JPS6151331B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A rotary head type magnetic recording and reproducing device that is capable of recording and reproducing information signals through the relative movement of a rotating magnetic head and a magnetic tape has been used in the past. The number of magnetic heads is 1
It is well known that different configurations have been manufactured for individual, two-piece, and four-piece items, and that each type of item is put into practical use in its appropriate field of use. That's right.

In addition, in recent years, as there has been a strong demand for high-density recording and reproducing using recording media, so-called helical scan type rotary head magnetic recording and reproducing devices are also capable of high-density recording using magnetic tape. In order to realize reproduction, attempts have been made to implement tracking control on the magnetic head, to apply a so-called tilted azimuth method, and to employ various other means.

In addition, in order to realize high-density recording and reproducing on magnetic tape, the magnetic head was displaced under the operation of a tracking control system, so that the magnetic head correctly tracked each recording trace on the magnetic tape. In some cases, even when the magnetic recording/reproducing device is used in so-called trick play playback mode such as still playback or slow motion playback, it has the advantage of not producing noise bars in the reproduced image. can get.

Conventionally, in a rotary head type magnetic recording/reproducing device, when the magnetic head is displaced under the operation of a tracking control system, a drive mechanism that has been used as a tracking control drive mechanism for the magnetic head is, for example, disclosed in Japanese Patent Publication No. Publication No. 51-61815, Japanese Patent Application Laid-open No. 127210-1987, Publication No. 114311-1980,
As described in many other publications,
It used an electromechanical converter using a piezoelectric element. Electromechanical transducers based on piezoelectric elements are well-known bidirectional energy converters between pressure and electric charge, which can be applied to high dielectric constant materials such as anisotropic crystals such as barium titanate. , can be made by applying a high voltage of about 50KV/2.5cm for several minutes to polarize it. The piezoelectric element made in this way is a so-called bimorph plate, which is assembled into a cantilever shape and used as a drive mechanism.A magnetic head is attached to the tip of the piezoelectric element, and a voltage of about ±200 volts is applied to the bimorph plate. It is possible to give a displacement of about 0.5 mm to the magnetic head.

However, the bimorph plate used in the drive mechanism described above requires high voltage to drive the displacement of the magnetic head, as is clear from the example above, and the shape of the bimorph plate and the length from the fulcrum are It constitutes a mechanical resonant system with a high Q determined by the dimensions, etc., and the resonant system has drawbacks such as generating unnecessary vibrations due to disturbances.

Among the above-mentioned drawbacks, the fact that a high voltage is required to be supplied to the drive mechanism in order to drive the displacement of the magnetic head by the drive mechanism is difficult to overcome when the magnetic recording/reproducing device is used, for example, in a home VTR. is not desirable from the standpoint of risk prevention, and
The fact that the drive mechanism constitutes a mechanical resonance system with a high Q creates a problem in that it is extremely difficult to construct a stable servo system. A more specific explanation of the latter of the above-mentioned drawbacks is as follows.

In other words, the drive mechanism using a bimorph plate exhibits a high Q value of over 40 dB (100 times) when the resonance frequency of the mechanical resonance system is set to 400 to 500 Hz. A servo system including a drive mechanism using a bimorph plate becomes extremely unstable due to phase rotation. Therefore, if the drive mechanism used in the servo system is a bimorph plate,
For example, a bimorph plate may be used in which the Q value of its mechanical resonance system is reduced by adding a mechanical resistance element, or, for example, the displacement when the bimorph plate is driven may be It is necessary to apply solutions such as electrically damping the Q of the mechanical resonance system by detecting it with a piezoelectric element and applying electrical feedback to the bimorph plate based on the detection result. However, with the solution of using a mechanical damping member, there is a problem that the drive mechanism using the bimorph plate becomes less sensitive, or the selection of a damping member that can withstand acceleration of 1000G, and the problem of the damping member. There are problems with the mounting method, etc. On the other hand, the solution of applying electrical feedback to the bimorph board inevitably complicates the configuration, and also requires installation in the control power supply path. There are drawbacks such as the fact that the structure of the required power transmission means using slip rings and brushes becomes extremely complex as the number of magnetic heads increases.

