JP2000285524A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rewrite type optical disk which can be made higher in format efficiency and have data recorded at an arbitrary position without any waste. SOLUTION: The optical disk 10 where data are recorded and reproduced by error correction blocks by using a light beam has a land track 13 and a groove track 14 arranged by turns adjacently and embossment pits 16 formed on the border between the land track 13 and groove track 14 so as to recognize the positions of the error correction blocks; when the groove depth DG of the groove track 14 is so set that λ/(4n)<DG<λ/(2n), the depth DP of the embossment pits is so set that DG<DP<λ/(2n), where λ is the wavelength of a light beam and (n) is the refractive index of a medium where the light beam is propagated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk capable of recording and reproducing data and an optical disk apparatus for recording and reproducing data on and from the optical disk.

[0002]

2. Description of the Related Art In a rewritable optical disk capable of repeatedly recording data at an arbitrary position on a disk and reproducing data at an arbitrary position, data is generally recorded in sector units. In this case, sector address information and error-correction-encoded data are recorded in each sector.

On the other hand, a recently standardized 120 mm
A large-capacity rewritable optical disc called a DVD-RAM having a large diameter requires an error correction data obtained by performing error correction coding over a plurality of sectors instead of a sector unit in order to improve the error correction capability of the data. Recording can be performed in units of correction blocks (ECC blocks). The same applies to a DVD-ROM which is a read-only optical disk, in which data is recorded in units of error correction blocks consisting of 16 sectors including 2048 bytes of data per sector. In the DVD-ROM, the error correction coding is applied to the address information of the error correction block and the sector in the same manner as the data, so that the structure is extremely resistant to errors.

In a DVD-RAM, address information in sector units is recorded in advance as emboss pits on a disk, and one error correction block is generated in a plurality of sectors (16 sectors) when data is recorded. In this way, address information is always obtained in sector units,
For example, even if the optical head is erroneously moved to an adjacent track during recording, there is an advantage that the damage of the erroneous recording is only one sector and the seek time is shortened. Further, since a periodic signal corresponding to the cycle of the sector can always be obtained from the address information of the sector during recording and reproduction, it is possible to control the spindle motor for rotating the optical disk according to the periodic signal.

[0005]

By the way, the conventional DV
In a method of recording address information in units of sectors, such as a D-RAM, in addition to an area of address information (header field) in each sector, a disk rotation speed fluctuation or eccentricity at the time of data recording / reproduction causes a disk. Buffer area to accommodate the actual sector length change above,
For example, a buffer area for dealing with random shift of the recording position and deterioration of the start and end when using the phase change recording method,
The area other than the area for recording the original data increases, which causes the format efficiency to decrease. For this reason, in order to secure a sufficient recording capacity, it is necessary to increase the recording density by that much, and if the recording density is kept constant, there is a problem that the recording capacity is reduced by that much.

On the other hand, as a method for recording data without forming address information in sector units on an optical disc,
For example, as employed in CD-R, CD-RW, etc., a method of wobbling a groove on an optical disk to record address information as an FM signal, and recording data in error correction block units based on this. There is. In this case, since the address of the error correction block is determined only after data is recorded, it is generally difficult to record data at an arbitrary position without waste.

Further, since the address information of the error correction block and the address information of the sector cannot be taken out without solving the error correction, even if the address is deviated during recording, it cannot be dealt with. Data may be recorded. Furthermore, even when seeking to another track, the address information must be corrected for errors, and the time required to find the target address becomes longer, so that there is a drawback that the data read / write wait time becomes longer. Also, the groove wobble (wobbl)
The address information recorded in the form of e) is degraded during many times of writing.

Further, in an area where data is written, a periodic signal having a sector cycle necessary for controlling the spindle motor is obtained from the optical disk. In an area where data is not written, such a periodic signal is generated. I can't get it. For this reason, after writing the data, finalization processing for recording a dummy signal for generating a periodic signal on a plurality of tracks is required, and extra recording time is required.

As described above, among the conventional rewritable optical disks, in an optical disk in which address information in sector units is recorded as pre-pits, the actual sector caused by fluctuations in the rotational speed of the disk, eccentricity, and the like for each sector. Since it is necessary to provide a buffer area to cope with a change in length or a random shift of the recording position when using the phase change recording method and deterioration of the start and end, an area other than an area for recording the original data is required. Increased format efficiency.

On an optical disk on which address information is recorded by wobbling a groove and data is recorded in units of error correction blocks, it is not only difficult to record data at an arbitrary position without waste, but also to release error correction. Address information cannot be obtained in sector units without
Further, there is a problem that a finalization process for generating a periodic signal for controlling the spindle motor is required, and it takes a long time for recording.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the format efficiency, to record data at an arbitrary position without waste, and to obtain address information in sector units without error correction. It is an object of the present invention to provide a rewritable optical disk and an optical disk device for driving the optical disk.

It is another object of the present invention to provide an optical disk and an optical disk apparatus which can control the rotation by using a signal obtained from the optical disk without requiring any extra finalization processing.

[0013]

According to the present invention, there is provided an optical disk in which data is recorded and reproduced in units of error correction blocks using a light beam. A land track and a groove track, and an emboss pit formed on a boundary between the land track and the groove track for recognizing a position of the error correction block, wherein a groove depth DG of the groove track is Λ / (4n) <DG <λ / (2n) where λ is the wavelength of the light beam, n is the refractive index of the medium through which the light beam propagates, and the depth DP of the embossed pit is DG <DP < An optical disk characterized by being set within a range represented by λ / (2n).

Here, the depth DP of the embossed pit
May be set in a range represented by DG <DP ≦ λ / (2.3n).

Further, according to the present invention, in an optical disc on which data is recorded and reproduced in units of error correction blocks using a light beam, land tracks and groove tracks which are alternately arranged adjacent to each other, and And embossed pits formed on the boundary between the land track and the groove track for recognizing the position of the groove track.
Where 0 <DG ≦ λ / (4n) λ: the wavelength of the light beam n: the refractive index of the medium through which the light beam propagates, the depth DP of the embossed pit is 3λ / (8n) <DP <Λ / (2n) Provided is an optical disk characterized by being set within the range indicated by:

Here, the depth DP of the embossed pit
May be set in a range represented by 3λ / (8n) <DP ≦ λ / (2.3n).

Further, according to the present invention, in an optical disk on which data is recorded and reproduced in units of error correction blocks using a light beam, land tracks and groove tracks which are alternately arranged adjacent to each other, and And embossed pits formed on the boundary between the land track and the groove track for recognizing the position of the groove track.
Where λ / (4n) <DG <λ / (2n) where λ is the wavelength of the light beam, n is the refractive index of the medium through which the light beam propagates, and the depth DP of the embossed pits is 0 <DP <Λ / (6.75n) An optical disk characterized by being set within the range indicated by:

Here, the depth DP of the embossed pit
Is set within the range represented by λ / (8n) ≦ DP <λ / (6.75n) or the range represented by λ / (16n) ≦ DP <λ / (6.75n) May be set.

Further, according to the present invention, in an optical disc on which data is recorded and reproduced in units of error correction blocks using a light beam, land tracks and groove tracks which are alternately arranged, and the error correction block And embossed pits formed on the boundary between the land track and the groove track for recognizing the position of the groove track.
Where 0 <DG ≦ λ / (4n) λ: wavelength of the light beam n: refractive index of a medium through which the light beam propagates, the depth DP of the embossed pit is expressed by 0 <DP <DG. An optical disc characterized by being set within a range set in the optical disc.

Here, the depth DP of the embossed pit
May be set within a range represented by λ / (8n) ≦ DP <DG, or may be set within a range represented by λ / (16n) ≦ DP <DG. .

