JPS59185058A - Magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic recording and reproducing apparatus, and more particularly to a magnetic recording and reproducing apparatus that performs tracking control using a pilot signal recorded by a rotary head.

[Background of the invention]

Conventionally, in magnetic recording and reproducing devices, especially for home use, two rotating heads with different azimuth angles are alternately scanned obliquely to the longitudinal direction of a magnetic tape, without providing a guard band (for recording video signals). , the so-called rotating head
A helical scan azimuth recording method is used.

Tracking information is provided so that the rotary head can correctly scan the azimuthally recorded tracks on the magnetic tape during reproduction. One of the tracking control methods is to use a pilot signal that serves as tracking information during playback.
A method has been devised in which the pilot signal is recorded on a video track of a magnetic tape by a rotary head in a superimposed manner with a video signal, and the pilot signal is detected during playback to form a tracking error signal to perform tracking control.

The tracking control method using this pilot signal is
Since tracking errors can always be detected, this method has the advantage that sufficient tracking control performance can be obtained, especially when recording for a long time by narrowing the recording track pitch. Furthermore, automation of tracking control is achieved, and there is no need for the user to make tracking adjustments while looking at reproduced images.

However, this method has the disadvantage that it is easily affected by fluctuations in the reproduction level of the pilot signal because the tracking error is detected from the reproduction level of the pilot signal. The playback level of this pilot signal is determined by many factors, such as the type of tape or head used (differences in material, shape, manufacturing method, etc.), the frequency characteristics of the rotary transformer, variations in recording level adjustment, and variations in the gain of the playback system. For example, in the worst case, it fluctuates significantly, exceeding ±10 dB.

The sound of a change in the reproduction level of the pilot signal with respect to the tracking deviation of the rotating head is the tracking error detection sensitivity, and the loop gain of the tracking control system increases or decreases in proportion to this detection sensitivity. Therefore, when the reproduction level of the pilot signal decreases significantly, the loop gain of the tracking control system decreases significantly, the pull-in range and holding range of the tracking control system become narrower, and the tape speed control system's slight speed decreases. Tracking control can also be lost due to fluctuations, and conversely, if the reproduction level of the pilot signal increases significantly, the loop gain of the tracking control system will be greatly increased to 0, resulting in phase margin and gain margin. This results in an unstable state such as oscillation. Since the tape speed exhibits a hunting phenomenon, periodic fluctuations in tracking and wow and fluff of audio signals recorded on tracks in the longitudinal direction of the tape are significantly degraded.

Furthermore, if the pilot signal reproduction level fluctuates significantly, it becomes necessary to set the normal operating range of the circuit operation in the pilot signal reproduction processing system, the so-called dynamic range, to an extremely wide range, which causes the power supply voltage to become abnormal. This results in inconveniences such as a significant increase in power consumption.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to obtain a magnetic recording/reproducing device that can achieve stable tracking control by reducing variation in loop gain of a tracking control system.

[Summary of the invention]

In order to achieve the above object, the present invention uses a rotary head to reproduce four types of pilot signals, each having a different frequency, which are alternately recorded on a magnetic tape, and uses the reproduced pilot signal as the main signal to be scanned by the head. In a magnetic recording and reproducing apparatus that is equipped with a device that detects a reproduction level difference between pilot signals recorded on adjacent tracks on both sides of a track and performs tracking control of the head according to this reproduction level difference, reproduction of the pilot signal is performed. level,
Alternatively, among the levels obtained by adding the reproduction levels of the pilot signals recorded on both adjacent tracks, a small variation in the level (at least one level) is automatically reduced.

[Embodiments of the invention]

The present invention will be explained below using the drawings. First, a tracking control method using pilot signals will be explained with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing a track pattern of a tape recorded by superimposing a four-frequency pilot signal on a video signal. Further, FIG. 2 is a block diagram showing an apparatus for forming a tracking error signal TR from a reproduced pilot signal PL.

In FIG. 1, Al and A2 represent the rotating video head 5.
B1 and B2 are video tracks recorded by the rotary video head 6. Further, f, to f4 indicate the frequencies of pilot signals recorded on the respective video tracks. In this way, four-frequency pilot signals are alternately recorded for each video track in a predetermined rotation. The frequencies f, to f4 of these pilot signals are lower than the frequency band of the video signal, and are lower than the frequency band of the video signal. A low frequency is chosen so that it is not affected much by the azimuth angle.

