JPH0239015B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an auto-tracking device in a magnetic recording/reproducing device.

[Conventional technology]

Magnetic recording and reproducing devices are used in many technical fields because they can extremely easily record and reproduce information signals. It is well known that it is widely used, especially in consumer products.

By the way, as the demand for high-density recording of information on magnetic recording media such as magnetic tape increases,
Progress has been made in narrowing the track width. However, for densification using this method,
There are restrictions in terms of mechanical precision in the drive system of the magnetic recording medium, the drive system of the magnetic head, and the like. This point is especially important for consumer products that require low cost.
This is a problem in magnetic recording and reproducing devices such as VTRs.

Therefore, in order to realize high-density recording and reproducing on magnetic recording media such as magnetic tapes, in addition to narrowing the recording trace width, the reproducing magnetic head is controlled by a tracking servo system during reproduction. A so-called auto-tracking device is required, which allows the user to accurately scan the recorded trace at all times.

Several types of auto-tracking devices have been considered so far, and these types can be roughly divided into the following three types.

(1) One that uses amplitude changes in the reproduced RF signal (reference signal).

(2) A pilot signal is recorded in advance for each track, and leakage signals from adjacent tracks are used.

(3) Those using an auxiliary head.

[Problem to be solved by the invention]

In all of the above-mentioned methods, the position of the head and the feeding speed of the tape are controlled based on the detected tracking error signal. However, when the track width becomes narrower, for example, less than 10 μm, a tracking error signal of sufficient level and accuracy cannot be obtained by using these methods alone.

SUMMARY OF THE INVENTION An object of the present invention is to provide an auto-tracking device that can ensure good tracking performance even in magnetic recording and reproducing devices such as VTRs in which the width of recording traces is narrowed.

[Means to solve the problem]

A pair of recording rotary heads consisting of first and second recording heads are attached to the outer periphery of the rotating structure of the tape guide drum with an opening angle of 180° via an electro-mechanical conversion element such as a bimorph. Further, in the vicinity thereof, a pair of reproducing rotary heads consisting of the first and second reproducing heads are connected with an opening angle of 180° via an electro-mechanical transducer such as a bimorph, as described above. Attach. The first recording head and the first reproducing head are disposed close to each other, and the heights and the like between them are adjusted so that they scan on the same track. Similarly, the second recording head and the second reproducing head are placed close to each other, and the heights etc. between them are adjusted so that they scan on the same track. It is being Also, the gap length of the recording rotary head in the track length direction is
It is widened to accommodate the larger dimensions of the reproducing rotary head. The first recording head and the second recording head have different azimuth angles in opposite directions with respect to the length direction of the track, and the first reproducing head and the second reproducing head have different azimuth angles in opposite directions. They also have different azimuth angles in opposite directions. The first recording head and the second reproducing head have the same azimuth angle, and the second recording head and the first reproducing head have the same azimuth angle.
The reproducing heads also have the same azimuth angle. Furthermore, the first recording head and the second recording head have head widths (widths of opposing magnetic pole surfaces in the gap portion) that are the same as the head widths of the first reproduction head and the second reproduction head, respectively. It is said to have the same or larger dimensions. The signal processing circuit includes a pilot signal generating section that generates a pilot signal whose characteristic information such as frequency differs between adjacent recording tracks, and a pilot signal generator that generates a reproduced pilot signal from the signal reproduced from the magnetic tape by the recording rotary head. a tracking error signal forming circuit for forming a tracking error signal from the reproduced pilot signal, and a control circuit for driving the electro-mechanical conversion element using the tracking error signal. There is.

[Effect]

