JPH08273248A - Method for controlling magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To prevent the overwrite to a recorded track by recording a signal in the prescribed amount containing the information for stabilizing the running of magnetic tape at the time of reproduction, and recording, after that, a signal subjected to processing for the recorded time to the input signal. CONSTITUTION: When the recording operation is started, the control is started to make the running speed of the magnetic tape 510 to the running speed at the time of 10M mode, after the magnetic tape is once unwound so that the running of the magnetic tape 510 is stabilized by the time point 772 to start the recording of the signal for stabilizing the running of magnetic tape. The recording signal is not sent to the magnetic head till the time point 772 to start the recording of the signal stabilizing the running of magnetic tape. By advancing the magnetic tape in the prescribed amount without recording the signal to the specified track part after the effectively recorded track 721 in such a manner, the overwrite on the effectively recorded track is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing system for helically recording and reproducing a digital signal on a magnetic tape using a rotary magnetic head.

[0002]

2. Description of the Related Art As a digital VTR for recording / reproducing a digital signal, by changing the running speed of a magnetic tape in accordance with the transmission rate of a digital input signal while the rotation speed of a cylinder equipped with a magnetic head remains constant. There is a system for recording and reproducing signals. (Example: JP-A-1-
258255). The above-mentioned conventional example does not describe the processing of the joint portion when a signal is written on the same magnetic tape at the traveling speeds of different magnetic tapes.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to use a VTR having a plurality of running speeds of a magnetic tape at the time of recording / reproducing so as not to erase a signal required immediately before the recording on the magnetic tape. It is to obtain a normal reproduction signal from the first portion of the recorded signal at the change point of the magnetic tape running speed during recording and reproduction.

[0004]

In order to achieve the above object, the present invention starts a recording operation when starting recording on a magnetic tape using a VTR having a plurality of running speeds of the magnetic tape during recording and reproduction. After advancing the magnetic tape by a predetermined amount without starting recording from a point, a predetermined amount of a signal containing information for stabilizing the running of the magnetic tape at least during reproduction is recorded, and then a recording process for an input signal. The method for controlling a magnetic recording / reproducing apparatus is characterized by recording the signal obtained by

[0005]

According to the present invention, by using the VTR having a plurality of running speeds of the magnetic tape at the time of recording / reproducing by the above means, it is possible to perform recording on the magnetic tape without erasing a signal immediately before the recording. In addition, it is possible to obtain a normal reproduction signal from the first portion of the recorded signal at the change point of the magnetic tape running speed during reproduction.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an example of the configuration of a signal processing circuit for realizing an embodiment of the present invention. In FIG. 1, 110 is a signal input terminal for receiving a digital signal, and 100 is a signal transmission and an error during input is corrected. An error corrector, 200 is a recording signal system controller for detecting the transmission rate of the input signal received at the signal input terminal 110, determining the processing mode, and controlling the input bit rate converter 300, and 300 is the signal input terminal 110.
An input bit rate converter for temporarily storing the input signal received in step 400 and converting it to the processing rate of the recording signal processor 400;
Is a recording signal processor for performing signal processing such as addition of error correction code, transmission rate and processing mode information on the signal sent from the input bit rate converter 300, a magnetic tape 510 for storing the signal, and a cylinder 520 for storing the signal. 521,
522 is a recording / reproducing magnetic head having different azimuth angles, 523 and 524 are recording / reproducing magnetic heads having different azimuth angles, 600 is a running state of the magnetic tape 510, and a servo controller 610 for controlling the cylinder 520. Is a control head for recording / reproducing a control signal to / from the magnetic tape 510, which is used as a reference signal of the rotation phase of the cylinder 520, and 700 is the magnetic tape 5.
10, a reproduction signal processor that performs signal processing such as error correction on the reproduction signal read from 10 and detects information such as a transmission rate and a processing mode from the reproduction signal; 800 is a transmission rate sent from the reproduction signal processor 700; A reproduction signal system controller 900 for controlling the output bit rate converter 900 by using an internal frequency oscillator or the like according to information such as a processing mode.
Is an output bit rate converter for temporarily storing a signal input at the processing rate of the reproduction signal processor 700 and converting it to an output transmission rate, and 120 is a signal output for outputting the digital signal sent from the output bit rate converter 900 to the outside. It is a terminal. The operation of this embodiment will be described below.