Furthermore, since the driving displacement operation of the magnetic head by the bimorph plate is performed by the bending operation of the bimorph plate, the state of contact between the magnetic head and the magnetic tape deteriorates when the magnetic head is driven and displaced. This is also a drawback.

As described above, in a rotating head type magnetic recording and reproducing device in which information signals can be recorded and reproduced by the relative movement of the magnetic head and the magnetic tape, the magnetic head is moved orthogonally to its rotation locus. Conventional rotary head type magnetic recording/reproducing devices, which use a bimorph plate as a drive mechanism for driving displacement in the direction of movement, have the unavoidable drawback that the device is complicated and expensive. Aside from being implemented in rotary head type magnetic recording and reproducing devices for broadcasting services, for household VTRs that require low cost, a bimorph board is used as the drive mechanism for the magnetic head. cannot be adopted.

The present invention is a driving device for driving and displacing a magnetic head in a direction perpendicular to its rotation locus, and the supply of driving power to a driving device in a rotating state is achieved by a combination of a slip ring and a brush. To provide a magnetic head drive device for a magnetic recording and reproducing device that does not require the use of a power transmission means, which satisfactorily solves the problems in conventional magnetic recording and reproducing devices, and which enables high-density recording and reproducing. The magnetic head drive device in the magnetic recording and reproducing apparatus of the present invention, that is, the recording and reproducing of information signals by the relative movement of the magnetic head and the magnetic tape, will be described below. In a rotating head type magnetic recording/reproducing device that is capable of performing the following, a rotating member including a permanent magnet is provided on a rotating member to which at least a magnetic head is attached and is configured to be rotated at a predetermined speed. furthermore, a drive coil placed in the magnetic field generated by the DC magnetic field generator provided on the rotating member is provided opposite to the rotating member. A magnetic head drive device in a magnetic recording/reproducing device, in which the magnetic head is mounted on a fixed part fixed to the drive coil, and when a drive current is supplied to the drive coil, the magnetic head is driven and displaced in a direction perpendicular to the rotation locus of the magnetic head. The specific contents will be explained in detail with reference to the attached drawings.

FIG. 1 is a longitudinal cross-section of a head drum assembly (sometimes referred to as a head drum assembly) that includes an embodiment of a magnetic head drive device in a magnetic recording and reproducing apparatus of the present invention. 1 is a side view, and in this FIG. It is supported by a bearing 3 provided on a boss portion 2a of the structure.

Although only one bearing 3 is shown in FIG. 1, the rotating shaft 1 is supported by one other bearing not shown and the bearing 3 shown in the figure. It is driven and rotated at a predetermined rotational speed, for example, 1800 rpm, by the rotational power transmitted from the power source. A tape guide 4 is provided on a part of the outer surface of the fixed drum 2 to position the edge of the magnetic tape T.

5 is a rotating drum (in the example shown in the first figure, the upper drum 5 is used as the rotating drum 5); a pushing 6 is press-fitted into the center of the rotating drum 5, and the pushing 6 is connected to the rotating drum 5; 6 is firmly fixed by application of suitable fastening means. The fixed drum 2 and the rotating drum 5 are made of, for example, an aluminum alloy, and the pushing 6 is 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 part for the rotating winding of the rotary transformer, and this mounting part 10 is attached to the base plate 7 fixed to the rotating shaft 1, and the mounting part 10 is attached to the surface of the base plate 7 and the surface of the mounting part 9. The rotating shaft 1 rotates at high speed with a predetermined minute gap formed between the rotating shaft 1 and the rotating shaft 1.

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 above-mentioned minute gaps. 9a in the diagram
-9d are fixed windings, and 10a-10d are rotating windings.

11a to 11d are fixed windings 9a of the rotating transformer.
9d, and the rotating winding of the rotating transformer is connected to relay terminals 14a and 14b provided outside the upper part of the rotating drum 5. Magnetic heads 13a, 13b are connected to the relay terminals 14a, 14b.
The connecting wires of the windings are also connected.