The pilot signal generated by the pilot signal generator is recorded on the magnetic tape surface by the recording rotary head. Since the first recording head and the second recording head have different azimuth angles, the recording heads alternately produce recording patterns with different azimuths. During reproduction, the recording rotary head is used as a tracking sensor for the reproducing rotary head. That is, the first recording head and the first reproducing head are caused to scan over the same recording track, and the pilot signals of the main track and its adjacent tracks being scanned are reproduced together with the main signal. Similarly, the second recording head scans the same recording track as the second reproducing head, and reproduces the pilot signal of the main track and its adjacent track together with the main signal. 1st and 2nd above
The recording head reproduces the pilot signal while spanning the main track and the adjacent tracks on both sides thereof. At this time, the first and second
The recording heads correspond to the recording signals of each main head at different azimuths in opposite directions, and correspond to the recording signals of the tracks adjacent to each main track at different azimuths in the same direction. It corresponds to azimuth. On the other hand, the first and second reproduction heads correspond to the recording signal of each main track with an azimuth in the same direction. The first and second reproducing heads are caused to scan within the main track with head widths equal to or smaller than those of the first and second recording heads, respectively. The mixed signal reproduced by the first and second recording heads is
It is separated by a pilot signal detection circuit such as a bandpass filter and becomes a reproduced pilot signal. This reproduction pilot signal is generated by a tracking error signal forming circuit equipped with an adder, a frequency conversion circuit, etc., and corresponds to the amount and direction of deviation of the first and second reproduction heads from the main track. is converted into a tracking error signal. That is, in this tracking error signal forming circuit, the level of one of the fixed frequency signals that differs depending on whether the reproducing rotary head shifts to the right or left with respect to the main track increases. It is said that the structure is as follows. This tracking error signal is
A control circuit connected to the subsequent stage is activated so that electric power is controlled and supplied to an electro-mechanical conversion element such as a bimorph in which the reproducing rotary head and the recording rotary head are mounted. , displacing the electro-mechanical transducer by a predetermined amount. This allows the reproducing rotary head to be tracked.

〔Example〕

Next, a case will be described in which an embodiment of the present invention is applied to a helical scan type two-head type VTR.

FIG. 1 is a plan view of a tape guide drum of a rotary head device used in the present invention. 1W and 2W are rotary heads for recording main signals, and as shown in FIG. 1, they are mounted on the rotary structure at an angular interval of 180 degrees from each other and are rotated on the same rotational plane around the central axis of rotation. 1R and 2R are main signal reproducing rotary heads which, as shown in FIG. 1, are mounted on the rotary structure at an angular interval of 180 degrees from each other and are rotated on the same rotation plane. Furthermore, as shown in FIG. 2, the center line of the head width of the recording rotary heads 1W, 2W (=width dimension in the head width direction of the opposing magnetic pole surfaces of the empty 1WG, 2WG) and the center line of the head width of the recording heads 1R, 2R. The main signal is reproduced by aligning the center line of the head width (=width dimension in the head width direction of the opposing magnetic pole surfaces of 1RG and 2RG), and using the head width g _W of the main signal recording rotary heads 1W and 2W. The head width g _R of the rotary heads 1R and 2R.

The head width g _W of the recording rotary heads 1W and 2W is
Head width of main signal reproducing rotary heads 1R and 2R g _R
By making the head larger and larger than the track width, the recording rotary heads 1W, 2W are
Regardless of the position of the main signal reproducing rotary heads 1R and 2R on the reproducing track, the pilot signal recording portions of the adjacent tracks on both sides of the reproducing track (main track) are sufficiently covered and the reproducing level of the pilot signal is raised. This is extremely advantageous. Further, the width g _R of the main signal reproducing rotary heads 1R, 2R is set to be equal to or smaller than the track width in order to reproduce only the main signal with as little noise as possible. When the head width g _R is made equal to the track width, the heads 1R, 2R
The playback output will be at the maximum level. In this embodiment, the width g _R of the heads 1R and 2R is equal to the track width. Furthermore, the center lines of the head widths g _W and g _R of the main signal reproducing rotary head 1R for the recording rotary head 1W and the main signal reproducing rotary head 2R for the recording rotary head 2W do not necessarily coincide with each other. It is not necessary that the main signal reproducing rotary heads 1R, 2R are arranged so that the pilot signals reproduced by the recording rotary heads 1W, 2W from adjacent tracks on both sides of the main head whose center is being scanned. As long as the signal reproduction levels are adjusted by a signal processing circuit such as a bandpass filter so that they are balanced, the deviation between the center lines of the head widths g _W and g _R is within a practical range. The above is acceptable without any problems. However, as mentioned above, the center lines of the head widths g _W and g _R are aligned,
In addition, under the condition that the head width g _R of the main signal reproducing rotary heads 1R and 2R is equal to the track width, the pilot signal with a high reproduction value level and the maximum value level can be reproduced with high precision and balance. The main signal can be easily obtained. Here, 2g _R =
The case of the relationship g _W will be explained.

Furthermore, the azimuth angles of the main signal recording rotary head and the reproducing rotary head are made different. here,
The azimuth angle of the rotating head for main signal recording is set to 17°.
A case will be explained in which the azimuth angle of the rotating head for reproduction is -17°.