Therefore, when the video head 5.6 scans the recorded video track during playback, it detects not only the pilot signal of the main video track that is being correctly scanned, but also the pilot signals from the video tracks adjacent on both sides. I can do it. Therefore, by detecting the reproduced levels of the pilot signals from both adjacent tracks and finding the difference between the levels, it is possible to obtain an accurate tracking error signal that includes the direction and magnitude of the tracking deviation.

Now, the four-frequency pilot signals 10 and 5 shown in FIG.
If fH, f, = 9.5 fH (here, fH is the frequency of the horizontal synchronization signal of the video signal), video track A1
+ When scanning A2, if the tracking shifts to the right, l f, -f21 = l f, -f41 = r
When the H component increases and shifts to the left, l f, -f41
= 1f, -f, l = 3 fu acid component increases. Furthermore, when scanning video tracks B, B2, if the tracking shifts to the right, 1f2-f, l = l f, -
f, l = 3 fH acid component increases; conversely, if it shifts to the left, l f2- f, l -1f, -f, l = fH component increases.

Therefore, in FIG. 2, a local signal having the same frequency as the pilot signal recorded on the main video track to be scanned is generated by the pilot signal generation circuit 9, and this local signal F and the automatic gain control circuit 23 are generated. After adjusting the level and amplifying the reproduced pilot signal P L' with the amplifier 27, the reproduced pilot signal P L' is sent to a frequency conversion circuit 30 consisting of, for example, a double-balanced modulator, and its output is a signal having the difference frequency between the two signals, that is, the A composite signal of fH acid component and 3fH component is obtained. Next, from this composite signal, fH acid components 3f are filtered by bandpass filters 51 and 32, respectively.
Separate the H component and further add an envelope detection circuit 33.3
4, a voltage signal p, , with a value corresponding to each amplitude,
p.

After that, when the difference between the two is determined by the differential amplifier 65, the fH acid component 3 fH acid component difference voltage signal T, T is obtained as the differential output. This differential voltage signal T, T represents the difference in level of pilot signals detected from adjacent trunks on either side of the main track being scanned.

At this time, when the main track is A or A2, and when the main track is B1
Alternatively, in the case of B2, as described above, the direction of increase/decrease of the difference frequency component with respect to the direction of tracking deviation is reversed. Therefore, the differential amplifier 65 generates two differential voltage signals with different polarities, T=K("l"2), T=k(B2-P,
), (k: constant) are output, and each of these differential outputs T and T is supplied to a gate circuit 36.57, and the rotational phase of the video head 5.6 is detected.The Herad phase of one frame period is detected. The detection signal SW and a signal whose polarity is reversed by the inverter circuit 40 are used as gate signals, and the gate circuits 36 and 37 are activated during the period when each gate signal is at a high level.
By closing the gate and transmitting the signals T and T alternately for each field, the difference voltage signals T and T with different polarities are connected for each scan of one track, and a continuous correct tracking error signal TR is generated. obtain.

In this way, the tracking error detection circuit 22 of FIG. 2 can form the tracking error signal TR from the reproduced pilot signal Pl.

Next, FIG. 3 is a block diagram showing an example of the configuration of a magnetic recording/reproducing apparatus using a rotating head helical scan azimuth recording method according to the present invention.

FIG. 3 shows the configuration of the reproduction system, but does not show the configuration of the recording system. However, for convenience of explanation, the operation during recording will be briefly described using FIG. 6. When recording a video signal, the tape 1 is driven by a capstan 2 and runs in the direction of the solid arrow. This capstan 2 is rotationally driven by a capstan motor 3.

On the other hand, video heads 5.6 mounted on the rotary cylinder 4 180 degrees apart from each other are driven by the cylinder motor 7 and rotate in the direction of the dashed arrow. This cylinder 4 is attached to a rotating shaft inclined with respect to the longitudinal direction of the tape 1, and is driven to rotate at a frequency of 172 (ie, a frame frequency of 30H2) of a vertical synchronizing signal of a recorded video signal. Further, the tape 1 is wound around the cylinder 4 over approximately half a circumference. Therefore, video head 5
．． 6 alternately scans the tape 1 in a diagonal direction from bottom to top, and records the video signal and the tracking pilot signal in units of one field of the video signal.

