JP3197742B2 - Optical disk and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk having a duplication preventing function and a reproducing apparatus.

[0002]

2. Description of the Related Art Although a copy prohibition bit is defined in a conventional optical disc such as a compact disc, a reproduction apparatus for the optical disc does not have a copy protection function.
This is an optical disk that can be written only once and can be played back by a normal playback device. However, it is more expensive than purchasing an optical disk officially, and a device for writing to an optical disk is expensive and not widely used. For that reason, there was almost no need to take countermeasures against illegal duplication. However, as games and the like are recorded on optical discs, the price of optical discs rises along with the rise in software prices, and on the other hand, the price of optical discs that can be written only once and can be played back by ordinary playback devices has fallen. By doing so, it becomes cheaper to copy illegally, so a duplication prevention function has been demanded.

An optical disk is generally manufactured by producing a master, a mother, and a stamper from an original master and copying them in large quantities by injection molding. Alternatively, a stamper may be directly manufactured from the master. An optical disc master is generally coated with a photoresist on a glass substrate whose surface has been polished, exposed to light using a laser beam whose intensity is modulated by an information signal to be recorded, developed, and developed into an uneven signal corresponding to the sensitivity. Is formed. Hereinafter, this uneven signal is referred to as a pit row. FIG. 6 is an explanatory view showing the configuration of a conventional recording apparatus for a master optical disc. Further, the description of the laser optical system for focus control and the beam expander of the recording laser optical system is omitted.

In FIG. 6, reference numeral 1 denotes a signal source for voice and data to be recorded, 2 denotes a recording equalizer, 3 denotes a beam modulator for modulating the intensity of a laser beam, 4 denotes a recording laser light source, 5 denotes a mirror, and 6 denotes a mirror. Reference numeral 7 denotes a lens actuator for controlling the focus of the lens, reference numeral 7 denotes an optical disk master made of a glass plate coated with photoresist, and reference numeral 8 denotes a spindle motor for driving the optical disk master 7 to rotate.

The signal generated by the signal source 1 is changed in pulse width by a recording equalizer 2 and is input to a beam modulator 3 to modulate the intensity of a laser beam emitted from a recording laser light source 4. The intensity-modulated laser beam is deflected by a mirror 5, narrowed down to an optical disk master 7 through a lens whose focus is controlled by a lens actuator 6, and exposes a photoresist on the optical disk master 7. While rotating the optical disk master 7 coated with the photoresist with the spindle motor 8, the point where the laser beam is narrowed down is moved uniaxially, thereby recording the pit array in a spiral shape.

[0006]

However, in recent years,
Software such as games is recorded on the optical disc, and the price of the optical disc is also increasing due to the rise in the price of the software. On the other hand, along with the drop in the price of optical discs that can be written only once and reproduced by ordinary playback devices,
Since it is cheaper to copy illegally, a duplication prevention function has been desired.

[0007] An object of the present invention is to provide an optical disk and a reproducing apparatus having a duplication preventing function.

[0008]

In order to achieve this object, an optical disk according to the present invention is an optical disk having a pit array arranged on a spiral recording track, wherein a plurality of signal pit arrays are provided between the recording tracks. provided, and before Symbol signal pit row
Positions on both sides smell of the inner periphery of the adjacent recording tracks
Te, the recording tracks provided a portion not disposed pin Tsu preparative column, and on both sides the position of the inner and outer circumferences of the front <br/> type recording tracks adjacent to the signal pit string is not provided portions of said recording track characterized in that a pit string.

In addition, the length of the portion of the innermost recording track where the pit row is not arranged is longer than the length of the signal pit row between the recording tracks to be reproduced last, so that the signal Immediately after the end of the pit train, there is no pit train on the inner recording track.

In addition, the beginning of the first reproduced signal pit sequence and the beginning of the last reproduced signal pit sequence in an area in which a plurality of signal pit sequences are provided between recording tracks form one round of the recording track. Not to exceed.

[0011] The present invention is characterized in that a signal of a fixed pattern is recorded on recording tracks immediately before the start and immediately after the end of the area provided with the plurality of signal pit strings.

