JP2908609B2 - Rotating magnetic head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary magnetic head device for recording a signal on a magnetic tape as a recording medium and reproducing a signal recorded on the magnetic tape, and in particular, a rotary transformer used in the device. Regarding improvement.

[0002]

2. Description of the Related Art An example of a conventional rotary magnetic head device used for an information recording / reproducing apparatus such as a video tape recorder (VTR) and a digital audio tape recorder (DAT) will be described with reference to FIG. As shown in FIG. 5, the rotary magnetic head device 100 is roughly divided into a rotating part above the drawing and a fixed part below the drawing. The rotating part is
A rotating drum 105 is fixed to the rotating shaft 150. A head dime 107 as a support member is fixed to a lower end of the rotating drum 105.
A magnetic head 120 is attached to the peripheral edge of the head.
On the other hand, the fixing unit has a substrate 101 and a fixing drum 103 fixed to the substrate 101. A stator core 220 and a rotor core 210 are provided at the upper end of the fixed drum 103 and the lower end of the rotary drum 105, respectively, facing each other. The combination of the rotor core 210 and the stator core 220 forms a so-called flat facing rotary transformer 200.

[0003] Rotor core 210 and stator core 22
0, the inner coil 211 as a primary winding,
Outer coil 215 and inner coil 2 as secondary winding
21, an outer coil 225 is provided.

[0004]

However, the following problems have arisen in the conventional rotary transformer 200, particularly in the laying structure of the primary winding of the rotor core 210.

That is, as shown in FIGS. 6 to 8,
On one surface of rotor core 210, grooves 212 and 216 for laying inner coil 211 and outer coil 215 are provided.
Are formed, and the inner coil 211 and the outer coil 215 are laid in these grooves. And the inner coil 21
The lead wire portion 211a connected to the outer coil 215 and joined to a magnetic head (not shown) is formed of a polyethylene film or the like at the intersection C with the outer coil 215 to prevent mutual contact between the coils. I was in between. Therefore, the depth of the groove for laying the coil is required to be twice the thickness of the coil plus the thickness of the polyethylene film. Further, when laying the coil, as shown in FIG. The two coils have a two-stage structure, particularly in this example, the inner coil 211 is on the lower side, and the inner coil 211 has a groove depth that is more than necessary, and is installed at a deep position away from the vicinity of the surface layer of the rotor core 210, thereby increasing leakage magnetic flux. However, there has been a problem that the coupling coefficient between rotor core 210 and stator core 220 is reduced.

The present invention has been made under such circumstances, and an object of the present invention is to reduce a leakage magnetic field and improve a coupling coefficient between a primary coil and a secondary coil. .

[0007]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a rotating magnetic head and a rotary transformer as a signal transmitting means between the rotating magnetic head and a stationary circuit. In the rotating magnetic head device provided,
The rotary transformer is of a planar facing type having a disk-shaped rotor core and a stator core facing each other. The rotor core and the stator core are provided with an inner coil and an outer coil concentrically, respectively, and an inner coil and an outer coil of the rotor core are provided. Is made of a thin metal plate, and a lead wire portion connected to the inner coil and drawn out and electrically connected to the magnetic head is formed at a crossing portion with the outer coil.
Disposed so as to be partially separated from the outer coil.
At the same time, except for the intersection, the coil surface of the outer coil
And the coil surface of the inner coil are disposed substantially in the same plane.
Characterized in that it is.

[0008]

The lead wire portion of the inner coil is disposed while being partially separated from the outer coil only at the intersection with the outer coil ,
In other parts, the coil surface of the outer coil and inner coil
Since what was is disposed in the substantially same plane, the inner coil and the outer coil can be installed in the vicinity of the surface of the rotor core, leakage
The leakage magnetic field becomes smaller. Therefore, the coupling coefficient between the primary coil and the secondary coil is significantly improved. Furthermore, it is unnecessary to insert an insulator, and workability is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the rotating magnetic head device of the present invention
This will be described with reference to FIGS. As shown in FIG. 1, a rotating magnetic head device 1 according to the present invention
And a fixing portion F shown in the lower part of the drawing.
The rotating unit R includes a rotating shaft 5 and a rotating drum 10 fixed to the shaft 5.

A head dime as a support member 11 is fixed below the peripheral edge of the rotary drum 10, and magnetic heads 12, 12 are mounted on the upper end of the support member 11 (one magnetic head 12). Are arranged symmetrically with respect to the other magnetic head 12, but are not shown in the drawing). On the other hand, to the lower end portion 10a of the rotary drum 10, a plane facing type rotary transformer 20, in particular, a rotor core 21 constituting a part thereof is bonded and fixed. Incidentally, the stator core 31 installed facing the rotor core 21 is fixed to a fixed drum 50 of a rotating portion F described later.

On the lower surface of the rotor core 21, grooves 22 and 26 for concentrically providing an inner coil 23 and an outer coil 27 as primary coils are formed (FIGS. 2 and 4). , 26, one each
Inner coil 23 and outer coil 2 as secondary coil
7 are arranged. Inner coil 23 and outer coil 27
Is formed from a one-turn sheet metal. The lead wire portion 24 (lead portion) which is connected to the inner coil 23 and is drawn outward and indirectly joined to the magnetic head is
As shown in FIG. 2 and FIG. 3, they are arranged so as to dive below while being partially separated at the intersection C with the outer coil 27. That is, as shown in FIG. 3, the lead wire portion 24 has a portion 24 a having a height level similar to that of the outer coil 27, and a relief portion 24 b which is retracted downward to prevent contact with the outer coil 27. With such a structure, both the inner coil 23 and the outer coil 27 can be installed in the vicinity of the surface layer of the rotor core 21, so that the leakage magnetic flux which has conventionally occurred can be reduced, and the primary side coil and the secondary coil The coupling coefficient with the side coil is significantly improved.

