JPH07182839A - Method of recording digital data - Google Patents

Abstract

PURPOSE:To provide a digital data recording method efficiently realizing the high speed search of the digital data on a magnetic tape at a low cost. CONSTITUTION:When blocks are recorded on the magnetic tape 6 in frame unit, numbers are added to respective blocks in an ascending order to be recorded. At this time, the blocks are recorded in an area 3 on the track successively. When the block Bs-m is regarded as the block where recording is started first in the frame (m), the number Bs-m is recorded in a subcode area 4 on the track. Further, when no block where recording is started exists in the frame, information showing that no block where recording is started exists is recorded in the subcode area 4 on the track instead of the number Bs-m.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording a digital signal on a recording medium such as a tape or a disc.

[0002]

2. Description of the Related Art A conventional digital data recording method
A data recording / reproducing apparatus using an AT (Digital Audio Tape recorder system) will be described as an example. In this data recording / reproducing apparatus, the data recorded on the magnetic tape is
Data transferred by a host such as a computer,
The transferred data can be broadly divided into two types of data, auxiliary data that is information for explaining the transferred data. further,
The recording / reproducing apparatus automatically adds information on the start and end points of the magnetic tape, information for delimiting blocks, an address indicating a position on the magnetic tape, information for error detection or correction, and the like.

The host divides the data into blocks. The data divided by this host is called a block, and the block is the smallest unit that can be recorded on the magnetic tape. Also, a specific block can be a mark block. In the recording / reproducing apparatus, blocks and mark blocks are numbered and recorded. By specifying the number absolutely, it is possible to reproduce the data of the block or mark block of that number. Also,
By relatively designating the numbers of the blocks and mark blocks, it is possible to designate the block four blocks later, for example, and reproduce the data of the desired block or mark block.

Of these, a conventional method of recording a numbered block or mark block will be described with reference to the drawings.

FIG. 3 is a diagram in which blocks and mark blocks are sequentially recorded on a magnetic tape by a conventional recording / reproducing apparatus. Reference numeral 18 is a frame composed of n tracks, where n is an integer, 19 is a block, and 20 is a magnetic tape. The blocks and mark blocks are numbered in the order in which they were transferred,
It is recorded. Here, the block numbered i is represented as block i, and the number assigned to the block is simply represented as the block number.

As a first example, the first in the frame
The number g of the block g from which recording was started and the frame
Number of blocks where recording was started in_gThe subcode
On a track called "," where data can be picked up even when searching
Record in the area frame by frame. If you record like this
In this case, the search method described below is possible. Service
G and m_gIf you can play
The block number where the recording started is from g to g + m_g-1
Recording of the desired block starts because it turns out that there is
Move to the specified frame to get the desired block
It is possible. Similarly, for mark blocks,
The mark block h in which recording is first started in the frame
Number and mark block where recording was started within the frame
Number of m _hIs recorded in the subcode frame by frame. Service
H and m_hIf you can play back, record in that frame
Mark block number h to h + m_h-1
It turns out that the desired mark block
Move to the frame where the
It becomes possible to live.

Further, as a second example, instead of the number of the block where the recording is started in the frame of the first example,
There is also a method of indicating the number of the block existing in the frame by using the number of the block which has been recorded in the frame.

[0008]

However, in the above-mentioned first and second conventional examples, it is necessary to record two types of information in order to record a numbered block or a mark block, and at the time of search. After reproducing the two kinds of information and performing an operation, it is necessary to compare with the number of a desired block or mark block. Therefore, there is a problem that an area for recording two kinds of information is required for the search, and a circuit and time for the operation are required.

[0009]

According to the present invention, in order to solve the above-mentioned problems, when recording a block having a unique number different from each other, information on the number assigned to each block is also recorded. Have a configuration.

[0010]

With this configuration, the present invention records the digital data so that the desired block can be searched at high speed by recording the information about the number given to the block together with the block.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a layout diagram on a magnetic tape according to an embodiment of the present invention. FIG. 1A is a diagram of tracks recorded on a magnetic tape. Reference numeral 1 is a track, 2 is a tracking information area, 3 is a data area, 4 is a subcode area, and 5 is a gap.

The tracking information area 2 is allocated with information used by the head to accurately trace the center of the track and information for knowing the position of the head within the track. Data is assigned to the data area 3. The sub-code area 4 is assigned data that needs to be reproduced even during high-speed search. The gap 5 is a buffer area for insert recording.

