JP2011170907A - Optical disk, optical disk device, contents reproducing system, and content reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayered optical disk, an optical disk device, a content reproduction system, and a content reproduction method, which achieve both the protection of the copyright of a content and user friendliness. <P>SOLUTION: Content data are recorded on the ROM layer 22 of the optical disk 2, and essential data showing a file system for managing the content data are recorded on an RE layer 21. A CPU 10 reads the content data using the essential data. Thereafter, the content is reproduced on the basis of the read content data. Next, the number of times of using the content data recorded on the RE layer 21 is incremented by the CPU 10. When the number of times of using after the increment is not smaller than the predetermined upper limit thereof, the essential data recorded on the RE layer 21 are deleted. As a result of this, it becomes impossible to read the content data. However, writing the previously backed-up essential data back onto the RE layer 21 makes it possible to read again. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a multi-layer type optical disc, an optical disc apparatus that reproduces content based on content data, a content reproduction system, and a content reproduction method.

The optical disc apparatus reads and writes data from and on an optical disc such as a DVD (Digital Versatile Disc) and / or a BD (Blu-ray Disc (registered trademark)) mounted on the optical disc apparatus.
In recent years, a multi-layer optical disc (so-called hybrid disc) in which a data rewritable recording layer (hereinafter referred to as RE layer) and a read-only recording layer (hereinafter referred to as ROM layer) are laminated has been proposed. ing. For example, content data indicating content such as a movie or a game is recorded in advance in the ROM layer, and various data generated when the content is reproduced is read from and written to the RE layer.

When such a multi-layer optical disk is used, there is no need to store content data and various data in a storage device built in the optical disk apparatus. For this reason, the multi-layer type optical disc is particularly suitable for use in a mobile optical disc apparatus having a small storage capacity.
By the way, in order to protect copyrights such as images or music, it is necessary to prevent unlimited use of data recorded on the optical disc.

  Conventionally, there has been proposed an optical disc apparatus that deletes data recorded on an optical disc or destroys a recording surface on which data is recorded when the number of times of using data reaches a predetermined upper limit number. (See Patent Documents 1 to 4). In such an optical disc apparatus, data to be used is lost, so that the number of data use can be limited to the upper limit.

  When video data is received, the received video data is encrypted with the encryption key generated by itself and then recorded on the video tape. After a predetermined time has elapsed since the generation of the encryption key, the encryption key is There has been proposed a recording / playback apparatus that deletes (see Patent Document 5). In such a recording / playback apparatus, the video data cannot be decrypted without the encryption key, and therefore, the valid period of the video data can be limited to a predetermined time after the encryption key is generated. it can.

JP-A-8-147856 JP-A-9-231612 JP-A-11-144379 Japanese Patent Laid-Open No. 2001-67731 Japanese Patent Laid-Open No. 11-232776

However, Patent Documents 1 to 5 do not describe technical matters for limiting the number of times of use or effective period of content data recorded on the ROM layer of a multi-layer type optical disc.
In addition, the optical disc apparatuses described in Patent Documents 1 to 4 are not suitable when it is desired to limit the number of times content data is used or the validity period without losing the content data itself.
Furthermore, the recording / playback apparatus described in Patent Document 5 stores the encryption key therein. For this reason, even within the valid period of the video data, the video data cannot be decoded by another recording / playback apparatus, which is inconvenient.

  The present invention has been made in view of such circumstances, and its main purpose is a first recording layer in which essential data essential for use of content data is recorded, and a second in which content data is recorded in advance. An object of the present invention is to provide a multi-layer type optical disc, an optical disc apparatus, a content reproduction system, and a content reproduction method capable of achieving both copyright protection of content and user convenience by laminating recording layers. .

  The optical disc according to the present invention is an optical disc in which a first recording layer in which data is recorded and a read-only second recording layer in which content data indicating content is recorded in advance are laminated. Is recorded with essential data essential for use of the content data recorded in the second recording layer.

  The optical disc according to the present invention is characterized in that the essential data indicates a file system for managing the content data.

  In the optical disc according to the present invention, the content data is encrypted, and the essential data indicates a decryption key for decrypting the content data.

  The optical disk according to the present invention is characterized in that the essential data indicates permission / denial information indicating permission or prohibition of use of the content data.

  An optical disc apparatus according to the present invention is equipped with an optical disc in which a first recording layer in which data is recorded and a read-only second recording layer in which content data indicating content is recorded in advance are stacked. In an optical disc apparatus comprising a reproducing means for reproducing content based on content data recorded on the second recording layer of the optical disc, a reading means for reading data recorded on the first recording layer, and the reading means An essential determination means for determining whether or not the read data is indispensable data essential for use of the content data, and whether or not a predetermined condition that means prohibition of use of the content data is satisfied And determining that the condition determining means is satisfied, and determining that the essential determining means is essential data. A revoking unit that invalidates the essential data recorded in the first recording layer, and the reproducing unit reproduces the content when the essential determining unit determines that the essential data is essential data. It is made to do so.

  In the optical disc apparatus according to the present invention, the invalidation means deletes the essential data recorded in the first recording layer or changes the essential data to data different from the essential data in a predetermined change procedure. Alternatively, the essential data is invalidated by destroying the first recording layer.

  The content playback system according to the present invention includes an optical disc in which a first recording layer in which data is recorded, and a read-only second recording layer in which content data indicating content is recorded in advance, and the optical disc A content playback system comprising: an optical disk device having a playback means for playing back content based on content data recorded on the second recording layer of the mounted optical disk; Reading means for reading data recorded in the recording layer, essential determination means for determining whether the data read by the reading means is essential data for use of the content data, A condition determination hand that determines whether or not a predetermined condition that means prohibition of use is established. And invalidating the essential data recorded in the first recording layer when it is determined that the condition determining unit is established and the essential determining unit determines that the essential data is required. And the reproduction means reproduces the content when the essential determination means determines that the data is essential.

  The content reproduction system according to the present invention is characterized by further comprising a data recording device on which the optical disc is mounted and the essential data is recorded on the first recording layer of the mounted optical disc.

  The content playback method according to the present invention includes a first recording layer in which data is recorded, a read-only second recording layer in which content data indicating content is recorded in advance, and the optical disc In a content reproduction system comprising: an optical disk device to be mounted; and a content reproduction method for reproducing content based on content data recorded on a second recording layer of an optical disk mounted on the optical disk device. When the data recorded in the recording layer is read, and the read data is essential data essential for use of the content data, the content is reproduced, and the essential data is recorded in the first recording layer And when the use of the content data is prohibited, the first recording layer And wherein the invalidating the essential data recorded.

In the present invention, a multi-layer optical disc is formed by laminating a first recording layer and a second recording layer. Content data is recorded in advance in the second recording layer. In the first recording layer, essential data essential for using the content data recorded in the second recording layer is recorded at an appropriate timing (for example, at the time of manufacturing an optical disc).
The optical disc apparatus according to the present invention executes a reproduction process by a reproduction unit, a read process by a read unit, an essential determination process by an essential determination unit, a condition determination process by a condition determination unit, and an invalidation process by an invalidation unit. A content playback system including such an optical disk device and a multi-layer optical disk, that is, a content playback system according to the present invention realizes the content playback method according to the present invention.