[0012] An optical disk arranged row of pits in the spiral recording track, wherein the provided plurality of signal pit strings on the recording tracks, pits in the recording track on both sides the inner periphery of the front SL signal pit string A portion where no row is arranged is provided, and a portion adjacent to the signal pit row provided between the recording tracks is provided.
At both sides of the inner and outer circumferences of the recording tracks in contact with each other,
Providing a portion where no pit row is arranged on the recording track,
And a portion adjacent to a portion where the signal pit row is not provided.
An optical disc reproducing apparatus in which pit rows of the recording tracks are arranged at both sides of the inner and outer peripheries of the recording tracks , wherein an area in which a plurality of signal pit rows are provided between the recording tracks is reproduced a plurality of times. A storage unit for storing a reproduction signal and a control unit for stopping subsequent reproduction when the reproduction signal is the same each time are provided.

[0013]

According to the optical disk, in the area where a plurality of signal pit strings are provided between the recording tracks, the recording tracks to be reproduced following the signal pit strings have a half probability that the signal pits between the recording tracks will not be reproduced. This is the recording track on the inner or outer circumference side of the row.

Further, a portion of the recording track on the inner peripheral side of the signal pit row where the pit row is not arranged is made longer than an end portion of the signal pit row reproduced last, and the signal pits reproduced first and last. By making the start end of the row not exceed one round of the recording track, the area provided with a plurality of signal pit rows can be reproduced once and escaped.

Further, an area having a plurality of signal pit strings can be repeatedly reproduced by signals recorded on recording tracks immediately before and after the start of an area having a plurality of signal pit strings.

According to the reproducing apparatus, the storage section and the control section reproduce a plurality of signal pit arrays between recording tracks of the optical disk a plurality of times and store the reproduced signals so that the reproduced signals are always the same. When there is, the subsequent reproduction can be stopped.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory view of an embodiment of an optical disk according to the present invention, wherein 9 is an optical disk, 10 is a pit array of recording tracks on which a signal sequence such as data is recorded, and 11 is provided between recording tracks. This is a signal pit row.

On the optical disk 9, a signal pit row 11 between recording tracks and a portion where the pit row 10 of the recording track is not arranged on the recording tracks on both sides of the inner and outer circumferences of the signal pit row 11 are arranged.
(Hereinafter referred to as pit-free trains) and signal pit trains
11 is provided in plurality.

The optical disk 9 generally records signals spirally from the innermost circumference to the outer circumference. In a compact disk or the like, a lead-in area is provided at the innermost periphery, and index information of the optical disk 9 and the like are recorded. Also in the optical disc 9 of the present embodiment, if an area where a plurality of signal pit rows 11 and non-pit rows on both sides of the inner and outer circumferences of the signal pit row 11 are provided on the recording track is provided in the innermost peripheral portion corresponding to the lead-in area,
It is desirable to be able to determine whether the optical disk 9 has been illegally copied at the start of reproduction.

Signal pit row 11 provided between recording tracks
When reproducing an area provided with a plurality of non-pit rows on both sides of the inner and outer peripheries of the signal pit row 11 (hereinafter referred to as a duplication prevention area), the pit row 10 of the recording track to be reproduced following the signal pit row 11 Becomes the pit row 10 of the recording track on the inner or outer circumference side of the signal pit row 11 with a half probability.

This is because when the reproduction beam passes through the end of the signal pit train 11, the pit train 10 of the inner recording track is recorded.
And the magnitude of the tracking signal by the pit row 10 of the recording track on the outer peripheral side becomes equal,
Depending on the state of the tracking control at the time when the reproduction beam passes through the end of the signal pit row 11, it shifts toward the inner side or the outer side,
This is because it is drawn into the pit row 10 of the recording track closer by tracking control.

In addition, both when the inner recording track is being reproduced and when the outer recording track is being reproduced,
When entering the non-pit row of the recording track, there is no pit row 10 of the recording track other than the signal pit row 11 to be reproduced next, and the pit row 10 of the adjacent recording track is the signal pit row.
Since it is twice as far as 11, the signal pit train 11 is reproduced.

