JPH08147856A - Optical disk, magneto-optical disk reproducing apparatus and reproducing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize an optical disc reproducing apparatus and its method that prohibit the unlimited use of video signals, audio signals, or other digital data, and effectively act to protect copyrights. [Structure] Copy protection information, information that limits the number of playbacks,
Alternatively, when information similar to that is received, the management information is recorded in the management data area 102 of the optical disc 101. When the data in the user data area 103 is reproduced, the optical pickup 104 is controlled via the reproduction laser power controller 108 according to the management information, and a laser power larger than the normal reproduction laser power is emitted. In this case, the recorded data deteriorates every time the data on the optical disc 101 is reproduced. Therefore, unlimited use of data can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to limiting unlimited reproduction of recorded information, and more particularly to a rewritable optical disk and magneto-optical disk reproducing apparatus and a reproducing method thereof.

[0002]

2. Description of the Related Art Conventionally, magnetic tapes, magnetic disks, magneto-optical disks, optical disks, etc. have been known as storage media capable of recording and reproducing information (data), and video signals, audio signals, digital signals for computers, etc. Record on a storage medium. However, if all the data can be recorded or reproduced on these storage media many times, the copyright of the recorded data may not be protected. It also allows a third party to copy data indefinitely. Therefore, there is one that manages video signals, audio signals, or other digital signals by prohibiting copying or providing guard information that limits the number of times of use.

Among them, as a copy protection method of a video signal which is currently used, there is "copy protection method and apparatus for video program" in Japanese Patent Laid-Open No. 63-107281. In this example, a predetermined waveform indicating that the video signal is prohibited from being copied is applied within the blanking period of the video signal. When the video signal is received by the recording device, a signal having a predetermined waveform is detected, and recording of the video signal is automatically prohibited.

[0004]

However, since a device which decodes such a copy guard signal to enable copying is already devised, the copyright can be protected to some extent, but it is very effective. It cannot be a method. Therefore, there is a problem that it is necessary to establish a method capable of effectively protecting copyright by preventing unlimited copying of data and limiting the number of times the copied data is used.

When data such as a video signal and an audio signal is used using a network such as CATV, the data is transferred at a speed different from the speed of the actually used data (during reproduction or recording). Therefore, the user side needs a data storage device in order to convert to the speed at the time of use. Rewritable optical disc, digital V for storage device
There are TRs, semiconductor memories, and the like. On the other hand, the use of the stored data must be restricted in some way in order to protect the copyright, but the conventional storage device described above does not have an effective means.

The present invention has been made in view of the above conventional problems, and it is possible to record the obtained data on an optical disk, but the reproduction of an optical disk or a magneto-optical disk which limits the number of times of reproduction and use thereof. An object of the present invention is to realize an apparatus and a reproducing method thereof.

[0007]

The invention according to claim 1 of the present application is an optical disk reproducing apparatus for reproducing information of an optical disk having a user data area and a management data area for managing user data, wherein a laser beam is applied to the optical disk. And reproducing the information in the management data area and the user data area, a data separating means for separating the user data and the management data obtained from the reproducing means, and a reproduction means for reproducing the management data according to the content of the management data. And a reproduction laser power control means for controlling the laser power.

In the invention of claim 2 of the present application, the reproduction laser power control means controls the management data area of the optical disk with the reproduction laser power equivalent to that at the time of normal reproduction, and only the user data area is set to a power equal to or higher than the reproduction laser power. It is characterized by controlling.

In the invention of claim 3 of the present application, the reproduction laser power control means controls the management data area of the optical disk with the reproduction laser power equivalent to that in the normal reproduction, and only the user data area is equal to or higher than the reproduction laser power. It is characterized in that it is controlled at a value equal to or lower than the recording laser power.

In the invention of claim 4 of the present application, the reproduction laser power control means controls the management data area of the optical disk with the reproduction laser power equivalent to that during normal reproduction, and only the user data area is equal to or higher than the reproduction laser power. It is characterized in that the erasing laser power is controlled at a value less than that.

The invention of claim 5 of the present application is an optical disk reproducing method for reproducing information of an optical disk having a user data area and a management data area for managing user data, wherein the management data recorded in the management data area is It is characterized in that when the user data in the user data area is read by performing reproduction with a specified reproduction laser power, the reproduction laser power is controlled according to the content of the corresponding management data for reproduction.