When the essential data is recorded on the first recording layer of the optical disc, the reading means of the optical disc apparatus reads the data recorded on the first recording layer.
Next, the essential determination means determines whether or not the data read by the reading means is essential data. Here, the case where it is determined as essential data is a case where the reading unit can read out the essential data, and the case where it is determined as no is a case where the reading unit cannot read out the essential data. is there.

When the reading unit can read the essential data, the reproducing unit reproduces the content based on the content data recorded on the second recording layer.
When the reading unit cannot read the essential data, the reproducing unit cannot reproduce the content based on the content data recorded on the second recording layer.

  The condition determining means determines whether or not a predetermined condition is established. Here, the case where it is determined that the predetermined condition is satisfied is the case where the use of the content data is prohibited, and the case where it is determined that the use is not permitted means that the use of the content data is permitted. Is the case. Specific examples of the predetermined condition include, for example, that the usage count of the content data is greater than or equal to a predetermined upper limit count, or that the usage date and time of the content data is outside a predetermined effective period.

  When the use of the content data is prohibited, the invalidating unit invalidates the essential data recorded on the first recording layer. In other words, when the use of the content data is permitted, the invalidation process by the invalidation unit is not executed. Therefore, the content can be reproduced. Then, after executing the invalidation process by the invalidating means, it becomes impossible to reproduce the content. This is because the reading means cannot read out the essential data when the essential data is invalidated.

In the present invention, the essential data indicates a file system, a decryption key, and / or permission / rejection information.
When the essential data indicates a file system for managing content data recorded in the second recording layer, the content data cannot be read from the second recording layer when the file system is invalidated. Therefore, it is impossible to reproduce the content by the reproducing means. On the other hand, when the content is not invalidated, the content data can be read, so that the content can be reproduced by the reproducing means.

  When the essential data indicates a decryption key for decrypting encrypted content data, if the decryption key is invalidated, even if the content data can be read from the second recording layer The read content data cannot be decrypted. Therefore, it is impossible to reproduce the content by the reproducing means. On the other hand, when the content is not invalidated, the content data can be decrypted, so that the content can be reproduced by the reproducing means.

  When the essential data indicates permission / prohibition information indicating permission or prohibition of use of the content data, when the permission / rejection information is invalidated, it is not possible to determine whether the use is permitted or not based on the permission / rejection information. Further, if the permission / refusal information means permission to use the content data, use of the content data recorded in the second recording layer is prohibited when the permission / refusal information is invalidated. It can be said. Therefore, it is impossible to reproduce the content by the reproducing means. On the contrary, when the permission / prohibition information indicating permission of use of the content data is not invalidated, the use of the content data is permitted, so that the content can be played back by the playback means.

  From the above, it is possible to easily limit the number of times the content data is used or the validity period, etc., by any one or a combination of the file system, the decryption key, and the permission information.

In the present invention, when the use of content data is prohibited, the invalidation means deletes the essential data, changes the essential data, or destroys the first recording layer.
If the essential data recorded on the first recording layer is deleted, the reading means cannot read the essential data. Therefore, it is impossible to reproduce the content by the reproducing means.
However, in this case, the first recording layer is not physically destroyed. Therefore, for example, if the essential data backed up in the external storage device is written back to the first recording layer, the reading means can read the essential data. Therefore, the content can be reproduced by the reproducing means.

If the essential data recorded in the first recording layer is changed to data different from the essential data by a predetermined changing procedure, the reading means cannot read the essential data. Therefore, it is impossible to reproduce the content by the reproducing means.
However, in this case, the first recording layer is not physically destroyed. Therefore, for example, if the changed data is changed again to the essential data before the change based on a predetermined change procedure, the reading means can read the essential data. Therefore, the content can be reproduced by the reproducing means.

  As described above, when the essential data is invalidated by deleting the essential data or changing the essential data, permission / prohibition of use of the content data can be switched as appropriate. Even if the use of content data is prohibited, by reusing the first recording layer, the optical disc of the present invention can be effectively used in the same manner as a general optical disc capable of writing data.

On the other hand, if the first recording layer is destroyed, the reading means cannot read essential data. Therefore, it is impossible to reproduce the content by the reproducing means.
In this case, since the first recording layer cannot be returned to the state where the essential data is recorded, the unlimited use of the content data can be further reliably suppressed.

In the present invention, the data recording device records the essential data on the first recording layer of the optical disc mounted on the data recording device.
An optical disc in which essential data is invalidated is in a state in which content cannot be reproduced. At this time, by recording the essential data on the first recording layer using the data recording device, the optical disc in which the content cannot be reproduced can be returned to the state in which the content can be reproduced.

  However, an optical disc that can be restored from a state in which content cannot be reproduced can write essential data to the first recording layer (that is, the first recording layer is not destroyed and the first recording layer is not destroyed). The free space is equal to or greater than the amount of required data).

According to the optical disc, the optical disc apparatus, the content reproduction system, and the content reproduction method of the present invention, it is possible to achieve both content copyright protection and user convenience by using the first recording layer of the multi-layer type optical disc. .
This is because, when the use of content data is prohibited, the essential data recorded on the first recording layer is invalidated, so that the content cannot be reproduced on the optical disc apparatus. In addition, at this time, the content data recorded on the second recording layer is not invalidated. Accordingly, it is possible to limit the number of times the content data is used or the validity period without losing the content data itself.

  Further, when the use of the content data is permitted, the content data and the essential data are recorded on the same optical disc. Therefore, until the use of the content data is prohibited, the content is stored on a different optical disc device. Can be played. In other words, the optical disc apparatus that can reproduce the content is not limited.

It is a block diagram which shows the principal part structure of the content reproduction system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the principal part structure of the disk drive with which the optical disk apparatus which concerns on Embodiment 1 of this invention is provided. It is a block diagram which shows the principal part structure of PC (personal computer) with which the content reproduction system which concerns on Embodiment 1 of this invention is provided. It is a flowchart which shows the procedure of the data recording process performed with PC provided with the content reproduction system which concerns on Embodiment 1 of this invention. 6 is a flowchart showing a procedure of content reproduction processing executed by the optical disc apparatus according to Embodiment 1 of the present invention. It is a flowchart which shows the procedure of the content reproduction process performed with the optical disk apparatus based on Embodiment 2 of this invention. It is a flowchart which shows the procedure of the content reproduction process performed with the optical disk apparatus based on Embodiment 3 of this invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

Embodiment 1.
FIG. 1 is a block diagram showing a main configuration of a content reproduction system 6 according to Embodiment 1 of the present invention. The content reproduction system 6 includes an optical disc device 1, an optical disc 2, and a PC 5.
FIG. 2 is a block diagram showing a main configuration of the disk drive 3 included in the optical disk apparatus 1.
The optical disc apparatus 1 is a stationary BD player that complies with the BD standard. As shown in FIG. 1, the optical disc apparatus 1 includes an apparatus main body 15 and a remote controller (remote controller) 16 separate from the apparatus main body 15.