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 illustrated in FIG. 1 has a main body portion and yoke portions 16a, 16b integrally made of a ferromagnetic material such as mild steel. Pushing from the center side 6
Screws 18a, toward holes 6a, 6b provided in
By inserting the tip of the screw 18b, it is pivoted by the tip of the screws 18a and 18b,
Both ends to which magnetic heads 13a and 13b are attached can be displaced in opposite directions.

The yoke portions 16a and 16b of the rotating member 15 have an inverted U-shape in longitudinal section in the example shown in the first drawing, and an arc-shaped planar shape as shown in the second drawing. Parts 16a, 16
Permanent magnets 17a and 17b are fixed to the side wall of b. Yoke parts 16a, 16b and permanent magnet 17
a and 17b constitute a DC magnetic field generating device that is part of a component for generating electromagnetic force for driving and displacing the rotating member 15 so as to tilt it.
The direction of magnetization of the permanent magnets 17a and 17b is selected so that a magnetic field having a desired direction and orientation is generated in a predetermined space in each yoke portion.
In the magnetic head drive device applied to the head drum assembly shown in FIG. 1, the permanent magnets 17a and 17b shown in FIG. -ing

When the pushing 6 of the rotating drum 5 is fitted onto the rotating shaft 1 and the pushing 6 and the base plate 7 are connected by the rotating drum set screws 8, 8..., the rotating drum 5 is integrally fixed to the rotating shaft 1. made with the state. Further, the rotating member 15 is constructed by inserting the tips of the screws 18a, 18b from the central side of the main body toward the holes 6a, 6b provided in the pushing 6, so that the tips of the screws 18a, 18b are connected to the rotation axis. 1, the aforementioned screw 18
Since the rotary member 15 is rotatably pivoted around the tips of a and 18b as fulcrums, the rotary member 15 rotates integrally with the rotary drum 5, which is integrally fixed to the rotary shaft 1. Screw 18a, 1
It is also possible to perform rotational movement using the tip of 8b as a fulcrum.

19a and 19b are damper members made of rubber, for example, and these damper members 19a and 19b are connected to the top surface of the rotating member 15 by screws 20a and 20b that are screwed into screw holes provided at the bottom of the rotating drum 5. (In the example shown in the first figure, the head bracket 12a,
12b) with a required pressure contact force. The damper members 19a and 19b have the function of regulating the static position of the rotating member 15 when it is not driven, adjusting the relative height of the magnetic heads 13a and 13b, and controlling the mechanical resonance system of the rotating member 15. It also has the function of adding a mechanical resistance element to suppress unnecessary vibrations of the rotating member 15. Note that the number of damper members 19a and 19b is not limited to two, and three or more damper members may be used, and the material of the damper members is selected so that it can simultaneously perform the two functions described above. It goes without saying that one should be selected that satisfies them.

Pushing 6 of the rotating drum 5 with respect to the rotating shaft 1
is inserted into the rotating drum set screw 8, 8.
In the state where the rotating drum 5 and the base plate 7 are integrally connected and fixed by..., in the DC magnetic field generated by the DC magnetic field generator provided on the rotating member 15, as a fixed part in a stationary state, A drive coil 22 mounted on the inner bottom surface of the existing stationary drum 2 is positioned in a non-contact manner with respect to the components of the DC magnetic field generator.

As shown in the plan view shown in FIG. 3, the drive coil 22 is a cylindrical coil winding frame 2.
1 and is placed in a DC magnetic field generated by a DC magnetic field generator provided on the rotating member 15, so that when a drive current is applied to the drive coil 22, it is in a fixed state. Due to the electromagnetic force generated between the current flowing through the drive coil 22 and the DC magnetic field in the DC magnetic field generator,
The rotating member 15 is rotated about the aforementioned fulcrum.

Since the rotating member 15 is driven and rotated integrally with the rotating shaft 1, the motion state of the rotating member 15 when the driving current is supplied to the drive coil 22 is the same as that of the rotating shaft 1.
While rotating integrally with the drive coil 2,
According to the electromagnetic force generated between the drive current supplied to 2 and the DC magnetic field generated by the DC magnetic field generator,
The magnetic heads 13a and 13b are tilted with respect to a plane perpendicular to the direction in which the rotating shaft 1 extends, and the magnetic heads 13a and 13b are thereby driven and displaced in a direction perpendicular to their rotation locus. .

