JP4407293B2 - Disc playback control method and disc playback apparatus - Google Patents

Description

The present invention relates to a disc playback control method and a disc playback apparatus.

  In recent years, CDs and DVDs that recorded content such as still images, videos, and music have become widespread, and the act of illegally duplicating (piracy) and selling them has been infringed, infringing copyright. Or damaging the disc manufacturer / distributor has become a social problem.

  Various attempts have been made to prevent damage caused by pirated copies, and one of them is to prevent pirated discs from being detected and played back by the disc player. The method for detecting this pirated disk is, for example, that the signal position of a disk stamped at a factory is encrypted and recorded on the magnetic layer, and the disk manufactured by dubbing shifts in this position (angle). There is a method used for detection of this (see, for example, Patent Document 1).

  In order to carry out this pirated copy detection method, the signal position of the disk is measured when the disk is reproduced, and the measured signal position is compared with the signal position recorded in advance on the disk. It is determined whether or not there is a discrepancy, and if there is a discrepancy, this disc is determined as a pirated version.

  For this purpose, the fact that the rotation pulse of the motor and the index signal of the optical sensor are generated once per fixed rotation of the disk is used to divide the interval into, for example, six divided zones, thereby obtaining the signal position time slot Z1. ~ Z6 is defined. On the other hand, the address signal obtained from the subcode of the reproduction signal is measured in which of the signal position time slots Z1 to Z6, and the address signal indicated by the measured correspondence and the previously recorded signal position is measured. And the corresponding relationship between the time slots Z1 to Z6, and if the corresponding relationship does not match, the reproduction disc is detected as a pirated version. In this case, obtaining the signal position time slots Z1 to Z6 from the generation timing of the index signal corresponds to detecting the angle of the disk (more precisely, the angle range).

  In addition, in the case of a two-layer disc in which the recording capacity is increased by recording content data on two layers, both layers are bonded together when manufacturing a two-layer disc. Adhering properly without adjusting the angle between the layers. For this reason, the angle between the two layers is a random value and is different for each disk. Therefore, when such a two-layer disc is illegally forged, the angle between the two layers is different from that of the original disc.

  Therefore, a value obtained by actually measuring the angle between these two layers is recorded in a dedicated recording area at the time of manufacture, and the angle between the two layers is detected during reproduction, and this angle and the angle recorded in the dedicated recording area are recorded. It is conceivable that reproduction of the content data on the disc is permitted only when the values match, and if it is not, it is determined that the content data is not a fake and the content data on the disc is not reproduced. Therefore, it is necessary to accurately detect the angle between the two layers of the disk on the reproducing apparatus side.

As a conventional method for detecting the angle of such a disk, there is the following method. In other words, if the disc is eccentric, tracking errors and the like will have a periodicity synchronized with the rotation, so that the error is stored and corrected accordingly in synchronization with the rotational period to achieve higher accuracy. When realizing tracking, it is necessary to detect the disk angle. For this purpose, the rotation angle of the disk is measured by measuring the clock signal using the address signal as the origin signal of the rotation angle (for example, Patent Document 2). reference).
JP-A-8-273164 (pages 11-12, FIGS. 6, 4) JP 2001-195760 (page 15, FIG. 15)

  However, in the former method of detecting the angle of the conventional disk, since it is not necessary to increase the accuracy of the detected angle, a rough angle measuring method is used in which the angle is measured in a range of 6 sections. Angle detection with high accuracy is not possible. In addition, the latter method can obtain highly accurate angle information, but in the case of a disc having two or more layers, information on the relative angle between layers cannot be obtained. Therefore, the conventional method for measuring the relative angle between two layers in a disk having two or more layers is to use an FG (frequency generator) signal of a motor that rotates the disk. In order to increase the accuracy when detecting the relative angle, a highly accurate FG is required. However, since a motor equipped with a high-precision FG is expensive, there is a problem that the cost of the reproducing apparatus becomes high.

The present invention was devised in view of the above circumstances, an object of the present invention, without increasing the cost of the reproducing apparatus, Ki 2 relative angle between the layers of the disk out be accurately detected, the disk It is an object of the present invention to provide a disc playback control method and a disc playback apparatus capable of realizing pirated copy reproduction prevention by disc authenticity determination utilizing the fact that the relative interlayer angle differs from one disc to another.

