JPH08212561A - Data recording medium and recording/reproducing device using the same - Google Patents

Abstract

PURPOSE: To enable a multilayered disk to be accessed at a high speed. CONSTITUTION: Inner guard areas 2, program areas 3 and outer guard areas 4 are formed in respective layers of a multilayered disk 1 and positions in the radial direction of these areas are made to coincide with each other. The recording direction in the uppermost layer is made to be a recording direction heating from the inner peripheral side to the outer peripheral side and the recording direction in the next layer is made to be a recording direction heading from the outer peripheral side to the inner peripheral side. In this manner, recording directions are made alternative. Then, the recording completion position of the uppermost first layer and the recording start position of the next second layer are made to be at the same radial position.

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.

[0003]

By the way, 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, it does not consider recording and reproducing video data and / or audio data using a compression code.

For example, in a conventional CD (compact disc), recording tracks are formed from the inner circumference to the outer circumference of the disc. 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.

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

[0006]

In order to achieve the above-mentioned object, the present invention is a disk-shaped data recording medium, which has at least first and second recording layers, and the order of recording data. Is defined as a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording directions of the first recording layer are the first and second recording directions. The recording direction of the second recording layer is the other of the first recording direction and the second recording direction, and the data area of each layer has a sector structure for data, and at least each sector has a first recording area. And a layer number for identifying the second recording layer is written.

In the data area of each layer, the data has a sector structure, and at least each sector is
It is characterized in that the total number of recording layers on the disc is written.

Further, a recording area is provided so that the inner guard area and the outer guard area of each layer are overlapped with each other.
In the OC area, at least data for accessing all layers and data for identifying each layer are provided.

Further, the TOC area of the uppermost layer is provided in a place adjacent to the data area of the uppermost layer. The data area of each layer has a sector structure, and the sector number of each sector has a numbering system that allows at least the layer number to be identified.

Further, the recording / reproducing apparatus of the present invention using the data recording medium of the present invention makes access by utilizing the recording layer of the data recording medium, its TOC area, sector structure and the like.

[0011]

The data recording medium of the present invention is easy to access due to the structure of the recording track. Therefore, the recording / reproducing apparatus of the present invention using the data recording medium of the present invention can be accessed at high speed and easily.

[0012]

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

Next, the structure of each layer will be described with reference to FIG.
First, in the present invention, a spiral recording track may be 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. Furthermore, for multiple layers, from the inner circumference to the outer circumference,
Recording layers alternate from the outer circumference to the inner circumference.
Further, as an example, the even-numbered layers L0, L2, ...
Are odd-numbered layers L1, L3, ...
Is recorded from the outer circumference to the inner circumference. Here, the even / odd numbers indicate the reference numbers given to the layer L for the purpose of explanation, and the uppermost layer is L0 which is the even number 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 size of the disk is the same as that of a normal CD, it is possible to identify the type of the disk that is erroneously mounted.

Returning to FIG. 1 again, the program areas on the disc are arranged so that their ends are roughly aligned. 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 the data is stored at the same radius as the inner circumference of the upper layer. Try to finish. 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 blank data is not recorded, the sector header information may not be found if the read layer is changed by performing a focus jump from the recorded 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, regarding TOC (Table Of Contents),
This 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, in each of the even-numbered layer and the odd-numbered layer, the position for recording the TOC of IGA or OGA is unified. 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, when both a conventional single-layer disc and a multi-layer disc are allowed as standards, an ID for identifying whether this disc is a single-layer disc or a multi-layer disc is written in TOC00. As another example, TOC00 records information identifying how many layers the multilayer disc is composed of. Also, by linking TOC0 to TOCn of each layer,
In response to the access request, it is possible to determine which layer TOC is accessed first and then TOC00. Further, 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 the area of the outer periphery any more. 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.

In addition to the 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, it is conceivable that the layer information included in the subcode SC has 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 number of recording layers of 3 bits (b5 to b3) and 3 bits (b2 to b) in the layer field of 1 byte.
It has a layer number field of 0).

The definition of the layer number is shown in FIG. Only layer numbers L0 and L1 are defined here, but the usage of this field is similar to that illustrated in FIGS. 5A and 5B.

The definition of the total number of records is shown in FIG. here,
1 and 2 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.