According to a sixth aspect of the present invention, there is provided a magneto-optical disk reproducing apparatus for reproducing information of a magneto-optical disk having a user data area and a management data area for managing user data, the laser light being applied to the magneto-optical disk. And reproducing the information in the management data area and the user data area, a data separating means for separating the user data and the management data obtained from the reproducing means, and a magneto-optical disk during reproduction depending on the content of the management data. It is characterized by comprising magnetic field generation means for applying an external magnetic field to the disk and magnetic field control means for controlling the magnetic field strength of the magnetic field generated by the magnetic field generation means.

According to a seventh aspect of the present invention, there is provided a magneto-optical disk reproducing apparatus for reproducing information from a magneto-optical disk having a user data area and a management data area for managing user data, wherein the magneto-optical disk has a laser. A reproducing means for irradiating light to reproduce information in the management data area and the user data area, a data separating means for separating user data and management data obtained from the reproducing means, and an optical signal for reproducing according to the contents of the management data. Magnetic field generation means for applying an external magnetic field to the magnetic disk, magnetic field control means for controlling the magnetic field strength of the magnetic field generated by the magnetic field generation means, and reproduction laser power control means for controlling the reproduction laser power according to the contents of the management data,
It is characterized by including.

In the invention of claim 8 of the present application, the magnetic field control means controls the external magnetic field only for the user data area when reproducing the magneto-optical disk.

In the invention of claim 9 of the present application, the magnetic field control means controls the strength of the magnetic field applied during reproduction of the magneto-optical disk,
The feature is that the magnitude of the applied magnetic field during recording is controlled.

According to a tenth aspect of the present invention, the magnetic field control means controls the strength of the magnetic field applied during reproduction of the magneto-optical disk to the magnitude of the applied magnetic field during erasure.

In the eleventh aspect of the present invention, the magnetic field control means controls the external magnetic field only for the user data area when reproducing the magneto-optical disk, and the reproduction laser power control means comprises the magneto-optical disk. The control data area is controlled with a reproduction laser power equivalent to that during normal reproduction, and only the user data area is controlled to have a power higher than the reproduction laser power.

A twelfth aspect of the present invention is a magneto-optical disk reproducing method for reproducing information on a magneto-optical disk having a user data area and a management data area for managing user data, which is recorded in the management data area. When the user data in the user data area is read by reproducing the specified management data with a specified reproduction laser power, the reproduction is performed while applying an external magnetic field to the magneto-optical disk according to the content of the corresponding management data. It is a thing.

A thirteenth aspect of the present invention is a magneto-optical disk reproducing method for reproducing information of a magneto-optical disk having a user data area and a management data area for managing user data, which is recorded in the management data area. When the user data in the user data area is read by reproducing the specified management data with the specified reproduction laser power, an external magnetic field is applied to the magneto-optical disk according to the content of the corresponding management data, and the reproduction laser power is changed. It is characterized by controlling and reproducing.

[0020]

According to the inventions of claims 1 to 6 having the above characteristics, the copy protection information, the information for limiting the number of times of reproduction, or similar information is recorded in advance on the optical disc as the management data together with the user data. There is. When the information on the optical disk is reproduced, the data in the management data area is referred to, and in the case of copy prevention or restriction, a signal having a power larger than the laser power used for normal reproduction is irradiated to read the signal. By doing so, the recorded data is deteriorated little by little every time the information is reproduced, and the reliability of the read data after the first time is deteriorated. This makes it difficult to use the data indefinitely.

According to the invention of claims 7 to 13, the copy protection information, the information for limiting the number of times of reproduction, or similar information is recorded in advance on the magneto-optical disk as the management data together with the user data. When reproducing the information on the magneto-optical disk, refer to the data in the management data area to irradiate a power larger than the laser power used for normal reproduction or to apply an external magnetic field to the magneto-optical disk when copying is to be prevented or restricted. To do. In this case,
Each time the information is reproduced, the recorded data deteriorates little by little, and the reliability of the user data read after the first time deteriorates. Therefore, it becomes difficult to use the data indefinitely. Therefore, the copyright can be protected for specific information.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disk reproducing apparatus according to a first embodiment of the present invention will be described with reference to FIG. Figure 1 shows the first
It is a block diagram which shows the schematic structure of the optical disc reproducing apparatus of an Example. As shown in the figure, the information storage medium used in this embodiment is an optical disc 101 capable of recording and reproducing data, and is, for example, a phase change type optical disc. The management data area 10 is provided on the recording / reproducing surface of the optical disc 101.
2 and a user data area 103 are provided. When reproducing the information of the optical disc 101 divided into the two areas as described above, first, the management data in the management data area 102 is reproduced.