Further, according to the present invention, in an optical disk on which data is recorded and reproduced in units of error correction blocks composed of a plurality of sectors using a light beam, land tracks and groove tracks arranged alternately adjacent to each other are used. And an emboss pit formed on a boundary between the land track and the groove track for recognizing a position of the error correction block, wherein the emboss pit is an address of a first sector constituting the ECC block. An optical disc characterized by recording information by a PPM recording method is provided.

Further, according to the present invention, there is provided a motor for rotating and driving the optical disk, an optical head for irradiating the optical disk with a light beam, and a photodetector for detecting the reflected light of the light beam from the optical disk, The optical disc is
A land track and a groove track alternately arranged adjacent to each other, and emboss pits formed on a boundary between the land track and the groove track for recognizing a position of the error correction block; When the groove depth DG of the track is λ / (4n) <DG <λ / (2n) λ: wavelength of the light beam n: refractive index of a medium through which the light beam propagates, the depth of the embossed pit DP is set within a range represented by λ / (8n) ≦ DP <λ / (6.75n), and the photodetector is:
There is provided an optical disk device comprising a light receiving surface divided into two by a dividing line parallel to a track tangential direction, and detecting a sum signal from the light receiving surface as a signal from the embossed pit.

The present invention also includes a motor for driving the optical disk to rotate, an optical head for irradiating the optical disk with a light beam, and a photodetector for detecting the reflected light of the light beam from the optical disk, The optical disc is
A land track and a groove track alternately arranged adjacent to each other, and emboss pits formed on a boundary between the land track and the groove track for recognizing a position of the error correction block; When the groove depth DG of the track is λ / (4n) <DG <λ / (2n) λ: wavelength of the light beam n: refractive index of a medium through which the light beam propagates, the depth of the embossed pit DP is set within a range represented by λ / (16n) ≦ DP <λ / (6.75n), and the photodetector is:
There is provided an optical disk device comprising a light receiving surface divided into two by a dividing line parallel to a track tangential direction, and detecting a difference signal from the light receiving surface as a signal from the embossed pit.

Further, according to the present invention, there is provided a motor for rotating and driving an optical disk, an optical head for irradiating the optical disk with a light beam, and a photodetector for detecting the reflected light of the light beam from the optical disk, The optical disc is
A land track and a groove track alternately arranged adjacent to each other, and emboss pits formed on a boundary between the land track and the groove track for recognizing a position of the error correction block; When the groove depth DG of the track is 0 <DG ≦ λ / (4n) λ: the wavelength of the light beam n: the refractive index of the medium through which the light beam propagates, the depth DP of the emboss pit is λ / (8n) ≦ DP <DG, and the photodetector is
There is provided an optical disk device comprising a light receiving surface divided into two by a dividing line parallel to a track tangential direction, and detecting a sum signal from the light receiving surface as a signal from the embossed pit.

The optical disk further includes a motor for driving the optical disk to rotate, an optical head for irradiating the optical disk with a light beam, and a photodetector for detecting the reflected light of the light beam from the optical disk. A land track and a groove track alternately arranged adjacent to each other, and emboss pits formed on a boundary between the land track and the groove track for recognizing a position of the error correction block; When the groove depth DG of the track is 0 <DG ≦ λ / (4n) λ: the wavelength of the light beam n: the refractive index of the medium through which the light beam propagates, the depth DP of the emboss pit is λ / (16n) ≦ DP <DG, and the photodetector is
There is provided an optical disk device comprising a light receiving surface divided into two by a dividing line parallel to a track tangential direction, and detecting a difference signal from the light receiving surface as a signal from the embossed pit.

Further, the depth DP of the embossed pit
May be set within a range obtained by adding mλ / (2n) (m is a positive integer) to the first and third sides of the inequality indicating the range.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. First, an optical disc according to an embodiment of the present invention will be described. 1 shows an enlarged part of the optical disk, FIG. 2 shows a track pattern on the optical disk, and FIG. 3 shows an enlarged part of FIG. FIG.
Indicates a spiral format on the optical disk.

As shown in FIG. 1, the optical disk 10 of this embodiment is formed by forming a recordable / reproducible recording film 12, for example, a phase change film on a disk substrate 11. Land tracks 13 and groove tracks 14 are formed in a spiral shape on the disk substrate 11 as shown in FIGS. Land track 13 and groove track 14
There are two types of arrangement methods, a single spiral format shown in FIG. 4A and a double spiral format shown in FIG. 4B. Single spiral format uses land track 13 on one spiral.
The double spiral format is a method in which land tracks 13 and groove tracks 14 are respectively arranged on two parallel spirals. In both cases, land and groove tracks 14 are arranged along the radial direction of the disk. The grooves are arranged alternately adjacent to each other.
The present invention can be applied to any of these systems.

In this embodiment, as shown in FIGS. 2 and 3, the land track 13 and the groove track 14 are wobbled by a wobble pattern having a constant period. FIGS. 1 and 4 show diagrams without wobbling for simplicity.

As shown in FIGS. 1, 2 and 3,
The groove track 14 is divided on the way, and the divided area is a land portion 15. An emboss pit 16 is formed on the boundary between the land portion 15 and the adjacent land track 13 in the divided area. Here, the emboss pits are formed together with the land / groove tracks by a masking process when forming the disk.

The emboss pits 16 are provided on the boundaries between the land portions 15 separating the groove tracks 14 and the land tracks 13 adjacent either inside or outside in the disk radial direction. Thereby, the recognition information of the ECC block given by the emboss pit 16 is shared by both the land track 19 and the groove track 13 located on both sides thereof.

The emboss pit 16 is for giving information for recognizing the position of an error correction block (hereinafter, referred to as an ECC block) in a land track and a groove track located on both sides thereof. It represents a boundary and is formed with a period substantially equal to the ECC block length. Further, the emboss pit 16 is composed of a set of a plurality of, preferably three or more pits. Each emboss pit may have the same pit pattern as long as it is used only for simply recognizing the position of the ECC block. Although a circular pit is shown in the figure, the shape of the pit is not limited to this, and may be an ellipse, an ellipse, or a combination thereof.

Since the emboss pit 16 may be provided for recognizing the ECC block, the emboss pit 1 can be provided without providing the division area 15 in the groove track 14.
6 may be provided. That is, pits may be formed in the land track 13 in a semicircular form, and these pits may be used as ECC block recognition information.

As described above, by forming the embossed pit 16 indicating the recognition information of the ECC block for each ECC block, the format efficiency can be increased as will be described later in detail.

FIG. 3 shows specific numerical examples of the land tracks 13, groove tracks 14, emboss pits 16 and light beam spots 17a and 17b on the optical disk 10. This is a conventional DVD-RA
This is an example of a rewritable optical disk in which M has been further densified.
The track pitch (center line interval between the land track 13 and the groove track 14) is 0.55 μm, and the width of the emboss pit 16 is 0.35 μm. Further, the wavelength λ of the light beam is 650 nm, and the NA of the objective lens is 0.6.
And the light beam spot diameter is φ0.93 μm.

The signal from the emboss pit 16 is detected, for example, when the light beam spot 17a is tracing on the land track 13 adjacent to the emboss pit. In this case, since the light beam spot 17a traces a part of the groove track 14 adjacent to the land track 13 traced by the light beam spot 17a, the light beam spot 17a is affected by recording marks such as phase change marks formed on the groove track 14. You need to think.

Further, when the light beam spot 17b traces on the groove track 14, it is necessary to consider the effect of the emboss pit 16 when detecting a recording mark formed on the groove track 14.

When address information is recorded in sector units as in a conventional DVD-RAM, as shown in FIG. 5, the positions where embossed pits are provided in the radial direction of the disk are on a straight line (hereinafter, referred to as ""). Will be aligned. "
). Therefore, there is no problem of the influence of signals between adjacent tracks due to the embossed pits, that is, crosstalk.

On the other hand, when embossed pits are provided in units of ECC blocks as in the present invention, these pits are not aligned, so that the influence of the crosstalk as described above is a concern.

