a clock CK (FIG. 8B) from the modulation signal S3 output from the level conversion circuit 26 (FIG. 8A). Accordingly, in the modulation signal S2, the signal level changes in a cycle that is an integral multiple of the basic cycle T, so that the PLL circuit 27 causes the clock CK whose signal level changes in the basic cycle T synchronized with the modulation signal S2. Is generated.

  As shown in FIG. 9, the rising edge correction circuit 25A connects thirteen latch circuits 28A to 28M operating in response to the clock CK in series, and inputs the output signal S3 of the level conversion circuit 26 to this series circuit. Thus, the rising edge correction circuit 25A samples the output signal S3 of the level conversion circuit 26 at the timing of the clock CK, and detects the change pattern of the modulation signal S2 from the sampling results of 13 consecutive points. That is, for example, when a latch output of “0001111000001” is obtained, it can be determined that the pattern is a change pattern in which a pit having a length of 4T continues after a space having a length of 5T. Similarly, when a latch output of “0011111000001” is obtained, it can be determined as a change pattern in which a pit having a length of 5T continues after a space having a length of 5T.

  The correction value table 29 is formed of a read-only memory storing a plurality of correction data, and outputs correction value data DF corresponding to the change pattern of the modulation signal S3 with the latch outputs of the latch circuits 28A to 28M as addresses. The monostable multivibrator (MM) 30 receives latch outputs from 13 central latch circuits 28G connected in series, and is based on the rising timing of the latch outputs for a predetermined period (fully more than the period 3T). For a short period of time, a rising pulse signal whose signal level rises is output.

  The delay circuit 31 has twelve stages of tap outputs, and the delay time difference between the taps is set to the resolution of the timing correction of the modulation signal in the edge position correction circuit 15A. The delay circuit 31 sequentially delays the rising pulse signal output from the monostable multivibrator 30 and outputs it from each tap. The selector 33 selects and outputs the tap output of the delay circuit 31 according to the correction value data DF, and thereby selects and outputs the rising pulse signal SS (FIG. 8D) having a delay time changed according to the correction value data DF. To do.

  As a result, the rising edge correction circuit 25A rises in response to the rising of the signal level of the modulation signal S2, and the delay times Δr (3, 3) and Δr (4, 3) of the rising edges with respect to the modulation signal S2. , Δr (3, 4), Δr (5, 3),... Generate a rising edge signal SS that changes according to the change pattern of the modulation signal S2.

  In FIG. 8, the change pattern of the modulation signal S2 is represented by a pit length p in units of one cycle of a clock (that is, a channel clock) CK and a pit interval b, and a delay time with respect to a rising edge is represented by Δr. This is indicated by (p, b). Accordingly, in FIG. 8D, the delay time Δr (4, 3) described second is a delay time when there is a blank of 3 clocks before a pit of 4 clocks in length. As a result, the correction value table 29 stores correction value data DF corresponding to all combinations of p and b.

  Accordingly, in the optical disk, the rising edge correction circuit 25A forms a range of the period 12T in units of the basic period T on the optical disk by irradiating the laser beam L according to the modulation signal S2 to form pits. A pit pattern to be detected is detected, and a rising edge signal SS is generated in accordance with this pattern.

  The falling edge correction circuit 25B is the same as the rising edge correction circuit 25A except that the monostable multivibrator 30 operates based on the falling edge of the latch output and the content of the correction value table 29 is different. Composed.

  As a result, the falling edge correction circuit 25B rises in response to the fall of the signal level of the modulation signal S2, and the delay times Δf (3, 3), Δf (4, 4) of the rising edges with respect to the modulation signal S2. 4), Δf (3, 3), Δf (5, 4),... Generate a falling edge signal SR (FIG. 8C) that changes according to the change pattern of the modulation signal S2. In FIG. 8, similarly to the delay time with respect to the rising edge, the delay time with respect to the falling edge is represented by Δf (p, b) by the pit length p and the pit interval b.

  Accordingly, the falling edge correction circuit 25B also detects the pit pattern formed on the optical disk in the range of the period 12T with the basic period T as a unit, and at the timing of ending the irradiation of the laser beam according to this pattern. The falling edge signal SR is generated by correcting the falling edge timing of the modulation signal S2.

  The flip-flop (F / F) 35 (FIG. 7) synthesizes and outputs the rising edge signal SS and the falling edge signal SR. That is, the flip-flop 35 inputs the rising edge signal SS and the falling edge signal SR to the set terminal S and the reset terminal R, respectively, so that the signal level rises at the rising edge of the rising edge signal SS and then falls. A modulation signal S5 whose signal level falls at the rise of the signal level of the edge signal SR is generated. The level inverse conversion circuit 36 corrects the signal level of the modulation signal S5 whose output amplitude is the TTL level, and outputs the corrected signal with the original output amplitude.

  As a result, in the modulation signal S2, the timing of the rising edge and the falling edge is corrected according to the lengths of the front and rear pits and lands, and the laser beam L is applied to the disk master 2 correspondingly. The timing of the correction is also corrected in accordance with the lengths of the front and rear pits and lands.

