JP2002222524A - Optical disk device, and data randomizing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record write data different for each writing on a medium in order to maintain a good tracking characteristic, and prevent the alteration of the medium even when the same user data are written in an adjacent track or in the physically same place. SOLUTION: Optional sheet data for randomization are added to original data to be recorded on a disk. 1-bit randomizing data are decided by calculation using 1-bit original data or sheet data and plural bit past randomizing data. In descrambling, the descrambling is carried out without needing any sheet data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device such as a DVD, and more particularly to a data scrambling method for recording data on a medium in the optical disk device.

[0002]

2. Description of the Related Art Generally, in a rewritable optical disk such as a DVD-RAM, data is written on a track of the disk by generating a recording mark by the power of light. In addition, data is read using the difference between the reflectance of light at the recording mark and that at other locations. In a DVD-RAM, a groove called a groove is formed on a disk, and the density is increased by writing data in both a groove (land) and a non-groove portion (groove).

In a recording / reproducing apparatus using a disk-type recording medium, control for accurately positioning a head on a track is called tracking. In DVD-RAM,
A land and a groove are formed by applying a minute vibration called a wobble, and tracking is performed using this. However, if the same data is written in an adjacent track, there is a problem that the tracking signal becomes weak and the tracking is easily lost.

[0004] In a DVD that handles images, sounds, and the like, it often happens that the same data such as silent parts is written in large quantities.
In order to solve this problem, various measures have been taken so that even if a large amount of the same data is written by the user, the write data of the adjacent tracks does not become the same. For example, as disclosed in Japanese Patent Application Laid-Open No. Hei 6-274885, there is a method of changing the start of a sector from a mark called a pit or from a place other than a mark called a land for each track. In addition, as described in Standard-ECMA-272, D
In the VD-RAM, an M sequence (random sequence) is generated using the ID information of each frame as a seed, added to user data, and then written to a disk. Such randomization of data is generally called scrambling.

On the other hand, in the field of optical communication, a method called guided scrambling has been used for the purpose of producing a run length limited code having a flat frequency characteristic and suitable for optical communication. This is to create a run length limited code by adding data with a sufficiently large space to the beginning of the data to create many types of data, and randomizing each of them to create data that is close to the desired characteristics. You choose one. For such technology, for example, “Co
des for Mass Data Storage Systems ”KASImmin
k, Shannon Foundation Publisher, 1999. The dissertation states, “Polynomials for Guid
ed Scrambling Line Code ”, IEEE JOURNALON SELECTED
AREAS IN COMMUNICATIONS, Vol.13, NO.3, APRIL, 1995
There is a description.

[0006]

By the way, in the case of a rewritable optical disk, if the same data is written many times in the same physical location (sector) on the optical disk medium, the medium deteriorates and new data is written. There is a problem that the previous data remains and appears as noise.

[0007]

In the scrambling method according to the present invention, in order to solve the above problem, data is scrambled using an arbitrary seed. Preferably, arbitrary seed data for randomizing is added to the original data to be recorded on the disc. One-bit randomized data is determined by an operation using one-bit original data or seed data and a plurality of bits of past randomized data.

In accordance with another aspect of the present invention, there is provided a descrambling method that does not require seed data. More specifically, at the time of data reproduction, 1-bit de-randomized data is determined by an operation using randomized data of a plurality of bits.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
First, a first embodiment will be described with reference to FIGS.

FIG. 3 is a schematic block diagram showing the configuration of the optical disk device of the present embodiment. The embodiment described below does not limit the present invention. The optical disk device is not limited to a storage device used in a computer system as in the present embodiment, but also includes a stationary image connected to a television, a sound recording / reproducing device. A recording / reproducing device such as a device, a portable video camera, or a portable audio reproducing device may be used.

In FIG. 3, a host interface (host I / F) 311 controls data transfer between the optical disk device and a host computer such as a personal computer (not shown). The scramble circuit 309 is
Randomize the data. Error correction coding circuit 307
Adds an error correction code to the randomized data. The run length restriction encoding circuit 305 modulates the data to which the error correction code is added according to a predetermined rule, and converts the data into data that can be recorded on the optical disc 301 as a recording medium. The recording / reproducing amplifier 303 receives the encoded data from the run length limiting encoding circuit 305, and converts the data into a voltage waveform suitable for the recording / reproducing head 302. The recording / reproducing head 302 converts the received voltage waveform into an optical laser, and uses the power of light to
Write a mark on 1.

