JP2005251243A - Optical information recording method and apparatus and optical information reproducing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent illegal copy by embedding special data separately from usual data in a disk and to realize this with a simple construction. <P>SOLUTION: An optical information recording apparatus is provided with a modulation signal generator 2 generating data recorded in the optical disk, an optical recording circuit 3 generating writing data from the data outputted from the modulation signal generator 2 and an optical beam irradiation means 4 irradiating an original plate 1 of the optical disk with a light beam based on the writing data outputted from the optical recording circuit 3 to form a pit. The optical recording circuit 3 changes the power of the optical beam with which the original plate 1 of the optical disk is irradiated based on the special data and changes the width of the pit to embed the special data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical information recording method and apparatus in which special data is embedded when a master disk of an optical disk is irradiated with a light beam to form pits and data is written, and the optical information recording method and apparatus The present invention relates to an optical information reproducing method and apparatus for reading out special data embedded in the.

In recent years, optical disc media, particularly pre-recorded media, require copy protection technology for preventing unauthorized copying.
At this time, it is necessary to cope with the reproduction of the data recorded on the optical disk by copying the data as it is, and reproducing the data by so-called bit-by-bit replication. In other words, illegal copying is impossible by embedding special data in a method different from normal data writing on the optical disc.

Conventionally, as a method for embedding special data in an optical disc as described above, for example, there is a method described in Patent Document 1 below.
That is, in the recording method described in the cited document 1, when data is written by irradiating a master disk of an optical disk to form pits, special data is embedded by changing the pit width locally. I have to.
JP-A-11-296864

  However, such a recording method requires complicated signal processing in order to write data by locally changing the pit width, and also requires complex signal processing in a reproduction system for reading data. Therefore, there has been a problem that the scale of the processing circuit becomes large and the circuit configuration becomes complicated.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a suitable technique for embedding special data in an optical disc with a simple circuit configuration and used for copy protection of optical disc media.

In order to achieve the above object, the present invention
An optical information recording method for embedding special data when an optical disk master is irradiated with a light beam, pits are formed and data is written,
The special data is embedded as information in the linear velocity direction of the disc by changing the power of the light beam irradiated to the master disc of the optical disc and changing the width of the pit based on the special data. .

The present invention also provides
The special data is embedded as information in the radial direction of the disc by changing the power of the light beam irradiated to the master disc of the optical disc and changing the width of the pit based on the special data. And

And when reading the special data embedded in the optical disc by the above optical information recording method, in the present invention,
When reading data by optically reading the pits formed on the optical disc, special data is extracted by detecting the bottom level or binarized slice level of the RF signal due to the change in the pit width. It is characterized by that.

  Optical disc media, particularly prerecorded media, require copy protection technology for preventing unauthorized copying, and the present invention can be suitably employed as one of them.

  That is, when data written on an optical disk by the method of the present invention is duplicated by so-called bit-by-bit, normal data is duplicated, but special data is embedded as a pit width and cannot be duplicated and lost. It will be. Therefore, it is possible to embed a copy protection key, an ID indicating a ROM disk, or the like as special data that cannot be read normally. Further, it can be combined with other technologies, and more complex and advanced copy protection is possible.

  The method of the present invention does not require complicated signal processing in both the recording system and the reproduction system, so that the above functions can be incorporated with a simple circuit configuration that requires only slight changes to the existing recording apparatus and reproduction apparatus. Can be implemented easily.

Embodiments of the present invention will be described below with reference to the drawings.
The system configuration according to the present invention is divided into a recording system (generation system) and a playback system. FIG. 1 shows the configuration of the recording system and FIG. 2 shows the configuration of the playback system.

First, the recording system of FIG. 1 will be described. This recording system is usually called a mastering apparatus, that is, an apparatus for writing data on a master disk 1 of an optical disk by a laser beam to generate a master.
In this mastering device, data to be written on the optical disk is modulated by the modulation signal generator 2, and data output therefrom is written to the optical disk master 1 from the optical head 4 which is a light beam irradiation means via the optical recording circuit 3. It is. Here, the optical head 4 irradiates the recording surface of the optical disc master 1 with a laser beam to form pits, and writes data.

  During this data writing, the optical disc master 1 is rotationally driven by the spindle motor 7, and the optical head 4 is moved in the radial direction of the optical disc master 1 by the head feed mechanism 5. At this time, the system controller 9 controls the head feed mechanism 5 via the head feed control circuit 6 and also controls the rotation of the spindle motor 7 via the rotation control circuit 8, for example, a CD-DA (Compact Disc- In the case of a constant linear velocity type disc such as Digital Audio (compact disc for music), data is written to the master disc 1 while keeping track pitch and linear density constant.