  As a result, the optical disc apparatus 1 corrects the positions of the front edge and the rear edge of each pit so as to reduce jitter generated by intersymbol interference during reproduction. Further, even when the light amount of the laser beam L is raised by correcting the positions of the front edge and the rear edge by the edge position correction circuits 15A and 15B corresponding to the light amount of the recording laser beam L, the reproduction signal is kept constant. The position of the front edge and the rear edge of each pit is corrected so that the data D1 recorded by the pit length and the pit interval can be reliably reproduced.

  That is, when the light amount of the laser beam L is 100 [%], the positions of the front edge and the rear edge are corrected by the modulation signal S1A output from the edge position correction circuit 15A, and thereby correctly binary at a fixed slice level. When the light quantity of the laser beam L is 85 [%], the positions of the front edge and the rear edge are corrected by the modulation signal S1B output from the edge position correction circuit 15B. %] So that the binarized signal can be generated correctly at the same slice level.

  FIG. 10 is a process diagram for explaining the generation of the correction value table 29 used for edge timing correction in this way. In the optical disc apparatus 1, by appropriately setting the correction value table 29, even when the light amount of the laser beam L, the pit length, and the front and rear blank lengths change, a predetermined slice level is set at a correct timing synchronized with the clock CK. Ensure that the playback signal crosses.

  The correction value table 29 is set in the rising edge correction circuit 25A and the falling edge correction circuit 25B in each of the edge position correction circuits 15A and 15B. However, the generation method is the same except for the generation conditions. Here, the rising edge correction circuit 25A will be described here.

  In this step, a disc master for evaluation is created by the optical disc apparatus 1, and a correction value table is set based on the reproduction result of the compact disc created from this disc master.

  Here, at the time of creating the evaluation master disc, an evaluation standard correction value table 29 is set in the optical disc apparatus 1. The correction value table 29 for evaluation criteria is formed by setting the correction value data DF so that the selector 33 (FIG. 9) always selects and outputs the center tap output of the delay circuit 31. Thus, in this process, the master disc 2 is formed under the same conditions as when the optical modulator 8B is directly driven by the EFM modulation signal S3 with the laser output of 100 [%], that is, under the same conditions as in the normal compact disc production process. Exposure.

  In this step, the exposed master disk 2 is developed and electroformed to create a mother disk, and a stamper 40 is formed from the mother disk. Further, a compact disc 41 is produced from this stamper 40 in the same manner as in a normal compact disc producing process.

  The compact disc player (CD player) 42 reproduces the evaluation compact disc 41 created in this way. At this time, the compact disc player 42 switches its operation under the control of the computer 44, and a reproduction signal RF whose signal level changes according to the amount of return light obtained from the compact disc 41 is sent from the built-in signal processing circuit to the digital oscilloscope 45. Output. Accordingly, the compact disc 41 has a pit width that changes with the switching of the light amount of the laser beam L. When the reproduction signal RF is observed with the digital oscilloscope 45, the reproduction signal is reproduced at a portion corresponding to the pit. Observed with changing amplitude.

  Further, since the front edge and the rear edge of the pit change with the change of the pit width, a large jitter is observed with the change of the amplitude, and the asymmetry changes greatly. Further, even in a portion where pits are formed by a low-level laser beam such as a user area, jitter due to intersymbol interference from the front and rear pits is observed.

  The digital oscilloscope 45 switches the operation under the control of the computer 44, performs an analog-digital conversion process on the reproduction signal RF at a sampling frequency 20 times the channel clock, and outputs the resulting digital signal to the computer 44.

  The computer 44 controls the operation of the digital oscilloscope 45 and processes the digital signal output from the digital oscilloscope 45, thereby sequentially calculating the correction value data DF. Further, the computer 44 drives the ROM writer 46 to sequentially store the calculated correction value data DF in the read-only memory, thereby forming the correction value table 29. In this step, the optical disk is finally manufactured by the correction value table 29.

  FIG. 10 is a flowchart showing a processing procedure in the computer 44. In this processing procedure, the computer 44 proceeds from step SP1 to step SP2, and sets the jitter detection result Δr (p, b) and the jitter measurement count n (p, b) to the value 0. Here, the computer 44 calculates the jitter detection result Δr (p, b) for each combination of the pit length p and the pit interval b before and after the edge to be detected by jitter, and the jitter measurement count n (p, b). ). Therefore, in step SP2, the computer 44 sets all these jitter detection results Δr (p, b) and the number of jitter measurements n (p, b) to initial values.

  Subsequently, the computer 44 proceeds to step SP3, and compares the digital signal output from the digital oscilloscope 45 with a predetermined slice level to generate a digital binarized signal obtained by binarizing the reproduction signal RF. In this process, the computer 44 binarizes the digital signal so that the value above the slice level is 1 and the value 0 is below the slice level.

  Subsequently, the computer 44 proceeds to step SP4, and generates a reproduction clock from the binarized signal composed of this digital signal. Here, the computer 44 simulates the operation of the PLL circuit by arithmetic processing based on the binarized signal, and thereby generates a reproduction clock.