When reading data, the recording / reproducing head 30
2 irradiates a laser beam onto the optical disc 301, reads data by using reflected light, and converts the read information into an electric signal using a difference in reflection intensity between the marked and non-marked light.
This electric signal is appropriately amplified by the recording / reproducing amplifier 303 and then output to the data reproducing circuit 304. The data reproducing circuit 304 converts the read analog signal into a digital information sequence of 0 and 1.

The obtained data string is subjected to demodulation in the run-length limited code decoding circuit 306 in a manner opposite to that of the run-length limited coding circuit 305. The error correction circuit 308 obtains an error position and an error value based on the error correction code added by the error correction encoding circuit 307, and corrects the error. The data corrected for the error is restored to the original data by the descrambling circuit 310. In the optical disk device, data recording and reproduction are performed according to the above procedure.

The scramble circuit 309 will be described in detail. FIG. 4 is a detailed block diagram of the scramble circuit 309.

The user data transmitted from the host I / F 311 is added to the fixed random sequence generated by the M-sequence generator 401 by the EOR circuit 402 and then input to the guided scrambler 403.

FIG. 5 is a detailed circuit diagram of the M-sequence generator 401. Reference numerals 502 to 515 denote registers for storing data in 1-bit units, and perform shift operations in synchronization with user data. 501 is an exclusive OR circuit. In the initial state, only the register 515 is set to 1 and the registers 502 to 514 are set to 0. In the present embodiment, an M-sequence generator based on a 15th-order polynomial shown in Expression 1 is assumed. Hereinafter, all the polynomials used in this embodiment are polynomials on GF (2), and “+” indicates exclusive OR.

[0017]

(Equation 1)

The sequence generated by the M-sequence generator 401 is a pseudo-random sequence having a period of 2 ＾ 15-1 = 32767. In the present embodiment, the M-sequence generator 4
01 is not always necessary, and only the guided scrambler 403 may be used. However, in this embodiment, the M-sequence generator 401 is also used in order to improve the random performance.

In the guided scrambler 403, first, as shown in FIG. 9, 8-bit data is added to the head of the data. This is arbitrary 8-bit data, and may be data created based on the writing time or the like, or may be a value that is incremented by one each time writing is performed by an 8-bit increment counter. . These 8 additional bits become an initial value (seed) for randomization. In this embodiment, since 8-bit data is added, “00000000” to “11111111”
Up to 2 ＾ 8 = 256 randomizations can be performed. That is, when the same user data is recorded in the same physical location, the probability that the actually written data becomes the same is 1/256. The same applies to the case where the same user data is written to an adjacent track.

By performing the randomization in this way, it is possible to prevent the optical disc 301 from being deteriorated and to reduce the tracking error. The data to be added does not need to be 8 bits, and may be more or less. The additional bit (initial value) does not need to be added to the head of the user data, and may be placed anywhere in the user data. After adding the additional bits,
It is generated as a different series for each initial value. In the present embodiment, the additional data is placed at the head which can be randomized most efficiently. However, when there is information to be read before descrambling such as ID information, it is better to insert additional bits after the ID information.

FIG. 6 is a detailed circuit diagram of the secondary scramble circuit 405. Reference numerals 601 to 604 denote exclusive OR circuits, and reference numerals 605 to 612 denote registers for storing data in 1-bit units. Registers 605 to 612
It is set to 0 in the initial state. The secondary scramble circuit 405 performs a shift operation in synchronization with input data. With this circuit, scrambling according to Equation 2 is performed.

[0022]

(Equation 2)

Here, bi is the secondary scramble circuit 4
05, the data of the i-th bit, ci-j, before entering the 05 is the j of the data of the i-th bit output from the secondary scramble circuit.
This is the data before the bit. As can be seen from this equation, c
i is formed from 1-bit data before scrambling and a plurality of bits of past data after scrambling.

After the data is scrambled in this manner, it is sent to the error correction coding circuit 307.

Next, the descrambling circuit 310 will be described in detail.

FIG. 7 is a detailed block diagram of the descrambling circuit 310. FIG. 8 is a detailed circuit diagram of the secondary descrambling circuit 704 of FIG. Registers 801 to 808 store data in 1-bit units. 809 to 812
Is an exclusive OR circuit. Secondary descramble circuit 7
Similarly to the secondary scramble circuit 405, the shift operation is performed in synchronization with the input data.

Next, the operation of the descrambling circuit 310 will be described.

The data whose error has been corrected by the error correction circuit 308 is input to the secondary scramble circuit 704 of the guided descramble circuit 703. The secondary scramble circuit 704 performs descrambling shown in Expression 3.