FIG. 6 shows the effect of such crosstalk.
This will be described with reference to FIG. Here, the influence of crosstalk due to adjacent emboss pits when the light beam spot traces a land track or a groove track will be described. The disc used in the description has a track pitch (tp) of 0.55 μm and a pit and groove depth of 150 n.
m, the pit width is 0.35 μm.

FIG. 6 is an MTF diagram showing the signal amplitude when the light beam spot 17a traces the land track 13 and the signal amplitude of the crosstalk from the emboss pit. In the figure, the horizontal axis represents the spatial frequency in units of NA / λ, and the vertical axis represents the signal amplitude normalized with the amount of light reflected on the mirror surface as 1.0. In the figure, the solid line and the broken line show the signal amplitude at the time of on-track, and the solid line shows the case where the radial tilt of the disc is zero, and the two kinds of broken lines show the case where the radial tilt of the disc is ± 0.6 deg. It represents. The dotted line indicates the signal amplitude of the crosstalk, and here, the case where the radial tilt of the disk having the largest crosstalk is -0.6 deg. It should be noted that the signal amplitude of the crosstalk is shown to be ten times the actual value.

As is apparent from the figure, the signal amplitude of the crosstalk is large especially in the low frequency band, and the influence of the crosstalk is concerned.

FIG. 7 is an MTF showing the signal amplitude when the light beam spot 17b traces the groove track 14 and the signal amplitude of the crosstalk from the emboss pit.
FIG. The display in the figure is the same as that in FIG. 6, but the signal amplitude of the crosstalk shows the case where the disc radial tilt is 0.6 deg. When the light beam spot 17b traces the groove track 14, the same result is obtained when the radial tilt of the disc is ± 0.6 deg among the signal amplitudes at the time of on-track, so that the broken lines overlap.

In this case, although the frequency characteristics of the crosstalk are different from those of FIG. 6, the signal amplitude of the crosstalk is large especially in the low frequency band, and the influence of the crosstalk is concerned. You can see that there is.

Next, an embodiment of the present invention for reducing the influence of such crosstalk will be described. As a first embodiment, a method for reducing the influence of crosstalk by forming the pit depth of the emboss pit larger than the groove depth will be described.

FIGS. 8 and 9 show the signal amplitude change of the crosstalk when the depth of the emboss pit is made larger than the groove depth when the light beam spot traces the land track and the groove track, respectively.
It is a TF diagram.

FIGS. 8 and 9 show the on-track signal amplitude and the crosstalk signal amplitude under the same conditions as those shown in FIGS. 6 and 7, and the crosstalk signal amplitude is embossed. Pit depth from 150nm
The results are shown as four changes between 180 nm. As is clear from both figures, the effect of crosstalk is reduced by increasing the depth of the emboss pit.

From this result alone, the deeper the embossed pit, the better it is, but in fact, the signal from the embossed pit (Complementary)
Allocated Pit Address (CA
It is desirable to set an upper limit in order to secure the output of the PA) reproduction signal) to a certain value or more.

FIG. 10 is an MTF diagram showing signal amplitude changes of the sum signal (ADD) and the difference signal (SUB) at the time of CAPA reproduction of a DVD-RAM. The CAPA playback signal is
A photodetector having a light receiving surface divided into two by a dividing line parallel to the track tangential direction is detected as a sum signal or a difference signal from the light receiving surface. Here, the track offset amount (t-off) of the emboss pit, that is, the distance from the center of the beam spot that scans the emboss pit to the center of the track of the emboss pit is 0.37 μm. As shown in the figure, of the two CAPA reproduction signals,
Since the difference signal has a higher output, the difference signal is usually used as a CAPA reproduction signal in DVD-RAM.

On the other hand, as shown in FIG. 11, when the track offset amount is reduced to 0.275 nm, the sum signal generally has a higher output, so that the CAPA reproduction signal of the high-density disc is the sum signal. It turns out that it is better to use the signal. Here, the depth of the embossed pit is different between FIG. 10 and FIG. 11, but the general tendency does not change.

Next, the change in the amplitude of the CAPA reproduction signal when the depth of the emboss pit is changed will be described.
12 and 13 show that the track offset amount is 0.2
Emboss pit depth of 150 nm when 75 nm
FIG. 11 is an MTF diagram showing signal amplitude changes of a sum signal and a difference signal when the signal is changed in four ways between １８０180 nm. As is clear from both figures, the output of the sum signal and the difference signal decreases as the depth of the emboss pit increases. Since it is desired to secure a CAPA reproduction signal amplitude of about 0.25 in a low frequency region, the depth of the embossed pit is desirably up to about 175 nm regardless of whether a sum signal or a difference signal is used.

Based on the above considerations, a groove depth (DG) called a so-called deep groove is defined as: λ / (4n) <DG <λ / (2n) λ: wavelength of light source n: medium through which light beam propagates For a disk having a refractive index of, the emboss pit depth (DP) suitable for reducing the effect of crosstalk is represented by a general formula: DG <DP <λ / (2n). Further, it is desirable to satisfy DG <DP ≦ λ / (2.3n) in order to prevent a decrease in the output of the CAPA reproduction signal. In the present embodiment, λ /
(2.3n) corresponds to 175 nm.

On the other hand, in the case of a disk having a shallow groove depth, that is, a disk having a groove depth (DG) of 0 <DG ≦ λ / (4n) λ: wavelength of a light source n: refractive index of a medium through which a light beam propagates When the emboss pit depth (DP) suitable for reducing the influence of crosstalk is expressed by a general formula, 3λ / (8n) <DP <λ / (2n). Further, in order to prevent a decrease in the output of the CAPA reproduction signal, it is preferable that 3λ / (8n) <DP ≦ λ / (2.3n). In the present embodiment, 3λ /
(8n) is 150 nm, λ / (2.3n) is 175 n
m.

The influence of the groove depth and the pit depth is considered to be the same in a period of λ / (2n) from the viewpoint of optical properties. Therefore, the case where mλ / (2n) (m is a positive integer) is added to the first side and the third side of the above inequality is considered to belong to the present invention.

Next, as a second embodiment, a method of reducing the influence of crosstalk by forming the pit depth of the emboss pit smaller than the groove depth will be described.

FIGS. 14 and 15 are MTF lines showing the signal amplitude change of the crosstalk when the depth of the emboss pit is smaller than the groove depth when the light beam spot traces the land track and the groove track, respectively. FIG.

14 and 15, FIG. 6 and FIG.
The signal amplitude during on-track and the signal amplitude of crosstalk are shown under the same conditions as in the case shown in FIG. 2, and the signal amplitude of crosstalk indicates that the depth of the embossed pit is 30 nm.
The results are shown as four different values between ６０60 nm. As is clear from both figures, the effect of crosstalk is reduced by reducing the depth of the emboss pit.

From these results alone, the shallower the embossed pit, the better. However, in practice, the signal from the embossed pit (CAPA playback) is the same as when the depth of the embossed pit is deep. It is desirable to set a lower limit in order to secure the output of the signal) above a certain value.

In the present embodiment, a change in the amplitude of the CAPA reproduction signal when the depth of the emboss pit is changed will be described. FIGS. 16 and 17 are MTF lines showing signal amplitude changes of the sum signal and the difference signal when the emboss pit depth is changed in five ways between 20 nm and 60 nm when the track offset amount is 0.275 nm. FIG.

As shown in FIG. 16, the output of the sum signal decreases as the depth of the emboss pit decreases. Since it is desired to secure about 0.25 in the low frequency band as the output of the CAPA reproduction signal, when using the sum signal, the depth of the embossed pit is desirably up to about 50 nm.