On the other hand, a lead wire portion (lead portion) is similarly drawn out from the outer coil 27 and indirectly joined to another magnetic head 12. However, in this case, the lead wire portion 28 (lead portion) does not intersect with the inner coil 23, and there is no need to form a so-called escape portion. A method of indirectly connecting the lead wire portion (lead portion) to the magnetic head will be described with reference to FIG. FIG. 4 is a view of the rotor core 21 as viewed from the back side. As can be seen from this figure, the leading end direction of the lead wire portion 28 (lead portion) is bent in the direction of the upper surface of the rotor core 21 (since FIG. 4 is a view seen from the back surface direction, the lower side of the figure is the upper surface), The distal end portions 28a, 28a are expanded to the left and right, respectively, and are joined to the flat so-called rounds 13, 13 formed on the lower surface of the support member 11. As this joining method, soldering is generally used. However, by using a coil (particularly, a plate having a spring property) as in the present invention, it is possible to perform a simple press-connecting method by urging. In this case, the work of soldering is omitted, and the productivity is improved.
As shown in FIG. 4, head windings 14 are connected to rounds 13. By the way, the leading end portion of the lead wire portion 28 (lead portion) is completely bent to the upper surface side of the rotor core 21 (FIG. 4 is a diagram viewed from the back surface, the lower side of the drawing is the upper surface), and the rotor core 21 is rotated. It is also possible to make this portion close to the upper surface side of 21 and make this portion a round.

On the other hand, as shown in FIG. 1, the fixing portion F has a cylindrical fixed drum 50 fixed to a base 60, and the fixed drum 50 constitutes a part of the rotary transformer 20. The stator core 31 is fixed. The stator core 31 is disposed so as to face the rotor core 21 in a non-contact manner, and faces the primary coil of the rotor core 21.
Inner coil 33 and outer coil 3 as secondary coils
7 are arranged concentrically. By the way, the rotary transformer 20
The fixed drum 5 fixed by receiving the information signal read from the magnetic tape T by the magnetic head 12 through the wiring
It plays a role of transmitting the signal from the fixed drum 50 to the magnetic head 12 via a wiring. Also,
In the present embodiment, the drive unit for rotating the rotating unit R, particularly the fixed drum 10, is a drive system having the rotary magnet 80 and the stator core member 90, but is not limited thereto.

In the present embodiment, the lead wire from the inner coil is sunk downward at the intersection with the outer coil. Conversely, a part of the outer coil is slid down at the intersection. Needless to say, it may be done.

[0015]

The rotary transformer used in the present invention is of a flat facing type having a disk-shaped rotor core and a stator core facing each other. The rotor core and the stator core are provided with an inner coil and an outer coil, respectively. The coil is provided concentrically, and the inner coil and the outer coil of the rotor core are made of a thin metal plate. The lead wire connected to the inner coil, drawn out and joined to the magnetic head is the outer wire.
Arranged so that it is partially separated only at the intersection with the coil
Other than the crossover part,
The coil surface of the inner coil and the coil surface of the
It is arranged . Therefore, the leakage magnetic field generated conventionally is extremely small, and the coupling order between the primary coil and the secondary coil is significantly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotary magnetic head device according to the present invention.

FIG. 2 is a plan view showing a state of wiring of a primary coil of a rotor core used in the present invention.

FIG. 3 is a sectional view taken along a line III-III in FIG. 2;

FIG. 4 is a schematic perspective view for explaining a method of electrically connecting an outer coil and a magnetic head.

FIG. 5 is a sectional view of a conventional rotary magnetic head device.

FIG. 6 is a plan view showing a state of wiring of a primary coil of a conventional rotor core.

7 is a drawing in which only an inner coil and an outer coil as primary windings are extracted and drawn from the VII-VII direction of FIG. 6;

FIG. 8 is a perspective view showing a schematic relationship between a groove formed in a rotor core and an outer coil laid in the groove.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 ... Rotary transformer 21 ... Rotor core 23 ... Inner coil 24 ... Lead wire part 27 ... Outer coil 31 ... Stator core C ... Crossover part

Claims (3)

(57) [Claims] 1. A rotating magnetic head device comprising: a rotating magnetic head; and a rotating transformer as a signal transmitting means between the rotating magnetic head and a circuit on a stationary side. The rotor core and the stator core are concentrically provided with an inner coil and an outer coil, respectively. The inner coil and the outer coil of the rotor core are formed of a thin metal plate. A lead wire portion which is connected and pulled out to be electrically connected to the magnetic head has an intersection with the outer coil.
It is arranged so that it is only partially separated from the outer coil at the fork.
And the coil surface of the outer coil and the inner surface except for the intersection.
A rotating magnetic head device, wherein a coil surface of a side coil is disposed in substantially the same plane . 2. The lead wire section has an intersection with the outer coil.
Only at the fork, move downward while partially separating from the outer coil.
The inner coil and the outer coil are disposed so as to dive
2. The rotary magnetic head device according to claim 1, wherein the magnetic head is installed near a surface layer of the rotor core . 3. An outer coil according to claim 1 , wherein said outer coil has an intersection with said lead wire portion.
At the fork only, the part below the lead wire part
And the inner coil and the outer coil are
2. The rotary magnetic head device according to claim 1, wherein the rotary magnetic head device is provided near a surface layer of the rotor core .