[0029]

(Equation 3)

Where bi is the descrambled i
The bit-th user data, ci-j, is the error correction circuit 3
08 is the data of the j-th bit before the i-th bit. As can be seen from this equation, when descrambling is performed, descrambling can be performed even if the initial value of scrambling is not known. The error correction circuit 30
If an uncorrectable error occurs in step 8, the error spreads by 8 bits in the descrambled user data. However, the error propagation is only 8 bits and does not spread any further.

Next, as shown in FIG. 9, the random data deletion circuit 705 deletes the eight additional bits added by the random data addition circuit 404.

The M-sequence generator 701 includes the M-sequence generator 40
1 and shown in FIG. By adding the same items with the exclusive OR 402, the user data is decoded.

In this embodiment, the scramble circuit is constituted by using a shift register for bit shifting. However, this may be realized by an equivalent circuit which operates in byte units.

Also, in this embodiment, an 8-bit primitive polynomial

[0035]

(Equation 4)

The guided scrambling was performed by using, but the polynomial used here may be any primitive polynomial, and the general form of the polynomial may be used.

[0037]

(Equation 5)

On the other hand, the scramble circuit can be realized in FIG. 1 and the descrambling circuit can be realized in FIG. Here, ai is 1 or 0. When 1, the signal line is connected, and when 0, the signal line is not connected.

In this embodiment, the scramble circuit 309 / descramble circuit 310 is composed of an error correction encoding circuit 307 / decoding circuit 308 and a host I / F 31.
1, but run length limited coding 305 /
It may be provided between the decoding circuit 306 and the error correction coding circuit 307 / decoding circuit 308. Further, in the present embodiment, the M-sequence generator 401/701 is arranged closer to the host I / F 311 than the guided scramble circuit 403 / descrambling circuit 703.
1/701 may be arranged closer to the optical disc 301 than the guided scramble 403 / descrambling 703.

Next, as a second embodiment, a case where the guided scramble described in the first embodiment is applied to a DVD format will be described in further detail.

FIG. 14 is a schematic block diagram of a DVD device. Reference numeral 311 denotes an interface for controlling input / output of data with the host device, and reference numeral 1406 denotes a microcomputer for controlling the system. Reference numeral 1401 denotes the user data provided by the interface 311;
ID to which additional information necessary for recording such as ID is added
The adders 1402a and 1402b are memories (RAM) for temporarily storing data. Numeral 309 denotes a scrambler for randomizing data. This scrambler is the one described in the first embodiment.
Includes a fixed-seed M-sequence generator and a guided scrambler. 307, an error correction encoding circuit for adding an error correction code to the scrambled user data;
Reference numeral 5 denotes an encoder for converting user data to which an error correction code has been added into a run length limited code suitable for recording on the optical disk 301; 302, a pickup for recording / reproducing data on / from the optical disk 301; This is a spindle motor to be driven. Also, 1404
Is a servo for controlling the optical pickup 302 and the like.

Reference numeral 304 denotes a read channel for performing waveform equalization processing, binarization, and generation of a synchronous clock of an analog reproduction signal read from the optical disk 301. 306 is
Decoder for decoding the read run length limited code, 308
Is an error detection and correction circuit that detects an error based on the error correction code added by the error correction encoding circuit 307 and corrects the error. Reference numeral 310 denotes a descrambling circuit shown in the first embodiment, which cancels the randomization performed by the scrambler 309 and restores the original user data. The fixed seed M-sequence generator and the guided descrambler including. An ID deletion unit 1407 deletes additional information necessary for recording such as the ID added by the ID addition unit 1401 and sets only user data.

Next, the write format of the user data will be described with reference to FIGS.

Input from the interface 311
For example, 2048-byte user data includes identification address information of data such as ID (ID section 1001, IED section 1).
002, reserve unit 1003) Error detection code (EDC: Error Dtection Cod) of 11 bytes and 4 bytes
e) 1006 is added by the ID adder 1401.

Next, a 1-byte guided scramble seed 1004 is added and scrambled. The main data (user data) 1 is scrambled.
005 and the error detection code 1006 only. ID
Is not scrambled. The 2060-byte data is added with a 4-byte error detection code (EDC: Error Dtection Code) 2064.
172 bytes x 12 rows. This is called a "data sector". Next, as shown in FIG. 12, the 16 "data sectors" are grouped into one ECC block, and the cross Reed-Solomon error correction code is encoded. The redundant bytes in the vertical direction are called PO, and the redundant bytes in the horizontal direction are called PI.