FIG. 2 shows an example of the configuration of signals input to the signal input terminal 110. The input signal is divided into blocks of arbitrary length and input in the form shown in FIG. 21 is a signal (SOB) indicating the beginning of a block, 22 is a signal information section (ID) containing information such as the transmission rate of the signal, 23 is a signal data section, 24 is an error correction code section (Parity) for the ID 22 and the signal data 23. ) And 25 are signals (EOB) indicating the end of the block.

The input signal input to the signal input terminal 110 is sent to the error corrector 100. The error corrector 100 performs signal transmission processing on an input signal and correction processing of an error generated at the time of signal input, and sends the corrected signal to the recording signal system controller 200 and the input bit rate converter 300.
The recording signal system controller 200 detects the transmission rate from the ID or the like of the input signal and determines the processing mode. The recording signal system controller 200 sends recording signal information such as a transmission rate and a processing mode to the recording signal processor 400, sends a processing mode to the servo controller 600, and controls an input bit rate converter according to the transmission rate and the processing mode. The signal is sent to the input bit rate converter 300.

Here, the processing mode will be briefly described. In the present embodiment, as an example, the processing modes are the following three modes. The transmission rate of the input signal is 10 Mbps (b
20: ps: bits per second)
The processing mode for Mbps or lower is set to 20M mode,
Input signal transmission rate exceeds 5 Mbps and 10 Mbps
The processing mode when s or less is 10M mode, and the processing mode when the transmission rate of the input signal is 5 Mbps or less is 5M mode. For example, if the input signal transmission rate is 8
In the case of Mbps, the processing mode is 10M mode.

In this embodiment, a signal is recorded on the magnetic tape 510 by performing processing at a constant processing rate without changing the processing rate from the recording signal processor 400 to the reproduction signal processor 700 for each processing mode. The recording frequency and the number of rotations of the cylinder 520 are set to be constant, and the configuration from the recording signal processor 400 to the reproduction signal processor 700 is one system. In the recording system, the input bit rate converter 300 performs a process of converting signals of various transmission rates into a constant processing rate, and in the reproducing system, a process of converting signals of a constant processing rate into a transmission rate at the time of input. The output bit rate converter 900 performs this.

Next, the input bit rate converter 300 will be described, and the output bit rate converter 900 will be described later when the reproduction processing operation is described. FIG. 3 shows the relationship between the input signal and the output signal of the input bit rate converter 300 in each processing mode. In Figure 3, (input)
Is from the error corrector 100 to the input bit rate converter 300
, And (output 1) and (output 2) are signals that have been bit rate converted by the input bit rate converter 300. The signal shown at (output 1) in FIG. 3 is sent from the input bit rate converter 400 to the recording-system signal processor 400, and is recorded on the magnetic tape 510 by the magnetic head 521 or 523 after being processed at the time of recording. . The signal shown at (output 2) in FIG. 3 is the input bit rate converter 400.
Is sent to the recording-system signal processor 400, and a recording process is performed, and thereafter, the data is recorded on the magnetic tape 510 by the magnetic head 522 or 524.

