JP2002124034A - Data format conversion method and its apparatus, data recording method and its apparatus, data reproducing method and its apparatus, and optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record additional data as the displacement of recording position of a pit or the change of shape of the pit formed on the basis of main data, and thereby prevent trouble in the reproduction of the main data. SOLUTION: The M (integer which is two or more) bits of additional data are converted into N (integer which is >M) bits. The conversion is performed so that the number of '1' and '0' turns into the same number or the high-level and low-level numbers turn into the same number in terms of NRZI(Non Return to Zero Inverted) notation in the converted N bits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium in which second data as additional data is recorded in addition to first data as main data, and additional data is recorded together with the main data on this optical recording medium. The present invention relates to a data recording apparatus and a data recording method, and a data reproducing apparatus and a data reproducing method for reproducing first and second data from an optical recording medium on which first and second data are recorded.

[0002]

2. Description of the Related Art As optical disks, compact disks (hereinafter abbreviated as CDs) have become widespread. In a CD, after audio data is sequentially divided into blocks and an error correction code or the like is added, an EFM (Eight To Fou) is added.
RNTE (North Return to Zero) modulation.
oInverted) recording.

As a result of the EFM modulation, when a basic cycle which is a cycle of the channel clock is T, pits and lands are repeated by nine kinds of lengths of 3T to 11T in units of the basic cycle T. , Audio data is recorded.

In the case of a CD, pits formed on an optical disk based on recorded audio data have a period of 3T.
A pit length which is a length along a track (hereinafter referred to as a track direction) corresponding to the period 11T is about 0.87.
The pit width, which is the length in the direction orthogonal to the track direction (the track width direction), is about 0.5 μm to 3.18 μm
m, the depth of which is about 0.1 μm.

[0005]

By the way, there is a demand for copyright protection of digital contents such as music recorded on a CD, and it has been proposed to encrypt and record audio data in a next-generation CD. I have. Then, in that case, it has been proposed to record data of an encryption key for decryption at the time of reproduction as additional data together with a CD.

In this case, it is important that the data of the encryption key cannot be reproduced when the content data of the CD is dead-copied. for that reason,
It has been considered to record the encryption key in such a manner that it can be recorded by the mastering technique but cannot be recorded by a recording device for a consumer.

That is, one of them is a wobble method in which a pit recording position is shifted from a center position in a track width direction in accordance with information of an encryption key. FIG. 11 is a diagram for explaining the wobble method.

[0008] In FIG. 11, FIG.
3 shows a serial data string of a part of FM modulation data. This serial data string is subjected to NRZI modulation to generate channel data (FIG. 11B).

In the case of a normal compact disc, as shown in FIG. 11C, irradiation of a linearly moving laser beam is controlled on and off in accordance with the channel data of FIG. A bit string having a pit width of 0.5 [μm] is formed. Therefore, at this time, the center (hereinafter, referred to as a track center) Tc in the width direction of the track including the plurality of pits and the land between the pits is represented by FIG.
As shown by the dotted line in (C), it always coincides with the center Pc of each pit P in the width direction.

On the other hand, in the wobble method, FIG.
As shown in FIG. 1 (D), the pits P are formed by shifting the formation positions of the pits P in the direction orthogonal to the track direction, that is, in the track width direction, according to the additional data. In the example of FIG. 11D, when the additional data is “1”, the formation position of the pit P is shifted in the direction orthogonal to the track direction and to the left of the track center, and the additional data is “0”. In the case of, the formation position of the pit P is shifted in the direction orthogonal to the track direction and to the right of the track center.

At this time, the shift amount of the formation position of the pit P is determined by the center position Pc in the width direction of the pit (FIG. 11D).
The distance between the track center Tc and the track center Tc is, for example, 50 nm, which is a value within the range permitted by the CD standard as the shift amount of the pit formation position when recording the audio data.

The displacement in the track width direction at the position where the pit P is formed is detected as, for example, a tracking error as a light receiving output by a so-called push-pull method, and the tracking error is binarized.
The additional data can be reproduced. However, writable CD-R (Compact Disc-Recorder)
table) or CD-RW (Compact Disc)
-ReWritable), FIG.
Since pits can be formed only as in (C), that is, pits cannot be wobbled, if an illegal copy is made, the information of the encryption key for decrypting the encryption cannot be reproduced, and the proper Copyright protection will be possible.

Another method of recording an encryption key in a form that can be recorded by the mastering technique but cannot be recorded by a consumer recording device is a method of deforming the shape of a pit according to additional data.

FIG. 12 is a diagram for explaining an example of this method. FIG. 12 corresponds to FIG.
FIG. 12D shows a modification of the pit shape. That is, in this example, when the additional data is “1”, the shape of the pit P is a concave shape at the left center portion in the track direction, and when the additional data is “0”, the shape of the pit P is the shape of the track. The central part on the right side of the direction is concave. In this method, the pit P
Is within the range of the standard for reproducing audio data.

Such a deformation of the shape of the pit P is detected as a tracking error as a light receiving output by, for example, a so-called push-pull method, as in the first method described above, and the tracking error is binarized. Thus, the additional data can be reproduced. But,
When recording on a writable CD-R or CD-RW, as described above, FIG. 11C and FIG.
Therefore, if an illegal copy is made, the information of the encryption key for decrypting the encryption cannot be reproduced, and proper copyright protection can be performed.

However, as described above, the additional data recorded by the method of wobbling the pits or the method of deforming the pit shape is extracted from the CD as a tracking error, binarized, and reproduced. For this reason, if the number of “0” or “1” is biased toward one of the additional data, there is a problem that a tracking error occurs during reproduction of audio data due to accumulation of tracking errors.

The present invention relates to a data conversion method suitable for recording and reproducing the above-described additional data, a data recording method using the data conversion method, and a method for reproducing data recorded by the data recording method. It is an object of the present invention to provide a device capable of avoiding the above problems.

[0018]

In order to solve the above-mentioned problems, in a data conversion method according to the present invention, M (M
Is for converting 2 or more integer bits into N (integer where N> M) bits. In the converted N bits, the number of “1” and “0” is the same, Alternatively, NRZI (Non Return to Zero I)
The conversion is performed so that the number of the high level and the number of the low level are the same in the notated).

Further, the data conversion device according to the present invention comprises:
Receiving M (M is an integer of 2 or more) bits of data, "1"
Such that the number of “0” and “0” are the same, or the number of the high level and the low level are the same in the NRZI notation,
It outputs N (N> M integer) bits of data.

If the data conversion method and the data conversion apparatus having the above-described configurations are used, the number of "1" and "0" of the converted binary data becomes the same, or the number of high level and low level in NRZI notation. Are the same, so that tracking errors do not accumulate even if pit wobbling or pit deformation is performed in accordance with the converted data.

According to a seventh aspect of the present invention, in the data recording method, the plurality of pits are formed on an optical recording medium having a track composed of a plurality of pits and lands between the pits based on the first data. Recording the first data and displacing at least a part of the plurality of pits from the center in the width direction of the track based on the second data; In the recording method, the second data is for converting M (M is an integer of 2 or more) bits into N (N> M is an integer) bits, wherein the N-bit data is “1”. So that the number of “0” is the same, or NR
It is characterized by conversion and recording so that the number of high level and low level is the same in ZI notation.

