JPS6152532B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION It is well known that various recording and reproducing methods have been proposed in the past in order to meet the demand for high-density recording of information signals on recording media.

Also, in a magnetic recording/reproducing device using a magnetic recording medium as a recording medium, for example, tracking control is applied to the magnetic head, or two magnetic heads for recording/reproducing are used so that the longitudinal direction of the magnetic gap is aligned with the recording medium. An angle smaller than the direction perpendicular to the direction of extension of the mark (e.g. ±6°, ±7°)
Various methods have been tried, such as using a so-called tilted azimuth method that eliminates the need for unrecorded areas (guard bands) between adjacent recording traces by using a recording medium that is tilted by an angle of . There is.

The applicant company has also made many proposals for various magnetic recording and reproducing methods or magnetic recording and reproducing devices that can successfully realize high-density recording, and has also made many proposals regarding their practical application. We have made many efforts. Now, driving and displacing the magnetic head under tracking control so that it follows the recording trace accurately is effective in stably reproducing good reproduction signals from the magnetic tape in the normal reproduction mode. Not only that, but in so-called trick play playback modes such as still playback and slow motion playback,
This is effective in stably reproducing good reproduction signals from magnetic tapes, but in magnetic recording and reproducing devices to which conventional general tracking servo systems are applied, tracking is limited to the number of magnetic heads. The configuration has become complicated because it is required to include a servo system.Therefore, for magnetic recording and reproducing devices where cost reduction is desired, such as home VCRs, conventional magnetic heads have not been used. In reality, tracking control was not performed.

However, recently, there has been a demand for home-use VCRs that can perform various types of trick play playback.
VTRs are also becoming available, but in many of these, the magnetic head cannot accurately follow the recording trace during trick play playback, so there are so-called so-called A reproduced image of good quality could not be obtained because bar noise or the like appeared or fluctuations occurred in the reproduced image.

As a solution to the above-mentioned problems, the applicant company first filed Japanese Patent Application Nos. 15348-1982 and 16821-1983.
No. 54-19986, etc., we proposed a magnetic head drive device with a simple configuration capable of tracking control drive of a magnetic head, a tracking system for a magnetic head, etc. To provide a magnetic recording and reproducing device that can easily obtain high-quality reproduced images free from image fluctuations and image fluctuations.

The present invention provides a magnetic head drive device in a rotating head type magnetic recording/reproducing device that is effectively used in implementing the previously proposed magnetic head tracking method. The specific contents will be explained in detail.

FIG. 1 shows a head drum assembly (sometimes referred to as a head drum assembly) that includes an embodiment of the magnetic head drive device in the rotary head type magnetic recording/reproducing apparatus of the present invention. Fig. 2 is a plan view of the upper drum seen from the bottom side so that the rotating member provided on the upper drum side is clearly shown, and Fig. 3 is a side view of the upper part as shown in Fig. 2. The exploded perspective view of the drum, Figures 4a, b, and 5a, b, etc. are the perspective view and side sectional view {Figure 5a} and front view {Figure 5b} of the component parts. be.

In the figure, reference numeral 1 denotes the rotation axis of the drum, and the rotation axis 1 of the drum is connected to the boss portion 2a and lower end portion 2b of the lower drum 2 (in the illustrated example, the lower drum 2 is configured as a fixed drum 2). It is supported by bearings 3a and 3b provided, and is driven and rotated at a predetermined rotational speed, for example, 1800 rpm, by a rotational driving force transmitted from a power source. A tape guide 4 is provided on a part of the outer surface of the fixed drum 2 for positioning the edge of the magnetic tape T.

5 is an upper drum (in the illustrated example, the upper drum 5 is used as the rotating drum 5),
The engagement protrusion 6a at the bottom of the bushing 6 is press-fitted into the center of the rotating drum 5, and the rotating drum 5 and the bushing 6 are firmly fixed by applying suitable fixing means. FIG. 4a is a perspective view of the bushing 6, and FIG. 4b is a perspective view of the rotating drum 5.
Fig. 4 is a perspective view of an engagement protrusion provided in the center hole 5a of the rotary drum 5 shown in Fig. 4b and at the center of the bottom of the bushing 6 shown in Fig. 4a. The part 6a (Fig. 4a shows the upper surface side of the bushing 6, so the engagement protrusion 6a at the bottom of the bushing 6 is not shown) is press-fitted, and the part 6a shown in Fig. 4b is press-fitted. When the bushing 6 shown in FIG. 4a is fixed to the rotating drum 5, the state shown in the lowermost part of FIG. 3 is obtained.

The fixed drum 2 and the rotating drum 5 are made of aluminum alloy, for example, and the bushings 6
is preferably made of a material with a certain degree of hardness.

A fixed drum 2 with a rotating shaft 1 loosely passing through the center.
A mounting portion 9 for a fixed winding of a rotating transformer (rotary transformer) is fixed on the inner bottom surface of the transformer, and one end of a coil winding frame 21 of a drive coil 22 is fixed. Reference numeral 10 denotes a mounting portion for the rotating winding of a rotary transformer. It rotates at high speed as the rotating shaft 1 rotates with a predetermined minute gap formed between it and the surface.

The fixed winding is wound around the fixed winding mounting part 9 which is in a stationary state, and the rotating winding is wound around the rotating winding mounting part 10 which rotates as the rotating shaft 1 rotates. Signal transmission between the windings and the windings is carried out well through the minute gaps mentioned above. 11a~
11d is a terminal of the fixed winding of the rotating transformer;
In addition, the rotating winding of the rotating transformer is connected to the rotating drum 5.
The magnetic heads 13a and 13b are connected to a relay terminal (not shown) provided on the outside of the upper part thereof, and connection wires to the windings of the magnetic heads 13a and 13b are also connected to the relay terminal.

The magnetic heads 13a, 13b are fixed to head brackets 12a, 12b made of non-magnetic material, and the head brackets 12a, 12b are
Although it is attached to the rotating member 15,
When installing the magnetic heads 13a and 13b,
The mounting positions of the head brackets 12a and 12b relative to the rotating member 15 are adjusted so that the head brackets 12a and 12b are positioned at a predetermined distance from each other on the center line of the rotating member 15.

The rotating member 15 is preferably made of a ferromagnetic material such as mild steel so that the two yoke parts 16a and 16b are integrally connected. An exemplary configuration of the rotating member 15 is shown in the longitudinal sectional side view of FIG. 1, the plan view of FIG. 2, and the exploded perspective view of FIG. 3. Rotating member 15 in the illustrated example
The yoke portions 16a, 16b have an inverted U-shape in longitudinal section, and an arcuate planar shape as shown in FIGS. 2 and 3. is a permanent magnet 17
a, 17b are provided.