Next, as shown in FIG. 13, 16 rows of PO are allocated to 16 sectors for each row, and 172 bytes × 1
Reassemble to 2 + 1 rows. This is called PO interleaving, and the data of 172 bytes × 12 + 1 rows is called “recording sector”. The “physical sector” shown in FIG. 11 is a sector after modulation by 8/16 conversion by adding a synchronization signal (SYNC code) 1101 to the head of each “91” of the “recording sector” 1102. In addition, EDC1 shown in FIG.
006 is a check code added to the data sector 2060 bytes before scrambling. Using the EDC code 1006, it is checked whether scramble is correct, and whether error correction has been performed after error correction.

The writing format of the user is as follows:
As shown in FIG. 28, a seed may be added to the head. In this case, 11 bytes (1001, 1002, 1003) of identification address information of data such as ID such as ID and reserve, and 4 bytes of detection code (EDC: Error Dtection Code) are also scrambled similarly to the data. In the case of this format, it is possible to prevent deterioration of the medium in the ID section. In the case of employing the format shown in FIG. 28, as shown in FIG. 29, a descrambler 1408 dedicated to the ID section is placed immediately after signal reproduction processing by PRML or the like so that the ID can be read before ECC decoding There is a need.

The operation of the DVD device shown in FIG. 14 will be described below. First, a processing procedure at the time of recording will be described with reference to FIG.

An ID and additional information are added to the data input from the interface 311 by the ID adding circuit 1401 (step 1501).
2a is temporarily stored (step 1502). Next, RA
Data is read from M1402a (step 150).
3) The signal is scrambled by the scramble circuit 309 (step 1504), and the error correction encoding circuit 307
Is added with an error correction code (step 150).
5), scrambled data, PO redundancy byte, P
Both the I redundant bytes are stored in the RAM 1402a (step 1506). Next, this data is stored in the RAM 1402a.
The PO interleave is performed while reading from the data (step 1507), and the encoding circuit 305 converts the code into a run length limited code (step 1508). The data converted into the run length limited code controls the optical pickup 302 via the laser driver 1405 and is recorded on the optical disk 301.

If one ECC block of data is normally recorded on the optical disc 301, the process ends. If the recording fails for some reason on the way,
Writing the same data in the same location will cause media degradation.
For this reason, re-scrambling is performed by changing the seed, and the process is repeated. Step 1 in the flow of FIG.
The processing after 503 will be redone.

Next, the processing procedure during reproduction will be described with reference to FIG.

At the time of reproduction, data is read by the optical pickup 302, and binarization and generation of a synchronous clock are performed in the read channel 304 (step 1601). The decoding circuit 306 decodes the code from the run length limited code (step 1602).
While performing deinterleaving, the data is temporarily stored in the RAM 1402b (step 1603). Error correction is performed via the RAM 1402b (step 1604), descrambling is performed (step 1605), and the descrambled data is stored in the RAM 1402b again (step 1606). Further, in step 1606, the RAM 140
2 is read out (step 1607),
The EDC code 1006 checks whether the scramble is correct, checks whether the error has been corrected and corrects the error, deletes additional information such as an ID and a seed, and outputs the result to the interface 311 (step 1608). ).

With the configuration of the first embodiment, since the scramble is released after the error correction process is completed, the error correction capability does not deteriorate due to the error propagation of the guided scramble. Further, since the configuration is close to that of a current DVD device, device development is easy.

In the first embodiment, a seed is added for every 2 Kbytes of one-sector user data. However, it is also possible to perform guided scrambling with one seed for each ECC block to reduce the seed storage area. 1 ECC
A method of continuously performing one guided scramble processing on blocks and a method of performing guided scramble processing on one ECC block using the same seed in each sector can be considered. In addition, since guided scrambling causes error propagation, considering that the data can be rescued as little as possible when the error cannot be corrected, this embodiment will be described in the case where the user performs a scramble process rather than the error correction coding. As described above, it is desirable that scrambling be performed along the byte sequence of the error correction codeword. By doing so, when a large burst error occurs and error correction becomes impossible, descrambling can be performed only by generating one byte error propagation from the last bit of the burst error.

Next, a third embodiment will be described with reference to FIGS. In the present embodiment, the error correction coding 307 and the scramble processing 30 as shown in FIG.
The order of 9 is different from the first and second embodiments.

