JP2001023178A - Optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a physical format of optical disk that is suited for a big capacity. SOLUTION: A wobble part AWT that moves in a zigzags direction in the radius direction of an optical disk and a non-wobble part NWT that does not move in a zigzag direction are provided at the track of an optical disk P1 with a track WT1 for recording user data, the combination of the wobble part AWT and the non-wobble part NWT is used, sub-information that is data other than the user data is recorded on the track, and the sub-information is set to conversion sub-information having been converted according to a specific conversion rule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a physical format of a rewritable optical disk using a phase change medium or a magneto-optical (MO) medium, or a write-once (write-once) optical disk using a dye-based medium. In particular, the present invention relates to a physical format suitable for handling a large amount of data such as image data and audio data.

[0002]

2. Description of the Related Art DVDs (digital video disks), MO disks, and CDs (compact disks) have been commercialized as large-capacity storage media used in computers. Also, with the spread of computers, users often edit data stored in a storage medium, and the need for a storage medium on which data can be changed or additionally recorded has been increased.

A rewritable storage medium on which a user can change data many times is a DVD-RAM (randomly readable and writable memory) using a phase change medium, an MO disk using an MO medium, CD-RW (Re
Writable). A write-once (write-once) storage medium on which a user can write data only once is a CD-R using a dye-based medium. In these storage media, addresses for recognizing the positions where the data are written on these storage media are stored in advance.

On the DVD-RAM or MO disk, an ID section (Identification section) for indicating an address is provided separately from a section in which user data is stored. In addition, a wobble address method based on FM modulation (frequency modulation) is used for address management in the CD-RW and CD-R. Here, wobble means meandering, and indicates a structure in which tracks on the disk meander in the radial direction of the disk. That is, in a CD-RW or CD-R, an address is stored by changing the frequency of a wobble (meandering) of a track. Therefore, in a CD-RW or CD-R, user data and an address are superimposed and stored along a track.

[0005]

However, these prior arts have the following problems. That is, the above D
Since a VD-RAM or MO disk needs to be provided with an ID part separately from an area in which user data is stored, there is a problem that the area use efficiency of the disk surface deteriorates.

Further, since the structure of the disk surface is different between the area where user data is stored and the ID portion, manufacturing such a disk requires a complicated manufacturing process and makes it difficult to manufacture the disk. There is a problem. Particularly, in the DVD-RAM, since the ID portions are arranged in a staggered manner, the manufacturing process is further complicated.

In the above-mentioned CD-RW and CD-R,
Since the address corresponds to the frequency of the wobble, the disk reader needs to read a signal (wobble) of a different frequency in order to read the address,
There is a problem that the configuration of the reading device is complicated.

Further, since the frequency of the wobble of the track is changed in accordance with the address value, the length of the track required to represent an address differs for each address value, and data write control becomes complicated. Problem.

Further, since the above-mentioned method of making the address correspond to the frequency of the wobble stores the address by FM-modulating the wobble, the required C
There is a problem that the / N (Carrier to Noise) ratio is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an advantage in that the area utilization efficiency of the disk surface is good, the disk is easy to manufacture, the configuration of the disk reading device is simple, and An object of the present invention is to provide an optical disk in which data writing control is simple and the required C / N ratio is small.

[0011]

According to a first aspect of the present invention, there is provided a rewritable optical disk such as a phase change medium or a magneto-optical medium or a write-once type optical disk such as a dye-based medium having a track for recording user data. In the optical disc, the track is provided with a wobble portion meandering in a radial direction of the optical disc and a non-wobble portion that does not meander, and the user is provided by using a combination of the wobble portion and the non-wobble portion. An optical disc characterized in that sub-information, which is data other than data, is stored in the track, and the sub-information is converted sub-information converted according to a predetermined conversion rule.

According to a second aspect of the present invention, the logical value of each bit constituting the sub-information is expressed as a set of the wobble part and the non-wobble part, and the logical value of either the wobble part or the non-wobble part is expressed. One length is bit is a logical value "
2. The optical disk according to claim 1, wherein the optical disk is different in a case of taking a logical value of "1" from a case of taking a logical value of "0". The logical value is expressed as a set of the wobble part and the non-wobble part, and the length of the wobble part differs depending on whether a bit takes a logical value “0” or a bit takes a logical value “1”. When the length of the non-wobble portion is a bit whose logical value is “0”
3. The optical disk according to claim 2, wherein the value of the optical disk is equal to the value of the logical value "1".