In the data recording method of the present invention, at least a part of the plurality of pits formed based on the first data is moved from the center in the track width direction based on the second data. The second data is additionally recorded by the pit wobble to be displaced. At this time, the second data is converted from M bits to N bits and recorded, and the number of “1” and “0” of the converted binary data is the same, or , NRZI
Since the numbers of the high level and the low level are set to be the same in the notation, even if the pit wobble is performed according to the converted data, the accumulation of the tracking error is reduced. Therefore, it is possible to hardly hinder reproduction of the first data.

[0023] The invention of claim 8 is based on claim 7 described above.
In the data recording method, the pits displaced from the center of the track in the width direction based on the second data are only pits having a predetermined length in the track extension direction.

According to the eighth aspect of the present invention, the pits to be wobbled are only pits having the same length in the track direction. There is no accumulation. Therefore, there is no hindrance to the reproduction of the first data.

According to a fourteenth aspect of the present invention, in the data recording method, the plurality of pits are formed on an optical recording medium having a track composed of a plurality of pits and lands between the pits based on the first data. And a data recording method for recording the first data and deforming and recording the plurality of pits based on second data.
The second data is for converting M (M is an integer of 2 or more) bits into N (N> M integers) bits, and the N-bit data is “1” and “0”. The conversion and recording are performed so that the numbers are the same, or the numbers of the high level and the low level are the same in NRZI notation.

According to the data recording method of the present invention, at least a part of the plurality of pits formed on the basis of the first data is deformed on the basis of the second data. Data is additionally recorded. At this time, the second data is converted from M bits to N bits and recorded, and the number of “1” and “0” of the converted binary data is the same, or , NRZI notation, the number of high levels and the number of low levels are set to be the same, so that even if pit deformation is performed in accordance with converted data, accumulation of tracking errors is reduced. Therefore, it is possible to hardly hinder reproduction of the first data.

According to a fifteenth aspect of the present invention, in the data recording method of the fourteenth aspect, the pit to be deformed based on the second data is a pit having a predetermined length in a track extension direction. It is characterized by being only.

According to the fifteenth aspect of the present invention, the pits to be wobbled are only pits having the same length in the track direction. There is no accumulation. Therefore, there is no hindrance to the reproduction of the first data.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

[First Embodiment of Data Recording Method and Data Recording Apparatus] The first embodiment described below is a case where the present invention is applied to an optical disk such as a CD. FIG. 1 is a diagram showing an optical disc recording device 1 as an embodiment of a data recording device.

The optical disk recording apparatus 1 is used for manufacturing an optical disk as an embodiment of the optical recording medium according to the present invention. In manufacturing the optical disk, first, the optical disk recording device 1 develops the exposed disk master 2 and then performs an electroforming process to create a mother disk. Then, a stamper is formed from the mother disk, a disk substrate is molded using a mold device equipped with the stamper, and a reflection film is applied to the molded disk substrate to manufacture an optical disk.

The master disc 2 to be exposed by the optical disc recording apparatus 1 is formed, for example, by applying a photosensitive agent (photoresist) to a flat glass substrate. The master disc 2 is mounted on a mounting table (not shown) driven to rotate by a spindle motor 3. Spindle motor 3
Drives the disk master 2 under the control of the spindle servo circuit 4.

The spindle motor 3 includes a frequency signal generator (not shown) for generating a frequency signal FG having a frequency corresponding to the rotation speed. The spindle servo circuit 4
The spindle motor 3 is driven so that the frequency signal FG has a predetermined frequency, thereby driving the master disc 2 at a constant linear velocity (CLV).

The recording laser 5 is constituted by a gas laser or the like, and emits a predetermined amount of laser beam. The optical modulator 6 is configured by an electroacoustic optical element or the like, and transmits a laser beam incident from the recording laser 5 to a driving circuit 9 described later.
ON / OFF according to the drive signal S1 supplied from the controller.
The laser beam L from the light modulator 6 enters the mirror 7.

The mirror 7 bends the optical path of the laser beam L by 90 °, for example, and causes the laser beam L to be incident on the master disc 2. The objective lens 8 focuses the reflected light from the mirror 7 on the recording surface of the master disc 2, that is, on the applied photosensitive agent. Although not shown, the mirror 7 is configured so that the reflection angle of the laser beam L can be controlled by a drive signal S2 from a drive circuit 10 described later. By controlling the reflection angle of the mirror 7 by the drive signal S2, the incident position of the laser beam L on the disk master 2 is displaced in the radial direction of the disk master 2, that is, in the direction perpendicular to the track direction (track width direction). Is controlled.

That is, the positions of the pits formed on the disk master 2 are different from the track centers with respect to the track center.
Can be wobbled so as to be displaced to one of the left and right sides in the radial direction. The amount of displacement of the pit formation position is within a predetermined amount that allows reading of the displaced pit without causing the reproduction laser beam to go off-track during reproduction. In other words, the displacement amount is within the pit formation position displacement allowed in the CD standard. For example, this displacement is set to 50 nm.

The mirror 7 and the objective lens 8 are sequentially moved in the radial direction of the disk master 2 by a thread mechanism (not shown) in synchronization with the rotation of the disk master 2. As a result, the optical disc recording apparatus 1 sequentially displaces the condensing position of the laser beam L from the inner peripheral side to the outer peripheral side of the disc master 2, and forms a spiral or concentric track on the disc master 2.

On this track, a pit train corresponding to the modulation signal S1 from the drive circuit 9, wherein the displacement of the pit formation position from the track center is modulated by the modulation signal S2 from the drive circuit 10. Is formed.

In addition to the mirror 7, an optical deflector can be used to displace the pits to the left and right with respect to the recording direction. For example, AOD (Acousto Optical)
Deflector), EOD (Electro Op)
tic Deflector), the recording laser beam can be deflected.

With the optical disk recording apparatus having the above-described recording mechanism, audio data and TOC (Tabl) are recorded.
e of Contents) data is recorded as main data. At this time, in this case, the audio data is encrypted and recorded. In this embodiment, the modulation signal S1 from the drive circuit 9 is
Generated based on the data and the encrypted audio data.

In this embodiment, the data of the encryption key for decrypting the audio data is
Record as additional data. The modulation signal S2 from the drive circuit 10 is generated based on the additional data. Further, in this example, as will be described later, the pits wobbled by the modulation signal S2 based on the additional data are only pits having a length of 11T in the frame sync portion of the EFM frame of the main data, and
Only the frame sync portion of the main data recorded in the lead-in area is set. That is, in this embodiment, the additional data is recorded as the wobble displacement of the 11T pit in the frame sync portion of the main data in the lead-in area.

The recording signal processing for the main data and the additional data will be described below.

[Recording of Main Data] An audio signal SA supplied from a predetermined music source is an analog signal.
It is supplied to a digital conversion circuit (A / D conversion circuit) 11. The A / D conversion circuit 11 converts the audio signal SA into a digital signal and outputs a sampling frequency of 44.1 [kHz].
z], and outputs 16-bit parallel digital audio data DA to the encryption circuit 12.