On the other hand, as shown in FIG. 17, for the difference signal, a sufficient signal amplitude can be obtained even if the depth of the emboss pit is about 25 nm. As mentioned above,
Generally, when the track offset amount of the emboss pit is small, it is better to use the sum signal as the CAPA reproduction signal. However, when the depth of the emboss pit is smaller than the groove depth, it is better to use the difference signal. It turns out to be good.

Based on the above considerations, a groove depth (DG) called a so-called deep groove is as follows: λ / (4n) <DG <λ / (2n) λ: wavelength of light source n: medium through which light beam propagates For a disk having a refractive index of, the emboss pit depth (DP) suitable for reducing the effect of crosstalk is represented by a general formula: 0 <DP <λ / (6.75n). Further, in order to prevent a decrease in the output of the CAPA reproduction signal, (when a sum signal is used) λ / (8n) ≦ DP <λ / (6.75n) (when a difference signal is used) λ / (16n) It is preferable that ≦ DP <λ / (6.75n). In the present embodiment, λ /
(6.75n) is 60 nm, λ / (8n) is 50 nm,
λ / (16n) corresponds to 25 nm.

On the other hand, in the case of a disk having a shallow groove depth, that is, a disk having a groove depth (DG) of 0 <DG ≦ λ / (4n) λ: wavelength of a light source n: refractive index of a medium through which a light beam propagates When the emboss pit depth (DP) suitable for reducing the influence of crosstalk is expressed by a general formula, 0 <DP <DG. Further, in order to prevent a decrease in the output of the CAPA reproduction signal, (when using a sum signal) λ / (8n) ≦ DP <DG (when using a difference signal) λ / (16n) ≦ DP <DG It is desirable. In the present embodiment, λ / (8
n) corresponds to 50 nm, and λ / (16n) corresponds to 25 nm.

The influence of the groove depth and the pit depth is considered to be the same in a period of λ / (2n) from the viewpoint of optical properties. Therefore, the case where mλ / (2n) (m is a positive integer) is added to the first side and the third side of the above inequality is considered to belong to the present invention.

Next, as a third embodiment, a method for reducing the influence of crosstalk by limiting the frequency band of the CAPA reproduction signal will be described. Specifically, as a modulation method for recording and reproducing data, it is conceivable to adopt a method that does not use a low-frequency region (for example, 0.4 NA / λ or less) with much crosstalk. For example, a DVD-RAM (single-sided 2.6 GB) employs a (2,10) RLL code in 8/16 modulation, and a frequency band used thereby is 0.175 to 0.867 NA.
/ Λ. Therefore, when emboss pits are provided in ECC block units as in the present invention, it is desirable to use another modulation code. For example, a bit density of 0.28
When the (1,7) RLL modulation code is adopted at μm / bit, the frequency band used thereby becomes 0.357 to 0.357.
1.43 NA / λ, and the effect of crosstalk is considerably reduced.

As another method, when address information is recorded in an embossed pit portion (details will be described later),
it Position Modulation (PP
M) It is possible to adopt a recording method. This is because, according to the PPM method, since all the emboss pits are composed of pits having a short pit length, it is considered that crosstalk hardly occurs.

As described above, the emboss pit in the present invention may be provided only for recognizing the ECC block. In such a case, a single frequency signal may be recorded. At this time, it is preferable to select a frequency that does not belong to a low frequency region where the influence of crosstalk is large as described above (for example, 0.4 NA / λ or more).

As described above, the optical disk 10 is replaced with the current DVD.
-Even if the track pitch is narrowed to achieve a higher density than that of the RAM and the light beam spot size is further narrowed to cope with this, the recording marks on the adjacent land / groove tracks 13 and 14 are affected. The signal from the embossed pit 16 can be detected with a sufficient SNR, and the signal from the recording mark on the groove track 14 adjacent to the position where the embossed pit 16 is formed is not affected by the embossed pit 16 It is possible to reliably detect.

Next, an optical disk drive for recording and reproducing data by driving the optical disk 10 described above with reference to FIGS. 18 and 19 will be described. In FIG. 18, the optical disk 10 is rotated by a spindle motor 21 driven by a motor driver 20, and the optical disk 10
Recording / reproducing on / from the optical disk 10 is performed by the optical head 22 provided to face the optical disk 10. The optical head 22 is
Although not limited to this, a laser diode (LD) 23 as a light source, a collimator lens 24 for converting a light beam emitted from the laser diode 23 into parallel light, 1
Beam splitter 25 for separating reflected light from zero
And an objective lens 26 for condensing the light beam that has passed through the beam splitter 25 and irradiating the light beam onto the optical disk 10 as a minute light beam spot, and reflecting light reflected by the optical disk 10 and guided by the beam splitter 25. It comprises a condenser lens 27 for condensing, a photodetector 28 for detecting the condensed reflected light, and a lens actuator 29 for moving the objective lens 26 in the optical axis direction (focus direction) and the tracking direction.

The photodetector 28 has a plurality of detection areas, for example, four detection areas.
A multi-segment detector divided into two regions is used. The plurality of output signals output from the photodetector 28 are input to the analog operation circuit 34. The analog operation circuit 33
A reproduction signal corresponding to data recorded on the optical disk 10, a focus error signal and a tracking error signal for focus servo and tracking servo, and a speed control signal for controlling a rotation speed of the spindle motor 21 are generated. The focus servo is a control for making the focus of the objective lens 26 coincide with the recording surface on the optical disk 10, and the tracking servo is a control for the optical disk 1.
This is control for causing the light beam irradiated on the zero to follow the track.

The focus error signal and the tracking error signal are input to the servo circuit 30, and the objective lens 26 is controlled in the focus direction and the tracking direction by the lens actuator 29 under the control of the servo circuit 30. Further, the servo circuit 30 controls the motor driver 20 according to a speed control signal generated based on a later-described periodic signal obtained from the optical disc 10.

Next, an outline of the recording operation and the reproducing operation will be described. (Recording Operation) At the time of recording, a recording data sequence Din, which is data to be recorded, is processed by a recording data processing unit 31, and then input to an LD driver 32, and the LD driver 3
2, the laser diode 23 is intensity-modulated. The light beam whose intensity has been modulated is collimator lens 24,
By being irradiated onto the optical disk 10 via the beam splitter 25 and the objective lens 26, the optical disk 10
Is recorded as a recording mark, for example, a phase change mark from crystalline to amorphous or from amorphous to crystalline.

Here, at the time of recording, the reflected light from the optical disk 10 enters the photodetector 28 via the objective lens 26, the beam splitter 25 and the condenser lens 27.
The output of the photodetector 28 is input to an analog arithmetic circuit 33, and the signal (CAPA reproduction signal) corresponding to the embossed pits 16 on the optical disk 10 and the amplitude corresponding to the wobble pattern of the land track and the groove track on the optical disk 10. Is generated.

The timing generation circuit 34 generates recognition information of the ECC block corresponding to the emboss pit 16 according to the CAPA reproduction signal, and further generates a speed control signal according to the periodic signal. ECC block recognition information is
Generation of an ECC block in the recording data processing unit 31;
Further, it is used for generating sector address information. The details of this processing will be described later in detail. The speed control signal is input to the servo circuit 30, and the servo circuit 30 controls the spindle motor 21 to a predetermined rotation speed via the motor driver 20 based on the speed control signal.

At the time of recording, the analog arithmetic circuit 33 further generates a focus error signal and a tracking error signal, and the lens actuator 29 is controlled by the servo circuit 30 based on these signals. Tracking servo is performed.

(Reproduction Operation) At the time of reproduction, a light beam of a constant intensity emitted from the laser diode 23 is irradiated with the collimator lens 24, the beam splitter 25 and the objective lens 2.
The light is irradiated onto the optical disk 10 through 6. Optical disk 1
The reflected light from 0 is reflected by the objective lens 26 and the beam splitter 2
The light enters the photodetector 28 via 5 and the condenser lens 27. The output of the photodetector 28 is supplied to an analog arithmetic circuit 33.
And a change in reflectance depending on the presence or absence of a recording mark on the recording film 12 is output as a reproduction signal.