The laser power output from the optical pickup 104 in this case is a normally determined value, and as long as the laser power is reproduced with this power, the recorded data is hardly deteriorated no matter how many times the optical disc 101 is reproduced. . The reproduced signal is amplified by the reproduced signal processor 105,
Processing such as binarization, synchronization, demodulation and error correction is performed.

The signal processed by the reproduction signal processor 105 is input to the data separator 106 and separated into management data and user data. This management data is stored in the memory 107. The reproduction laser power controller 108 is the memory 1
The reproduction laser power is controlled by referring to part of the management data accumulated in 07. For example, when the management data includes information that limits the number of times of use, when reproducing the corresponding user data, the reproduction laser power controller 108 has a power larger than the normal reproduction laser power and less than or equal to the recording laser power. Alternatively, laser light having an erase laser power or less is applied to the optical pickup 104.

As a result, in the user data reproduced from the user data area 103 of the optical disc 101, since the laser power output from the optical pickup 104 is larger than the normal reproduction power, the recorded data immediately after being read is deteriorated. . However, only in the first reproduction, since the data is not deteriorated, a signal equivalent to that in the case of reproduction with normal reproduction power can be obtained. Therefore, the first read data is processed by the reproduction signal processor 105, and then passes through the data separator 106 to be processed by the video / audio signal processor 10.
9 is input. The video / audio processor 109 performs processing such as video signal / audio separation and decoding, and D / A conversion processing. Then, the video signal and the audio signal are output to the outside, respectively. Here, the optical pickup 104 and the reproduction signal processor 105 constitute a reproduction means for the optical disc 101.

FIG. 2 is a block diagram showing the schematic arrangement of the magneto-optical disk reproducing apparatus of the second embodiment. The information storage medium used in this embodiment is a magneto-optical disk 201 capable of recording and reproducing data. Signal recording is performed by irradiation with laser light and an external magnetic field. The reproduction of the signal is performed by irradiating the laser light and detecting the rotation of the plane of polarization of the light. Further, the signal is erased by applying an external magnetic field in the opposite direction to that at the time of recording.

Similar to the optical disc 101 of FIG. 1, a management data area 202 and a user data area 203 are provided on the recording / reproducing surface of the magneto-optical disc 201 of this embodiment. In order to reproduce the information on the magneto-optical disk 201, the management data in the management data area 202 is first reproduced. The laser power output from the optical pickup 204 in this case is a normally determined value, and as long as the laser power is reproduced with this power, the recorded data is not deteriorated no matter how many times it is reproduced. Further, no magnetic field is generated from the magnetic field generator 209 when the signal is reproduced.

The signal reproduced by the optical pickup 204 is input to the reproduction signal processor 205, where the reproduction signal is amplified, binarized, synchronized, demodulated and error-corrected. The signal processed by the reproduction signal processor 205 is input to the data separator 206 and separated into management data and user data. The management data is stored in the memory 207.
The reproduction laser power controller 210 controls the reproduction laser power with reference to part of the management data stored in the memory 207.

For example, when there is a copy prohibition signal in the management data, when reproducing the corresponding user data, the magnetic field controller 208 gives a control signal to the magnetic field generator 209 to generate an external magnetic field. The external magnetic field at this time is the magnetic field strength during recording or erasing. Alternatively, the reproduction laser power controller 210 gives a control signal to the optical pickup 204 so as to output a power larger than the normal reproduction laser power. Alternatively, the magnetic field controller 208 is controlled to generate a magnetic field from the magnetic field generator 209, and at the same time, the reproduction laser power controller 210 is controlled to output a power larger than the normal reproduction laser power.

