JPH08287474A - Data recording medium and recording and reproducing device using the data recording medium - Google Patents

Abstract

PURPOSE: To enable quick access to a multilayered disk. CONSTITUTION: An inner guard area 2, program area 3 and outer guard area 4 are formed in each layer of this multilayered disk in such a manner that the position of these areas in the radial direction is same at every layer. In the uppermost layer (recording layer 7a), recording is carried out in the direction from the inner circumference to the outer circumference, while in the next layer (recording layer 7b), recording is carried out in the direction from the outer circumference to the inner circumference. As above described, recording directions are alternately changed. The end position of recording in the uppermost first layer (recording layer 7a) and the starting position of recording in the second layer (recording layer 7b) are same in the redial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording medium suitable for recording, for example, a digital signal and a recording / reproducing apparatus used for the data recording medium.

[0002]

2. Description of the Related Art A multi-layer disc is known in which a plurality of recording layers are formed on a disc and the layers are selectively read by controlling the focus of an optical pickup. For example, US Pat. No. 5,263,011
Japanese Unexamined Patent Publication No. 2003-242242 discloses such a multilayer disc and a recording / reproducing apparatus using the disc.

A double-sided disc has been proposed in which a single recording layer is formed on both sides of the disc and each layer is selectively read.

[0004]

However, no data recording and / or reproducing apparatus compatible with the above-mentioned two types of discs, the single-sided multi-layer disc and the double-sided single-layer disc, has been disclosed. Furthermore, data recording and / or reproduction of a disc having recording layers formed on both sides and at least one side having multiple recording layers is not disclosed.

Further, the disclosure of the multi-layer disc described in the above-mentioned document is not considered in practical use, but is in a research stage. That is, nothing is disclosed about writing and reading actual data. In particular, video data using compressed code and / or
Alternatively, it does not consider recording and reproducing audio data.

For example, in a conventional CD (compact disc), recording tracks are formed from the inner circumference of the disc toward the outer circumference. But for multi-layer discs,
There is no disclosed example of how to form a recording track. Therefore, although the technique used for the conventional single-layer disc can be used in some cases, there are many problems to be newly examined.

Therefore, an object of the present invention is to provide a data recording medium and a recording / reproducing apparatus using the data recording medium.

[0008]

According to a first aspect of the present invention, there is provided a disc-shaped data recording medium, wherein identification information corresponding to the number of recording layers on both sides is written in a predetermined area of the recording layer. It is a data recording medium characterized by the above.

According to a second aspect of the present invention, there is provided a disc-shaped data recording medium having recording layers on both sides, wherein the recording layer has multiple recording layers on at least one side, and the recording layer is provided in a predetermined area of the recording layer. The data recording medium is characterized in that the identification information corresponding to the reproduction order is written.

According to a third aspect of the invention, data recording means for recording data on a disk-shaped data recording medium and identification information corresponding to the number of recording layers on both sides are provided in a predetermined area of the recording layer. The recording device comprises identification information generating means for supplying identification information to the data recording means so as to be written.

According to a fourth aspect of the present invention, data reproducing means for reproducing data from a disk-shaped data recording medium and the number of recording layers on both sides correspond to the number and the data is written in a predetermined area of the recording layer. And the identification information extracting means for extracting the identification information from the output of the reproducing means.

Further, in the invention described in claim 5, data recording means for recording data on a disk-shaped data recording medium, and identification information corresponding to the number of recording layers on both sides are provided in a predetermined area of the recording layer. The data recording means comprises identification information generating means for supplying identification information to the data recording means, data reproducing means for reproducing data from the data recording medium, and identification information extracting means for extracting the identification information from the output of the reproducing means. It is a recording / reproducing device.

[0013]

The data recording medium of the present invention can discriminate between two types of discs, a single-sided multi-layer disc and a double-sided single-layer disc, and can perform data recording and / or reproduction corresponding to them.

Further, a disc having recording layers formed on both sides and at least one side having a multi-layer recording layer can be identified, and data recording and / or reproduction corresponding thereto can be performed.

Furthermore, it is possible to identify the reproduction order of a disc having recording layers formed on both sides and at least one side having a multilayer recording layer, and it is possible to perform data reproduction corresponding to the reproduction order.

[0016]

An embodiment of the present invention will be described below. One embodiment of the present invention is a double-sided multilayer disc having recording layers on both sides and a plurality of recording layers provided on at least one side in the disc thickness direction. In the following description, in the case of multiple layers, the recording layer closest to the pickup side is referred to as the uppermost recording layer. FIG. 1A is a schematic view of the disc 1 viewed from above in order to explain the area of the disc according to the present invention. Reference numeral 2 denotes an inner guard area (hereinafter referred to as IGA), 3 denotes a program area, and 4 denotes an outer guard area (hereinafter referred to as OGA). In the case of the uppermost recording layer L0 of the multilayer, IGA is the lead-in area and OGA is the lead-out area. In the next layer L1, OGA is the lead-in area and IG.
A is the lead-out area.