Next, the operation when playing back at standard speed will be explained.

During standard playback, the rotational phase of the video head 5.6 is detected by the tack head 13, this detection signal is sent to the phase adjustment circuit 14, and the reference signal REF generated by the output 15 is sent to the phase comparator. The video head 5.
6 is rotated at a constant phase and speed determined by the reference signal REF. If the frequency of this reference signal REF is selected to be approximately equal to the frame frequency, the rotational speed of the video head 5.6 will be approximately equal to that during recording.

With the video head 5.6 being rotated at a predetermined speed in this manner, by controlling the running of the tape 1 using the above-mentioned tracking error signal T, the video head 5.6 is moved over a desired recording video track. Tracking control is performed to ensure accurate scanning. Next, this tracking control operation will be explained. First, although not shown,
The rotational speed of the capstan 20 is detected by a speed detector, and this detection signal is sent to a frequency discriminator to convert it into a speed control voltage according to the rotational speed. By supplying this to the motor 6, speed control is performed so that the capstan 2 rotates at a predetermined speed.

- Should the signal reproduced from the tape 1 by the video head 5.6 pass through the rotary transformer 12 to the amplifier 1
Send it to 9 and amplify it. This amplified reproduction signal F
is further sent to the video signal reproducing circuit 20, and
The signal is sent to the tracking error detection circuit 22 via the low-pass filter 21. By the band pass filter 21,
The high-frequency video signal of the reproduced signal RF is removed, and only the pilot signal PL is separated and extracted. From this pilot signal PL, the tracking error detection circuit 22 generates a tracking error signal T using the method described in FIG.
form R. This tracking error signal TR is passed through the low-pass filter 23 and the capstan motor drive circuit 18.
The rotation of the cab stuff 20 is controlled by supplying the capstan motor 6 through the capstan motor 6. As a result, the running phase of the tape 1 is controlled in accordance with the tracking error signal T, and tracking control is performed so that the video head 5.6 correctly scans the video track.

Next, an embodiment of the present invention for reducing variations in the reproduction level of pilot signals will be described with reference to FIGS. 2, 4, and 5.

FIG. 2 is a block diagram showing an apparatus for forming a tracking error signal TR from a reproduced pilot signal PL. Second
In the figure, reference numeral 23 denotes an automatic gain control device according to the present invention, which includes an adder 24, an amplifier 25. It is composed of a gain control circuit 26. Further, FIG. 5 is a diagram showing an example of a specific circuit configuration of the automatic gain control device 23 shown in FIG.
Automatic gain control device 26. Bandpass filter 31.
32. A circuit example of each block of envelope detection circuits 33 and 34 is shown.

Next, Figure 4 shows the position scanned by the head during playback (horizontal axis).
3 shows the voltage changes (vertical axis) of the signals of each part of the tracking error detection circuit 22 with respect to the tracking error detection circuit 22.

In FIG. 4, (1) shows a trunk in which pilot signals of frequencies f1 to f are recorded, and (2) shows six examples of positions scanned by the rotating video head 6 during playback. Head 6 should now scan the main trunk,
Assuming that the track is recorded with a pilot signal of frequency f2, the best tracking is achieved when the head 6 scans the position shown in the center of FIG. 4 (2) (head position 00 point). Head 6 is exactly one track pitch to the left (
-P), and if the track on which the pilot signal of frequency f1 is recorded is scanned as shown on the left side of FIG. When scanning a track on which a biloft signal of frequency f is recorded, as shown on the right side of Fig. 4 (2), the pilot Signals other than the signal are not reproduced.

FIG. 4(3) shows the envelope detection circuit 33 of FIG.
fH acid component voltage signal P1, which is the output signal of 34, and
The voltage signal P2 of the H component is shown with respect to the scanning position of the hand 6. The main track to be scanned by the head 6 now is the track on which the pilot signal of frequency 12 is recorded, so the local signal F sent to the frequency conversion circuit 3o in FIG. 2 is the local signal D2 of frequency f2. .

Therefore, the signal P1 in FIG. 4(6) represents the reproduction level of the pilot signal of frequency f1, CP, :If.

ft l = fH), and the signal P2 represents the reproduction level of the pyro signal of frequency f3 (P2: I f
, -T21 = 3 fH). Ding, that is, both signals P,,
p2 represents the reproduction novel of the pilot signal detected by the head 6 from the left and right adjacent tracks.

