JP2972249B2 - Rotary magnetic head device and rotary transformer used for it - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary magnetic head device used for a VTR (video tape recorder), a DAT (digital audio tape recorder), and the like, and a rotary transformer used therefor. is there.

[Conventional technology]

FIG. 7 is a sectional view of a main part of a rotary cylinder of the rotary magnetic head device. In the figure, 1 is a magnetic head,
1 'is a head base, 2 is a rotating drum, 2' is a fixed drum, 3 is a relay plate (rotor side), 4 is a rotor core (hereinafter sometimes simply referred to as a rotor), 5 is a rotating shaft, 6
Is a relay plate (stator side), 7 is a coil (rotor side), 8 is a stator core (hereinafter sometimes simply referred to as a stator), 9 is a coil (stator side), 12 is a ball bearing, and 13 is a disk. is there. Here, the rotor transformer is constituted by the rotor core 4 and the stator core 8.

As can be seen in the figure, the rotating shaft 5 is fixed drum 2 '.
It is supported rotatably. A disk 13 is fitted and fixed to the upper part of the rotating shaft 5. A rotating drum on which a magnetic head is fixed is fixed to the disk 13.
At the lower end of 13, a rotor core 4 as a component of the rotary transformer is adhesively fixed coaxially with the rotary shaft.

On the other hand, the stator core 8 as the other component of the rotary transformer is fixed to the fixed drum 2 ′ by adhesion or the like coaxially with the rotary shaft 5.

Although not shown below the rotary shaft 5 (below the fixed drum 2 '), a drive motor is attached to obtain a driving force (rotational force). The electrical connection between the magnetic head 1 attached to the rotating drum and the rotor 4 constituting the rotary transformer is made by a male relay 31 and a female relay.
This is done by contact with 32.

The rotary transformer composed of the rotor 4 and the 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 a rotor or a stator, and are provided on a magnetic core as a rotor 4 and a magnetic core as a stator 8, respectively. The conveyed grooves are concentrically opposed to each other to transmit a signal between the coils. The distance between the opposed rotor (magnetic core) 4 and stator (magnetic core) 8 is about 10 to 60 μm. Has become.

FIG. 8 shows a cross section of a main part when the rotor core 4 and the stator core 8 constituting the rotary transformer face each other. FIGS. 8A and 8B show an insulating coating on the outer periphery like a polyurethane copper wire. An example in which the applied conductor is molded into a circular shape and fixed to the groove 41 or 81 with the adhesive 11 as 7, 9
(C) and (d) show examples in which spiral coils 7, 9 are simultaneously formed directly in a plurality of grooves on a core surface by plating, etching, or the like utilizing sputtering, vapor deposition, and photolithography technology. (B) and (c) show examples of coils having a unit number of turns.

In order to connect the winding start portion and the winding end portion of the coils 7 and 9 to the relay, etc., coil ends which are not directly involved in signal transmission between the rotor 4 as a rotary transformer and the stator 8 are used. It is necessary to lead the lead portion of the magnetic core 4 or 8 to the surface of the magnetic core 4 or 8 on the side opposite to the facing surface. FIG. 9 is a perspective view showing a conventional form of such a lead portion.

FIG. 9 (a) shows the leading end 7 of the coil 7 on the surface on the opposite side using the through hole 401 provided in the groove 41 of the magnetic core 4 for the coil 7 having a plurality of turns in FIG. 8 (a). And the end lead portion 7 "is drawn out. In the same one hole 401, the start end lead portion 7 'and the end lead portion 7" are drawn.
It will be appreciated that the following has also been inserted.

FIG. 9 (b) shows the coil 7 having the unit number of turns shown in FIG. 8 (b).
The through holes 401a and 401b are independently formed at the ends of the grooves 41 and the like.
And the leading end 7 'of the coil 7 is provided with a through hole 40.
FIG. 1A shows an example in which the terminal lead portions 7 ″ are respectively inserted into the through holes 401b.

FIG. 9 (c) shows the rotor core 4 shown in FIG. 8 (c).
In the coil 7 having the unit number of turns as shown in the above, two through holes 401a and 401b are provided in the groove 41, and the leading end lead portion 7 'is
FIG. 01a shows an example in which the end lead portions 7 ″ are respectively inserted into the through holes 401b.

FIG. 9 (d) shows that the draw-out grooves 410 are formed in the coil grooves 41 of the magnetic core 4 instead of using the plurality of turn coils of FIG. 8 (a) by providing through holes. Using this, the start lead 7 'and the end lead 7 "
An example is shown in which the key is extracted.

FIG. 9 (e) shows a spiral coil 7 formed simultaneously in a plurality of grooves by plating, etching or the like using sputtering, vapor deposition and photolithography techniques as shown in FIG. 8 (d). In two through holes 401a and 401b provided near 41, the leading end lead portion 7 'is in the through hole 401a,
An example is shown in which the lead portion is formed simultaneously with the formation of the coil 7 so that the terminal lead portion 7 ″ is separately drawn out into the through hole 401b.