Even when the rotating member 15 is rotating,
It goes without saying that the related structure of the drive coil 22 and the DC magnetic field generator should be determined so that the drive coil 22 and each component of the DC magnetic field generator maintain a non-contact state.

FIG. 4 shows how the rotating member 15 is driven and displaced when the magnetic head drive device applied to the head drum assembly shown in FIG. 1 applies a drive current to its drive coil 22. This is a diagram illustrating and explaining how the drive current flows through the drive coil 22, and the directions of the drive current flowing through the drive coil 22 are opposite to each other for the yoke parts 16a and 16b.
Since the directions and directions of the DC magnetic fields generated in the magnets a and 16b are the same, when a drive current is applied to the drive coil 22, the rotating member 15 moves to the fulcrum 18.
It is driven and displaced so that it is tilted around the center.

It goes without saying that the direction of inclination of the rotating member 15 is determined by the polarity of the drive current, and the amount of inclination is determined according to the magnitude of the drive current. 15U and 15D in FIG. 4 are exaggerated examples of the tilted state of the rotating member 15 when drive currents of different polarities are applied to the drive coil 22.

In this way, the rotating member 15, which is pivoted in the center of the main body, performs a seesaw action around the pivot point by the drive current supplied to the drive coil 22, and rotates one of the magnetic heads. When the magnetic head 13a is displaced downward in the figure, the other magnetic head 13b is displaced upward in the figure, and if the polarity of the drive current is reversed, the two magnetic heads 13
This shows a mode of displacement in which the direction of displacement of a and 13b is opposite to that in the above case.

This means that the two magnetic heads 13a, 13b
This gives rise to the advantage of being able to drive and control the tracking control system in common by one tracking control system.Especially when magnetic recording and reproducing is performed using the so-called tilted azimuth method using two magnetic heads, the still To obtain a reproduced image in good condition from a magnetic recording and reproducing device by operating a magnetic head drive device so as not to generate noise bars in the reproduced image even by open-loop control during playback and trick play such as slow motion reproduction. It also makes it possible.

It goes without saying that the DC magnetic field generator to be provided on the rotating member 15 should be constructed so that no magnetic flux leaks near the magnetic heads 13a and 13b, but if necessary, a magnetic field generator may be installed on the inner wall surface of the fixed drum 2. Measures such as providing a shield plate may also be taken.
Further, the permanent magnets 17a and 17b used may each have an arc shape as shown in the second figure, but for example, a large number of small permanent magnet pieces may be attached to the side walls of the yoke parts 16a and 16b. Alternatively, permanent magnets of other suitable shapes may be used. Yoke part 1
It is desirable that 6a and 16b have a continuous shape over a predetermined range, as in the example shown in the second figure, from the perspective of reducing the generation of leakage magnetic flux, but in practice In other words, it may be configured to have one or more notches.

FIG. 5 is a perspective view of the rotating member 15 described above with reference to FIGS. 1 and 2;
If this perspective view is also referred to, the above-mentioned rotating member 15
I believe that the structure and operation of the system will be better understood.

6 and 8 show other rotating members 15 that are configured to perform a seesaw action when the drive current of the drive coil 22 is supplied, similar to the rotating member 15 that performs a seesaw action shown in FIG. FIG. 7 is an exploded perspective view of the rotating member 15 shown in FIG. 6. FIG.

First, as is clear from the exploded perspective view of FIG. 7, the rotating member shown in FIG.
6b and a connecting portion 23, a center holder 24 attached to the connecting portion 23 of the main body, a holding fitting 25 used when attaching the center holder 24 to the main body, and a center holder 24. It is composed of a holding fitting 26 used when attaching the rotary shaft 1 to the rotating shaft 1, and pivot points 27 and 28.