FIG. 18 is a block diagram of an optical disk device according to the third embodiment. The optical disk device according to the present embodiment is configured in the same manner as the optical disk device according to the second embodiment shown in FIG. 14, but the arrangement of the scramble circuit 309 and the descrambling circuit 310 is different from that of the second embodiment. . Hereinafter, the operation of the optical disc device according to the present embodiment will be described with reference to FIGS.

First, a processing procedure at the time of recording will be described with reference to FIG.

The data input from the interface 311 is added with an ID and additional information in an ID adding circuit 1401 (step 1901), and the RAM 1402
is temporarily stored in a (step 1902). Next, RAM
Data is read from 1402a (step 190).
3) The error correction code is calculated by the error correction coding circuit 307 (step 1904), and the error correction code portion is written into the RAM 1402a (step 190).
5).

Next, PO interleaving is performed while reading data from the RAM 1402a (step 19).
06), a scramble process is performed on the read data (step 1907). Thereafter, the data is converted into a run length limited code by the encoding circuit 305 (step 1908), and the optical pickup 302 is controlled via the laser driver 1405, and is recorded on the optical disk 301.

When one ECC block of data is normally recorded on the optical disk 301, the process is terminated. However, if the recording fails for some reason in the middle,
If the same data is written in the same place, the medium will be degraded. Therefore, the seed is changed, re-scrambling is performed, and the processing is performed again. In the flowchart of FIG. 19, the processing after step 1906 is repeated.

In the present embodiment, when rewriting is performed, it is not necessary to recalculate the error correction code, and the load at the time of rewriting can be greatly reduced. Further, since it is not necessary to store the scrambled data in the RAM, the number of accesses to the RAM can be reduced and the speed can be increased.

Next, a processing procedure at the time of reproduction will be described with reference to FIG.

At the time of reproduction, data is read by the optical pickup 302, and binarization and generation of a synchronous clock are performed in the read channel 304 (step 2001). The decoding circuit 306 decodes from the run length limited code (step 2002), and the descrambling circuit 310 performs a descrambling process (step 2003). The data subjected to the descrambling processing is subjected to processing reverse to that of PO interleaving and PO deinterleaving, and
b (step 2004). Further RA
Error correction is performed on the data stored in the M1402b (step 2005), and the data is read from the RAM 1402b (step 2006).
According to 6, it is checked whether the scramble is correct, and whether the erroneous correction has been made after the error correction.
After this, the additional information such as ID and the seed are deleted,
The data is output to the interface 311 (step 2007).

In this embodiment, since the error correction process is performed after descrambling as described above, a random one is generated by the error propagation of the guided scramble.
Since a byte error becomes a two-byte error and increases the number of errors, there is a problem that the number of errors that can be corrected decreases due to the error correction capability of the error correction code.
In addition, since guided scramble causes error propagation, considering that data can be rescued as little as possible when error correction is impossible, in the case of performing scramble processing on the optical disk medium side than error correction coding, this embodiment will be described. As shown, it is desirable to scramble along the sequence of bytes to be written. By doing so, when a large burst error occurs and error correction becomes impossible, descrambling can be performed only by generating one byte error propagation from the last bit of the burst error.

Next, a fourth embodiment will be described with reference to FIGS.

In this embodiment, data is written on an optical disk in the physical format shown in FIG. In this embodiment, it is assumed that EFM Plus currently used in DVD is used as the run length restriction code. EFM Pl
us is a (d, k) = (2,10) code, the shortest mark and space length are 3 channel bits, the longest mark and space length are 11 channel bits. In FIG. 21, the sync pattern indicated by “SY” is the bit string shown in FIG.

The bit string shown in FIG. 23 is represented in the NRZI format.
“0” means that the state is kept as it is. This sync pattern includes a mark or space for 14 channel bits that does not exist in the data section for clear distinction from data. This one type of sync pattern is written following a 1-byte scramble seed. The 256 scrambled seeds are classified into 26 types as shown in FIG.
Seeds appearing in one position are limited to one. For example, the seed at the first position of the physical sector is selected from seedGr0, that is, nine seeds 0 to 8.

FIG. 25 shows a block diagram of the optical disk device of the present embodiment.

First, a processing procedure at the time of data recording will be described.

An ID and additional information are added to the data input from the interface 311 by an ID adding circuit 1401 to form a data sector. The data sector is temporarily stored in the RAM 1402a. Next, RAM
Data is read from 1402a, a data sector of 172 bytes in the horizontal direction is divided into 91 bytes and 81 bytes, and a scramble process is performed using one seed selected from the seeds included in the classification shown in FIG. 24 and RAM 1402 as shown in FIG.
Write back to a.