Yoke parts 16a, 16b and permanent magnets 17a, 1
7b constitutes a DC magnetic field generator that is a part of a component for generating electromagnetic power for driving and displacing the rotating member 15 so as to tilt it, and the direction of magnetization of the permanent magnets 17a and 17b is The magnetic field having the required direction and orientation is applied to each yoke portion 16a, 1
6b, and in FIG. 2, each permanent magnet 17a, 1
The polarity of 7b is illustrated.

The rotating member 15 is rotated in such a manner that it can rotate integrally with the rotating shaft 1 (rotary drum 5) and that the angle formed between it and a plane perpendicular to the extending direction of the rotating shaft 1 can be changed. The rotating member 15 should be movably supported by the rotating shaft 1 or a component integrally formed with the rotating shaft 1, and the rotating member 15 according to the above-mentioned support mode in the illustrated configuration example. The supporting structure includes a center holder 1 fixed to a rotating member 15 and a bushing 6, respectively.
4 and the rotation fulcrum member 18.

That is, referring to FIGS. 1 to 3, the rotating member 15 has a center retainer 1 on its mounting surface 23.
4, and after fitting the center hole of the center holder 14 into the protrusion 6c of the bushing 6, the center hole 18c of the rotation fulcrum member 18 is fitted into the protrusion 6c of the bushing 6. Fittingly, the rotation fulcrum member 18, the center retainer 14, and the support surface 6 of the bushing 6
By fixing b, the rotating member 15 is integrally connected and fixed to the bushing 6 via the center holder 14, and the rotating member 15 is rotated on the pivot member 18. Tips P of the protrusions of the dynamic fulcrum parts 18a ₁ and 18a ₂ {Figs. 3 and 5
It is possible to perform rotational movements such that the angle formed between the extending direction of the rotary shaft 1 and a plane orthogonal to the plane perpendicular to the extending direction of the rotating shaft 1 can be changed using the rotating shaft 1 as a rotational fulcrum.

As the center holder 14, a thin plate made of an elastic material,
For example, a thin sheet of phosphor bronze may be used, and
It is desirable that the rotation fulcrum member 18 be made of a metal with high hardness.

The mounting surface 23 of the rotating member 15 and the outer peripheral edge of the center holder 14 are fixed together by the mounting surface 23 of the rotating member 15.
Screw holes 15S, 15T, 15 provided in
U, 15V, and holes 14S, 14T, 14U, 14V drilled in the outer peripheral edge of the center holder 14, screws 20, 20 (in FIG. 3, the screw 20 is 1 (Only a book is shown). Of course, the above-mentioned fastening may also be carried out by any other fastening means.

Moreover, the center retainer 1 fixed to the rotating member 15
4, the support surface 6b of the bushing 6, and the rotation fulcrum member 18 are fixed to each other through screw holes 6W, 6X, 6Y, and 6Z provided in the support surface 6b of the bushing 6.
and holes 14W, 14 bored in the center retainer 14.
X, 14Y, 14Z and holes 18W, 18X, 18Y, 18Z drilled in the rotation fulcrum member 18,
Screws 19, 19 (screw 1 in Figure 3)
9) (only one is shown).

The center retainer 14 fixed to the rotating member 15 is
The rotating member 15 is fixed to the bushing 6 with its inner peripheral edge being clamped to the support surface 6b of the bushing 6 and the disc-shaped portion of the rotational fulcrum member 18, so that the rotating member 15 is connected to the rotating drum 5 (rotating shaft It is clear that a one-body rotation can be performed.
Moreover, the rotation fulcrum part 18 in the rotation fulcrum member 18
The tips P and P of the protrusions a ₁ and 18a ₂ are connected to the magnetic head 1
By contacting the upper surface of the center holder 14 on the mounting surface 23 of the rotating member 15 near the perpendicular bisector of the straight line connecting 3a and 13b, the tips P and P of the protrusions are moved against the rotating member 15. It is also clear that the rotating member 15 provided on the rotating drum 5 side can act as a rotational fulcrum for the rotary drum 5 as described above.
In the DC magnetic field of the yoke parts 16a and 16b, the drive coil 22 provided on the fixed drum 2 side
is inserted (see Fig. 1), and a driving current is applied to the driving coil 22 which is wound in a cylindrical shape around a cylindrical coil winding frame 21 fixed to the bottom of the fixed drum 2. The rotating member 15 is the rotational fulcrum member 1
The tips P and P of the protrusions of the rotation fulcrum portions 18a ₁ and 18a ₂ in 8 are used as rotation fulcrums, and the drive coil 2 described above is
Due to the electromagnetic force generated between the rotating member 15 and the DC magnetic field in accordance with the polarity and magnitude of the drive current passed through the drive current, the direction and amount of inclination are determined according to the polarity and magnitude of the drive current. Make a rotating motion as shown.

It goes without saying that the above-mentioned rotational movement of the rotating member 15 is performed well even when the rotating member 15 is rotating integrally with the rotating drum 5. The weight of the rotating member 15 is balanced on both sides of its rotational fulcrum, and the driving force for rotating the rotating member 15 is applied near the left and right ends of the rotating member 15. Since the entire weight of the rotating member 15 can be considered to be concentrated at the rotational fulcrum, the weight of the rotating member 15 does not adversely affect the tracking characteristics of the tracking servo system.

A rotating member 15, in which two magnetic heads are arranged 180 degrees symmetrically with respect to the center of rotation, rotates every minute.
Since the fundamental frequency of the tracking control drive signal necessary for tracking control to make each magnetic head follow the recording trace in the state of 1800 rotations is 30 Hz, the tracking by the rotational movement of the rotating member 15 is 30 Hz. In order to perform good control, it is necessary that the resonance frequency of the mechanical vibration system consisting of the rotating member 15 and the center holder 14 is higher than 30 Hz, but the rotating member 15 has a mass of several tens of grams. It has been clarified that even if a mechanical vibration system is used, the mechanical vibration system consisting of the rotating member 15 and the center holder 14 can be easily made to have a resonance frequency higher than 30 Hz. There is.

In addition, the two yoke portions 1 in the rotating member 15
6a and 16b have permanent magnets 17a and 16b, respectively.
17b is provided, but the yoke portions 16a, 1
The leakage magnetic flux from 6b is transmitted to the magnetic heads 13a and 13b.
It is easy to configure the two yoke parts 16a and 16b so as not to have any adverse effect on the parts.

The rotating member 15 described so far has a DC magnetic field generator configured therein, and drives and rotates the rotating member 15 in cooperation with the DC magnetic field generated by the DC magnetic field generator. Since the drive coil 22 through which the drive current to generate the electromagnetic force to generate the electromagnetic force was provided on the fixed drum 2 side, the drive power to be supplied when driving the rotating member 15 for tracking control is as follows. Since the power is supplied to the drive coil 22 in a stationary state, a power supply means using a slip ring and a brush is not required in the drive power supply path for tracking control, and therefore the magnetic head drive has a simple configuration. The advantage is that the device is available.