The encryption circuit 12 includes an encryption key generation circuit 21
Performs encryption processing based on the data of the encryption key from the ECC (Err).
orCorrection Code) Encoder 13
To supply. In this example, the encryption key generation circuit 21
Generate 28-bit encryption key data. The ECC encoder 13 has a TOC (Table of Record) recorded in the lead-in area in the same manner as an existing compact disc.
(entents) data is also input.

The ECC encoder 13 converts the input data into, for example, a CIRC (Cross Interl).
An error correction code is generated and added according to an eave Reed-Solomon Code.

In accordance with an instruction from a system controller (not shown), the ECC encoder 13 performs ECC encoding of the TOC data and outputs the same to the recording modulation circuit 14 when recording in the lead-in area of the master disc 2.
When recording data in the data area of the master disc 2, the audio data DA is ECC-encoded and output to the recording modulation circuit 14.

When the TOC data is recorded in the lead-in area, the pit length of the frame sync portion is 1
The additional data is recorded as the displacement of the recording position of the 1T pit in the left-right direction from the track center.

The TOC data includes, for example, identification data indicating that the disc is an original compact disc created by a stamper, information on music information to be recorded, data on its recording position, and the like.

The recording modulation circuit 14 performs EFM modulation on the data from the ECC encoder 13. In this EFM modulation, 14 channel bits are generated from each byte of data at a cycle that is 14 times the basic cycle T.
As shown in FIG. 1 (A), these 14 channel bits of data are connected by connection bits of 3 channel bits.

The recording modulation circuit 14 converts the data generated as described above into, for example, a serial data string as shown in FIG. 11 (A) and NRZI-modulates it, for example, as shown in FIG. 11 (B). Channel data D1 as shown in FIG.
Is generated and supplied to the drive circuit 9.

The drive circuit 9 outputs the channel data D1
Then, a drive signal S1 for turning on / off the laser beam corresponding to the logical level of the channel data D1 is generated. In this embodiment, for example, as shown in FIG. 11C, the channel data D1 except for the frame sync portion of the EFM frame of the data in the lead-in area is the same as in the case of a normal compact disc.
The laser beam L from the recording laser 5 is on / off controlled by the drive signal S1 corresponding to the pit width 0.
A pit row of 5 [μm] is formed.

[Regarding Recording of Encryption Key Data to be Recorded as Additional Data] EF of Lead-in Area Data
In the frame sync portion of the M frame, the formation position of the pit having a length of 11T is shifted left and right in a direction orthogonal to the track direction in accordance with the encryption key data as additional data. That is, the logical “0” or logical “1” of each bit of the data of the encryption key as the additional data is expressed by E
The pit length of the frame sync part of the FM frame is 1
The recording is performed by assigning the right and left displacements in the direction orthogonal to the track direction of the recording position of the 1T pit.

At this time, as described in the above-mentioned subject, the displacement of the pit recording position in the direction orthogonal to the track direction becomes a component of the tracking error, which accumulates and affects the reproduction of the main data. Must not occur.

Therefore, in this embodiment, the additional data is handled with 6 bits as a symbol unit, and the 6 bits / symbol is converted into 8 channel bits / symbol. Then, the converted 8-channel bit data has the same number of logic “0” and logic “1”.

In this way, the pits displaced in the direction perpendicular to the track direction are pits having the same length of 11T and the same number of pits are displaced to the left and right. Even if the pit recording position is displaced in the direction orthogonal to the track direction, the tracking error always becomes 0 in one symbol unit, and the tracking error is not accumulated due to the additional data.

In this embodiment, the additional data is recorded with an error correction code and an error detection code generated and added. That is, the encryption key data from the encryption key generation circuit 21 is supplied to the encryption circuit 12 and also to the ECC encoder 22.

In the ECC encoder 22, first, 1
A 16-bit CRC (Cyclic Redundancy C) for error detection is added to the 28-bit encryption key data.
Heck) code is added to make a total of 144 bits of additional data.

In this embodiment, the 144-bit additional data is recorded over three blocks (= subcode frame) of the main data. Therefore, it is necessary to record 48-bit encryption key data per block. However, in this embodiment, since 6-bit additional data is converted into 8-channel bits, it is necessary to record 64 channel bits in one block.

In a CD, one block corresponds to FIG.
As shown in (A), it consists of 98 EFM frames. Since the additional data is recorded in the frame sync portion of each EFM frame, 98 blocks of additional data can be recorded per block. In this embodiment, additional data per block is shown in FIG.
It is recorded as a data format as shown in FIG. In FIG. 2B, the number in parentheses indicates the number of bits of the original encrypted data, and the number outside the parentheses indicates that the data has been converted to eight channel bits.

That is, in FIG. 2B, two bits recorded in the frame sync part of the first two frames of the block are sync bits (synchronization bits) of additional data per block. Regarding the two sync bits, the recording position of the pit is not shifted left and right. By setting the sync bit to a pit located at the track center, it becomes easy to detect the sync bit for the additional data.

Since the first two frames of the block are portions for detecting a synchronization pattern in the sub-coding format, the affinity between the synchronization processing of the additional data and the synchronization processing of the sub-code data is improved.

After this sync bit, eight data symbols (48 bits) are included. As described above, the data of the encryption key handles 6 bits as a symbol unit. However, FIG. 2B shows channel bits, and additional data is converted from 6 bits to 8 channel bits. Therefore, in FIG. 2B, one symbol is shown as 8 channel bits. . However, in order to facilitate understanding, in FIG. 2B, the number of bits before data conversion, that is, 6 bits, is shown in parentheses. After the eight data symbols, four parity symbols generated based on the eight data symbols are added.

In order to make the data format as shown in FIG. 2B, the ECC encoder 22 adds a 16-bit CRC code to the 128-bit encryption key data from the encryption key generation circuit 21 as described above. Then 1
The 44-bit data is first divided into three for every 48 bits, and the 48-bit data is converted into eight symbol data in 6-bit units. Then, the (12, 8, 5) Reed-Solomon code is generated for the eight symbol data on, for example, GF (2 ⁶ ). Then, the generated parity data of 4 symbols is set to 8
The data is added to the data of the encryption key of the symbol and interleaved.

[0064] In the CD, subcode regard to R channels ~W channel over GF (2 ⁶⁾ (24,
20, 5) Since the processing is performed on a 6-bit basis by performing the ECC processing using the Reed-Solomon code, there is an advantage that the above-described additional data has good affinity with the processing of the subcode.

The additional data of 6 bits / symbol from the ECC encoder 22 is supplied to a 6-8 data conversion circuit 23.
Supplied to The 6-8 data conversion circuit 23 includes a 6-8 conversion table, and converts 6-bit / symbol additional data to 8-channel bits / symbol additional data.

In this case, the 8-channel bit data after the conversion is such that the number of logic "0" and the number of logic "1" are four out of 256 data, and " Sixty-four pieces of data in which “0” or “1” is not continuous are selected. FIG. 3 shows an example of the 6-8 conversion table.

The additional data converted to 8 channel bits / symbol by the 6-8 data conversion circuit 23 is supplied to a recording position detection circuit 24. Recording position detection circuit 24
Is also supplied with the frame sync of the main data from the recording modulation circuit 14.