Data writing by this mastering device will be described in more detail.
Here, the modulation signal generator 2 generates and outputs an EFM (Eight to Fourteen Modulation) signal for CD-DA, for example, in the case of manufacturing a CD-DA disc. The modulation signal generator 2 holds key data which is special data embedded separately from the EFM signal. The key data here is, for example, a key for encryption or used as a disk ID for informing that it is pre-mastered.

  The EFM signal output from the modulation signal generator 2 is input to the optical recording circuit 3, and at the same time, the key data is input to the optical recording circuit 3. The modulation signal generator 2 and the system controller 9 perform communication such as position information and linear velocity information. The system controller 9 controls the rotation control circuit 8 to keep the linear velocity of the optical disk master 1 constant, and at the same time, the EFM data output from the modulation signal generator 2 passes through the optical recording circuit 3 to the optical head. 4 is written on the optical disc master 1.

  The optical recording circuit 3 generates and outputs write data to the optical disc master from the EFM data and key data output from the modulation signal generator 2. At this time, for example, when the key data is 1 (High), the writing laser power is increased, and when the key data is 0 (Low), the laser power is decreased. Thereby, the width of the pit of data written on the optical disc master can be changed.

FIG. 3 shows an example of a recording pattern when key data is embedded in the linear velocity direction of the disc.
That is, here, (A) is key data, (B) is an EFM signal, (C) is laser power, (D) is a pit pattern, and writing is performed based on the key data as shown in (A). A pit pattern such as D) is formed. In this case, when the key data is 1 (High), the laser power increases so that the pit width increases. When the key data is 0 (Low), the laser power decreases so that the pit width decreases. Change. As a result, the key data can be modulated into pit width information and embedded in the linear velocity direction of the disc.

Further, a case where key data is embedded in the radial direction of the disk will be described.
In the recording system shown in FIG. 1, a rotation pulse is output from a rotation control circuit 8 that controls the rotation of the master disk, and is input to the optical recording circuit 3. The optical recording circuit 3 counts and counts the rotation pulses to measure one cycle, that is, one track pitch period, and synchronizes with the measured track period to modulate the pit width by the key data as described above. Do. In this case, the pit width is modulated in units of several tracks for one bit of key data. Thereby, 1-bit key data can be embedded in several tracks in the radial direction of the disk.

  FIG. 5 shows a pit pattern when the key data is embedded in the radial direction of the disk, that is, the width of the pit P of the data written on the disk master 1 in this way is large and small in track units based on the key data. By changing to, key data is embedded in the radial direction of the disk.

Next, the reproduction system of FIG. 2 will be described. This reproduction system is generally called a disc player (or disc drive), that is, a device that reads and reproduces data recorded on the optical disc 11.
The optical disk 11 reproduced here is a reproduction-only optical disk (so-called compact disk) produced by press production using the master disk 1 on which data is written in the recording system shown in FIG. 1 as a master.

  In this disc player, the pits of data written on the optical disc 11 are read by the optical head 12 as reading means, and the data is read out by the optical reproduction circuit 13 from the pits read here.

  At the time of this data reading, the optical disk 11 is rotationally driven by the spindle motor 14, and accordingly, the optical head 12 is moved in the radial direction of the optical disk 11 by the head feed mechanism 15. At this time, a servo signal is sent from the optical reproduction circuit 13 to the system controller 17 via the servo signal processing circuit 16, and based on this, the system controller 17 controls the head feed mechanism 15 via the head feed control circuit 18. At the same time, tracking control of the optical head 12 is performed via the tracking control circuit 19, and further, the rotation of the spindle motor 14 is controlled via the rotation control circuit 20 to read data while keeping the linear velocity of the optical disk 11 constant. Do.

  Here, in the optical reproduction circuit 13, data is read from the pits read by the optical head 12, and the EFM signal is processed in the reproduction data processing circuit 21 from among the data, and normal data reproduction is performed.

  At the same time, an RF signal is sent to the key data processing circuit 22 via the optical reproduction circuit 13. The signal includes the key data component written by the above-described method. At this time, the bottom level of the RF signal is lowered when the width of the pit is large. The key data processing circuit 22 detects the bottom level of the RF signal, or extracts the key data by detecting the slice level of the binary (digital) comparator output, that is, the average level.

FIG. 4 shows an example of a reproduction pattern of key data.
That is, here, (A) is the pit pattern, (B) is the RF signal, (C) is the EFM signal, (D) is the key data, and from the pit pattern as shown in (A) to the key data as (D). Is extracted. In this case, the key data becomes 0 (Low) in the portion where the pit width is small, and the bottom level of the RF signal decreases as the pit width increases, and the key data becomes 1 (High) due to the change. Is extracted.

