JPH0414601A - Rotary magnetic head device and stepup transformer used therefor - Google Patents

Abstract

PURPOSE:To prevent invasion of noise from the outside of a rotary cylinder by enclosing a major coil conductor with a magnetic material in a stepup transformer built in a rotary drum. CONSTITUTION:A stepup transformer 341 is formed by applying a troidal coil 3411 on the outer circumference of a ring core 3410. The entire surrounding of the stepup transformer 341 is enclosed by a shield member 3149 made of a ferromagnetic body except a terminal 3413 to which a coil terminal is connected. Then the stepup transformer is mounted on printed circuit boards of amplifier circuits 33, 34 and connected between a magnetic head 1 and the amplifier circuits 33, 34.

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention is applicable to VTRs (video tape recorders) and DATs.
The present invention relates to a rotating magnetic head device used in a digital audio tape recorder, etc., and a step-up transformer used therein.

FIG. 7(a) is a sectional view of a main part of a rotating cylinder of such a rotating magnetic head device, FIG. 7(b) is a plan view, and FIG. 7(C) is a perspective view.

In the figure, 1 is a magnetic head, 1' is a helad base,
2 is a rotating drum, 2' is a fixed drum, 3 is a relay plate (rotor side), 54 is a rotor core (hereinafter also simply referred to as rotor), 5 is a rotating shaft, 6 is a relay plate (stator side), 7
is a slip ring, 8 is a stator core (hereinafter sometimes simply referred to as stator), 9 is a slip ring brush,
12 is a ball bearing, and 13 is a disk. Here, the rotor core 4 and the stator core 8 constitute a rotary transformer.

As seen in the figure, the one-rotation shaft 5 is rotatably supported by the stationary drum 2'. A disk 13 is fitted and fixed to the upper part of the rotating shaft 5. A rotary drum to which the magnetic head 1 is fixed is fixed to the disk 13, and a rotor core 4 as a component of a rotary transformer is adhesively fixed to the lower end of the disk 13 coaxially with the rotating shaft.

On the other hand, the stator core 8, which is the other component of the rotary transformer, is fixed to the stationary drum 2' coaxially with the rotary shaft 5 by adhesive or the like.

A driving motor 50 is attached to the lower part of the rotating shaft 5 (lower part of the fixed drum 2') to obtain driving force (rotational force). The magnetic head 1 attached to the rotating drum 2 and the rotor 4 constituting the rotating transformer are electrically connected through pin terminals 31, 32 and the amplifier circuit board 33.
．． 34 etc.

A rotating transformer consisting of a rotor 4 and a stator 8.

Generally, the same number of coils as the number of magnetic heads 1 are arranged in grooves formed on the surface of a magnetic material core constituting the rotor or stator. The grooves are concentrically opposed to each other to transmit signals between the coils, and the rotor (magnetic core) 4 and stator (magnetic core) 8 are opposed to each other.
The distance between them is about 10 to 60 μm.

Although not shown individually, inductance elements, resistance elements, integrated circuit elements, capacitance elements, diodes, etc. are mounted on the amplifier circuit boards 33 and 34 by soldering.
341 is a step-up transformer, 342 is a recording integrated circuit element, and 343 is a reproduction integrated circuit element. In particular, the amplifier circuit board 34 has conductor patterns on both sides and the various elements described above are connected thereto.

A slip ring 7 is provided at the top of the rotating shaft for supplying power and control signals to the amplifier circuit provided in the rotating body, and a slip ring brush 9 is provided in contact with the slip ring 7. is installed. Connector 9'
Although not shown, is connected to the slip ring brush 9 and used for connection with an external circuit.

The slip ring and the amplifier circuit board 34 are connected to the lead wire 71
connected by.

Although not shown, the relay board 6 connected to the stator of the rotary transformer is connected to an external circuit via a connector 6'.

FIG. 8 shows a step-up transformer 341 which is an inductance element connected between the magnetic head and the amplifier circuit.
FIG. This is outer diameter φ4 and inner diameter φ2
■Resin base 341 with a terminal 3413 formed by applying a toroidal winding 3411 with a wire diameter of φ0.16 mm to a ring-shaped Ni-Zn ferrite core 3410 with a thickness of 1.5+ am
2 is glued and the winding end is connected to the terminal, and the coupling coefficient can be easily increased to 0.99 or more by applying bifilar winding, which distributes the coil evenly around the entire circumference of the core.
The capacitance between the primary coil and the secondary coil is approximately 5 pF, and the external dimensions are 6.9 x 6. It had a size of about OX3.8mm. In addition, the number of turns at this time is 7 in 8 turns.
μH or 21μH with 14 turns, step-up ratio of 1.5 to 2, and an intermediate tap with two coils arranged on the secondary side, the inner diameter side is approximately φ11III1
Only one space remained, making automatic winding impossible.

