JPH09237469A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flexibly correspond a data recording rate to a data transfer rate by obtaining the number of divided blocks for one track recording on a tape and the number of data recorded blocks in the number of these divisions based on the data transfer rate of the data transferred to the device and the recordable maximum data recording rate of the device, and controlling the write-in from these calculation results. SOLUTION: By a data transfer rate detecting device 22, the data transfer rate of a signal S11 from a signal transmitting device 21 is detected and the signal S11 is divided into blocks by making the time required for recording one track as one period, and this signal S12 is once stored in a time base conversion memory 23, and with a signal S14 processed for conversion from the stored signal S13, the number of blocks N and M are decided so as to follow to a specified formula in an N.M specifying device 25. Then a signal S15 corresponded to the decided number of blocks N and M is supplied to a modulation/electromagnetic conversion device 26 and the data are recorded on the magnetic tape 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type magnetic recording / reproducing apparatus using, for example, a rotary head.

[0002]

As is well known, VTR (Video Tape Reco
rder), DAT (Digital Audio Tape Recorder), and the like, in a recording / reproducing system that records and reproduces data using a magnetic tape as a recording medium, achieves high density and high fidelity recording / reproducing as much as possible. Therefore, a magnetic recording / reproducing apparatus is widely used in which an information signal such as an audio signal is converted into digitized data by a PCM (Pulse Code Modulation) technique, recorded on a magnetic tape, and reproduced.
As this magnetic recording / reproducing apparatus, for example, there is a rotary head type in which a magnetic tape is wound around a cylindrical drum provided so that the head rotates along the peripheral side surface, and a helical scan is performed.

In this magnetic recording / reproducing apparatus,
There is a method of recording a plurality of signals having different contents on one magnetic tape in parallel. First, as a first method, there is a method in which one track is made into 6 tracks and a maximum of 6 types of PCM audio signals are recorded on all tracks, for example, as in the case of 8 mm VTR multi-track recording. Then, as a second method, for example, as in multi-channel recording of a digital VTR, a signal in which a plurality of different information is mixed is recorded on a track, and at the time of reproduction, a signal output is performed by using the signal recorded on the track. This is the method of choice.

By the way, in the above-mentioned recording method of the conventional magnetic recording / reproducing apparatus, in the first method, basically, the data transfer rate of a signal sent from the outside to the magnetic recording / reproducing apparatus and the magnetic recording / reproducing apparatus side. Since the data recording rate of the data is standardized to be 1: 1, when the data transfer rate is slower than the data recording rate, a fixed amount of the signal sent from the outside is temporarily stored in the buffer memory unit, This is recorded on the magnetic tape by the magnetic recording / reproducing apparatus. In this case, since the data transfer rate of the signal sent from the outside is slower than the data recording rate, the magnetic recording / reproducing apparatus may repeat "recording / stopping" at a very short time interval if the buffer memory capacity is small. Therefore, it is not possible to flexibly deal with data recording on the magnetic tape, and the stable running of the magnetic tape is likely to be adversely affected.

In the second method, for example, when the data transfer rate of the signal sent from the outside is 1/2 the data recording rate of the data on the magnetic recording / reproducing apparatus side, the tape speed is reduced to 1 / normal. With the double azimuth head in the state of being slowed down to 2, continuous "recording / non-recording" for each scanning of the head, so that the data transfer rate of the signal sent from the outside can be set to the data transfer rate of the data on the magnetic recording / reproducing apparatus side. The recording rates are adapted to each other.

Therefore, when the data transfer rate of the signal sent from the outside is slower than the data recording rate of the data on the magnetic recording / reproducing apparatus side, it is necessary to slow the tape speed, and the magnetic tape is transported. Since the rotation speed of the capstan must be slowed down, it becomes difficult to control the rotation of the capstan and the tape running becomes unstable. Further, the conventional magnetic recording / reproducing apparatus has a drawback that it can only support a predetermined data transfer rate of a signal.

