JPS634256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tracking preset correction circuit, and particularly to a helical scan type magnetic recording/reproducing device capable of selectively recording/reproducing in either standard mode or other mode. A tracking preset correction circuit is provided that allows mechanical and electrical adjustment of the control head, which is required in advance for optimal tracking and compatible playback, to be performed without the operator having to move the tracking volume, with a small number of adjustment operations. The purpose is to provide.

In recent years, home-use helical scan type magnetic recording and reproducing devices have achieved even higher recording and reproducing densities due to improved magnetic tapes, higher sensitivity of rotating heads, etc. By reducing the tape speed, track pitch, etc. to 1/3 of the conventional level without changing the number of signal fields, it is now possible to record and reproduce magnetic tape in a maximum of 6 hours, whereas previously it was possible to record and reproduce a maximum of 2 hours. The device is now being commercialized. The above 1/3 mode allows up to 6 hours of recording and playback, and the same tape speed and track pitch as before for up to 2 hours.
In a magnetic recording and reproducing device that selectively performs time recording and reproduction in the standard mode, if the 1/3 mode is designed to share the rotary head used in the standard mode, the image quality will normally be that of the 1/3 mode. In order to prevent so-called overwriting, the track width of the rotating head is set close to the width of the track formed in the 1/3 mode. Therefore, when recording in 1/3 mode using such a rotary head, no guard band is formed, but when recording in standard mode, the recording track pattern becomes as shown in Figure 1, for example. track width
Tracks of 19.3 μm are formed at a period of 58 μm, forming a guard band.

This guard band may deteriorate the playback image quality in standard mode, or when special playback is performed at a tape speed different from the recording speed, noise may be generated when crossing the guard band, and in severe cases, it may not be practical as a special playback image. is not obtained. Therefore, in the past, this phenomenon was prevented and standard mode and 1/1
In order to be able to form an optimal track pattern in any of the three modes, there was a magnetic recording/reproducing device that used a dedicated rotary head for each mode.
For example, in a magnetic recording/reproducing device that uses a rotary head with a track width of 58 μm shown as A in FIG. 2 for standard mode recording and playback, a track width of 19.3 μm shown as B in the figure for 1/3 mode recording and playback is used. A rotating head is used. In addition, in a two-head magnetic recording/reproducing device, the standard mode rotary heads A are mounted on the rotating drum at positions facing each other by 180 degrees as shown by A ₁ and A ₂ in FIG. As shown by B ₁ and B ₂ in the same figure, the rotary heads B are mounted at positions shifted, for example, by 70 degrees from A ₁ and A ₂ with respect to the rotational direction of the rotary drum, and facing each other by 180 degrees. (Therefore, in the device shown in the third figure, a total of four rotating heads are provided, and A ₁ and A ₂ , B ₁ and B ₂
have gaps with different azimuth angles. ).

By the way, when a helical scan type magnetic recording/reproducing device performs compatible playback of a magnetic tape recorded with another magnetic recording/reproducing device, optimal tracking can be performed without the user having to operate the tracking volume of the magnetic recording/reproducing device. As shown in FIG. 4, when the rotary head (not shown) is located at the exit (terminus) 2 of the video track, the position of the fixed control head 3 which records the control pulse at that time and at that time. It is well known that the distance in the longitudinal direction of the magnetic tape 1 (hereinafter referred to as the "X value") between the magnetic tape 1 and the rotating head position 2 is determined by standards. In order to obtain this standardized X value, conventionally, the control head 3 is set in advance at a position near the X value, and in this state the FM signal is recorded on the magnetic tape 1 by the rotating head, and the control pulse is recorded by the control head. After that, the same recorded magnetic tape 1 is played back by the same magnetic recording/playback device (this is called "self-recording/playback"), and the reproduced FM signal level is maximized, for example, in the capstan servo circuit. After adjusting the time constant of the monostable multivibrator (hereinafter referred to as "monomulti") in the reference signal generation circuit section of The position of the control head 3 was adjusted so that the level of the reproduced FM signal would be maximized.