In the case of a CD, since the main data is so-called edge recording, the relationship between the high level and the low level of the frame sync is different from the case shown in FIG.
(D). Since the pits are recorded, for example, corresponding to the high-level portion, a pit having a length of 11T in the frame sync portion is formed corresponding to the front 11T of the frame sync (FIG. 4B or FIG. 4 (C)) and the case where it is formed corresponding to the rear 11T (FIG. 4 (E) or FIG. 4 (F)).

The recording position detection circuit 24 is provided for the disc master 2
Of the pit having a length of 11T formed on the front side or the rear side of the frame sync. Then, according to the result, the recording position detection circuit 24 indicates the period during which the 11T pit is formed, and according to the logical value of the data from the 6-8 data conversion circuit 23, the 11T pit is A signal is supplied to the drive circuit 10 indicating which of the left and right directions to displace in the direction perpendicular to the track direction.

The drive circuit 10 shifts the recording position of the pit having a length of 11T in the frame sync according to this signal. That is, as shown in FIG. 4A, when the 11T pit is formed in the 11T section on the front side of the frame sync when the additional data is “1”, as shown in FIG. The pit is formed such that the position of the pit center Pc is displaced from the track center Tc by 50 nm in the left direction orthogonal to the track direction.

When the 11T pit is formed in the 11T section in front of the frame sync as shown in FIG. 4A, when the additional data is "0", the data is shown in FIG. 4C. Thus, the pit is formed such that the position of the pit center Pc is displaced from the track center Tc by 50 nm in the right direction orthogonal to the track direction.

When the 11T pit is formed in the 11T section behind the frame sync as shown in FIG. 4D, when the additional data is "1",
As shown in FIG. 4E, the pit is formed such that the position of the pit center Pc is displaced from the track center Tc by 50 nm in the right direction perpendicular to the track direction.

When the 11T pit is formed in the 11T section behind the frame sync as shown in FIG. 4D, when the additional data is "0",
As shown in FIG. 4F, the pit is formed such that the position of the pit center Pc is displaced from the track center Tc by 50 nm in the right direction perpendicular to the track direction.

In this embodiment, although not shown, the drive circuit 10 is controlled by a control signal from the system controller to operate only in the lead-in area. Therefore, only the data recorded in the lead-in area is displaced in the direction perpendicular to the track direction in the recording position of the 11T pit having the frame sync length.

As described above, in this embodiment, audio data is encrypted and recorded, and as additional data, the data of the encryption key for decryption is orthogonal to the pit track direction. Is assigned to the left and right displacements in the direction of movement.

In this embodiment, the additional data is converted by 6-8 into data having the same number of logical "0" s and logical "1s". In this example, the frame sync 11
Since the additional data is recorded by being assigned to the displacement of the pit of T, the tracking error due to the displacement of the recording position of the pit due to the additional data at the time of reproduction becomes 0 in a symbol unit of the additional data and can be accumulated. Absent.

In addition, in this embodiment, since the data of the encryption key of the additional data is recorded only in the lead-in area, it does not participate in the tracking during the reproduction of the audio data at all, and the audio data is faithfully reproduced. It is something that is played.

[Second Embodiment of Data Recording Method and Data Recording Apparatus] In the second embodiment,
The encryption key as additional data is 11
A pit shape having a length of T is allocated and recorded.

That is, in the second embodiment, the 11T pits in the frame sync correspond to the pits shown in FIG.
As shown in FIG. 5B, when the additional data is “1” in the 11T section before the frame sync, the pit is located on the right side in the track direction of the pit as shown in FIG. Is deformed into a concave shape. The pit PR having a concave portion DR at the center portion on the right side has a pit width (the size of the pit in a direction orthogonal to the track direction) at the concave portion DR within the allowable range of the CD standard. Have been.

As shown in FIG. 5A, when an 11T pit is formed in the 11T section in front of the frame sync, when the additional data is "0", the pit is shown in FIG. 5C. As described above, the pit is deformed into a shape in which the central portion on the left side in the track direction of the pit is concave.
The pit PL having the concave portion DL at the left central portion also has a pit width in the concave portion DL within the allowable range of the CD standard.

As shown in FIG. 5D, when the 11T pit is formed in the 11T section behind the frame sync, when the additional data is "1",
As shown in FIG. 5E, the pit is deformed into a shape in which the right central portion of the pit in the track direction is concave. The pit PR having a concave portion DR in the center portion on the right side has a pit width at the concave portion DR within an allowable range of the CD standard.

When the 11T pit is formed in the 11T section behind the frame sync as shown in FIG. 5D, when the additional data is "0",
As shown in FIG. 5F, the pit is deformed into a shape in which the left central portion of the pit in the track direction is concave. The pit PL having the concave portion DL at the left central portion also has a pit width within the allowable range of the CD standard.

FIG. 6 shows an example of a data recording apparatus when the second embodiment is applied to an optical disk such as a CD, as in the first embodiment. Comparing the optical disc recording device 1a of the example of FIG. 6 with the optical disc recording device 1 of the example of FIG. 1, the difference is that a drive circuit 25 is used instead of the drive circuit 10. The optical modulator 6 according to the second embodiment controls on / off of the laser beam L according to the drive signal S1 from the drive circuit 9 and also controls the laser beam L according to the drive signal S3 from the drive circuit 25. To change the light amount of the laser beam L. The change in the light amount of the laser beam L appears as a change in the width of a pit to be formed.

In the case of the second embodiment, the driving circuit 2
The drive signal S3 from 5 controls the reflection angle of the mirror 7 and controls the optical modulator 6 to reduce the light amount of the laser beam L. The drive signal S3 is one of the frame sync parts of the main data in the lead-in area.
In a predetermined period (a portion corresponding to the recessed portion DL or DR) of a substantially central portion of the 1T pit in the track direction,
Depending on whether the logical value of the additional data is “0” or “1”, the incident position of the laser beam on the master disk 2 is set to the left or right in the direction orthogonal to the track direction. The laser beam L at that time.
Is controlled so as to reduce the amount of light.

That is, for example, when the additional data is logic "1", as shown in FIG. 5B and FIG. 5E, the laser in the track direction position corresponding to the recessed portion DR of the 11T pit is provided. The center of the beam (corresponding to the center Pc of the pit) is shifted to the left direction perpendicular to the track direction by, for example, 50 nm, and the laser beam L
Reduce the amount of light. As a result, a pit PR having a recess DR of 100 nm on the right side in the track direction is provided.
Is formed.

For example, when the additional data is logic "0", as shown in FIGS. 5 (C) and 5 (F), at the track direction position corresponding to the recessed portion DL of the 11T pit, The center of the beam (corresponding to the center Pc of the pit) is shifted to the right direction perpendicular to the track direction by, for example, 50 nm, and the light amount of the laser beam L is reduced. Thereby, 100 on the left side in the track direction
A pit PL having a concave portion DL having a depth of nm is formed.

The other structure is the same as that of the first embodiment.

As described above, according to the second embodiment, as shown in FIG. 5, the encryption key as the additional data is obtained by modifying the shape of the pit having a length of 11T in the frame sync. And recorded.

The deformation of the pit shape shown in FIG. 5 is merely an example, and the present invention is applicable to any shape as long as it is extracted as a tracking error signal and reproduced in a binary form. Good.