Next, FIG. 4 (4) shows the difference voltage signal T=k (P, -P2) between the above-mentioned signals P1 and P2 with respect to the scanning position of the head A. Of this differential voltage signal T, the signal T1 indicated by a solid line and the signal T2 indicated by a broken line indicate when the reproduction level of the viroft signal is high (T1) and when it is low (T2), respectively. be. This differential voltage signal T is one output signal of the differential amplifier 65 shown in FIG. Open,
Since the gate circuit 36 is closed, this differential voltage signal T is output from the tracking error detection circuit 22 as the tracking error signal TR.

In FIG. 4 as well, the tape 1 runs to the left as in FIG. 1. In FIG. 4, if the head 6 is scanning to the left with a deviation within the range of 2 trunk pitches (-2P to 0), as is clear from FIG.
> P2, the differential voltage signal T shown in FIG. 4 (4) becomes high, and accordingly, the rotational speed of the capstan motor 3 shown in FIG. 6 increases and the tape 1 runs faster. Tracking control is performed so that the scanning position of the head 6 approaches the right main track.

Conversely, the head 6 moves to the right in a range of 2 track pitches (0 to 2
When scanning is performed with a deviation within P), Pl<P2 from Figure 4 (3), so the differential voltage signal T shown in Figure 4 (4) becomes low, and accordingly, the current The rotational speed of the stun motor O decreases and the tape 1 travels slowly, so tracking control is performed so that the scanning position of the head O approaches the left main track. In particular, if the tracking deviation of the head O becomes 1 left or right, If tracking is within the track pitch (-p to P), when tracking shifts to the left, signal P increases and signal P2 decreases; conversely, when tracking shifts to the right, signal P2 decreases.
increases, and signal P1 decreases.

This is shown in the change curve of signal T1 in Figure 4 (4).
It will be understood that this is the section from point to point ■, and the control center is at the stable point ■ where the signals P1 and P2 become equal and the difference voltage signal T=o. These points ■, ■, ■ are shown in Figure 4 (
This corresponds to the six scanning positions of the head shown in 2).

When one field period has elapsed during which the head 6 is tracking-controlled to correctly scan the main trunk where the pilot signal of frequency f2 is recorded,
Next, tracking control is performed so that the head 5 correctly scans over the main trunk on the right. In this case, the local signal F becomes a signal F3 with a frequency f, and the gate 37 in FIG. becomes the tracking error signal TR, but since the operation is basically the same as that explained in FIG. 4, the explanation will be omitted.

In Fig. 4 (4), the signal W is the signal P in Fig. 4 (3).
, (the signal obtained by adding the fH acid component and the signal "2c5fH component) is shown for the scanning position of the head 6 (
W'=m (P, + P2), m: constant]. Of this added signal W, the signal W1 shown by a solid line and the signal W2 shown by a broken line indicate when the reproduction level of the pilot signal is high (W, ) and when it is low (Wt), These correspond to the differential voltage signals T, T2, respectively. If the fH acid component signal P1 and the 3fH component signal P2 shown in Fig. 4 (3) change sinusoidally with respect to the scanning position of the head A, as shown in Fig. 4 (4), they do not depend on the head position. It becomes a constant value. In reality, the signals P, P2 exhibit changes that deviate slightly from the sine waves, and in this case, the added signal W changes somewhat with respect to the head position, but even with this change, the effect of the present invention is still , is exactly the same as the case where the addition signal W is a constant value as shown in FIG. 4 (4).

What should be noted in FIG. 4 is that the value of the addition signal W shown in FIG. f, that is, the differential voltage signal T shown in FIG. 4 (4)
] changes with respect to the head position, that is, it changes depending on the tracking error detection sensitivity. This is because when the reproduction level of the pilot signal increases or decreases, the levels of the fH acid component signal P1 and the 3fH component signal P2, which are the pilot signals themselves detected from the left and right adjacent tracks, also increase or decrease. This phenomenon is caused by the fact that the tracking error signal TR, which is the difference between P and P2, and the addition signal W, which is the sum of this signal P and P2, both increase and decrease.