FIG. 10 is a block diagram showing the connection of the rotating magnetic head device shown in FIG. 7 as an electric circuit. As described above, the documents describing the conventional technology for a rotating magnetic head device with an amplifier circuit built into the rotating drum include: 1. Japanese Patent Application Laid-Open No. 57-30104 "Head Signal Switching System" 2. Japanese Patent Application Laid-Open No. 64-86301 Publication No. ``Drum device for magnetic recording/reproducing machine'' and the like can be mentioned.

[Problems to be Solved by the Invention] In the above-mentioned prior art, an erasing head is mounted in a rotating drum as shown in FIG. 10, and a toroidal winding is mounted on a ring-shaped ferrite core as shown in FIG. A rotary magnetic head device in which a step-up transformer having only the above-described characteristics is connected to an amplifier circuit and disposed within the rotary drum has the following problems.

■During recording, the erasing signal with a high signal level leaks to other channels equipped with step-up transformers, resulting in S/, which represents the ratio of the main signal of that channel to the leaked signal.
It was easy to cause interference that degraded the N ratio.

However, regardless of whether an erasing head is installed or not, in a rotating magnetic head device in which a step-up transformer consisting of a ring-shaped ferrite core and a toroidal winding is connected to an amplifier circuit and placed inside the rotating drum, the following applies. It had some problems.

(2) In a step-up transformer, the toroidal coil attached to the outer periphery of the ring-shaped magnetic material is exposed, making it easy for electromagnetic induction nozzles from outside the rotating cylinder to be guided into the coil.

■In the above step-up transformer, in order to reduce the noise caused by the leakage signal for erasure and the externally induced magnetic field, it is possible to surround the step-up transformer with a shield case made of a magnetic material, but this increases the price. , Also, it was supposed to be thicker in terms of dimensions.

■In step-up transformers, it is necessary to use bifilar winding in order to increase the coupling coefficient, so the coils must be arranged more or less uniformly around the circumference of the ring-shaped core, making it easier to wind the coils. Considering automatic winding by a machine, there were restrictions on the inner diameter of the ring core, and there was a limit to miniaturization due to size.

In order to miniaturize the step-up transformer, an electric circuit as shown in FIG. However, simply using the multilayer inductance element has the following problems.

■It is extremely difficult to make the coupling coefficient, which indicates the coupling state between the primary and secondary coils of a step-up transformer, to a value comparable to that of a conventional ring core with a bifilar-wound toroidal coil. there were. This is due to the structure of the magnetic circuit, which is also a structural flaw in the laminated inductance, and is due to the fact that the conductor coils cannot be distributed evenly over the entire area of the magnetic circuit, unlike conventional toroidal coils. .

■ Due to the necessity of miniaturization and the structural flaws of the multilayer inductance, due to spatial constraints due to the structure that makes it impossible to arrange the conductor coils evenly over the entire area of the magnetic circuit, Since the distance between the conductors of the conductor becomes extremely short, the capacitance between the conductors of the coil conductor increases, and in addition to the inductance between the terminals as an inductance element, there is a large distributed capacitance. Become. This distributed capacitance deteriorates the high frequency band characteristics of the step-up transformer's transmission characteristics.

(2) Furthermore, in order to improve the coupling coefficient, which indicates the coupling state between the primary coil and the secondary coil of a step-up transformer, it is sufficient to reduce the leakage of magnetic flux in the main magnetic circuit that constitutes the transformer.

As mentioned above, the distance between the primary coil and the secondary coil has to be reduced due to spatial constraints caused by the structure in which the conductor coils cannot be arranged evenly over the entire magnetic circuit, which is also a structural defect of the multilayer inductance. Although it is possible to reduce the leakage of the magnetic flux by bringing the coils closer together, the distance between the coil conductors becomes even shorter, which has a contradictory relationship in that the distributed capacitance between the coils increases.

An object of the present invention is to amplify a plurality of magnetic heads arranged in a multi-functional manner in a rotating drum of a rotating magnetic head device having dimensions regulated by various standards, and to amplify signals from the magnetic heads. The amplification circuit incorporates a reproduction amplification circuit to amplify the recording signal and a recording amplification circuit to amplify the recording signal, and is capable of overcoming the problems of the conventional technology and is highly productive, high-performance, compact, and low-cost. The object of the present invention is to provide a rotating magnetic head device connected between the magnetic head and the magnetic head, and such a step-up transformer itself.