  Further, in the subsequent step SP5, the computer 44 samples the binarized signal at the timing of each falling edge of the reproduction clock generated in this way, and decodes the modulated signal (hereinafter, this decoded modulated signal is decoded). Called the decoded signal).

  Subsequently, the computer 44 proceeds to step SP6 to detect a time difference e from the time point of the rising edge of the binarized signal to the time point of falling edge of the reproduction clock closest to this edge, and thereby jitter at this edge. Time measurement. Subsequently, in step SP7, the computer 44 detects the pit length p and the pit interval b before and after the decoded signal for the edge timed in step SP6.

  Subsequently, in step SP8, the computer 44 adds the time difference e detected in step SP6 to the jitter detection result Δr (p, b) corresponding to the pit length p and the pit interval b before and after, and the corresponding jitter. The measurement number n (p, b) is incremented by a value 1. Subsequently, the computer 44 proceeds to step SP9, determines whether or not the time measurement has been completed for all the rising edges, and returns a step SP5 when a negative result is obtained.

  As a result, the computer 44 repeats the processing procedure of steps SP5-SP6-SP7-SP8-SP9-SP5, cumulatively adds the time-measured jitter detection results for each change pattern appearing in the reproduction signal RF, and counts the number of additions. To do. This change pattern corresponds to a period of 6 samples before and after the reference period T from the edge of the jitter detection target so as to correspond to the number of stages of the latch circuits 28A to 28M in the rising edge correction circuit 25A (a period of 12T as a whole). ).

  When the jitter time measurement is completed for all the edges in this way, the computer 44 moves to step SP10 when an affirmative result is obtained in step SP9, and here, for each change pattern appearing in the reproduction signal RF, the time is increased. Average the measured jitter detection results. That is, since the jitter detected in step SP6 is affected by noise, the computer 44 averages the jitter detection results in this way, and improves the jitter measurement accuracy.

  After averaging the jitter detection results in this way, the computer 44 proceeds to step SP11. Based on the detection results, the computer 44 generates correction value data DF for each change pattern, and stores each correction value data DF in the ROM. Output to writer 46. Here, the correction value data DF is calculated by executing a calculation process of the following equation, where τ is a delay time difference between taps in the delay circuit 31.

  Here, Hr1 (p, b) is a tap of the delay circuit 31 selected by the correction value data DF, and a value of 0 is a center tap. Hr0 (p, b) is a tap of the delay circuit 31 selected by the correction value data DF which is an initial value. In this embodiment, Hr0 (p, b) is set to a value of 0. become. A is a constant. In this embodiment, a is set to a value of 1 or less (for example, 0.7), so that the correction value data is surely converged even if there is an influence of noise or the like.

  The computer 44 uses the correction value data described above when the light amount of the laser beam L is raised and when the light amount is normal, based on the signal level of the reproduction signal RF detected via the digital oscilloscope 45. Even when the generation process is executed and the light quantity of the laser beam L is raised, the reproduction signal RF is binarized at the normal slice level, and the correction value data DF is generated so that the binarized signal can be generated at the correct timing. Is generated.

  When the computer 44 stores the correction value data DF thus generated in the ROM writer 46, the computer 44 moves to step SP12 and ends this processing procedure. Subsequently, the computer 44 executes the same processing procedure for the falling edge of the digital binarized signal, thereby completing the correction value table 29.

  FIG. 12 is a block diagram showing a compact disc reproducing apparatus manufactured as described above. The compact disc player 50 performs spindle control of the spindle motor M by the servo circuit 51 and irradiates the compact disc H with a laser beam from the optical pickup P in a state where the optical pickup 9 is subjected to tracking control and focus control. Further, the compact disc player 50 receives the return light of the laser beam by the optical pickup P, and generates a reproduction signal RF whose signal level changes according to the amount of the return light.

  The binarization circuit 52 equalizes the waveform of the reproduction signal RF, identifies the signal level based on a predetermined threshold value, and outputs the binarization signal S7. The PLL circuit 53 generates and outputs a reproduction clock (channel clock) CK based on the binarized signal S7.

  Here, the reproduction signal RF is extremely small by correcting the timing of the laser beam irradiation in accordance with various pit formation patterns and correcting the timing of the front edge and the rear edge of each pit in the optical disc apparatus 1. Reproduced by jitter. Further, the amplitude is intermittently increased by intermittently raising the light quantity of the laser beam and modulating the pit width. In addition, the timing of laser beam irradiation is corrected in response to changes in the pit width, and the timing of the front and rear edges of each pit is corrected even in the part where the light amount of the laser beam is lowered in this way. Is reproduced by asymmetry equal to other parts.

  As a result, the binarization circuit 52 generates the binarization signal S7 at the correct timing corresponding to the basic period T at the time of recording, and the PLL circuit 53 generates the reproduction clock CK with extremely low jitter. Will be output.