Contrary to the configuration example described above, a power supply means using a slip ring and a brush is provided in the drive power supply path for tracking control,
A drive coil is attached to the rotating member 15 provided on the rotating drum 5 side, and driving power is supplied to the drive coil via a slip ring and a brush.
In addition, a DC magnetic field generator is provided on the fixed drum 2 side, and the rotating member 15 is connected to the rotating drum 5 (rotating shaft 1).
It is also possible to make a tilting movement about the rotational fulcrum while rotating as one unit with the rotating member 15. In this case, the weight of the rotating member 15 is reduced, so it is possible to perform a tilting motion over a wide frequency range. A magnetic head drive device exhibiting excellent responsiveness can be obtained.

Further, the driving force for rotating the rotating member 15 is
In addition to the electromagnetic force generated by the DC magnetic field generated by the DC magnetic field generator and the current flowing through the drive coil as in the examples described above, for example, electromagnetic force generated by the electrostrictive phenomenon can be used. A driving force may be generated, or a driving force generated by any other means may be used.

Now, the rotating drum 5 (rotating shaft 1) as shown above
The rotating member 15, which is designed to be able to perform rotational movements around a rotational fulcrum while rotating integrally with the main body, rotates in accordance with the driving power supplied from the tracking control system. The moving angle changes so that the magnetic heads 13a, 13b can follow the recording trace.

FIG. 6 shows how the two magnetic heads 13a and 13b attached to the rotating member 15 are commonly displaced and driven by one tracking control drive mechanism. This is a diagram for explaining the related structure of the rotating member 15 and the rotating shaft 1 shown in FIG.
The related structure of the rotating member 15 and the rotating shaft described with reference to FIGS. 15 is connected and fixed to the rotating shaft 1 by the center holder 14, and the tips P, P of the protrusions of the rotating fulcrum portion (rotating fulcrums P, P)
It is freely rotatable in the directions of arrows 27α and 28α.

When a driving force for rotation is applied to the rotating member 15 and the rotating member 15 rotates in the direction of the arrow 27α about the rotational fulcrums P, P, the magnetic heads 13a, 13b are the sixth
When the magnetic heads 13a and 13b are displaced as indicated by arrows 27a and 27b in the figure, and the rotating member 15 is rotated about the pivot points P and P in the direction of arrow 28α in the figure, the magnetic heads 13a and 13b are are respectively displaced as indicated by arrows 28a and 28b in the figure.

A magnetic head 1 that is displaced by a rotational movement of a rotating member 15 around rotational fulcrums P, P.
The direction of displacement of 3a and 13b is determined by the magnetic head 13.
The direction is perpendicular to the rotation locus 26S of the magnetic heads 13a and 13b.
The direction of displacement is indicated by arrows 27a and 27 in FIG.
b, and arrows 28a and 28b, the magnetic heads 13a and 13b are opposite to each other, and the magnetic heads 13a and 13b are located at the pivot points P and P of the rotating member 15.
At the same time as the rotation movement in , it is in a state in which it is displaced in the opposite direction.

When the pivot points P, P are provided near the perpendicular bisector of the straight line connecting the two magnetic heads 13a, 13b, the rotating member 15 supports the pivot points P, P. When the magnetic heads 13a and 13b rotate about the rotation center, the magnitude of the displacement generated in the magnetic heads 13a and 13b is equal to each other. In addition, the 6th
An arrow 25S in the figure indicates the direction of rotation of the rotating shaft 1.

Now, when using the so-called helical scan method,
The movement locus of the magnetic head drawn on the magnetic tape by the magnetic head diagonally traverses the magnetic tape T, as shown in FIG. In FIG. 7, two magnetic heads having different azimuth angles are attached to a head drum, and the recording traces formed on the magnetic tape T by the magnetic heads are shown. , the running speed of the magnetic tape T, the head
7 is a diagram showing an example of a recording trace pattern on a magnetic tape T when the diameter and rotation speed of the drum, the inclination angle θ of the recording trace, etc. are determined, and the recording trace pattern shown in FIG. When the tape T moves in the direction of arrow α in the figure and the rotating magnetic head moves in the direction of arrow β in the figure,
That is, the rotation direction β of the magnetic head is determined so that the relative linear velocity between the magnetic head and the magnetic tape is lower than the relative linear velocity between the magnetic head and the magnetic tape when the magnetic tape is stopped. It is a matter of the case.

The trajectories (or trajectories traced) drawn on the magnetic tape T by the two magnetic heads alternately contacting the running magnetic tape T are AT ₁ , AT ₂ in FIG. 7 for one magnetic head. If so, BT ₁ , BT ₂ . . . in Fig. 7 for the other magnetic head
It becomes...

By the way, when trick play is performed during playback, the running speed of the magnetic tape T is different from the running speed during normal playback, so the trajectory drawn by the magnetic head on the magnetic tape T during trick play is The inclination angle θ is different from that during normal reproduction.

For example, when the relationship between the running direction of the magnetic tape and the rotating direction of the magnetic head is as shown in Figure 7, if the running speed of the magnetic tape is made slower than the running speed during normal playback. In this case, the value of the inclination angle θ of the movement locus drawn by the magnetic head on the magnetic tape T gradually becomes smaller than the value of the inclination angle θ drawn by the magnetic head on the magnetic tape T during normal playback. When the running of the magnetic tape T is stopped (during still playback), the value of the above-mentioned inclination angle θ becomes the smallest.

Also, contrary to the above, if the magnetic tape is run at a faster speed than during normal playback, the value of the inclination angle θ of the movement trajectory drawn by the magnetic head on the magnetic tape will be different from the normal playback speed. During reproduction, the inclination angle .theta. of the movement trajectory drawn on the magnetic tape by the magnetic head as shown in FIG. 7 gradually becomes larger.

The relative relationship between the running direction of the magnetic tape T and the rotating direction of the magnetic head is opposite to that shown in Figure 7 (for example, the direction of arrow β in Figure 7 is opposite to that shown in Figure 7). In this case, as the running speed of the magnetic tape T is slower (faster) than the running speed during normal playback, the inclination angle θ of the moving trajectory drawn by the magnetic head on the magnetic tape increases. The value of becomes larger (smaller) than the value of the inclination angle θ of the movement locus drawn by the magnetic head on the magnetic tape during normal reproduction.