FIGS. 10 (a), (b) and (c) are views showing a conventional example of a rotor core of a rotor core and a stator core constituting a rotary transformer, wherein (a) is a plan view and (b) is a plan view. Sectional view, (c) is a back view. In these figures, 4 is a core, 40 is a positioning groove, 42 is a groove for a short ring, 41, 4
3,44,45 are coil grooves, and 401 to 405 are through holes. Each of the through holes 401 to 405 penetrates from one side of the core 4 to the other side, and the lead portion at the beginning or end of the coil provided in the coil grooves 41, 43, 44, 45 passes through the through hole. It is needless to say that the required electrical connection is made by being guided to the other side of the core 4.

FIGS. 10 (d), (e) and (f) are diagrams showing a conventional example of a stator core of a rotor core and a stator core constituting a rotary transformer, where (d) is a plan view and (e) is a plan view. Sectional drawing, (f) is a back view. In these figures,
8 is a core, 80 is a positioning groove, 82 is a groove for a short ring,
81, 83, 84 and 85 are coil grooves, and 801 to 805 are through holes.
The stator core has almost the same structure and operation as the rotor core.

11 (a), (b) and (c) show another conventional example of a rotor core, where (a) is a plan view, (b) is a sectional view,
(C) is a back view. Here, two sets of through-holes 401 to 405 are provided with subscripts “a” and “b”, respectively, and the start and end leads of the coil are guided to the other side of the core 4 through separate holes. An example is shown in which the required electrical connections are made.

11 (d), (e) and (f) are views showing another conventional example of a stator core, where (d) is a plan view, (e) is a cross-sectional view, and (f) is a rear view. . Two sets of through holes 801 to 805 are provided with subscripts a and b, respectively.

12 (a), (b) and (c) are views showing another conventional example of the rotor core, where (a) is a plan view, (b) is a cross-sectional view, and (c) is a rear view. . Here, two sets of through-holes 401 to 405 are provided with subscripts “a” and “b”, respectively, and the start and end leads of the coil are guided to the other side of the core 4 through separate holes. An example is shown in which the required electrical connections are made.

12 (d), (e) and (f) are views showing another conventional example of a stator core, where (d) is a plan view, (e) is a sectional view, and (f) is a back view. . Two sets of through holes 801 to 805 are provided with subscripts a and b, respectively.

13 (a), 13 (b) and 13 (c) are views showing still another conventional example of a rotor core, where (a) is a plan view, (b) is a sectional view, and (c) is a back view. is there. Where 41-45,410-45
0 is each groove.

13 (d), (e) and (f) show still another conventional example of a stator core, where (d) is a plan view, (e) is a sectional view, and (f) is a back view. is there. 81 to 85 and 810 to 850 are grooves, respectively.

14 (a), (b) and (c) show still another conventional example of a rotor core, where (a) is a plan view and (b)
Is a sectional view, and (c) is a back view. Where 401a, 401b
Is a single through-hole, but non-magnetic inclusions 10
Is divided into two small holes.

14 (d), (e), and (f) show still another conventional example of a stator core, where (d) is a plan view,
(E) is a sectional view, and (f) is a back view. 801a, 801b
Is a single through-hole, but non-magnetic inclusions 10
Is divided into two small holes.

The conventional rotary magnetic head device and the rotary transformer used therein have been described above. Japanese Patent Application Laid-Open No. Sho 59-78508 describes such a conventional technology.
JP-A-61-201405, JP-A-62-179107, JP-A-62-114868, JP-A-57-29295, JP-A-63-11686, JP-A-63-114686 80510 publication and the like.

[Problems to be solved by the invention]

In the above prior art, for example, FIG.
As described with reference to (c), (e), etc., in the rotary transformer of the type in which the start and end leads of the coil are guided from one side of the core to the other side through separate holes, respectively, the rotor of the rotary transformer is used. There has been a problem that the coupling coefficient between the core side coil and the stator core side coil is deteriorated, and the signal transmission efficiency between the two coils is reduced.

In other words, if the start lead and the end lead are guided from one side of the core to the other through the same hole, the direction of the current flowing through the start end and the direction of the current flowing through the end lead are naturally opposite directions. However, since the magnetic field components generated in both leads cancel each other and become close to zero, the coupling coefficient between the coil on the core side and the coil on the stator core side is not adversely affected. In the case of guiding through individual holes, such cancellation cannot be expected. Therefore, a magnetic field component generated from each lead exerts an adverse effect, and the coupling coefficient deteriorates.