If any of the above three methods is applied during reproduction, the user data reproduced from the user data area of the magneto-optical disk 201 will be deteriorated each time it is reproduced. However, since the data is read before the deterioration of the data occurs only in the first reproduction, the data can be reproduced with the same reliability as when the reproduction is performed with the normal reproduction power. Next, the first signal processed by the reproduction signal processor 205 passes through the data separator 206 and is input to the video / audio signal processor 211. The video / audio processor 211 performs predetermined processing such as video decoding, audio decoding, or D / A conversion processing, and outputs video signals and audio signals, respectively.

After the second time, it is difficult to obtain a normal video output or audio output because the data is deteriorated. In addition, if reproduction is performed by applying a magnetic field and a laser power of a level used during erasing, the user data is completely erased, and unlimited copying is impossible. In the above embodiments, the video signal or the audio signal is used as the user data, but it may be a character signal or computer data.

Next, the reproducing method of the optical disk or the magneto-optical disk in the first and second embodiments will be described with reference to the flowchart of FIG. In the following description, the optical disc 101 and the magneto-optical disc 201 are expressed as optical discs. First, in step S1, the management data of the optical disc is reproduced. The reproduction laser power at this time is a value defined in advance. After the reproduction of the management data is completed in step S2, the process proceeds to step S3 to refer to the contents of the management data. Here, for example, when the management data for limiting the number of reproduction times to one is recorded, the process proceeds to step S4, and the user data area is accessed.

After that, the process proceeds to step S5, and the reproduction laser power is switched to set it higher than the normal reproduction laser power. In this case, if the set value of the reproduction laser power is set to the laser power at the time of erasing, it is possible to surely erase the data while reproducing. Next, in step S6, the user data area of the optical disc is reproduced. When the reproduction is completed in the next step S7, the process proceeds to step S8, the original reproduction laser power is restored again, and the series of operations is completed.

If the allowable number of reproductions without deterioration is registered as n (n> 1) times in step S3, the reproduction laser power is not increased until (n-1) times in the process of step S5. . Further, the optical pickup 204 and the reproduction signal processor 205 constitute a reproducing means of the magneto-optical disk 201.

Further, in the case of a magneto-optical disk, instead of switching the reproducing laser power as in this flowchart, the intensity of the external magnetic field (including ON / OFF) is controlled, or the reproducing laser power is switched at the same time. Controls the strength of the external magnetic field (including ON / OFF).

[0036]

As described above, according to the present invention, data of a video signal, an audio signal, or other digital data recorded on a rewritable optical disk or magneto-optical disk can be deteriorated according to the number of times of reading. .
For this reason, it is possible to prohibit the reading or copying of specific information without limitation, which is effective for copyright protection. Further, with respect to information such as a video signal and an audio signal transmitted from a network such as CATV, as long as the information is temporarily stored in the optical disc or the magneto-optical disc as a buffer, the action of copyright protection works.
Further, even if the disc is reproduced more than the specified number of times, the quality of the information is somewhat lost, but the content can be grasped by the user. In particular, the major feature is that the quality of information deteriorates in proportion to the number of reproductions.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an optical disc reproducing apparatus in a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a magneto-optical disk reproducing apparatus according to a second embodiment of the present invention.

FIG. 3 is a flow chart showing a reproducing method of an optical disc or a magneto-optical disc in each embodiment of the present invention.

[Explanation of symbols]

 101 optical disk 102, 202 management data area 103, 203 user data area 104, 204 optical pickup 105, 205 reproduction signal processor 106, 206 data separator 107, 207 memory 108, 210 reproduction laser power controller 109, 211 video / audio Signal processor 201 Magneto-optical disk 208 Magnetic field controller 209 Magnetic field generator

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Claims (13)