FIG. 1B is a layout diagram of blocks in the data area 3 according to an embodiment of the present invention. 6 is a magnetic tape, 7 is a frame composed of n (n is an integer) tracks, and 8 and 9 are blocks. Here, a block numbered i is referred to as a block i, and a number assigned to the block is referred to as a block number. A frame m is the m-th frame (m is an integer) from the start of the magnetic tape.

When the blocks are recorded on the magnetic tape 6 in units of frames, each block is sequentially numbered and recorded in ascending order. At this time, blocks are sequentially recorded in the area 3 on the track. If the block Bs-m in the frame m is the block where the recording is first started, the number Bs-m
Is recorded in the subcode area 4 on the track. Further, when there is no block where recording is started in the frame, information indicating that there is no block where recording is started is recorded in the subcode area 4 on the track instead of the number Bs-m. Of the blocks thus recorded, a desired block B is searched for as follows.

When B> Bs-m, a search is performed from the start end side of the magnetic tape to the end direction, and the magnetic tape is moved to frame k where B≤Bs-k. If B = Bs- (m + k), the desired block B exists in the frame. Also, B <
In the case of Bs- (m + k), it means that the desired block B was present in the frame m, so the search speed is inverted and the process returns to the frame m. Here, if there is a frame z in which a block in which recording has started does not exist in the middle, Bs-m
Since the information that there is no block in which a recording is started is recorded in the frame, if the frame is ignored, it is possible to move to the frame in which the desired block exists without contradiction.

In the case of the search from the end side to the start end direction of the magnetic tape, first, when B <Bs-m, the search from the end side to the start end direction is started. At this time, when B ≧ Bs-m, the frame in which the desired block exists is determined. The point different from the search from the start side to the end side is that there is no operation of going past the frame and returning.

As described above, when the blocks are recorded on the magnetic tape in units of frames, each block is sequentially numbered, and the number assigned to the block where the recording is first started in the frame is recorded together with the blocks. However, it is possible to perform a search by recording information indicating that there is no block in the frame where recording is started, in the place where the number of the block in which recording is first started is recorded. . Since a search can be performed without performing an extra operation such as addition, a high-speed search can be realized at a lower cost than before. Moreover, since only one type of information is recorded, the area for that is small.

Although the above method alone is effective, the efficiency of the search can be further improved by marking the block and recording. Here we set a flag on the block,
When the flag is on, it is called a mark block with a mark added.

When the mark blocks are recorded on the magnetic tape 6 on a frame-by-frame basis, the mark blocks are sequentially numbered and recorded in ascending order. If the mark block Ms-m is the mark block in which the recording is first started in the frame m, the number Ms-m is assigned to the subcode area 4 on the track.
To record. If there is no mark block for which recording has started in the frame, information indicating that there is no mark block for which recording has started is recorded in the subcode area 4 on the track instead of the number Ms-m. Of the mark blocks thus recorded, a desired mark block M is searched for as follows.

When M> Ms-m, a search is performed from the start end side of the magnetic tape to the end direction, and the magnetic tape is moved to the frame k where M≤Ms-k. If M = Ms- (m + k), the desired mark block M exists in that frame. If M <Ms- (m + k), it means that the desired mark block M was present in the frame m, and therefore the search speed is reversed and the process returns to the frame m. Here, if there is a frame z in which no mark block for which recording has started exists in the middle, since information indicating that there is no mark block for which recording has started within a frame is recorded in Ms-m,
By ignoring that frame, it is possible to move to the frame where the desired mark block exists without contradiction.

In the case of searching from the end side to the start end direction of the magnetic tape, first, when M <Ms-m, the search from the end side to the start end direction is started. At this time, when M ≧ Ms-m, the frame in which the desired mark block exists is determined.
The point different from the search from the start side to the end side is that there is no operation of going past the frame and returning.

Further, as an improvement of the operation of returning too much when a search is performed, when the blocks are recorded on the magnetic tape 6 in a frame unit, each block is sequentially numbered in ascending order and recorded. In the frame m, the number Bs-m of the block Bs-m where the recording is first started and the number Be of the block Be-m where the recording is last started in the frame m
There is a method of recording two types of -m in the subcode area 4 on the track in the frame m. By doing this, the information to be recorded increases from one type to two types, but in the case of searching from the start side of the magnetic tape to the end direction, the number Be-m of the block where the recording is started last in the frame is used. If it goes too far, there will be no movement to return. Since there is no change in that the information used for comparison at the time of the search can be kept as it is, it is possible to eliminate the operation of going too far while keeping the effect of the inexpensive and efficient high speed search.

Further, two types of the mark block Ms-m number Ms-m recorded first in the frame m and the mark block Me-m number Me-m recorded last in the frame m are framed. If you record in area 4 on the track in m,
Similarly, in the search of the mark block, it is possible to eliminate the operation of going too far and returning.