The processing unit period used in FIG. 3 will now be described. In this embodiment, when recording a signal on the magnetic tape 510, a pair of magnetic heads (521 and 522,
Or, record simultaneously at 523 and 524). Therefore, the period from the start of recording (or reproduction) with two magnetic heads at a certain time to the start of recording (or reproduction) with the next set of magnetic heads is defined as a processing unit period. Processing mode is 20
In the M mode, recording is performed by two sets of magnetic heads, one set of magnetic heads (521 and 522) and the other set of magnetic heads (523 and 524) while the cylinder 520 makes one rotation. The processing unit period is a time period during which the cylinder 520 makes a half rotation. Where the cylinder 52
The time during which 0 rotates half way, that is, the processing unit period in the 20M mode is Tch. Further, in this embodiment, as an example of the processing mode, the processing mode (20M mode, 10M mode, 5M mode) is selected so that the ratio of the maximum input transmission rate in each processing mode is 4: 2: 1. When a signal with the highest input transmission rate in each processing mode is input, the ratio of time until a certain number of data is input is 1: 2: 4. Therefore, the processing unit period in the 10M mode is 2Tch which is twice that in the 20M mode, and the processing unit period in the 5M mode is 4Tch which is four times that in the 20M mode.

In (1) of FIG. 3, the transmission rate of the input signal is 2
It shows the case where the processing mode is 0 Mbps and the processing mode is 20 M.
The input signal is converted to a predetermined bit rate for each processing unit period Tch in the 20M mode and output. In (2) of FIG. 3, the transmission rate of the input signal is 10 Mbps and the processing mode is 1
The case of the 0M mode is shown, and the input signal is converted to a predetermined bit rate and output every 2Tch of the processing unit period of the 10M mode. In (3) of FIG. 3, the input signal transmission rate is 5
The case where the processing mode is 5M mode in Mbps is shown, and the input signal is converted to a predetermined bit rate and output every 4Tch of the processing unit period of the 5M mode. In this way, the input memory buffer 300 performs signal processing according to each processing mode, and outputs a signal to the recording signal processor 400 at a predetermined processing rate without changing the processing rate for each processing mode.

In the recording signal processor 400, the signal sent from the input bit rate converter 300 is divided into a certain data amount unit as a minimum synchronization unit at the time of reproduction,
The error correction code, the signal rate, and the signal identification information such as the processing mode are added to the signal of the fixed data amount unit, and the signals are combined into a sync block. The signals processed by the recording signal processor 400 are recorded / reproducing magnetic heads 521, 522, 5
23, 524. FIG. 4 is a diagram showing a configuration example of the sync block. In FIG. 4, 41 is a synchronization pattern section (SYNC), 42 is a signal information section (ID) including identification signals such as an input transmission rate and a processing mode sent from the recording signal system controller 200, 43 is a signal data section, Reference numeral 44 is an error correction signal section (Parity).

Signals output from the recording signal processor 400 are recorded / reproduced magnetic heads 521, 522, 523 mounted on a cylinder 520 which rotates at a constant rotation speed.
As shown in FIG. 5, the data is recorded on the magnetic tape 510 running at a predetermined speed according to the processing mode by 524. Figure 5
The structure of the tracks recorded on the magnetic tape 510 by the scanning of the recording / reproducing magnetic head in each processing mode is shown in FIG.
In FIG. 5, P1, P2, Q1, and Q2 indicate tracks recorded by scanning of the recording / reproducing magnetic heads 521, 522, 523, and 524, respectively.
The diagonal lines in 2, Q1, and Q2 are the magnetic heads 52 for recording and reproducing.
The state in which azimuth recording is performed by the azimuth angles given to 1, 522, 523, and 524 is shown.

In each processing mode, the signals sent to the recording / reproducing magnetic heads 521, 522, 523, 524 have a constant data rate and a constant data length as shown in (output 1) and (output 2) of FIG. However, every time the cylinder 520 makes a half rotation (Tch) in the 20M mode, every time the cylinder 520 makes one rotation (2Tch) in the 10M mode, the cylinder 520 makes two rotations (4Tc) in the 5M mode.
Each time h), a signal is sent. Since the rotation speed of the cylinder 520 does not change depending on the processing mode and is constant, two sets of magnetic heads (521, 522 and 52) are used in the 20M mode.
3, 524) are alternately used to record for each Tch, and 1
In the 0M mode, recording is performed every 2 Tch using only one set of magnetic heads (521 and 522 in FIG. 5), and in the 5M mode, only one set of magnetic heads (521 and 522 in FIG. 5) is used. Recording is performed every 4 Tch. Here, assuming that the traveling speed of the magnetic tape 510 in the 20M mode is V, the traveling speeds of the magnetic tape 510 in the 10M mode and the 5M mode are V / 2 and V /, respectively.
Control to 4. By controlling the running speed of the magnetic tape 510 by the servo controller 600 as described above, it is possible to use the magnetic tape 510 without waste in each processing mode without a gap between recording tracks as shown in FIG. .