As shown in FIG. 1, the magnetic tape 3 is wound diagonally around the tape guide drum 4 over an angular range of 180 degrees. This is run in the direction shown by arrow 5, and heads 1W, 1R, 2W, 2
Rotate R in the direction shown by arrow 6.

Then, as shown in FIG.
Video signal recording traces of 2B, 3A, 3B, etc. are formed. The recording traces 1A, 2A, 3A, . . . formed by the second recording head 2W are recording traces at an azimuth angle of -17°, and the recording traces 1B, 2B, 3B formed by the first recording head 1W are ... is a record of the azimuth angle +17°.

At this time, pilot signals of the following four different frequencies ₁ to ₄ are sequentially recorded for each track. ₁ = 10.5h ₂ = 9.5h ₃ = 6.5h ₄ = 7.5h h = horizontal frequency Track A recorded by the second recording head 2W is recorded at frequency ₁ or ₃ , and also recorded by the first recording head 1W. The recording frequency of the pilot signal is determined for each head so that track B to be recorded has a frequency of ₂ or ₄ . During reproduction, the pilot signals reproduced by the recording rotary heads 1W and 2W are as follows:
These are both the pilot signal of the main tracking error being scanned by the reproducing rotary heads 1R and 2R and the pilot signals of the left and right adjacent tracks adjacent to the main track. As shown in Fig. 3, the track on which the main signal is recorded is reproduced by a reproducing rotary head with the same azimuth angle, and the pilot signals of the adjacent tracks on the left and right are recorded at opposite azimuth angles. Therefore, the main signal recording rotary head having an azimuth angle in a direction opposite to that of the reproducing rotary head is used for reproduction. That is, the main signal and the pilot signal are reproduced by heads having azimuth angles in opposite directions. At this time, the main track pilot signal is
The recording head is reproduced with an azimuth opposite to that of the recording rotary head, while the pilot signals of both adjacent tracks of the main track are reproduced with an azimuth in the forward direction (the same direction). Conventionally, the pilot signal range was set to a low frequency with little azimuth loss, and crosstalk signals from adjacent tracks were used. However, this is not necessarily necessary if the azimuth angles are made different between the main signal recording rotary head and the reproducing rotary head as in the present invention.

When the frequency of the pilot signal is selected as described above, the following relationship exists between the pilot signals reproduced by the recording rotary heads 1W and 2W during reproduction.

| ₂ − ₁ | = | ₄ − ₃ | = h | ₂ − ₃ | = | ₄ − ₁ | = 3h In other words, if the frequency of the reproduced pilot signal component is converted using the pilot signal of the reproduced track, the frequency conversion is The output is 2 components: h component and 3h component.
Become a type. When playing track A, if the head shifts upward and scans, the h component increases, and if it shifts downward, the 3h component increases. Conversely, in track B, when the head shifts upward, the 3h component increases, and when the head shifts downward, the h component increases. Therefore, the h component and 3h component are extracted using a bandpass filter and used as a tracking error signal.

In this way, a tracking error signal corresponding to the tracking deviation can be obtained. Based on this tracking error signal, the main signal reproducing rotary heads 1R and 2R are automatically controlled to scan each main track differently, so as to perform so-called just tracking. If you move it to , auto tracking becomes possible.

Next, a method for moving the reproducing rotary heads 1R and 2R will be described.

As shown in FIG. 4, the first recording head 1W and the first reproducing head 1R are attached in the longitudinal direction of a bimorph plate 7 as an electro-mechanical transducer. In this case, the first recording head 1W
and the first reproducing head 1R so that the width direction of each cavity is orthogonal to the surface 7S of the bimorph plate 7 and the relationship shown in FIG. 2 is established.
The reproducing head 1R and the first recording head 1
W is attached to the bimorph plate 7. The other end of the bimorph plate 7 in the longitudinal direction, to which the first recording head 1W and the first reproducing head 1R are not attached, is fixed to the substrate 11.

When a control voltage controlled by the tracking error signal is applied to the bimorph plate 7 having such a structure via the input terminals 8A, 8B, and 8C, the bimorph plate 7 moves in a direction perpendicular to the surface 7S. As a result, the first recording head 1W and the first reproducing head 1R are moved in the width direction of the space. Second recording head 2W, second
The reproducing head 2R also has a similar mounting structure and operation.

Also, the coil terminal 9 of the first reproduction head 1R
Coil terminals A and 9B are used for reproducing the main signal, and coil terminals 10A and 10B of the first recording head 1W are used for recording the main signal and the pilot signal, and for reproducing the pilot signal.