The error correction codes PO and PI are calculated by the error correction coding circuit 307 for the data written back to the RAM 1402a, and the RAM
1402a. After that, PO interleaving is performed while reading data from the RAM 1402a,
The coding circuit 305 converts the code into a run length limited code, and inserts a fixed pattern sync pattern as shown in FIG. 21 to constitute a physical sector. The data processed as described above controls the optical pickup 302 via the laser driver 1405, and is recorded on the optical disk 301.

At the time of reproduction, data is read by the optical pickup 302 and
Value conversion and synchronous clock generation are performed. Decoding circuit 306
, A descrambling circuit 2501 performs a descrambling process and searches for a fixed pattern sync pattern. When the sync pattern is found, the descrambled seed data immediately before the sync pattern is checked, and the read data is stored in the RAM 14 according to the recording format shown in FIG.
02b. The data stored in the RAM 1402b is subjected to error correction and descrambled. Thereafter, the EDC code 1006 checks whether or not the scramble is correct, and whether or not the error has been corrected after the error has been corrected. The additional information such as the ID and the seed are deleted, and the data is output to the interface 311. Is done.

By performing such processing, scrambling is performed in units of 91 bytes of user data, and error propagation due to scrambling does not propagate out of the 91 bytes. In addition, there is an advantage that it is possible to uniquely identify which position in the recording sector the read data corresponds to. Further, the number of additional bits required for the SYNC pattern and the scramble seed is 26 bits per sector as compared with the current DVD.
It can be done by adding about 6 bytes.

According to the present embodiment, only a single sync pattern needs to be prepared, and there is no need to prepare a plurality of sync patterns to know the position in the sector. Therefore, there is an advantage that the design of the run length limited code becomes very easy. It is desirable that the scrambled seed is placed before the fixed sync pattern. In an optical disk, a high-pass filter is used at the time of reproduction because of a large amount of low-frequency noise. Therefore, distortion is likely to occur immediately after a long mark or space. Since the fixed sync pattern needs to be clearly separated from other recording codes, a long mark or space that does not generally appear in the recording code is often used. Therefore, it is desirable to place the scrambled seed before the fixed sync pattern.

Next, a fifth embodiment will be described with reference to FIGS. This embodiment is different from the second embodiment in that scrambling is performed before storing the data in the RAM.

FIG. 26 is a diagram showing the configuration of the present embodiment. The disk device of this embodiment has a scramble circuit 2
601 and a scramble circuit 2602 are provided. The scramble circuit 2601 is the scramble circuit described in the first embodiment.

The operation of the disk device according to this embodiment will be described.

At the time of recording, the data input from the interface 311 is added with an ID and additional information in an ID adding circuit 1401. The data added with the ID and the additional information is descrambled by the scramble circuit 2601, and then temporarily stored in the RAM 1402a. Thereafter, the error correction coding circuit 307 stores the RAM 1402a
Calculate the error correction code for the data stored in
The PO redundant byte and the PI redundant byte are stored in the RAM 1402a. While reading data from RAM 1402a, PO
Interleaving is performed. Thereafter, the encoding circuit 305
Converts the PO interleaved data to a run length limited code. The converted data is supplied to the laser driver 140
5, the optical pickup 302 is controlled and recorded on the optical disk 301.

When the data of one ECC block has been normally recorded on the optical disk 301, the process ends.

However, if the recording fails for some reason during the recording of the data, writing the same data in the same place will cause deterioration of the medium. Therefore, in this case, the seed is changed, re-scrambling is performed, and data writing is performed again. In that case, the data stored in the RAM 1402a is scrambled by the scramble 2602. The scrambled data is stored again in the RAM 1402a, and an error correction code is added again by the error correction coding circuit 307. The data to which the error correction code is added is subjected to PO interleaving, run length limited coding, and then written to the optical disc 301 again.

FIG. 27 is a diagram showing a scramble circuit 2602 of this embodiment. This circuit includes a switch 2701
In the direction of the first 8-bit seed, and then controlled in the “0” direction. From the seed direction, an appropriate 8-bit seed bit string is input each time. By taking an exclusive OR for each bit of the M-sequence generated by this circuit and the scrambled data stored in the RAM, it is possible to re-scramble with a different seed. At the time of reproduction, reproduction can be performed in the same manner as in the second embodiment.