[Embodiment of Data Reproducing Apparatus and Data Reproducing Method] FIG. 7 shows an optical disc formed based on the master disc produced by the data recording apparatus of the first and second embodiments. The data can be reproduced by an optical disk reproducing device as an embodiment of the data reproducing device. The optical disk reproducing device 30 of the example of FIG.
Can reproduce audio data from both an existing CD and an optical disk (hereinafter, referred to as an ExCD) formed from a master disk recorded by the data recording devices of the first and second embodiments described above. .

An optical disk 31 such as a compact disk or an ExCD is rotationally driven at a constant linear velocity by a spindle motor 32 under speed servo control by a spindle servo circuit 33.

The optical disk 31 is read by the optical pickup 34, and the output signal of the optical pickup 34
The signal is supplied to the circuit 35. The optical pickup 34 irradiates the optical disk 31 with a laser beam from a built-in semiconductor laser, and receives the returned light by a predetermined light receiving element. RF
The circuit 35 amplifies the output signal from the above-described light receiving element of the optical pickup 34 and calculates the signal, and outputs the reproduced signal RF.
And a tracking error signal TE and a focus error signal (not shown). Based on the tracking error signal TE and the focus error signal, the servo circuit 36 generates each servo signal for performing each of the servo of the objective lens of the optical pickup 34 and the servo of the focus servo, and supplies the servo signal to the optical pickup 34. I do.

Optical pickup 34 and RF circuit 35
Is configured as shown in FIG. 8 as an example. In FIG. 8, the quadrant detector 51 has four light receiving elements A, B, C, and D divided in the track direction of the disk and in a direction orthogonal to the track direction. Light receiving elements A, B,
The detection signals SA, SB, SC, and SD of C and D are calculated by a calculation circuit in the RF circuit 35.

The light receiving elements A to D
, Ie, SA + SB + SC
The reproduction signal RF is formed by the operation of + SD. Also,
The addition circuits 53 and 54 and the subtraction circuit 55
{(SA + SB)-(SC + SD)} is calculated,
As a result, a tracking error signal TE is formed.

The signal level of the reproduced signal RF changes in accordance with the pits and lands formed on the optical disk 31.
Further, the tracking error signal TE is transmitted to the frame sync 11T of the lead-in area formed on the optical disc 31.
Changes depending on the displacement direction or shape of the pit.

As a configuration for detecting the tracking error signal TE, various types can be used other than the configuration shown in FIG. For example, a so-called three-beam method using three beam spots, a so-called push-pull method using a two-segment detector, a so-called heterodyne method, etc., in which a difference between light receiving outputs in the diagonal direction of a four-segment detector is sampled at an edge of an RF signal. can do.

The tracking error signal TE is supplied to the servo circuit 35, so that the spot of the read laser beam on the optical disk 31 passes through the track center.

When the optical disk 21 is an ExCD, the level of the tracking error signal TE changes according to the displacement of the recording position of the 11T pit of the frame sync of the data in the lead-in area and the pit shape. However, as described above, the tracking error becomes 0 due to integration between 8 EFM frames for extracting 8 channel bits for one symbol of the additional data.

Therefore, even when the optical disk 31 is an ExCD disk, the recording position is not changed according to the additional data, and the recording position is not affected by the pits whose shape changes.
The spot of the reading laser beam is made to pass through the track center. Further, since the displacement amount and the shape change of the recording position of the pit according to the additional data are suppressed within the allowable range of the CD standard, the displaced or deformed pit can be correctly read.

Further, by setting a predetermined threshold value for the tracking error signal TE and binarizing it, displacement of the pit from the track center,
The additional data recorded according to the deformation of the pit is reproduced.

That is, for example, if the recording position is as shown in FIG.
When the laser beam scans a pit displaced to the left of the track center as shown in FIG. 4E, the tracking error signal TE is large in the positive direction, for example, as shown in FIG. 9A. Level 9
Since it becomes larger than the threshold value θ1 shown in (A), it is reproduced as logic “1”.

Also, the recording position is shown in FIG.
When the laser beam scans a pit displaced to the right of the track center as shown in FIG.
As shown in (B), the tracking error signal TE is
For example, since the level becomes large in the negative direction and becomes lower than the threshold value θ2 shown in FIG. 9B, it is reproduced as logic “0”.

When the laser beam scans a pit PR having a recess DR on the right side in the track direction as shown in FIGS. 5B and 5E,
As shown in (A), the tracking error signal TE is
For example, since the level becomes large in the positive direction and becomes larger than the threshold value θ1 shown in FIG. 9A, it is reproduced as logic “1”.

When the laser beam scans the pit PL having the concave portion DL on the right side in the track direction as shown in FIGS. 5C and 5F,
As shown in (B), the tracking error signal TE is
For example, since the level becomes large in the negative direction and becomes lower than the threshold value θ2 shown in FIG. 9B, it is reproduced as logic “0”.

Returning to FIG. 7, the reproduction signal RF from the RF circuit 35 is supplied to the EFM demodulation circuit 37. The EFM demodulation circuit 37 performs EFM demodulation on the reproduction signal RF output from the RF circuit 35 and supplies the demodulated data to the ECC decoder 38.

The ECC decoder 38 performs error correction processing by CIRC. Then, the data after the error correction processing is supplied to the decryption circuit 39. Decryption circuit 39
Is controlled by a control signal from the system controller 40.
When playing an existing CD, it is bypassed (through) and
In the case of xCD, the encryption is decrypted using the encryption key data reproduced from the disk, as described later.

The decrypted signal from the decryption circuit 39 is
Alternatively, the passed through digital audio data is output through the output terminal 41 and the D / A converter 4
The signal is returned to an analog audio signal by 2 and output through an output terminal 43.

On the other hand, the tracking error signal TE from the RF circuit 35 is supplied to the binary demodulation circuit 45 via the gate circuit 44. The gate signal from the gate signal forming circuit 46 is supplied to the gate circuit 44. The gate signal forming circuit 46 receives the demodulated data from the EFM demodulating circuit 37, forms a gate signal for opening the gate in a frame sync section, and supplies the gate signal to the gate circuit 44. Also,
The system controller 40 supplies a gate signal to the gate circuit 44 to open the gate when the reproduction position is in the lead-in area. Therefore, the gate circuit 44 is in the gate open state only during the frame sync section of the main data from the read area.

The binary demodulation circuit 45 includes the gate circuit 44
Tracking error signal T in the frame sync section from
E is received as an input signal.

Immediately after the optical disk 31 is loaded, the system controller 40
Is moved to a position where the lead-in area of the optical disc 31 is reproduced, and the TOC data recorded in the lead-in area of the optical disc 31 is reproduced. The decoded data of the TOC data is transmitted to the ECC decoder 3
8 to the system controller 40.

In this lead-in area, the gate circuit 44 is opened as described above, so that the binary demodulation circuit 45 outputs the tracking error signal TE in the frame sync section.
In response, a binarization process is performed. Here, in the case of an existing CD, the pits of the frame sync in the lead-in area are not wobbled or deformed.
In the binarization circuit 45, binarized data cannot be obtained. On the other hand, in the case of ExCD, the pits of the frame sync in the lead-in area are wobbled or deformed according to the additional data, so that binary data is obtained. The binarization circuit 45 supplies the system controller 40 as to whether or not the binarized data has been obtained, as an existing CD or ExCD disc discrimination output.