Further, the conventional magnetic recording / reproducing apparatus adjusts the data recording rate to the signal sent from the outside at a slow data transfer rate by lowering the rotational speed of the rotary head in a state where the tape speed is slowed. Even in such a case, it becomes difficult to control the rotation of the capstan. Furthermore, since the number of rotations of the rotary head changes, the amount of air film between the magnetic tape and the rotary head also changes, leading to instability of head touch of the rotary head on the magnetic tape.

[0008]

As described above, in the conventional magnetic recording / reproducing apparatus, when the data transfer rate of the signal sent from the outside is slower than the data recording rate on the magnetic recording / reproducing apparatus side, the data recording rate. "Recording / stopping" is repeated with respect to the running magnetic tape in order to match with the data transfer rate, and there is a problem that the magnetic tape is adversely affected. Further, in order to match the data recording rate with the data transfer rate, the rotation speed of the capstan or the rotary head is changed, so that the tape running becomes unstable or the touch of the rotary head to the magnetic tape becomes unstable. Has the inconvenience of causing. Furthermore, when the data transfer rate of the signal sent from the outside is slower than the data recording rate of the signal on the device side, a large-capacity buffer memory is required to match the data recording rate with the data transfer rate.
It will cause economic disadvantage.

An object of the present invention is to make it possible to flexibly adapt the data recording rate to the data transfer rate without changing the tape speed or the number of rotations of the rotary head without requiring a large capacity buffer memory. An object of the present invention is to provide a magnetic recording / reproducing apparatus capable of obtaining stable tape running and head touch and maximizing effective use of tape.

[0010]

A magnetic recording / reproducing apparatus according to the present invention is intended for a magnetic recording / reproducing apparatus which records / reproduces data by helically scanning a magnetic tape using a rotary head. There is.

Then, a signal supply source for generating and outputting a signal, a data transfer rate detecting means for detecting a data transfer rate of a signal output from the signal supply source for a certain unit time, and data recording in the apparatus are possible. Based on the maximum data recording rate and the data transfer rate detected by the data transfer rate detecting means, the block division number N for one track to be recorded on the magnetic tape and the number of data recording blocks within this block division number N Based on the block number calculation means for calculating the value of M, the block division number N calculated by the block number calculation means, and the value of the data recording block number M of the block division number N, the rotary head for recording is selected. On the other hand, a recording head control means for controlling the writing of data to the magnetic tape is provided.

According to this structure, the data transfer rate of the signal sent from the outside and the data recording rate of the magnetic recording / reproducing apparatus side can be substantially matched without changing the tape running speed of the magnetic tape. Further, it is possible to efficiently perform recording by using a fixed width of the magnetic tape without requiring a large capacity buffer memory. Further, the data transfer rate of the signal sent from the outside and the data recording rate on the magnetic recording / reproducing apparatus side can be made substantially the same without changing the running speed of the magnetic tape and the rotational speeds of the capstan and the rotary head. Therefore, stable running of the tape and good head touch on the magnetic tape of the rotary head can be realized.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, the present invention will be described with reference to FIGS. 1 (a) to 1 (c) and 2 (a) to 2 (c). In FIGS. 1A to 1C, reference numeral 11 is a magnetic tape. In the magnetic tape 11, tracks 12 recorded by a rotary head (not shown) are formed with a constant slant angle (in FIG. 1A, five tracks are shown). The arrow A1 in the figure indicates the traveling direction of the magnetic tape 11, and the arrow A2 in the figure indicates the scanning direction of the rotary head.