In particular, in a rotary transformer in a rotary magnetic head device equipped with a large number of magnetic heads, a combination of a coil on the rotor core side and a coil on the stator core side is provided by the number of the magnetic heads. In some cases, the coupling coefficient was significantly deteriorated as described above.

As described with reference to FIG. 16, in a rotary transformer in which the same hole is partitioned into two small holes with a non-magnetic substance and the start and end leads are passed through each of the small holes, the deterioration of the coupling coefficient is reduced. It could be improved, but required a non-magnetic material to place the holes in order to partition.

It is very difficult to arrange such a non-magnetic substance and partition the same hole of the magnetic core into two minute small holes with high dimensional accuracy, and even at the contact portion between the magnetic core and the non-magnetic substance, It is very difficult to form the structure without any gaps, and the man-hours required for the production are enormous.

Also, as another example, an insulator is arranged between coil conductors as disclosed in JP-A-63-80510 as another example in which the leading and trailing leads of a coil formed by photolithography are guided into the same hole of a magnetic core. The method of connecting to the lead conductor of another member and disposing the lead conductor in the through-hole requires a step of applying an insulating material and connecting the lead conductor to the through-hole. Thus, electrical connection with other members is required.

An object of the present invention is to overcome such a problem in the prior art, without deteriorating the coupling coefficient between the coil on the rotor core side and the coil on the stator core side, and using a through hole provided in the core constituting the rotary transformer. A rotary magnetic head device formed by using a rotary transformer, which is high in productivity and high in performance without adding extra man-hours to the formation, and in particular, there is no need to arrange an insulating member between conductors, and such a rotary magnetic head device. It is to provide a rotary transformer itself.

[Means for solving the problem]

In order to achieve the above object, in the first rotary magnetic head device according to the present invention, among the rotor core and the stator core constituting the rotary transformer, the rotor core is mounted on the rotary drum, and the stator core is mounted on the fixed drum. A recording signal is supplied to the magnetic head on the rotary drum side from the side via the rotary transformer, and a reproduction signal from the magnetic head is transmitted to the fixed drum side via the rotary transformer. In one or both of the rotor core and the stator core constituting the rotary transformer, a pair of through holes are provided in a thickness direction in a soft ferrite body which is a magnetic material constituting the core, and the pair of through holes are connected to each other. Assuming that the width of the connecting portion to be connected is smaller than the diameter of the through hole, the connecting portion magnetically adjusts the width. It is like a single through hole, and the start and end of a conductor as a coil applied to the surface of the magnetic material constituting the core are guided to the back surface of the magnetic material through the connected through holes. Connection.

Further, in the second rotating magnetic head device according to the present invention,
In the rotating magnetic head device as described above, at least one of the rotor core and the stator core constituting the rotating transformer, the conductor provided on the surface of the core is formed by at least photolithography technology,
When the starting and ending ends of the conductor as a coil and the conductor as a lead also provided on the back surface and the required connection is made through a through-hole, the depth of the groove for disposing the conductor is specified as 0.05 to 0.15 mm. I do. In other words, if the depth of the groove is 0.05 to 0.15 mm, a small amount of coating becomes possible by screen printing or the like in applying the adhesive for bonding the conductor to the inside of the groove, and even if the conductor is pressed, it will protrude outside the groove And the thickness of the adhesive layer is 0.01
It can be controlled on the order of mm.

In the first and second rotary magnetic head devices, one or both of the rotor core and the stator core constituting the rotary transformer are provided in a thickness direction in a soft ferrite body which is a magnetic material constituting the core. The cross-sectional shape of the through-hole provided in (1) has a square shape, or at least one side of the cross-section has a straight line.

Further, in the first and second rotary magnetic head devices, in one or both of the rotor core and the stator core constituting the rotary transformer, a soft ferrite body which is a magnetic material constituting the core is formed in a thickness direction thereof. The position where the through hole is provided is a portion where the spiral conductor is not disposed on the opposing surface of the core, a bank portion which constitutes both sides of the groove where the conductor is disposed, and an annular shape which constitutes a main magnetic circuit. It is arranged in a groove provided so as to cut off the ring in the facing portion.

Further, in the first rotary transformer according to the present invention, in one or both of the rotor core and the stator core constituting the rotary transformer, a soft ferrite body which is a magnetic material constituting the core is provided in a thickness direction thereof. Providing a pair of through holes, as the width of the connecting portion connecting the pair of through holes is smaller than the diameter of the through hole,
The connecting portion magnetically acts as a single through-hole, and the starting and ending ends of a conductor as a coil formed on the surface of the magnetic material constituting the core are passed through the connected through-holes to form the magnetic material. We decided to make the necessary connections by guiding to the back of the body.

Further, in the second rotary transformer according to the present invention, in one or both of the rotor core and the stator core constituting the rotary transformer, a starting end of a conductor as a coil provided on a surface of a magnetic material constituting the core When a necessary connection is made through a through hole with a conductor as a lead also provided on the back surface, the depth of the groove in which the conductor is arranged is specified as 0.05 to 0.15 mm.