FIG. 2 is an enlarged view of the vicinity of the end of the signal pit string 11 between the recording tracks to be reproduced last, and 10a is a non-pit row on the inner peripheral side of the signal pit row 11 to be reproduced last. . As shown in FIG. 2, if the inner pit-free row 10a is made longer than the end of the signal pit row 11, the pits on the outer recording track always follow the last reproduced signal pit row 11. Play column 10.

When the reproduction beam passes through the end of the signal pit row 11, there is no pit row 10 of the recording track near the inner circumference side, and there is a pit row 10 of the recording track near the outer circumference side. That is, the tracking control is performed to the pit row 10 of the recording track on the outer peripheral side. Thereby, the duplication prevention area can be reproduced once and escaped.

FIG. 3 shows that the beginning of the first reproduced signal pit string 11 and the beginning of the last reproduced signal pit string 11 in the duplication prevention area extend over one round of the recording track, and the signal pit string 11 is extended. It is an enlarged view of the part which has. When the start end of the signal pit string 11 reproduced first and the start end of the signal pit string 11 reproduced last in the duplication prevention area exceed one round of the recording track, the signal pit is reproduced first as shown in FIG. The signal pit row 11 to be reproduced last is provided adjacent to the outer peripheral side of the signal pit row 11. In this case, there is a possibility that the inside of the duplication prevention area is reproduced many times and it is impossible to escape from this area.

As described above, the inner non-pit row 10a is made longer than the end of the signal pit row 11 reproduced last at the end of the copy protection area, and the signal pit row reproduced first at the end of the copy protection area. By preventing the start end of 11 and the start end of the last reproduced signal pit string 11 from going over one round of the recording track, the signal pit string 11 reproduced last at the end of the duplication prevention area, Pit row 10 of the outer recording track
Is reproduced, and this area can be reproduced once and escaped.

Also, a signal of a fixed pattern is recorded on recording tracks immediately before the start and immediately after the end of the copy protection area,
When the duplication prevention area is reproduced a plurality of times and the reproduction signals are compared, the reproduction prevention area is used to store the reproduction signal or to move the reproduction signal to a reproduction position for reproducing again.

Next, a reference example of the recording apparatus according to the present invention will be described with reference to FIG. The same reference numerals are given to those having the same functions and effects as those of FIG. 6 described in the conventional example, and the detailed description thereof will be omitted. FIG. 4 is an explanatory view showing the configuration of a recording apparatus for an optical disk master. Reference numeral 12 denotes a beam deflector for deflecting a laser beam, and reference numeral 13 denotes a control unit for controlling the beam deflector 12. Here, as in the conventional example, the description of the laser optical system for focus control and the beam expander of the laser optical system for recording is omitted.

While the optical disk master 7 is driven to rotate by the spindle motor 8, the point where the laser beam is narrowed down is moved uniaxially, and the pit array 10 of the recording track is spirally recorded. At this time, the direction of the laser beam is changed by using the beam deflector 12, and the signal pit train 11 is inserted between the recording tracks.
Record The control unit 13 sends a signal to the beam deflector 12 to change the direction of the laser beam.

When the pit train 10 of the recording track is recorded spirally, no signal is sent to the beam deflector 12, but only when the signal pit train 11 between the recording tracks is recorded, a signal is sent to the beam deflector 12. Change the direction of the laser beam. When the laser beam whose direction has been changed is incident on the lens actuator 6, the position narrowed down in the lateral direction by a distance determined by the product of the incident angle and the focal length of the lens changes.

For example, if the focal length of the lens is to be shifted by 0.8 microns, if the focal length of the lens is 2 mm, it is necessary to change the angle of 0.4 micro radians to enter the lens. Also beam deflector
Numeral 12 is an element for changing the direction of a laser beam according to a control signal, and is an AO (Acousto-Optic) using an acousto-optic effect.
EO deflector using modulator and electro-optic effect
(Electro-Optic Deflector) (for example, models 310A and 311A manufactured by Conoptics) are commercially available.

From the above, the signal pit train 11 between the recording tracks may be recorded by shifting the laser beam to the outer periphery when recording the inner recording track, or by recording the outer recording track. When recording, the laser beam may be shifted to the inner peripheral side for recording.