  The EFM demodulation circuit 54 generates reproduction data by sequentially latching the binarized signal with reference to the reproduction clock CK. Further, the EFM demodulation circuit 54 demodulates and outputs the reproduction data. The ECC circuit 55 deinterleaves the reproduction data output from the EFM demodulator circuit 54, and then outputs the error corrected data.

  The identification code detection circuit 56 detects identification data from the amplitude of the reproduction signal RF and outputs it to the system control circuit 77. That is, as shown in FIG. 13, the identification code detection circuit 56 detects pits having the period 6T to the period 11T in the pit detection circuit 57. Here, as shown in FIG. 14, the pit detection circuit 57 inputs the binarized signal S7 to 10 stages of latch circuits 57A to 57J connected in series, and sequentially transfers the binarized signal S7 by the reproduction clock CK. . In the AND circuits 58A to 58F, a predetermined input terminal is set as an inverting input terminal, and latch outputs of the latch circuits 57A to 57J are input, and latch circuits 57A corresponding to the pits of the periods 6T, 7T, 8T,. When the latch output of .about.57J is set to value 1 or value 0, the logic level of the output signal is raised. The OR circuit 59 receives the output signals of the AND circuits 58A to 58F and outputs the logical sum signal. Thereby, the pit detection circuit 57 detects a pit having a long pit length in which the light amount of the laser beam at the time of pit formation is accurately reflected in the amplitude.

  In the identification code detection circuit 56 (FIG. 13), an analog / digital conversion circuit (A / D) AD performs an analog-digital conversion process on the reproduction signal RF and outputs a digital reproduction signal DRF. The delay circuit 61 delays the digital reproduction signal DRF and outputs it at a timing corresponding to the timing of the pit detection in the pit detection circuit 57.

  The latch circuit R latches the digital reproduction signal DRF based on the detection result of the pit detection circuit 57, and thereby the amplitude of the reproduction signal RF is obtained at a timing at which return light is obtained from almost the center of each pit with a period of 6T or more. Is detected. The digital / analog conversion circuit DA performs a digital / analog conversion process on the latch result of the latch circuit R and outputs the result. The binarization circuit 60 binarizes the output signal of the digital / analog conversion circuit DA to generate a binarized signal.

  The PLL circuit 61 detects the reproduction clock from this binarized signal. The synchronization detection circuit 62 detects and outputs the timing of the synchronization signal added by the identification code generation circuit 12 of the optical disc apparatus 1 by monitoring the signal level of the binarized signal. The M-sequence generation circuit 63 sequentially resets the M-sequence code after being reset at the timing detected by the synchronization detection circuit 62. The inverse scramble circuit 64 performs logical operation processing on the M-sequence code and the binarized signal by the adder circuit 65 having an exclusive OR circuit configuration, thereby demodulating the identification data DC1.

  The system control circuit 77 (FIG. 12) is constituted by a computer that controls the overall operation of the compact disc player 50, and determines whether or not the identification data is correctly detected by the identification code detection circuit 56, and here, a negative result is obtained. If it is, the operation of the digital-analog conversion circuit 79 is controlled to stop. Here, the digital-analog conversion circuit 79 performs digital-analog conversion processing on the audio data output from the ECC circuit 55 under the control of the system control circuit 77, and outputs an audio signal SA that is an analog signal.

  In the above configuration, in the optical disc apparatus 1 (FIGS. 1 and 9), the correction value table 29 in the edge position correction circuits 15A and 15B is set to the initial value, and the same conditions as the conventional compact disc creation conditions are set. An evaluation disc master 2 is created, and an evaluation compact disc 41 is created from the disc master 2 (FIG. 10).

  In this compact disk 41 for evaluation, the laser beam L is controlled to be turned on and off by a modulation signal whose signal level changes at a period that is an integral multiple of the basic period T, and the master disk 2 is sequentially exposed. Audio data D1 and the like are recorded. Further, the light quantity of the laser beam L is lowered based on the identification data, and the identification data is recorded by the change of the pit width. Further, the pit length is changed with the change of the pit width.

  As a result, in the reproduced signal obtained from the evaluation compact disc 41, jitter is observed due to intersymbol interference between adjacent pits in a portion where pits are formed with a constant light quantity. Further, in a portion where the pit width changes, a large jitter occurs due to a change in the pit length in addition to the intersymbol interference between adjacent pits. In addition, in the portion where the pit width changes, the amplitude of the reproduction signal changes greatly, and the asymmetry also changes drastically.

  Accordingly, the reproduction signal obtained from the compact disc 41 changes the timing crossing the slice level in accordance with the modulation signal change pattern corresponding to the shape of the front and rear pits and lands and the amount of laser beam at the time of exposure. A large jitter occurs in the recovered clock generated more.

  The compact disc 41 is reproduced by a compact disc player 42, and a reproduction signal RF is converted into a digital signal by a digital oscilloscope 45, and then a binary signal, an EFM decoded signal, and a reproduction clock are generated by a computer 44. Further, the compact disc 41 detects the pits and lands before and after the decoded signal for each edge of the binarized signal and detects the change pattern of the modulation signal. The jitter of each edge with respect to the reproduction clock is detected for each change pattern. The amount is timed.