During the reproduction, the analog arithmetic circuit 33 generates a periodic signal corresponding to the wobble pattern on the optical disk 10, a focus error signal and a tracking error signal. A timing control circuit generates a speed control signal in accordance with the periodic signal, and the servo circuit 30 controls the spindle motor 21 to a predetermined rotation speed via the motor driver 20 based on the speed control signal. Further, the lens actuator 29 is controlled by the servo circuit 30 based on the focus error signal and the tracking error signal, so that focus servo and tracking servo are performed.

The reproduction signal corresponding to the recording mark output from the analog operation circuit 33 is converted into binary data by the binarization circuit 35 and then input to the timing generation circuit 34. The timing generation circuit 34 detects a synchronization pattern in the reproduction signal from the binary data, specifically, detects the position and pattern of the synchronization pattern. Since the reproduction signal includes a bit error generated due to a medium defect of the optical disc 10 or the influence of noise, the synchronization signal cannot be detected at a position where the synchronization pattern should be detected in the timing generation circuit 34 or differs from the original synchronization pattern. A synchronization pattern may be erroneously detected at a position. The timing generation circuit 34 considers these effects,
It has a function of correctly detecting the position of the synchronization pattern, and in addition to the detection position signal of the synchronization pattern, combines a synchronization pattern detection signal indicating which of the synchronization pattern sequences SY0 to SY7 described below is present. The boundary of each of the demodulated symbol, the recording block, and the recording sector after the modulation is determined using the above.

The output of the binarization circuit 35 is input to the reproduction data processing section 36. The reproduction data processing unit 36
As shown in the figure, the recording data processing unit 31 includes a demodulation circuit 361, a memory 362, a memory controller 363 for controlling the memory, and an error correction decoding processing unit 366. And outputs a reproduced data sequence Dout.

Next, the recording data processing section 31 will be described in detail. FIG. 20 shows a processing procedure of the recording data processing unit 31. First, the recording data sequence Din is input from, for example, a host system (not shown) (step S10).
1).

Next, a data frame is generated from the recording data sequence Din input in step S101 (step S102). Data frame generation step S102
Then, after dividing the recording data series Din into data sectors in units of 2048 bytes, 178
Generate a data frame of × 12 bytes.

FIG. 21 shows the structure of a data frame.
As shown in the figure, the data frame is composed of 2064 bytes arranged in a 12-row array with 172 bytes as one row. The first line is 4-byte data identification data (data ID) and a 2-byte ID error detection code (IED) for detecting an error occurring in the data ID.
, 6 bytes of spare bytes (RSV), and 160 bytes of main data D0 to D159. Main data is an element of a data sector. The second to eleventh lines are 172 bytes of main data D160 to D33, respectively.
1, D332 to D503, ..., D1708 to D187
The last 12th row is composed of 168-byte main data D1880 to D2047 and a 4-byte error detection code (EDC) for detecting an error that has occurred in a data frame.

Hereinafter, the data ID will be described in more detail. As shown in FIG. 22A, the data IDs are sequentially numbered with the least significant bit being b0 and the most significant bit being b31. The meaning of each bit of the data field information consisting of the most significant 1 byte is shown in FIG.
And is set as follows.

Bit b31 (sector format type): set to "1" to indicate a zoned format. Bit b30 (tracking method): “0” indicating pit tracking in the embossed portion in the lead-in zone
, And in other regions, it is set to “1” indicating groove tracking.

Bit b29 (reflectance of recording film):
It is set to “1”, indicating that the reflectance is 40% or less. Bit b28 (spare): set to "0"

Bits b27 and b26 (zone type): set to "00" in the data zone, "01" in the lead-in zone, and "10" in the lead-out zone. Bit b25 (data type): data in the data sector is read-only data (read-only data)
Is set to "0" at the time of, and "1" at the time of rewritable data.

Bit b24 (layer number): Set to “0”, indicating that only one recording film can be accessed from one incident surface. On the other hand, the data field number composed of the lower 3 bytes of bits b23 to b0 indicates the sector number in the embossed portion in the lead-in zone, the defect management area and the spare zone in binary, and the data zone is initialized and re-initialized. The subsequent data field number is shown, and the sector number is shown in binary notation in the defect management area and the spare zone in the lead-out zone.

After the data frame is generated in step S102, a scramble process is performed (step S103).
In this scrambling process, the main data Dk (k = 0 to 2047) in the data frame is replaced with Dk ′ (k = 0 to 2047) scrambled by the following equation.

Dk ′ = Dk XOR Sk, k = 0-2
[047] Here, XOR represents exclusive OR. Sk is a random data sequence for scrambling, for example, an M sequence, and is generated by the following procedure. That is, a 15-bit shift register is prepared, and the most significant bit and the output of the fifth bit from the most significant bit are exclusive-ORed,
The result is connected to the input of the least significant bit to form a so-called feedback shift register. As the scramble data, the lower 8-bit output of the feedback shift register is used. Each time the scrambled data is taken out, the feedback shift register is shifted upward eight times to take out the next scrambled data.

The scramble processing can be performed by taking the exclusive OR of the scramble data generated by the above procedure and the main data for each bit. In this case, the generated scramble data sequence can be switched by changing the initial value of the feedback shift register. The switching of the initial value is performed according to the content of the data ID in the data field.

The ECC block is generated by performing error correction coding on the data frame (referred to as a scrambled frame) after the scramble processing in step S103 (step S104).

FIG. 23 shows the structure of the ECC block.
The ECC block includes a scrambled frame in each row 17.
By arranging 192 rows as 2 bytes, and adding 16 bytes as outer code parity PO to each 172 columns, 208 rows are obtained, and adding 10 bytes as inner code parity PI to each of these rows, 182 bytes in each row The ECC block is composed of 208 rows consisting of Each byte is as follows when i is the number of rows and j is the number of columns and Bi, j is set.

Bi, j for i = 0 to 191 and j = 0 to 171: bytes from the scrambled frame. Bi for i = 192 to 207, Bi for j = 0 to 171.
j: byte of outer code parity Bi for i = 0 to 207, j = 172 to 181
j: Byte of inner code parity To further explain the above-described ECC block generation procedure, 16 scrambled frames of 12 rows are stacked, and a set of 16 scrambled frames is used as an error correction coding data unit. A check parity is added by performing correction coding to generate an ECC block. Here, the error correction code is a Reed-Solomon code 2
Use multiply sign.

That is, first, 192 rows of data of 16 stacked scrambled frames are encoded (outer encoding), and an outer code parity P of 16 bytes is obtained.
O is generated. The outer code is (208, 192, 17)
RS code. The same outer coding is repeated for all the columns (172 columns) of the 16 scrambled frames stacked. Next, 172 bytes of data in each row of the 16 scrambled frames of the stack are encoded (inner encoding) to generate an inner code parity PI of 10 bytes. The inner code is (182, 172, 1
1) It is an RS code. Similar inner coding is repeated for all the rows of the 16 scrambled frames stacked, that is, 208 rows including the outer code parity PO.

A recording frame is generated by interleaving one of the 16 outer code parities PO in every 12 rows of the ECC block shown in FIG. 23 generated in step S104. Specifically, the recording frame is generated by rearranging the bytes Bi, j of the ECC block as Bm, n with respect to the following equation.

M = i + int [i / 12] and n = j, i ≦ 191 m = 13 (i−191) −1 and n = j, i ≧ 192 where int [x] is an integer less than or equal to x Represent.

As a result, 37856 bytes of the ECC block are 16 bytes of 2366 bytes as shown in FIG.
Are rearranged into recording frames. Each recording frame is
Each row forms an array of 13 rows of 182 bytes.