[Means for Solving the Problems] In order to achieve the above object, a first rotating magnetic head device according to the present invention includes: a fixed drum having a tape guide surface; and a support rotatably inserted into the axial center of the fixed drum. A rotor core is attached to the rotary drum, a stator core is attached to the fixed drum, and the core is attached to the fixed drum with a small gap between the rotating drum and the rotary drum, which has a plurality of magnetic heads. The rotary drum has a rotary transformer that is arranged oppositely to transmit and receive signals through the rotary drum. In the rotary magnetic head device in which a step-up transformer is built in the magnetic head and is connected between the amplifier circuit and the magnetic head, a main coil conductor of the step-up transformer is surrounded by a magnetic member.

For example, in a step-up transformer of the type in which a toroidal coil is placed around the outer circumference of a ring-shaped core, almost the entire circumference is surrounded by a shielding member made of a magnetic material, except for only the terminal part where the coil terminal is connected, or the coil is not connected. We decided to cover the amplifier circuit board with a bowl-shaped shielding member made of magnetic material, except for the terminal section to which the coil terminal was connected.

Further, in the first rotary magnetic head device according to the present invention, even when the plurality of magnetic heads include at least one erasing head, in the rotary magnetic head device as described above, the main part of the step-up transformer is We decided to surround the coil conductor with a magnetic member.

Further, in a second rotary magnetic head device according to the present invention, in the rotary magnetic head device as described above, as another means for surrounding the main coil conductor of the step-up transformer with a magnetic member, a laminated type is used. A step-up transformer was constructed using an inductance element.

In the second rotary magnetic head device, the coupling coefficient between the primary coil and the secondary coil of the step-up transformer is set to be 0.970 or more.

Further, in the second rotary magnetic head device, a limit value is set for the distributed capacitance between the coil conductors of the step-up transformer, and one parameter is set for the distributed capacitance between the primary coil and the secondary coil.
The capacitance value between the secondary coils was set to 14 pF or less.

Furthermore, it was decided that both the coupling coefficient and the capacitance between the primary coil and the secondary coil of the step-up transformer satisfy the aforementioned limit values at the same time.

Furthermore, it was decided that both the coupling coefficient and the capacitance between the primary coil and the secondary coil of the step-up transformer satisfy the above-mentioned limit values at the same time, and a limit value was also set for the external dimensions.

[Function] Coils arranged in grooves provided in the plane of opposing magnetic bodies (rotor core and stator core) in a rotating transformer used in a rotating magnetic head device that does not have an electric amplification circuit built into the rotating drum. The number of turns of this coil conductor is determined to be the optimum value depending on the constants of the magnetic head and electric circuit to be connected. Magazine published monthly: [National Technical Report] Vol. 18, No. 4 (National Technical Rep)
ort, vol, 18. No, 4. August, 1972)
This is what is shown in ``Rotating Transformer'' (Iida, Kuchinaka), etc.

The rotary transformer has the same number of coils as the number of general magnetic heads, and the number of grooves formed on the surface of the magnetic material core is greater than the number of coils. As the number of magnetic heads, each with a dedicated function, increases due to multi-functionalization, the facing area per groove in the rotary transformer decreases, the coupling coefficient etc. decreases, and the transmission efficiency deteriorates. It happens. As a method to compensate for the deterioration of the transmission efficiency of this rotary transformer, an electric amplification circuit is built into the 5-rotation drum to amplify the reproduction signal generated in the magnetic head, and also to amplify the recording signal supplied to the magnetic head. This is an attempt to improve performance, and is disclosed in Japanese Patent Laid-Open Publication No. 57-30104.

Between the magnetic head and the amplification circuit, there is a connection between the magnetic head and the amplification circuit in order to match electrical constants such as impedance of the magnetic head when viewed from the amplification circuit side, or to boost the voltage generated in the magnetic head. A step-up transformer is connected, and the north step-up transformer is simply a ring-shaped ferrite core with toroidal winding, and the coil is either bare or molded with resin. Although there are some, they are generally not magnetically shielded.

Since the step-up transformer is designed to boost voltage etc., it also increases various induced noises from the outside that enter this part. Also, from the configuration of the step-up transformer.

It also uses a magnetic member, and has the property of converging the external electromagnetic induction magnetic field and the like on the magnetic member depending on the surrounding conditions.

Therefore, magnetically shielding the step-up transformer itself is an effective means for suppressing the various types of induced noise from the outside.

Furthermore, this is a particularly effective means for externally induced noise when the source thereof is inside the rotary cylinder body, for example when one groove in the rotary transformer is used for elimination.