According to a fourth aspect of the present invention, the length of the non-wobble portion is set to a length of one or two cycles of meandering in the wobble portion. An optical disc according to any one of the above.

The invention according to claim 5, wherein the conversion rule converts the sub-information before conversion into the conversion sub-information composed of even-numbered bits. It is an optical disk of the description. The invention according to claim 6 is the optical disc according to claim 5, wherein the conversion rule converts 2 bits in sub-information before conversion into conversion sub-information composed of 4 bits. .

According to a seventh aspect of the present invention, the conversion sub-information includes the same number of bits having a logical value “0” and the same number of bits having a logical value “1”. 4. The optical disc according to 1.

[0016] In the invention described in claim 8, the sub-information is:
8. The optical disk according to claim 1, wherein the address is an address in the track.

The invention according to claim 9 is the optical disc according to any one of claims 1 to 8, wherein the track is divided into a plurality of zones in a radial direction of the optical disc.

The invention according to claim 10 is the optical disk according to claim 9, wherein the sub-information is a zone address of the zone.

According to an eleventh aspect of the present invention, there is provided the optical disk according to the tenth aspect, wherein the meandering phases of the wobble portions of adjacent tracks in the zone coincide with each other.

According to a twelfth aspect of the present invention, there is provided the optical disk according to the eleventh aspect, wherein user data is recorded on both a land portion and a groove portion of the track.

According to a thirteenth aspect of the present invention, the length of the wobble part and the non-wobble part is an integral multiple of one cycle of meandering in the wobble part. 4. The optical disc according to 1.

[0022]

FIG. 1 is a diagram showing a configuration of an optical disc P1 according to a first embodiment of the present invention. Tracks are provided on the surface of the optical disc P1, and sub-information is recorded in advance along the tracks. User data is superimposed and stored on the track on which the sub information is recorded.

Here, the sub information is information other than the user data, and a typical example thereof is an address. In addition, various pieces of parameter information related to the disc are also included in the sub-information.

The optical disk P1 shown in the figure is, for example, a rewritable optical disk such as a DVD-RAM using a phase change medium, a CD-RW, and an MO disk using an MO medium.
Alternatively, it is a write-once optical disk such as a CD-R using a dye medium.

As shown, a wobble track WT1 is provided on the surface of the optical disk P1, and user data is recorded along the wobble track WT1. Here, the wobble means a meandering, and indicates a structure in which the track is meandering in the radial direction of the optical disc P1. However, this wobble track WT1 has a wobble portion AWT and a non-wobble non-wobble portion NWT as shown in the figure. These wobble parts AWT
And the non-wobble portion NWT, the sub-information is stored in the track.

FIG. 2 is an enlarged view showing the detailed structure of the wobble track WT1 on the optical disk P1.
A meandering track groove T is provided on the surface of the optical disk P1, and the bottom of the track groove T is called a groove G, and a portion sandwiched between adjacent track grooves T is called a land L. The undulation (meandering) of the track groove T is called a wobble.

When recording user data on the optical disk P1 using the land & groove recording method,
Recording marks P are formed on both the land L and the groove G. In order to read recorded data, light H is incident from the bottom surface of the optical disc P1.

The wobble of the track groove T is used to represent sub-information of user data recorded on the optical disc P1. The sub information is, for example, information indicating a position of user data recorded along the track groove T, that is, an address. Therefore, the optical disk P1
In the above, the user data and the sub-information are superimposed and stored along the track groove T.

FIG. 3 shows that the sub information is stored in the wobble of the track groove T, that is, based on the sub information data,
FIG. 11 is a diagram showing a procedure for forming a wobble track WT1 on the optical disc P1. First, the sub-information data 1 is converted into the converted sub-information data 3 by the conversion table 2.
Further, the converted sub-information data 3 is MAM-modulated,
Based on the MAM-modulated waveform data, the track groove T
A wobble is formed. Here, the MAM modulation means an improved AM modulation that has been improved so that it can be applied to the optical disc of the present invention.