Here, the installation positions of the main signal recording rotary heads 1W, 2W and the reproduction rotary heads 1R, 2R are as follows.
In particular, we will discuss the reason why both heads are installed with their width center lines aligned. For example, as shown in FIG. 5, when installing rotary heads 1W', 2W' for recording main signals with a head width g _W ' and rotary heads _1R ', 2R' for reproducing main signals with a head width g R', In other words, consider a case where one end of the space in the width direction of both heads is set to be offset from each other by a constant value (1/2g _R '). However, it is assumed that the head width g _W ' and the head width g _R ' are equal. In this case, as shown in FIG. 6, two different frequencies ₁ ' and ₂ ' are recorded sequentially in trap pitch g _W ' (g _R ') for each track.
During playback, the main signal recording rotary heads 1W' and 2
Scan the track boundary with W′.

When the main signal reproducing rotary head 1R' is reproducing N tracks, when the head 1R' shifts upward and scans, _{the 1} ' component increases, and when it shifts downward, _{the 2} ' component increases.

Conversely, in track A, when the head 1R' shifts upward, _{the 2} ' component increases, and when it shifts downward, _{the 1} ' component increases. In this way, a tracking error signal corresponding to the tracking deviation can be obtained, and if the reproducing head is automatically moved based on this signal, automatic tracking becomes possible.

However, this method has the following drawbacks.

(1) The track width recorded on the tape does not become a constant track width due to the difference in the mounting positions of the main signal recording rotary heads 1W' and 2W' and the vibration during running of the tape. For example, as shown in FIG. 7, track width T ₂ is different from other track width T ₁
If this is different (T ₁ >T ₂ ), the head will scan the positions 1R' and 1W' in FIG. 7, and the reproducing head 1R' will not scan the center of the track.

(2) Adjacent tracks 1A and 1B, 2A and 2B,...
are separate recording heads 1 that are different from each other.
Since pilot signals are recorded at W' and 2W', delicate adjustments are required in the head or recording system circuit in order to record at the same level. If this adjustment is not done well, there will be differences in tracking accuracy from track to track during playback.

(3) When the head scans positions 1R' and 1W' shown in Fig. 8, the pilot signal ₂ ' component of track 2B and the pilot signal of track 3B are
The sum of the ₂ ' components is the pilot signal for track 3A.
It becomes in equilibrium with the ₁ ′ component and enters a state of mistracking.

The above drawbacks do not occur if the main signal recording head and the reproducing head are mounted so that the center lines of their widths coincide with each other.

Next, a circuit for recording and reproducing pilot signals for the track and a circuit for controlling the head will be explained. FIG. 9 shows its block diagram. 1
1 is a horizontal synchronizing signal input terminal, 12a, 12b,
12c and 12d are pilot signals ₁ , ₂ , ₃ , ₄
13 is an input terminal for the switch 30 which is a 30Hz head switching signal, 14 is a ring counter with a 4 count period, 15a, 15b,
15c and 15d are analog switches; 16 is a recording video processing circuit that processes video signals in order to record them on a magnetic tape; 17 is an input terminal for a reproduced RF signal (reference signal) reproduced from the tape; 18a,
18b, 18c, and 18d are band pass filters for extracting pilot signals; 19 is an adder; 20 is an envelope detection circuit; 21 is a comparator; and 22 is a delay pulse circuit for generating delay pulses from SW30. 23 is an AND gate, 24
25e and 25f are frequency conversion circuits, 25e and 25f are band pass filters, 26e and 26f are envelope detection circuits, 27 is a differential amplifier, 28 is an analog switch, 29 is a low pass filter, 30 is a servo characteristic compensation circuit, 31 and 32 are head 1R ,1W,2
It is a bimorph plate with R and 2W attached.

The horizontal synchronization signal taken out from the color signal circuit of the video signal system of the VTR is input to the horizontal synchronization input terminal 11.
Enter. Using this as a reference phase, phase-locked pilot signals ₁ , ₂ , ₃ , and ₄ are generated by pilot signal generators 12a, 12b, 12c, and 12d. The four pilot signals are generated at all times, and are generated by four-phase pulses φ ₁ , φ ₂ , φ ₃ , φ ₄ shown in FIG. , this pilot signal can be switched. That is, when the signal from the switch 30 is input to the ring counter 14 through the input terminal 13, the four-phase pulses φ ₁ , φ ₂ , φ ₃ , φ ₄ shown in FIG. This signal is generated by a counter 14, which controls and operates an analog switch 15 so that pilot signals of ₁ , ₂ , ₃ , and ₄ are recorded on the magnetic tape for each track.