In the first and second rotary transformers, in one or both of the rotor core and the stator core constituting the rotary transformer, a soft ferrite body which is a magnetic material constituting the core is provided in a thickness direction thereof. The cross-sectional shape of the through hole to be formed has a square shape, or at least one side of the cross-section has a straight line.

In the first and second rotary transformers, one or both of the rotor core and the stator core forming the rotary transformer penetrates through a soft ferrite body which is a magnetic material forming the core in a thickness direction thereof. The position where the hole is provided is a portion where the spiral conductor is not disposed on the opposing surface of the core, a bank portion which constitutes both sides of the groove where the conductor is disposed, and an annular opposed portion which constitutes a main magnetic circuit. The ring is arranged in a groove provided so as to cut off the ring.

[Action]

In the rotary transformer, signals are transmitted and received between coil conductors arranged in grooves provided in the plane of the magnetic material (rotor core and stator core) facing each other, and the number of turns of the coil conductor is The optimum value is determined according to the constants of the magnetic head and the electric circuit to be connected. A magazine published by Matsushita Electric Industrial Co., Ltd., August 1972: "National Technical Report" Vol. 18 No. 4 (National Technical Report)
t, vol. 18, No. 4, Aug. 1972) "Rotating transformer" (Sakata, Tanaka).

The quality of the rotary transformer is represented by a coupling coefficient K between the rotor coil and the stator coil. This coupling coefficient is represented by the following equation (1), where is a leakage inductance, and L is a combination inductance.

In particular, reducing the leakage inductance increases the coupling coefficient, which leads to an improvement in signal transmission efficiency.

The presence of a magnetic material having a high magnetic permeability in the conductor path contributes to the L component where the inductance component floats, but the lead portions corresponding to the winding start portion and the winding end portion of the conductor for the coil are formed by a core. A portion corresponding to the path of the through-hole provided in the magnetic material acts as a leakage inductance as an ineffective component.

Therefore, when each lead portion conductor for the start end portion and the end portion is guided through each independent through hole provided in the magnetic body, the leakage inductance increases in proportion to the length of the through hole. It will be.

Even though the two through-holes made of a magnetic material are connected to each other by a slit-shaped hole, and the cross-sectional shape is substantially a gourd shape, it becomes magnetically like a single through-hole, and the winding end of the coil conductor ends. By making each lead part corresponding to the end part and the start end guided through the same through hole, the direction of each current of both lead parts is reversed, so that the inductance component is canceled. In addition, the effect of the lead portion length on the leakage inductance by the thickness of the magnetic body (corresponding to the length of the through hole) can be greatly reduced.

A spiral conductor provided on the opposite surface side of the rotor core and the stator core for transmitting a signal; and a surface opposite to the opposite surface which is electrically connected to the winding start and end portions of the spiral conductor. Specifying a core groove depth of 0.05 mm or more and 0.15 mm or less for the core groove on which the lead conductor provided on the side is arranged means that, in applying the adhesive for bonding the conductor into the groove, a small amount of coating is performed by screen printing or the like. This makes it possible to control the thickness of the adhesive layer in the order of 0.01 mm without creeping out of the groove even when the conductor is pressed.

In other words, when the groove has irregularities with a depth of 0.15 mm or more, it is impossible to precisely apply the adhesive into the groove by screen printing or the like.

Increasing the thickness of the conductor also reduces the DC resistance, which is effective in reducing transmission loss in the low frequency band of 1 MHz or less. According to etc., the thickness is 0.03 mm
From the relationship between the conductor thickness and the adhesive layer, the minimum groove depth at which the conductor disposed in the groove is not exposed from the core surface is 0.05 mm.

Furthermore, generally, increasing the occupation ratio of the conductor coil to the groove by making the groove shallower improves the performance in terms of the coupling coefficient and the like.Specifying the upper limit of the groove depth also defines the characteristic deterioration. Become.

Further, the fact that the conductor is not exposed from the core surface means that gap management between the opposed cores can be performed with high accuracy, and when each core is fixed to a fixed drum, a rotating drum, or the like, contact between the conductor and the drum causes a problem. , Short circuit failure and the like are prevented.

From the above, the depth of the core groove should be 0.15 mm for 0.05 mm or more.
By specifying the following, it is possible to obtain a high-performance rotary transformer with high reliability, high productivity, and high performance.

Next, in a groove provided on the opposed surface of the rotor core and the stator core, of the spiral conductor disposed, the through-hole for leading the winding start and end portions to the surface opposite to the opposed surface. Each cross-sectional shape has a rectangular shape, or at least one side of the cross-section has a straight line, which means that the through-hole of the conductor bonded in the groove provided on each of both surfaces of the core surface has When the conductor foil corresponding to the portion to be guided is bent into the through hole and connected in the through hole, since the edge exposed on the core surface of the through hole has a straight line, the conductor foil is bent at the edge. And the bending becomes easy, and the bending accuracy is improved.