A user of the optical disc apparatus 1 operates the optical disc apparatus 1 by pressing various operation buttons (not shown) of the remote controller 16. When the operation button is pressed, the remote controller 16 transmits an operation signal corresponding to the pressed operation button to the optical disc apparatus 1 by a communication method such as an infrared method or an RF method.
The apparatus main body 15 of the optical disc apparatus 1 includes a CPU 10, a ROM 11, a RAM 12, a reproducing unit 13, a receiving unit 14, and a disc drive 3.
The CPU 10 is a control center of the optical disc apparatus 1. The CPU 10 uses the RAM 12 which is a readable / writable volatile memory as a work area, controls each part of the apparatus main body 15 according to a computer program stored in the ROM 11 which is a read-only nonvolatile memory, and executes various processes.

The receiving unit 14 receives the operation signal and outputs the received operation signal to the CPU 10.
When the optical disc apparatus 1 is a portable BD player, the apparatus main body 15 may be provided with an operation unit instead of the receiving unit 14 and the remote controller 16. The user operates the optical disc apparatus 1 by pressing various operation buttons of the operation unit. When the operation button is pressed, the operation unit outputs an operation signal corresponding to the pressed operation button to the CPU 10.
The playback unit 13 is for playing back content, and content data indicating the content is input. In the present embodiment, a movie having a moving image and sound is exemplified as the content. The content is not limited to a movie, and may be a still image, a game, an operating system, or the like.

The playback unit 13 is connected to an external television device (not shown). This television apparatus includes a liquid crystal panel that displays a moving image and a speaker that outputs sound.
When content data is input, the reproduction unit 13 separates moving image data indicating a moving image and audio data indicating sound from the input content data. Next, the playback unit 13 transmits the moving image data and the sound data to the television device while maintaining the synchronization between the separated moving image data and the sound data.
As a result, in the television apparatus, a movie moving image is displayed on the liquid crystal panel, and the movie sound is output from the speaker.

  When the content data is encrypted, the reproduction unit 13 is also supplied with the decryption key data corresponding to the content data together with the content data. In this case, the playback unit 13 decrypts the encrypted content data using the decryption key data.

When the optical disc apparatus 1 is a portable BD player, the playback unit 13 includes a liquid crystal panel (not shown) that displays a moving image and a speaker (not shown) that outputs sound.
In this case, when content data is input, the playback unit 13 separates moving image data and audio data from the input content data. Next, the reproduction unit 13 provides the moving image data to the liquid crystal panel and the sound data to the speaker while maintaining the synchronization between the separated moving image data and the sound data.
As a result, in the optical disc apparatus 1, the movie moving image is displayed on the liquid crystal panel, and the movie sound is output from the speaker.

The disk drive 3 includes a disk tray 30, a spindle motor 31, a drive control unit 32, a signal processing unit 33, a data detection unit 34, and an optical pickup 4.
The drive control unit 32 controls each unit of the disk drive 3 under the control of the CPU 10. In other words, the CPU 10 indirectly controls each unit of the disk drive 3 via the drive control unit 32.

  The disc tray 30 is accompanied by a tray raising / lowering mechanism (not shown) for making the disc tray 30 appear and disappear with respect to the apparatus main body 15. The CPU 10 causes the disk tray 30 to protrude from the apparatus main body 15 by operating the tray retracting mechanism via the drive control unit 32, or causes the disk tray 30 to enter the apparatus main body 15. For example, when the user presses an eject button provided on the remote controller 16, the disc tray 30 is switched on and off.

The optical disc 2 is detachably mounted on the disc tray 30. The user mounts the desired optical disk 2 on the disk tray 30 or replaces the optical disk 2 placed on the disk tray 30 with the desired optical disk 2.
The spindle motor 31 rotates the optical disc 2 mounted on the disc tray 30 by being controlled by the drive control unit 32 when the disc tray 30 is accommodated in the apparatus main body 15.

Here, the configuration of the optical disc 2 will be described with reference to FIGS. 1 and 2.
The optical disc 2 is formed by laminating a RE (Rewritable) layer 21 and a ROM (Read Only Memory) layer 22 in this order on one surface of the circular substrate 20 (the lower surface in FIG. 2). The lower surface of the RE layer 21 is a recording surface on which data can be rewritten, and the lower surface of the ROM layer 22 is a read-only recording surface on which data is recorded in advance. Here, the RE layer 21 and the ROM layer 22 function as the first recording layer and the second recording layer in the embodiment of the present invention.

On the recording surfaces of the RE layer 21 and the ROM layer 22, a plurality of concentric tracks are formed at regular pitches. Each track uses, for example, a recording groove (wobble groove) that meanders regularly, and data is written at the bottom of the recording groove. Further, the write / read position of data is positioned (addressed) by using meandering of the recording groove.
The configuration of the optical disk 2 is not limited to such a configuration. For example, one track may be formed in a spiral shape, LPP may be formed on a convex portion (land) between adjacent recording grooves, and positioning may be performed using LPP.

Further, in the optical disc 2 in the present embodiment, the RE layer 21 and the ROM layer 22 are stacked one by one, but one or both of the RE layer 21 and the ROM layer 22 may be stacked. Furthermore, the stacking order of the RE layer 21 and the ROM layer 22 may be reversed.
Hereinafter, the recording surface to which data is read / written out of the recording surface of the RE layer 21 and the recording surface of the ROM layer 22 is referred to as a recording / reproduction target. Further, when the recording surface of the RE layer 21 and the recording surface of the ROM layer 22 are not distinguished, they are referred to as the lower surface of the optical disc 2.

The optical pickup 4 irradiates the rotating optical disc 2 with a light beam, converts the light beam reflected by the optical disc 2 into an electrical signal, and outputs the electrical signal to the signal processing unit 33.
More specifically, as shown in FIG. 2, the optical pickup 4 includes an objective lens mechanism 41, a quarter wavelength plate 42, a spherical aberration correction mechanism 43, a polarization beam splitter 44, a diffraction grating 45, a light source 46, and a light receiving optical system. 47 and a light detection unit 48.
Among the parts constituting the optical pickup 4, the objective lens mechanism 41 is disposed at a position closest to the lower surface of the optical disc 2.

The objective lens mechanism 41 includes an objective lens 411 for condensing the light beam on the lower surface of the optical disc 2 and an objective lens actuator 412.
The optical axis direction of the objective lens 411 (hereinafter simply referred to as the optical axis direction) coincides with the focusing direction of the objective lens 411 and is along the normal direction of the lower surface of the optical disc 2.
The objective lens actuator 412 is controlled by the drive control unit 32 to move the objective lens 411 in the focusing direction (that is, the direction in which the objective lens 411 is moved toward or away from the optical disc 2) or the tracking direction.

  More specifically, the objective lens 411 is a molded aspherical single lens and has a high NA of NA (Numerical Aperture) 0.85. The objective lens actuator 412 is, for example, a magnet-type biaxial actuator, and includes an elastic body that supports the objective lens 411, and a magnet and a coil for driving the objective lens 411. Such an objective lens actuator 412 moves the objective lens 411 in the focusing direction or the tracking direction by energizing the coil.