However, in a magnetic recording/reproducing device that selectively operates between the standard mode and 1/3 mode using rotary heads dedicated to each mode, the control head 3
Since there is a single rotary head and a rotary head is provided exclusively for each mode, the X value must be satisfied in both the standard mode and 1/3 mode. That is, variations in the tape running system between the standard mode and 1/3 mode, variations in the position adjustment of the control head 3, and the relative relationship between the standard mode rotary head A and the 1/3 mode rotary head B shown in FIG. Height variation P
However, if the X value is adjusted with the control head 3 in the standard mode, the X value will be different in the 1/3 mode, which will cause problems when tapes are interchanged. Furthermore, since providing dedicated control heads for the standard mode and 1/3 mode would increase costs, a single control head was used. Therefore, in the magnetic recording/reproducing device described above, the X value is adjusted by mechanically adjusting the position of the control head, but in 1/3 mode, mechanical position adjustment of the control head is not possible. The deviation from the X value in the 1/3 mode of the control head was electrically corrected to match the X value on the magnetic tape.

The conventional X value adjustment in a magnetic recording/reproducing apparatus which selectively performs recording/reproduction in a desired mode using the rotary head dedicated to the standard mode and the rotary head dedicated to the 1/3 mode will be further explained with reference to the circuit diagram shown in FIG. First, the control head 4 is installed at a position near the X value in the standard mode, and the rotary head records a frequency-modulated video signal and the control head 4 records control pulses. That is, during this recording, the video signal to be recorded is passed through the input terminal 5, the synchronization signal separation circuit 6, and the low-pass filter 7.
8), which is then converted into a pulse with a constant pulse width that is phase synchronized with the vertical synchronization signal. During recording, this pulse is supplied to the monomulti 10, the contact 2H of the switch 12, and the monomulti 20 through the switch 9 connected to the contact R. The changeover switch 12 is connected to the contact 2H in the standard mode and to the contact 6H in the 1/3 mode (the same applies to the changeover switch 41 described later), so it is connected to the contact 2H here. Therefore, the output pulse of the monomulti 8 is supplied to the monomulti 13 via the changeover switches 9 and 12, respectively.
After being converted into a pulse with a predetermined pulse width and a two-field cycle (however, one track records one field of video signal), the selector switch 14 (connected to contact R) is activated. Then, the control head 4 records the information on the longitudinal end of a magnetic tape (not shown).

On the other hand, the rotary head for standard mode (for example,
A ₁ , A ₂ ) are rotated by a drum motor 15 and record frequency-modulated video signals, and the rotation of the drum motor 15 is detected by a known arrangement using a drum pick-up head 16 or the like. flipflop 1
7. A rectangular wave with a two-field period (for example, 30 Hz) is taken out from the flip-flop 17, converted into a trapezoidal wave by a trapezoidal wave generating circuit 18, and then supplied to a sampling and holding circuit 19. The sampling and holding circuit 19 is also supplied with a sampling pulse of two field periods delayed by a certain period of time from the vertical synchronizing signal that has entered through the monomultis 20 and 21, respectively, and is used to sample and hold the slope part of the trapezoidal wave. Let's do it. The output voltage of the sampling hold circuit 19 is applied to the drum motor 15 through a motor drive amplifier 22.
is applied to control its rotation at a constant level.

On the other hand, the rotation of the capstan motor 23 that rotates the capstan at a constant speed is detected by a known configuration including a capstan pickup head 24, etc., and a signal with a frequency corresponding to the rotation is sent to an amplifier 25, a frequency divider 26, The signal is supplied to a sampling hold circuit 29 through a changeover switch 27 and a sampling pulse generation circuit 28, respectively. On the other hand, a 2-field period pulse (for example, a symmetrical square wave) is extracted from the countdown circuit 31 that counts down the output of the crystal oscillator 30, and the width is adjusted by the next-stage monomulti 32, and the position is further adjusted by the monomulti 33. The signal is made to have an opposite phase by the monomulti 34 and converted into a trapezoidal wave by the trapezoidal wave generating circuit 35. This trapezoidal wave is the sampling hold circuit 2
9, where its slope portion is sampled and held, and then applied to the capstan motor 23 through a motor drive amplifier 36 to control its rotation at a constant level.

Next, the FM video signal and control pulses recorded on the magnetic tape are reproduced in the standard mode while the position of the control head 4 remains unchanged. Thereby, the control pulse reproduced by the control head 4 is supplied to the sampling pulse generation circuit 28 through the amplifier 38 and the changeover switch 41 connected to the contact 2H. On the other hand, the output pulse of the countdown circuit 31 is supplied to the sampling hold circuit 29 via the monomulti 32, 33, 34 and the trapezoidal wave generating circuit 35, and is sampled here in phase synchronization with the reproduction control pulse from the sampling pulse generating circuit 28. Sampling and holding is performed by pulse. The output voltage of this sampling hold circuit 29 is applied to the capstan motor 23 via a motor drive amplifier 36 to control its rotation. Note that at this time, the drum servo system performs the same operation as during recording.