Even if the recording trace pattern on the magnetic tape has unrecorded areas (guard bands) between adjacent recording traces, the running speed of the magnetic tape may be lower than the running speed during normal playback. Is the inclination angle θ of the movement trajectory drawn by the magnetic head on the magnetic tape when it becomes slower or faster than the inclination angle θ of the movement trajectory drawn by the magnetic head on the magnetic tape during normal playback? , or decreases, is the same as the case already described with reference to FIG. 7, including the fact that it changes depending on the relationship between the running direction of the magnetic tape and the rotating direction of the magnetic head. It is.

In this way, the inclination angle θ indicated by the movement trajectory of the magnetic head changes as the running speed of the magnetic tape changes, so the recording recorded on the magnetic tape is adjusted to be suitable for playback in the normal playback mode. During trick play, in which tracks are played back at a tape running speed different from the tape running speed during normal playback, the movement locus of the magnetic head exhibits an inclination angle that is different from the inclination angle of the recorded tracks on the magnetic tape. This causes noise bars to appear in the reproduced image and deteriorates the quality of the reproduced image.

The noise bars that occur in the reproduced image during trick play can be removed by allowing the magnetic head to accurately trace the recording traces on the magnetic tape. This can be achieved by driving and displacing each magnetic head under control and making each magnetic head accurately follow the recording trace that it was originally supposed to follow. It is well known that attempts have been made to perform reproduction by driving displacement under tracking control, but in the conventional tracking method of magnetic heads, each of the two magnetic heads is individually Since it was equipped with a tracking control drive mechanism, the configuration of the tracking servo system was complicated, and therefore it needed to be inexpensive, for example, for home VTRs, etc. As such, it is difficult to implement the tracking control method, and the performance of the drive mechanism itself for tracking control is also unsatisfactory, and improvements have been desired.

Now, in the magnetic head driving device in the rotating head type magnetic recording/reproducing apparatus of the present invention explained with reference to FIGS. A rotating member such as the one shown in FIG. The rotary member is rotatably supported by the rotary support portion so that the angle formed between the plane containing each magnetic head and the plane orthogonal to the extending direction of the rotating shaft can be changed when the rotary member is rotated. When a driving force is applied by the tracking control drive mechanism, the rotary member rotates and rotates around its rotary support portion, thereby making it possible to A magnetic head drive device that satisfactorily solves the problems of the conventional magnetic heads by allowing a tracking control drive mechanism to perform drive displacement operations for tracking control on two magnetic heads at the same time. The driving power supplied to the tracking control drive mechanism to provide the driving force for rotating the rotating member 15 is
By supplying the signal from a closed-loop tracking control circuit or from an open-loop tracking control circuit, it is possible to easily perform a good tracking control operation despite the simple configuration.

When performing open-loop tracking control during trick play using the magnetic head drive device of the present invention, the magnetic head drive device has the same repetition period as the rotation period of the rotary member 15 and one rotation of the rotary member 15. By applying a drive power to the tracking control drive mechanism that shows a waveform in which the drive power gradually increases and then gradually decreases (or gradually decreases and then gradually increases) within a certain period of time, However, in this case, the amplitude of the driving power described above is set to an appropriate value corresponding to the running speed of the magnetic tape.

The above-mentioned waveform of the drive power to be supplied to the tracking control drive mechanism during trick play is different from that during still playback and slow motion playback.
The waveform of the driving power during slow motion playback has the same polarity as that during still playback, and the waveform of the drive power during slow motion playback has the same polarity as that during still playback. The waveform is a superimposed rectangular wave having a period corresponding to the ratio and an amplitude corresponding to the slow motion ratio.

Furthermore, when performing closed-loop tracking control during trick play using the magnetic head drive device of the present invention, a waveform similar to that supplied during the open-loop tracking control described above is supplied to the tracking control drive mechanism. Even if the driving power is given to the tracking control drive mechanism and the drive power is given to the tracking control drive mechanism based on the tracking error signal generated by the closed-loop tracking control system, or to the tracking control drive mechanism, Only the driving power based on the tracking error signal generated by the closed-loop tracking control system and the necessary kick pulses may be provided.

The waveform of the drive power to be supplied to the tracking control drive mechanism during slow motion reproduction in the open-loop tracking control operation described above is as follows:
It is desirable to use one to which a damping pulse is added.

Furthermore, the phase of the drive power to be applied to the tracking control drive mechanism during trick play is adjusted in accordance with the response characteristics of the part that performs rotational movements by application of the drive power. Needless to say, it is desirable to be there.

Incidentally, in a magnetic recording/reproducing device, in order to ensure tape compatibility, it is important to mount the rotary head at a reference height, and any deviation in the absolute mounting height immediately results in a deviation in the recording trace. So,
When playing back a tape recorded on another machine when there is a deviation in the absolute height of the rotating head from the reference guide position, the relative phase of the disk motor with respect to the control pulse position is variably adjusted using a so-called tracking volume. Adjustment has traditionally been carried out.

However, in a magnetic recording/reproducing device that uses two rotating heads, the relative mounting height alignment between the two magnetic heads is determined by the initial mechanical setting conditions, and the The pattern of recording marks formed on the magnetic tape is determined by the relative installation height between the heads, so when considering machine compatibility (tape compatibility),
High precision is required for adjusting the relative mounting height between the two magnetic heads.

Incidentally, the production standards for so-called VHS magnetic recording and reproducing devices produced by the applicant's company stipulate that the allowable range of relative installation height deviation between two magnetic heads is within 3 μm ( Standards for equipment with a track pitch of 58 μm and a playing time of 2 hours).

In this way, in a magnetic recording/reproducing device that uses two rotating heads, a high degree of precision is required in the relative installation height between the two magnetic heads in order to ensure tape compatibility. Needless to say, this is exactly the same even when the two magnetic heads are driven and displaced in the width direction of the recorded trace for tracking control. Like a magnetic head drive 2
When the two magnetic heads 13a and 13b are attached to the rotating member 15 which is rotatably driven around a rotational fulcrum by a tracking control drive mechanism, the relative relationship between the two magnetic heads 13a and 13b is In order to accurately match the mounting height and maintain that accuracy during operation,
Some special means are required, and the patent application filed in 1973 by the applicant company
In the magnetic head drive device of No. 15348, a damper member made of, for example, rubber is brought into pressure contact with a plurality of locations on the upper surface of the rotating member 15, and the rest position of the two magnetic heads attached to the rotating member 15 is controlled. The relative height of the magnetic heads 13a and 13b can be adjusted, and the rotating member
A mechanical resistance element was added to the mechanical resonance system of No. 5.