Next, an embodiment of the reproducing apparatus of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram showing the configuration of an optical disk reproducing apparatus, wherein 9 is an optical disk, 14 is a spindle motor, and 15 is a pit array 10 and a signal pit array 11 of the recording tracks shown in FIG. Optical pickup, 16 is RF from optical pickup 15
An analog waveform shaping unit for shaping a signal, 17 a digital demodulation unit, 18 a digital signal processing unit, 19 a control unit, 20 a storage unit which is a storage device having a capacity capable of storing a signal in the copy protection area a plurality of times, 21 Is a focus servo unit that drives and controls the optical pickup 15 so that the signal surface of the optical disk 9 is always in focus, 22 is a tracking servo unit that drives and controls the semiconductor laser of the optical pickup 15 so that the focus of the semiconductor laser follows the recording track, and 23 Reference numeral denotes a rotation servo unit for controlling the drive such as the steady rotation of the spindle motor 14.

The optical disk 9 is driven to rotate by a spindle motor 14. The semiconductor laser is focused on the signal surface of the optical disk 9 by the optical pickup 15, and the intensity of the light reflected from the signal surface is converted into an electric signal by a photodiode or the like to obtain an RF signal. The RF signal is subjected to waveform shaping by the analog waveform shaping unit 16, then demodulated into a digital signal by the digital demodulation unit 17, digital signal processing is performed by the digital signal processing unit 18, and the original signal is reproduced.

When the control unit 19 detects a signal of a fixed pattern immediately before the start of the duplication prevention area (hereinafter, referred to as a start signal), the control unit 19 stores the reproduced signal in the storage unit 20. A fixed pattern signal immediately after the end of the duplication prevention area (hereinafter, referred to as an end signal)
Is detected, the storage in the storage unit 20 is terminated, and the tracking servo unit 22 is instructed to move the optical pickup 15 to a portion where the start signal is recorded. The reproduced signal from the start signal to the end signal is stored in the storage unit 20 again, compared with the previously stored reproduced signal, and if they are the same, the subsequent reproduction is stopped.

The reproducing apparatus reproduces a plurality of portions in which a plurality of non-pit rows are provided on both sides of the signal pit row 11 and the inner and outer peripheries of the signal pit row 11 between tracks. A function to stop subsequent reproduction is added. Here, an example in which the reproduction from the start signal to the end signal is performed twice has been described. However, the reproduction may be performed three or more times and the reproduction thereafter may not be continued unless all the reproduction signals are different.

When reproducing the duplication prevention area, the pit row 10 of the recording track to be reproduced following the signal pit row 11
Becomes the pit row 10 of the recording track on the inner or outer circumference side of the signal pit row 11 with a half probability. Further, when the duplication prevention area is reproduced a plurality of times, the probability that the same signal is reproduced becomes a probability of 1 / power, and approaches zero when the number of signal pit strings 11 is increased. For this reason, in the regular optical disk 9, when the copy protection area is reproduced a plurality of times, the reproduced signal is different each time.

When the data of the optical disk 9 is copied to a disk medium which can be written once and reproduced by an ordinary reproducing apparatus, the regular optical disk 9 is reproduced by the reproducing apparatus,
A write beam is modulated based on a signal demodulated into a digital signal to be written. A device for writing data on the duplicate optical disk 9 includes a signal pit train 11 between recording tracks.
Cannot be written, a signal is recorded on the recording track also in the portion of the copy protection area.

When the reproducing apparatus reproduces the duplicated optical disk 9, the same signal is reproduced every time even if a part which is originally a copy protection area is reproduced a plurality of times. If the reproduction signal is the same every time, the function of stopping the subsequent reproduction is added to the reproduction apparatus, and the reproduction is stopped.

The optical disk 9 shown in FIG. 1 can be manufactured in a large amount at low cost because the optical disk 9 can be manufactured in exactly the same steps as the conventional optical disk 9 except for recording the signal pit rows 11 between the recording tracks of the master optical disk 7. Further, the optical disk 9 and the reproducing apparatus for the optical disk 9 can prevent reproduction of the optical disk 9 that has been illegally copied, and can prevent illegal duplication of the optical disk 9.