This ring counter 14 used in this embodiment is
As shown in FIG. 11, an inverter 33, a flip-flop 34, AND gates 35, 37,
It is composed of NOR gates 36 and 38. The four count cycles of the four pilot signals ₁ , ₂ , ₃ , and ₄ start from ₁ by inputting a set pulse to the set terminal 39 of the flip-flop.

Then, the recorded video signal from the recorded video signal processing circuit 16 and the pilot signal are mixed and recorded on the magnetic tape 3 by the main signal recording rotary heads 1W, 2W.

Next, the operation during playback will be explained. regenerative RF
The RF signals reproduced by the recording rotary heads W1 and W2 are input to the input terminal 17. Each pilot signal ₁ ,
₂ , ₃ , ₄ as band pass filters 18a, 18
b, 18c, and 18d and added to the adder circuit 19. On the other hand, the output envelope detection circuit 20 of the bandpass filter 18a extracting ₁ detects the signal, and the comparator 21 compares it with an appropriate level E to determine that it is a field in which ₁ is recorded. This is done by inputting the pulse formed by delaying the switch 30 by the delay pulse circuit 22 and the output of the envelope detection circuit 20 to the AND gate 23, as shown in the time chart of FIG.

Therefore, the phase of the four-phase pulse is set to _φ1 each time the pilot signal of frequency ₁ is reproduced.
In other words, a signal having the same frequency as the pilot signal of the reproduction track is always applied to the frequency conversion circuit 24 as a local signal. h from the frequency converted signal
The signals of the frequency component of
and is applied to the non-inverting input and the inverting input of the differential amplifier 27. A signal corresponding to the track deviation is obtained from the differential amplifier 27, but as explained earlier, the polarity of the signal is opposite depending on the track.
Therefore, analog switches 28e and 28f are set so that the non-inverted output of the differential amplifier passes during track A, and the inverted output passes during track B.
Switch to match the polarity. This signal is passed through a low-pass filter 29 to become a stable tracking error signal, and then a servo characteristic compensation circuit 30 improves the servo characteristic. The tracking error signal thus obtained is sent to the first recording head 1W.
Auto-tracking is performed by adding this to the bimorph board 31 on which the first reproducing head 1R is mounted, and the bimorph board 32 on which the second recording head 2W and second reproducing head 2R are mounted.

〔Effect of the invention〕

As described above, according to the present invention, even in a magnetic recording/reproducing apparatus such as a narrow track VTR, the magnetic head can always accurately scan a predetermined recording trace.

Furthermore, in the present invention, separate heads are used for the recording rotary head and the reproducing rotary head, so that dedicated heads with optimal specifications can be used for each. That is, during recording, a head with a wide gap length that can sufficiently record low frequency components is used, and during playback, a head with a narrow gap length that can reproduce high frequency components with high sensitivity is used. be able to.

Furthermore, if the head width of the recording head is made sufficiently larger than the head width of the reproducing head, a stable and sufficient level will always be maintained regardless of the position of the reproducing head on the reproducing track. The pilot signal is played.

Further, crosstalk between the heads, which occurs when the recording rotary head and the reproducing rotary head are set close to each other, is greatly reduced because the azimuth angles of the two heads are different.

[Brief explanation of drawings]

FIG. 1 is a plan view of a tape guide drum of a rotary head device used in the apparatus of the present invention, FIG. 2 is a front view of the head, FIG. 3 is a plan view of a tape showing an example of its recording pattern, and FIG. FIG. 5 is a perspective view showing an example of an installed state of the rotary head; FIG. 5 is a front view of the head for explaining another rotary head device; FIG.
7 and 8 are plan views of a tape showing an example of the recording pattern by the head of FIG. 5, and FIG. 9 shows a circuit for recording and reproducing a pilot signal and a circuit for controlling the head using the apparatus of the present invention. FIG. 10 is a timing chart of the ring counter, FIG. 11 is a block diagram of the ring counter, and FIG. 12 is a timing chart during reproduction. 1W, 2W...Recording rotary head, 1R, 2R
...Rotary head for reproduction, 3...Magnetic tape, 4...
...Tape guide drum.