Since the disc reproduction control method of the present invention to achieve the above object, the steps of rotating the disk recording medium at a constant speed, the first time to read the A data recorded in the A layer of the disk recording medium And a second step of reading out the B data recorded on the B layer of the disk recording medium at a position on the same circumference or in the vicinity of the same circumference from the rotation center of the A data and the disk recording medium . detecting a time, calculating the interlayer relative angle of the a layer and the B layers of the disk recording medium from the difference between the second time and the first time, the from the disk recording medium a A step of reading interlayer relative angle information indicating an interlayer relative angle between the layer and the B layer, and a step of comparing the calculated interlayer relative angle with the read interlayer relative angle information. ; And a flop.

The disc playback apparatus of the present invention is a disc playback apparatus that accesses an optical pickup to a recording location of data recorded on an arbitrary layer of a disc recording medium having a plurality of recording layers, and reads the data. Rotating means for rotating the disk recording medium at a constant speed; and accessing the optical pickup to read A data in the A layer of the disk recording medium; accessing the optical pickup to access the A data and the disk recording medium Read means for reading B data recorded on the B layer of the disc recording medium at a position on the same circumference or in the vicinity of the same circumference from the center of rotation, a time and B for reading A data by the optical pickup A timing means for timing the time b from which data is read, and the disc based on the time difference between the time a and the time b. An interlayer angle detection means for calculating the interlayer relative angle between the A layer and the B layer of the recording medium, the interlayer relative indicating the interlayer relative angle between the A layer and the B layer of the disk recording medium is recorded in advance on the disk recording medium reads the angle information, and comparator means for comparing the interlayer relative angle information read the said calculated interlayer relative angle.

As described above, according to the present invention, the angular difference between the position of the A data recorded on the A layer of the disk recording medium and the position of the B data recorded on the B layer from the disk rotation center is used as the A layer and the B layer. If the relative angle between the A layer and the B layer generated when the disc is manufactured by laminating the discs, the relative angle between the A layer and the B layer is set at a predetermined position of each layer if the rotation of the disc recording medium is constant. Since this corresponds to the difference between the read times of the recorded A data and B data, if the relative angle is calculated and detected from the difference between the read times of the A data and B data, the interlayer angle of the disk recording medium can be determined. It can be detected with high accuracy.

According to the present invention, the rotation of the disk recording medium is made constant, and the A data recorded in the A layer and the position on the same circumference or the vicinity of the same circumference from the rotation center of the A data and the disk recording medium. By calculating and detecting the relative angle between the A layer and the B layer from the read time difference from the B data recorded on the B layer, the relative angle between the two layers of the disc can be accurately determined without increasing the cost of the reproducing apparatus. It can be detected well.
Further, by using the above-described method for detecting the relative angle between the two layers of the disc, the reproduction of the pirated version based on the authenticity determination of the disc 100 using the fact that the relative angle of the first layer and the second layer of the disc 100 is different for each disc. Prevention can be realized inexpensively and easily.

The relative angle between the two layers of the disk is accurately detected without increasing the cost of the reproducing apparatus, and the relative angle between the two layers of the disk is detected by this interlayer angle detection method so that the relative angle between the disks is determined for each disk. For the purpose of realizing inexpensive and easy reproduction prevention of pirated editions by discriminating disc authenticity using the difference, A data recorded on the A layer of the disc recording medium is read and recorded on the B layer of the disc recording medium. And the relative angle between the A layer and the B layer of the disk recording medium is calculated from the difference between the read times of the A data and the B data, and the disc detected by this interlayer angle detection method is used. The relative angle between the two layers is compared with the relative angle between the A layer and the B layer recorded on the disc in advance, It was achieved by controlling the reproduction also playback stop of a content of risk.