The light source 46 outputs a light beam in the direction of the optical axis so as to irradiate the lower surface of the optical disc 2 rotated by the spindle motor 31 with the light beam. Specifically, the light source 46 uses, for example, an LD (Laser Diode) containing an In (indium) mixed crystal of GaN (gallium nitride), and oscillates a laser beam having a wavelength of 405 nm.
On the optical axis of the objective lens 411 and between the objective lens mechanism 41 and the light source 46, from the light source 46 side to the objective lens mechanism 41 side, a diffraction grating 45, a polarization beam splitter 44, a spherical aberration correction mechanism 43, and The quarter wavelength plate 42 is arranged in this order.

The light beam output from the light source 46 first passes through the diffraction grating 45. The diffraction grating 45 is an optical element for optimizing the light beam incident on the objective lens 411.
The light beam that has passed through the diffraction grating 45 passes through the polarization beam splitter 44.
The spherical aberration correction mechanism 43 is a correction mechanism for correcting spherical aberration that changes as the position of the objective lens 411 changes, that is, spherical aberration that changes as the focus position changes. Specifically, the spherical aberration correction mechanism 43 includes a collimating lens 431, a frame portion 432, support shafts 433, 433,..., And a collimating lens driving motor 434.

The frame portion 432 is provided at the peripheral edge of the collimating lens 431, and the support shafts 433, 433,... Support the frame portion 432 so that the collimating lens 431 can move in the optical axis direction. Then, the collimator lens drive motor 434 is controlled by the drive control unit 32 to move the frame portion 432 and, in turn, the collimator lens 431 in the optical axis direction.
The light beam that has passed through the polarization beam splitter 44 passes through the collimator lens 431 from the lower side to the upper side.
The light beam whose spherical aberration is corrected by passing through the collimating lens 431 is then passed from the lower side to the upper side through the quarter-wave plate 42 to change from a linearly polarized light beam to a circularly polarized light beam. Converted.

The light beam that has passed through the quarter-wave plate 42 passes through the objective lens 411 from the lower side to the upper side, and then enters the lower surface of the optical disc 2.
The lower surface of the optical disc 2 reflects the incident light beam. At this time, the reflected light beams include those reflected by the recording / reproducing object and those reflected by the recording surface other than the recording / reproducing object.
The reflected light beam first passes through the objective lens 411 from the upper side to the lower side, and then passes through the quarter wavelength plate 42 from the upper side to the lower side, so that the circularly polarized light beam is converted into the linearly polarized light beam. Converted into a light beam.

The light beam that has passed through the quarter-wave plate 42 passes through the collimator lens 431 from the upper side to the lower side, and is then refracted by the polarization beam splitter 44 in a direction that intersects the optical axis direction. As described above, the polarization beam splitter 44 separates the light beam to be incident on the optical disc 2 and the light beam reflected by the optical disc 2.
The light beam refracted by the polarization beam splitter 44 enters the light receiving optical system 47.
The light beam incident on the light receiving optical system 47 is separated into a light beam reflected by a recording / reproducing object and a light beam reflected by a recording surface other than the recording / reproducing object. For this purpose, the light receiving optical system 47 includes, for example, a hologram element.

Among the separated light beams, for example, astigmatism is given to the light beam reflected by the recording / reproducing object. For this purpose, the light receiving optical system 47 includes a cylindrical lens.
Thereafter, the light beam reflected by the recording / reproducing object enters the light detection unit 48.

The light detection unit 48 uses a PD (Photo Diode) that photoelectrically converts the light beam reflected by the recording / reproduction target. More specifically, the light receiving surface of the light detection unit 48 is divided into four equal parts into four detection surfaces by two virtual line segments orthogonal to each other with the optical axis of the light beam incident thereon as an intersection. A plurality of PDs are arranged on each of the four equal detection surfaces. As a result, when a light beam is incident on each detection surface, four electrical signals corresponding to the intensity of the light beam received by each detection surface are output to the signal processing unit 33.
The optical pickup 4 as described above is supported by a guide rail (not shown) and is configured to move in the radial direction of the optical disc 2 when an optical pickup drive motor (not shown) controlled by the drive control unit 32 is operated. Has been.

The signal processing unit 33 generates an RF (Radio Frequency) signal, a TE (Tracking Error) signal, and an FE (Focus Error) signal based on the four input electric signals, and generates the generated RF signal, TE signal, And the FE signal are output to the drive control unit 32. For this purpose, the signal processing unit 33 generates, for example, an RF signal having a voltage level equal to the result of adding the voltage levels of the four input electric signals.
The RF signal indicates whether or not meaningful data (for example, content data or essential data to be described later, hereinafter referred to as recording data) is recorded at the incident position of the light beam in the recording / reproducing target, When recording data is recorded, it indicates the contents of the recorded recording data.

The TE signal indicates a positional deviation in the radial direction of the optical disc 2 between the tracking position of the light beam on the recording / reproducing target and the track formed on the recording / reproducing target.
The FE signal indicates a positional shift in the normal direction of the optical disc 2 between the focus position of the light beam and the recording / reproduction target.
The drive control unit 32 controls the objective lens actuator 412 and the collimating lens driving motor 434 of the optical pickup 4 based on the input RF signal, TE signal, and FE signal. As a result, the tracking position, focus position, spherical aberration and the like related to the optical pickup 4 are adjusted to appropriate positions.

  The optical pickup 4 is configured such that, of the light beams separated by the light receiving optical system 47, the light beam reflected by the recording surface other than the recording / reproducing target is incident on a light detection unit other than the light detection unit 48. It may be. The light detection unit is configured in the same manner as the light detection unit 48, and the four electrical signals output from the light detection unit are also output to the signal processing unit 33. In this case, the signal processing unit 33 generates an RF signal, a TE signal, and an FE signal based on a total of eight input electrical signals. At this time, the adjustment of the tracking position, the focus position, and the like by the drive control unit 32 is performed more accurately.

Further, the drive control unit 32 outputs the input RF signal to the data detection unit 34.
The data detection unit 34 to which the RF signal is input has no meaning based on the input RF signal and indicates that the recording data recorded in the recording / reproduction target or that the recording data is not recorded in the recording / reproduction target The correct data. For this purpose, the data detection unit 34 includes an AD conversion unit that AD converts an RF signal that is an analog signal, a limit equalizer, a demodulation unit, an error correction unit, and the like for detecting various data from the digital signal after AD conversion. I have.

  Note that the drive control unit 32 may have some of the functions of the data detection unit 34. Further, the drive control unit 32 and the data detection unit 34 may be configured as a single chip.

Various data detected by the data detection unit 34 is temporarily stored in the RAM 12 (see FIG. 1), and then read from the RAM 12 to be input to the CPU 10 and / or the reproduction unit 13.
As described above, in the optical disc apparatus 1, the recording data read from each of the RE layer 21 and the ROM layer 22 is used without being installed in a mass storage device such as an HDD (hard disk).
Next, recording data read from and written to the optical disc 2 will be described.