FIG. 1B is an example of a cross-sectional view of a double-sided multilayer disc according to the present invention. The disc 1 is composed of a base 6, a recording layer 7 and a protective layer 8, and a recording layer 7a or 7 which is desired to be recorded or reproduced using the objective lens 5.
The laser light is focused so as to focus on b. This double-sided multilayer disc is composed of a protective layer 8a, a recording layer 7a, a protective layer 8b and a recording layer 7b on one side, and a protective layer 8c and a recording layer 7c on the other side, with the base 6 as the center.
And has an objective lens 5'for recording or reproducing on the recording layer 7c on the other side.

Next, the structure of each of the layers will be described with reference to FIG. First, in the present invention, the case where a spiral recording track is formed from the inner circumference to the outer circumference, and conversely,
A spiral recording track may be formed from the outer circumference to the inner circumference. Further, among a plurality of layers, there are alternating layers for recording from the inner circumference to the outer circumference and from the outer circumference to the inner circumference. Further, as an example, the even-numbered layers L0, L2,
... are the odd-numbered layers L1, L3, from the inner circumference to the outer circumference.
... is recorded from the outer circumference to the inner circumference. Here, the even and odd numbers indicate the reference numbers given to the layer L for explanation,
The uppermost layer (recording layer 7a in FIG. 1B) is L0, which is the even-numbered layer although it is the first layer.

That is, FIG. 2A shows spiral recording tracks Te of even-numbered layers, and as shown by arrows,
Recording from the inner circumference to the outer circumference. On the other hand, FIG.
As indicated by an arrow in B, the recording tracks To of the odd-numbered layers are recorded spirally from the outer circumference to the inner circumference. In this case, the uppermost layer is always the 0th layer L0.
Recording in the direction from the inner circumference to the outer circumference.

When these are divided based on the direction of the spiral, it means that a recording track is formed of a forward spiral recording track Te and a reverse spiral recording track To depending on the layer. Furthermore, the even-numbered layers L0, L2, ...
Indicates a forward spiral recording track Te, and odd-numbered layers L1, L3, ... Reverse spiral recording track To.
For recording, the layers of the forward spiral recording track Te and the layers of the reverse spiral recording track To are alternately stacked.
The uppermost layer L0 is always the forward spiral recording track Te (in the same direction as a normal CD). this is,
This is because when the disc size is the same as that of a normal CD, it is possible to identify the type of the disc that is erroneously loaded.

Returning to FIG. 1 again, the program areas on the disc are arranged so that their ends are aligned with each other. That is, the signal end portion of the even-numbered layer and the signal start portion of the odd-numbered layer are positioned substantially on the same radius of the disc. For example, the signal end portion of the even-numbered layer and the signal start portion of the odd-numbered layer are in close proximity to each other. Since it is sufficient that the radii are substantially the same, the end portion and the start portion do not have to be close to each other. More specifically, the total amount of data to be recorded on the disc is calculated, and it folds back at half the total amount of data, that is, moves to the next lower layer, and all data ends at the same radius as the inner circumference of the upper layer. To do so. By doing so, the repeated reproduction is facilitated and the access speed is further increased when moving to a lower layer. Therefore, as shown in FIG. 1, when the program area is viewed from above, the layers in each layer are the same.

Next, IGA and OGA will be described. As shown in FIG. 1, the IGA on the inner peripheral side of each layer is unified. Also, the OGA of each layer is unified to the one having the largest recording area (program area) in the recording medium.
This is because when the read layer is changed by performing a focus jump near the inner circumference or near the outer circumference, IGA and OGA can be identified in any layer.

In the CD, the unrecordable area of the innermost data and the end of the data are detected in the lead-in / lead-out area, but this method is possible because the CD is a single layer. is there. Since the disc according to the present invention is multi-layered, unlike the case of a CD, even if the data ends in one layer, the data may still be recorded in another layer at that position. .

In this embodiment, even if the data recorded in a certain layer ends, if the data is recorded in a position in the vicinity of another layer, empty data (for example, all "0") is written. "Data) etc. are recorded. A track in which empty data is recorded is called an empty track. If empty data is not recorded, there is a risk that the sector header information cannot be found when the focus jump is performed from the recorded layer to change the read layer. If the sector header information cannot be obtained, there arises a problem that it becomes difficult to control the pickup and the servo.

Next, TOC (Table Of Contents) will be described with reference to FIG. FIG. 3 shows allocation of recording tracks on the disk, and allocation of each layer is shown in the disk cross section. In the figure, 2 indicates IGA, 3 indicates a program area, and 4 indicates OGA. The arrow indicates the moving direction of the pickup.

First, the positions for recording the IGA or OGA TOC are unified in each of the even-numbered layer and the odd-numbered layer. That is, the TOC of the layer L0 (TOC
0) and the TOC of layer L2 (TOC2) are in the same area. This reduces the time required for IGA.

The top layer is the TOC of all layers.
Record (TOC00). As a result, the disc state can be identified only by the IGA of the first layer L0 of all the layers. Furthermore, the TO of the other layer is added to the first layer L0.
If C, for example TOC00, is recorded, the TOC0 for the own layer will be used to facilitate the distinction from other layers.
Is recorded at a fixed location, the location closest to the program area. By doing so, the time from the IGA to the start of the program is shortened.

In TOC00, important data defining the disc is written. For example, if both conventional single-layer discs and multi-layer discs are allowed as standards, it is necessary to identify whether this disc is a single-layer disc, a multi-layer disc, a single-sided disc, or a double-sided disc. The ID is written in TOC00. In this embodiment, an ID for identifying a double-sided multi-layer disc having two layers on one side and a single layer on the other side as shown in FIG. 1B.
Is written in TOC00.