  FIG. 1 is a block diagram showing a configuration of a disc reproducing apparatus according to an embodiment of the present invention. The disk reproducing apparatus includes a spindle motor 1 that rotates a disk 100 (a disk having a two-layer structure), a spindle motor control unit 2 that controls the rotation of the spindle motor 1, and an optical pickup (OP) 3 that reads recorded data from the disk 100. The optical pickup control unit 4 that controls the focus and tracking of the optical pickup 3, the sled motor 5 that moves the optical pickup 3 in the radial direction of the disk 100, the sled motor control unit 6 that controls the sled motor 5, and the input from the optical pickup 3 A read processor 7 for processing an RF signal from the signal to be read, a decoding unit 8, an ECC (Error Check and Correct) processing circuit 9 for correcting an error of the reproduction signal in units of error correction blocks, a buffer memory 10 for temporarily holding the reproduction signal, A compression / decompression unit that decompresses and decompresses the playback signal 1. An output circuit 12 that outputs a reproduction signal that has been decompressed and returned to the original data; an angle shift reading unit 13 that reads a relative angle between two layers of the disk 100 by a signal input from the ECC processing circuit 9; An angle reading control unit 14 that performs control for reading the relative angle between the layers, an authenticity determination / output control unit 15 that determines the authenticity of the disc, and controls whether video / audio data is output from the output circuit 12 based on the result. And a system control unit 16 for controlling the entire apparatus.

  Next, the operation of the playback apparatus of this embodiment will be described. In the normal reproduction mode, the spindle motor control unit 2 controls the rotational speed of the spindle motor 1 in the radial position of the optical pickup 3 so as to perform CLV (Constant Linear Velocity) control in which the reading speed is constant regardless of the reading position of the disk 100. Variable control is performed according to. Thereby, the optical pickup 3 always scans the recording track on the disk 100 in the linear direction at the same speed, and reads the recording data at a constant speed.

  The RF signal read by the optical pickup 3 is input to the read processor 7 where binarization of the RF signal, generation of a tracking error signal, a focus error signal, and the like are performed. The binarized RF signal is sent to the decoding unit 8 at the next stage to become EFM (Eight-to-Fourteen-Modulation) decoded digital data, which is error-corrected by the ECC processing circuit 9. The digital data thus error-corrected is input to the compression / decompression unit 11 via the buffer memory 10 and decompressed, becomes the original video / audio data, is input to the output circuit 12, and the video is displayed on a display (not shown). Or, sound is output from headphones or speakers.

  On the other hand, the tracking error signal generated by the read processor 7 is input to the optical pickup control unit 4 and the sled motor control unit 6, and tracking control is performed by the optical pickup control unit 4 and the sled motor control unit 6, and a focus error is also generated. A signal is input to the optical pickup control unit 4, and focus control is performed by the optical pickup control unit 4. The optical pickup control unit 4 also performs focus control for jumping between two layers of the disk 100.

  Here, when the disc 100 is set in the apparatus and the reproduction is started, the relative angle between the two layers of the disc 100 is detected by entering the angle detection mode before reproducing the recording data in the normal mode described above. The authenticity of the disc 100 is determined. This will be described below with reference to the flowchart of FIG.

  First, when the disc 100 is set, the system control unit 16 operates the apparatus in the normal reproduction mode to read and hold the addresses of chapters A and B from a predetermined recording area of the disc 100 (step S1). At this time, the system control unit 16 reads the relative angles of the first and second layers of the disc 100 from a predetermined recording area of the disc 100 and sends them to the authentication / output control unit 15. Hold it.

  Next, the system control unit 16 puts the apparatus into the angle detection mode (step S2). In this angle detection mode, the position control of the optical pickup 3 and the rotation control of the spindle motor 1 are quickly performed by the angle reading control unit 14 under the control of the system control unit 16. In this angle detection mode, the system control unit 16 focuses the laser light output from the optical pickup 3 on the first layer of the disc 100 (step S3), and then starts the chapter A from the chapter A address by the optical pickup 3. The part is read repeatedly (step S4). At that time, it is determined whether or not the head portion of chapter A can be read (step S5). If it cannot be read, the track jump timing is shifted (step S6), and the process returns to step S4.

  When the head portion of chapter A can be read, the system control unit 14 issues a command to the spindle motor control unit 2 via the angle reading control unit 14, and the rotation speed of the spindle motor 1 is read when the head portion of chapter A is read. The speed is fixed (step S7). After that, the reading time of the head part of chapter A is stored (step S8), and then the laser light output from the optical pickup 3 is focused on the second layer of the disc 100 and the reproduction target layer is the second layer. (Step S9), the head part of chapter B is repeatedly read from the address of chapter B (step S10).

At that time, it is determined whether or not the head portion of chapter B can be read (step S11). If it cannot be read, the track jump timing is shifted (step S12), and the process returns to step S10. When the head part of chapter B can be read, the reading time of the head part of chapter B is stored (step S13).