However, in order for the tracking control operation to be performed satisfactorily by the rotational movement of the rotating member 15, the damper member that is in pressure contact with the rotating member 15 must be
Although it is necessary to perform a linear compression and expansion operation within the range of displacement associated with the rotational movement of the rotating member 15, the linear compression and expansion operation is performed over a wide range of displacement. The damper member that can be used is difficult to obtain, and the rotary member 15
When the damper member performs a large amplitude displacement operation for tracking control, the damper member does not return to its original state, and as a result, the two magnetic heads 13a and 13b
There is a risk that the relative installation height of the product may be incorrect, and an improvement measure was requested.

The present invention does not employ the method of adjusting the relative mounting heights of two magnetic heads using a damper member, which has been problematic in the past, but rather allows the two magnetic heads 13a and 13b attached to the rotating member 15 to be adjusted relative to each other. By supplying the required DC bias power to the drive power supply unit for rotationally driving the rotating member 15, the conventional problems can be solved. In addition, the stability of the operation of the magnetic head drive device can be significantly improved by supplying the above-mentioned DC bias power.

As already mentioned, in the magnetic head drive device of the present invention, the rotating member 15 to which the two magnetic heads are attached rotates when a driving force is applied thereto to rotate it. As shown in Fig. 6, while rotating integrally with the rotating shaft 1, the arrows 27 and 28 rotate around the pivot point P.
The two magnetic heads 13a, 13b are rotated in the direction of arrows 27a, 27b, or 2.
8a and 29b, the structure generates a driving force to cause the rotating member 15 to rotate as shown in the directions of arrows 27 and 28. When DC power having the required polarity and magnitude is supplied to the part, the rotating member 15 will be tilted in the direction and displaced around its rotational fulcrum P in accordance with the polarity and magnitude of the DC power described above. It is clear that it slopes to indicate the amount.

In the above operation, the rotational driving force of the rotating member 15 is
Even in the case of electromagnetic force generated by direct current power being supplied to a drive coil placed in a magnetic field, or by direct current power being supplied to an electrostrictive material. There is no difference even in the case of a driving force caused by a distortion phenomenon.

By the way, when the rotating member 15 is rotated about the rotational fulcrum P by applying a driving force for rotational movement to the rotating member 15 as described above, the 2 magnetic heads 13
If one of a and 13b is displaced upward (downward) by a certain displacement amount δ, the other one is displaced downward (upward) by a displacement amount δ equal to the displacement amount δ described above. The displacement amount δ corresponds to the magnitude of the rotational driving force applied to the rotating member 15, that is, the magnitude of the DC power supplied to generate the rotational driving force. By adjusting the DC power for generating the dynamic driving force, the relative heights of the two magnetic heads can be adjusted and set.

The relative installation height of the two magnetic heads in the magnetic head drive device of the present invention can be adjusted by, for example, reproducing an alignment tape (a standard tape recorded by a standard machine) and checking the state of the reproduced image. While observing the waveform of the reproduced high-frequency signal, the relative position of the two magnetic heads attached to the rotating member 15 can be adjusted by increasing or decreasing the DC power for generating the rotational driving force to be applied to the rotating member 15. The installation height can be easily and highly precisely adjusted to within ±3 μm, which is defined as the required mechanical accuracy in production.

The two magnetic heads 13a and 13b attached to the rotating member 15 are adjusted to a specified state as their relative mounting height by the adjustment DC power supplied to the tracking control drive mechanism. Therefore, the DC power that was supplied to the tracking control drive mechanism in that state is always supplied to the tracking control drive mechanism as DC bias power to provide a reference point for the operation of the tracking control drive mechanism. .

When the tracking control drive mechanism is configured such that the movable part is driven by electromagnetic force, the above-mentioned DC bias power may be expressed as a DC bias current supplied to the drive coil,
In addition, when the tracking control drive mechanism is configured such that the movable part is driven by a driving force caused by an electrostrictive phenomenon, the above-mentioned DC bias power is a DC bias applied to a bimorph mechanism using an electrostrictive material. It can also be expressed as voltage.

FIGS. 8a to 8f show a case where the rotating member 15 has two attached magnetic heads 13a and 13b, and the longitudinal directions of the magnetic gaps in the respective magnetic heads are different from each other (so-called In the case of a magnetic recording/reproducing device using a tilted azimuth method, how the waveform of the reproduced high-frequency signal changes when the magnitude of the DC power supplied to the tracking control drive mechanism is increased or decreased. This is an exemplary waveform diagram, and FIG. 9 is a diagram showing the correspondence between recording traces on the magnetic tape and two magnetic heads.

Referring to FIGS. 8a to 8f and FIG. 9, as the magnitude of the adjustment DC power supplied to the tracking control drive mechanism is increased or decreased, the two magnetic Head 13a,
How 13b is relatively displaced and how the waveform of the reproduced high frequency signal changes accordingly will be explained as follows.

Assume that the magnetic tape T shown in FIG. 9 is an alignment tape, and that A _t1 , A _t2 ...... in the figure
. . . is a recording trace to be reproduced by the magnetic head 13a, and B _t1 and B _t2 in the figure are recording traces to be reproduced by the magnetic head 13b. The head 13a accurately traces the recording trace A _t1 , and the magnetic head 13b traces the recording trace B _t1
In other words, the rotating member 1
Two magnetic heads 13a attached to 5,
13b, when their relative mounting heights are in the specified state, the waveform of the reproduced high frequency signal is the 8th
As shown in Figure A, the reproduced image also has good quality.

In FIG. 8b, the relative mounting heights of the magnetic heads 13a and 13b are as specified, but the magnetic head 13a is attached to both the recording trace A _t2 and the recording trace B _t2 in FIG. straddle each half, and
The two magnetic heads are sequentially reproduced in a state in which each of the two magnetic heads straddles a common recording trace by half (see Fig. 9), such that the magnetic head 13b straddles half _of both the recording trace B _t2 and the recording trace A t3. FIG. 4 is a waveform diagram of a reproduced high-frequency signal when performing this.

In Fig. 8c, the magnetic head 13b has a recording trace B _t3.
is also a waveform diagram of the reproduced high-frequency signal when the magnetic head 13a sequentially follows the recording trace A _t4 (see FIG. 9). Although the high-frequency signal has a sufficient signal level, unnaturalness is recognized in the motion of the reproduced image.

Next, FIG. 8d shows that when the relative mounting heights of the two magnetic heads are shifted by 1/2 track pitch compared to the specified state, one of the magnetic heads 13a is attached to the recording trace A _t3 . The other magnetic head 13b deviates from the correct tracking state by 1/2 track pitch and is on each of the recording traces A _t3 and B _t3 by 1/2, and the reproduced high frequency from the magnetic head 13b is When the signal level of the signal is set to 1/2 of the signal level of the reproduced high frequency signal from the magnetic head 13a (9th
FIG. 3 is a waveform diagram of a reproduced high-frequency signal (see figure).