Through the self-recording and reproducing described above, the time constant of the monomulti 32 is variably adjusted (tracking preset adjustment) so that the reproduced FM video signal level is maximized. Note that 37 is a tracking volume for adjusting the time constant of the monomulti 33 and is for exclusive use by the user, so its slider is fixed at the midpoint position and is not used when adjusting the tracking preset at the factory.

Next, as a second adjustment procedure, play the standard tape in the standard mode using the magnetic recording and reproducing device in the above state, and adjust the position of the control head 4 so that the level of the FM video signal played from the standard tape is maximized. be adjusted mechanically. This completes the X value adjustment in the standard mode of the magnetic recording/reproducing device.

Next, as the third adjustment step, play a standard tape in 1/3 mode and adjust the playback FM from this standard tape.
Mono multi 3 to maximize the video signal level
Adjust the time constants of 9 and 40, respectively. That is,
The above X value adjustment is for the standard mode, and since the position of control head 4 cannot be moved due to the completion of the above X value adjustment, this is the X value adjustment for the 1/3 mode.
This controls the amount of delay of the reproduction control pulse so that the desired value can be obtained. Here, the time constants of the monomultis 39 and 40 differ depending on the magnetic recording/reproducing apparatus. In addition, the variable range of the delay amount of this reproduction control pulse is such that the period of the reproduction control pulse is, for example, 33.3 msec (30 Hz), so if it is 33.3 msec or more, any variation in the mechanical X value can be electrically absorbed. be able to. Therefore,
In order to have a variable delay amount range of 33.3 msec or more, two monomultis are required as shown at 39 and 40. Because one monomulti is 33.3m.
This is because if an attempt is made to obtain a delay amount of sec or more, the 30Hz input reproduction control pulse will be divided in half and become 15Hz. This makes the correct X
The X value can be adjusted by electrical circuit adjustment in order to properly play back a standard tape recorded in 1/3 mode in 1/3 mode.

However, even when self-recording and playing back in 1/3 mode,
Control pulses must be recorded on the magnetic tape with standardized X values. Therefore, as a fourth adjustment procedure, the delay amount of the control pulse, which is conventionally recorded by self-recording and reproducing in 1/3 mode, is variably controlled by monomultis 10 and 11, so that the X value matches on the magnetic tape. Make it. The phase adjustment of the recording control pulse in this 1/3 mode satisfies the normal X value when the FM video signal level during playback is at its maximum as a result of the third adjustment above, so the playback FM video signal level is The time constants of the monomultis 10 and 11 are adjusted so as to be maximized.

During playback in this 1/3 mode, the playback control pulse from the control head 4 becomes as shown in Fig. 6A, and the output signal waveforms of the mono multi 39 and 40 become as shown in Fig. The pulse generating circuit 28 outputs a sampling pulse shown in FIG. Also, Figure 6E,
F, G, H and I indicate the output signal waveforms of the countdown circuit 31, monomulti 32, 33, 34 and trapezoidal wave generation circuit 35 in FIG. 5, respectively.

As described above, the conventional tracking preset correction requires four adjustment procedures and has the disadvantage that the adjustment is extremely complicated.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described below with reference to FIGS. 7, 8A to 8, etc.

FIG. 7 shows a circuit system diagram of an embodiment of the tracking preset correction circuit according to the present invention. In the figure, the same components as in FIG. 5 are given the same numbers. Further, since the operation of the drum servo system is the same as the conventional one, its explanation will be omitted. The present invention enables fewer operations for tracking preset correction than in the past. When the present invention is applied to a magnetic recording and reproducing device that selectively performs recording and reproducing in a desired mode using a rotary head dedicated to the standard mode and a rotary head dedicated to the 1/3 mode, the first adjustment procedure is to perform self-recording and reproducing in the standard mode. The time constant (delay amount) of the monomulti 44, which is the first pulse delay circuit, is adjusted so that the reproduced FM video signal level is maximized.
Set variably. That is, first in standard mode
While the FM video signal is recorded on the magnetic tape by a rotating head, a pulse with a two-field period synchronized with the vertical synchronization signal separated and taken out according to the video signal to be recorded is generated, and this pulse is
Switches 9, 12 and monomulti 4 shown in the figure
4, 33, 34, are supplied to the sampling hold circuit 29 through the trapezoidal wave generating circuit 35, where the sampling is held by a sampling pulse of 2 field periods synchronized with the rotation of the capstan motor 24 from the sampling pulse generating circuit 28. Then, by applying the output voltage to the capstan motor 23 via the motor drive amplifier 36, the capstan motor 23 is rotated at a constant speed.