The system configuration according to the present invention as described above can be suitably used for a copy protection technique for preventing unauthorized copying, particularly in pre-recorded media.
That is, when data written on an optical disk by the method of the present invention is duplicated by so-called bit-by-bit, normal data is duplicated, but key data is embedded as a pit width and cannot be duplicated and lost. become. Therefore, it is possible to embed a copy protection key, an ID indicating a ROM disk, or the like as special data that cannot be read normally.

  In particular, the present invention is characterized in that replication processing is difficult when key data is embedded in the radial direction of the disk. That is, suppose that data is read using a disc player that can read data including pit width information, and this data is directly copied using a cutting machine. When the rotational speeds on the machine side do not completely match, an error occurs in each rotation of the information in the disk radial direction, and finally, it does not make sense as data. In a normal disk player (disk drive), PLL and rotation synchronization synchronized with the internal master clock can be applied, so it is almost impossible to completely synchronize with the rotation control clock in the cutting machine. It is almost impossible for the rotational speed to match the machine. Accordingly, the duplication process when the key data is embedded in the disk radial direction as in the present invention is almost impossible.

  Since the present invention does not require complicated signal processing in both the recording system and the reproducing system as described above, the above functions are incorporated with a simple circuit configuration that requires only slight changes to the existing recording apparatus and reproducing apparatus. Can be implemented easily.

1 is a schematic configuration diagram of an optical information recording apparatus according to the present invention. 1 is a schematic configuration diagram of an optical information reproducing apparatus according to the present invention. It is explanatory drawing of the recording pattern by this invention. It is explanatory drawing of the reproduction | regeneration pattern by this invention. It is explanatory drawing (enlarged view of a pit) of the recording pattern of the disc radial direction by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Optical disk original disk 2 ... Modulation signal generator 3 ... Optical recording circuit 4 ... Optical head (light beam irradiation means)
11: Optical disk 12: Optical head (reading means)
13: Optical reproduction circuit 22: Key data processing circuit (special data processing circuit)

Claims (6)

An optical information recording method for embedding special data when an optical disk master is irradiated with a light beam, pits are formed and data is written,
The special data is embedded as information in the direction of the linear velocity of the disc by changing the power of the light beam applied to the master disc of the optical disc and changing the width of the pits based on the special data. Optical information recording method. An optical information recording method for embedding special data when an optical disk master is irradiated with a light beam, pits are formed and data is written,
The special data is embedded as information in the radial direction of the disc by changing the power of the light beam irradiated to the master disc of the optical disc and changing the width of the pit based on the special data. An optical information recording method. An optical information reproducing method for reading out special data embedded in an optical disc by the optical information recording method according to claim 1 or 2,
When reading data by optically reading the pits formed on the optical disc, special data is extracted by detecting the bottom level or binarized slice level of the RF signal due to the change in the pit width. An optical information reproducing method characterized by the above. An optical information recording device for embedding special data when irradiating a master disk of an optical disc with a light beam, forming pits and writing data,
A modulation signal generator for generating data to be recorded on an optical disc;
An optical recording circuit for generating write data from data output from the modulation signal generator;
A light beam irradiating means for irradiating a master disk of an optical disk based on write data output from the optical recording circuit to form a pit;
With
The optical recording circuit embeds special data as information in the linear velocity direction of the disc by changing the power of the light beam applied to the master disc of the optical disc and changing the width of the pit based on the special data. An optical information recording apparatus characterized by that. An optical information recording device for embedding special data when irradiating a master disk of an optical disc with a light beam, forming pits and writing data,
A modulation signal generator for generating data to be recorded on an optical disc;
An optical recording circuit for generating write data from data output from the modulation signal generator;
A light beam irradiating means for irradiating a master disk of an optical disk based on write data output from the optical recording circuit to form a pit;
With
The optical recording circuit embeds special data as information in the radial direction of the disc by changing the power of the light beam applied to the master disc of the optical disc in units of tracks and changing the pit width based on the special data. An optical information recording apparatus characterized by the above. An optical information reproducing apparatus for reading special data embedded in an optical disc by the optical information recording apparatus according to claim 4 or 5,
Reading means for optically reading the pits formed on the optical disc;
An optical reproduction circuit for reading data from the pits read by the reading means;
A special data processing circuit for extracting special data from the data read by the optical regeneration circuit;
With
An optical information reproducing apparatus, wherein the special data processing circuit extracts special data by detecting a bottom level or a binarized slice level of an RF signal due to a change in pit width.

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