[0082]

According to the present invention, arbitrary seed data is added to the original data to be recorded on the disk, and the data is scrambled. Therefore, a plurality of scrambles can be performed by selecting the seed data. Therefore,
Even if a large amount of the same data is written in the adjacent track, it is possible to prevent the write data in the adjacent track from becoming the same data. Further, even if the same data is written in the same physical location, different write data can be obtained, and the medium does not deteriorate.

According to the present invention, the descramble data of one bit is determined by the operation using the scramble data of a plurality of bits. Therefore, it is not necessary to know the seed data at the time of descrambling, and the descrambling is performed by the same simple procedure. it can.

Further, according to the present invention, 1-bit descrambling data is determined by an operation using n-bit scramble data. When the n-bit scrambled data has a length of s bits, the error of the descrambling data is only s bits larger than the error of the scrambled data, and it does not occur that the entire data cannot be descrambled.

Furthermore, according to the present invention, scrambling and scrambling of fixed seeds having a long period are used together, so that the randomness of data can be sufficiently ensured.

Further, according to the present invention, the scrambling is performed before generating the error correction code, and the descrambling is performed after decoding the error correction code, so that the error propagation characteristics due to the scramble do not deteriorate the decoding characteristics of the error correction code.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a scramble circuit according to the present invention.

FIG. 2 is a block diagram showing a descrambling circuit of the present invention.

FIG. 3 is a schematic block diagram of an optical disc device according to the first embodiment of the present invention.

FIG. 4 is a detailed block diagram of a scramble circuit according to the first embodiment of the present invention.

FIG. 5 is a detailed circuit diagram of an M-sequence generator according to the first embodiment of the present invention.

FIG. 6 is a detailed circuit diagram of a secondary scramble circuit according to the first embodiment of the present invention.

FIG. 7 is a detailed block diagram of a descrambling circuit according to the first embodiment of the present invention.

FIG. 8 is a detailed circuit diagram of a secondary descrambling circuit according to the first embodiment of the present invention.

FIG. 9 is a conceptual diagram of the first embodiment of the present invention.

FIG. 10 is a data sector format diagram.

FIG. 11 is a diagram showing a physical sector format according to the second embodiment of the present invention.

FIG. 12 is a recording format diagram according to the second embodiment of the present invention.

FIG. 13 is a conceptual diagram showing PO interleaving.

FIG. 14 is a system block diagram according to a second embodiment of the present invention.

FIG. 15 is a processing flowchart during recording according to the second embodiment of the present invention.

FIG. 16 is a processing flowchart at the time of reproduction according to the second embodiment of the present invention.

FIG. 17 is a schematic block diagram of an optical disc device according to a third embodiment of the present invention.

FIG. 18 is a block diagram of an optical disc device according to a third embodiment of the present invention.

FIG. 19 is a processing flowchart during recording according to the third embodiment of the present invention.

FIG. 20 is a processing flowchart at the time of reproduction according to the third embodiment of the present invention.

FIG. 21 is a physical format diagram according to the fourth embodiment of the present invention.

FIG. 22 is a diagram illustrating grouping of seeds according to the fourth embodiment of the present invention.

FIG. 23 is a diagram illustrating a fixed sync pattern according to the fourth embodiment of the present invention.

FIG. 24 is a diagram illustrating a recording format according to a fourth embodiment of the present invention.

FIG. 25 is a block diagram of an optical disc device in a bristle board according to a fourth embodiment of the present invention.

FIG. 26 is a block diagram of an optical disc system according to a fifth embodiment of the present invention.

FIG. 27 is a detailed block diagram of a scramble circuit according to a fifth embodiment of the present invention.

FIG. 28 is a data sector format diagram.

FIG. 29 is a system block diagram of a modification of the second embodiment of the present invention.

[Explanation of symbols]

 101-104: 1-bit register 105-109: exclusive OR circuit 201-204: 1-bit register 205-209: exclusive OR circuit 301: optical disk 302: optical head 303: recording / reproducing amplifier 304: data reproducing circuit 305 : Run length limited coding circuit 306: run length limited code decoding circuit 307: error correction coding circuit 308: error correction circuit 309: scramble circuit 310: descramble circuit 311: host I / F 401: M sequence generator 402: Exclusive OR circuit 403: Guided scrambler 404: Random data addition circuit 405: Secondary scramble circuit 501: Exclusive OR circuit 502 to 515: 1-bit register 601 to 604: Exclusive OR circuit 605 to 612: 1 Bit register 701: M-sequence generator 702: Exclusive OR circuit 703: Guided descrambler 704: Secondary scramble circuit 705: Random data addition circuit 801 to 808: 1-bit register 809-812: Exclusive OR circuit