At the same time, two
A field period pulse is applied to the monomulti 13, converted into a pulse with a predetermined pulse width and a repetition frequency of 30 Hz, and recorded by the control head 4 as a control pulse. At this time, the control head 4 is in the standard mode as before.
It is fixed at a position near the value. Next, this recorded magnetic tape is reproduced in standard mode using the same magnetic recording and reproducing device. As a result, the control pulse regenerated by the control head 4 is supplied to the sampling hold circuit 29 through the amplifier 38, the changeover switch 27, and the sampling pulse generation circuit 28, where it is output from the crystal oscillation circuit 30 and counted down by the countdown circuit 31. Furthermore, the trapezoidal waves inputted through the changeover switches 9 and 12, the monomultis 44, 33, and 34, and the trapezoidal wave generation circuit 35 are sampled and held.

The output voltage of the sampling and holding circuit 29 is applied to the capstan motor 23 via a motor drive amplifier 36 to control its rotation. Thereby, the rotation of the capstan motor 23 is controlled in synchronization with the reproduction control pulse. Here, the tracking preset is an adjustment so that the phase relationship between the drum pulse output from the flip-flop 17 and the playback control pulse is the same as that during recording, and at this time, the playback FM video signal level is set to the maximum level. becomes. Therefore, tracking preset correction can be performed by varying the time constant of the monomulti 44 so that the reproduced FM video signal level is maximized.

The above standard mode tracking preset adjustment was performed with the control head 4 near its normal position, so it is necessary to mechanically adjust the position of the control head 4 so that it satisfies the normal X value. There is. Therefore, as described above, the standard tape in the standard mode is played back in the standard mode, and the position of the control head 4 is mechanically adjusted so that the reproduced FM video signal level is maximized. By performing the above first and second adjustment procedures, the control head 4 is fixed at a position that satisfies the regular X value, and the standard mode tracking preset correction is completed, but these adjustment procedures are It is performed using the same circuit and the same operation.

Next, the circuit of the present invention performs 1/3 mode tracking preset correction while playing back the 1/3 mode standard tape. 1/3 mode standard tape is a tape on which an ideal state has been magnetically recorded in advance with the regular X value of 1/3 mode, and the video signal is frequency modulated and recorded on the video track, and
Control pulses are recorded on the control track.

The above standard tape recorded in 1/3 mode is
The data is reproduced by a magnetic recording/reproducing device that has completed standard mode tracking preset correction. As a result, the control pulse as shown in FIG. 8A reproduced by the 1/3 mode dedicated rotary head is
In the figure, the signal passes through an amplifier 38, a changeover switch 27, and a sampling pulse generation circuit 28, respectively, and is converted into a sampling pulse as shown in FIG. 8B, and is supplied to a sampling hold circuit 29. On the other hand, the seventh
The pulse as shown in FIG. 8C extracted by the countdown circuit 31 shown in the figure is commonly used as a reference signal for the drum servo system and the capstan servo system, and is passed through the changeover switch 9 to the second signal along with the monomulti 43, which will be described later. The pulse is applied to the monomulti 42 constituting the pulse delay circuit of FIG. 8, where the width is adjusted to form the pulse shown in FIG. It is considered to be a pulse. The output pulse of the monomulti 43 is applied to the monomulti 44 via the changeover switch 12, where it is converted into the pulse shown in FIG. 8F, and then applied to the monomulti 33, which is triggered at its fall. As a result, Monomulti 33
The pulse shown in FIG. 8G is extracted from the pulse generator, and is made into the pulse shown in FIG. . This trapezoidal wave is supplied to a sampling and holding circuit 29, where a substantially central portion of its slope is sampled and held by the sampling pulse shown in FIG. 8B. This sampling and hold voltage is applied to the capstan motor 23 via a motor drive amplifier 36. This allows the magnetic tape to run at a constant tape speed that is 1/3 slower than in standard mode.