The system controller 40 recognizes whether the loaded optical disk 31 is an existing CD or ExCD from the discrimination output from the binarization circuit 45.
Then, as described above, the system controller 40
When it recognizes that the loaded optical disk 31 is an existing CD, the decryption circuit 39 controls to pass through the data. Also, the system controller 40
Controls the decryption circuit 39 to execute when it recognizes that the loaded optical disk 31 is an ExCD.

When the loaded optical disk 31 is an ExCD, the binarization circuit 45 determines the displacement of the pit recording position and the deformation of the pit shape in each frame sync of the lead-in area as described above. Binary demodulation is performed on the recorded encrypted data as additional data. And
The binary demodulation circuit 45 supplies the binary-demodulated additional data to the error check circuit 47.

Further, the error check circuit 47 performs an error check on the additional data in which one symbol has eight channel bits. As an example of an error check method for the additional data of 8 channel bits in this case, there is a parity check method. That is, in the case of this example, the symbol of the 8 channel bits of the additional data is composed of four “0” s and “1” s. It is. Therefore, it is possible to obtain a checksum for each symbol / 8 channel bit without adding a check bit to the data, and to perform an error check depending on whether or not this is "0".

Also, since the eight-channel bit symbols of the additional data are composed of the same number of “0” and “1” for every four, one symbol corresponds to the additional data of eight channel bits for each symbol. In addition, an error check can be performed based on whether or not the number of “0” is equal to the number of “1”. Also, 1
It depends on whether the number of “0” in the symbol is four (half of the number of bits of eight channel bits) or the number of “1” is four (half of the number of bits of eight channel bits). Error checking can be performed.

As a result of the error check, when it is determined that the number of “0” and the number of “1” are the same and there is no error, the error check circuit 47 sets the error flag EF to indicate no error. As "0", the data is supplied to the data reverse conversion circuit 48 and the symbol data S
S is supplied to the data inverse conversion circuit 48.

As a result of the error check, since the number of “0” is different from the number of “1”, when it is determined that an error has occurred, the error check circuit 47 sets the error flag EF to indicate that there is an error. The error flag EF is supplied to the data reverse conversion circuit 48. However, at this time, the error check circuit 47 does not supply the symbol data to the data inverse conversion circuit 48.

The data inverse conversion circuit 48 has an error flag E
When F is "0", the conversion from the symbol data of 8 channel bits sent from the error check circuit 47 to the original data of 6 bits / symbol is performed as shown in FIG.
Is performed using the conversion table shown in FIG. When the error flag EF is “1”, the data inversion circuit 48
The above-mentioned 8-6 data conversion is not performed, and predetermined 6 bits, which are predetermined, in this example, 6 bits are all “0”.
Output data. Then, the data reverse conversion circuit 48
Supplies 6 bits / symbol data to the ECC decoder 49 together with the error flag received from the error check circuit 47.

The ECC decoder 49 performs an error correction process using the four parity symbols described above. As a result, the information of the encryption key is reproduced. The information of the reproduced encryption key is sent from the ECC decoder 49 to the decryption circuit 39.
Supplied to The decryption circuit 39 performs decryption processing on the audio data based on the information on the encryption key.

The above-described additional data reproduction processing operation is described in FIG.
0 will be described again with reference to the flowchart of FIG.

First, it is determined whether or not the data is to be reproduced from the lead-in area (step S1). If the data is not to be reproduced from the lead-in area, the routine exits from the additional data reproduction processing routine.

When it is determined that the data is to be reproduced from the lead-in area, it is determined whether or not the data is in the frame sync section of the main data (step S2). If it is determined that the section is a frame sync section of the main data, the tracking error signal TE is binarized (step S3). Then, the data of 8 channel bits / symbol is restored (step S4).

Next, an error check is performed on the data of 8 channel bits / symbol (step S5).
As described above, this error check is performed by a parity check using a checksum or by checking whether the number of “0” and “1” of 8 channel bits / symbol is equal.

Then, the result of this error check is O
It is determined whether it is K (that is, there is no error) (step S6). If it is determined that the data is OK, 8-channel bit / symbol data is converted into 6-bit / symbol data using the 6-8 conversion table.
6 conversion is performed (step S7). Next, 6 bits /
An error correction process is performed on the symbol data (step S8), and the reproduced data is output (step S9).

As a result of the error check in step S6, when it is determined that the result is NG, that is, there is an error, an error flag EF is set (set to "1") (step S10), and 6 bits / symbol As data, for example, data in which all 6 bits are “0” is output (step S11). Thereafter, the process proceeds to step S8.

If the encryption key data cannot be reproduced for the ExCD, the data in the lead-in area is read a plurality of times and the encryption key data is read again. Even if the encryption key cannot be reproduced, the fact is displayed on a display (not shown) to notify the user.

As described above, the data that has been encrypted and recorded on the optical disk as a track composed of pits and lands is recorded on the same disk by being allocated to the displacement of the recording position of the pit or the deformation of the pit. The encryption is decrypted based on the data of the encryption key and reproduced.

In this case, the additional data assigned to the displacement of the recording position of the pit or the deformation of the pit can be reproduced by binarizing the tracking error signal, but since it is a tracking error signal, There is a possibility that reproduction of the main data may be hindered. But,
In the above-described embodiment, the pits whose recording positions are displaced or deformed in accordance with the additional data are only pits having a length of 11T of the frame sync.
Since the bit / symbol additional data is converted into 8-channel bit / symbol additional data having the same number of “0” and “1” and recorded, the tracking error becomes 0 in one symbol unit, and It does not hinder the reproduction of the video.

Moreover, since the encryption key data is allocated and recorded only in the pits of the main data in the lead-in area, there is no effect on the reproduction of audio data.

Further, since the additional data is allocated to the displacement or deformation of the recording position of the pit of the specific pattern portion and is recorded at a predetermined cycle called a frame sync in the main data, the additional data can be extracted and extracted. There is an effect that reproduction becomes easy.

In this embodiment, the channel bits of the additional data are converted so that the number of “0” and the number of “1” are the same. Error detection can be performed without adding redundant bits such as bits. That is, the code itself after the data conversion has an error detection capability.

The displacement of the recording position of the pit and the deformation of the pit shape are possible at the time of recording on the master disc. However, in the case of a CD-R or CD-RW, such a displacement or deformation is caused. Cannot be recorded, so the recorded data of ExCD
In the case of -R or CD-RW, since the data of the sound key recorded as the additional data is not reproduced, the encryption of the audio data becomes indecipherable, thereby effectively protecting the copyright from illegal duplication recording. Will be able to do it.

[Other Embodiments and Modifications] In the first and second embodiments of the data recording method and the data recording apparatus described above, the data of the encryption key may be, for example, double, triple, or more. May be recorded repeatedly. In such a case where recording is performed a plurality of times, ECC (four parity symbols) can be made unnecessary. In that case, if the ECC is not required, the data of the encryption key per one time is divided into 144 blocks in two blocks.
Bits can be assigned and recorded.

In the above example, the additional data is recorded as the displacement of the recording position of the pit having a length of 11T in the frame sync or the change in the pit shape. In this case, the additional data may be recorded as a change in the recording position of a pit having the same pit length or a change in the pit shape.
In this case, for example, if the additional data is to be recorded only in the lead-in area, all the data in the lead-in area is reproduced before the reproduction of the audio data, so that the additional data is stored in the pit recording position. The predetermined length pits assigned to the displacements and the pit shape changes are detected and recorded, and the detected recording position displacements and pit shape changes of the predetermined length pits are determined by the logic "0" or "1" of the additional data. By detecting which one corresponds, the additional data can be reproduced.