As mentioned above, when there are a large number of magnetic heads, the transmission efficiency of the rotating transformer deteriorates. The level of magnetic field generated within the transformer also increases, and along with the deterioration of the coupling coefficient described above, the level of magnetic flux leaking from the rotating transformer also increases, which tends to cause noise that is harmful to other signals. When a plurality of magnetic heads, amplification circuits, etc. are built into a space, distance factors can also be taken into account.

Magnetically shielding the step-up transformer itself is an effective means for suppressing various types of induced noise from the outside as described above, but it is also an effective means to suppress various induced noises from the outside. Due to size constraints, the step-up transformer also needs to be miniaturized.

By configuring the step-up transformer using a laminated inductance element to meet this requirement, it is possible to obtain a small-sized step-up transformer that does not particularly require an external magnetic shielding member.

Due to its structure, a multilayer inductance element has a coil conductor inside a magnetic material, so the coil is covered with a magnetic material.When designing the magnetic circuit, it is necessary to If consideration is given to creating a cross-sectional structure in which the area of the part sandwiched between the coil conductors and inside the coil conductor is smaller than other parts, the noise caused by the externally induced electromagnetic field will be reduced due to the magnetic resistance of the magnetic circuit. Since the magnetic field mainly passes through the magnetic path outside the coil, noise is less likely to be induced into the coil, and it is possible to suppress the intrusion of noise due to externally induced magnetic fields.

However, compared to conventional types that use a ring core, multilayer inductance elements have a structural constraint that makes it impossible to arrange conductor coils evenly over the entire magnetic circuit. It has the disadvantage that the coupling coefficient, which indicates the coupling state between coils, cannot be increased.

However, by bringing the relative magnetic permeability of parts other than the conductor that do not constitute the main magnetic circuit as close to 1 as possible, and by increasing the dimensional accuracy of the laminated part of the coil conductor and magnetic layer, the border between the coil conductor and the main magnetic circuit can be improved. In addition, like the bifilar winding used in conventional toroidal coils, the primary coil and secondary coil should overlap as much as possible over the entire magnetic circuit. As a result of using means to reduce leakage magnetic flux, such as maintaining the coupling coefficient, it was possible to increase the coupling coefficient to 0.970 or more.

The coupling coefficient of the stacked step-up transformer is 0°970.
Based on the above, if bifilar winding is applied to the conventional toroidal coil type, it is relatively easy to reduce the coupling coefficient to 0.
Even when compared with those that can have a transmission characteristic of 99 or higher, the transmission characteristics can be almost the same.

However, in a stacked step-up transformer, the coupling coefficient, which indicates the coupling state between the primary coil and the secondary coil, is set to 0.
If the above-mentioned measures are simply taken to increase the value to 970 or more, it is also a structural defect in the multilayer inductance.
Coupled with the spatial constraints resulting from the structure where the coil conductors cannot be distributed evenly over the entire magnetic circuit, the distance between the coil conductors becomes physically smaller, increasing the distributed capacitance between the conductors. Therefore, in addition to the inductance between the terminals as an inductance element, there is also a large distributed capacitance, and the capacitance value between the primary coil and the secondary coil, which is one parameter representing this distributed capacitance, is 14 pF.
As a result, the transmission characteristics in a high frequency band of 5 MHz or higher will deteriorate.

Therefore, by setting the distance between the conductors of the coil conductor to an appropriate value or more, the coupling coefficient indicating the coupling state between the primary coil and the secondary coil can be set to 0.970 or more, and the distance between the primary coil and the secondary coil can be set to 0.970 or more. It is now possible to reduce the capacitance value to 14 pF or less, and the transmission characteristics can be made equivalent to those of conventional types.

In addition, by increasing the magnetic permeability of the ferrite material that makes up the magnetic circuit of the laminated inductance element, the inductance value per turn of the coil can be increased, so the external dimensions can be reduced without increasing the number of turns of the coil, and the rotating drum can be This increases the number of circuit elements that can be installed inside the drum, making it multifunctional, and also making it possible to mount an amplifier circuit inside a small-diameter rotating drum.

[Example code] The present invention will now be described in detail with reference to the drawings.

FIG. 1(a) shows a sectional view of a main part of an embodiment of a rotating cylinder of a rotating magnetic head device of the present invention, FIG. 1(b) is a plan view thereof, and FIG. 1(C) is a perspective view thereof.

In this figure, the same or corresponding parts as in FIG. 7 are given the same reference numerals.

That is, FIG. 1(a) shows that the step-up transformer 341 connected and mounted on the amplifier circuit boards 33 and 34 is of a small type in which the main coil conductor is surrounded by a magnetic member. There is.