The feature of the embodiment of the present invention shown in FIGS. 2 and 5 is that the sum signal W of the fH acid component signal P1 and the three components P2 is detected, and the amplitude of the input pilot signal is The point is to control.

In Figure @2, the above two signals P, P2, which are the outputs of the envelope detection circuits 33 and 34, are added by an adder 24, and the output sum signal W is amplified by an amplifier 25, and then the amplified addition signal is The signal W' is sent to a gain control circuit 26 to control the gain control circuit so that a pilot signal of a constant amplitude is always supplied to the next stage amplifier 27 even when the level of the input reproduced pilot signal PL varies.

A more specific circuit example of the automatic gain control device 2 shown in FIG. 2 will be explained with reference to FIG.

In FIG. 5, 31 is a bandpass filter using LC parallel resonance with a center frequency of fH, and the frequency conversion circuit 30
The fH acid component included in the output signal is selectively amplified and sent to the envelope detection circuit 33 at the next stage. In the envelope detection circuit 36, the transistor Q1 and the capacitor C8
A voltage signal P1 is generated according to the amplitude of the H acid component. on the other hand,
32 is a bandpass filter using LC parallel resonance with a center frequency of 3 fH, and the output signal 1 (
The included 3fH component is selectively amplified and sent to the envelope detection circuit 34 at the next stage. In the envelope detection circuit 34, the transistor Q2 and the capacitor fC form a voltage signal P2 corresponding to the amplitude of the 3fH component. After adding and smoothing this fH acid component signal P and the 3fH component signal P2 by an adder 24 consisting of a resistor, a capacitor, and a capacitor C3,
The output sum signal W is amplified by an amplifier 25 having an operational amplifier configuration. The output signal W of this amplifier 25 is sent to a gain control circuit 26. This gain control circuit 26 includes a resistor fLs
, k, &, consists of a capacitor C4 and a transistor Q3, and the input reproduction pilot signal PL is connected to a resistor R5,
Transistor Q3 used as a variable impedance element
The impedance of the transistor Q is changed according to the value of the addition signal W' supplied via the resistive wind, and the amount of attenuation of the reproduced pilot signal PL is divided by the impedance between the emitters of the corefthal. It is a configuration that is controlled by That is, the regenerated pilot signal P
When the amplitude of L is in the range of °C, the addition signals w and w' of the fH acid component signal P and the 3fH component signal P,
1, the collector-to-emitter interference of transistor Q decreases, and the amount of attenuation of the reproduced pilot signal by resistor R8 increases, causing the base potential of transistor Q to rise. A substantially constant regenerated pilot signal is sent to the amplifier 27 of.

By such a foot loop, the signal P1
The signal W& which is the sum of
f, that is, the tracking error detection sensitivity is always approximately constant. As a result, the addition signal W shown in FIG.
f, that is, the differential voltage signal T), is also controlled so that it always has a changing characteristic such as T, for example.

In addition, in FIG. 5, the capacitor C of the gain control circuit 26
Reference numeral 4 denotes a simple DC blocking capacitor, and its capacitance value is selected so that the impedance is sufficiently smaller than the impedance of the transistor Q in the frequency band of the pilot signal.

In this way, the automatic gain control circuit 2 shown in FIGS. 2 and 5
By adding 3, the following effects can be obtained.

(1) Even if the level of the playback pilot signal PL varies significantly due to differences in the characteristics of the tape or head, the level of the pilot signal PL' and the level of the pilot signal PL' on both sides of the playback will vary. Since the level of the signal W obtained by multiplying the signals P and P2, which are the reproduced levels of the pilot signals, is always approximately constant, the tracking error detection sensitivity is made constant.

(2) Amplifier 27° frequency conversion circuit 30 in the automatic gain control loop.ノ(donokusufilta31゜32
, even if the gains of the envelope detection circuits 35 and 34 vary, the automatic gain control device 26 greatly reduces the variation in the signal W, which is the sum of the signals P and P2, so the tracking error detection sensitivity is It always remains almost constant.

Therefore, in addition to the above effect (1), variations in the loop gain of the troubleshooting control system are significantly reduced.

In this way, the fi acid component signal P and the 3tH component signal P2
According to the method of this embodiment in which the signal W obtained by adding the
．． s2. and the signal P at the subsequent stage of the frequency conversion circuit 60, which has large gain variations because it is difficult to configure a negative feedback amplifier.
,,P.