  Next, since the system control unit 16 gives the read time of the first part of chapter A and the read time of the first part of chapter B to the angular deviation reading unit 13, the angular deviation reading unit 13 is a relative angle between the two layers of the disk 100. (Details will be described later) are calculated (step S14). Thereafter, the system control unit 16 returns the apparatus to the normal mode (step S15), and ends the process immediately after setting the disk 100.

  FIG. 3 is a diagram for explaining the details of the processing for calculating the relative angle between the two layers in the angle deviation reading unit 13 described above. FIG. 3 (1) shows the disc 100, where A indicates the leading portion of the first layer of chapter A and B indicates the leading portion of the second layer of chapter B. FIG. C is the rotation center of the disk 100.

  At this time, since the rotational speed of the disk 100 is constant in the process of step S7 described above, the time at which the head portion of chapter A can be read in the process of step S8 is as shown in FIG. It is a plurality of times every 100 rotation periods t. Further, the time at which the head portion of chapter B can be read out in the process of step S13 is as shown in FIG. 3 (3), where p is the delay time corresponding to the angular deviation between chapter A and chapter B. It is a plurality of times every t.

  In this case, if the transition time required until the optical pickup 3 jumps from the first layer to the second layer of the disc 100 and accesses the head portion of the second layer chapter B is 0, the first layer chapter The read time difference between A and chapter B is p. However, in actuality, a transition time is required until the optical pickup 3 jumps from the first layer to the second layer of the disc 100 and accesses the head part of the chapter B of the second layer. Therefore, the time at which the head portion of chapter B can be read is a time shifted by p with respect to the reading time of the head portion of chapter A, as shown in FIG. The data is read at any time shifted. Therefore, if the read time Ta of the head portion of chapter A is t, the read time Tb of the head portion of chapter B is nt + p. However, n is a positive integer determined according to the transition time.

  The time difference D between the reading time Ta at the beginning of chapter A and the reading time Tb at the beginning of chapter B is D = (nt + p) −t. n is indefinite depending on the transition time, but the remainder of D divided by t is p. Thus, the angle difference Θ between the heads of chapter A and chapter B, that is, the relative angle Θ of the first layer and the second layer of the disc 100 can be obtained as Θ = 360 ÷ t × p.

  As described above, when the relative angle Θ of the first layer and the second layer of the disc 100 is obtained by the angular deviation reading unit 13, the angular deviation reading unit 13 sends this relative angle Θ to the authenticity determination / output control unit 15. As a result, the authenticity determination / output control unit 15 compares the detected relative angle Θ of the first layer and the second layer of the disc 100 with the relative angle Θ read from the dedicated area of the disc 100. As a result, when the two relative angles Θ coincide with each other, the authenticity determination / output control unit 15 can output the content data reproduced from the disc 100 in the subsequent normal reproduction mode from the output circuit 12, and the two relative angles Θ are equal. If not, the output circuit 12 is controlled so that the reproduced content data cannot be output from the output circuit 12. If the relative angles Θ do not match, the reproduction of the content data by the optical pickup 3 itself may be stopped.

  According to the present embodiment, two points at specific positions of the first layer and the second layer of the disc 100, in this example, the head portions of chapters A and B are read with the disc 100 rotating at a constant rate. Since the relative angle of the first layer and the second layer of the disc 100 is detected based on the read time difference, the relative angle can be detected with high accuracy. Moreover, in detecting the relative angles of the first layer and the second layer of the disc 100, no expensive parts are added or parts are added, and the software supports the conventional reproduction. By using the configuration of the apparatus as it is, the relative angles of the first layer and the second layer of the disk 100 can be detected with high accuracy at low cost. Accordingly, it is possible to easily and inexpensively realize the reproduction prevention of the pirated edition by the authenticity determination of the disc 100 using the fact that the relative angles of the first layer and the second layer of the disc 100 are different for each disc.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary, it can implement also with another various form in a concrete structure, a function, an effect | action, and an effect. In the above embodiment, the specific data A and B are read out by CAV (Constant Angular Velocity) only when the relative angle between the layers of the disk 100 is usually obtained by a device that reads out data from the disk 100 by CLV. In the drive to be used, information recorded in CLV using a large memory space is read at high speed with CAV, and CAV reading is performed so that the information once written in the memory is read appropriately. In this case, the same relative angle calculation can be realized by repeatedly reading the signal at point A and the signal at point B by track jump (at least twice).