The data of the recording frame generated in step S105 is recorded on the optical disc 10
Then, data conversion in accordance with the signal transmission characteristics of the optical head 22, that is, modulation processing is performed (step S106).
In order to reduce the recording density (linear density) on the optical disk 10 as much as possible, it is desirable that the maximum frequency of the recording signal is low, and from the viewpoint of signal transmission, the recording signal desirably has a low frequency component. In consideration of these two requirements, step S1
As a modulation method in 06, a method in which frequency components are generally concentrated in the middle band is used. As the modulation method, in the present embodiment, for example, a continuous length of “0” is “2” for 8-bit data,
RLL in which the continuous length of "1" is limited to "10" respectively
8/16 modulation is used to convert to a 16-bit codeword consisting of (2,10) codes. This 16-bit codeword is NRZ-I converted into channel bits. The channel bit is an element that expresses binary “1” and “0” after modulation by pits or marks on the optical disc 10.

A data field for recording on the optical disk 10 is generated from the recording frame after the modulation processing obtained in step S106. When reproducing data recorded on the optical disk 10, the original data cannot be reconstructed unless boundaries between recording frames can be determined. Therefore,
In step S107, as shown in FIG. 11, a 32-bit synchronization pattern is added to the beginning of 1456 channel bits of each recording frame after the modulation processing to generate a 1488-bit-length synchronization frame, thereby forming a data field. . This data field is composed of 13 rows, each row consisting of two synchronization frames.
The 456 channel bits represent the first and second 91 eight-bit bytes of each one row of the recording frame.
Each row of the data field represents each row of the recording frame.

As the synchronization pattern, it is desirable to select a pattern that can be easily detected from the recording data sequence and that is not erroneously detected. In FIG. 25, eight types of synchronizing pattern sequences SY0 to SY7 are prepared as the synchronizing pattern. These synchronization pattern sequences SY0
~ SY7, one synchronization pattern is selected according to the position of the recording frame in the data field after the modulation processing.

Finally, the recording format of the ECC block is generated from the data field generated in step S107. According to the generated recording format, LD
The intensity of the light beam emitted from the laser diode 23 is modulated by the driver 32, thereby recording on the optical disk 10 as described above. The recording format of the ECC block will be described later in detail.

Next, the reproduction data processing section 36 shown in FIG. 19 will be described. First, the demodulation circuit 361 includes the binarization circuit 3
After dividing the binary data from 5 into 16-bit data on the basis of the boundary of the demodulated symbol, the divided data is converted to 8-bit data by performing a process reverse to the modulation process, that is, performing 16/8 demodulation, and reproducing data. Generate In this case, the relative position of the synchronous frame with respect to the head of the modulated recording frame is determined by determining whether the synchronous pattern of the synchronous frame in the continuously obtained reproduction data is one of the synchronous pattern sequences SY0 to SY7. judge.

Next, the demodulation circuit 361 extracts data identification data (data ID) from the reproduced data on the basis of the beginning of the recording frame, and then extracts the data I
D is checked for errors by an ID error detection code (IED), and in order to further protect the reliability, the memory 3 is sequentially read from the beginning of the recording frame and the data ID.
The reproduction data is written to the block 62.

The memory controller 363 has one EC.
When the reproduction data of the 16 recording frames forming the C block is written into the memory 362, the memory 362
, And transfers the inner code parity to the error correction decoding unit 364. The error correction decoding processing unit 364 receives this, performs error correction of the inner code, and when there is an error exceeding the error correction capability of the inner code, determines that the error cannot be corrected and sets the error flag. Generate. The data after error correction and the error flag are written to the memory 362.

In error correction decoding processing section 364, EC
When error correction of all inner codes in the C block is completed,
Next, the memory controller 363 reads the outer code parity from the memory and transfers the same to the error correction decoding processing unit 364 in the same manner, and the error correction decoding processing unit 364 corrects the error of the outer code. Further, the memory controller 363 reads an error flag generated at the time of error correction of the inner code in parallel with the reading of the outer code parity. Error correction decoding processing unit 3
At 64, erasure correction is performed using this error flag. As in the case of the error correction of the inner code, the data after the error correction and the error flag are written into the memory.

Further, the memory controller 363 reads out the error-corrected data in the memory 362 and performs descrambling processing for restoring the scrambled data when generating the recording data. The descrambling process is performed by taking the exclusive OR of the same random data sequence as in the scrambled process and the data after error correction. The data after descrambled processing read from the memory 362 in this manner is the reproduction data series Do.
ut is output.

FIG. 26 shows a recording format of an ECC block on the optical disc 10 according to the present embodiment. In this figure, the contents of each field of the ECC block are indicated by the upper alphabet, and the byte length is indicated by the lower numeral. As shown in the figure, at the beginning of each sector constituting the ECC block, address fields AD0 to AD1 are provided.
5 (only AD0 is shown in the figure).
The sector address fields AD0 to AD15 are ECC
An area for giving address information of each sector constituting a block, and includes a VFO field, an AM field, and a PID.
Field, an IED field, and a PA field.

Here, the address information recorded in each sector address field is information that has not been subjected to error correction processing, and can be detected without error correction. Therefore, by using this address information, even if the optical head goes off the track, the damage can be minimized and the seek time can be reduced.

Generally, a disk is shipped after performing an initialization operation. Initialization is the work of writing data such as the physical address of each sector using emboss bits provided in units of ECC blocks as a mark. DVD-RAM performs an initial inspection (certify) to detect an initial defect during initialization. And defect management. The above-mentioned address fields AD0 to AD15 are recorded on the disk by an initialization operation. The initialization may be performed by the user using an optical disk device having the function. For example, in the optical disk device shown in FIG. 18, the initialization information including the physical address information is processed by the recording data processing unit, and the light beam intensity-modulated by the laser diode 23 via the LD driver 32 is emitted.
The optical disk is irradiated with the light beam via the collimator lens 24, the beam splitter 25, and the objective lens 26, thereby performing an initialization operation.

When actual recording data is recorded on the initialized disk, a correct address is determined based on the start address information ADO of the first sector constituting each ECC block, and a gap from Gap (to be described later) to immediately before Buffer is determined. Rewrite all areas up to Guard. Therefore, once the head address information AD0 is written by the initialization work, it is not rewritten unless the initialization work is performed again thereafter. On the other hand, the subsequent address information AD1 to AD15 are rewritten each time the ECC block is rewritten. Therefore, the head address information AD0 is important information for determining an address, and usually, a plurality of, preferably two to four, are provided continuously as shown in FIG. As described above, by providing a plurality of pieces of address information, it is possible to increase the address reading accuracy. On the other hand, since AD1 to AD15 can be rewritten every time, it is sufficient to provide 1, 2 ADs.

The head address information AD0 may be formed by the above-mentioned emboss bits. In such a disk, data can be recorded from any position without performing initialization work.

At the time of data recording, following the first sector address field AD0, a Gap field and a Gua field
An rd1 field is arranged, and after the Guard1 field, a VFO field, a PS field, a DATA field, a DATA field of the first sector, and a PA field are sequentially recorded as phase change marks. After this,
Following the second sector address field AD1 consisting of a VFO field, an AM field, a PID field, an ID field, and a PA field, a PS field, a DATA field of the second sector, and a PA field are sequentially recorded as phase change marks.

Hereinafter, similarly, sector address field A
Dn (n = 1, 2,..., 15) and the subsequent PS field, DATA field, and PA field have n = 1
It is recorded five times as a phase change mark.

16th sector address field AD15
Followed by the PS field, the 16th sector DAT
After the A field and the PA field, a Guard2 field and a Buffer field are formed.
One ECC block is completed.

Hereinafter, the contents of each field will be described. VFO field The VFO field is a field for providing synchronization to the variable frequency oscillator of the phase locked loop of the read channel bit. The VFO field in the ECC block address field (first sector address field) AD0, and the Gap field after AD0 , Guard1 field, each has a length of 36 bytes, and the VFO field in the second to sixteenth sector address fields has a length of 12 bytes.