During standard tape playback in this 1/3 mode,
The time constants of the monomultis 42 and 43 are variably controlled so that the reproduced FM video signal level is maximized. With this adjustment, the reproduction control pulse for the drum pulse in the 1/3 mode is the same as when it is reproduced from the control head 4 at the normal X value in the 1/3 mode. With the above steps, tracking preset correction by the circuit of the present invention is completed.
That is, the circuit of the present invention does not require adjustment to maximize the level of the reproduced FM video signal by self-recording and reproducing in 1/3 mode, which was necessary in the conventional circuit.

This will be explained in more detail. In the conventional circuit shown in Fig. 5, when correcting the tracking preset in 1/3 mode, if the position of the control head deviates toward the drum by ΔX (ΔTmsec) from the normal X value as shown by 3' in Fig. 4. In order to electrically correct this X value deviation ΔX, the total delay amount A due to monomultis 10 and 11 is
(msec) is recorded as 33.3 - ΔT (here, 33.3 msec is the period of the control pulse), and during playback, the tracking preset is adjusted to the deviation of ΔX in the position of the control head 3'. The total delay amount B due to the monomulti 39 and 40 is
The relationship A+B=33.3 (mseo) was established, where (msec) was set as ΔT. For this reason, 1/
Three-mode tracking preset correction requires the above-mentioned two adjustment procedures, the third and fourth.

On the other hand, according to the circuit of the present invention, the control pulse in the 1/3 mode is delayed by the monomultis 42 and 43 only during recording (as shown in FIG. 4, the control head 3' is shifted toward the ΔTmse drum side). It is configured to be used as a comparison signal for the capstan servo circuit without being delayed during playback, and is used as a comparison signal for the capstan servo circuit. The delay amount of the mono multi 44 that delays the signal (this is also the reference signal for the drum servo system) is adjusted in advance so that the playback FM video signal level is maximum when self-recording and playback is performed in standard mode, and the delay amount is adjusted to 1/ When playing in 3 modes, this mono multi 4
Since the reference signal is delayed by adding the delay amount caused by the mono multi 42 and 43 to the delay amount of 4, the total delay amount of the mono multi 42 and 43 is No matter what the value, the phase of the playback control pulse with respect to the drum pulse during playback is always the same as during recording, so when self-recording and playback in 1/3 mode, the total delay of mono multi 42 and 43 The reproduced FM video signal level is always at the maximum regardless of the amount. Therefore, 1/
By adjusting the total delay amount of mono multi 42 and 43 to the value that maximizes the playback FM video signal level when playing back a standard tape in 3 modes, the tracking preset in 1/3 mode can be improved. This allows for set correction.

Note that the tracking preset correction is to make the phase difference between the output drum pulse of the flip-flop 17 and the reproduction control pulse of the control head 4 a constant value. In addition to delaying the flip-flop 1 only during playback,
a first delay means that delays the output drum pulse of No. 7 and supplies it to the trapezoidal wave generation circuit 18; a second delay means that delays the output signal of the countdown circuit 31 only during playback and supplies it to the monomulti 21; Fifth
A third delay means using monomultis 39 and 40 shown in the figure can be considered. However, as in the present invention, a monomulti that delays the vertical synchronization signal (or a signal synchronized with this, such as a drum pulse) during 1/3 mode recording and records it as a control pulse can also be used during playback with the same amount of delay. Considering this, as the amount of delay increases, the phase of the control pulse relative to the drum pulse must be delayed, and the first delay means is the only one other than this embodiment that satisfies this condition. . However, since this first delay means delays the drum pulse, this amount of delay becomes a phase delay element of the drum servo system, making the operation of the drum servo system unstable, which is not desirable. On the other hand, even if the output signal of the countdown circuit 31 is delayed by using the monomultis 42 and 43 as in this embodiment, since the monomultis 42 and 43 are the reference signal system, this amount of delay is limited to the capstan servo system. This is optimal because it does not become an unstable element.

Furthermore, the present invention is applicable to a magnetic recording/reproducing device that can select not only the 1/3 mode but also the 1/2 mode as a mode other than the standard mode. /2 mode, when recording and reproducing in 1/3 mode or 1/2 mode, switch the changeover switches 45 and 46 in FIG.
The time constant of 2.43 is varied. In the above explanation, the mechanical fixing position of the control head is assumed to be the normal position in standard mode, but it may not be the normal position in one mode other than standard mode, such as 1/3 mode or 1/2 mode. The position may be electrically corrected in the same manner as described above, or it may be fixed at a position that is not normal in any mode, and electrical correction may be made during recording and reproduction in all modes. Furthermore, the present invention can also be applied to a magnetic recording/reproducing device in which a rotary head is shared in each mode.