Further, by linking with TOC0 to TOCn of each layer, it is possible to determine which layer TOC is accessed first and then TOC00 in response to an access request. Furthermore, by recording the outermost radius of the program area of each layer in TOC00,
It is possible to prevent the pickup from trying to read any further perimeter area. Therefore, for example, when discs of different sizes are defined by the standard, overrun (pickup jumping out of the program area) when using a disc of a small size can be prevented.

The data recorded on the disc 1 is
It has a sector structure. This sector will be described with reference to FIGS. 4 and 5. First, FIG. 4 schematically discloses the sector structure of the first layer L0. In the example shown in FIG. 4, in order to facilitate understanding,
Although a conformal velocity (CAV) type disc is shown,
In practice, a constant velocity (CLV) type disk is used because of its recording density.

The data of each layer is a sector (00 to 255).
Is recorded as a unit. At this time, considering that it is one program, it is easy to assign serial numbers to the sector addresses for a plurality of layers. For example, sector addresses (256 to 511) are used in the second layer (not shown), and sector addresses (512 to 767) are used in the third layer.
To use. In addition, the layer number must be written to facilitate layer selection.

Therefore, as shown in FIG. 5A, the layer number is recorded in the subcode SC of each sector. In addition to the layer number, preferably from the inner circumference to the outer circumference (or vice versa),
Subcode SC for the direction of cutting such as reverse spiral
Described in.

As the layer information included in the subcode SC, it is possible to have the total number of recording layers on the disc in addition to the layer number. Such an example is shown in FIG. In FIG. 6, the total number of layers of 3 bits (b5 to b3) and 3 bits (b2 to b3) in the layer field of 1 byte.
It has a layer number field of 0).

The definition of the total number of layers is shown in FIG. here,
1, 2, 3 and 4 are defined as the number of recording surfaces. For example, if both conventional single-layer discs and multi-layer discs are allowed as standards, this field is used to identify whether this disc is a single-layer disc or a multi-layer disc. As an example of this multi-layer disc, one side has up to two layers, the side on which TOC00 is recorded is the A side, and the other side is the B side. In the case of a three-layer disc, the A-side has two layers and the B-side has one layer.

The definition of the layer number is shown in FIG. Here, A
Layer numbers L0 and L1 for surface, layer numbers L0 and L for surface B
Although only one is defined, the usage of this field is similar to that illustrated in Figures 5A and 5B. By using this layer number and the total number of layers, it is possible to determine what kind of disc is used.

Besides being described as a subcode, as shown in FIG. 5B, a combination of the layer number and the sector address may be used as the sector address in the multilayer disc. That is, the layer number is added as the upper bits of the sector address. At this time, the layer number of the uppermost layer is always 0. Therefore, the sector address of the uppermost layer is (0000-0255). For the other layers, the layer number order and the physical order of the layers are matched. Make sure that the layer numbers are not skipped or the order is changed. This is to facilitate the transition between layers.

Further, another example of the sector header information such as the sector address will be described. The header information includes a track number, a sector address, a copyright code, an application code, etc. in addition to the layer number. The track number is a 16-bit code and has a value (0 to 65).
533) is defined as the value of the track number in the program area of the disc, 65534 is defined as the OGA track number, and 65535 is defined as the IGA track number.

Explaining the sector address, it has a length of 24 bits, and in the following description, $ represents a hexadecimal number. Also, the sector address is
It is a 24-bit two's complement code. In the forward spiral layers L0, L2, ..., Sector addresses increase from the inner side to the outer side of the disk, and in the reverse spiral layers L1, L3 ,. To do. In the forward spiral layer, if the innermost circumference starts to be recorded from $ 000000, in the reverse spiral layer, the sector address is recorded at, for example, $ 800,000 at the innermost circumference. At the position of the same radius of the disk, the sector address SAd0 of the layer L0,
The sector address SAd1 of the layer L1 has the following relationship.

SAd1 = SAd0 XOR $ 7FFFFF In this way, if the radius is the same, the sector address of any layer in the forward spiral direction or the reverse spiral direction can be converted by a simple calculation. Exclusive OR (XO for $ 7FFFFF
This is because R) should be taken.

Particularly in the case of a CLV disc, the number of sectors per track differs depending on the radius. Therefore, when the servo circuit accesses a specific sector, it is effective to use the current position (radius information) of the pickup to determine the number of track jumps. Further, the radius information can be obtained from the sector address by a method such as table reference. In this case, if sector addresses are assigned without consideration in the forward spiral direction and the reverse spiral direction, it is necessary to prepare separate tables for the forward spiral direction and the reverse spiral direction. Further, if the sector address at the outermost periphery is not determined by the standard or the like, the reference table cannot be used for calculation, so that it is necessary to calculate or measure the number of sectors per track.

In this example, as described above, the sector addresses of both layers in the forward spiral direction and the reverse spiral direction are assigned with sector numbers so that they can be converted by a simple calculation. Can also be easily converted to radius information. As a result, the amount of required tables can be reduced and high-speed access can be achieved.