FIG. 4 shows an example of the conversion table 2. As described above, the conversion table 2 receives the sub information data 1 and outputs the converted sub information data 3. Both the sub information data 1 and the converted sub information data 3 are "0".
And "1".

According to the conversion table shown in FIG. 4, arbitrary 2-bit sub-information data is converted into 4-bit conversion sub-information data. In any case, the converted conversion sub-information data includes the same number of “0” and “1”. That is, 4
Two bits of the converted sub-information data are "0" and the remaining two bits are "1".

FIG. 5 shows an example of the MAM modulation. That is, by the MAM modulation, “0” included in the converted sub-information data is converted into a waveform shown in FIG.
"1" included in the converted sub-information data is converted into a waveform shown in FIG.

FIG. 5 corresponding to the conversion sub-information data "0"
The waveform shown in (a) is composed of a wobble period A0 having a meandering period of 10 periods and a non-wobble period B0 not meandering. The length of the non-wobble period B0 is set to the meandering length of two cycles in the wobble period A0. The meandering period T in the wobble period A0
d is always constant.

FIG. 5 corresponding to the conversion sub information data "1"
The waveform shown in (b) is composed of a wobble period A1 having a meandering period of 14 periods and a non-wobble period B1 not meandering. The length of the non-wobble period B1 is set to the meandering length of two cycles in the wobble period A1. The meandering cycle in the wobble period A1 is always constant, and the conversion sub-information data "
It is equal to the meandering period Td in the wobble period A0 included in the waveform corresponding to “0”.
The length of the non-wobble period B1 included in the waveform corresponding to "1" is equal to the length of the non-wobble period B0 included in the waveform corresponding to the converted sub-information data "0".

Therefore, if the lengths of A0, B0, A1, and B1 are expressed in units of a common meandering period Td, (A0, B0) = (10, 2) (A1, B1) = (14, 2)

A wobble track WT1 is formed by forming a wobble portion AWT and a non-wobble portion NWT in the track groove T of the optical disk P1 based on the waveform generated by the MAM modulation. The above settings, for example, the lengths of the wobble periods A0 and A1 are as follows:
It is not limited to 10 periods or 14 periods, and can be set arbitrarily.

The above-mentioned MAM modulation method is a digital modulation type of AM modulation (amplitude modulation), OOK (On Off Keyin).
This is an improved AM modulation system which utilizes g) and is modified so that it can be applied to the physical format of the optical disk of the present invention. A modulation signal by this modulation method is DC-free, and is extremely practical.

Further, in this MAM modulation system, "0" and "1" are represented by the presence or absence of a wobble (meandering). That is, "0" and "1" are distinguished by the length of the section where the wobble continues, so that it is not necessary to change the wobble frequency as in the conventional FM modulation method.

Further, in the conventional FM modulation method, a large C / N (Carrier) is used to detect the frequency of the wobble.
to noise (carrier-to-noise) ratio is required, but if the MAM modulation method according to the present invention is used, it is only necessary to detect the presence or absence of a wobble, so that a large C / N ratio as in the prior art is required. There is no.

Further, in the MAM modulation method shown in the above embodiment, the length of the non-wobble period B0 included in "0" is equal to the length of the non-wobble period B1 included in "1". That is, the length is two cycles of B0 = B1 = wobble. Therefore, it is not necessary to change the non-wobble period depending on whether the value of the sub-information is "0" or "1", and only the wobble period needs to be changed. Can be realized.

The length of the non-wobble periods B0 and B1 is set to one or two periods of the wobble in consideration of the influence on the PLL circuit that synchronizes with the wobble in order to read the wobble. Is appropriate. However, since these set values may be determined according to the system to which the present invention is applied, the present invention is not limited to the above set values.