  Furthermore, the time measurement results are averaged for each change pattern when the laser beam power is started up and held at a constant value, and the jitter amount due to each laser beam light amount is the jitter due to intersymbol interference. It is detected for each change pattern together with the quantity. The compact disk 41 performs the arithmetic processing of the expression (1) based on the delay time difference τ between taps of the delay circuit 31 (FIG. 9) based on the jitter amount thus detected, and the center tap of the delay circuit 31 is The tap position of the delay circuit 31 that can cancel out the detected jitter amount is detected as a reference. Further, in the compact disc 41, data for specifying the detected tap position is stored in the read-only memory as correction value data DF, whereby the delay time difference τ between taps of the delay circuit 31 is set as a jitter correction unit, and the correction value is set. A table 29 is formed.

  At this time, correction value data DF corresponding to the laser beam quantity of 100 [%] is recorded in the correction value table 29 of the edge position correction circuit 15A, and correction value data DF corresponding to the laser beam quantity of 85 [%] is recorded. Are recorded in the correction value table 29 of the edge position correction circuit 15B.

  When the correction value table 29 is formed in this way, in the optical disc apparatus 1, the audio data D1 is subjected to predetermined data processing and converted into a modulation signal S2 whose signal level changes in units of the basic period T. The modulated signal S2 is converted into a TTL level in the edge position correction circuit 15A (FIG. 7), and then the clock CK is reproduced by the PLL circuit 27. In each of the rising edge correction circuit 25A and the falling edge correction circuit 25B (FIG. 9), the change patterns are detected by being sequentially latched by the 13-stage latch circuits 28A to 28M.

  Further, the modulation signal S2 is input to the monostable multivibrator 30 from an intermediate latch circuit 28G of the latch circuits 28A to 28M. The rising edge correction circuit 25A has a rising edge timing and a falling edge correction circuit 25B. The output of the monostable multivibrator 30 is triggered at the timing of the falling edge, and the rising pulse signal and the falling pulse signal whose signal level rises at the timing of the rising edge and the falling edge are generated.

  The rising pulse signal and the falling pulse signal are sequentially delayed in units of the delay time τ used for calculating the correction value data DF in the delay circuit 31 of the rising edge correction circuit 25A and the falling edge correction circuit 25B, respectively. The tap output of the delay circuit 31 is output to the selector 33. On the other hand, in the change pattern of the modulation signal S2 detected by the latch circuits 28A to 28M, the corresponding correction value data DF is detected by accessing the correction value table 29 using the latch outputs of the latch circuits 28A to 28M as addresses. The contact of the selector 33 is switched by the correction value data DF.

  Thus, the jitter is corrected when the laser beam L detected by the evaluation compact disc 41 is irradiated with the light amount of 100% by the selector 33 of the rising edge correction circuit 25A and the falling edge correction circuit 25B, respectively. In addition, a rising edge signal SS and a falling edge signal SR obtained by correcting the timing of the rising edge and the falling edge of the modulation signal S2, respectively, are output, and these rising edge signal SS and falling edge signal SR (FIG. 7) are output. Are synthesized by the flip-flop 35.

  Further, the output signal S5 of the flip-flop 35 is subjected to signal level correction by the level inverse conversion circuit 36, and thereby the laser beam L detected by the evaluation compact disc 41 is irradiated with the light amount of 100%. A modulation signal S1A is generated by correcting the timing of the edge of the modulation signal S2 so as to correct jitter, that is, to reduce intersymbol interference.

  Similarly, in the modulation signal S2, a change pattern is detected by the edge position correction circuit 15B, and a rising edge signal SS and a falling edge signal SR are generated by the correction value data DF corresponding to the change pattern, and these rising edges are generated. The signal SS and the falling edge signal SR are combined by the flip-flop 35. As a result, the modulation signal S2 is corrected so as to correct the jitter when the edge position correction circuit 15B irradiates the laser beam L detected by the evaluation compact disc 41 with the light amount of 85 [%], that is, the laser beam light amount. The modulation signal S1B is generated by correcting the timing of the edge of the modulation signal S2 so as to cancel the change in the pit length accompanying the falling and to reduce the intersymbol interference.

  On the other hand, in the optical disc apparatus 1, synchronization signals, identification data, and the like are sequentially and cyclically output from the identification data table 20 (FIG. 6), and these data are encrypted by the M-sequence code in the scramble circuit 21. . Further, the control signal SC1 based on the encrypted identification data or the like is input to the optical modulator 8A (FIG. 1). Thereby, in the optical disc apparatus 1, the light quantity of the laser beam L is switched from the light quantity of 100 [%] to the light quantity of 85 [%] according to the identification data and the identification data is changed by the change of the pit width. Recorded on the master disc 2.