The rotating member 15 shown in FIG.
The center retainer 24 and the retaining metal fittings 25 are sequentially placed on the upper surface 23U of the connecting portion 23 (the upper surface 23U is shown on the lower side in the figure), and the corresponding screw holes provided in each of the above-mentioned components are inserted. 23a, 24a, 2
5a, 23b, 24b...24d, 25d and attach the center retainer to the connecting portion 23 of the main body using screws 51, 51... (only one screw 51 is shown as a representative in the figure). 24 is fixed, and the rotating shaft 1 is inserted into the hole 29 in the center of the center holder 24.
After passing through the rotating shaft 1, the holding fitting 26 is passed through, and holes 26e to 2 provided in the holding fitting 26 are inserted.
6h and the holes 24e to 24h of the center holder 24, and fix them with screws 30, 30... (only one screw 30 is shown in the figure), and the tip of the screw 30. is screwed into the flange formed on the rotating shaft 1 to connect the rotating shaft 1 and the center holder 24.
By integrally connecting and fixing the rotating member 15 shown in FIG. 6, the rotating member 15 is rotated integrally with the rotating shaft.

Then, pivots 2 protruding from the base plate 7 are connected to two points j and k of the center holder 24.
By keeping the tips of the pivots 7 and 28 in pressure contact, the rotating member 15 can perform seesaw motion using the tips of the pivots 27 and 28 as fulcrums when a drive current is applied to the drive coil 22.

The rotating member 15 configured as shown in FIG.
In order to be able to perform a seesaw movement when a current is applied to the rotary member 15,
The direction of magnetization of the permanent magnets 17a and 17b is also the same as that of the rotating member 15 shown in FIG. 5 (the rotating member having the configuration already described with reference to FIGS. 1 and 2). There is no need to explain that this is necessary.

Note that in the rotating member 15 shown in the sixth figure,
Remove the pivots 27 and 28, and also remove the permanent magnet 1.
If the direction of magnetization of one of 7a and 17b is reversed from that shown in FIG. However, even if the rotating member 15 is made to make a piston movement in this way, the magnetic heads 13a and 13b cannot be moved in a direction perpendicular to their rotation locus. It is possible to drive displacement to.

FIG. 8 is a perspective view of an embodiment of the rotating member 15 configured to perform seesaw motion when a driving current is applied to the driving coil 22, and the rotating member 15 shown in the eighth figure has a cylindrical shape. The shaped side wall 50 and the annular bottom plate 31 together constitute a yoke part, and two semi-cylindrical permanent magnets 17a and 17b are mounted on the annular bottom plate 31.
However, the permanent magnets 17a and 17b are attached so that a slight air gap 32 and 33 is formed between the ends of each other.

A bottom plate 3 is provided on the inner circumference of the permanent magnets 17a and 17b.
1 is missing, and an opening is formed through which the rotating shaft 1 can pass. The yoke part is integrally made of a ferromagnetic material, for example, mild steel, and the direction of the DC magnetic field between the side wall 50 of the yoke part and the permanent magnet 17a and the direction of the direct current magnetic field between the side wall 50 of the yoke part and the permanent magnet 17b are determined. Each permanent magnet 17a, 17
In b, magnetization is applied to each of them.

34 and 35 are the permanent magnets 17a and 1 described above.
7b, which is provided in the spaces 32, 33 between the tips of the pivot holders 34, 35.
is a screw 18 inserted through the cylindrical side wall 50.
b, supports the tip of 18a.

The screws 18a and 18b are attached to the support fitting 3 whose bottom parts 36b and 37b are fixed to the bottom plate of the rotating drum 5.
Because they are screwed into screw holes 38 and 39 provided in the walls 36a and 37a of 6 and 37,
The rotating member 15 shown in FIG. 8 rotates integrally with the rotating drum 5 and is pivotally supported by screws 18a and 18b, so that when current is applied to the drive coil 22, the screws 18a and 18b are rotated. It is possible to perform seesaw motion using the tip as a fulcrum. In addition, in FIG. 8, the walls 36a, 37a of the support fittings 36, 37 are shown to clarify the structure.
Although shown as an exploded perspective view with a large distance between the cylindrical side wall 50 and the cylindrical side wall 50, in the actual rotating member 15, the wall portions 36 of the support fittings 36, 37
The front surfaces of the cylinders a and 37a and the surface of the cylindrical side wall 50 are very close to each other.