At least content data is recorded on the recording surface of the ROM layer 22 (hereinafter simply referred to as the ROM layer 22). In addition to the content data, various recording data are recorded in the ROM layer 22.
For example, the ROM layer 22 stores data of a file system for managing the recording surface of the RE layer 21 (hereinafter simply referred to as the RE layer 21) and the recording data recorded on the ROM layer 22. The file system is FAT or HFS.
When content data recorded in the ROM layer 22 (hereinafter simply referred to as content data) is encrypted, the ROM layer 22 stores data of a decryption key for decrypting the content data. .

However, as will be described later, when the file system data and / or the decryption key data is used as the essential data according to the embodiment of the present invention, the essential data is recorded in the RE layer 21 and the ROM layer 22. Is not recorded.
Hereinafter, a case where the optical disc 2 is a rental product will be described. In order to protect the copyright of the movie indicated by the content data, the present embodiment exemplifies a case where the number of times content data is used is limited to a predetermined upper limit number (specifically, once).

The frequency data indicating the number of times of using the content data is recorded in the RE layer 21. In the present embodiment, the number of uses is incremented by “1” when the content is played back.
Since the upper limit number is 1, the number data indicating that the number of use is 0 (hereinafter referred to as the number data “0”) functions as permission / inhibition information indicating permission to use the content data. In addition, the number data indicating that the number of times of use is one or more (hereinafter referred to as the number data “1”) functions as permission / prohibition information indicating prohibition of use of the content data. In the case where the count data “0” and the count data “1” are not distinguished, they are simply referred to as count data below.

As shown in FIG. 1, the optical disc apparatus 1 is installed in a user's home H. The user borrows the optical disc 2 from the rental company at the rental shop S. In the rental shop S, a PC 5 used by a rental company is installed.
FIG. 3 is a block diagram showing a main configuration of the PC 5.
The PC 5 uses a general personal computer, and includes a CPU 50, a ROM 51, a RAM 52, an HDD 53, a display unit 54, an operation unit 55, and a disk drive 56.
The HDD 53 stores various computer programs and data.

The CPU 50 is a control center of the PC 5. The CPU 50 uses the RAM 52 as a work area, controls each part of the PC 5 according to a computer program stored in the ROM 51, and executes various processes.
The display unit 54 uses a liquid crystal display, and the operation unit 55 uses a keyboard and a mouse.
The disc drive 56 is loaded with the optical disc 2 returned from the user. In the RE layer 21 of the optical disc 2, the count data “1” is recorded, and the essential data is not recorded.

  The rental company records the count data “0” in the RE layer 21 before lending the optical disc 2 to the user. Furthermore, the rental company records essential data necessary for using the content data in the RE layer 21. For this purpose, the rental company keeps backup data of essential data outside the optical disc 2. Specifically, the backup data is stored in the HDD 53 of the PC 5.

Here, the recording of the essential data means that the essential data read from the outside of the optical disc 2 is written in the RE layer 21. The recording of the number data “0” means that the number data “1” recorded in the RE layer 21 is rewritten to the number data “0”.
In order to record the essential data and the count data “0” in the RE layer 21, the rental company operates the operation unit 55 while visually checking the display unit 54 of the PC 5, thereby performing the data recording process shown in FIG. Is executed.

  FIG. 4 is a flowchart showing a procedure of data recording processing executed by the PC 5. This data recording process is executed when the optical disk 2 is loaded in the disk drive 56. A computer program for causing the CPU 50 to execute data recording processing may be recorded on the optical disc 2 or may be stored in the HDD 53.

The CPU 50 determines whether or not essential data is recorded in the RE layer 21 of the optical disk 2 mounted in the disk drive 56 (S51). If it is not recorded (NO in S51), the CPU 50 requires it from the HDD 53. Data is read (S52) and written to the RE layer 21 (S53).
After the processing of S53 is completed or when essential data is recorded in the RE layer 21 (YES in S51), the CPU 50 determines whether or not the count data “0” is recorded in the RE layer 21 (S54). If not recorded (NO in S54), the number data “1” is rewritten to the number data “0” (S55).

After the process of S55 is completed or when the count data “0” is recorded in the RE layer 21 (YES in S54), the CPU 50 automatically ejects the optical disc 2 (S56), and then performs the data recording process. finish.
Note that copying of essential data from the HDD 53 to the RE layer 21 and / or rewriting of the count data “1” to the count data “0” may be manually executed by the rental agent.

In this embodiment, a case where data of a file system is used as essential data is exemplified. As will be described later, the essential data is deleted when the content is reproduced, that is, when the count data “0” is rewritten to the count data “1”.
In addition, deletion of essential data in the present embodiment means that data different from essential data is overwritten in a recording area where the essential data is recorded. In this case, unauthorized recovery of essential data remaining in the RE layer 21 is prevented.

If the data in the file system is deleted, the optical disk apparatus 1 cannot read the content data, and cannot read or write the data recorded in the RE layer 21. As a result, if the essential data is deleted, the content cannot be reproduced.
By the way, even if the data of the file system is deleted, the optical disk 2 can be set in the disk drive 56 built in the rental company's PC 5 and the RE layer 21 can be forcibly accessed. Accordingly, the rental company that stores the backup data of the file system can write the file system data in the RE layer 21 using the PC 5.

The essential data is preferably recorded in a predetermined recording area in the recording area of the RE layer 21. The predetermined recording area is preferably located in the focus adjustment area used when adjusting the focus position, spherical aberration, and the like related to the optical pickup 4 or in the vicinity of the focus adjustment area. In this case, the time required for reading the essential data is shortened as compared with the case where the essential data is recorded outside the predetermined recording area.
As described above, the PC 5 that executes the data recording process functions as the data recording apparatus according to the embodiment of the present invention.

  In addition, in the optical disc 2 distributed from the manufacturer to the rental company, the essential data and the frequency data “0” are recorded in the RE layer 21 in advance, but the present invention is not limited to this. For example, the optical disc 2 in which the essential data is not recorded in the RE layer 21 and a recording medium in which the essential data is recorded (for example, an optical disc other than the optical disc 2 or a nonvolatile memory device) may be distributed as a set. .

  FIG. 5 is a flowchart showing a procedure of content reproduction processing executed in the optical disc apparatus 1. The content reproduction process is executed when the optical disc 2 is mounted on the disc tray 30. A computer program for causing the CPU 10 to execute content reproduction processing may be recorded on the optical disc 2 or may be stored in the ROM 11.

The CPU 10 attempts to read out essential data from the RE layer 21 (S11). Each unit of the CPU 10 and the disk drive 3 in S11 functions as a reading unit in the embodiment of the present invention.
Next, the CPU 10 determines whether or not the essential data has been read (S12). The CPU 10 in S12 functions as an essential determination unit in the embodiment of the present invention.

If the essential data cannot be read (NO in S12), that is, if the data that can be read from the RE layer 21 in the process of S11 is only data different from the essential data (for example, meaningless data), the CPU 10 An error is notified to (S13). For this purpose, the CPU 10 outputs data for displaying a message indicating that reproduction of content is not permitted to an external television device to the reproduction unit 13.
After the process of S13 is completed, the CPU 10 automatically ejects the optical disc 2 (S14), and then ends the content reproduction process.