At the same time that the signal subjected to the recording signal processing is recorded, the control signal serving as a reference for servo control of the cylinder 520 during reproduction is the control head 6.
The data is recorded on the magnetic tape 510 via 10. As an example, in the present embodiment, the number of revolutions of the cylinder 520 is constant regardless of each processing mode, so that the control signal also records a signal of a constant cycle.

Next, the reproducing operation will be described. The signal recorded on the magnetic tape 510 is read by the recording / reproducing magnetic heads 521, 522, 523, and 524 attached to the cylinder 520 that rotates at a constant rotation speed, and sent to the reproduction signal processor 700. Thus, the cylinder 520
The bit rate of the signal sent to the reproduction signal processor 700 can be made constant regardless of the processing mode and the like by reading the signal while keeping the rotation speed of the signal constant. In the reproduced signal processor 700, first, an error correction process or the like is performed on the reproduced signal to separate it into a signal data portion (43 in FIG. 4) and an ID (42 in FIG. 4) including a transmission rate and a processing mode. Next, the separated signal data portion is sent to the output bit rate converter 900 at a predetermined bit rate, information such as a processing mode, a transmission rate, and the number of valid data is detected from the ID, and the servo controller 600 and the reproduction signal system control are performed. Send to container 800. The servo controller 600 controls the traveling speed of the magnetic tape 510 to a speed corresponding to each processing mode based on the processing mode information sent from the reproduction signal processor 700, and uses the control signal obtained from the control head 610 to control the cylinder 520. Servo control. Further, in the reproduction signal system controller 800 having a built-in frequency oscillator, the reproduction signal processor 7
00, a memory control signal is sent to the output bit rate converter 900 according to the information such as the processing mode and the transmission rate sent from 00.

Next, the operation of the output bit rate converter 900 will be described. FIG. 6 shows the relationship between the input signal and the output signal of the output bit rate converter 900 in each processing mode. 6, (input 1) indicates a signal read from the magnetic tape 510 by the magnetic head 521 or 523 and processed by the reproduction signal processor 700, and (input 2) indicates from the magnetic tape 510 by the magnetic head 522 or 524. The signal read out and processed by the reproduction signal processor 700 is shown, and (output) shows the signal output after bit rate conversion by the output bit rate converter 900.

FIG. 6A shows the case where a signal obtained by recording an input signal of 20 Mbps in the 20 M mode is reproduced, and the signal sent from the reproduction signal processor 700 at a predetermined bit rate is a processing unit period of the 20 M mode. Each Tch is converted into the transmission rate at the time of input and output. 6 (2) is 1
A case of reproducing a signal in which an input signal of 0 Mbps is recorded in 10M mode is shown, and the signal sent from the reproduction signal processor 700 at a predetermined bit rate is converted into a transmission rate at the time of input in every processing unit period 2Tch of 10M mode. Is output. (3) of FIG. 6 shows a case where a signal obtained by recording an input signal of 5 Mbps in the 5 M mode is reproduced, and the signal transmitted from the reproduction signal processor 700 at a predetermined bit rate is 1
It is converted into the transmission rate at the time of input every 2Tch of the processing unit period of the 0M mode and is output.