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Jiichi Miyamoto 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. F-term in Hitachi, Ltd. System Development Laboratory (reference) 5D044 BC04 CC04 DE17 DE48 EF05 EF10 5D090 AA01 BB04 CC02 GG16

Claims (19)

[Claims] 1. A method for recording data on a recording medium using light,
In an optical disc apparatus for reading data recorded on the recording medium by utilizing a difference in light reflectance, the user data is scrambled by adding an arbitrary seed to input user data, An optical disk device characterized by writing on the top. 2. An optical disk reproducing apparatus for reading data recorded on a recording medium by utilizing a difference in light reflectance, wherein randomized data scrambled using an arbitrary seed is scrambled without using a seed. An optical disc reproducing apparatus for canceling. 3. Recording data on a recording medium using light,
What is claimed is: 1. A data randomization method used in an optical disc apparatus for reading data recorded on a recording medium by utilizing a difference in light reflectance, wherein randomization is performed on original data to be recorded on the recording medium. Data seeding method, and 1-bit randomized data is determined by an operation using the 1-bit original data or seed data and a plurality of bits of past randomized data. 4. Recording data on a recording medium using light,
In an optical disk apparatus for reading data recorded on the recording medium by utilizing a difference in light reflectance, seed data for randomizing is added to original data to be recorded on the recording medium, and Bit randomized data,
An optical disc apparatus characterized in that it is determined by an operation using the 1-bit original data or seed data and a plurality of bits of past randomized data. 5. A data randomization canceling method used in an optical disc apparatus for reading data recorded on a recording medium by utilizing a difference in light reflectance, wherein the method is performed by using a plurality of bits of randomized data. A data randomization cancellation method, wherein 1-bit randomization cancellation data is determined. 6. An optical disk reproducing apparatus for reading data recorded on a recording medium by utilizing a difference in light reflectance, wherein the data is recorded on the recording medium in a randomized manner. An optical disc reproducing apparatus, wherein 1-bit de-randomized data is determined by an operation using a plurality of bits of randomized data. 7. An optical disk medium used in an optical disk reproducing apparatus for reading data recorded on a recording medium by utilizing a difference in light reflectance.
Seed data for performing randomization is added to the original data, and 1-bit randomized data is determined by an operation using the 1-bit original data or seed data and a plurality of bits of past randomized data. An optical disc medium on which the generated randomized data is recorded. 8. The optical disk device according to claim 1, wherein
An optical disc apparatus, comprising: generating a fixed randomized bit string having a longer period than the randomization method used for scrambling; and performing exclusive OR operation on the original data and each bit. 9. The optical disk reproducing apparatus according to claim 6, wherein a fixed randomized bit string having a longer period than a randomization cancellation method for determining said randomization cancellation data is generated, and said descrambling data and An optical disc reproducing apparatus for performing an exclusive OR operation for each bit. 10. The optical disk reproducing apparatus according to claim 2, wherein a fixed randomized bit string having a longer period than a scrambling method used for said scrambling is generated, and said randomized data and exclusive OR for each bit are generated. An optical disc reproducing apparatus for performing calculations. 11. The optical disk device according to claim 1, wherein the data to be written on the recording medium is written with an error correction code added, and after the randomization is performed, the data is error correction encoded. Characteristic optical disk device. 12. An optical disk reproducing apparatus according to claim 6, wherein data read from said recording medium is added with an error correction code, and randomization is canceled after error correction. 13. The optical disk device according to claim 11, wherein when the user data is re-scrambled,
An optical disc reproducing apparatus characterized in that re-scrambling is performed by taking an exclusive OR for each bit of M-sequence data selected by scrambling only seed data and the user data. 14. An optical disk apparatus according to claim 4, wherein said seed data is placed immediately before a fixed sync pattern, and usable seed data is predetermined according to a position in a sector. . 15. The optical disk device according to claim 13,
An optical disc device characterized in that data is scrambled in an order of an error correction codeword byte to be decoded first. 16. An optical disk device according to claim 1, wherein data to be written on said optical disk is written with an error correction code added thereto, and is subjected to error correction coding before performing said randomization. Optical disk device. 17. An optical disk reproducing apparatus according to claim 4, wherein the data read from said optical disk is added with an error correction code, and the error is corrected after the randomization is released. 18. The optical disk device according to claim 16, wherein the scramble order of the data is the order of bytes recorded on the medium. 19. The optical disk device according to claim 4, wherein the scrambled seed data is placed in the first byte of a sector format.