In the first embodiment, one track 1
The number N of blocks into which 2 is divided is fixed, and of the N blocks, M blocks used for data recording (blocks indicated by diagonal lines in the figure) are variable. In this example, N = 10. The value of M is determined by the data transfer rate of the signal to be recorded. For example, when the data transfer rate transferred to the recording / reproducing apparatus is constant and known throughout the recording period, or when the data transfer rate is not constant and the maximum value of the data transfer rate within the entire recording period is known. ,
Assuming that the maximum data transfer rate is X (kbps) and the maximum recordable data transfer rate when all tracks are used is Y (kbps), M is X ≦ Y × M / N (1) Is determined as the maximum value that satisfies However, when recording data on the magnetic tape 11, various signals such as an error correction signal and an address signal are added to a predetermined position of the data. Therefore, the data added for each recording block is the data amount of one block. The number M of data recording blocks is determined as the maximum value that satisfies X ≦ Y × {M × (1-1 / Z) / N} (2).

According to the above method, the magnetic tape running speed remains the same as that of the conventional standard, the intermittent recording of the data is not performed, and the constant width of the magnetic tape 11 can be maintained without the need for a large capacity memory. It can be used for efficient data recording.

When additionally recording data in the (NM) block portion of the magnetic tape 11 recorded by the above method,
Since the unrecorded magnetic tape portion is used, assuming that the data transfer rate at this time is X ', from the equation (2), X'≤Y × {(NM) × (1-1 / Z) / N} (3) Select M such that Further, if there is a portion where M of the data portion that has already been recorded increases from the middle of the additional recording, the formula (3) cannot be satisfied, and an accident may occur in which the additional recording becomes impossible on the way. Therefore, in the case of additional recording, the value of M of the already recorded data portion, the recording time, and the like are stored in, for example, a memory built in a tape cassette (not shown) or a predetermined location on the magnetic tape 11 (for each track). It is recorded at a predetermined position) so that it can be referred to for additional recording.

Next, when the recorded data is reproduced, error correction is performed. The method of adding the error correction code will be described with reference to FIG.
This will be described with reference to (a) to (d). Error correction is shown in Figure 3.
As shown in (a) to (d), at least one error correction code space 35 is completed with data which is an integral multiple of the data recorded per one block divided into N pieces, It seems to be completed with data that is continuously recorded or reproduced.

For example, the error correction code space 35 is shown in FIG.
As shown in (a), it is assumed that the error correction code 36 has a data amount of 10 blocks, and the error correction code 36 is added to the end of the data of 10 blocks. Furthermore, N = 10 in the recording method of FIG. , When recording data with M = 3,
As shown in FIG. 3B, three blocks of data are recorded on each track. The error correction code space 35 is set to 10
Since the amount of data for the block is set, the error correction code 3
6 is written at the end of the first block of the 4th track.

3C and 3D respectively show
It shows a method of adding the error correction code 36 in the case of M = 4 and M = 10. Here, one specific example of the data recording method will be described with reference to FIGS.
This will be described using (a) to (c).

As shown in FIGS. 1 (a) and 2 (a),
The data recording rate when recording is performed using the entire area of the track 12 is 5 than the data transfer rate of the transmitted signal.
In the case of double speed, M = 2 blocks are used for data recording, and the remaining 8 blocks are used as dummy data 12b (see FIG. 1).
(A)} or the non-recording portion 12e {FIG. 2 (a)}, the apparent data recording rate is approximately matched with the data transfer rate of the signal sent.

The dummy data 12b may be used as tracking data or the like. When data recording is once completed and new data recording is performed, when data is transmitted at a data transfer rate different from the previous data transfer rate, for example, data is transmitted at a speed 2.5 times faster than the above data transfer rate. When it comes, the block M used for recording is set to M = 5 blocks and recorded on the magnetic tape 11.

At this time, the dummy data section 1 recorded after the two data recording blocks 12a previously recorded is recorded.
2b or the non-recording portion 12e may be recorded so as to be overwritten {FIG. 1 (b), FIG. 2 (b)}, or may be recorded in the continuous portion 12c of the previous data recording block 12a. FIG. 1 (c), FIG. 2 (c)}.

Two previously recorded data recording blocks 1
When new data is recorded in the dummy data part 12b recorded after 2a, only the new part may be newly overwritten, or the previously recorded two blocks of data 12a may be read once. It is also possible to overwrite all the one track from the beginning of one track by collecting all the data stored in a copy and adding the new data 12b to the stored data.