AM (Address Mark) Field The address mark is a field for providing byte synchronization to the optical disk device for the next PID field, and is composed of a mark pattern that cannot be generated by 8/16 modulation and has a 3-byte size. Have a length.

PID (physical identification data) field This is 4-byte data including a spare area, a PID number, a sector type, a layer number, and a sector number.

IED (ID error detection code) field An IED field for detecting an error occurring in the data ID, and is 2-byte data.

PA (postamble) field Data for completing 8/16 modulation of the last byte of the preceding field (IED field or data field), and has a length of 1 byte (16 channel bit length). Have.

Gap (gap) field A field for obtaining a waiting time until the light beam output from the laser diode 23 as a light source rises to a predetermined power, and is 10 + J / 16 bytes, that is, (1)
60 + J) have a channel bit length. Number J is 0 ≦
It changes randomly between J ≦ 15. Variations in the length of the Gap field are compensated for by the length of the Buffer field described later.

Guard 1 field A field arranged next to the Gap field.
It has a length of (20 + K) bytes and repeats a predetermined 16 channel bit pattern (20 + K) times. The number K is
"0" to "0" to shift the position of the phase change mark formed in the field following the Guard1 field to the field following the Guard2 field.
It changes randomly between “7”. The first 20 bytes of the Guard1 field are for protecting the beginning of the subsequent VFO field from signal degradation after overwriting many times, and the contents are ignored when reading data.

Pre-sync code (PS) field This is data for causing the optical disc device to perform byte synchronization for the next data field, and is a unique channel bit pattern having a length of 3 bytes (48 channel bits). Consists of

DATA field This is an area where the data of the data field described above is recorded as a phase change mark, and has a length of 2418 bytes.

Guard 2 field This is a field provided before the last Buffer field of the ECC block, has a length of (55-K) bytes, and has the same 16-channel bit pattern as the Guard 2 field. Repeat 55-K) times. Number K
Is set so that the total length of the Guard1 field and the Guard2 field is 71 bytes. The last 20 bytes of the Guard2 field are for protecting the end of the DATA field after overwriting many times from signal degradation, and the remaining (5 bytes)
(5-K-20) bytes are for absorbing the fluctuation of the actual length of the data written on the optical disk 10, and the contents thereof are ignored when reading the data.

Buffer field This buffer field is provided at the end of the ECC block, and changes in the actual sector length caused by fluctuations in the rotation speed of the optical disk 10 during data writing, track eccentricity, and the like, and further, the recording position during phase change recording. Is a region for absorbing the random shift and the deterioration of the start and end of the image. In this example, the region is 140-J / 16.
It has a length of bytes. The Buffer field is provided for each sector in the current DVD-RAM, but is provided for each ECC block, that is, every 16 sectors in the present embodiment. By doing so, according to the present embodiment, the format efficiency can be increased by the reduced amount of the buffer area as compared with the current DVD-RAM.

Hereinafter, the effect of improving the format efficiency according to the present invention will be described with reference to specific numerical examples. In the present embodiment, the ECC block is a 46-byte ECC block address AD0, (10 + J / 1) as shown in FIG.
6) Gap field of byte, Guard1 field of (20 + K) bytes, VFO field of 36 bytes, PS field of 3 bytes, DA of 2418 bytes
2 consisting of a TA field and a 1-byte PA field
488 bytes of first sector data and 12 bytes of VF
O field, 3 byte PM field, 2418 byte DATA field, 4 byte PID field, 2 byte ID field, 1 byte PA field, 3 byte PS field, 2418 byte D field
ATA field, 2444 bytes each consisting of 1 byte PA field, 36660 bytes in total, 2nd to 16th
It is composed of sector data, a Guard2 field of (55-K) bytes, and a Buffer field of (25-J / 16 bytes), and the ECC block length is 383.
It is 89 bytes.

Accordingly, according to the present embodiment, the current DVD
-The ECC block length is 38389 bytes / 43152 bytes = 91% as compared with the RAM. That is, the capacity required to record the same data is the current DVD-RA
M is 91%, and the format efficiency is expected to improve by 9%.

In the above embodiment, the emboss pit 16 is used as recognition information indicating the boundary (start end) of the ECC block, and recognizes the ECC block in which data is written by counting the number of the boundaries of the ECC block. be able to.

[0129]

As described above, according to the present invention,
Even if the track pitch is narrowed to increase the recording density of the optical disc and the light beam spot size is further narrowed to cope with this, the embossing is not affected by the recording marks on the adjacent land / groove tracks. A signal from a pit can be detected with a sufficient SNR, and a signal from a recording mark on a land / groove track adjacent to the position where the emboss pit is formed is reliably detected without being affected by the emboss pit. It becomes possible.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing a part of an optical disc according to an embodiment of the present invention.

FIG. 2 is a plan view showing a track pattern on an optical disc according to one embodiment of the present invention.

FIG. 3 is an enlarged plan view showing a part of the optical disc according to the embodiment of the present invention.

FIG. 4 is a plan view showing a spiral format on an optical disc according to an embodiment of the present invention.

FIG. 5 is a plan view showing a track pattern on an optical disk in which address information is recorded in sector units as in a conventional DVD-RAM.

FIG. 6 is an MTF diagram showing a signal amplitude when a light beam spot traces a land track and a signal amplitude of crosstalk from an emboss pit.

FIG. 7 is an MTF diagram showing a signal amplitude when a light beam spot traces a groove track and a signal amplitude of crosstalk from an emboss pit.

FIG. 8 is a graph showing a change in signal amplitude of crosstalk when the depth of an emboss pit is made larger than the groove depth when the light beam spot traces a land track.
TF diagram.

FIG. 9 is an MTF diagram showing a signal amplitude change of crosstalk when the depth of an emboss pit is made larger than the groove depth when a light beam spot traces a groove track.

FIG. 10 is an MTF diagram showing signal amplitude changes of a sum signal (ADD) and a difference signal (SUB) at the time of CAPA reproduction of a DVD-RAM.

FIG. 11 is an MTF diagram showing a signal amplitude change of a sum signal (ADD) and a difference signal (SUB) at the time of CAPA reproduction of a DVD-RAM with high density.

FIG. 12: Emboss pit depth of 150 nm to 180
FIG. 4 is an MTF diagram showing a signal amplitude change of a sum signal when the signal is changed in four ways between nm.

FIG. 13: Emboss pit depth of 150 nm to 180
MTF diagram showing the signal amplitude change of the difference signal when changed in four ways between nm

FIG. 14 is an MTF diagram showing a signal amplitude change of crosstalk when the depth of an emboss pit is made smaller than the groove depth when a light beam spot traces a land track.

FIG. 15 is an MTF diagram showing a signal amplitude change of crosstalk when the depth of an emboss pit is smaller than the groove depth when the light beam spot traces a groove track.

FIG. 16 shows an emboss pit depth of 20 nm to 60 nm.
FIG. 8 is an MTF diagram showing a signal amplitude change of a sum signal when the sum signal is changed in five ways.

FIG. 17: Emboss pit depth of 20 nm to 60 nm
FIG. 6 is an MTF diagram showing a signal amplitude change of a difference signal when the signal is changed in five ways between the two.

FIG. 18 is a block diagram showing a configuration of an optical disk device according to one embodiment of the present invention.

FIG. 19 is a block diagram showing a reproduction data processing unit of the optical disc device according to one embodiment of the present invention.

FIG. 20 is a flowchart showing a processing procedure of a recording data processing unit in the optical disc device according to one embodiment of the present invention.

FIG. 21 is a diagram showing the structure of a data frame.

FIG. 22 is a view showing the structure of a data ID and its sector information.