A connection system diagram of the electric circuit is shown in FIG. 10 6, which shows the case where an erasing head is mounted as one of a plurality of magnetic heads l in the rotating drum 2.

In the figure, 1 is a magnetic head, 1' is a helad base,
2 is a rotating drum, 2' is a fixed drum, 3 is a relay plate (rotor side), 4 is a rotor core, 5 is a rotating shaft, 6 is a relay plate (stator side), 7 is a slip ring, 8 is a stator core,
9 is a slip ring brush, 12 is a ball bearing, and 13 is a disk.

Here, the rotor core 4 and the stator core 8 constitute a rotary transformer. This figure does not accurately show the grooves disposed within the core, the signal transmission coils disposed within the grooves, and the like.

The slip ring 7.9 supplies power to an amplifier circuit disposed within the rotating drum, as well as control signals for playback/recording timing and the like. Various signals transmitted to the slip ring 7 are connected to the amplifier circuit board 34 through lead wires 71.

It is electrically connected to other amplifier circuit boards 33 through pin terminals 32 and the like, and is also connected to the relay plate 3 through which the lead ends of the coils arranged on the rotor core 4 are guided.

The magnetic head 1 and the amplifier circuit board 33 are electrically connected by the pin terminals 31 .

Although detailed conductor patterns are not shown on the surface of each amplifier circuit board 33 and 34, the step-up transformer 34
1. Recording integrated circuit 342, reproducing integrated circuit 343. In addition to these, inductance elements, resistance elements, capacitance elements, diodes, etc. are soldered.

Each of the amplification circuit boards 33 and 34 is fixed to the disk 13 and the rotating drum 2 with screws or the like.

Note that the amplifier circuit board 34 has circuits configured on both sides, and if an iron board with an insulating film applied to the surface is used, it will function as a magnetic shield plate for the rotating drum.

FIG. 9 shows the arrangement of the magnetic head 1 of the rotary cylinder according to the invention on the rotary drum 2. In this figure, 10 is a magnetic tape that is wound around the outer periphery of the rotating drum 2 and is in contact with the magnetic head 1. 6 The symbols (, +) and (-) in the figure indicate the azimuth angle of the operating gap of the magnetic head, and PM is for playback monitor, REC is for recording, PB is for playback, HiFi
indicates a function for audio, FE indicates a function for erasing, etc.

The reproduction monitor mmPM head works simultaneously with the recording REC head to reproduce signals recorded on the magnetic tape without rewinding the tape, and instantly checks the operation of the RFC head. The PB' head is also used for special playback in which, in combination with other PB heads, playback is performed at a tape feed speed different from the tape feed speed during recording. The HiFi head functions for recording/reproducing audio signals. The RFC/PB head functions for recording/reproducing video signals.

The FE head functions for erasing video and audio signals.

FIG. 2 shows a transparent perspective view of an embodiment of the step-up transformer of the present invention, and (a) shows a type in which a toroidal coil 3411 is provided around the outer periphery of a ring-shaped core 3410, in which the coil terminal is connected. A shield member 3419 made of a magnetic material surrounds the entire circumference except for the terminal portion 3413, and (b) shows a case in which the shield member 3419 does not surround the entire circumference and the lid is covered with the shield member on the bowl. FIG. 3 shows a perspective view of the external appearance of an embodiment of a step-up transformer 341 based on a multilayer inductance element according to the present invention, and the symbols of the terminals in the figure indicate the second embodiment.
The same reference numerals are given to correspond to those in FIG. Symbols 1 to 2 in FIGS. 2 and 3 correspond to 1 to 2 in the circuit symbol diagrams.

FIG. 4 shows a sectional view of essential parts of a step-up transformer based on the multilayer inductance element of the present invention shown in FIG. (b) shows an example in which the secondary coil conductors are arranged evenly between the secondary coil conductors. The symbol (a) in the figure corresponds to ■ to ■ in the circuit symbol diagram, the symbol (b) similarly corresponds to ■ to ■, and the symbol (C) corresponds to ■ to ■.

In this figure, in the cross section in the direction in which voltage is induced in the coil according to the law of electromagnetism due to the induced magnetic flux penetrating from the outside, in other words, in the cross section perpendicular to the lamination direction of the coil conductor, the magnetic flux constituting the main magnetic circuit is Regarding the member portion, the area of the portion inside the coil conductor is smaller than the area of the portion outside the coil conductor.

FIG. 5 shows a model diagram of the manufacturing process of a laminated inductance element (one-turn lamination process only).