  At this time, the data selector 13 selectively inputs the modulation signals S1A and S1B output from the edge position correction circuits 15A and 15B to the optical modulator 8B in conjunction with the switching of the light quantity. The audio data D1 is recorded according to the pit length and the pit interval, and at this time, the exposure timing is corrected so as to prevent the change in the pit length accompanying the change in the pit width according to the identification data or the like. For each pit, the exposure timing is corrected so as to reduce intersymbol interference caused by adjacent pits.

  When the disc master 2 is exposed in this way, a compact disc H is produced from the disc master 2, and the compact disc H is reproduced by the compact disc player 50 (FIG. 12). In this compact disc H, the positions of the front edge and the rear edge are corrected according to the pattern by the combination with the adjacent pit so that the audio data D1 reduces the intersymbol interference from the adjacent pit, and the pit length and the pit interval are corrected. Will be recorded. Further, the encrypted identification data is recorded by the change of the pit width, and in the audio data D1, the positions of the front edge and the rear edge are corrected so as to cancel the change of the pit length due to the change of the pit width. It will be.

  The compact disc player 50 detects a reproduction signal RF whose signal level changes in accordance with the amount of return light from the compact disc H produced in this way, and the reproduction signal RF is predetermined in the binarization circuit 52. Are sliced at the slice level and converted to a binary signal S7. Further, a reproduction clock CK is generated from the binarized signal S7 in the PLL circuit 53. In the EFM demodulator circuit 54, the binarized signal S7 is sequentially latched by the reproduction clock CK to generate reproduction data, which is demodulated. The Further, the reproduced data is subjected to deinterleaving processing and error correction processing in the subsequent ECC circuit 55, converted into an analog signal and output.

  In this series of processes, in the compact disc H according to this embodiment, the positions of the front edge and the rear edge are corrected so as to cancel the change in the pit length due to the change in the pit width. Thus, the reproduction signal RF can be binarized and a binarized signal can be generated at the correct timing. That is, the binarized signal can be generated so that the jitter of the reproduction clock CK accompanying the switching of the light amount can be effectively avoided. Furthermore, with respect to intersymbol interference, the edge position is corrected so as to reduce this, so that jitter due to intersymbol interference can also be reduced. As a result, the audio data can be correctly reproduced even though the pit width is changed.

  The binarized signal S7 is input to the identification code detection circuit 56 together with the reproduction signal RF and the reproduction clock CK, and the identification data recorded by the change of the pit width is reproduced here. That is, in the identification code detection circuit 56 (FIG. 13), the binarized signal S7 detects the timing of pits having a period of 6T or more in the pit detection circuit 57, and the signal level is detected in the latch circuit R based on this timing. Further, the signal level is determined by the binarization circuit 60, and the encrypted identification data is reproduced. A clock of the identification data is reproduced by the PLL circuit 61, and the encryption is canceled by the M-sequence data with reference to the clock.

  In the compact disc player 50, the system control circuit 77 judges whether or not the identification data has been correctly reproduced, thereby judging whether or not the compact disc H is a legitimate product. The audio signal SA is output from the analog conversion circuit 79, whereas in the case of a copy product, the output of the audio signal SA is stopped.

  That is, it is difficult to record identification data by controlling the pit width for a copy compact disc generated by recording audio data D1 reproduced by this type of compact disc player 50. It becomes difficult to reproduce the identification data. In addition, since the identification data itself is encrypted, it is difficult to easily decode it. As a result, such a copy can be made difficult to reproduce on the compact disc player 50 side and can be removed from the market.

  In addition, when copying a compact disc by physically transferring the pit shape from the compact disc H, which is a regular product, physical changes in the pit shape cannot be avoided, and the corrected edge position and the change in pit width are thereby avoided. It is difficult to accurately reproduce. As a result, a compact disc using this kind of copy binarizes the reproduction signal RF and the signal level of the binarized signal S7 does not change at the correct timing, and accordingly, jitter occurs in the reproduction clock CK, and further the reproduction data Bit errors that are difficult to correct. This makes it difficult for the compact disc player 50 to reproduce a compact disc by this type of copying.

  In addition, since it is difficult to correctly copy the pit width, it is difficult to detect correct identification data on the compact disc player side, which also makes reproduction difficult.

  According to the above configuration, the audio data D1, which is the main data, is recorded by the pit length and the pit interval, and the identification data of the compact disc is encrypted and recorded by the pit width, so that illegal copies can be reproduced. It can be easily identified on the device side and set to be difficult to reproduce, and this kind of illegal copy can be eliminated.

  At this time, desired data is recorded at a high density by correcting the edge of each pit so as to correct the change in the pit length due to the pit width and further reduce the coding interference caused by the adjacent pits. Even in this case, the audio data can be reliably reproduced and illegal copies can be surely excluded, and this kind of illegal copy can be excluded.

  Furthermore, for pits with a period of 6T or more, by selectively detecting the signal level of the reproduction signal and reproducing the identification data recorded according to the pit width, the change in the signal level of the reproduction signal accompanying the change in the pit width is reliably detected. Thus, the identification data can be correctly reproduced.