In the case of a digital VTR for recording while changing the running speed of the magnetic tape according to the transmission rate of the input signal as described above, the following problems occur at the changing point of the running speed of the magnetic tape, that is, the changing point of the processing mode. Occurs. For example, when recording in a different processing mode from the position next to a recording track recorded in a certain processing mode, the immediately preceding valid recorded track is overwritten, or the running speed of the magnetic tape 510 at the change point of the processing mode at the time of reproduction. There is a possibility that a normal reproduction signal cannot be obtained until is stable.

FIG. 7A shows an example of the above problem. Figure 7
In (1), 710 and 711 denote recording tracks recorded in the 20M mode, and 712, 713, 714,
Reference numerals 715, 716, and 717 respectively indicate recording tracks recorded in the 10M mode, and reference numerals 791 and 792 respectively indicate inclinations of the recording tracks in the 20M mode and 10M mode with respect to the running direction of the magnetic tape 510.
Indicates the starting point of the recording operation and the signal recording in the 10M mode.

As shown in FIG. 7A, the processing mode is 20
When recording in the 10M mode from the next portion (781 in FIG. 7 (1)) of the recording track 711 recorded in the M mode, the tape running speed is V in the 20M mode, but V / 2 in the 10M mode. Therefore, the inclination 792 of the recording track in the 10M mode is smaller than the inclination 791 of the recording track in the 20M mode. Therefore, the recording track 7 recorded in the immediately preceding 20M mode
A part of 11 is overwritten with a signal to be recorded in the 10M mode (712 in FIG. 7 (1)). In this way, when recording is started in the processing mode of the tape traveling speed slower than the tape traveling speed of the processing mode recorded immediately before, a new signal is overwritten on a part of the recording track immediately before.

When reproducing from the recording track 712 recorded in the 10M mode, the running speed V of the magnetic tape 510 in the immediately preceding 20M mode or the stopped state is set to 1
It is conceivable that the recording track may not be accurately traced until the traveling speed V / 2 of the 0M mode magnetic tape 510 stabilizes. Therefore, the recorded data cannot be obtained until the tape running is stabilized, and normal reproduction cannot be performed.

According to the present invention, recording is not started immediately after the recording track but is started from a position advanced by a predetermined number of tracks so that a newly recorded recording track does not overwrite a valid recorded track. To do. Further, a magnetic tape running stabilization signal is recorded on a predetermined number of tracks after the start of recording, and then a signal obtained by performing a recording process on the input signal is recorded. Here, the magnetic tape running stabilization signal is a signal including at least processing mode information in the ID (42 in FIG. 4) in the sync block shown in FIG.
As a result, even at the change point of the reproduction processing mode, the valid data is reproduced after the tape running is stabilized, so that the effective data is not lost at the change point of the processing mode.

FIG. 7B shows the recording tracks at the processing mode changing points in this embodiment. In FIG. 7 (2),
720 and 721 are effective recorded tracks recorded in the 20M mode, and 722 and 723 are formed by advancing the magnetic tape by a predetermined number of tracks without recording a signal on the magnetic tape at the start of recording to prevent overwriting. Invalid part, 724, 725, 726, 727 is 10M each
7 shows the recording track for stabilizing the magnetic tape running in the mode.
Reference numerals 28 and 729 denote recording tracks on which the input signals are processed and recorded at the time of recording in the 10M mode, 771 indicates a recording operation start point in the 10M mode, and 772 indicates 10M.
The recording start point of the signal for stabilizing the magnetic tape running in the mode is shown, and the reference numeral 773 shows the recording start point of the signal obtained by processing the input signal during the recording in the 10M mode. Here, the magnetic tape running stabilization signal is the ID in the sync block shown in FIG.
(42 in FIG. 4) is a signal including at least processing mode information.