FIG. 9 shows the layout of the disc when the addresses are defined as described above. I of layer L0
The sector address of the last sector of the GA (inner guard area) is set to (-1). The track numbers of all sectors of the IGA are set to 65535. The application code of all sectors in the IGA is set to 0.

The number of sectors in all program areas of the disc is made equal. Unused tracks in the program area are coded as empty tracks. The innermost (first) sector of the program area of layer L0 is set to 0 (that is, $ 000000). The innermost (last) sector address of the program area of layer L1 is $ 7F
FFFF. The relationship between the two is as described above, that is, ($ 7FFFFF = $ 00000 X
OR $ 7FFFFF).

FIG. 9 shows an example of a two-layer disc, which is the layer L0.
The program area of 3 has 3 tracks, and the program area of the layer L1 has 2 tracks. For example, tracks 0, 1, 2, 3 contain user data and track 4
Is an empty truck. The track number of the first track of the layer L1 is a value obtained by adding 1 to the maximum track number of the layer L0.

The first sector address of the OGA (outer guard area) of layer L0 is made equal to the last sector address of the program area plus one. The track numbers of all the sectors of OGA are set to 65534. The application code of all sectors in the OGA is set to 0. In the case of a single-layer disc, the layout of the layer L0 can be applied.

FIG. 10 shows the position of the TOC on the disc in the case of a two-layer disc. Each layer contains 3 copies of the TOC. The TOC is located in the IGA of each layer and consists of the first TOC and the additional TOC. The TOC is recorded as one or more consecutive sectors. At layer L0, the first sector address of the TOC is -3072, 2048, -1.
024. In layer L1, the first sector address of the TOC is (-1XOR $ 7FFFFF), (-1
025 XOR $ 7FFFFF), (-2049 X
OR $ 7FFFFF). In the case of a single-layer disc, the TOC position of the layer L0 may be applied.

The data layout of the first TOC sector is shown in FIG. Each field will be described below. First, the “system ID” includes “HDCD” encoded according to ISO 646.

The "system version number" is the version number of the high density CD system description used for the disc. The first 2 bytes contain the main version number encoded according to ISO 646 and the last 2 bytes contain the secondary version number encoded according to ISO 646. For example, the main version number is "0
1 "and the number of secondary versions is" 00 ".

The "TOC sector number" is 2 bytes in which the number of sectors in the TOC is encoded. "TOC sector number"
Encodes the number of the corresponding sector in the entire TOC. "0" is always recorded in the first TOC sector. A "disk entry" contains several parameters that indicate the characteristics of the disk. The layout of the fields of the disk entry is shown in FIG.

The "disk size" of the disk entry is 1 byte in which the value of the outer diameter [mm] of the disk is encoded. All reservation bytes are $ 00. "Number of layers"
Is one byte that encodes the number of data recording layers of the disc. The "track number" is 2 bytes that encodes the total number of tracks on the disc.

The "logical track number offset" is used as an offset value when converting a physical track number into a logical track number. The physical track number is reset to "0" at the beginning of each disc,
By using a "logical track number offset", one track number space can be created across multiple disks.

The "disc application ID" contains the disc application code. If the disc contains one application code and zero or more free tracks, the disc application ID is equal to the track application code, otherwise the application ID is $ FF.

The "volume ID" is 16 bytes of ISO 646 and includes the disc ID. A groove of a disc having the same volume ID is called a volume set. The number of disks in the volume set is encoded as 2 bytes of the volume set size. The sequence number of the disc in the volume set is encoded as 2 bytes of "volume sequence number".

The address number of the sector containing the disc information is encoded as 24 bits of the "disc information sector". The disc information sector is a code having a two's complement. If the disc information is not available for the disc, the value of the disc information sector is set to -1. The byte offset within the Disc User Data field is encoded as a 2-byte "Disc Information Offset". If the disc information is not available for the disc, the disc information offset value is set to $ FFFF.

In FIG. 11, "layer 0 entry"
Contains information about the top layer (L0), and the "Layer 1 entry" contains information about L1.
Both structures are exactly the same.

FIG. 13 shows the layout of the "layer entry". The 16 bytes of the layer entry contains the parameters of the layer where the TOC is located. The layer number is 1 byte indicating the layer number. "First address" represents the sector address of the first sector of the program area of the layer. The "first address" is the value of the smallest sector address in the corresponding layer. "Last address" represents the sector address of the last sector of the program area of the layer.
The “last address” is the value of the largest sector address in the corresponding layer.

"First track number offset" (2 bytes) represents the value of the first track number in the program area of the layer. “Track number” represents the number of tracks in the program area of the layer.

One byte of "layer type" represents the type of the layer. When the value is 0, it is type I, when it is 1, it is type II, and when it is 2, it is type III. $ 3 ... $ FF is a reservation (usable in the future). One byte of "layer class" represents the class of the layer. A layer class value of 0 indicates read-only. $ 1 ... $ FF is a reservation. The reserved field has a value of $ 00.

The other fields in FIG. 11 will be further described. The "issuer entry" is 64 bytes that contains information about the issuer of the disc. "Manufacturer entry"
Is 32 bytes containing the information of the disc manufacturer. The reservation field is set to $ 00.