  In the above-described embodiment, the case where the identification data is recorded by changing the width of the pit for recording the audio data has been described. However, the present invention is not limited to this. For example, the TOC data is recorded in the lead-in area. The identification data may be recorded by changing the width of the pit.

  Furthermore, in the above-described embodiment, the case where audio data is simply encoded and recorded has been described. However, the present invention is not limited to this, and can also be applied to the case where encrypted audio data or the like is recorded. In this case, the encoded data used for encryption may be recorded together with the pit width.

  In the above-described embodiment, the case where the identification data of the optical disk is recorded by recording the pit width together with the data such as the manufacturing location has been described. However, the present invention is not limited to this, and the identification of each copyrighted work recorded on the compact disk is described. The present invention can be widely applied to the case where data is recorded together or independently, and further to the case where identification data of a manufacturer or the like is recorded together or alone.

  Furthermore, in the above-described embodiment, the case where the signal level of the reproduction signal is detected for pits having a period of 6T or more has been described, but the present invention is not limited to this, and when the change in the pit width can be identified sufficiently in practice, The signal level of the playback signal may be detected for other pits, and conversely, for example, the signal level of the playback signal is detected only for pits with a specific period whose pit width changes significantly due to physical copying. May be.

  In the above-described embodiments, the case where the light amount of the laser beam is switched at a sufficiently long time interval for a continuous pit row has been described. However, the present invention is not limited to this, and the pit width can be changed sufficiently in practice. , The laser beam light quantity may be switched only for specific pits, and thereby the pit width may be modulated by switching the laser beam light quantity for each successive pit, for example.

  Further, in the above-described embodiment, the case where the light amount of the laser beam is switched in two stages to modulate the pit width has been described, but the present invention is not limited to this, and when the change in the pit width can be identified practically, The pit width may be modulated by switching the light quantity of the laser beam in multiple stages.

  In the above-described embodiment, the case where the identification data is repeatedly recorded simply by changing the pit width has been described. Depending on the above, it may be executed only for a predetermined area. In this case, for example, if identification data is recorded by changing the pit width at the timing synchronized with the rotation of the compact disc, a barcode-like pattern that radiates on the reflecting surface of the compact disc is formed as shown in FIG. It is possible to determine with the naked eye whether or not the copy is illegal based on the presence or absence of this pattern. A pattern such as a manufacturer name can also be formed on the reflective surface.

  Furthermore, in the above-described embodiment, the case where it is determined whether or not the illegal copy is made based on whether or not the identification data has been correctly reproduced has been described. However, the present invention is not limited to this. It may be judged whether the copy is illegal or not by collating with other identification data recorded in the area, and the identification data encrypted with other series of encoded data is recorded by the pit width separately. Various determination methods based on the identification data can be widely applied, for example, when determining whether or not the copy is illegal.

  In the above-described embodiments, the case where an optical disc is created by directly using a correction value table created from an evaluation optical disc has been described. However, the present invention is not limited to this, and a correction value created from an evaluation optical disc. An evaluation optical disk may be newly created using the table, and the correction value table may be corrected by the newly created evaluation optical disk. If the correction value table is corrected repeatedly in this way, the jitter can be reliably reduced accordingly.

  In the above-described embodiments, the case where the modulation pattern is sampled 13 times to detect the change pattern has been described. However, the present invention is not limited to this, and the number of samplings may be increased as necessary. It is possible to deal with a recording information pattern.

  Further, in the above-described embodiment, the case where the jitter amount is measured by the time measurement of the binary signal based on the basic clock and the correction value data is generated from the measurement result has been described. However, if sufficient accuracy can be secured in practice, the correction value data may be generated by detecting the signal level of the reproduction signal based on the basic clock, instead of measuring the jitter amount by this time measurement. In this case, an error voltage from the signal level of the detected reproduction signal to the slice level is calculated, and correction value data is calculated from the error voltage and the transient response characteristic of the reproduction signal.

  Further, in the above-described embodiment, the case where the timing of the modulation signal is corrected according to the correction value data tabulated has been described. However, the present invention is not limited to this, and is detected in advance when practically sufficient accuracy can be secured. Instead of the correction value data, the correction value data may be calculated by arithmetic processing, and thereby the timing of the modulation signal may be corrected.

  Furthermore, in the above-described embodiment, the case where correction value data is calculated using an evaluation optical disk has been described. However, the present invention is not limited to this, and for example, when applied to a write-once optical disk apparatus, a so-called test writing area The correction value data may be calculated based on the test writing result at.

  In the above-described embodiments, the case where the present invention is applied to an optical disk has been described. However, the present invention is not limited to this, and an optical disk apparatus that records various data using pits and a thermomagnetic recording technique are applied. Therefore, the present invention can be widely applied to optical disc apparatuses that record various data using marks. Incidentally, the present invention can be widely applied to an optical disk apparatus adapted to record various data in a multi-valued manner due to a difference in transient response characteristics of a reproduction signal.

  The present invention relates to an information recording device, an information reproducing device, and an information recording medium, and can be applied to, for example, a compact disc, its recording device, and a reproducing device.