[Claims] 1. An optical disk reproducing apparatus for reproducing information of an optical disk having a user data area and a management data area for managing user data, wherein the optical disk is irradiated with laser light to display information of the management data area and the user data area. Reproducing means for reproducing, data separating means for separating the user data and the management data obtained from the reproducing means, and reproducing laser power control for controlling the reproducing laser power of the reproducing means according to the content of the management data. An optical disk reproducing apparatus comprising: 2. The reproduction laser power control means controls the management data area of the optical disk with a reproduction laser power equivalent to that during normal reproduction, and controls only the user data area to a power equal to or higher than the reproduction laser power. The optical disk reproducing apparatus according to claim 1, wherein the optical disk reproducing apparatus is provided. 3. The reproduction laser power control means controls the management data area of the optical disk with a reproduction laser power equivalent to that during normal reproduction, and only the user data area is equal to or higher than the reproduction laser power and equal to or lower than the recording laser power. The optical disc reproducing apparatus according to claim 1, wherein the optical disc reproducing apparatus is controlled by the value of. 4. The reproduction laser power control means controls the management data area of the optical disc with a reproduction laser power equivalent to that during normal reproduction, and only the user data area is equal to or higher than the reproduction laser power and equal to or lower than the erase laser power. The optical disc reproducing apparatus according to claim 1, wherein the optical disc reproducing apparatus is controlled by the value of. 5. An optical disc reproducing method for reproducing information of an optical disc having a user data area and a management data area for managing user data, wherein the management data recorded in the management data area is reproduced with a prescribed reproduction laser power. When reproducing and reading the user data in the user data area,
An optical disk reproducing method characterized in that reproduction is performed by controlling a laser power for reproduction according to the content of corresponding management data. 6. A magneto-optical disk reproducing apparatus for reproducing information of a magneto-optical disk having a user data area and a management data area for managing user data, wherein the magneto-optical disk is irradiated with a laser beam and a management data area is formed. Playback means for playing back information in the user data area, data separation means for separating the user data and the management data obtained from the playback means, and external to the magneto-optical disk during playback according to the contents of the management data. A magneto-optical disk reproducing apparatus comprising: a magnetic field generating means for applying a magnetic field; and a magnetic field control means for controlling the magnetic field strength of the magnetic field generated by the magnetic field generating means. 7. A reproducing apparatus of a magneto-optical disk for reproducing information of a magneto-optical disk having a user data area and a management data area for managing user data, wherein the magneto-optical disk is irradiated with a laser beam to control data area. And reproducing means for reproducing information in the user data area, data separating means for separating the user data and the management data obtained from the reproducing means, and the magneto-optical disk during reproduction according to the contents of the management data. Magnetic field generation means for applying an external magnetic field, magnetic field control means for controlling the magnetic field strength of the magnetic field generated by the magnetic field generation means, and reproduction laser power control means for controlling reproduction laser power according to the contents of the management data. A magneto-optical disk reproducing apparatus comprising: 8. The magneto-optical disk reproducing apparatus according to claim 6, wherein the magnetic field control means controls an external magnetic field only for the user data area when reproducing the magneto-optical disk. . 9. The magnetic field control means controls the strength of a magnetic field applied when reproducing the magneto-optical disc,
7. A magneto-optical disk reproducing apparatus according to claim 6, wherein the magnitude of an applied magnetic field during recording is controlled. 10. The magnetic field control means controls the strength of a magnetic field applied during reproduction of the magneto-optical disc,
7. A magneto-optical disk reproducing apparatus according to claim 6, wherein the magnitude of an applied magnetic field at the time of erasing is controlled. 11. The magnetic field control means controls an external magnetic field only for the user data area when reproducing the magneto-optical disk, and the reproduction laser power control means manages the magneto-optical disk. 8. The magneto-optical disk reproducing apparatus according to claim 7, wherein the data area is controlled with a reproducing laser power equivalent to that in normal reproduction, and only the user data area is controlled to have a power equal to or higher than the reproducing laser power. . 12. A magneto-optical disk reproducing method for reproducing information of a magneto-optical disk having a user data area and a management data area for managing user data, wherein the management data recorded in the management data area is defined. When reproducing user data in the user data area by reproducing with reproduction laser power,
A magneto-optical disk reproducing method characterized in that reproduction is performed while applying an external magnetic field to the magneto-optical disk according to the content of corresponding management data. 13. A magneto-optical disk reproducing method for reproducing information of a magneto-optical disk having a user data area and a management data area for managing user data, wherein the management data recorded in the management data area is defined. When reproducing user data in the user data area by reproducing with reproduction laser power,
A magneto-optical disk reproducing method characterized in that an external magnetic field is applied to the magneto-optical disk according to the content of corresponding management data, and the reproducing laser power is controlled to reproduce.