The position of the magnetic tape 11 to be recorded and the amount of free space for additional recording can be determined by a memory unit mounted in a cassette containing the magnetic tape 11 or a predetermined amount on the magnetic tape 11. You just have to record it in the position,
The recording position is selected so that the useless area can be reduced based on this information.

The error correction code used during reproduction is such that at least one error correction code space is completed with data that is an integral multiple of the block, and is completed with data that is continuously recorded or reproduced.

The memory required as a buffer at the time of recording is
When the data transfer rate of the signal sent is equal to the data recording rate, 10 blocks (1 track 1 track)
Since all is used for data recording, it is sufficient if there is a memory that can store data for one track.

The position of the data to be recorded and the arrangement order of the blocks can be set to any position on the track 12, and the operating direction of the rotary head and the running direction of the magnetic tape 11 are also shown in FIGS. There is no particular need to comply as shown in FIG.

Next, the second recording method when the data transfer rate is not constant and the maximum value of the data transfer rate within the entire recording period is known will be described. In the recording method of the first embodiment, the maximum value X of the data transfer rate is
In accordance with the above, M was determined, and M was kept constant over the entire recording period. Therefore, while the data transfer rate is temporarily reduced, there is a so-called wasted area in which data is not recorded on the magnetic tape 11 or dummy data is recorded, which reduces the utilization efficiency of the magnetic tape 11. . Therefore, here, a recording method in the second embodiment for improving the utilization efficiency of the magnetic tape 11 will be described with reference to FIG.
This will be described with reference to FIG.

Since the data transfer rate of the transferred signal changes every moment, the value of M is first determined based on the equation (2) every time during the recording period of one track. In accordance with this M, recording is performed with an optimum number of blocks for each track. In this method, the value of M for each track on the magnetic tape 11 is not constant {FIG.
(A)｝. Therefore, for each track, the value of M on its own track is recorded at a predetermined location on the track.

On the magnetic tape 11 recorded by this method,
The case of additionally recording new data will be described below. In this case, since the number of recording blocks M at the time of recording is constantly changing, how many recordable blocks N ′ (N ′) are recorded on the magnetic tape 11 before recording each track.
= NM) is always monitored by a reproducing head mounted so as to lead the recording head by one track or more, and a new recording block M is constantly monitored within the remaining recordable block N '. change. Here, changing M means specifying the data transfer rate of the signal to be additionally recorded on the recording device side. Therefore, the device on the data transfer side is limited to a device such as a hard disk drive device that can change the data transfer rate according to the request from the recording device side.

Further, in the first and second embodiments,
Although N was fixed as a fixed value, as another method of determining the effective recording track length according to the data transfer rate of the data to be recorded, this time, M is satisfied so that expression (2) is satisfied.
A method of converting N while keeping N constant may be considered. Also in this case, a method of keeping N constant during the recording period (FIGS. 1 and 2)
Then, there are two methods, that is, a method of constantly changing in accordance with a changing data transfer rate {FIG. 3 (b)}. These are referred to as third and fourth embodiments, respectively. The additional recording method and the error correction code adding method are the same as those in the first and second embodiments, respectively.

Further, in the equation (2), both M and N can be made variable, and the optimum combination can be selected according to the data transfer rate. This case is referred to as the fifth embodiment. The merit of the fifth embodiment is that the track length can be more finely adapted to the data transfer rate as compared with the first to fourth embodiments, so that the usage efficiency of the magnetic tape 11 is improved.

In order to make the explanation easy to understand, description will be given using the equation (1). For example, if the data transfer rate X of the signal sent is constant at 720 (Kbps) and the data recording rate Y when all 1 tracks are used is 1000 (Kbps), N is fixed at 10. Is M = 8 {8
00 (Kbps)} is the optimum value, and 80 on the magnetic tape 11
(Kbps) minutes are wasted every second, but for example N = 7, M
= 5, X = 714.3 (Kbps) from the equation (1), and the wasted area on the magnetic tape 11 is 6 per second.
(Kbps) or less, which is very small, and the capacity of the magnetic tape 11 can be effectively used. The additional recording method and the error correction code adding method in this case are the same as those in the first embodiment.