Since the gain of these circuits is detected and the gain is controlled, variations in tracking error detection sensitivity due to the gain of these circuits can be significantly reduced.

(6) Although the amplitude variation is very large, the amplitude itself is made constant at the stage of the input regenerated pilot signal, which is very small. , the dynamic range required for each circuit in the signal processing system is determined by the automatic gain control circuit 23.
Since it is much narrower than in the case without it, low voltage driving is possible, low power consumption is achieved, and it is easy to integrate it into an IC.

Next, a second embodiment of the present invention will be described using FIG. 6. FIG. 6 is a diagram showing the automatic first gain control device 28 and its peripheral circuit configuration. In FIG. 6, the amplitude of the regenerated pilot signal PL', which is the output signal of the amplifier 27, is amplified by the amplifier 29, and then envelope-detected by the diode D and capacitor C3, and this detected voltage is applied to the transistor q.
In addition to the noise, the impedance between the collector and emitter of the transistor q is changed, and the input regenerative pilot signal PL is divided and attenuated by the resistive wind and the transistor q as a variable impedance element, so that the amplifier 27 always receives almost constant regeneration. This configuration supplies a pilot signal.

The embodiment shown in FIG. 6 is a method of detecting the amplitude of the reproduced pilot signal PL' which is the output of the amplifier 27, and detects the amplitude of the reproduced pilot signal PL' which is the output of the amplifier 27. This is a method of detecting the total amplitude of the synthesized product.

〔Effect of the invention〕

As described above, according to the present invention, the rotary head performs tracking control according to the reproduction level difference of the pilot signals recorded on the adjacent tracks on both sides of the main track of the scanner, and also controls the reproduction level of the pilot signal. Since an automatic gain control device is provided to reduce the variation in the level of the pilot signals recorded on both adjacent tracks, or the variation in the level of the sum of the reproduction levels of the pilot signals recorded on both adjacent tracks, the tracking error detection sensitivity is always almost constant, and the tracking control system Since the variation in loop gain is significantly reduced, stable and high-performance tracking control can be achieved. Furthermore, since the required dynamic range of the pilot signal reproduction processing system is reduced, it is possible to achieve lower power consumption by lowering the power supply voltage.

The present invention is applicable not only to standard playback, but also to special playback, including still image playback, in which tape speeds are varied and played back.

[Brief explanation of drawings]

FIG. 1 is a Chive pattern diagram, FIG. 2 is a block diagram showing an example of a tracking error detection circuit, FIG. 6 is a block diagram showing an example of the configuration of a magnetic recording/reproducing device according to the present invention, and FIG. 5 shows voltage changes of various signals with respect to the head position to explain the operating principle of the present invention. FIG. 5 is a partial circuit diagram showing a specific example of an automatic gain control device, and FIG. 6 is an automatic gain control device. FIG. 7 is a partial circuit diagram showing another embodiment of the gain control device. 1... Magnetic tape 2... Capstan 6... Capstan motor 4... Cylinder 5.6... Rotating head 9... Pilot signal generation circuit 18... Capstan motor drive circuit 22... Tracking error detection circuit 23, 28, automatic gain control device 24, adder 25, amplifier 26, gain control circuit 27, amplifier 30, frequency conversion circuit 31, 32, band pass Filters 33, 34...Envelope detection circuit 65...Differential amplifier 36, 37...Gate circuit 8j Figure 2, No. b, 28

Claims (1)

[Claims] a rotating head that diagonally scans a magnetic tape, a device that generates four types of pilot signals each having a different frequency, and a device that uses the head to alternately record the four types of pilot signals on the magnetic tape; a device for reproducing the pilot signal recorded on the magnetic tape by the head; and a reproduction level of the pilot signal recorded on adjacent tracks on both sides of the main track scanned by the head based on the reproduced pilot signal. In a magnetic recording/reproducing apparatus, the magnetic recording/reproducing apparatus includes a device for detecting the difference in the pilot signal and a device for performing tracking control so that the head correctly scans the main track of the magnetic tape according to the reproduction level difference. playback level,
Alternatively, a magnetic recording and reproducing apparatus characterized in that variations in at least one of the levels obtained by adding the reproduction levels of pilot signals recorded on both adjacent tracks are automatically reduced.