JP2001319341A - ID format method for optical recording medium - Google Patents

Abstract

(57) [Problem] To provide an ID format method capable of performing mastering with one beam while reducing the influence on track servo in an optical recording medium of a land-groove recording method. SOLUTION: Among auxiliary information recorded in advance on a recording medium, common information having the same content as an adjacent track, such as a sector mark and a sector number, is recorded on a groove, and is different from an adjacent track such as a track number. The unique information as the content is recorded at a position shifted from the groove. Preferably, the code modulation method used for recording the common information and the code modulation method used for recording the auxiliary information are different. Alternatively, the common information is recorded by a wobble that makes the groove meander in the radial direction of the recording medium, and the unique information is recorded by pits formed by interrupting the groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a land-groove recording optical system which is formed concentrically or spirally on a disk-shaped recording medium and records information on both grooves and lands alternately formed in the radial direction. The present invention relates to an ID format method in which auxiliary information such as a sector mark, a sector number, and a track number is nonvolatilely recorded on a recording medium by physical deformation of an optical recording substrate.

[0002]

2. Description of the Related Art A disk-shaped optical recording medium such as an optical disk or a magneto-optical disk has a groove (groove) for positioning a recording position in a radial direction, that is, a track servo. If the depth of the groove is set to a certain relationship (for example, λ / 8) with the wavelength of the irradiation light, a track error can be detected from the reflected light.
That is, by detecting a deviation from the track (in the radial direction) and applying the track servo based on the detected output, it is possible to perform recording at the center of the groove. Alternatively, it can be recorded at the center of the land between the grooves. Conventionally, groove recording or land recording is performed on one of the groove and land, but land-groove recording on both the groove and land has been proposed as one method of high-density recording in recent years. I have.

In order to record and reproduce information, in addition to the above-described positioning signal, auxiliary information such as recording address information and PLL lock information for address reading is recorded in advance in a recording unit of several kilobytes. It is necessary to keep. Generally, such a recording part of the auxiliary information is called an ID part, and the auxiliary information may be called an ID. The non-volatile recording of auxiliary information by physical deformation of the optical recording substrate is called an ID format.

As shown in FIG. 1, the circumferential direction (track) of an optical recording medium is divided into about 10 to 100 sectors, and an ID portion is provided at the head of the sector. Following the ID part, a data part only for the groove is provided. The ID part includes a sector mark (SM), VFO1, AM, ID1,
It is divided into areas such as VFO2, AM, ID2, and PA. ID1 further includes a sector number (SN), a track number (TN), and a CRC (SN + TN error correction code). Note that ID2 is an ID for preventing reading errors.
The same content as 1 is duplicated.

As an ID format method, in the case of groove recording, there is a method shown in FIG. 2A or 2B.
In the method of FIG. 2A, isolated pits are formed by interrupting the groove, and the position of the pit center or pit end corresponds to the information of 0 or 1. In the method of FIG. 2B, the groove is meandering (wobble) in the radial direction of the disk.
The wobble direction is made to correspond to the information of 0 or 1.
Also, in order to correctly perform recording / reproduction even when 0 or 1 continues in the recording data, after appropriate code conversion,
Recording is also conventionally performed. The method of FIG. 2A or 2B is an example in the case of groove recording, and in the case of land / groove recording, auxiliary information (ID) for land recording.
It is necessary to devise a way to record

FIGS. 3A and 3B show an example of a method of recording an ID portion in the case of land / groove recording. FIG.
In the method (a), the ID portion is formed of pits and is recorded at a boundary position between an adjacent groove and a land, so that one auxiliary information is shared by the adjacent groove track and the land track. . As shown in FIG. 3A, the ID1 is located between the groove G1 and the lands on both sides.
And ID2 are provided. Similarly, ID3 and ID4 are provided between the groove G2 and the lands L1 and L2 on both sides, and ID3 and ID4 are provided between the groove G3 and the lands on both sides. Thus, all tracks can be identified.

[0007]

[Table 1] That is, since at least one of the IDs between the adjacent lands read by the passing track is different from the other tracks, all the tracks can be identified. FIG.
For the sake of simplicity, the description has been given of the case where the ID is single-written, but actually, the same content is recorded twice in the ID of the figure,
Preventing reading errors has also been performed conventionally.

In the method shown in FIG. 3B, land / groove recording is realized by wobble recording. The basic concept is the same as the method shown in FIG. 2B, but here, by wobbling only one wall of the groove, all tracks can be identified in the same manner as in Table 1.

[0009]

SUMMARY OF THE INVENTION As described above, the conventional I
The D format has the following disadvantages.
First, in the method shown in FIG. 2A or 2B, the track servo is likely to be unstable because the track error signal is shifted in the ID section. For a sudden change in track error, the servo state does not deviate because the track actuator follows only gradually, but when the actuator is swung to follow, it overlaps with external vibration and the ID part is erroneously read. Is more likely to occur.