When the above conversion table and MAM modulation are used, all the conversion sub-information data has the same length on the track. That is, in the present embodiment, the lengths of the waveforms of the converted sub-information data “0” and “1” are different, and accordingly, the lengths on the track are also different. However, the conversion sub-information data always has a set of 4 bits, and "
Since the same number of "0" and "1" are included, the length of the 4-bit track on the track is the same regardless of the value of the converted sub-information data. Control of data writing is simplified.

That is, the conversion table converts 2-bit sub-information data into 4-bit conversion sub-information data, and converts the converted sub-information data after converting any sub-information data. In, the frequency of occurrence of “0” and “1” is 1: 1.

FIG. 6 shows an example of conversion from sub-information data to converted sub-information data. As shown in FIG. 6, if certain sub-information data is composed of 8 bits, the converted sub-information data obtained by converting this sub-information data using the conversion table has 16 bits, and 8 bits of the converted sub-information data are " 0 ", and the remaining 8 bits become" 1 ".

Specifically, in Example 1 shown in FIG. 6, 8-bit sub-information data (01111111) is converted into 16-bit converted sub-information data (110010101010101010) by the conversion table shown in FIG.
That is, the first two bits (01) of the sub information data are
The conversion table shown in FIG. 4 is converted into 4-bit conversion sub-information data (1100). Subsequent 2-bit sub-information data (11) is converted into 4-bit conversion sub-information data (1010). Is done.

If the entire length of the bit string of the converted sub information data is expressed in units of a wobble period Td, the total length = the length of “0” + the length of “1” = 8 bits × (10Td + 2Td) ) +8 bits × (14Td + 2Td) = 224Td.

In the example 2 shown in FIG. 6, the 8-bit sub information data (10000000) is converted into the 16-bit converted sub information data (00 00) by the conversion table shown in FIG.
11010101010101). That is, the leading two bits (10) of the sub-information data are converted into 4-bit conversion sub-information data (0011), and the subsequent two-bit sub-information data (00) is converted into four-bit conversion sub-information. It is converted into information data (0101).

When the entire length of the bit string of the converted sub information data is expressed in units of a wobble period Td, the total length = the length of “0” + the length of “1” = 8 bits × (10Td + 2Td) ) +8 bits × (14Td + 2Td) = 224Td, which is the same length as in Example 1.

That is, the length on the track for expressing one piece of sub-information is always constant, which makes it very easy to put the optical disc of the present invention into practical use.

Next, a second embodiment of the present invention will be described with reference to FIG. In the optical disk P2 shown in FIG. 7, a wobble disk provided on the surface of the optical disk P2
The track WT2 is divided into a plurality of zones 21, 22, ..., 2n. The optical disc P2 has a ZC
AV (Zoned Constant Angular Velocity) or ZC
The LV (Zoned Constant Linear Velocity) format is adopted.

In the optical disc P2, the zone addresses of the respective zones 21, 22,..., 2n are stored in the wobble track WT2 belonging to each zone as sub-information. That is, since the same zone address is stored in all wobble tracks in the same zone, the same zone address is also stored in adjacent tracks in the same zone. Therefore, the phases of the wobble of the adjacent wobble track WT2 are substantially the same.

With such a configuration, a constant track pitch can always be ensured even if the track has a wobble (meandering), so that the wobble method and the land & groove recording method can be used together. Also, in reading a wobble, detection can be performed without crosstalk from an adjacent track.

As in the above embodiments, A0, B
If all of 0, A1, and B1 are set to integral multiples of the wobble period Td, disc creation becomes extremely easy, and the PLL control system in the wobble reading device is
It can be operated stably.

[0054]

According to the first aspect of the present invention, the sub-information other than the user data can be superimposed on the user data without lowering the disk format efficiency. According to the invention described in claim 2 or 3, the optical disk according to the present invention can be realized extremely easily.
According to the fourth aspect of the invention, when configuring the PLL control system based on the wobble signal, the PLL control system can be kept stable. According to the invention described in any one of the fifth to seventh aspects, the length of a track required to express one piece of sub-information can be always kept constant.