A "track entry" contains data for one track on the disc. Track entry 0 contains the data for the first track on the disc. All bytes in unused track entries are $ 0
It is set to 0. The layout of the track entry N is shown in FIG.

The 24 bits (code with 2's complement) of the "track start address" indicates the sector address of the first sector of the track. The first sector in one track is the sector with the smallest sector address in the track. The 24 bits (code with 2's complement) of the "track end address" indicate the sector address of the last sector of the track. The last sector in one track is the sector having the largest sector address in one track.

The "track copyright code" is 1 byte. If the copyright code is the same for all sectors of the track, the track copyright code is made equal to the copyright code of the sector in the track, otherwise the track copyright code is 255.

"Track application code" is 1
It is a byte. If the track is a single application track, the track application code is equated to a non-empty application code. If the track is an application track in which sectors having a plurality of application codes are mixed, the track application code is set to 255. When an empty track is described by the track entry, the track application code is 254.

The "track information sector" is a 24-bit two-complement code. This represents the application of the sector containing the track information. If the track information cannot use the track, the value is set to -1.

FIG. 15 shows the layout of the additional TOC sector. The value of the byte position in FIG. 15 represents the start position of the field in the user data field of the sector. The byte position 0 is the first byte in the user data field of the sector. Each field of the layout of the additional TOC sector is the same as the definition of each field of the layout of the first TOC sector shown in FIG.
The description is omitted. Information about the format of the disc is written in the first TOC or the like.

Next, another example of the identification information for identifying how many recording layers are provided on both sides of the disc of the present invention will be described with reference to FIG. For example, one side of the disc is the A side and the other side is the B side, and the number of recording layers on the A side is N1, B.
If the number of recording layers on each side is N2, layer configuration identification information corresponding to the number of layers on each side can be defined as shown in FIG. 16, and this layer configuration identification information can be written in a predetermined area on the disc. The number of recording layers can be defined in the range of 0 to M (predetermined upper limit value).

Therefore, it is possible to distinguish between a multi-layer disc having a plurality of recording layers provided in the thickness direction of the disc and a double-sided disc having a single recording layer provided on both sides of the disc. It is possible to identify the layer structure of the double-sided multi-layer disc as shown in FIG. 1B, in which at least one side has a multi-layer recording layer.

Further, using the layer structure identification information, for example, a double-sided single-layer disc having a standard recording data rate for recording a standard television signal such as NTSC by data compression by an image compression technique such as MPEG and an HDTV signal or the like. Wideband signal M
The recording mode is identified by associating each layer structure with a mode in which recording is performed at a different recording rate so that a double-sided dual-layer disc having a wideband recording data rate that is compressed by image compression technology such as PEG is recorded. You can also do it.

Next, the reproduction order identification information corresponding to the reproduction order of the disc having the recording layers formed on both sides and at least one side having the multilayer recording layer can be written in a predetermined area on the disc. According to the reproduction order identification information, after each layer on the A side is sequentially reproduced, each layer on the B side may be sequentially reproduced, or each layer on the A side and the B side may be alternately reproduced. As described above, according to the reproduction order identification information, the data reproduction corresponding to the reproduction order can be performed.

Number of recording layers N1 on side A and number N2 of recording layers on side B
And the total of four layers are four layers, the combination of the reproduction order of each layer is, for example, 4! There are 24 ways and can be expressed with 5 bits. If 8 bits are assigned to the reproduction order identification information, when the total of at least the recording layer number N1 on the A side and the recording layer number N2 on the B side is 5 layers, the reproduction order (5! , That is, 120 ways) can be defined. In addition, the playback order when each layer is played back twice or more can be defined.

The layer structure identification information and the reproduction order identification information are written in, for example, the TOC00 area described above.
The data structure of the recording layer and the recording / reproduction thereof are the same as described above, and the explanation about the multi-layer disc is mainly there. However, even in the case of a single-layer disc, the explanation about one layer of the multi-layer disc is directly applied. .

Recording / recording on a double-sided multi-layer disc as described above
FIG. 17 shows the configuration for reproduction. That is, in FIG.
In the example of FIG.
The A side of 1 is read, and the pickup 11b
The side B of the optical disc 11 is read. As shown in the figure, the rotation of the optical disk 11 is controlled by a spindle motor.

Next, an apparatus for recording / reproducing a multi-layer disc according to the present invention will be described. In the multi-layer disc of the present invention, the type of data does not matter. However, for the sake of explanation, for example, MPEG (Moving
FIG. 18 shows a variable rate compatible data (encoding) decoding apparatus as an example of an apparatus used when recording and reproducing a digitalized moving image according to the Pictures image coding Experts Group) standard.

In FIG. 18, the data recorded on the optical disk 11 is the pickups 12a and 12a.
It is adapted to be reproduced by b. The pickups 12a and 12b irradiate the optical disc 11 with laser light and reproduce the data recorded on the optical disc 11 from the reflected light. The signals reproduced by the pickups 12a and 12b are sent to the demodulation circuit 13.
The demodulation circuit 13 includes pickups 12a and 12b.
The reproduced signal output by the demodulator is demodulated and output to the sector detection circuit 14.