FIG. 8e is a waveform diagram of the reproduced high-frequency signal when one of the two magnetic heads is completely on the reverse track, and FIG.
The figure is a waveform diagram of the reproduced high-frequency signal when the magnetic head 13a rides on the recording trace A _t2 and the magnetic head 13b rides on the recording trace B _t3 in order to follow the recording traces in sequence.

Although the reproduced high-frequency signal in the state shown in FIG. 8f has a sufficient signal level, the reproduced image has unsatisfactory continuity of motion.

In this way, the two magnetic heads 13a, 13b
Since the waveform of the reproduced high-frequency signal and the state of the reproduced image change depending on how it rides with respect to the recording trace on the magnetic tape, playback using an alignment tape is necessary. By adjusting the magnitude of the DC bias power supplied to the tracking control drive mechanism while performing the operation so that the signal level of the reproduced high-frequency signal is at its maximum and the reproduced image is in a good condition. , it is clear that the relative heights of the two magnetic heads can be set correctly in a defined manner.

Rotating member 1 for tracking control drive mechanism
By supplying DC bias power to the drive coil 22 while DC bias power is being supplied to correctly set the relative heights of the two magnetic heads attached to the drive coil 22 to a specified state. As described above, the rotating member 15 rotates around the rotational fulcrum and tilts, but the rotating member 15 in this state cannot be applied with DC bias power as long as the DC bias power continues to be supplied. Therefore, when a tracking control drive signal is supplied to the tracking control drive mechanism superimposed on the above-mentioned DC bias power, In this case, the rotating member 15 is at a reference position based on the tilted position caused by the supply of the DC bias power mentioned above (the position when the drive signal for tracking control is zero).
As a result, rotational movements are performed depending on the polarity and magnitude of the drive signal for tracking control.

As mentioned above, when the DC bias power is supplied to the tracking control drive mechanism, the rotating member 15 is moved by the center holder 14 having a relatively small stiffness at its rotational fulcrum position.
As the rotation member 1 is deformed, the entire body is tilted to the reference position, and in this state, the rotating member 1
5 has a large mechanical impedance with respect to driving forces other than the driving force of the tracking control drive mechanism because the above-mentioned DC bias power is supplied to the tracking control drive mechanism and the tracking control drive mechanism is rotationally driven. Therefore, even if a driving force other than the driving force by the tracking control drive mechanism is applied to the rotating member 15, the rotating member 15 maintains the reference position set by the supply of DC bias power. Therefore, even if an external force other than the driving force from the tracking control drive mechanism is applied to the rotating member 15, there will be almost no change in the relative mounting heights of the two magnetic heads. .

In this way, by supplying DC bias power to the tracking control drive mechanism, the rotating member 15 can maintain its reference position, that is, the relative movement of the two magnetic heads can be controlled. Since the state in which the mounting position is fixed can be maintained stably, the two mounted on the rotating member 15 can be
The relative mounting heights of the magnetic heads 13a and 13b are intentionally deviated from the specified state by, for example, about 50 to 100 μm, and DC bias power is supplied to the tracking control drive mechanism. Therefore, by correcting the above-mentioned deviation, there is an advantage that the relative mounting positions of the two magnetic heads are set in a prescribed state, and that state is stably fixed and maintained. It will be done.

When no DC bias power is applied to the tracking control drive mechanism, the two magnetic heads 13 attached to the rotating member 15
Even if the relative mounting heights of a and 13b deviate significantly from the specified state, for example by several track pitches or more, the two magnetic The relative mounting heights of the heads can be adjusted, and in this case, the relative mounting positions of the two magnetic heads remain stably fixed in a specified state. However, when a large deviation from the specified state is corrected by supplying a large DC bias power as in this case, the reference position set by the correction described above is changed to a position with a large inclination of the rotating member 15. Since the operating range of tracking control that should be performed in both positive and negative directions around the reference position is different for each direction, good tracking control is achieved. From the point of view of expected operation, the reference position of the rotating member 15 when the relative mounting heights of the two magnetic heads are adjusted to a specified state is obtained when the rotating member 15 is in a large inclination state. It is not desirable to be there.

As mentioned above, the two magnetic heads 13a, 13
b is attached to a rotating member 15, and the rotating member 15 rotates about a rotational fulcrum when driving power is supplied to the tracking control drive mechanism, and the two magnetic heads 13a and 13b are rotated magnetically. In the case where the drive is adapted to be displaced in the width direction of the recorded trace on the tape, when a large drive power is supplied to the tracking control drive mechanism for some reason, the rotating member 15 tilts greatly, and as a result, The two magnetic heads are displaced with large amplitude in the width direction of the recording trace on the magnetic tape.

However, the magnetic heads 13a and 13b do not operate on the rotating drum 5 in the gap between the rotating drum 5 and the fixed drum 2.
Since the magnetic heads 13a and 13b rotate as the magnetic heads rotate, when the displacement amount of the magnetic heads 13a and 13b is larger than the gap size between the rotating drum 5 and the fixed drum 2, the magnetic heads rotate between the rotating drum 5 and the fixed drum 2.
The magnetic heads 13a, 13b may be damaged due to collision with the edges of one or both of the magnetic heads. By the way, the magnetic head 13 due to the above-mentioned reason
In order to prevent damage to aa and 13b, a solution was taken in which the gap between the rotating drum 5 and the fixed drum 2 was significantly increased to allow for large-amplitude displacement of the magnetic head. Such a solution is adopted because, in some cases, the magnetic tape sinks into the wide gap formed between the drum 5 and the stationary drum 2, worsening the contact between the magnetic tape and the magnetic head. I can't.

Therefore, in the magnetic head drive device of the present invention, damage to the magnetic heads 13a and 13b can be prevented by limiting the amount of inclination of the rotating member 15 using a stopper. The stopper may be, for example, a screw 24 screwed into the bottom of the rotating drum 5, as shown in FIGS. 1 and 3.
a, 24b may also be used. In short, the stopper for limiting the amount of displacement of the rotating member 15 only needs to have a structure that can limit the amount of displacement of the rotating member 15.
As shown in FIG.
Or, for example, as shown in FIG.
From the side of A, 15B, the connecting portion 15A,
15B may be provided on the side of the rotating drum 5 and used as the stopper 26.