Also, regarding the position where the through hole is provided, by providing the spiral conductor outside the annular portion where the spiral conductor is arranged, it is possible to increase the conductor width of the spiral conductor, so for a multi-channel type in which a plurality of coils are arranged, Particularly, DC resistance, which is a problem on the rotor side, can be suppressed low, which is effective for reducing the transmission loss in the low frequency band of 1 MHz or less.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a main part of one embodiment of the present invention. In this figure, the same or corresponding parts as those in FIG. 11 (a) are denoted by the same reference numerals.

That is, in FIG. 1 (a), reference numeral 41 denotes a groove for arranging a coil conductor formed on a rotor core made of a magnetic material, and reference numeral 401 denotes a start end lead and an end lead of the coil conductor from one side of the core. A through hole 20 for guiding to the other side is a slit-like connecting hole having a width smaller than the outer diameter of the through hole and connecting the through holes.

These slit-shaped holes 20 are magnetically connected, and are separated into independent through holes 401a and 401b in terms of mechanical function. The start and end leads of the coil conductor are individually passed through the two small holes 401a and 401b. The state is the first
It is shown in FIG.

In FIG. 1 (b), reference numeral 7 denotes a coil conductor arranged in a groove 41, 7 'is a leading end lead, and 7 "is a terminating lead. The leading end lead 7' is formed so as to be bent into the through hole 401a. It will be appreciated that the termination lead 7 "is formed and shown to be similarly bent in the through hole 401b.

The coil conductor 7 is formed on another member by plating, etching, or the like using photolithography technology.
The start lead 7 'and the end lead 7 "can be simultaneously formed in the same manner. A plurality of the coil conductors and the short-circuit conductors simultaneously formed on separate members are precisely bonded in the groove 41 by screen printing or the like. After the agent 14 is applied and fixed by pressure bonding, another member is removed, and FIG. 1 (b)
State.

In this way, the start end lead 7 'and the end lead 7 "
Since the same through hole 401 is magnetically shared,
The inductances of the two lead portions cancel each other, and the coupling coefficient of the rotary transformer does not deteriorate.
In addition, the slit-shaped connecting hole 20 connecting the two through holes 401a and 401b crosses the coil conductor 7 and is a portion to which the conductor 7 is not bonded. It does not hinder the adhesion to No. 4.

In the above description, the start and end leads of the coil conductor 7 on the rotor core 4 have been described. However, it goes without saying that the same can be performed on the stator core. Further, lead conductors 71a and 71b connected to the start end lead 7 'and the end lead 7 "of the coil conductor and provided on the core surface opposite to the opposing surface on which the coil conductor 7 is provided are also provided. The same is true.

FIG. 2 is a perspective view showing a cross section of a main part of the embodiment of the present invention. In this figure, the same or corresponding parts as those in FIG. 11 (e) are denoted by the same reference numerals.

In FIG. 2, 4 is the rotor core, and 41 is the core 4
42 is a groove for arranging the adjacent short-circuit conductor 15, 410 'is a lead drawing groove formed on the other side of the core 4 in a direction crossing the groove, and 7 is a groove. The coil conductors 401a and 401b disposed and adhered to 41 are through holes connected by the connection holes 20 in the core, 7 'is a starting end lead passed through the through hole 401a, and 7 "is passed through the through hole 401b. The terminal leads 71a and 71b are lead conductors arranged and bonded in the grooves 410 '.

The lead conductors 71a and 71b are electrically connected to the start and end leads 7 'and 7 "which are conductor foils bent in the through holes 401a and 401b by soldering or the like.

Also, the groove for the coil conductor shown in FIG. 1 and FIG.
41 and the depth of the lead conductor groove 410 'are specified to be 0.05 to 0.15 mm.

Regarding the reason for specifying the groove depth, as described above, in the method of applying the adhesive 14 for bonding the conductor, in the method of using a dispenser which has been generally used conventionally, the application amount of the order of 0.01 mm is used. Cannot be controlled, and a printing technique such as screen printing is used. When this method is applied to a surface having irregularities, the step at which the applied amount can be controlled is about 0.15 mm.

When the thickness of the conductor is about 0.03 mm, the condition for the conductor to fit in the groove is 0.05 mm or more from the thickness of the adhesive.

As described above, defining the upper limit of the groove depth can also restrict the deterioration of the coupling coefficient as the rotary transformer.