In the method shown in FIG. 3A or 3B,
Although the deviation of the track error as described above is relatively small,
The mastering process for forming such a groove becomes complicated. That is, in order to manufacture a mold for injection-molding a substrate of a recording medium, it is necessary to perform cutting using two laser beams in the step of cutting the glass master coated with the resist with a laser beam. As a result, it is disadvantageous for increasing the density of the recording medium (reducing the track pitch). More recently, studies have been made to perform cutting using an electron beam instead of a laser beam in order to further increase the density, but it is more difficult to perform cutting using two electron beams. .

The present invention has been made in view of the above-mentioned conventional problems, and provides an ID format method capable of performing mastering with one beam while reducing the influence on a track servo in an optical recording medium of a land-groove recording system. The purpose is to provide.

[0012]

SUMMARY OF THE INVENTION An ID formatting method according to the present invention records information on both grooves and lands formed concentrically or spirally on a disk-shaped recording medium and alternately formed in the radial direction. In an optical recording medium of the land-groove recording method, a sector mark, a sector number,
An ID format method for non-volatile recording of auxiliary information such as a track number by physical deformation of an optical recording medium, wherein common information having the same content as an adjacent track, such as a sector mark and a sector number, is provided on the groove. , And unique information such as a track number having a different content from the adjacent track is recorded at a position shifted from the groove.

[0013] By recording the auxiliary information of the ID portion in the above-described manner, the length of the deviation of the track error signal (the length of the unique information) is reduced to several bytes, and the influence on the track servo is reduced. can do. Preferably,
The common information and the unique information are each divided into a plurality of areas, and recorded so that at least one area of the common information is inserted between the areas of the unique information.

It is preferable that a code modulation method used for recording common information and a code modulation method used for recording auxiliary information be different. The crosstalk from the ID section is a problem with the original information, while the land track uses crosstalk to read the recorded information. Therefore, adopt a different code modulation method according to the required specifications of both. As a result, the reliability of recording / reproduction is improved. Alternatively, the common information may be recorded by a wobble that makes the groove meander in the radial direction of the recording medium, and the unique information may be recorded by pits formed by interrupting the groove.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows an ID portion of a recording medium recorded by the ID format method according to the first embodiment of the present invention. The auxiliary information to be recorded in the ID section includes a sector mark (SM), a VFO, a sector number, a band number, a track number, an error correction code (CRC), and the like. Such auxiliary information often records the same content about twice in order to improve read reliability, and has a total information amount of about 40 to 80 bytes.

In order to make the recording density of the inner track and the outer track of the disk-shaped recording medium as uniform as possible, the band number should be set to tens to tens of bands in the radial direction. Is the serial number of each band when divided. By increasing the number of sectors per track for the outer band, the recording density is made as uniform as possible on the inner and outer bands.

In this case, the same track number can be used in different bands. That is, in the same band, the track number increases sequentially from zero, but when the band moves to the next band, the track number returns to zero. In this way, the track number can be represented by a length of about 2 bytes.

Normally, one CRC is provided for a sector number, a band number, and a track number.
In this embodiment, a unique CR is used for the track number.
C is provided. Then, the auxiliary information having a different content from the adjacent track, that is, the unique information, is composed of the track number and its CR.
C only. These pieces of information can be represented by 3 to 4 bytes. Remaining sector mark (SM), VFO,
Information such as a sector number and a band number is common information having the same contents as the adjacent track.

As shown in FIG. 4, in the ID format method of the present embodiment, the ID is divided into an ID common part 42, an ID unique part 1 (43) and an ID unique part 2 (44). I
Common information is recorded in the D common unit 42, and the ID unique unit 1
(43) and ID unique part 2 (44) record unique information. The ID common part 42 is formed in the center of the groove G similarly to the data part 41, and the ID unique part 1 (43) and the ID
The unique part 2 (44) is formed on the boundary with the adjacent land L. More specifically, the ID unique part 1 (43) is formed on the boundary with one adjacent land L on the inner peripheral side or the outer peripheral side, and the ID unique part 2 (44) is formed on the boundary with the other adjacent land L. Is formed.

By recording the ID (auxiliary information) as described above, the length of the track error (the length of the unique information) can be reduced to several bytes, and the influence on the track servo can be reduced. If the track error signal when reading original information is held by the sample and hold circuit,
The influence on the track servo can be further reduced.
Such a sample and hold circuit cannot generate a hold signal unless at least the sector mark at the head of the ID section is read. Therefore, when the entire auxiliary information including the sector mark is recorded at a position shifted in the radial direction from the center of the groove as in the conventional example shown in FIG. 2, accurate hold cannot be expected.

FIG. 5 is a circuit diagram showing an I-mode according to a second embodiment of the present invention.
The recording track of ID by the D format method is shown. In this embodiment, in order to improve reliability, each ID
Are recorded twice. Reading data is usually V
This is performed after the FO unit draws in the PLL circuit and creates a read clock. Also in the case of reading twice, the VFO is provided at two places and the PLL is pulled in again. By returning the VFO section and the second sector number and track number for the redrawing to the center of the groove and sampling the track error signal again, the period during which the track error signal is held can be shortened.