FIG. 11 is a block diagram showing a schematic configuration of a tracking control system (tracking servo system), a disk servo system, a capstan servo system, etc. In this figure, 27 is an operation mode control circuit, and 28 is a tracking control drive signal generation circuit,
29 is a capstan servo circuit, 30 is a reference oscillator, Mc is a capstan motor, 31 is a capstan, PGc is a pulse generator, 32 is a pinch roller, 33 is a control head, 34 is a disk servo circuit, Md is a drum motor , 35 is a rotary transformer, PG ₁ and PG ₂ are tone wheel pulse generators that cooperate with the magnet M, 36 is a flip-flop, 37 is a preamplifier, 38 is a switching circuit, 39 is a video signal output circuit, and 40 is an adder circuit. The capstan servo circuit 29 operates according to the control signal given from the operation mode control circuit 27.
By changing the frequency division ratio with respect to the reference signal supplied from the reference oscillator 30, a reference signal with a predetermined frequency value according to the operation mode is obtained, and the reference signal and the control signal reproduced by the control head 33, The capstan motor Mc is activated by the pulse signal generated by the pulse generator PGc.
is the predetermined rotation speed depending on the operating mode, i.e.
A control operation is performed so that the running speed of the magnetic tape by the capstan 31 becomes a predetermined running speed according to the operation mode.

Furthermore, for the capstan servo system including the capstan servo circuit 29 described above,
Tracking control drive signal generation circuit 28 to be described later
A part (or all) of the tracking control drive signal is applied from the magnetic tape so that the running speed of the magnetic tape is changed according to the tracking control drive signal.
If the tracking control drive mechanism can always operate with its center of operation located near the center of its movable range when the magnetic head is in a state where it shows the correct correspondence with the recorded trace, the cumulative error can be reduced. As a result, it is possible to effectively prevent the operating center position of the tracking control drive mechanism from deviating from the center of the movable range. It is a desirable embodiment to control the running speed of the magnetic tape by applying some or all of the magnetic tape.

The drum motor Md is a disk servo circuit 34
The number of rotations is controlled by the rotating drum 5, and the rotating drum 5 is rotated at a predetermined number of rotations. In the illustrated example, the disk servo system includes a disk servo circuit 34
However, it is shown that a configuration is used in which a predetermined operation is performed using the tone wheel pulse generated by the tone wheel pulse generator PG ₁ and the reference signal generated by the reference oscillator 30.
Of course, the disk servo system may be constructed using disk servo circuits having other configurations.

A rotating member 15 that rotates integrally with the rotating drum 5
Two magnetic heads 13a, 13b attached to
The reproduced signal from the preamplifier 37 is supplied via a rotary transformer 35 to a preamplifier 37, where it is amplified and then supplied to a switching circuit 38. A switching pulse for controlling switching of switching circuit 38 is provided from flip-flop 36. The flip-flop 36 is triggered by the tone wheel pulses S 1 , S ₂ outputted from _the tone wheel pulse generators PG ₁ , PG ₂ and rotates the rotating drum 5 .
generates a rectangular wave pulse Ps having the same rotation period as the rotation period of the rotating member 15 (rotation period of the rotating member 15) and supplies it to the above-mentioned switching circuit 38, and also sends it to the tracking control drive signal generation circuit 28 via the addition circuit 40. give to

Figure 12a is the vertical synchronizing signal Pv, Figure 12b is
The figure shows the tone wheel pulses S ₁ and S ₂ , and the figure 12c shows the output square wave pulse from the flip-flop 36.
Ps. The switching circuit 38 performs a switching operation using the rectangular wave pulse Ps supplied from the flip-flop 36 as a switching pulse Ps, and generates a magnetic signal that is tracing the recording trace of the magnetic tape T in the two magnetic heads. Only the reproduction signal from the head is applied from the preamplifier 37 to the video signal output circuit 39 and the tracking control drive signal generation circuit 28.

The video signal output circuit 39 performs necessary signal processing and sends the video signal accompanied by audio to the subsequent circuit. Further, the reproduced high frequency signal given from the switching circuit 38 to the tracking control signal generation circuit 28 is subjected to envelope detection to extract its amplitude fluctuation component, and the alternating current component is used for tracking control. Alternatively, for example, a reference signal for tracking control included in the reproduced signal is extracted, and a tracking control drive signal is generated therefrom to be used for tracking control.

Next, the rectangular wave pulse Ps (Fig. 12, c) outputted from the flip-flop 36 and given to the tracking control drive signal generation circuit 28 is used to generate a triangular wave St (Fig. 12, d) for tracking control. used for. The phase of this triangular wave St is
As described above, it should be set appropriately depending on the response characteristics of the mechanical system including the rotating member 15.

In the tracking control drive signal generation circuit 28,
Based on the rectangular wave pulse Ps supplied from the flip-flop 36, a triangular wave as shown in FIG.
St (triangular wave can be easily obtained by integrating the rectangular wave pulse Ps. In addition, changing the phase of the triangular wave St can be easily achieved by changing the phase of the rectangular wave pulse Ps. There is a delay circuit using a monostable multivibrator,
(which can be easily constructed by combining a flip-flop with a square wave pulse generation circuit), then create a tracking control drive signal having the required polarity and magnitude according to the operation mode, and use it for tracking control. In the illustrated example, the output signal from the tracking control drive signal generation circuit 28 is applied to the drive coil 22.
It is supplied to

Tracking control drive signal generation circuit 2 described above
8 is also equipped with the aforementioned DC bias power supply source and DC bias power adjustment function, and adjusts the required DC bias power according to the information regarding the operation mode given from the operation mode control circuit 27. is sent to the tracking control drive mechanism, and the tracking control drive signal generation circuit 28 has the necessary signals to obtain tracking control drive signals with required waveforms according to various operation modes. Needless to say, it includes a pulse generation source having a waveform, period, magnitude, etc., a waveform shaping circuit, an adjustment circuit, and the like.

FIG. 12e shows tracking control drive when the tracking control drive signal is given to the tracking control drive mechanism from the tracking control drive signal generation circuit 28 to perform open loop tracking control when the operation mode is the still image playback mode (still playback mode). Signal P
This is a waveform example diagram of _st , and the tracking control drive signal P _st shown in this twelfth figure is obtained when the response characteristics of the tracking control drive mechanism are good (when the delay is 0).
{This point is also the same in the case of FIGS. 12 h to 12 j, which will be described later}.

By the way, when performing open-loop tracking control, it is necessary that the magnetic head correctly corresponds to the starting edge of the recording trace, but this requires, for example, the magnetic head recorded on the magnetic tape T. By using the control pulse Pc recorded in a predetermined positional relationship with respect to the recorded trace, each of the two magnetic heads can individually detect the beginning of the recorded trace to be reproduced. It can be made to correspond correctly to the position. That is, the tracking control drive signal when performing open loop tracking control is transmitted from the magnetic tape T to the control head 33.
It is often generated with reference to the time position of the control pulse Pc reproduced by, for example,
The control pulse Pc shown in FIG. 12f triggers a monostable multivibrator that can generate a pulse with a pulse width of one vertical scanning period (1V period), and converts the output pulse of the monostable multivibrator into a gate pulse. The vertical synchronizing pulse Pv shown in FIG. 12a is extracted by a gate circuit that opens and closes as shown in FIG. It is better to create a tracking control drive signal that can be traced.