As described above, the tracking preset correction circuit according to the present invention includes a first pulse delay circuit that performs self-recording in the first recording and reproducing mode among a plurality of recording and reproducing modes so that the reproduced signal level is maximized. an adjusting means for adjusting the amount of delay; and an adjustment means for adjusting the amount of delay so that the playback signal level obtained by playing back the standard tape in the second recording and playback mode among the plurality of recording and playback modes in the second recording and playback mode is maximized. The second pulse delay circuit is adjusted, and the second pulse delay circuit and the first pulse delay circuit are separated during the first recording/reproducing mode, and the second pulse delay circuit is adjusted during the second recording/reproducing mode. A changeover switch connects the delay circuit and the first pulse delay circuit in series, and switches the vertical synchronization signal in the video signal to be recorded or a signal phase-synchronized thereto to the second pulse delay circuit when recording in the first recording/playback mode. The control pulse is supplied to the fixed control head through the second pulse delay circuit when recording in the second recording/reproduction mode, and is recorded on the magnetic recording medium as a control pulse. To correct tracking presets in modes other than the first recording/playback mode above, play the standard tape for that mode and adjust the playback FM.
This can be done simply by variably controlling the delay amount of the second pulse delay circuit so that the signal level is maximized, and thus the tracking preset correction operation can be simplified compared to the conventional method. Since the circuit is shared during recording and playback,
The circuit configuration is simpler and cheaper than conventional circuits, and since the second pulse delay circuit is installed in the reference signal system during playback, it prevents the capstan servo system from becoming unstable. It has features such as being particularly suitable for application to household magnetic recording and reproducing devices.

[Brief explanation of the drawing]

Figure 1 shows an example of a track pattern when recording in 1/3 mode of a magnetic recording/reproducing device that uses a rotating head to record and reproduce data in both standard mode and 1/3 mode, and Figure 2 shows a rotating head for standard mode. head and 1/3
Figure 3 is a diagram showing an example of the rotary drum attachment position of each rotary head for standard mode and 1/3 mode. Figure 4 is a diagram explaining the X value. Figure 5 is a diagram showing the rotary head for mode. 6 is a circuit system diagram showing an example of a conventional circuit, FIGS. 6A to 6I are signal waveform diagrams for explaining the operation of FIG. FIGS. A to I are signal waveform diagrams for explaining the operation of FIG. 7, respectively. 3, 3', 4...control head, 5...
Video signal input terminal, 8, 10, 11, 13, 2
0, 21, 32, 33, 34, 39, 40, 4
2, 43, 44... Monostable multivibrator (mono multi), 9, 14, 27... Record/playback switch, 15... Drum motor, 17... Flip-flop, 19, 29... Sampling hold circuit, 23... ...capstan motor, 31...
...Countdown circuit.

Claims (1)

[Claims] 1. In any of a plurality of recording/reproducing modes with different magnetic recording medium running speeds, track pitches, etc., a capstan servo system reference signal delayed through a first pulse delay circuit is Provided in a magnetic recording/reproducing device that controls the rotation of the capstan motor based on a signal obtained by phase comparison with a stun motor rotation detection pulse or a reproduction control pulse, and performs recording and reproduction by selecting an arbitrary mode. In a tracking preset correction circuit that maintains a constant phase difference between a drum pulse used in a drum servo system and a reproduction control pulse supplied to a capstan servo system, the first of the plurality of recording and reproduction modes is selected. adjusting means for adjusting the delay amount of the first pulse delay circuit so that the reproduction signal level is maximized by self-recording in a first recording and reproduction mode; and a second recording and reproduction mode among the plurality of recording and reproduction modes. a second pulse delay circuit whose delay amount is adjusted so that a playback signal level obtained by playing back a standard tape in the second recording and playback mode is maximized; Switching to disconnect the second pulse delay circuit and the first pulse delay circuit, and connect the second pulse delay circuit and the first pulse delay circuit in series during the second recording/reproducing mode. switch, the vertical synchronization signal in the video signal to be recorded or a signal phase-synchronized therewith is transmitted without passing through the second pulse delay circuit during recording in the first recording/playback mode, and in the second pulse delay circuit. 1. A tracking preset correction circuit comprising a recording means for supplying a control pulse to a fixed control head through the second pulse delay circuit and recording it on a magnetic recording medium as a control pulse during recording in a recording/reproduction mode.