Further, instead of the frame sync, the additional data can be allocated and recorded as described above in a pit portion of data that repeats at a predetermined period, such as a subcode portion. Also in this case, there is an advantage that the additional data can be easily detected by detecting the displacement of the recording position of the pit or the change of the pit shape at every predetermined period.

Further, additional data may be allocated to the pit portion of data of a specific pattern other than the frame sync and recorded as described above. In this case, since the additional data can be detected by detecting the specific pattern, there is an advantage that the detection of the additional data is easy.

In the above description, the additional data is recorded in the lead-in area only by assigning it to the pit displacement or the like. However, the additional data may be recorded in the lead-out area or the data area. Further, the information may be recorded in the plurality of areas.

The additional data is not limited to the data of the encryption key. For example, copyright information can be recorded, and text information of lyrics can be recorded.

The data recorded as main data is not limited to audio data, but may be, for example, image data, game program data, or the like.

The data conversion is not limited to the 6-8 conversion, but from two or more M (M is an integer) bits,
In all cases of converting to N (an integer greater than N) bits,
The present invention is applicable.

In the above description, the additional data is N
Although the number of channel bits “0” and “1” is considered as a problem, if the N channel bits of the additional data are NRZI modulated and recorded, the number of high level and low level in NRZI notation should be the same. Is to do so.

Further, the optical recording medium is not limited to an optical disk, and the present invention is applicable to any medium that forms pits.

[0143]

As described above, according to the present invention, even when the additional data is assigned to the displacement of the recording position of the pit recorded according to the main data or the change in the pit shape, the recording is performed in the main data. Data reproduction can be prevented from being hindered.

Further, according to the present invention, it is easy to reproduce and extract the additional data, and due to the error detection capability of the additional data itself after data conversion to be recorded, error detection can be performed without requiring redundant bits. There is also an effect.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a data recording device according to the present invention.

FIG. 2 is a diagram for explaining a data format of additional data recorded by the first embodiment of the data recording device.

FIG. 3 is a diagram showing an example of a 6-8 conversion table.

FIG. 4 is a diagram showing an example of a recording mode of additional data recorded by the first embodiment of the data recording device.

FIG. 5 is a diagram illustrating an example of a recording mode of additional data recorded by a second embodiment of the data recording device.

FIG. 6 is a block diagram of a data recording apparatus according to a second embodiment of the present invention.

FIG. 7 is a block diagram of a data reproducing apparatus according to an embodiment of the present invention;

FIG. 8 is a diagram showing a configuration example of a part of FIG. 7;

FIG. 9 is a diagram for describing binarization processing of additional data in the embodiment of the data reproducing apparatus.

FIG. 10 is a flowchart illustrating an operation of reproducing additional data in the embodiment of the data reproducing apparatus.

FIG. 11 is a diagram for explaining an example in which additional data is recorded as a displacement of a recording position of a pit.

FIG. 12 is a diagram for describing an example in which additional data is recorded as a pit deformation.

[Explanation of symbols]

2, 31 ... optical disk, 3, 32 ... spindle motor,
5: Recording laser, 6: Optical modulator, 7: Mirror, 8: Objective lens, 9, 10: Drive circuit, 12: Encryption circuit, 1
3, 22 ECC encoder, 14 recording modulation circuit, 2
1: an encryption key generation circuit, 23: a 6-8 data conversion circuit,
34: Optical pickup, 35: RF circuit, 37: EFM
Demodulation circuit, 38, 49 ECC decoder, 39 Decryption circuit, 44 Gate circuit, 45 Binary demodulation circuit, 46
... Gate signal forming circuit, 47 ... Error check circuit, 4
8. Data reverse conversion circuit (8-6 conversion circuit)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G11B 7/24 563 G11B 7/24 563M 565 565D 20/12 20/12 H03M 7/14 H03M 7/14 BF term ( 5D029 WA05 WA18 WA21 5D044 AB05 BC03 CC06 DE22 DE50 DE52 DE70 EF05 FG18 GK12 GK17 GL01 GL13 GL21 HL08 5D090 AA01 BB01 BB02 CC01 CC04 CC14 DD03 FF09 GG03 GG17 GG33

Claims (45)