Regarding the rotating member 15 illustrated in FIGS. 6 and 8, when it is integrally assembled with the rotating drum 5, the damper members 19a and 19b as shown in FIG. The two magnetic heads 13a and 13b are pressed at multiple locations on the top surface.
This allows the relative heights of the parts to be adjusted and unnecessary vibrations to be suppressed in a good manner.

Also, in the rotating member 15 shown in FIGS. 6 and 8, the drive coil 22 provided on the fixed drum 2 is inserted into the DC magnetic field of the DC magnetic field generator provided therein, and the drive coil 22 is designed so that when the rotating member 15 operates as a seesaw, it and the constituent members of the DC magnetic field generating device are in a non-contact state.

9a to 9c are diagrams illustrating how the rotating member 15 is supported when the rotating member 15 is configured to perform a seesaw action, and FIG. 9a shows a bearing fixed to the rotating drum 5. This is an example in which a rotating shaft 41 supported by a rotary member 15 is inserted into the rotating member 15 to support the rotating member, and the bearing 40 is connected to the rotating drum by screws screwed into holes 40a, 40a bored in the bearing 40. 5, and FIG. 9b shows the rotating shaft 41.
is clamped by the rotating member 15 and the backing plate 42,
The cover plate 12 is configured to be connected and fixed to the center of the rotating drum 5, and further, as shown in FIG.
The figure shows a configuration in which a spring plate 43 such as a phosphor bronze plate is used as the fulcrum of the rotating member 15, and the spring plate 43 is fixed to the center of the rotating drum 5. The rotating member 15 is equipped with a support mode as shown in FIGS.
is attached to the rotating drum 5, the rotating support part of the rotating member 15 is attached to the center of the rotating drum 5, so that the rotational force is transmitted from the rotating shaft 1 to the rotating drum 5. Needless to say, the configuration for this purpose must be such that the rotational force from the rotating shaft 1 is transmitted to a portion of the rotating drum 5 that is spaced apart from the center.
It goes without saying that configurations of the rotating member 15 other than those illustrated and described may be adopted as appropriate.

The center holder 24 (damper 24) used in the rotating member 15 shown in FIG. 6 may be constructed of a spring plate such as a phosphor bronze plate.

The rotating member 15 that performs the seesaw operation described above, that is, the drive coil 22 is attached to the fixed part so as to be located in the magnetic field generated by the DC magnetic field generator provided on the rotating member 15.
When a driving current is applied to the rotating member 15, the rotating member 15 is driven and displaced so as to be tilted about a fulcrum pivoted near the perpendicular bisector of a straight line connecting the two magnetic heads. The rotating member 15 is
In both examples, the rotary drum 5 fixed to the rotary shaft 1 was configured to rotate integrally with the rotary drum 5 while also performing a tilting motion with respect to the rotary drum 5. It may also be configured such that the drum 5 rotates integrally with the rotating member 15 and the rotating drum 5 can tilt integrally with respect to the rotating shaft 1.

As an example of a configuration in which the rotating drum 5 and the rotating member 15 rotate integrally and can tilt integrally with respect to the rotating shaft 1, for example, 7. A center holder 24 as shown in FIG.
An example of such a structure is that the bottom plate of the center holder 24 is fixedly fixed to the center holder 24, and the center holder 24 is supported by the pivots 27 and 28 in the state described with reference to FIG.

In the structure exemplified above, the mass of the movable part of the magnetic head drive device is not only the mass of the rotating member 15 but also the mass of the rotating drum 5, but sufficient driving force can be obtained. Needless to say, it can be put to practical use if there are no problems in terms of the characteristics of the servo system.