In this embodiment, the blocks are sequentially numbered in the ascending order, but may be in the descending order. In that case, the magnitude relationship to be compared is different, but the idea is as described above, and the description is omitted here. Also,
Although one type of mark block is used in this embodiment, a plurality of types of mark blocks may be used.

FIG. 2 is a block diagram of an embodiment of a recording / reproducing apparatus to which the digital data recording method of the present invention can be applied. Reference numeral 11 is a formatter, 12 is a deformatter, 13 is a recording / reproducing changeover switch, 14 is a controller, 15 is a recording / reproducing mechanism control circuit, 16 is a head,
Reference numeral 17 is a recording medium.

At the time of recording, the switch 13a and the switch 1
3b is connected to the Rec terminal, and the input digital data is input to the formatter 11 as a block.
An instruction for processing the input block is input to the controller 14, and the controller 14 generates auxiliary data as information for explaining each block and outputs the auxiliary data to the formatter 11. The formatter 11 performs predetermined recording signal processing such as error correction coding and modulation as data capable of recording blocks and auxiliary data, converts the recording signals into recording signals, and records the recording signals on the recording medium 17 by the head 16. When the controller 14 outputs information such as the recording start point and the recording end point to the formatter 11,
The formatter 11 also generates a recording signal indicating these states. The recording / reproducing mechanism control circuit 15 performs a recording operation in response to a command from the controller 14.

At the time of reproduction, a command for instructing a desired block is input to the controller 14 and switches 13a and 13
b is connected to the PB terminal side. A reproduced signal reproduced from the recording medium 17 by the head 16 is input to the deformatter 12, and predetermined reproduced signal processing such as demodulation and error correction decoding is first performed. Then, the auxiliary data is extracted, and the auxiliary data is output to the controller 14. Controller 14
On the basis of the auxiliary data and the input command, it outputs to the recording / reproducing mechanism control circuit 15 an instruction to perform a search operation for the required data and a reproducing operation for the data after the position of the required data is known. The controller 14 specifies the position of the block to be output in the reproduced data to the deformatter 12, and the deformatter 12 separates and outputs the specified block.

As described above, the digital data recording method of the present invention can be realized by the recording / reproducing apparatus.

[0030]

As described above, according to the digital data recording method of the present invention, when recording blocks each having a unique number different from each other, by recording the information about the number assigned to each block, It is possible to realize a high-speed search for digital data that is cheaper and more efficient than before.

[Brief description of drawings]

FIG. 1 is a layout diagram on a magnetic tape for explaining a digital data recording method according to an embodiment of the present invention.

FIG. 2 is a block diagram of an embodiment of a recording / reproducing apparatus to which the digital data recording method of the present invention can be applied.

FIG. 3 is a layout diagram on a magnetic tape for explaining a conventional digital data recording method.

[Explanation of symbols]

 1 Track 2 Tracking Information Area 3 Data Area 4 Subcode Area 5 Gap 6 Magnetic Tape 7 Frames 8 and 9 Blocks

Claims (7)

[Claims] 1. A method of recording digital data on a recording medium, which relates to the number assigned to each block together with the block data when the block data to which different unique numbers are respectively attached is recorded. A digital data recording method characterized by recording information together. 2. The digital data recording method according to claim 1, wherein the blocked data is recorded in numerical order. 3. The digital data recording method according to claim 2, wherein the information about the number has the same content in n track sections (where n is an integer). 4. The number-related information is a number given to the first block-blocked data of the block-blocked data when there is block-blocked data to be recorded in the n-track section. If there is no block data to start recording in the n track section,
4. The digital data recording method according to claim 3, wherein the information is information indicating that there is no blocked data for which recording is started in the track section. 5. The information regarding numbers is information regarding numbers attached to blocked data in which data related to the numbers attached to the respective blocked data is stored. Digital data recording method described. 6. The information regarding the number given to each block data is the block data recorded first in the block data when recording is started in n track sections. It is a number attached to the data, and when there is no blocking data to start recording in the n track section, it is information indicating that there is no blocking data to start recording in the n track section. 6. The digital data recording method according to claim 5, wherein 7. Information regarding the number given to the blocked data in which the related data is stored, in the case where there is the blocked data whose recording is started in an n-track section, among the blocked data, It is information regarding the number given to the block data to be recorded first, and when there is no block data to start recording in the n track section, the block formation to start recording in the n track section 6. The digital data recording method according to claim 5, wherein the information is information indicating that there is no data.