Further, another example of sector header information such as a 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 that 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 specified as described above. I of layer L0
The sector address of the last sector of the GA (inner guard area) is set to (-1). IG3-The track numbers of all sectors 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 the 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 [mm] of the outer diameter 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.

The "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 (2's complement code) 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's 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.

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, a large amount of data, for example, MPEG (Moving Pict)
FIG. 16 shows a variable rate compatible data (encoding) decoding device as an example of a device used when recording and reproducing a digitalized moving image according to the ures Expert Group) standard.

In FIG. 16, the data recorded on the optical disk 11 is reproduced by the pickup 12. The pickup 12 irradiates the optical disc 11 with laser light and reproduces the data recorded on the optical disc 11 from the reflected light. The signal reproduced by the pickup 12 is sent to the demodulation circuit 13. The demodulation circuit 13 demodulates the reproduction signal output from the pickup 11 and outputs it to the sector detection circuit 14.

The sector detection circuit 14 detects sector data recorded for each sector from the supplied data and supplies it to the layer separation circuit 29. The layer separation circuit 29 separates the sector address and the layer number from the sector data. 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 in the subsequent stage in the sector synchronization state.
Further, when the sector detection circuit 14 cannot detect an address or the detected addresses are not consecutive, for example, the ring buffer control circuit 1
The sector number abnormality signal is output to the track jump determination circuit 28 via 6. Further, when the layer separation circuit 29 cannot detect the discontinuity of the layer numbers or the detected layer numbers are not the same, for example, the layer separation circuit 29 causes a track jump of the layer number abnormal signal via the ring buffer control circuit 16. Output to the determination circuit 28.

The ECC circuit 15 detects an error in the data supplied from the sector detection circuit 14, corrects the error using the redundant bit added to the data, and a ring buffer memory (FIFO) 17 for track jump. 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 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 and outputs a track jump signal to the tracking servo circuit 17 when a track jump is required to make the reproduction position of the pickup 12 on the optical disk 11 track jump. It is like this. Further, the track jump determination circuit 28
Is a sector number abnormal signal from the sector detection circuit 14,
A layer number abnormal signal from the layer separation circuit 29 or an error occurrence signal from the ECC circuit 15 is detected, a track jump signal is output to the tracking servo circuit 27, and the reproduction position of the pickup 12 is 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-mentioned MPEG standard, and includes an intra-frame code picture (usually I picture), an inter-frame prediction code picture (usually P picture), and an inter-frame bidirectional prediction 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-mentioned data decoding apparatus will be described. The pickup 12 irradiates the optical disc 11 with laser light, and reproduces the data recorded on the optical disc 11 from the reflected light. The pickup 12
The reproduced signal output by is input to the demodulation circuit 13 and demodulated. The data demodulated by the demodulation circuit 13 is input to the ECC circuit 15 via the sector detection circuit 14 and error detection and correction are performed. If the sector number (address assigned to the sector of the optical disk 11) is not normally detected by the sector detection circuit 14,
An abnormal sector number signal is output to the track jump determination circuit 28. The ECC circuit 15 outputs an error occurrence signal to the track jump determination circuit 28 when uncorrectable data is generated. The data for which the error has been corrected is E
It is supplied from the CC 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 number LNo.
And sector address SAd. The layer number and the sector address are both the ring buffer control circuit 16
Is supplied to. When the layer number (layer number recorded in the sector of the optical disk 11) is not detected normally in the layer separation circuit 29, the track jump determination circuit 2
A layer number abnormal signal is output to 8. The ring buffer control circuit 16 receives the layer number LNo. And sector address SAd are read, and the write address (write pointer (WP)) on the ring buffer memory 17 corresponding to the address is designated.

When the optical disk 11 is reproduced by the data decoding device for the first time, the information as to whether the optical disk 11 is a single layer or a plurality of layers and, in that case, how many layers is provided? , 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.

The ring buffer control circuit 16 also designates 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 31.

The audio code buffer 25 uses the remaining amount of the internal code buffer to determine 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 32.

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 concerning 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, so the track jump determination circuit 28. Determines that error recovery is possible by replaying the error occurrence position with the pickup 12, and outputs a track jump command to the tracking servo circuit 27.