Further, in M-CLV (Modified CLV), the point A and the point B can be selected and calculated in the same rotation speed zone. Further, even when CLV reading is performed, if the change in the rotation speed from the point A to the point B can be ignored or the speed change curve can be calculated, the rotation may not be constant. That is, the calculation of the relative angle between the disk layers for preventing piracy is a necessary condition that the eigenvalue for each disk can be obtained with good reproducibility. If the rotation is not constant, it is difficult to generate an error if the information on the same position is used for the radius of the points A and B.

  Furthermore, since the present invention calculates the relative angle of the two signals on the disc only by means of signal readout, the present invention can be similarly applied to a multilayer disc, and can detect the interlayer angle between any two layers with high accuracy. The authenticity of the multilayer disc can be determined in the same way.

1 is a block diagram showing a configuration of a disc playback apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing an angle calculation process between two layers of a disk by the apparatus shown in FIG. 1. It is a figure explaining the detail of the calculation process of the relative angle between two layers of the disk shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Spindle motor, 2 ... Spindle motor control part, 3 ... Optical pick-up (OP), 4 ... Optical pick-up control part, 5 ... Thread motor, 6 ... Thread motor control part, 7 ... Read processor , 8... Decoding unit, 9... ECC processing circuit, 10... Buffer memory, 11... Compression / decompression unit, 12. ...... Authentication judgment / output control unit, 16 ... System control unit, 100 ... Disk.

Claims (8)

And rotating the disk recording medium at a constant speed,
Detecting a first time of reading A data recorded on the A layer of the disk recording medium;
A second time for reading the B data recorded on the B layer of the disk recording medium is detected at a position on the same circumference or in the vicinity of the same circumference from the rotation center of the A data and the disk recording medium. Steps,
Calculating an interlayer relative angle between the A layer and the B layer of the disk recording medium from the difference between the first time and the second time;
Reading interlayer relative angle information indicating an interlayer relative angle between the A layer and the B layer from the disk recording medium;
Comparing the calculated interlayer relative angle with the read interlayer relative angle information;
A disc playback control method comprising : The rotation period of the disk recording medium is t, the reading time of the A data is Ta, the reading time of the B data is Tb, the time difference between the time Ta and the time Tb is D, and D is obtained by dividing by t. 2. The disk reproduction control method according to claim 1, wherein when the remainder is p, the relative angle between the A layer and the B layer is obtained by calculation of 360 (degrees) / t * p. 2. The disk playback control method according to claim 1, wherein the disk recording medium is a two-layer optical disk . A disk reproducing apparatus for reading out the data by accessing an optical pickup at a recording location of data recorded in an arbitrary layer of a disk recording medium having a plurality of recording layers,
Rotating means for rotating the disk recording medium at a constant speed;
Access the optical pickup to read the A data of the A layer of the disk recording medium, and access the optical pickup to the same circumference from the rotation center of the A data and the disk recording medium or the vicinity on the same circumference Reading means for reading out B data recorded on the B layer of the disk recording medium at the position of
Timing means for timing a time for reading A data and b time for reading B data with the optical pickup;
Interlayer angle detection means for calculating an interlayer relative angle between the A layer and the B layer of the disk recording medium based on the time difference between the time a and the time b,
Interlayer relative angle information indicating an interlayer relative angle between the A layer and the B layer of the disk recording medium recorded in advance on the disk recording medium is read, and the calculated interlayer relative angle and the read interlayer relative angle information are read. A comparison means for comparing
Lud be equipped with a disk reproducing apparatus. 5. The disc reproducing apparatus according to claim 4, further comprising a control unit that performs reproduction control based on the comparison result.   6. The disc reproducing apparatus according to claim 5, wherein the control means controls whether or not content data reproduced from the disc is output.   The rotating means temporarily rotates the disk recording medium at a constant speed, and then rotates the disk recording medium so that data can be read from the disk recording medium by a constant linear velocity method. Item 5. A disk reproducing device according to item 4.   5. The disk reproducing apparatus according to claim 4, wherein the disk recording medium is an optical disk having two layers.

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