  When the essential data can be read (YES in S12), the CPU 10 reads the count data from the RE layer 21 (S15), and determines whether the read count data is the count data “1” (S16). The CPU 10 in S16 functions as a condition determination unit in the embodiment of the present invention, and that the read number data is “1” indicates that a predetermined condition that means prohibition of use of content data is established. It corresponds to being.

  If the count data read in S15 is the count data “1” (YES in S16), it is said that the essential data has not been deleted even though the use of the content data and the reproduction of the content are prohibited. There is an inconvenience. For this reason, the CPU 10 deletes the essential data recorded in the RE layer 21 (S17), and moves the process to S13. Each unit of the CPU 10 and the disk drive 3 in S17 functions as invalidating means in the embodiment of the present invention.

  When the count data read in S15 is the count data “0” (NO in S16), content reproduction is permitted. Therefore, the CPU 10 reads the content data from the ROM layer 22 (S18), and outputs the read content data to the playback unit 13, thereby playing back the content (S19). Each unit of the CPU 10 and the disk drive 3 in S19 functions as a reproducing unit in the embodiment of the present invention.

Then, the CPU 10 determines whether or not the content reproduction has ended (S20), and if it has not ended (NO in S20), the process returns to S18.
Here, the case where the reproduction of the content is completed is, for example, a case where the movie is reproduced from the beginning to the end. If the movie playback is interrupted, it may not be considered that the content playback has ended. At this time, if data indicating where the movie was played from where to where is written in the RE layer 21, the user can view the unplayed part again at a later date.

By the way, in the present embodiment, since the upper limit number is one, the CPU 10 in S20 functions as the condition determination means in the embodiment of the present invention, and the end of the content reproduction is the use of the content data. This corresponds to the establishment of a predetermined condition meaning prohibition.
However, if the upper limit number is N (N is a natural number of N ≧ 2) times, a process of determining whether or not the number of uses indicated by the number data is N or more is executed after the process of S21 to be described later. This process is necessary, and this process functions as a condition determination process by the condition determination means. In this case, the usage count indicated by the frequency data is equal to or more than N times, which corresponds to the establishment of a predetermined condition that means prohibition of the usage of the content data.

When the reproduction of the content is completed (YES in S20), the CPU 10 rewrites the count data “0” to the count data “1” (S21). That is, the CPU 10 increments the usage count indicated by the count data by “1”.
Next, the CPU 10 deletes the essential data recorded in the RE layer 21 (S22), and moves the process to S14. Each unit of the CPU 10 and the disk drive 3 in S22 functions as an invalidating unit in the embodiment of the present invention.

  The optical disc apparatus 1 as described above can limit the number of times content data is used to a maximum number of times or less by deleting essential data recorded in the RE layer 21 under predetermined conditions. Can protect the copyright. In addition, while the essential data is recorded in the RE layer 21, the content data can be used in different optical disk devices 1, 1,..., And if the essential data is written back to the RE layer 21, the ROM layer 22 can be used. Since the content data recorded in the file can be used again, user convenience can be improved.

The optical disc apparatus 1 is not limited to a configuration that uses only file system data as essential data. That is, the optical disc apparatus 1 may be configured to use one or more of the file system data, the decryption key data, and the permission information data as the essential data.
If the decryption key data is deleted, the encrypted content data cannot be decrypted. Further, if the permission / rejection information data is deleted, it is determined NO in S12 shown in FIG. 5, and the processing of S18 is not executed, so that the content data cannot be read. As a result, if one or more essential data is deleted, the content cannot be reproduced.

However, when the content data is stream data, at least the decryption key data should be used as the essential data.
When the decryption key data is used as the essential data, the CPU 10 may execute the process of reading the essential data from the RE layer 21 and the process of determining whether or not the data has been read after determining NO in S16. Good.
By the way, when the data of permission / denial information is used as essential data, the CPU 10 does not need to execute the process of S21. In this case, the number data “0” is written into the RE layer 21 in the process of S55 shown in FIG.

  When two or more types of file system data, decryption key data, and permission / refusal information data are used as essential data, the number of times content data is used is more reliable than when one type of essential data is used. Can be limited to. The reason is that even if one essential data is not deleted due to some error, or even if it is illegally written after deletion, other essential data is deleted, This is because the content data cannot be used.

  The deletion of the essential data is not limited to a method of overwriting meaningless data in the recording area where the essential data is recorded. For example, the deletion of the essential data may be a technique in which identification information indicating deletion is added to the file name of the data file including the essential data in the file system. In this case, the essential data can only be read from the RE layer 21 and remains in the RE layer 21. Therefore, this method means that the essential data will be undeleted if the file name is restored in the file system unless the remaining essential data is overwritten with other data. You can also watch it.

  Further, when the data of the file system for managing the data recorded in the RE layer 21 and the data of the file system for managing the data recorded in the ROM layer 22 are different, the ROM layer 22 Only the file system data may be used as essential data. In this case, since the file system data for the RE layer 21 is not deleted, the data recorded in the RE layer 21 can be read and written even if the essential data is deleted.

Since the optical disc apparatus 1 according to the present embodiment reproduces content based on the content data read from the optical disc 2, the number of times content data is used in the optical disc apparatus 1 is equal to the number of times content is reproduced in the optical disc apparatus 1. .
However, the optical disc apparatus 1 may be configured to install content data read from the optical disc 2 in an internal HDD (not shown) and reproduce the content based on the content data read from the internal HDD. In this case, when the content data is installed, the usage count of the content data is incremented. Therefore, the number of uses and the number of playbacks may be different.

Here, a case where the optical disk 2 is not a rental product but a purchased product will be described.
At home, for example, there is a demand for children not to watch movies during the night.
In this case, the guardian backs up indispensable data of the optical disc 2 to a PC owned by the guardian in advance. The PC owned by the guardian functions as the data recording device in the embodiment of the present invention, like the PC 5.
In the process of S15 shown in FIG. 5, instead of reading the count data, the current time is read from a built-in clock (not shown) of the optical disc apparatus 1. In the process of S16, the current time is, for example, from 9 pm to 6 am It is determined whether it is included in the time zone up to the hour. And the process of S21 and S22 is not performed.

Data indicating a time zone during which movie viewing is prohibited may be written in the RE layer 21 or may be written in the RAM 12 or an EEPROM (not shown) of the optical disc apparatus 1.
In this case, if a child tries to watch a movie in the middle of the night, the movie will not be played back, and the movie cannot be watched in the daytime. Therefore, a child who wants to watch a movie can only offer it to his / her parents. In other words, children suffer from the disadvantage that they cannot watch movies again if they keep it secret from their parents that they have broken the family rule that they should not watch movies at midnight.

Further, when the processes of S18 to S20 are being executed, when a predetermined time (for example, 1 hour) has elapsed since the start of the reproduction of the content, the CPU 10 forcibly ends the reproduction of the content and executes the processes after S21. May be. In this case, the viewing of the movie by the child is limited to a predetermined time at one time.
If the above processing is further developed, it is possible to limit the viewing of movies by children, for example, only on holidays or within one hour once a day.