The sector detection circuit 14 detects the sector data recorded for each sector from the supplied data and supplies it to the layer separation circuit 29. The layer separation circuit 29 has a T
From the sector data of OC00, the layer configuration identification information LONo,
The reproduction order identification information PBSNo, the sector address SAd and the layer number LNo are separated. The layer configuration identification information LONo is supplied from the layer separation circuit 29 to the layer configuration determination circuit 31 and determines the number of recording layers on the A side and the B side. Then, the reproduction order identification information PBSNo is transferred from the layer separation circuit 29 to the reproduction order determination circuit 3
2 and determines the reproduction order of the recording layers on the A side and the B side. The layer configuration determination result and the reproduction order determination result are the demodulation circuit 1
3 and the tracking servo circuit 27, and a pickup and a pickup output for recording or reproducing data are selected.

The sector address SAd is supplied to the ring buffer control circuit 16 and the sector detection circuit 14 outputs data to the ECC circuit 15 at the subsequent stage in the sector synchronization state. Further, when the sector detection circuit 14 cannot detect the address or the detected addresses are not consecutive, for example, the sector number abnormal signal is sent to the track jump determination circuit 28 via the ring buffer control circuit 16. Output. Also, the layer separation circuit 29
Cannot detect layer number discontinuity,
If the detected layer numbers are not the same, for example, a layer number abnormality signal is output to the track jump determination circuit 28 via the ring buffer control circuit 16.

The ECC circuit 15 detects an error in the data supplied from the sector detection circuit 14 and corrects the error using the redundant bit added to the data, and a track buffer ring buffer memory (FIFO) 17 is provided. Output to. Further, the ECC circuit 15 outputs an error occurrence signal to the track jump determination circuit 28 when the data error cannot be corrected.

The ring buffer control circuit 16 controls writing and reading of the ring buffer memory 17, and monitors a code request signal for requesting data output from the multiplexed data separation circuit 18.

The track jump determination circuit 28 monitors the output of the ring buffer control circuit 16, outputs a track jump signal to the tracking servo circuit 17 when a track jump is required, and the pickups 12a and 12a.
The reproduction position of the optical disc 11 of b is track-jumped. Further, the track jump determination circuit 28 detects the sector number abnormal signal from the sector detection circuit 14, the layer number abnormal signal from the layer separation circuit 29, or the error occurrence signal from the ECC circuit 15, and detects the track jump signal from the tracking servo circuit. 27, and the playback positions of the pickups 12a and 12b are track-jumped.

The data output from the ring buffer memory 17 is supplied to the multiplexed data separation circuit 18. The header demultiplexing circuit 19 of the multiplexed data demultiplexing circuit 18 demultiplexes the pack header and the packet header from the data supplied from the ring buffer memory 17 and supplies the demultiplexed circuit control circuit 21 with the time-division multiplexed data. It is supplied to the input terminal G of the switching circuit 20. Output terminals (switched terminals) H1 and H2 of the switching circuit 20 are connected to input terminals of a video code buffer 23 and an audio code buffer 25, respectively. Further, the output of the video code buffer 23 is connected to the input of the video decoder 24, and the output of the audio code buffer 25 is connected to the input of the audio decoder 26.

The code request signal generated by the video decoder 24 is input to the video code buffer 23, and the code request signal generated by the video code buffer 23 is input to the multiplexed data separation circuit 18. Here, the video data decoded by the video decoder 24 is based on the above-described MPEG standard, and includes an intra-frame coded picture (usually called I picture), an interframe predictive code picture (usually called P picture), and an interframe bidirectional predictive code. Picture (usually called B picture)
The images obtained by the three different encoding methods described above form a predetermined group (referred to as GOP).

Similarly, the code request signal generated by the audio decoder 26 is the audio code buffer 25.
The code request signal generated by the audio code buffer 25 is input to the multiplexed data separation circuit 18. The audio data decoded by the audio decoder 26 is also based on the MPEG standard, or is digital audio data compression-encoded by ATRAC (trademark) proposed by the present applicant, or uncompressed audio data.

Next, the operation of each section of the above data decoding apparatus will be described. The pickups 12a and 12b irradiate the optical disc 11 with a laser beam and reproduce the data recorded on the optical disc 11 from the reflected light. The reproduced signals output by the pickups 12a and 12b are input to the demodulation circuit 13 and demodulated. The data demodulated by the demodulation circuit 13 passes through the sector detection circuit 14 to E
It is input to the CC circuit 15, and an error is detected and corrected. In the sector detection circuit 14, the sector number (address assigned to the sector of the optical disk 11)
Is not normally detected, a sector number abnormality signal is output to the track jump determination circuit 28. ECC
The circuit 15 outputs an error occurrence signal to the track jump determination circuit 28 when uncorrectable data is generated. The error-corrected data is supplied from the ECC circuit 15 to the ring buffer memory 17 and stored therein.

The output (sector data) of the sector detection circuit 14 is supplied to the layer separation circuit 29, and the layer configuration identification information L
It is separated into ONo, reproduction order identification information PBSNo, layer number LNo, and sector address SAd. Both the layer number LNo and the sector address SAd are supplied to the ring buffer control circuit 16. It should be noted that if the layer number (layer number recorded in the sector of the optical disk 11) is not normally detected by the layer separation circuit 29, a layer number abnormality signal is output to the track jump determination circuit 28. The ring buffer control circuit 16 reads the layer number LNo and the sector address SAd from the layer separation circuit 19 and designates a write address (write pointer (WP)) on the ring buffer memory 17 corresponding to the address.