As a development example of the fifth embodiment, N and M
A sixth embodiment is conceivable in which at least one of the above is set to an optimum value for each recording track {FIG.
(C)｝. The additional recording method and the error correction code adding method of the sixth embodiment are the same as those of the second and fourth embodiments. The advantage of the sixth embodiment is that the data of the variable data transfer rate can be recorded on the magnetic tape 11 more efficiently than the second and fourth embodiments.

Next, the structure of the magnetic recording / reproducing apparatus in each of the above-mentioned embodiments will be described with reference to FIGS.
FIG. 5 shows the configuration of a magnetic recording / reproducing apparatus for recording data on the magnetic tape 11 by the method of FIGS.

In FIG. 5, reference numeral 21 in the drawing is a signal transmission device such as a satellite broadcast receiver or a network terminal, and the data transfer rate from the broadcasting station or the like for each program is constant or the maximum. A signal S whose data transfer rate is known in advance and which is continuous in time
11 is received, and this signal S11 is supplied to the data transfer rate detection device 22.

Further, the data transfer rate detecting device 22 is
The signal transfer rate of the signal S11 output from the signal transmission device 21 is detected, and the time required to record one track prior to recording is set as one cycle, and the signal S1
Divide 1 into blocks. Then, the signal S12 for one track is temporarily stored in the time axis conversion memory 23.

The signal S13 for one track stored in the time axis conversion memory 23 is supplied to the signal processing / encoding device 24. The signal processing / encoding device 24 adds an error correction signal or an address signal to the signal S13, performs interleaving, or the like,
It is converted into a format to be recorded on the magnetic tape 11. The signal S14 converted by the signal processing / encoding device 24 has an increased amount of information as compared with the signal S11 output from the signal transmission device 21. After that, the signal S converted by the signal processing / encoding device 24 is processed.
14 is supplied to the N / M designation device 25.

The N / M designating device 25 determines the number of blocks N and M based on the signal S14 output from the signal processing / encoding device 24 so as to comply with the equation (1) or the equation (2).

The signal S15 corresponding to the determined block numbers N and M is supplied to the modulation / electromagnetic conversion device 26. The modulation / electromagnetic conversion device 26 receives the supplied signal S
15 is modulated and amplified, and the signal S16 is modulated by the recording head 27.
To record the data on the magnetic tape 11.

That is, according to the first embodiment, the data transfer rate of a signal sent from the outside and the data recording rate on the magnetic recording / reproducing apparatus side are omitted without changing the tape speed of the magnetic tape 11. Since they can be matched, it is not necessary to change the rotation speed of the capstan for tape transport. Therefore, the rotation control of the capstan becomes easy, and the stable running of the magnetic tape 11 can be realized. Further, according to the first embodiment, the recording speed of the data on the device side can be substantially matched with the transfer speed of the signal sent from the outside. It is possible to realize stable running of the magnetic tape 11 without the need for repeated operations. Furthermore, according to this embodiment, the data transfer rate of the signal sent from the outside and the data recording rate on the magnetic recording / reproducing apparatus side can be substantially matched without changing the rotation speed of the rotary head. Therefore, the number of rotations of the rotary head at the time of recording / reproducing is always constant and good. Therefore, the state of the air film around the rotary head is stable, and thus the head touch of the rotary head on the magnetic tape 11 is stable.

Next, referring to FIG. 6, the structure of the magnetic recording / reproducing apparatus in the case of additionally recording new data on the magnetic tape 11 on which the data is already recorded in the fifth and sixth embodiments. Explain.