When a track jump command is output from the track jump determination circuit 28, the tracking servo circuit 27 causes the reproduction position by the pickup 12 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 before jumping, that is, the sector number obtained from the sector detecting circuit 14 becomes the sector number at the time of track jump. Until, the ring buffer memory 17 for new data
Is prohibited, and the data already stored in the ring buffer memory 17 is transferred to the multiplexed data separation circuit 18 as needed.

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 reaches a predetermined address, for example (255). The ring buffer control circuit 16 which has detected the predetermined address supplies the layer switching signal SL to the focus servo circuit 30 and the tracking servo circuit 27. The focus servo circuit 30 switches the focus of the pickup 12 from the first layer to the second layer. Meanwhile, the tracking servo circuit 27 turns off the tracking servo once, and turns on the tracking servo after the focus is switched to the second layer. The tracking servo is turned off once while the focus is moved from the first layer to the second layer.
This is because the tracking error signal cannot be obtained.

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 length of the pickup 12 moves between layers. However,
Data corresponding to the time can be stored in the ring buffer memory 17, and continuous reproduction of moving images is ensured.

Further, in the case of 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-described 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.

[0089]

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

[Explanation of symbols]

 1,11 Disc 2 Inner guard area 3 Program area 4 Outer guard area

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G11B 27/00 D 27/10 C (72) Inventor Jun Yoneman 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Tomihiro Nakagawa 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (10)

[Claims] 1. A disc-shaped data recording medium, comprising at least a first and a second recording layer, wherein data is recorded in a first recording direction from the inner circumference to the outer circumference and from the outer circumference. A second recording direction toward the inner circumference is defined, the recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is The data area of each layer is the other of the first and second recording directions, and the data has a sector structure, and at least each sector has a layer number for identifying the first and second recording layers. A data recording medium characterized by being written. 2. The data recording medium according to claim 1, wherein the data recorded in the data areas of the first and second recording layers is defined to have a sector structure, and at least each sector has at least one sector structure. A data recording medium having the above layer number written therein. 3. The data recording medium according to claim 1, wherein the data recorded in the data areas of the first and second recording layers is defined to have a sector structure, and at least each sector has at least one sector structure. A data recording medium in which the total number of recording layers on a disc is written. 4. The data recording medium according to claim 1, wherein the data end portion of the first recording layer and the data start portion of the second recording layer are located on a circle having substantially the same radius. Characteristic data recording medium. 5. A recording direction having at least first and second recording layers, wherein data is recorded in a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is one of the first and second recording directions. On the other hand, the data area of each layer has a data sector structure, and at least each sector has a layer number for identifying the first and second recording layers written therein. A recording apparatus comprising means for recording data with respect to. 6. A recording direction having at least first and second recording layers, wherein data is recorded in a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is one of the first and second recording directions. On the other hand, the data area of each layer has a sector structure in which data is recorded on a disc-shaped data recording medium in which the total number of recording layers on the disc is written in at least each sector. A recording device characterized by being provided. 7. A recording direction having at least first and second recording layers, the data recording order being a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is one of the first and second recording directions. On the other hand, the data area of each layer has a data sector structure, and at least each sector has a layer number for identifying the first and second recording layers written therein. A reproducing apparatus comprising means for reproducing data from the reproducing apparatus. 8. A recording direction having at least first and second recording layers, the data recording order being a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is one of the first and second recording directions. On the other hand, the data area of each layer has a sector structure, and at least each sector is provided with means for reproducing data from a disc-shaped data recording medium in which the total number of recording layers on the disc is written. A playback device characterized by the above. 9. A recording direction having at least first and second recording layers, wherein data is recorded in a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is one of the first and second recording directions. On the other hand, the data area of each layer has a data sector structure, and at least each sector has a layer number for identifying the first and second recording layers written therein. A recording / reproducing apparatus including means for recording data and means for reproducing data from the data recording medium. 10. At least first and second recording layers are provided, and as a data recording order, a first recording direction from the inner circumference to the outer circumference and a second recording direction from the outer circumference to the inner circumference. The recording direction of the first recording layer is one of the first and second recording directions, and the recording direction of the second recording layer is one of the first and second recording directions. On the other hand, the data area of each layer has a sector structure in which data is recorded on a disc-shaped data recording medium in which the total number of recording layers on the disc is written in at least each sector. A recording / reproducing apparatus comprising means for reproducing data from the data recording medium.