This figure shows the concept of forming a laminated coil, and details of the manufacturing method are shown in Japanese Patent Application Laid-Open No. 64-47010 and Japanese Patent Application Laid-open No. 1-198003.

The cross-sectional configuration is as shown in Figure 4 above, the magnetic ferrite material is made of Ni-Cu-Zn material with a relative magnetic permeability of about 200, and the conductor is made of Ag-Pd material. The distance between the conductors is approximately 50 μm, and the distance between the conductors is set to be 50 μm or more due to the relationship between the capacitance between the coils. Fifth
Although not shown in the figure, by placing a member close to a non-magnetic material with a relative magnetic permeability of about 1 between the coils, the distance between the primary coil (a) and the secondary coils (b) and (c) The coupling coefficient indicating the coupling state should be 0.970 or more, and the primary coil (
The capacitance value between a) and the secondary coils (b) and (c) is 14
The outer dimensions of a multilayer inductance element that can have characteristics of pF or less are approximately 5 x 5 x 2.5 mm. The number of turns of the primary coil at this time is 6 turns and 8μ
H, step-up ratio is 2, or number of turns of primary coil is 1
At 0 turn, it is 22 μH, the step-up ratio is about 1.5, and both have a symbiotic tap.

Note that in FIG. 4, conductors for coil terminals and leads for electrical connection between coils are omitted. If the relative magnetic permeability of the magnetic ferrite material is further increased, the inductance per turn can be increased, and the element can be further miniaturized.

FIGS. 6(a) and 6(b) show the transmission characteristics of the step-up transformer using the multilayer inductance element according to the present invention.
A comparison with the conventional toroidal coil type is shown. The symbol L1 in the figure represents the primary inductance, and the symbol L1 represents the primary coil and the secondary inductance.
Cs represents the coupling coefficient between the secondary coils, and the capacitance value between the primary coil and the secondary coil.

In the same figure (a), it can be seen that if Cs is at the same level, the transmission level is proportional to the value of K, and that the transmission level is improved when Cs is 14 pF or less.

In the same figure (b), an example is shown in which Cs is further reduced to about 12 μH, and even if Cs is 14 pF or less, K is o.
, 97 or less, it can be seen that the characteristics in the high frequency band are degraded.

FIG. 6(c) shows the amount of leakage of the cancellation signal to the main signal in a certain channel when the step-up transformer according to the present invention is used. Figure 6 (
d) shows the induced noise level at the output of the channel when a rotating cylinder is left in a strong electric field. It can be seen from both figures that there is a noise suppression effect.

[Effects of the Invention] According to the present invention, the following effects can be expected.

(1) Due to the function of the step-up transformer, the electromagnetic induction noise from outside the rotating cylinder will also amplify the noise that enters this part, so the outer periphery of the step-up transformer should be magnetically shielded. As a result, it has a strong suppressing power against the intrusion of noise.

(2) Especially when the erasing head is mounted inside the rotating drum,
Since the erasing circuit and other signal circuits to which the step-up transformer is connected are close to each other, by magnetically shielding the outer periphery of the step-up transformer, in addition to the above effects, it is possible to prevent the erasing signal from entering. It has strong suppressive power.

(3) By configuring the step-up transformer using a laminated inductance element, there is no need to magnetically shield the outer periphery of the step-up transformer with a separate member.

(4) By configuring a step-up transformer using a laminated inductance element, coil formation can be performed using printing technology, making it possible to significantly reduce the number of man-hours. Furthermore, in conjunction with item (3), it is possible to achieve miniaturization.

(5) The coupling coefficient indicating the coupling state between the primary coil ζ secondary coil in the performance of the step-up transformer is 0.97.
By setting the capacitance value to 0 or more and setting the capacitance value between the primary coil and the secondary coil to 14 pF or less, the transmission characteristics can be made to have no practical problems.

(6) If the magnetic circuit is made of a material with even higher relative magnetic permeability, the step-up transformer can be made smaller than above, which increases the number of electric circuit elements arranged in the rotating drum, and increases the Functionality can be achieved.

Additionally, it becomes possible to mount an amplifier circuit on a small diameter drum, which was previously considered impossible. .

For example, the outer diameter of the rotating drum according to the VH5 standard is φ62mm.
Therefore, if the configuration shown in Figures 1 and 10 is used in the rotating drum, an amplifier circuit can be installed as in this example, but VH5
-C standard requires simply doubling the number of heads in order to have the same functionality as the VH3 standard, so the outer diameter is φ4
It can be inferred that this cannot be achieved with a 1.3 mm rotating drum simply by reducing its functionality. Even if elements other than the step-up transformer are integrated and miniaturized using current semiconductor technology, it is impossible to mount an amplifier circuit on the step-up transformer of the conventional size described above. However, as mentioned above, if the magnetic circuit is made of a material with higher relative magnetic permeability, a step-up transformer is used. It becomes possible to reduce the size to less than b x 3.5 x 3.5 mm, and it becomes possible to mount one additional circuit, which was previously impossible.