As is clear from the above description, in the magnetic head drive device in the magnetic recording and reproducing apparatus of the present invention, the drive current for driving and displacing the magnetic head in the direction perpendicular to its rotation locus is applied to the rotating drum 5. The drive current is supplied to the drive coil that is provided in a stationary state on the side of the fixed part facing the member, and there is no need to supply drive current to the side of the member that is rotating. According to the magnetic head drive device of the present invention, the problems with the conventional magnetic head drive device described above can be satisfactorily solved. The heads are mounted 180° symmetrically with respect to the center position of the rotating member, and one tracking servo system can simultaneously drive and displace two magnetic heads, resulting in a tracking servo system configuration. The rotary member is simplified and is configured so that it can perform a seesaw action as a rotating member.Two magnetic heads are attached to the rotating member 180° symmetrically with respect to the center position of the rotating member, so that it can be driven easily. By passing a triangular wave current having a predetermined magnitude through the coil at a period corresponding to the rotation period of the rotating member, it is possible to make the magnetic head correctly track the recording trace during still playback and slow motion playback. In other words, by driving and displacing the magnetic head by open-loop control,
Still images and slow motion images without bar noise in the reproduced images can be easily obtained.Furthermore, in the magnetic head drive device of the present invention, the main body and yoke of the rotating member are integrally made of ferromagnetic material. If the rotating member is made of a material, there will be no accumulation of errors occurring in each component or during assembly, and a highly accurate rotating member can be easily obtained.

The magnetic head drive device of the present invention may be driven by a closed-loop tracking servo system, and in this case as well, only one tracking servo system is required, so a simple tracking system is possible. A servo system can be configured. As a closed-loop tracking control system, the one described in Japanese Patent Application No. 53-21529 can be used, and it is designed so that the two magnetic heads exhibit different azimuth angles. It can also be applied favorably to a magnetic recording/reproducing device using a so-called tilted azimuth method.

In addition, as a closed-loop servo system, the patent application
162734, Japanese Patent Application No. 162735/1984, etc. may be used.

Further, in the magnetic head drive device in the magnetic recording/reproducing apparatus of the present invention, the relative heights of the two magnetic heads are arranged between the rotating drum and the rotating member provided on the rotating drum side with a buffer member interposed. By providing an adjustment mechanism capable of adjusting the height, the static position of the rotary member in a state where the rotary member is not driven is regulated, and the relative height of the two magnetic heads can be appropriately adjusted. By adding a mechanical resistance element to the mechanical resonance system of the rotating member, unnecessary vibrations of the rotating member can be effectively suppressed.

In addition, the DC magnetic field generator provided on the rotating member is a ferromagnetic material that has a vertical cross-sectional shape that looks like it is surrounded on three sides, and a planar cross-sectional shape that is arcuate or annular. A DC magnetic field is generated in the space of the body component by a permanent magnet that constitutes a part of the magnetic component, and an annular drive coil provided at the fixed part is configured to generate a DC magnetic field. Since the rotating member is placed in the magnetic field of the DC magnetic field generator provided on the rotating member, the magnetic field generated by the mechanism for driving the rotating member does not leak into the magnetic head. The magnetic head can be driven and displaced in a direction perpendicular to its rotation locus.

As described above, the magnetic head drive device in the magnetic recording and reproducing apparatus of the present invention not only satisfactorily solves all the problems in the conventional magnetic head drive device described above, but also solves the problems of the conventional magnetic head drive device. By implementing the device of the present invention, a high-performance magnetic recording and reproducing device suitable for high-density recording and reproducing can be provided at a low cost, which can obtain the various advantages mentioned above that cannot be obtained when using a drive device. make it possible.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal side view of a head drum assembly to which a magnetic head drive device in a magnetic recording/reproducing apparatus of the present invention is applied; FIG. 2 is a plan view of a rotating member connected to a pushing member; Fig. 3 is a plan view of the drive coil, Fig. 4 is an explanatory diagram for explaining the see-saw movement of a rotating member that performs seesaw movement, and Figs. FIG. 7 is an exploded perspective view of the rotary member shown in FIG. 6, and FIGS. 9 a to 9 c are views of modified examples of the support mode of the rotary member. 1... Rotating shaft, 2... Fixed drum, 3... Bearing, 5...
Rotating drum, 6... Pushing, 7... Base plate, 9... Mounting part for fixed winding of rotating transformer, 10
... Mounting part of the rotating winding of the rotating transformer, 12a, 1
2b... Head bracket, 13a, 13b... Magnetic head, 15... Rotating member, 16a, 16b... Yoke portion, 17, 17a, 17b... Permanent magnet, 19
a, 19b... Damper member, 20a, 20b... Screw, 22, 48, 49... Drive coil, 23... Connecting portion, 24... Center retainer, 25, 26... Holding metal fitting,
27, 28...Pivot, 31...Bottom plate, 50...Cylindrical side wall.