In FIG. 6, the same parts as in FIG. 5 is different from FIG. 5 in that the signal sending device 21 is replaced with a signal sending device 28 such as a hard disk drive device or a magneto-optical disk recording / reproducing device that can control sending / stopping of a signal by an external command. The points are different. A reproducing head 29 is attached to the magnetic tape 11 so as to precede the recording head 27 by at least one track on a rotary head drum (not shown) with a step. The reproducing signal S17 from the reproducing head 29 is stored in the memory. It is output to the N / M designation device 25 through the N / M determination device 31. Further, the signal transmission device 28, based on the signal from the N / M designation device 25,
The data sending speed, that is, the data transfer rate can be made variable. The magnetic tape 11 already has track 3
Data has already been recorded by a different method for each two.

Here, changing the number of blocks N or M means designating the data transfer rate of data to be additionally recorded on the magnetic recording / reproducing apparatus side. Therefore, the device on the data transfer side is limited to a device such as a hard disk drive device that can change the data transfer rate according to the request from the recording / reproducing device side.

That is, when the number of blocks N or M is constantly changing, the reproducing head 29 reproduces each recorded track 3
Before recording 2, the number N of each track written on the magnetic tape 11 and the number M of additionally recordable blocks are constantly monitored. In this case, the reproducing head 29 is the magnetic tape 1
The record information added to the predetermined position of the data recorded on the first unit is read. Then, the reproduction signal S17 corresponding to the record information read by the reproduction head 29 is
Once stored in the memory 30.

In the memory 30, when the data transfer rate of a signal sent from the outside is equal to the maximum recordable data recording rate of the magnetic recording / reproducing apparatus, data recording is performed for one track (for example, 10 blocks). Therefore, any data can be stored as long as it can store data for one track. Therefore, it is not necessary to use a large-capacity buffer memory as in the related art. The reproduction signal S17 stored in the memory 30 is supplied to the NM determining device 31 as a signal S18.

The N / M judging device 31 constantly judges the number of blocks N and M of the recorded track 32 from the signal S18 from the memory 30, and outputs the signal S1 corresponding to this judgment result.
9 is supplied to the N / M designation device 25. Therefore, N
In the M designation device 25, it is calculated whether the length of the track 33 (the hatched portion in the drawing) of the recorded track 32 should be additionally recorded and the end of the track 34 after the additional recording should be aligned. The number of blocks N and M of the track 33 to be additionally recorded is determined.

Then, the modulation / electromagnetic conversion device 26 is
Based on the signal S15 corresponding to the block numbers N and M determined by the M designation device 25, the additional recording data is modulated and amplified, and the recording head 27 is connected to the end of the recorded track 32 on the magnetic tape 11. To let As a result, the ends of the tracks 34 become uniform.

Here, the reproduction signal S17 from the reproduction head 29 is synchronized with the tape running speed, the rotation of the rotary head drum, the recording start point, etc. so that the track 33 is accurately connected to the end of the recorded track 32. It goes without saying that it is also used in a servo circuit (not shown) for controlling the. This servo circuit uses the conventional ATF (Automatic
ic Track Finding) This is the same as the control device such as a device.

That is, in the magnetic recording / reproducing apparatus shown in FIG. 6, the number of blocks N or M is variable according to the data transfer rate of the signal sent from the outside. Therefore, while the data transfer rate of the transmitted signal is temporarily reduced, it is possible to prevent a wasteful area such as not recording data or recording dummy data on the magnetic tape 11. Therefore, it is possible to prevent the tape utilization efficiency from being lowered.

[0051]

As described in detail above, according to the present invention,
It does not require a large-capacity buffer memory and can flexibly adapt the data recording rate to the data transfer rate without changing the tape speed or the number of revolutions of the rotating head, etc., and also provides stable tape running and head touch. In addition, it is possible to provide a magnetic recording / reproducing apparatus capable of maximizing the effective use of the tape.

[Brief description of drawings]

FIG. 1 is a diagram showing a first data recording method in an embodiment of a magnetic recording / reproducing apparatus according to the present invention, showing a state in which dummy data is written in a block in which no data is written.