According to the eighth aspect of the invention, an address which is a representative example of the sub information can be superimposed on the user data without lowering the disk format efficiency. According to the ninth aspect of the present invention, ZCA
It can be applied to V to ZCLV format. According to the invention described in claim 10, the present invention
The present invention can also be applied to a method of superimposing a zone address for each zone on user data on a disk. According to the eleventh aspect, the track pitch in each zone can always be kept constant, so that a wobble can be detected without crosstalk from an adjacent track. According to the twelfth aspect, the present invention can be applied to land & groove recording. As a result, land and groove recording, which was previously impossible with the wobble method, becomes possible.
The capacity of the disk can be increased. According to the thirteenth aspect of the present invention, the manufacture of the disk becomes extremely easy. Further, when configuring the PLL control system based on the wobble signal, the PLL control system can be kept stable. As described above, according to the present invention, since the overhead of the disk can be minimized, a physical format of the optical disk suitable for increasing the capacity can be provided.

[Brief description of the drawings]

FIG. 1 is an optical disc P according to a first embodiment of the present invention.
1 is a conceptual diagram showing a configuration of FIG.

FIG. 2 is an enlarged view showing a structure of a wobble track WT1 formed on a surface of an optical disc P1.

FIG. 3 is a diagram showing a procedure for storing sub-information in a wobble track.

FIG. 4 is a diagram illustrating an example of a conversion table of sub information data.

FIG. 5 is a diagram illustrating a waveform representing bits of converted sub-information modulated by the MAM modulation method.

FIG. 6 is a diagram illustrating an example of conversion from sub information data to converted sub information data.

FIG. 7 is an optical disc P according to a second embodiment of the present invention.
FIG. 2 is a conceptual diagram showing a configuration of FIG.

[Explanation of symbols]

P1, P2 Optical discs WT1, WT2 Wobble track (track) AWT Wobble section NWT Non-wobble section T Track groove L Land G Groove P Recording mark H Light 1 Sub-information data 2 Conversion table 3 Conversion sub-information data 21, 22, ..., 2n zone

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[Procedure amendment]

[Submission date] January 19, 2000 (2000.1.1)
9)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6

Claims (13)

[Claims] 1. A rewritable optical disk such as a phase-change medium or a magneto-optical medium or a write-once optical disk such as a dye-based medium having a track for recording user data, wherein the track has a radial direction of the optical disk. A wobble portion that is meandering and a non-wobble portion that is not meandering are provided, and sub-information that is data other than the user data is stored in the track using a combination of the wobble portion and the non-wobble portion. An optical disc, wherein the sub-information is converted sub-information converted according to a predetermined conversion rule. 2. The logical value of each bit constituting the sub information is expressed as a set of the wobble part and the non-wobble part, and the length of one of the wobble part and the non-wobble part is represented by a bit. 2. The optical disc according to claim 1, wherein a difference between when takes a logical value "0" and a case when takes a logical value "1". 3. The logical value of each bit constituting the sub-information is expressed as a set of the wobble part and the non-wobble part.
, And the length of the non-wobble portion is the same between the case where the bit takes the logical value “0” and the case where the bit takes the logical value “1”. The optical disk according to claim 2, wherein 4. The optical disc according to claim 1, wherein the length of the non-wobble portion is set to a length of one or two cycles of meandering in the wobble portion. . 5. The optical disk according to claim 1, wherein the conversion rule converts the sub-information before conversion into converted sub-information composed of even-numbered bits. 6. The optical disk according to claim 5, wherein the conversion rule converts 2 bits in the sub-information before conversion into converted sub-information composed of 4 bits. 7. The optical disk according to claim 5, wherein the conversion sub-information includes the same number of bits having a logical value “0” and the number of bits having a logical value “1”. 8. The optical disk according to claim 1, wherein the sub information is an address in the track. 9. The optical disk according to claim 1, wherein the track is divided into a plurality of zones in a radial direction of the optical disk. 10. The optical disk according to claim 9, wherein the sub information is a zone address of the zone. 11. The optical disk according to claim 10, wherein meandering phases of wobble portions of adjacent tracks in said zone coincide with each other. 12. The optical disk according to claim 11, wherein user data is recorded on both a land portion and a groove portion of said track. 13. The optical disk according to claim 1, wherein the length of the wobble portion and the non-wobble portion is an integral multiple of one meandering period in the wobble portion.