When the optical disk 11 is reproduced by the data decoding device for the first time, information as to whether the optical disk 11 is a single layer or a plurality of layers, and in that case, how many layers, , Important for servo circuits. Therefore, when the optical disc 11 is reproduced for the first time, the number of recording layers on the disc recorded in the subcode is given from the layer separation circuit 19 to the drive control circuit and the tracking servo circuit 27 (not shown). More stable reproduction can be performed.

Further, the ring buffer control circuit 16 specifies the read address (read pointer (RP)) of the data written in the ring buffer memory 17, based on the code request signal from the multiplexed data separation circuit 18 in the subsequent stage. Then, the data is read from the read pointer (RP) and the read data is supplied to the multiplexed data separation circuit 18.

The header separation circuit 19 of the multiplexed data separation circuit 18 separates the pack header and the packet header from the data supplied from the ring buffer memory 17 and supplies them to the separation circuit control circuit 21. Separation circuit control circuit 21
According to the stream id information of the packet header supplied from the header demultiplexing circuit 19, the input terminal G and the output terminals (switched terminals) H1 and H2 of the switching circuit 20 are sequentially connected to correct the time division multiplexed data. Separate and supply to the corresponding code buffer.

The video code buffer 23 issues a code request to the multiplexed data separation circuit 18 depending on the remaining amount of the internal code buffer. Then, the received data is stored. It also receives a code request from the video decoder 24 and outputs internal data. The video decoder 24 reproduces a video signal from the supplied data and outputs it from the output terminal 33.

The audio code buffer 25 uses the remaining amount of the internal code buffer to determine whether the multiplexed data separation circuit 18
Issue a code request to. Then, the received data is stored. It also receives a code request from the audio decoder 26 and outputs internal data. The audio decoder 26 reproduces an audio signal from the supplied data and outputs it from the output terminal 34.

In this way, the video decoder 24 requests data from the video code buffer 23, and the video code buffer 23 sends a request to the multiplexed data separation circuit 18,
The multiplexed data separation circuit 18 is the ring buffer control circuit 1
Make a request to 6. At this time, data flows from the ring buffer memory 17 this time in the opposite direction to the request.

By the way, for example, when the data processing relating to a simple screen continues and the data consumption amount of the video decoder 24 per unit time decreases, the reading from the ring buffer memory 17 also decreases. In this case, the amount of data stored in the ring buffer memory 17 increases and there is a risk of overflow. Therefore, the track jump determination circuit 18 calculates (detects) the amount of data currently stored in the ring buffer memory 17 by the write pointer (WP) and the read pointer (RP), and the data is preset to a predetermined value. When the reference value is exceeded, it is determined that the ring buffer memory 17 may overflow, and a track jump command is output to the tracking servo circuit 27.

Further, the track jump determination circuit 28 is
When the sector number abnormal signal from the sector detection circuit 14 or the error occurrence signal from the ECC circuit 15 is detected,
The amount of data remaining in the ring buffer memory 17 is obtained from the write pointer (WP) and the read pointer (RP), and the disk 1 is determined from the current track position.
While 1 rotates once (while waiting for one rotation of the disk 11), the amount of data required to guarantee the reading from the ring buffer memory 17 to the multiplexed data separation circuit 18 is obtained.

When the amount of remaining data in the ring buffer memory 17 is large, underflow does not occur in the ring buffer memory 17 even if data is read from the ring buffer memory 17 at the highest transfer rate. Determines that error recovery is possible by replaying the error occurrence position with the pickups 12a and 12b, and the tracking servo circuit 2
The track jump command is output to 7.

When the track jump determination circuit 28 outputs a track jump command, the tracking servo circuit 27 causes the reproduction positions of the pickups 12a and 12b to jump to a position on the inner circumference of one track. Then, in the ring buffer control circuit 16, until the reproduction position reaches the position before the optical disk 11 makes one revolution again and jumps, that is, the sector detection circuit 1
Writing of new data to the ring buffer memory 17 is prohibited until the sector number obtained from No. 4 becomes the sector number at the time of track jump, and the data already stored in the ring buffer memory 17 is multiplexed if necessary. The data is transferred to the encoded data separation circuit 18.

After the track jump, even if the sector number obtained from the sector detection circuit 14 matches the sector number at the time of the track jump, the amount of data stored in the ring buffer memory 17 exceeds the predetermined reference value. In this case, that is, when the ring buffer memory 17 may overflow, the writing of data to the ring buffer memory 17 is not restarted and the track jump is performed again.

When the reproduction of the first layer is completed, the sector address SAd is set to a predetermined address, for example (255).
Reach Here, when the reproduction order determination result instructing the reproduction of the second layer on the A side is obtained, the ring buffer control circuit 16 supplies the inversion signal R to the inversion circuit 30.
The inverting circuit 30 inverts the tracking direction moving from the inner circumference to the outer circumference of the pickup 12 and supplies a signal for moving from the outer circumference to the inner circumference to the tracking servo circuit 27. The tracking servo circuit 27 reverses the moving direction of the pickup and, at the same time, adjusts the focal length of the pickup to the second layer as in the objective lens 5'shown in FIG. 1B.