Claims (1)

[Claims] 1. A magnetic tape 3 that includes a rotating structure that is rotated around a rotation center axis and that is wound around the outer circumference of the rotating structure.
a tape guide drum 4 for guiding the tape guide drum 4; disposed on a rotating structure within the tape guide drum 4 near its outer circumference at an angle of 180° from each other around the rotation center axis; The recording head 1W and the second recording head 2W rotate integrally with the rotating structure and have different azimuth angles in opposite directions. a recording rotary head 1 for scanning and recording at least signals on the magnetic tape 3;
W, 2W are located near the outer circumference of the rotating structure in the tape guide drum 4, and are connected to each other around the rotation center axis.
It forms an opening angle of 180 degrees and is arranged close to the pair of recording rotary heads 1W, 2W at a predetermined angle apart, and its gap length is less than or equal to the gap length of the recording rotary heads 1W, 2W. a first reproducing head 1R, whose head width g _R is equal to or smaller than the head width g _W of the recording rotary heads 1W and 2W, and which has different azimuth angles in opposite directions; and a second reproducing head 2R, and the pair of recording rotary heads 1W, 2W.
On the other hand, the first reproducing head 1R is
The recording head 1W and the second reproducing head 2R are arranged at positions scanning the same recording track as the second recording head 2W, and the first reproducing head 1R is 2nd above
The recording head 2W and the second reproducing head 2R each have the same azimuth angle as the first recording head 1W,
A pair of reproducing rotary heads 1R, 2R that scan the surface of the magnetic tape 3 to reproduce signals; and a pair of recording rotary heads 1W, 2W and The reproducing rotary heads 1R, 2R are coupled to the tape guide drum 4 so as to face in the outer radial direction, and control inputs supplied from an external electronic circuit control at least the recording rotary heads 1W, 2W. and the above-mentioned reproducing rotary heads 1R, 2R.
The parts to which are attached are the recording rotary heads 1W, 2W and the reproduction rotary heads 1R, 2R.
A plurality of electromechanical transducers 7, 31, and 32 are individually and independently displaced in a direction perpendicular to the respective rotation planes, and the recording rotary heads 1W and 2W are used to transfer the magnetic tape onto the three surfaces of the magnetic tape. Pilot signal generators 12a, 12b, 12c, and 12d generate a plurality of types of pilot signals that are recorded together with the main signal and have different information characteristics between adjacent tracks; and the recording rotary heads 1W and 2W. Pilot signal detection circuits 18a, 18b, 18c, and 18d detect reproduction pilot signals from signals reproduced from the recording tracks of the magnetic tape 3, and record the information characteristics of the detected reproduction pilot signals as the main signal. A comparison is made between the track and its adjacent recording track, and the reproducing rotary head 1
Tracking error signal forming circuits 19, 24, 25e, 26e, 25f, 26f that form tracking error signals corresponding to the deviation amount and direction of the main signal from the recording track of R and 2R.
and control circuits 27, 28e, 28 that generate control inputs to be input to the electro-mechanical conversion elements 7, 31, 32 according to the tracking error signal.
An auto-tracking device for a magnetic recording/reproducing device characterized by a configuration comprising: f, 29, 30. 2 The pilot signal generating sections 12a, 12b,
12c and 12d are configured to generate a plurality of signals having different frequencies between adjacent tracks as pilot signals recorded on each recording track of the magnetic tape 3. Automatic tracking device for magnetic recording and reproducing devices. 3 The tracking error signal forming circuit 19,
24, 25e, 26e, 25f, and 26f include a frequency conversion means 24 in which tracking error signals of two constant frequencies are formed. Auto tracking device for recording and reproducing equipment. 4. The magnetic recording medium according to claim 1, 2 or 3, wherein the recording rotary heads 1W, 2W are arranged at positions that precede the reproducing rotary heads 1R, 2R in the rotational direction. Auto tracking device for recording and reproducing equipment. 5 The above-mentioned rotary heads for reproduction 1R and 2R are arranged so that the above-mentioned rotary heads for recording 1W and 2W are connected to each other, and the above-mentioned first reproduction head 1R is connected to the first recording head 1W and the second reproduction head 2R is connected to the first reproduction head 1R. The automatic magnetic recording and reproducing apparatus according to claim 1, 2, 3, or 4, wherein the recording heads 2W and the second recording head 2W are arranged so that the center lines of their head widths coincide with each other. tracking device. 6. The recording rotary heads 1W, 2W are configured such that the first recording head 1W and the second recording head 2W have different azimuth angles in opposite directions that are symmetrical with respect to the recording track direction. Claim 1, 2, 3, 4 or 5
An auto-tracking device for a magnetic recording and reproducing device according to paragraph 1.