In general, the higher the coupling coefficient of the rotary transformer required for a high-performance rotary cylinder is, of course, the better, but practically, it is 0.95 or more. Conductor diameter φ0, which is a conventional rotary transformer.
Using a polyurethane wire of 20mm, with a groove depth of about 0.5mm,
When the distance between transformer cores is 0.05 mm, the coupling coefficient is 0.96
Whereas, if the core shape of the present invention was adopted, the coupling coefficient when the distance between the transformer cores was 0.05 mm was about 0.98, indicating that the characteristic improvement was remarkable. There will be.

Further, the through holes 401a, 401 shown in FIG. 1 and FIG.
As for the cross-sectional shape of b, a rectangular example is shown.

FIG. 3 is a perspective view showing a cross section of a main part of another embodiment of the present invention. In FIG. 3, (a), (b), (e)
(C) and (d) show through holes.
An example is shown in which at least one side of the cross sections of 401 and 401b presents a straight line.

The reason why the cross-sectional shape of the through-hole is also specified is as follows. Referring to FIG. 2 as an example, the conductors 7, 71a, 71b adhered in the grooves 4, 410 'provided on the surface of the core 4 are as follows.
When the conductor foils (the start lead 7 'and the end lead 7 ") corresponding to the portions guided to the through holes 401a and 401b are bent into the through hole, the edge exposed on the core surface of the through hole becomes a straight line. Since the conductor foil can be bent along the edge, the bending becomes easy, and the bending accuracy is improved, so that the production yield related to the electrical connection is greatly related. Is attached around the through-holes 401a and 401b, so that stress at the time of bending the leading end lead 7 'and the ending lead 7 "is applied to the coil conductor 7 and the conductor can be prevented from peeling off.

FIG. 4 is a perspective view showing a cross section of a main part when viewed from a surface opposite to a facing surface as a rotary transformer of an embodiment of the present invention. In FIG. 4, reference numerals 71a and 71b denote lead conductors arranged and bonded in grooves 410 ', and 7' is a through hole.
A lead end on the lead conductor side passed through 401a, 7 ″ is a terminal lead on the lead conductor side passed through through hole 401b.

In the above description, the rotor core side has been described, but it is needless to say that the same can be performed on the stator core side.

In addition, Ni-Zn and Mg-Zn ferrites are generally used as materials for the rotory transformer core, and these have high specific resistance, so it is necessary to arrange an insulating member between the core and the conductor. It goes without saying that there is no.

5 (a), 5 (b) and 5 (c) are views showing the entire rotor core of the embodiment as described above with reference to FIG. 1, wherein (a) is a plan view and (b) Is a sectional view, and (c) is a back view.

FIGS. 5 (d), (e) and (f) show the entire data core of the embodiment as described with reference to FIG. 1, wherein (d) is a plan view and (e) is a plan view. A sectional view and (f) are back views.

Such a core having a through hole portion having an irregular shape can be obtained relatively easily by the injection molding method.

FIG. 6 shows a cross section of a main part when the rotor core 4 and the stator core 8 constituting the rotary transformer of the present invention are in a state of being opposed to each other, and at least a plurality of pieces are simultaneously formed by plating, etching or the like utilizing photolithography technology. An example in which conductors such as spiral coils 7 and 9 are formed in a single layer and bonded to a core surface is shown.

〔The invention's effect〕

According to the present invention, the following effects can be expected.

(1) It is not necessary to arrange a non-magnetic material between the through-holes for leading out the lead, and it becomes unnecessary to partition between the through-holes, thereby reducing the number of cores to be manufactured.

(2) By connecting the lead extraction through-holes to each other, they become magnetically one through-hole, so that the coupling coefficient in the rotary transformer does not deteriorate.

(3) Since through-holes can be used for lead extraction, a plurality of rotary transformer conductors can be simultaneously formed only by providing one conductor layer on the same surface.

(4) Since the width of the connecting hole connecting the through holes is reduced, a highly reliable rotary transformer can be configured in which the holding strength of the conductor bonded to the core surface does not deteriorate.

(5) Since a plurality of coils and short-circuit conductors can be simultaneously bonded and formed on a rotor or a stator in units of surfaces, the effect of reducing man-hours increases as the number of conductors of the coil or short-circuit conductor increases.

(6) By defining the upper limit of the depth of the groove provided in the magnetic core, the amount of the adhesive applied to the groove provided in the magnetic core can be precisely controlled by a screen printing technique or the like. You can do it.

(7) By defining the lower limit of the depth of the groove provided in the magnetic core, at least the conductor formed by the photolithography technique and disposed in the groove is not exposed outside the groove, and the reliability is improved. High rotating transformer can be obtained.

(8) By defining the upper limit of the depth of the groove provided in the magnetic core, the variation of the coupling coefficient as a rotary transformer can be regulated, and a high-performance rotary transformer having a high coupling coefficient can be obtained. .