When the tracking is completed, the sector detection circuit 14 outputs the sector data of the second layer, and the layer separation circuit 19 obtains the layer number Ln (n = 1) and the sector address SAd (= 256). To be When the recording data is MPEG standard video data as described above, the decoding time can be minimized by setting the first picture of the second layer to be a so-called intra (I picture).

It should be noted that some time is required while the focal lengths of the pickups 12a and 12b move between layers.
However, data corresponding to that time can be stored in the ring buffer memory 17, and continuous reproduction of moving images is ensured.

If insufficient, there are the following solutions. For example, in the outermost circumference of the first layer and the outermost circumference of the second layer,
Since the same data is written, it is possible to reverse the moving direction of the pickup in the middle of the track.

As another method, immediately before the end of the first layer, for example, when the sector address reaches around 253 and 254, as long as the ring buffer memory 17 does not overflow all the subsequent data, the ring buffer memory 1
I will write in 7. Normally, the ring buffer memory 17
Is because there is a margin in the amount of data storage so that underflow and overflow do not occur. Therefore, if the number of sectors is fixed, a predetermined number is written, and if it is variable, a flag for inversion is written in the subcode of a certain sector.

The above-mentioned configuration of FIG. 16 is a disc reproducing apparatus, but a disc recording apparatus can be constructed by using a recordable disc such as a magneto-optical disc or a phase change type disc as the optical disc 11. in this case,
The sector synchronization signal, sector address, etc. are preformatted, and at the time of recording, data is recorded at a predetermined position by using these preformatted information.

In the above description, the uppermost recording layer is the recording direction from the inner side to the outer side, but the recording direction may be set in the opposite direction. Further, although the spiral track is formed as an example, the present invention can be similarly applied to the case where the tracks are formed concentrically.

[0103]

As described above, in the data recording medium of the present invention, since the recording directions of the multiple recording layers are set alternately, the transition between layers becomes fast and easy, and quick access is possible. . Further, in the recording / reproducing apparatus for such a data recording medium, transition between recording / reproducing between layers is smoothly performed, and high-speed access is possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing area division of an embodiment of a disc according to the present invention.

FIG. 2 is a schematic diagram for explaining a recording direction according to an embodiment of the present invention.

FIG. 3 TOC provided on a disc according to the present invention
It is an approximate line figure showing an example of the position of.

FIG. 4 is a schematic diagram showing an example of sector division of a disk according to the present invention.

FIG. 5 is a schematic diagram illustrating an example of a sector address and another example.

FIG. 6 is a schematic diagram showing an example of a layer field.

FIG. 7 is a schematic diagram illustrating an example of data indicating the total number of layers in a layer field.

FIG. 8 is a schematic diagram illustrating an example of data indicating a layer number in a layer field.

FIG. 9 is a schematic diagram for explaining still another example of the sector address.

FIG. 10 is a schematic diagram for explaining another example of the position of the TOC.

FIG. 11 is a schematic diagram for explaining a data layout of the first TOC.

FIG. 12 is a schematic diagram for explaining the layout of a disk entry in the first TOC.

FIG. 13 is a schematic diagram for explaining a layout of layer entries in the first TOC.

FIG. 14 is a schematic diagram for explaining the layout of track entries in the first TOC.

FIG. 15 is a schematic diagram for explaining a data layout of an additional TOC.

FIG. 16 is a schematic diagram for explaining a layer configuration and identification information.

FIG. 17 is a schematic view of an embodiment of a disc reproducing apparatus according to the present invention.

FIG. 18 is a block diagram of an embodiment of a disc reproducing apparatus according to the present invention.

[Explanation of symbols] 1,11 Disk 2 Inner guard area 3 Program area 4 Outer guard area

Claims (6)

[Claims] 1. A data recording medium in the form of a disc, wherein identification information corresponding to the number of recording layers on both sides is written in a predetermined area of the recording layer. 2. A disc-shaped data recording medium having recording layers on both sides, wherein a multi-layer recording layer is provided on at least one side, and an identification corresponding to a reproduction order of the recording layers in a predetermined area of the recording layer. A data recording medium on which information is written. 3. A data recording means for recording data on a disk-shaped data recording medium, and the data recording means so that identification information corresponding to the number of recording layers on both sides is written in a predetermined area of the recording layer. A recording device having identification information generating means for supplying identification information to the recording medium. 4. A data reproducing means for reproducing data from a disk-shaped data recording medium, and identification information corresponding to the number of recording layers on both sides and written in a predetermined area of the recording layer of the reproducing means. A reproducing apparatus provided with identification information extracting means for extracting from the output. 5. A data recording means for recording data on a disc-shaped data recording medium, and the data recording means so that identification information corresponding to the number of recording layers on both sides is written in a predetermined area of the recording layer. A recording / reproducing apparatus comprising: identification information generating means for supplying identification information to the recording medium; data reproducing means for reproducing data from the data recording medium; and identification information extracting means for extracting the identification information from the output of the reproducing means. 6. A data reproducing means for reproducing data from a disc-shaped data recording medium, and identification information written in a predetermined area of a recording layer and corresponding to a reproducing order of the recording layer is extracted from an output of the reproducing means. And a reproduction device including identification information extracting means.