[Brief explanation of the drawing]

FIG. 1(a) shows the rotation of the present invention! 1 is a cross-sectional view of a main part of an embodiment of a rotating cylinder of a gas head device. FIG. 1(b) is a plan view thereof, and FIG. 1(c) is a perspective view thereof. FIG. 2 shows a transparent perspective view of an embodiment of the step-up transformer of the present invention, and (a) shows a terminal portion to which a coil end is connected to a type in which a toroidal coil is provided around the outer periphery of a ring-shaped core. The shield member made of magnetic material surrounds the entire circumference except for (b). An example is shown below. FIG. 3 is a perspective view showing the appearance of an embodiment of a step-up transformer based on the multilayer inductance element of the present invention. FIG. 4 shows a cross-sectional view of the essential parts of a step-up transformer based on the multilayer inductance element of the present invention shown in FIG. (b) shows an example in which the secondary coil conductors are arranged evenly between the secondary coil conductors. FIG. 5 shows a model diagram of the manufacturing process of a laminated inductance element (one-turn lamination process only). Figures 6(,) and (b) show the transmission characteristics of the step-up transformer using the multilayer inductance element according to the present invention.
FIG. 6(C) is a diagram showing a comparison with a conventional toroidal coil type, and FIG. FIG. 6(d) is a diagram showing the induced noise level at the output of a channel when a rotating cylinder is left in a strong electric field. FIG. 7(a) shows a sectional view of a main part of an embodiment of a rotating cylinder using a toroidal coil type step-up transformer, which is a conventional rotating magnetic head device, and FIG. 7(b) is a plan view thereof. FIG. 7(c) is a perspective view thereof. FIG. 8 is an external perspective view showing the form of a conventional step-up transformer that is a toroidal coil type. FIG. 9 is a sectional view of a main part of a rotating drum showing the arrangement of magnetic heads of a rotating magnetic head device according to the present invention. FIG. 10 is a block diagram showing the electrical connections of the rotating magnetic head device according to the present invention. 1... Magnetic head, 1'... Head base, 2... Rotating drum, 2'... Fixed drum,
3... Relay plate (rotor side), 4... Rotor core, 5... Rotating shaft, 6... Relay plate (stator side), 50...・Drive motor, 6'...
... Relay plug 7 ... Slip ring, 8.
... Stator core, 71 ... Relay lead wire, 9 ... Slip ring brush, 10 ...
Magnetic tape, 9'... Relay plug for slip ring, 12.
... Ball bearing, 13 ... Disk, 31.
32...Relay pin terminal, 33.34...
・Amplification circuit board, 341...Step-up transformer, 342・
... Recording integrated circuit, 343 ... Playback integrated circuit, 3410 ... Ring core, 3411 ...
・Coil, 3412...Resin base material for terminal, 34
13...Terminal 3419...Shield case, 3410'...Magnetic member for magnetic circuit, 3
414...Nonmagnetic layer. 3411'・・・Conductor for coil. (Z) 12 Tamakushi + e Uke Jl, J2 -ym7f'l hin canro J (^) (b) No. shi) Ding [Picture Z] 謬(C) 6th area(d) 謬斥)

Claims (1)