(9) A cross section of the through hole when a conductor foil corresponding to at least a portion of the conductor formed by the photolithography technique and corresponding to a portion guided to the through hole is bent into the through hole and an electrical connection is to be made at the through hole. By making the shape of the present invention such as a square shape, the bending becomes easy and the conductor foil is broken and the bending accuracy is improved. Therefore, the length of the conductor existing in the through hole becomes uniform, and the lead portion is formed. And a highly reliable rotary transformer can be obtained in the electrical connection of.

(10) Since the conductor width of the spiral conductor can be increased by providing the through hole outside the annular portion where the spiral conductor is arranged, a multi-channel type in which a plurality of coils are arranged. The DC resistance can be minimized, the transmission loss in a low frequency band can be reduced, and a high-performance and high-performance rotary transformer can be obtained.

(11) Further, the position where the through hole is provided is a portion where the spiral conductor is not disposed on the opposing surface of the magnetic core, and is provided in the groove provided so as to cut off the annular bank portions on both sides of the groove where the conductor is disposed. By arranging, the conductors around the start and end leads can be formed widely,
When the conductor foils corresponding to the start and end leads are bent into the through-holes, the bonding area around the bent conductor can be secured, so that the surrounding conductors can be prevented from being deformed and peeling, and the conductors can be moved out of the groove. A highly reliable rotary transformer without exposure can be obtained.

(12) At least a conductor corresponding to a portion guided to the through hole in a conductor formed by algae photolithography technology is formed in the same process as the coil conductor, and an insulator or the like is arranged between the coil conductors. Since there is no need, the number of manufacturing steps is reduced.

[Brief description of the drawings]

1 to 3 are perspective views each showing a main part of an embodiment of the present invention, and FIG. 4 is a perspective view showing a main part of the embodiment when viewed from an opposite core surface of the present invention. 5 (a), 5 (b) and 5 (c) are views showing the entire rotor core according to one embodiment of the present invention, where (a) is a plan view and (b)
Is a sectional view, (c) is a rear view, and FIGS. 5 (d), (e),
(F) is a figure which shows the whole stator core of one Example of this invention, (d) is a top view, (e) is sectional drawing,
(F) is a rear view, FIG. 6 is a cross-sectional view of a rotor core and a stator core constituting the rotary transformer of the present invention, FIG. 7 is a cross-sectional view of a main part of a rotary cylinder of a rotary magnetic head, and FIG. FIG. 9 is a cross-sectional view of the rotor core and the stator core, FIG. 9 is a perspective view showing how the lead portion is pulled out, and FIGS. 10 to 14 are diagrams showing the conventional rotor core and stator core, respectively. 1 ... magnetic head, 1 '... head base, 2 ... rotating drum, 2' ... fixed drum, 3 ... relay board (rotor side), 31 ... male relay, 32 ... female relay 4 ... Rotor core, 5 ... Rotating shaft, 6 ... Relay, 6 '... Relay plate (stator side), 7 ... Coil (rotor side), 7' ... Start lead, 7 "... ... Terminal lead, 8 ... Stator core, 9 ... Coil (stator side), 10 ... Non-magnetic member, 20 ... Connection hole, 14 ... Adhesive, 12 ... Ball bearing, 13 ... Disc, 41 , 43, 44, 45… Coil groove, 81, 83, 84, 85… Coil groove, 42… Short-circuit conductor groove, 82… Short-circuit conductor groove, 401 to 405… Through hole, 410 to 450 …… groove for lead conductor, 801 ～ 805 …… through hole, 810 ～ 850 …… groove for lead conductor,

Claims (12)