Incidentally, the essential data is not limited to the configuration in which the essential data is written to the RE layer 21 outside the optical disc apparatus 1.
For example, the optical disc device 1 is connected to a server of the manufacturer of the optical disc 2 via, for example, the Internet. The guardian also purchases license information when purchasing the optical disc 2.

When the essential data cannot be read from the RE layer 21, the optical disc apparatus 1 receives the license information. The guardian inputs the license information by operating the remote controller 16. Thereafter, the optical disc apparatus 1 transmits the input license information to the server of the manufacturer of the optical disc 2. The server transmits essential data to the optical disc apparatus 1 when the license information is valid. Then, the optical disc apparatus 1 writes the received essential data to the RE layer 21. As a result, the content can be reproduced. At this time, the optical disc apparatus 1 functions as a data recording apparatus in the embodiment of the present invention.
With such a configuration, since it is not necessary for the guardian to write back the essential data using the PC, the convenience of the guardian is improved.

Embodiment 2. FIG.
The configurations of the optical disc device 1 and the optical disc 2 of the present embodiment are substantially the same as the configurations of the optical disc device 1 and the optical disc 2 of the first embodiment. However, in this embodiment, instead of deleting the essential data, the case where the number of uses of the content data is limited to a predetermined upper limit number by changing the essential data is exemplified.
Other parts corresponding to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In a predetermined first recording area of the optical disc 2, data of a file system (hereinafter referred to as a first file system) for managing recording data recorded in each of the RE layer 21 and the ROM layer 22 is recorded.
In a predetermined second recording area on the optical disc 2, data of a file system (hereinafter referred to as a second file system) for managing the recording data recorded on the RE layer 21 is recorded.

Furthermore, in the predetermined third recording area on the optical disc 2, either one of the first file system and the second file system is recorded.
The first recording area, the second recording area, and the third recording area are all provided in the RE layer 21.
Hereinafter, when the first file system and the second file system are not distinguished, they are simply referred to as a file system.
When the optical disc 2 is mounted on the disc tray 30, the CPU 10 of the optical disc apparatus 1 reads the recording data recorded in the third recording area, and manages the recording data using the file system indicated by the read recording data. .

  Therefore, if the recording data recorded in the third recording area is data of the first file system, the CPU 10 can execute reading / writing with respect to the RE layer 21 and reading from the ROM layer 22. On the other hand, if the recording data recorded in the third recording area is data of the second file system, the CPU 10 can execute reading / writing with respect to the RE layer 21 but can perform reading from the ROM layer 22. I can't.

  When the rental company lends the optical disc 2 to the user, the number data “1” recorded in the RE layer 21 is rewritten to the number data “0” using the PC 5. The rental company also uses the PC 5 to move the second file system data from the third recording area to the second recording area, and to move the first file system data from the first recording area to the third recording area. Move.

In this embodiment, a case where data of the first file system is used as essential data is exemplified. The essential data is changed when the content is reproduced, that is, when the count data “0” is rewritten to the count data “1”.
The change of the essential data in the present embodiment means that the essential data is moved from the third recording area to the first recording area, and the data different from the essential data is transferred from the second recording area to the third recording area. Means to move to. In other words, the change of the essential data in the present embodiment means that the file system data for managing the content data is changed to the file system data that cannot manage the content data.

In the present embodiment, the rental company does not need to store backup data of essential data outside the optical disc 2.
In order to prevent fraud, for example, if the license information issued by the manufacturer of the optical disc 2 is not authenticated, the data in the first file system may not be read / written.

The change of the essential data is not limited to the movement of the system file data. For example, the change of the essential data means that the CPU 10 converts the essential data into the essential data by inserting unnecessary data into a predetermined part of the essential data or encrypting the essential data. It may be rewritten to data that cannot be recognized. In this case, the rental company uses the PC 5 to restore the essential data by deleting unnecessary data from the rewritten data or decrypting the rewritten data.
As described above, it is easy for a person who knows the procedure for changing the essential data to return the changed data to the state before the change.

  By the way, when the number data “0” (that is, permission / refusal information data indicating permission to use the content data) is used as the essential data, the number data “1” (that is, prohibition of the use of the content data is prohibited). Meaning permission information data) may be used as data different from essential data. At this time, rewriting the number-of-times data “0” with the number-of-times data “1” corresponds to a change in essential data.

FIG. 6 is a flowchart showing a procedure of content reproduction processing executed in the optical disc apparatus 1. The content reproduction process is executed when the optical disc 2 is mounted on the disc tray 30. The processes of S13 to S16 and S18 to S21 shown in FIG. 6 are the same as the processes of S13 to S16 and S18 to S21 shown in FIG. 5 of the first embodiment.
The CPU 10 reads the file system data from the third recording area in the RE layer 21 of the optical disc 2 (S31). Each unit of CPU 10 and disk drive 3 in S31 functions as a reading unit in the embodiment of the present invention.

Next, the CPU 10 determines whether or not the content data recorded in the ROM layer 22 can be accessed using the file system indicated by the read data (S32). The CPU 10 in S32 functions as an essential determination unit in the embodiment of the present invention.
The case where the content data recorded in the ROM layer 22 cannot be accessed (NO in S32) is a case where the data that can be read from the RE layer 21 in the process of S31 is not essential data. In this case, the CPU 10 moves the process to S13. The CPU 10 does not have to execute the process of S14. At this time, the optical disk apparatus 1 may read / write recording data with respect to the RE layer 21.

The case where the content data recorded in the ROM layer 22 can be accessed (YES in S32) is a case where essential data can be read in the process of S31. In this case, the CPU 10 moves the process to S15 and then executes the process of S16.
The case of YES in S16 is a case where the inconvenience that the essential data has not been changed despite the use of the content data and the reproduction of the content is prohibited. In this case, the CPU 10 changes the essential data recorded in the RE layer 21 (S33), and moves the process to S13. Each unit of the CPU 10 and the disk drive 3 in S33 functions as invalidation means in the embodiment of the present invention.

  In the case of NO in S16, the CPU 10 executes the processes after S18, changes the essential data recorded in the RE layer 21 after the end of the process of S21 (S34), and moves the process to S14.

The optical disc apparatus 1 as described above can achieve the same effect as the optical disc apparatus 1 of the first embodiment by changing the essential data recorded in the RE layer 21 under predetermined conditions.
The optical disc apparatus 1 is not limited to a configuration that uses only data of the first file system as essential data. That is, the optical disc apparatus 1 may be configured to use one or more of the first file system data, the decryption key data, and the permission / rejection information data as essential data.
If the data of the decryption key is changed, the encrypted content data cannot be decrypted.

  When the count data “0” is used as essential data, the CPU 10 in S15 and S16 functions as a reading unit and an essential determination unit in the embodiment of the present invention. However, the case where NO is determined in S16 is the case where it is determined that the essential determination means is the essential data. And after the process of S21 is complete | finished, CPU10 moves a process to S14, without performing the process of S34. This is because the process of S21 functions as an invalidation process by the invalidation means in the embodiment of the present invention.