FIG. 2 is a diagram showing a state in which a block of data in the embodiment is a non-recording portion.

FIG. 3 is a diagram showing an error correction code added when recording data on the magnetic tape according to the first embodiment.

FIG. 4 is a diagram showing a second recording method in the second to sixth embodiments of the present invention.

FIG. 5 is a block configuration diagram shown for explaining a configuration of a magnetic recording / reproducing apparatus in a first recording method.

FIG. 6 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to a second recording method.

[Explanation of symbols]

 11 ... Magnetic tape, 12 ... Track, 21 ... Signal sending device, 22 ... Data transfer rate detecting device, 23 ... Time axis conversion memory, 24 ... Signal processing / encoding device, 25 ... N / M designation device, 26 ... Modulation / Electromagnetic conversion device, 27 ... Recording head, 28 ... Signal sending device, 29 ... Reproducing head, 30 ... Memory, 31 ... NM judgment device, 32 ... Recorded track, 33 ... Track, 34 ... Track, 35 ... Error correction Code space, 36 ... Error correction code.

Claims (9)

[Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing data by helically scanning a magnetic tape using a rotary head, wherein a data transfer rate of a signal output from a signal supply unit per unit time Data transfer rate detecting means for detecting the data, the maximum recordable data recording rate of data in the device, and the track 1 to be recorded on the magnetic tape based on the data transfer rate detected by the data transfer rate detecting means. The block division number N and the block number calculation means for calculating the value of the data recording block number M of the block division number N, the block division number N and the block division number calculated by the block number calculation means Based on the value of the number M of data recording blocks in N, the rotary head for recording is A magnetic recording / reproducing apparatus comprising: a recording head control means for controlling writing of data to the magnetic tape. 2. The magnetic recording according to claim 1, wherein the signal supply source is either a receiving device for taking in a signal from a radio wave or a signal generating device for reproducing a signal from a recording medium. Playback device. 3. The block number calculating means, where X is the data transfer rate detected by the data transfer rate detecting means and Y is the maximum recordable data recording rate, X ≦ Y × M / N 2. The magnetic recording / reproducing apparatus according to claim 1, wherein M and N are obtained so as to satisfy the condition. 4. The block number calculation means adds the data amount added to the signal output from the signal supply source at the time of data recording to 1 / Z of the data amount of the data recording block.
2. The magnetic recording / reproducing apparatus according to claim 1, wherein M, N and Z are determined so as to satisfy X ≦ Y × {M × (1-1 / Z) / N}. 5. Further, at least one of the block division number N for one track and the data recording block number M of the block division number N is ended for each track or one program is started. To do 1
2. It can be changed for each recording period.
The magnetic recording and reproducing apparatus according to claim 1. 6. A reproducing rotary head attached to the magnetic tape so as to precede the recording rotary head by at least one track, and data of the magnetic tape read by the reproducing rotary head. 2. The magnetic recording / reproducing apparatus according to claim 1, further comprising a memory unit for storing the. 7. When additionally recording new data on the magnetic tape in which data has already been recorded in the M data recording blocks, the data of M blocks is temporarily read by the rotary head for reproduction. L is stored in the memory unit and is stored before or after the data of the M blocks.
7. The whole of one track as data of (M + L) blocks is overwritten on the magnetic tape in a state where new data of blocks (however, L ≦ N−M) is added. Magnetic recording / reproducing device. 8. When data is recorded on the magnetic tape, the value of the block division number N for one track, the value of the data recording block number M of the block division number N, 1 2. The magnetic recording medium according to claim 1, wherein information on the number of tracks in a recording period is recorded in at least one of a predetermined position in the track to be recorded and a memory unit mounted in a cassette containing the magnetic tape. Recording / playback device. 9. The magnetic tape is further configured such that at least one error correction code space is completed by data which is an integral multiple of the data recorded in one block divided into the N pieces. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording / reproducing apparatus is completed by data that is continuously recorded or reproduced.