1 is a block diagram showing an optical disc apparatus according to a first embodiment of the present invention. It is a signal waveform diagram which shows the reproduction | regeneration signal from a pit by the light quantity of a laser beam of 100 [%]. It is a signal waveform diagram which shows the reproduction | regeneration signal from a pit by the light quantity of a laser beam of 85 [%]. It is a signal waveform diagram which shows the change of the slice level by the difference in light quantity. FIG. 5 is a signal waveform diagram showing a reproduction signal by a compact disc produced by the optical disc apparatus of FIG. 1 in comparison with FIG. 4. FIG. 2 is a block diagram showing an identification code generation circuit of the optical disc apparatus of FIG. 1. FIG. 2 is a block diagram showing an edge position correction circuit of the optical disc apparatus of FIG. 1. It is a signal waveform diagram with which it uses for description of operation | movement of the edge position correction circuit of FIG. FIG. 8 is a block diagram illustrating a rising edge correction circuit in the edge position correction circuit of FIG. 7. FIG. 7 is a process diagram illustrating a correction value table creation process in the optical disc apparatus of FIG. 1. It is a flowchart which shows the process sequence of the computer in the process of FIG. It is a block diagram which shows the compact disc player of the compact disc produced with the optical disc apparatus of FIG. It is a block diagram which shows the identification code detection circuit of the compact disc player of FIG. It is a block diagram which shows the pit detection circuit of the identification code detection circuit of FIG. It is a top view which shows the compact disk which concerns on another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical disk apparatus, 2 ... Disc master, 8A, 8B ... Optical modulator, 12 ... Identification code generation circuit, 13 ... Data selector, 15A, 15B ... Edge position correction circuit, 21 ... Scramble circuit , 29... Correction value table, 41, H... Compact disc, 42, 50... Compact disc player, 44 ... computer, 56... Identification code detection circuit, 57. circuit

Claims (8)

Information for recording main data by irradiating a recording medium with a laser beam and forming a pit row or mark row on the recording medium with a pit length and space length based on a predetermined modulation signal, or with a mark length and space length In the recording device,
Modulation signal generation means for generating the modulation signal based on the main data;
A pseudo-random number generating means for initializing at a regular physical interval on the recording medium and repeatedly generating pseudo-random numbers;
Encrypted identification data generating means for generating encrypted identification data by encrypting identification data for copyright protection of the main data using the pseudo random number;
The control of the laser beam creates the pit row or mark row of the pit length and space length or mark length and space length according to the modulation signal, and the pit row or mark row for the pit or mark of the pit row or mark row An information recording apparatus comprising: a laser beam control unit that applies a change corresponding to the encrypted identification data in a direction orthogonal to the extending direction of the pits or marks . The modulation signal generating means includes
When the reproduced signal obtained from the recording medium is binarized at a predetermined slice level to generate a binarized signal, the modulation signal is changed so that the binarized signal changes based on a predetermined basic period. The information recording apparatus according to claim 1, further comprising a timing correction unit that corrects the timing. The timing correction means includes
The information recording apparatus according to claim 2, wherein the timing of the modulation signal is corrected according to a change pattern of the modulation signal. The timing correction means includes
According to the correction data stored in the correction data storage means, correct the timing of the modulation signal,
The correction data is
The information recording apparatus according to claim 2, wherein the information recording apparatus is set based on a reproduction result of the evaluation recording medium. The recording medium is
An optical disc,
The information recording device includes:
Rotating and driving the optical disc, sequentially forming the pits or marks,
The information recording apparatus according to claim 1, wherein the identification data is repeated in synchronization with rotation of the optical disc, and the laser beam is controlled by the laser beam control unit. The information recording apparatus according to claim 1, wherein the recording medium is a master disc used for manufacturing an optical disc. In the information reproducing apparatus for reproducing the data recorded on the recording medium based on the return light obtained by irradiating the recording medium with the laser beam,
A reproduction optical system that receives the return light and outputs a reproduction signal whose signal level changes according to pits or marks formed on the recording medium;
First reproduction processing means for processing the reproduction signal and outputting main data recorded by the length of the pit and space or the length of the mark and space;
A pseudo-random number generating means for initializing at a regular physical interval on the recording medium and repeatedly generating pseudo-random numbers;
Changes in the pits or marks in a direction perpendicular to the extension direction of the pits or marks recorded on the recording medium by controlling the laser beam that forms the pits or marks by processing the reproduction signal with the pseudo-random numbers Second reproduction signal processing means for reproducing identification data for copyright protection of the main data by
Reproduction data processing means for stopping the processing of the main data based on the identification data. In an information recording medium in which pits or marks are formed on the information recording surface based on a predetermined basic period,
The main data is recorded by the pseudo-random number that is repeatedly generated by initializing at the physical constant interval on the recording medium while the main data is recorded by the length and interval of the pit or mark. the copyright identification data for protection were recorded superimposed by a change in the pits or marks in the direction orthogonal to the extending direction of the pits or marks by controlling the laser beam to be recorded in the main data An information recording medium characterized by the above.

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