Note that when the playback mode is set to still playback mode, the playback signal is played back from the recording trace while the magnetic tape T is stopped; Of course, the control pulse Pc cannot be obtained, so when the playback mode is set to the still playback mode, at least one control pulse Pc is played back after, for example, a change operation to the still playback mode is performed. The magnetic tape T is run (moved) as shown in FIG. It is preferable to control the capstan motor Mc so that the magnetic tape is stopped in a state in which the magnetic tape corresponds to the magnetic tape correctly.

The tracking control drive signal shown in FIG. 12h is a waveform example diagram when the slow motion ratio is 3:1 as described above, but in this case, the tracking control drive signal shown in FIG. } A waveform in which a triangular wave having the same period and the same polarity as the triangular wave used during still playback shown in Figure 12e is superimposed on a rectangular wave having a repetition period three times that of }, and a damping pulse Pd is superimposed thereon. This is used as a tracking control drive signal.

Generally, the tracking control drive signal when the slow motion ratio is n:1 performed in an open loop is a rectangular wave with a period n times that of the rectangular wave pulse Ps shown in FIG.
The waveform is obtained by superimposing a triangular wave having the same period and the same polarity as the triangular wave shown in FIG. 2e and the damping pulse Pd. As the slow motion ratio increases, the amplitude (wave height value) of the triangular wave superimposed on the aforementioned rectangular wave is made smaller than the amplitude of the triangular wave used during still playback. The tracking control drive signal during slow motion playback that indicates the value is:
A square wave simply superimposed with a damping pulse Pd may also be used.

Note that the ACO-ACO line in FIG. 12h indicates the reference level in a state where the DC bias power described above is applied.

Figure 12i is an example of the waveform of the tracking control drive signal when playback in the fast-forward playback mode is performed under tracking control in an open loop. A triangular wave is used that has the opposite polarity to the triangular wave used during playback and has the same period as the triangular wave used during still playback.
The amplitude is changed according to the fast forward rate. The double-headed arrow shown in the vertical direction in the figure indicates that the amplitude is variable according to the fast-forward ratio.

FIG. 12J is an example of the waveform of the tracking control drive signal when playback in the fast rewind playback mode is performed under tracking control in an open loop, and shows the waveform of the tracking control drive signal in this case. is a triangular wave having the same polarity and same period as the triangular wave used during still reproduction, and its amplitude is changed according to the fast rewind ratio. The double arrows shown in the vertical direction in the figure indicate that the amplitude is made variable according to the fast reversal ratio.

The tracking control drive signal used for trick play during the open-loop tracking control operation described with reference to the waveform diagram in FIG. The signal is then applied to the tracking control drive circuit.

When tracking control is performed in a closed loop, the tracking control drive signal as shown in FIG. As mentioned above, it may be supplied to the mechanism. In this case as well, DC bias power is superimposed on the signal.

In the case where the tracking control drive mechanism is provided with only driving power based on a tracking error signal generated by a closed-loop tracking control system and required kick pulses to perform tracking control, for example, -21529, Japanese Patent Application No. 53-162734, and many other previously proposed closed-loop tracking control systems can be applied.

As is clear from the detailed explanation above, the magnetic head drive device of the present invention rotates integrally with the rotating shaft and performs a rotational movement that is inclined with respect to the extending direction of the rotating shaft. The rotary member 15, which is adapted to be able to rotate, is
The relative mounting heights of the two magnetic heads 13a and 13b, which are mounted at 180-degree symmetrical positions, can be adjusted to a specified state by adjusting the DC bias power supplied to the tracking control drive mechanism. It is possible to easily provide a magnetic recording and reproducing device with excellent tape compatibility, and
By constantly supplying the above-mentioned DC bias power to the tracking control drive mechanism,
The relative mounting heights of the two magnetic heads are stably fixed so that the rotating member 15 exhibits a large mechanical impedance when a driving force other than the driving force from the tracking control drive mechanism is applied to it. In a magnetic recording/reproducing device using the magnetic head drive device of the present invention, it is an object to provide an inexpensive device that can obtain reproduced images of good quality without noise bars during trick play. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view of one embodiment of the magnetic head drive device of the present invention, FIG. 2 is a plan view of a rotating drum equipped with a rotating member, FIG. 3 is an exploded perspective view of the same, and FIGS. Figure b is a perspective view of the bushing and the rotating drum, Figures 5a and b are longitudinal cross-sectional views {Figure a} and front view {Figure B} of the rotational fulcrum member, and Figure 6 is a diagram showing the rotation of the rotating member. Figures 7 and 9 are explanatory diagrams showing recording trace patterns, Figures 8a to 8f are waveform diagrams of reproduced high-frequency signals, and Figures 10a and b are modified examples of the stopper. FIG. 11 is a block diagram of the main part, and FIG. 12 a to i are waveform example diagrams. 1... Rotating shaft, 2... Fixed drum, 5... Rotating drum, 6... Bushing, 13a, 13b...
Magnetic head, 14... Center holder, 15... Rotating member, 16a, 16b... Yoke portion, 17a, 1
7b... Permanent magnet, 18... Rotating fulcrum member, 1
9, 20... Screw, 22... Drive coil, 24
a, 24b, 25, 26... stoppa, 27...
Operation mode control circuit, 28... Tracking control drive signal generation circuit, 29... Capstan servo circuit, 30... Reference oscillator, 31... Capstan, 32... Pinch roller, 33... Control head, 34... Disk servo circuit, 35...
...Rotating transformer, 36...Flip-flop, Mc
...Capstan motor, Md...Drum motor.

Claims (1)

[Claims] 1. Rotating members each having a magnetic head attached at a position 180 degrees symmetrical about the center of rotation are connected to a rotational power transmission system so that they can rotate at a predetermined number of rotations, and The rotation support part provided near the perpendicular bisector of the straight line connecting the magnetic heads allows the angle between the plane containing each magnetic head and the plane perpendicular to the extension direction of the rotation axis to be adjusted during rotation. The rotary member is rotatably supported so that it can be changed, and when a driving force is applied to the rotary member by the tracking control drive mechanism, the rotary member rotates while the rotary support portion of the rotary member rotates. In a magnetic head drive device of a rotary head type magnetic recording and reproducing device which is capable of performing rotational movements around a rotational member, a drive power supply unit in a tracking control drive mechanism that rotationally drives the above-mentioned rotating member. On the other hand, in a rotating head type magnetic recording and reproducing device, the magnetic head is equipped with means for supplying DC bias power to set the relative mounting height of two magnetic heads attached to a rotating member to a normal state. Head drive.