First, the recording process will be described. When the recording operation is started, the magnetic tape 510 is once rewound so that the traveling of the magnetic tape 510 is stabilized by the recording start point 772 of the magnetic tape traveling stabilization signal, and then the traveling speed of the magnetic tape 510 is in the 10M mode. Traveling speed V /
Start controlling to 2. The recording signal is not sent to the magnetic head until the recording start point 772 of the magnetic tape running stabilization signal. Thus, by advancing the magnetic tape by a predetermined amount without recording a signal on a predetermined track after the effective recorded track 721, it is possible to prevent overwriting on the effective recorded track. Here, the predetermined number of tracks means at least FIG.
The number of tracks is equal to or larger than the number of recording tracks (710, 711) to be overwritten, which is shown as an example in the case where the overwrite protection process is not performed in (1). In the present embodiment, as an example of the predetermined number of tracks, as shown in FIG.
The two tracks of No. 723 and 723 were set as the predetermined number of tracks. In this way, by making the predetermined number of tracks constant regardless of the processing mode before and after the start of recording, the processing mode detection processing immediately before the start of recording can be omitted.

Further, in the present invention, a predetermined number of tracks after the recording start point 772 of the magnetic tape running stabilization signal (see FIG. 7).
The magnetic tape running stabilization signal is recorded in 724, 725, 726, 727 in (2) and then (77 in FIG. 7 (2)).
In 3), the signal obtained by performing the recording process on the input signal is recorded (728 and 729 in FIG. 7B). Here, in this embodiment, as an example of the magnetic tape running stabilizing track,
4 tracks (724, 725, 72 in FIG. 7 (2))
6, 727), but this number is determined by the time it takes for the tape run to stabilize in the new process mode when the process mode changes. Therefore, the magnetic tape running stabilizing track is recorded such that the time for scanning the magnetic tape running stabilizing track is at least the time required for stabilizing the tape running. In the example of FIG. 7, the number is sufficient to stabilize the running of the magnetic tape 510 from the tape running speed V in the 20M mode to the running speed V / 2 in the 10M mode. By recording the magnetic tape running stabilizing track at the beginning of the recording track in this way, it becomes possible to obtain a stable reproduction signal from the tracks 728 and 729 during reproduction, as described below.

Next, the reproducing operation will be described. Figure 7
Consider the case of reproducing the portion recorded in the 10M mode in (2). First, 20 before the recording track 720
It is assumed that the reproduction starts from the place recorded in the M mode. 20
When reproducing in the M mode, the magnetic tape 510 runs at the running speed V in the 20M mode. After that, the magnetic head scans the recording track 724 on which the travel stabilization signal is recorded, and reads a part of the sync block written on the recording track 724. The read sync block is sent to the reproduction signal processor 700, and the processing mode (10M mode) included in the ID in the sync block is detected. The detected processing mode (10M mode) is sent to the servo controller 600, and the magnetic tape 510 is controlled to the traveling speed V / 2 in the 10M mode. The running of the magnetic tape 510 is stable until the magnetic head scans the recording track 727, and the locus of the magnetic head scanning the recording track 728 is the same as the scanning locus of the magnetic head during recording. Therefore,
A normal reproduction signal can be obtained from the first recording track 728 in which the signal obtained by performing the recording process on the input signal is recorded in the 10M mode.

In the part described above, the determination of the recording mode is obtained from the reproduction data of the travel stabilization signal. But,
The determination of the recording mode is not limited to this method. For example, the same determination can be performed using a control signal. That is, as described above, the control signal is a signal used as a reference signal of the rotation phase of the cylinder 520 during reproduction, and the rotation speed of the cylinder 520 is constant during recording, so the cycle of the control signal is also constant. However, since the running speed of the magnetic tape 510 is changed depending on the recording mode, the recording pattern of the control signal recorded on the magnetic tape 510 is different. By utilizing this, it is possible to determine the recording mode.