[Claims] 1. M (M is an integer of 2 or more) bits, N (N
> M integer) bits, and in the converted N bits, the number of “1” and “0” is the same, or NRZI (Non Return trun).
o Zero Inverted) data conversion method, wherein conversion is performed so that the number of high levels and the number of low levels are the same. 2. The data conversion method according to claim 1, wherein said M is M = 6, and said N is N = 8. 3. The data conversion method according to claim 1, wherein, in the converted N bits, the continuation of “1” and “0” is suppressed. 4. Receiving M (M is an integer of 2 or more) bits of data so that the number of "1" and "0" are the same, or the number of high level and low level is the same in NRZI notation. A data converter that outputs N (N> M integer) bits of data. 5. The data conversion device according to claim 4, wherein said M is M = 6 and said N is N = 8. 6. The data conversion device according to claim 4, wherein, in the converted N bits, the continuation of “1” and “0” is suppressed. 7. A plurality of pits are formed on an optical recording medium having a track formed by a plurality of pits and lands between the pits based on first data, and the first data is recorded. A data recording method for recording the second data by displacing at least a part of the plurality of pits from a center in a width direction of the track based on the second data; M (M is an integer of 2 or more) bits is converted into N (N> M integer) bits, and the number of “1” and “0” is the same in the N-bit data. Or a data recording method characterized by converting and recording so that the number of high levels and the number of low levels are the same in NRZI notation. 8. The data recording method according to claim 7, wherein the pits displaced from the center in the width direction of the track based on the second data have a predetermined length in the track extension direction. A data recording method characterized in that the data recording method is only performed. 9. The data recording method according to claim 7, wherein the pits displaced from the center of the track in the width direction based on the second data repeat at a predetermined cycle of the first data. A data recording method characterized by pits formed by data. 10. The data recording method according to claim 7, wherein the pit displaced from the center in the width direction of the track based on the second data is a track extension of a specific pattern portion of the first data. A data recording method, wherein a length in a direction is only a predetermined pit. 11. The data recording method according to claim 7, wherein the second data is recorded at a predetermined position on the optical recording medium. 12. The data recording method according to claim 11, wherein the optical recording medium is an optical disk, and wherein the second data is recorded in a lead-in area. 13. The data recording method according to claim 7, wherein said first data is recorded after being encrypted, and said second data is an encryption key for decrypting the data. A data recording method characterized by being information. 14. A plurality of pits are formed on an optical recording medium having a track composed of a plurality of pits and lands between the pits based on the first data, and the first data is recorded. In addition, in the data recording method for recording by deforming at least a part of the plurality of pits based on the second data, the second data may include M (M is an integer of 2 or more) bits and N (N > M integer) bits, so that the number of “1” and “0” is the same in the N-bit data, or the number of high level and low level is the same in NRZI notation. A data recording method, wherein the data is recorded after conversion. 15. The data recording method according to claim 14, wherein the pit to be deformed based on the second data is:
A data recording method, wherein only a pit having a predetermined length in a track extension direction is used. 16. The data recording method according to claim 14, wherein the pit to be deformed based on the second data is:
A data recording method, wherein pits are formed by predetermined data repeated in a predetermined cycle of the first data. 17. The data recording method according to claim 14, wherein the pit to be deformed based on the second data is:
A data recording method, wherein the length of the specific pattern portion of the first data in the track extension direction is only a predetermined pit. 18. The data recording method according to claim 14, wherein the second data is recorded at a predetermined position on the optical recording medium. 19. The data recording method according to claim 11, wherein said optical recording medium is an optical disk, and said second data is recorded in a lead-in area. 20. The data recording method according to claim 14, wherein the first data is encrypted and recorded, and the second data is an encryption key for decrypting the data. A data recording method characterized by being information. 21. A light source for outputting a recording laser beam, an optical modulator for modulating the recording laser beam emitted from the light source based on first data, M (M is an integer of 2 or more) The second data of the bits
The number of “1” and “0” becomes the same number, or the number of the high level and the low level becomes the same number in the NRZI notation, N (N
Data conversion means for converting the data into integer (> M integer) bits of conversion data, and the modulated recording laser beam output from the optical modulator is modulated based on the conversion data from the data conversion means. An optical deflector for deflecting a recording laser beam in a direction substantially orthogonal to a scanning direction on the optical recording medium; and condensing the modulated recording laser beam output from the optical deflector on the optical recording medium. A data recording device comprising: an objective lens; 22. The data recording apparatus according to claim 21, wherein the pit deformed based on the conversion data is a length of a pit formed based on the first data in a track extension direction. A data recording device, wherein only the pits have a predetermined length. 23. The data recording apparatus according to claim 21, wherein the pit deformed based on the converted data is a pit formed by predetermined data repeated at a predetermined cycle in the first data. A data recording device characterized by the above-mentioned. 24. The data recording apparatus according to claim 21, wherein the pits deformed based on the conversion data are only pits of a specific pattern portion of the first data having a predetermined length in a track extending direction. A data recording device, characterized in that: 25. The data recording apparatus according to claim 21, wherein the second data is recorded at a predetermined position on the optical recording medium. 26. A data recording apparatus according to claim 25, wherein said optical recording medium is an optical disk, and wherein said second data is recorded in a lead-in area. 27. A data recording method according to claim 21, wherein said first data is recorded after being encrypted, and said second data is an encryption key for decrypting the data. A data recording device, which is information. 28. M bits (M is an integer of 2 or more)
(N> M integer) bits, and in the converted N bits, the number of “1” and “0” is the same, or the high level and the low level are expressed in NRZI notation. A data reproducing method for performing an inverse conversion of converted and recorded data and reproducing the converted data so that the number becomes the same number, wherein a parity check is performed on the N-bit data, and when there is no error, the inverse conversion is performed. A data reproducing method, wherein a predetermined M bits are assigned or an error flag is assigned when an error is detected. 29. M bits (M is an integer of 2 or more)
(N> M integer) bits, and in the converted N bits, the number of “1” and “0” is the same, or the high level and the low level are expressed in NRZI notation. A data reproducing method for performing reverse conversion of data recorded by conversion so as to have the same number, and reproducing the data, wherein the number of "0" or "1" of the N bits is N / 2 or N It is checked whether the number of bits “0” and “1” is the same, and when there is no error, the above-mentioned inverse conversion is executed. When an error is detected, a predetermined M bits are assigned or an error flag is added. A data reproducing method. 30. M bits (M is an integer of 2 or more)
(N> M integer) bits, and in the converted N bits, the number of “1” and “0” is the same, or a high level and a low level in NRZI notation. What is claimed is: 1. A data reproducing apparatus for performing an inverse conversion of converted and recorded data and reproducing the converted data so that the numbers become the same, wherein: an error check unit for performing a parity check on the N-bit data; , When there is no error,
Control means for executing the inverse conversion and assigning predetermined M bits and / or adding an error flag when an error is detected. 31. M bits (M is an integer of 2 or more)
(N> M integer) bits, and in the converted N bits, the number of “1” and “0” is the same, or the high level and the low level are expressed in NRZI notation. A data reproducing apparatus for converting data recorded by conversion and performing reverse conversion to reproduce the data so that the number becomes the same number, wherein the number of "0" or "1" of the N bits is N / 2 or N An error checking means for checking whether the number of bits “0” and “1” is the same and performing an error check; and, if the error check indicates that there is no error, the inverse conversion is performed. Control means for assigning predetermined M bits or adding an error flag when detected. 32. A track comprising a plurality of pits formed based on first data and lands between the pits, wherein the plurality of pits are arranged in a width direction of the track based on second data. Wherein the second data is obtained by converting M (M is an integer equal to or greater than 2) bits into N (N> M integer) bits, The light is characterized by being converted so that the number of "1" and "0" is the same in the N bits, or the number of high level and low level is the same in NRZI notation. recoding media. 33. The optical recording medium according to claim 32, wherein the pits displaced from the center in the track width direction based on the second data have a predetermined length in the track extension direction. An optical recording medium comprising only pits. 34. The optical recording medium according to claim 32, wherein the pits displaced from the center of the track in the width direction based on the second data are repeated at a predetermined cycle of the first data. An optical recording medium comprising pits formed by predetermined data. 35. The optical recording medium according to claim 32, wherein the pit displaced from the center in the width direction of the track based on the second data is a pit of a specific pattern portion of the first data. An optical recording medium, wherein the length in the extension direction is only a predetermined pit. 36. The optical recording medium according to claim 32, wherein said second data is recorded at a predetermined position. 37. The optical recording medium according to claim 36, wherein the optical recording medium is a disk recording medium, and wherein the second data is recorded in a lead-in area. 38. The optical recording medium according to claim 32, wherein said first data is recorded after being encrypted, and said second data is an encryption key for decrypting the encrypted data. An optical recording medium characterized by being information. 39. A track comprising a plurality of pits formed based on first data and lands between pits, wherein the plurality of pits are deformed based on second data. Wherein the second data is obtained by converting M (M is an integer of 2 or more) bits into N (N> M integers) bits, and the N bits are “1”. An optical recording medium which has been converted so that the number of "0" is the same, or the number of high level and low level is the same in NRZI notation. 40. The optical recording medium according to claim 39, wherein the pits deformed based on the second data are only pits having a predetermined length in the track extension direction. An optical recording medium characterized by the above-mentioned. 41. The optical recording medium according to claim 39, wherein the pit deformed based on the second data is formed by predetermined data repeated at a predetermined cycle in the first data. An optical recording medium having pits. 42. The optical recording medium according to claim 39, wherein the pit deformed based on the second data has a length of a specific pattern portion of the first data in a track extending direction. An optical recording medium having predetermined pits. 43. The optical recording medium according to claim 39, wherein said second data is recorded at a predetermined position. 44. The optical recording medium according to claim 43, wherein said second data is recorded in a lead-in area. 45. The optical recording medium according to claim 39, wherein said first data is recorded after being encrypted, and said second data is an encryption key for decrypting the data. An optical recording medium characterized by being information.