Embodiment 3. FIG.
The configurations of the optical disc device 1 and the optical disc 2 of the present embodiment are substantially the same as the configurations of the optical disc device 1 and the optical disc 2 of the first and second embodiments. However, in the present embodiment, a case where the number of uses of content data is limited to a predetermined upper limit number by destroying the RE layer 21 is exemplified.
For this purpose, the light source 46 is configured to oscillate by switching between a low-power laser beam for reading and writing to the optical disc 2 and a high-power laser beam for destroying the RE layer 21.
In addition, essential data is written in the RE layer 21 of the optical disc 2 when the optical disc 2 is manufactured, for example.
Other parts corresponding to those of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 7 is a flowchart showing a procedure of content reproduction processing executed by the optical disc apparatus 1 according to Embodiment 3 of the present invention. The content reproduction process is executed when the optical disc 2 is mounted on the disc tray 30. The processes of S11, S13, S14, and S18 to S20 shown in FIG. 7 are the same as the processes of S11, S13, S14, and S18 to S20 shown in FIG. 5 of the first embodiment.

In S11, the CPU 10 that has attempted to read out the essential data from the RE layer 21 determines whether or not the essential data has been read out (S41). The CPU 10 in S41 functions as an essential determination unit in the embodiment of the present invention.
If the essential data cannot be read (NO in S41), that is, if the RE layer 21 is destroyed and cannot be accessed, the CPU 10 moves the process to S13.
If the essential data can be read (YES in S41), the CPU 10 moves the process to S18.

  If YES in S20, the CPU 10 causes the light source 46 to oscillate a high-power laser beam to destroy the RE layer 21 (S42), and moves the process to S14. Each unit of the CPU 10 and the disk drive 3 in S42 functions as invalidating means in the embodiment of the present invention.

  As described above, in the present embodiment, the processing related to the count data such as S15, S16, and S21 shown in FIG. 5 is not executed. This is because the RE layer 21 is destroyed if the content is played once, so it is meaningless to count the number of times the content data is used. Of course, when the upper limit number is N times, the processing related to the number data such as S15, S16, and S21 shown in FIG. 5 is also executed, and when the number of uses indicated by the number data is N times or more, S42 The process is executed.

  The optical disc apparatus 1 as described above can limit the number of times content data is used to the upper limit number or less by destroying essential data recorded in the RE layer 21 under a predetermined condition. Since the essential data cannot be written back, the copyright of the content can be more reliably protected. In addition, while essential data is recorded on the RE layer 21, the content data can be used by different optical disc apparatuses 1, 1,..., So that convenience for the user can be improved.

In Embodiments 1 to 3, the case where essential data is recorded in the RE layer 21 is exemplified, but the present invention is not limited to this. For example, when the optical disc 2 includes a write-once recording layer (so-called R layer) in which data can be written only once in the same recording area, the R data may be recorded on the R layer.
Further, the optical disc device 1 and the optical disc 2 are not limited to the BD player and the BD. The optical disk device 1 may be a BD recorder, a portable DVD player, a television device, a PC, or the like as long as it has a disk drive. The optical disc 2 may be a CD or DVD as long as it is a multi-layer type having a first recording layer and a second recording layer.

  Further, the optical disc apparatus 1 may be configured to select any one of deletion, change, and destruction of the RE layer 21 according to given conditions. For example, the optical disc apparatus 1 normally invalidates the essential data by changing the essential data. However, if the predetermined information is recorded in the RE layer 21 or the ROM layer 22, the essential data is deleted and a serious illegal operation is performed. Is detected, the RE layer 21 is destroyed.

The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is not intended to include the above-described meanings, but is intended to include meanings equivalent to the claims and all modifications within the scope of the claims.
As long as the effects of the present invention are obtained, the optical disk device 1 or the optical disk 2 may include components that are not disclosed in the first to third embodiments.

1 Optical disk device 10 CPU (reproducing means, reading means, essential judging means, condition judging means, invalidating means)
13 Reproduction part (reproduction means)
2 Optical disc 21 RE layer (first recording layer)
22 ROM layer (second recording layer)
3 Disk drive (reading means, invalidating means)
5 PC (data recording device)
6 Content playback system

Claims (9)

A first recording layer on which data is recorded;
In an optical disc formed by laminating a read-only second recording layer in which content data indicating content is recorded in advance,
An optical disc, wherein essential data essential for use of content data recorded on the second recording layer is recorded on the first recording layer.   2. The optical disc according to claim 1, wherein the essential data indicates a file system for managing the content data. The content data is encrypted,
The optical disc according to claim 1, wherein the essential data indicates a decryption key for decrypting the content data.   The optical disk according to claim 1, wherein the essential data indicates permission / denial information indicating permission or prohibition of use of the content data. An optical disc in which a first recording layer in which data is recorded and a read-only second recording layer in which content data indicating content is recorded in advance is stacked, is mounted,
In an optical disc apparatus comprising reproducing means for reproducing content based on content data recorded on a second recording layer of an optical disc mounted thereon,
Reading means for reading data recorded in the first recording layer;
Essential determination means for determining whether the data read by the reading means is essential data essential for use of the content data;
Condition determining means for determining whether or not a predetermined condition meaning prohibition of use of the content data is satisfied;
Invalidating means for invalidating essential data recorded in the first recording layer when it is determined that the condition determining means is established and the essential determining means determines that the essential data is essential data; With
The optical disc apparatus characterized in that the reproduction means reproduces the content when the essential determination means determines that the data is essential.   The invalidation means deletes the essential data recorded in the first recording layer, changes the essential data to data different from the essential data in a predetermined changing procedure, or the first recording 6. The optical disc apparatus according to claim 5, wherein the essential data is invalidated by destroying a layer. An optical disc formed by laminating a first recording layer in which data is recorded and a read-only second recording layer in which content data indicating content is recorded in advance;
In a content reproduction system comprising: an optical disk device having the optical disk mounted thereon, and an optical disk device having reproduction means for reproducing content based on content data recorded on a second recording layer of the loaded optical disk;
The optical disc apparatus is
Reading means for reading data recorded on the first recording layer of the optical disc;
Essential determination means for determining whether the data read by the reading means is essential data essential for use of the content data;
Condition determining means for determining whether or not a predetermined condition meaning prohibition of use of the content data is satisfied;
Invalidating means for invalidating essential data recorded in the first recording layer when it is determined that the condition determining means is established and the essential determining means determines that the essential data is essential data; Have
The content reproduction system, wherein the reproduction means reproduces the content when the essential determination means determines that it is essential data.   8. The content reproduction system according to claim 7, further comprising a data recording device on which the optical disc is mounted and the essential data is recorded on a first recording layer of the mounted optical disc. Content comprising: a first recording layer on which data is recorded; a read-only second recording layer in which content data indicating content is recorded in advance; and an optical disc apparatus on which the optical disc is mounted In the playback system,
In a content reproduction method for reproducing content based on content data recorded on a second recording layer of an optical disc mounted on the optical disc apparatus,
Read data recorded on the first recording layer of the optical disc,
When the read data is essential data essential for use of the content data, the content is reproduced,
The essential data recorded in the first recording layer is invalidated when essential data is recorded in the first recording layer and use of the content data is prohibited. Content playback method.

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