FIG. 6 shows an ID according to a third embodiment of the present invention.
The format method is shown. In this embodiment, the code modulation method used for recording the common information (ID common part) 62 is different from the code modulation method used for recording the unique information (ID unique part) 63. That is, in recording the common information 62, 1 is converted to a code in which 1s and 0s do not continue.
NRZI (non-return-to-zero-inv)
erted recording) recording. On the other hand, in recording of the unique information 63, recording is performed by 4/15 conversion in which information is read from the fourth position from the largest signal amplitude.

The 1/7 conversion + NRZI recording method has a high recording density in the circumferential direction and can record necessary information with a short recording length. However, the bit end corresponds to 1, and the zero crossing of the differential signal is performed. Reads information based on presence or absence,
Crosstalk from adjacent tracks has a weak disadvantage. For example, as shown in FIG. 7A, the zero cross 7 which does not originally occur in the waveform of the differential signal due to the influence of the adjacent pit 71
2 and 73 occur. For this reason, the possibility of erroneous reading of the unique information increases.

On the other hand, recording by the 4/15 conversion has an advantage that the recording density in the circumferential direction is low, but it is strong against crosstalk. For example, as shown in FIG. 7 (b), since information is read from the fourth position from the largest signal amplitude, if the level of crosstalk due to adjacent bits is at or below the fifth position, it is ignored and no error occurs. .

As described above, a recording method by 4/15 conversion that is strong against crosstalk is adopted only for unique information that may cause crosstalk, and 1/7 conversion + NRZI recording method is adopted for other information that does not cause crosstalk. By doing so, the efficiency (the ID section is made as short as possible) and the reliability (I
D reading error).

FIG. 8 is a circuit diagram showing an I-mode according to a fourth embodiment of the present invention.
ID of recording medium recorded by D format method
Part is shown. In this embodiment, the common information (ID common portion) is recorded by a method of wobbling the groove as shown in FIG. 2B, and the unique information (ID unique portions 1 and 2) is recorded.
Is recorded by pits formed by interrupting the groove as shown in FIG. If the common information is also recorded by pits, it causes a track count error for high-speed access. Also,
The signal amplitude of the land portion to be read using the crosstalk from the adjacent groove is smaller than the signal amplitude of the cue portion, and the possibility of a reading error increases. On the other hand, in the present embodiment, since the common information is recorded by wobble, the signal amplitudes of both are substantially equal, and the possibility of a reading error is reduced.

Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, but can be implemented in various forms.

[0028]

As described above, according to the ID formatting method of the present invention, auxiliary information is divided into common information and unique information, and the common information is recorded on the groove, and only the unique information is recorded on the groove. Since it is recorded at a position shifted from
The length by which the track error signal shifts (the length of the unique information) can be shortened, and the influence on the track servo can be reduced. In this way, the mastering for recording the ID portion of the land-groove recording type optical recording medium can be performed by one beam while minimizing the influence on the track servo, so that the density of the optical recording medium is further increased. Can be contributed to.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a recording area of a conventional optical recording medium.

FIG. 2 is a diagram showing an example of a conventional ID format method for an optical recording medium.

FIG. 3 is a diagram showing another example of a conventional ID format method for an optical recording medium.

FIG. 4 is a diagram showing an ID part of a recording medium recorded by the ID formatting method according to the first embodiment of the present invention.

FIG. 5 is a diagram showing recording tracks of IDs by an ID formatting method according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating an ID formatting method according to a third embodiment of the present invention.

FIG. 7 shows 1/7 conversion + in the third embodiment of the present invention;
FIG. 4 is a diagram illustrating a difference between NRZI recording and recording by 4/15 conversion.

FIG. 8 is a diagram showing an ID part of a recording medium recorded by an ID format method according to a fourth embodiment of the present invention.

[Explanation of symbols]

 42, 62, 82 Common information 43, 44, 63, 83, 84 Unique information 85 Wobble 86 Pit G Groove L Land

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Claims (5)

[Claims] 1. A land-groove recording type optical recording medium which is formed concentrically or spirally on a disk-shaped recording medium and records information on both grooves and lands alternately formed in a radial direction. An ID format method for non-volatile recording of auxiliary information such as a sector number and a track number by physical deformation of an optical recording substrate, wherein the auxiliary information has the same contents as an adjacent track such as a sector mark and a sector number. The information is recorded on the groove, and the unique information such as a track number, which has a different content from the adjacent track, is recorded at a position shifted from the groove.
Formatting method. 2. The method according to claim 1, wherein the common information and the unique information are each divided into a plurality of areas, and recorded so that at least one area of the common information is inserted between the areas of the unique information. Format method of the optical recording medium of the above. 3. The optical recording medium according to claim 1, wherein a code modulation method used for recording the common information is different from a code modulation method used for recording the auxiliary information.
D format method. 4. The apparatus according to claim 1, wherein said common information is recorded by wobbles which meander the groove in a radial direction of a recording medium, and said unique information is recorded by pits formed by intermittently intersecting said groove. Formatting method of the optical recording medium described in the above. 5. The method according to claim 1, wherein
An optical recording medium on which auxiliary information such as a sector mark, a sector number, and a track number is recorded by a D format method.