FIG. 23 is a diagram showing a logical structure of an ECC block.

FIG. 24 is a diagram showing the structure of a recording frame.

FIG. 25 is a diagram showing the structure of a data field.

FIG. 26 is a view showing a recording format of an ECC block on an optical disc according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Optical disk 11 ... Disk substrate 12 ... Recording film 13 ... Land track 14 ... Groove track 15 ... Land part of the division area | region of a groove track 16 ... Emboss pit 17a, 17b ... Light beam spot 20 ... Motor driver 21 ... Spindle motor 22 ... Optical head 23 ... Laser diode 24 ... Collimator lens 25 ... Beam splitter 26 ... Objective lens 27 ... Condenser lens 28 ... Photodetector 30 ... Servo circuit 31 ... Recording data processing unit 32 ... LD driver 33 ... Analog arithmetic circuit 34 ... Timing Extraction circuit 35 Binarization circuit 36 Reproduction data processing unit

Claims (17)

[Claims] 1. An optical disk in which data is recorded and reproduced in units of error correction blocks using a light beam, wherein land tracks and groove tracks arranged alternately and adjacently and positions of the error correction blocks are recognized. And embossed pits formed on the boundary between the land track and the groove track, and the groove depth DG of the groove track is λ / (4n) <DG <λ / (2n) λ: When the wavelength n of the light beam is the refractive index of a medium through which the light beam propagates, the depth DP of the embossed pit is set within a range represented by DG <DP <λ / (2n). An optical disk characterized by the above-mentioned. 2. The optical disk according to claim 1, wherein a depth DP of the emboss pit is set within a range represented by DG <DP ≦ λ / (2.3n). 3. An optical disk in which data is recorded and reproduced in units of error correction blocks using a light beam, wherein land tracks and groove tracks arranged alternately and adjacently, and positions of the error correction blocks are recognized. And embossed pits formed on the boundary between the land track and the groove track, wherein the groove depth DG of the groove track is 0 <DG ≦ λ / (4n) λ: When the wavelength n is the refractive index of the medium through which the light beam propagates, the depth DP of the embossed pit is set within a range represented by 3λ / (8n) <DP <λ / (2n). An optical disk characterized by the above-mentioned. 4. The optical disk according to claim 3, wherein a depth DP of the embossed pit is set in a range represented by 3λ / (8n) <DP ≦ λ / (2.3n). . 5. An optical disk in which data is recorded and reproduced in units of error correction blocks using a light beam, wherein land tracks and groove tracks arranged alternately and adjacently and positions of the error correction blocks are recognized. And embossed pits formed on the boundary between the land track and the groove track, and the groove depth DG of the groove track is λ / (4n) <DG <λ / (2n) λ: When the wavelength n of the light beam is the refractive index of the medium through which the light beam propagates, the depth DP of the embossed pit is set within a range represented by 0 <DP <λ / (6.75n). An optical disc characterized by becoming. 6. The optical disk according to claim 5, wherein a depth DP of the emboss pit is set in a range represented by λ / (8n) ≦ DP <λ / (6.75n). . 7. The optical disk according to claim 5, wherein the depth DP of the embossed pit is set in a range represented by λ / (16n) ≦ DP <λ / (6.75n). 8. In an optical disk on which data is recorded and reproduced in units of error correction blocks using a light beam, land tracks and groove tracks arranged alternately and adjacently, and positions of the error correction blocks are recognized. And embossed pits formed on the boundary between the land track and the groove track, wherein the groove depth DG of the groove track is 0 <DG ≦ λ / (4n) λ: An optical disc characterized in that the depth DP of the embossed pits is set within a range represented by 0 <DP <DG, where wavelength n is a refractive index of a medium through which the light beam propagates. 9. The optical disk according to claim 5, wherein a depth DP of the emboss pit is set in a range represented by λ / (8n) ≦ DP <DG. 10. The optical disk according to claim 5, wherein a depth DP of the emboss pit is set in a range represented by λ / (16n) ≦ DP <DG. 11. The depth DP of the embossed pit is defined by mλ / m on the first and third sides of the inequality indicating the range.
The optical disk according to any one of claims 1 to 10, wherein (2n) (m is a positive integer) is set within a range. 12. An optical disk in which data is recorded and reproduced in units of error correction blocks composed of a plurality of sectors using a light beam, wherein land tracks and groove tracks arranged alternately and adjacently; Emboss pits formed on the boundary between the land track and the groove track for recognizing the position of a block, wherein the emboss pit records the address information of the first sector constituting the ECC block by PPM. An optical disc characterized by being recorded by a system. 13. A motor for rotating and driving an optical disc, an optical head for irradiating a light beam on the optical disc, and a photodetector for detecting reflected light of the light beam from the optical disc, wherein the optical disc comprises: Land tracks and groove tracks arranged alternately and adjacently, and embossed pits formed on boundaries between the land tracks and the groove tracks for recognizing positions of the error correction blocks; When the groove depth DG of the track is λ / (4n) <DG <λ / (2n) λ: wavelength of the light beam n: refractive index of the medium through which the light beam propagates, the depth of the embossed pit DP is set in a range represented by λ / (8n) ≦ DP <λ / (6.75n), and the photodetector is flat in a track tangential direction. An optical disc device comprising: a light receiving surface divided into two by a dividing line; and detecting a sum signal from the light receiving surface as a signal from the embossed pit. 14. An optical disk, comprising: a motor for rotating and driving an optical disk; an optical head for irradiating the optical disk with a light beam; and a photodetector for detecting reflected light of the light beam from the optical disk. Land tracks and groove tracks arranged alternately and adjacently, and embossed pits formed on boundaries between the land tracks and the groove tracks for recognizing positions of the error correction blocks; When the groove depth DG of the track is λ / (4n) <DG <λ / (2n) λ: wavelength of the light beam n: refractive index of the medium through which the light beam propagates, the depth of the embossed pit DP is set within a range represented by λ / (16n) ≦ DP <λ / (6.75n), and the photodetector is arranged in a track tangential direction. An optical disc device comprising: a light receiving surface divided into two by parallel dividing lines; and detecting a difference signal from the light receiving surface as a signal from the embossed pit. 15. A motor for rotating and driving an optical disk, an optical head for irradiating the optical disk with a light beam, and a photodetector for detecting reflected light of the light beam from the optical disk, Land tracks and groove tracks arranged alternately and adjacently, and embossed pits formed on boundaries between the land tracks and the groove tracks for recognizing positions of the error correction blocks; When the groove depth DG of the track is 0 <DG ≦ λ / (4n) λ: the wavelength of the light beam n: the refractive index of the medium through which the light beam propagates, the depth DP of the emboss pit is λ / (8n) ≦ DP <DG The photodetector is divided into two parts by a dividing line parallel to the track tangent direction. Optical disc apparatus characterized by being provided with a light receiving surface was, and detects the sum signal from the light receiving surface as a signal from the emboss pit. 16. A motor for rotating an optical disk, an optical head for irradiating the optical disk with a light beam, and a photodetector for detecting reflected light of the light beam from the optical disk; Land tracks and groove tracks arranged alternately and adjacently, and embossed pits formed on boundaries between the land tracks and the groove tracks for recognizing positions of the error correction blocks; When the groove depth DG of the track is 0 <DG ≦ λ / (4n) λ: the wavelength of the light beam n: the refractive index of the medium through which the light beam propagates, the depth DP of the emboss pit is λ / (16n) ≦ DP <DG. The photodetector is divided into two parts by a dividing line parallel to the track tangential direction. Optical disc and wherein the is a light receiving surface was, and detects a difference signal from the light receiving surface as a signal from the emboss pit. 17. The depth DP of the embossed pit is defined as mλ / m on the first and third sides of the inequality indicating the range.
17. The optical disk device according to claim 13, wherein (2n) (m is a positive integer) is set within a range.