[Claims] 1. A fixed drum having a tape guide surface, and a plurality of magnetic heads attached via an attachment member to a rotating shaft rotatably inserted and supported in the axial center of the fixed drum. a rotating drum, and a rotor core is attached to the rotating drum,
A stator core is attached to the fixed drum, and a rotary transformer is provided to exchange signals by placing the cores facing each other with a slight gap therebetween, and a regenerative amplification device is connected to the rotary transformer and amplifies the signal from the magnetic head. circuit, and a recording amplification circuit for amplifying a recording signal are built into a rotating drum, and a step-up transformer is connected between the amplification circuit and the magnetic head. A rotating magnetic head device characterized in that a coil conductor is surrounded by a magnetic member. 2. A fixed drum having a tape guide surface; a rotating drum having a plurality of magnetic heads attached via an attachment member to a rotating shaft rotatably inserted and supported in the axial center of the fixed drum; Attach the rotor core to the rotating drum,
A stator core is attached to the fixed drum, and a rotary transformer is provided to exchange signals by placing the cores facing each other with a slight gap therebetween, and a regenerative amplification device is connected to the rotary transformer and amplifies the signal from the magnetic head. A rotating magnetic head device in which a recording amplification circuit for amplifying a recording signal is built into a rotating drum, and a step-up transformer is connected between the amplification circuit and the magnetic head, the rotary magnetic head device including at least an erasing head. Further, a rotating magnetic head device characterized in that a main coil conductor of the step-up transformer is surrounded by a magnetic member. 3. A fixed drum having a tape guide surface; a rotating drum having a plurality of magnetic heads attached via an attachment member to a rotating shaft rotatably inserted and supported in the axial center of the fixed drum; Attach the rotor core to the rotating drum,
A stator core is attached to the fixed drum, and a rotary transformer is provided to exchange signals by placing the cores facing each other with a slight gap therebetween, and a regenerative amplification device is connected to the rotary transformer and amplifies the signal from the magnetic head. circuit, and a recording amplification circuit for amplifying a recording signal are built into a rotating drum, and a step-up transformer is connected between the amplification circuit and the magnetic head. A rotating magnetic head device characterized in that it uses a multilayer inductance element in which a coil conductor is embedded within a magnetic member. 4. The rotary magnetic head device according to claim 3, wherein the step-up transformer constituted by the laminated inductance element has a coupling coefficient between the primary coil and the secondary coil of 0.970 or more. . 5. The rotary magnetic head device according to claim 3, wherein the step-up transformer constituted by a laminated inductance element has an electrostatic capacitance between the primary coil and the secondary coil of 14 pF or less. 6. The coupling coefficient between the primary coil and the secondary coil of a step-up transformer composed of a multilayer inductance element is 0.970 or more, and the capacitance between the primary coil and the secondary coil is 0.970 or more. 4. The rotary magnetic head device according to claim 3, wherein the pF is 14 pF or less. 7. The coupling coefficient between the primary coil and the secondary coil divided by the intermediate tap of a step-up transformer that has an intermediate tap between the secondary coils and is composed of a multilayer inductance element is , 0.970 or more. 8. A step-up transformer that has an intermediate tap between the secondary coils and is composed of a multilayer inductance element, is divided by the primary coil and the intermediate tap.
4. The rotary magnetic head device according to claim 3, wherein the electrostatic capacitance with the next coil is 14 pF or less. 9. A step-up transformer that has an intermediate tap between the secondary coils and is composed of a multilayer inductance element, is divided by the primary coil and the intermediate tap.
The coupling coefficient between the primary coil and the secondary coil is 0.970 or more, and the capacitance between the primary coil and the secondary coil divided by the intermediate tap is 14 pF or less. A rotating magnetic head device according to claim 3. 10. The external dimensions of the step-up transformer composed of a multilayer inductance element are 5 mm x 5 mm x 2.
10. The rotary magnetic head device according to claim 4, wherein the diameter is 5 mm or less. 11. A step-up device characterized in that the main coil conductor is composed of a laminated inductance element embedded in a magnetic member, and the coupling coefficient between the primary coil and the secondary coil is 0.970 or more. Trance. 12. A step-up transformer characterized in that the main coil conductor is composed of a multilayer inductance element embedded in a magnetic member, and the capacitance between the primary coil and the secondary coil is 14 pF or less. . 13. The main coil conductor is composed of a multilayer inductance element embedded in a magnetic member, and the coupling coefficient between the primary coil and the secondary coil is 0.970 or more, and the primary coil and the secondary coil are The capacitance between the next coil is 14pF
A step-up transformer characterized by: 14. The main coil conductor is embedded within the magnetic member, 2.
It is composed of a multilayer inductance element having an intermediate tap between the secondary coils, and the coupling coefficient between the primary coil and the secondary coil divided by the intermediate tap is 0.
．． A step-up transformer characterized by 970 or higher. 15. The main coil conductor is embedded within the magnetic member, 2.
The capacitance between the primary coil and the secondary coil divided by the intermediate tap is 1.
A step-up transformer characterized by a voltage of 4 pF or less. 16. The main coil conductor is buried within the magnetic member, 2
It is composed of a laminated inductance element having an intermediate tap between secondary coils, and the coupling coefficient between the primary coil and the secondary coil divided by the intermediate tap is 0.
970 or more, and the capacitance between the primary coil and the secondary coil divided by the intermediate tap is 14 pF.
A step-up transformer characterized by: 17. The external dimensions of the multilayer inductance element in which the main coil conductor is embedded in the magnetic member are 5 mm x 5 mm x
17. The step-up transformer according to claim 11, wherein the step-up transformer has a diameter of 2.5 mm or less.