[0042]

According to the optical disk of the first, second, third, and fourth aspects, the recording tracks to be reproduced following the signal pit train in the duplication prevention area have a half probability of the signal pits between the recording tracks. This is the recording track on the inner or outer circumference side of the row. In addition, the length of the non-pit row on the inner circumference side should be longer than the end of the signal pit row reproduced last, and the start end of the signal pit row reproduced first and last should not exceed one round of the recording track. Thus, the area provided with a plurality of signal pit strings can be reproduced once and escaped, and can be reproduced a plurality of times by the start signal and the end signal before and after the copy protection area. When a region having a plurality of signal pit trains is reproduced a plurality of times, the probability of reproducing the same signal is a probability of a power of 2, and if the number of signal pit trains between recording tracks is increased, it becomes zero. When the duplication prevention area is reproduced a plurality of times, the reproduction signal is different each time, so that a legitimate optical disc can be determined.

According to the reproducing apparatus of the fifth aspect,
If the control unit reproduces the duplication prevention area a plurality of times, and the storage unit that stores the reproduced signal and the reproduced signal are the same as a result of comparing the stored reproduced signal, the subsequent reproduction is stopped. The illegally duplicated optical disk cannot be reproduced, and the illegal duplication of the optical disk can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an optical disc according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing the vicinity of the end of a signal pit string between recording tracks to be reproduced last in an embodiment of the optical disc of the present invention.

FIG. 3 shows an embodiment of the optical disk according to the present invention, in which the beginning of the first reproduced signal pit sequence and the beginning of the last reproduced signal pit sequence in the duplication preventing area exceed one round of the recording track; It is an enlarged view which shows the part which has a row.

FIG. 4 is an explanatory diagram showing a configuration of a recording device for a master optical disc which is a reference example of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of an optical disk reproducing apparatus according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing the configuration of a conventional recording apparatus for a master optical disc.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Signal source, 2 ... Recording equalizer, 3 ... Beam modulator, 4 ... Recording laser light source, 5 ... Mirror, 6 ...
Lens actuator, 7 ... master optical disc,
8,14 ... spindle motor, 9 ... optical disk, 10 ...
Pit row of recording track, 10a: no pit row on inner side, 11: signal pit row, 12: beam deflector, 13,
19: control unit, 15: optical pickup, 16: analog waveform shaping unit, 17: digital demodulation unit, 18: digital signal processing unit, 20: storage unit, 21: focus servo unit,
22: Tracking servo section, 23: Rotating servo section.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B ^7/ 12-7/24

Claims (5)

(57) [Claims] 1. A disc arranged row of pits in the spiral recording track, wherein said providing a plurality of signal pit strings between recording tracks, adjacent to the previous SL signal pit string
On both sides the position of the inner periphery of the recording track, provided the portion not arranged row of pits on the recording track, and the signal
The recording track and the adjacent No. pit column provided no part
An optical disc, wherein pit rows of the recording tracks are arranged at both sides of the inner and outer peripheries. 2. The length of a portion of a signal pit row where no pit row is arranged in a recording track on the inner peripheral side is longer than the length of a signal pit row between recording tracks to be reproduced last, and a signal between recording tracks is recorded. 2. The optical disk according to claim 1, wherein immediately after the end of the pit row, there is no pit row in the inner recording track. 3. The beginning of the first reproduced signal pit sequence and the beginning of the last reproduced signal pit sequence in an area provided with a plurality of signal pit sequences between recording tracks form one round of the recording track. 3. The optical disk according to claim 1, wherein the value does not exceed the value. 4. The optical disc according to claim 1, wherein a signal of a fixed pattern is recorded on recording tracks immediately before and immediately after the start of the area provided with the plurality of signal pit strings. 5. A disc arranged row of pits in the spiral recording track, wherein said providing a plurality of signal pit strings between recording tracks, adjacent to the previous SL signal pit string
On both sides the position of the inner periphery of the recording track, provided the portion not arranged row of pits on the recording track, and the signal
The recording track and the adjacent No. pit column provided no part
An optical disc reproducing apparatus in which pit rows of the recording tracks are arranged on both sides of the inner and outer peripheries of the optical disc. And a control unit for stopping the subsequent reproduction when the reproduction signal is the same each time.