The reproducing operation will be described below with reference to FIGS. 7 and 8. Consider the case of reproducing a portion recorded in the 10M mode in FIG. 7 (2). FIG. 8 shows a control signal waveform reproduced at that time. In FIG. 8, 77
2, 773 indicate the same tape positions as 772, 773 in FIG. 7 (2). First, 20 before the recording track 720
It is assumed that the reproduction starts from the place recorded in the M mode. 20
When reproducing in the M mode, the magnetic tape 510 runs at the running speed V in the 20M mode. Then, the recording track 724 recorded in the 10M mode is scanned. 77 in FIG.
At the time of 2, playback is still in 20M mode and 10M
When the control signal recorded in the mode is reproduced, the cycle of the control signal obtained is halved because the tape speed is twice that in the original reproduction mode. The reproduced control signal is sent to the servo controller 600,
The magnetic tape 510 is controlled to the running speed V / 2 in the 10M mode by detecting the difference in the cycle. Magnetic tape 51
The running of 0 is stabilized by the time the magnetic head scans the recording track 727, that is, by 773 in FIG. 8, and the locus of the magnetic head scanning the recording track 728 is the same as the scanning locus of the magnetic head during recording. . Therefore, a normal reproduction signal can be obtained from the first recording track 728 in which the signal obtained by performing the recording process on the input signal is recorded in the 10M mode. According to this method, it is not necessary to record the above-described running stabilization signal on the recording stabilization track at the time of recording, which is effective in suppressing the scale of the signal processing circuit for recording.

Further, instead of using only one of the above-mentioned two methods, both of the two methods may be used. As a result, even when the traveling stabilization signal cannot be reproduced due to clogging of the head or the like, the mode determination can be reliably performed from the control signal.

As described above, according to the present invention, a VTR having a plurality of running speeds of the magnetic tape during signal recording / reproduction.
It is possible to obtain a good reproduction signal even when reproducing a place where the running speed of the magnetic tape changes by using.

[0035]

As described above, according to the present invention, no signal is recorded for a predetermined track from the position where the magnetic head is scanning when the recording operation is started, and at least the recording mode is executed for the next predetermined track. By recording a signal including the input transmission rate and the input signal after that, it is possible to prevent overwriting on a valid recorded track, and to reliably reproduce from the first part of the recorded input signal. It is possible to do so, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a block unit of a signal input to a signal storage and processing device.

FIG. 3 is a diagram showing a bit rate conversion process during recording.

FIG. 4 is a diagram showing a configuration example of a sync block which is a minimum unit when recording a signal on a magnetic tape.

FIG. 5 is a diagram showing a configuration example of tracks recorded on a magnetic tape by scanning of a recording / reproducing magnetic head in each processing mode.

FIG. 6 is a diagram showing a bit rate conversion process during reproduction.

FIG. 7 is a diagram illustrating a process at the start of recording.

FIG. 8 is a signal waveform diagram of a reproduction control signal.

[Explanation of symbols]

100 ... Error corrector 110 ... Digital signal input terminal 120 ... Digital signal output terminal 200 ... Recording system controller 300 ... Input bit rate converter 400 ... Recording signal processing 510 ... Magnetic tape 520 ... Cylinder 521, 522, 523, 524 ... Recording / reproducing magnetic head 600 ... Servo controller 610 ... Control head 700 ... Reproduction signal processor 800 ... Reproduction signal system controller 900 ... Output bit rate converter

Claims (1)

[Claims] 1. A magnetic recording / reproducing apparatus having a plurality of traveling speeds of a magnetic tape when helically recording and reproducing a signal on a magnetic tape by using a rotary magnetic head, wherein the traveling of the magnetic tape is determined by information on the traveling speed of the magnetic tape. A control means, a means for recording a servo reference signal indicating the rotation phase of the cylinder, and a means for recording a signal containing information on the traveling speed of the magnetic tape on the magnetic tape, The magnetic tape is advanced by a predetermined amount from the recording operation starting point by the means for controlling the running of the magnetic tape, and then a predetermined amount of a signal containing at least information on the running speed of the magnetic tape is recorded by the means for recording a signal relating to the running speed. After that, the signal processed by the input signal is recorded, and the signal is reproduced. Information about the travel speed of the flop, the control method of a magnetic recording and reproducing apparatus characterized by reproducing servos to determine the recording mode using at least one of the reproduced servo reference signal.