(57) [Claims] A rotor core is mounted on a rotating drum, and a stator core is mounted on a fixed drum, and a fixed drum is attached to a magnetic head on the rotating drum via the rotating transformer. A rotary magnetic head device for supplying a recording signal and transmitting a reproduction signal from the magnetic head to the fixed drum side via the rotary transformer, wherein a rotating core and a stator core constituting a rotary transformer The through-holes, which guide the winding start and end portions of the spiral conductor arranged in the provided groove to the surface side opposite to the facing surface, are connected to each other, and the width of the connection portion is equal to that of the through-hole. A rotary magnetic head device characterized in that it has a shape smaller than the outer diameter, and the connecting portion has an irregular cross section as if it were a single through hole. 2. The rotary magnetic head device according to claim 1, wherein conductors provided on the surfaces of the rotor core and the stator core constituting the rotary transformer are formed at least by a photolithography technique, and are provided on the core facing surface side. A spiral conductor and a short-circuit conductor provided for transmitting a signal, and a lead conductor provided on the surface opposite to the opposing surface to be electrically connected to the winding start and end portions of the spiral conductor. If the depth of the core groove is 0.05mm or more,
A rotating magnetic head device having a diameter of 0.15 mm or less, wherein the conductor disposed in the groove is not substantially exposed from the core surface. 3. The rotary magnetic head device according to claim 1, wherein conductors provided on the surfaces of the rotor core and the stator core constituting the rotary transformer are formed at least by a photolithography technique, and the rotor core and the stator are formed. The cross-sectional shape of each of the through-holes of the spiral conductor arranged in the groove provided on the opposing surface of the core and leading the winding start and end portions to the surface opposite to the opposing surface has a square shape. Or a rotating magnetic head device wherein at least one side of the cross section has a linear shape. 4. The rotary magnetic head device according to claim 1, wherein conductors provided on the surfaces of the rotor core and the stator core constituting the rotary transformer are formed at least by phonography technology, and the rotor core and the stator core are formed. The position of the through hole for guiding the winding start and end portions of the spiral conductor disposed in the annular groove provided on the opposite surface of the core to the surface opposite to the opposite surface is provided at the position opposite to the core. A rotating magnetic head device, wherein the spiral conductor is not disposed on the surface, and is disposed in a groove provided so as to cut off the circular ring in a circularly opposed portion forming a main magnetic circuit. 5. A magnetic head on a rotary drum side from a fixed drum side through a rotary transformer, wherein the rotor core is mounted on a rotary drum and a stator core is mounted on a fixed drum among the rotor core and the stator core constituting the rotary transformer. And a read signal from the magnetic head is transmitted to the fixed drum side via the rotary transformer. The opposed surface of the rotor core and the stator core constituting the rotary transformer Spiral conductors and short-circuit conductors that are provided on the side and transmit signals, and lead conductors that are electrically connected to the winding start and end portions of the spiral conductor and are provided on the surface opposite to the facing surface. The rotating magnetic head device, wherein the depth of the core groove is 0.05 mm or more and 0.015 mm or less. 6. A rotary magnetic head device according to claim 5, wherein a conductor disposed in a groove provided on a surface of a rotor core and a stator core constituting a rotary transformer is formed at least by a photolithography technique. A rotating magnetic head device, wherein the conductor disposed on the core is not substantially exposed from the surface of the core. 7. A rotary transformer comprising a rotor core and a stator core, wherein, in one or both of the rotor core and the stator core, a spiral conductor disposed in a groove provided on a surface facing the core. Through holes that guide the winding start and end portions to the surface opposite to the opposing surface are connected to each other, and the width of the connecting portion is smaller than the outer diameter of the through hole, as if by the connecting portion. A rotating tosens with an irregular cross section like one through hole. 8. The rotary transformer according to claim 7, wherein at least one of the rotor core and the stator core of the rotary transformer composed of the rotor core and the stator core has a surface that faces the rotor core and the stator core. The spiral conductor is formed by at least phosography technology, and is provided on the facing surface side of the rotor core and the stator core to transmit a signal,
And the depth of the core groove, which is electrically conductive with the winding start and end portions of the spiral conductor and is provided with the lead portion conductor provided on the surface opposite to the facing surface, is 0.05 mm or more and 0.15 mm
A rotating transformer, wherein the conductor disposed in the groove is not substantially exposed from the surface of the core. 9. The rotary transformer according to claim 7, wherein conductors provided on surfaces of the rotor core and the stator core constituting the rotary transformer are formed at least by a photolithography technique, and the rotor core and the stator core are formed. The cross-sectional shape of each of the through-holes of the spiral conductor arranged in the groove provided on the opposite surface of the through-hole leading the winding start and end portions to the surface opposite to the opposite surface is rectangular. Or at least one side of the cross section is a straight line. 10. The rotary transformer according to claim 7, wherein conductors provided on the surfaces of the rotor core and the stator core are formed at least by a photolithography technique, and provided on opposing surfaces of the rotor core and the stator core. The position of the through-hole for guiding the winding start and winding end portions of the spiral-shaped conductor disposed in the formed annular groove to the surface side opposite to the opposing surface is provided at the opposing surface of the core. A rotary transformer in which a ring-shaped conductor is not disposed, and is disposed in a groove provided so as to cut off the ring in a ring-shaped opposing portion constituting a main magnetic circuit. 11. A spiral conductor provided on one or both of the rotor core and the stator core of the rotary transformer comprising the rotor core and the stator core, the spiral conductor being provided on a side facing the rotor core and the stator core to transmit a signal. And a short-circuit conductor, and a lead portion conductor which is electrically conductive to the winding start and end portions of the spiral conductor and is provided on the surface opposite to the facing surface, the depth of the core groove is 0.05. A rotary transformer characterized by being not less than 0.1 mm and not more than 0.15 mm. 12. A rotary transformer according to claim 11, wherein a conductor disposed in a groove provided on a surface of said rotor core and said stator core constituting said rotary transformer is formed at least by a photolithography technique. Wherein the conductor disposed on the core is not substantially exposed from the surface of the core.