Claims (1)

[Claims] 1. In a rotating head type magnetic recording and reproducing device in which information signals can be recorded and reproduced by relative movement between a magnetic head and a magnetic tape, A rotating member with magnetic heads installed at symmetrical positions,
The rotation support section provided near the perpendicular bisector of the straight line connecting the magnetic heads allows the plane containing each magnetic head to form a plane orthogonal to the extending direction of the rotation axis during rotation. The rotary member is rotatably supported so that its angle can be changed, and the rotary member is provided with a direct current magnetic field including permanent magnets at portions on opposite sides of the rotary support portion. One of the DC magnetic field generating devices described above generates a magnetic field in a direction from the rotation support part side of the rotating member toward the outer end side of the rotating member, and The other of the generators is capable of generating a magnetic field in the direction from the outer end of the rotating member toward the rotation support portion of the rotating member, and is further provided on the rotating member. A magnetic head drive device in a magnetic recording/reproducing device, comprising a ring-shaped drive coil placed in a magnetic field generated by a DC magnetic field generator, which is mounted on a fixed part facing the rotating member. 2. As a DC magnetic field generator installed in a rotating member, a DC magnetic field is generated in a space having a vertical cross-sectional shape surrounded on three sides by ferromagnetic constituent members. A magnetic head drive device in a magnetic recording/reproducing apparatus according to claim 1. 3. As a DC magnetic field generator provided on a rotating member, one was used that had a vertical cross-sectional shape that seemed to be surrounded on three sides, and was equipped with a yoke whose planar cross-sectional shape was arcuate or annular. A magnetic head drive device in a magnetic recording/reproducing apparatus according to claim 1. 4. The invention according to claim 1, wherein the rotating member is integrally made of ferromagnetic material, including the yoke that constitutes a part of the DC magnetic field generator. A magnetic head drive device in a magnetic recording/reproducing device. 5. A rotating member, to which a magnetic head is attached and a direct current magnetic field generator including a permanent magnet is attached, and is configured to be rotated at a predetermined speed, is driven by a rotational drive shaft. A magnetic head drive device in a magnetic recording and reproducing apparatus according to claim 1, wherein the magnetic head drive device is provided on the side of a rotary drum that is rotationally driven. 6 Rotating members each having a magnetic head attached at a 180 degree symmetrical position with respect to the center of rotation are rotated by a rotating support provided near the perpendicular bisector of the straight line connecting the magnetic heads. The rotary member is rotatably supported so that the angle between the plane containing each magnetic head and the plane orthogonal to the longitudinal direction of the rotation axis can be changed during rotation, and the rotary member has a rotation support portion thereof. Direct current magnetic field generators each including a permanent magnet are provided at opposite positions, and one of the DC magnetic field generators is mounted on the rotation support side of the rotating member. A magnetic field is generated in the direction toward the outer end of the rotating member,
The other of the DC magnetic field generators described above is capable of generating a magnetic field in a direction from the outer end of the rotating member toward the position of the rotational support portion of the information signal; An annular drive coil is provided on a fixed part opposite the rotating member to drive the head and the magnetic tape in the magnetic field generated by a DC magnetic field generator provided on the rotating member. A rotary head type magnetic recording/reproducing device that is capable of recording and reproducing information signals through relative movement, which is equipped with two magnetic heads and includes a permanent magnet. A rotating member to which a DC magnetic field generator is attached is supported on a rotating drum side that is rotationally driven by a rotational drive shaft so as to be rotationally driven substantially integrally with the rotating drum,
Further, a magnetic head is provided with an adjustment mechanism that can adjust the relative height of the two magnetic heads with a buffer member interposed between the above-mentioned rotating drum and a rotating member provided on the rotating drum side. A magnetic head drive device in a recording/reproducing device.