JPH06309604A - Earth structure between drum for rotary magnetic head device and rotary transformer - Google Patents

Abstract

PURPOSE:To provide an earth structure between a drum for a rotary magnetic head device and a rotary transformer capable of improving productivity, cost reduction and the reliability of earth by eliminating force-inserting and soldering work. CONSTITUTION:In the earth structure between the fixed drum 11 for the rotary magnetic head device 10 and the rotary transformer 12 mounted on the drum 11, the fixed drum 11 and the substrate 31 of the rotary transformer are screwed by interposing an elastic member 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground structure for a rotary transformer and a drum for a rotary magnetic head device used for recording / reproducing for a VTR, for example.

[0002]

2. Description of the Related Art For example, as shown in FIG. 6, a rotary magnetic head device used for recording and reproducing a VTR has a cylindrical upper drum 8 to which a magnetic head (not shown) is fixed, and substantially the same as the upper drum 8. And a cylindrical lower drum 1 having a diameter.

The upper drum 8 is a rotary drum which is fixed to a rotary shaft 7 and rotates as the rotary shaft 7 is rotated by a predetermined driving means (not shown). A magnetic head (not shown) is fixed to the lower surface of the rotary drum 8 so as to slightly project toward the outer circumference.

As a result, this magnetic head is wound around the outer periphery of the rotary drum 8 and helically scans a magnetic tape running diagonally to record or reproduce information signals.

The lower drum 1 is supported on a rotary shaft 7 by a rotary bearing (not shown).
It is configured as a fixed-side drum that does not rotate when it rotates.

As shown in the drawing, a disc-shaped rotary transformer core 2 (stator side) is mounted on the lower drum 1 with a predetermined winding, and is mounted on the lower surface of the upper drum 8. It faces the rotor-side core (not shown) with a predetermined gap.

The rotor core of the upper drum 8 is connected to the magnetic head via a head amplifier (not shown). On the other hand, the stator core 2 of the lower drum 1 is connected to the signal processing circuit on the device body side.

As a result, the rotor core and the stator core 2 constitute a rotary transformer, and the recording or reproducing signal or the like is exchanged between the magnetic head and the main body of the apparatus in a non-contact manner.

In such a magnetic head device, a ground (GND) is provided between the lower drum 1 and the core 2 of the rotary transformer as a measure against crosstalk.

That is, as shown in FIG. 7, the lower drum 1
A ring-shaped molding bush 4 shown in FIG. 8 is press-fitted into the hole 3 formed in advance, and the land or substrate 5 of the rotary transformer 2 and the projecting piece 4a extending integrally and obliquely from the molding bush 4 are formed. It is grounded by being attached with solder 6.

[0011]

However, when the molded bush 4 is used for grounding, not only the workability of soldering the press-fitting bush 4 is poor, but also the solder is defective, that is, the protruding piece 4a. On the other hand, when a large amount of solder is added, there is a problem in that the contact of the press-fitting bush, the spring property at X, or the instability of the ground due to the decrease in spring property occurs.

In view of the above-mentioned problems, the present invention can improve productivity, reduce cost and improve reliability of ground by reducing the work of press-fitting and soldering, and the drum and rotary for a rotary magnetic head device. The purpose is to provide a ground structure with a transformer.

[0013]

According to the present invention, there is provided a grounding structure for a fixed drum for a rotary magnetic head device and a rotary transformer mounted on the drum, wherein the fixed drum and the rotary transformer are provided. The board of
This is achieved by an earth structure of the rotary magnetic head device drum and the rotary transformer, which is screwed with an elastic seat member interposed.

Preferably, the elastic member is a seat spring.

More preferably, the seat spring is made of a conductive material, and an upper portion formed in a ring shape abuts on a ground contact surface formed on a substrate of the rotary transformer, and from this upper portion in a circumferential direction. In addition, the tip ends of the plurality of legs that are inclined and extended downward may be in contact with the upper surface of the fixed drum.

[0016]

According to the above construction, since the fixed drum and the substrate of the rotary transformer are fixed by screws with the elastic member interposed, it is not necessary to solder them. For this reason, the problems associated with soldering unlike the conventional case do not occur.

[0017]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes.

FIG. 1 shows a rotary magnetic head device to which a preferred embodiment of the present invention is applied. The rotary magnetic head device drum 10 is for performing at least one of recording a signal on a recording medium such as a VTR tape and reproducing a signal from the recording medium.

In the figure, the rotary magnetic head device 10 is
A cylindrical upper drum 13 to which the magnetic head 14 is fixed,
A cylindrical lower drum 11 having a diameter substantially the same as that of the upper drum 13 is provided.

The upper drum 10 is fixed to a rotary shaft 17 via a flange 15. The rotary drum 17 rotates as the rotary shaft 17 is rotated by the action of motors (magnets) 18 and 19. Is. The magnetic head 14 is fixed to the lower surface of the rotary drum 8 so as to slightly project toward the outer circumference.

As a result, the magnetic head 14 is wound around the outer periphery of the rotary drum 13 by a predetermined angle, and a magnetic tape (not shown) running obliquely is helically scanned to record or reproduce an information signal. Has become.

The lower drum 11 is supported by a rotating shaft bearing 22 with respect to the rotating shaft 17, and is constructed as a fixed drum that does not rotate with the rotating shaft 17 even if the rotating shaft 17 rotates. As shown in the figure, a disk-shaped rotary transformer core 12 (stator side) is mounted on the lower drum 11 with a predetermined winding, and is mounted on the lower surface of the upper drum 13 on the rotor side. It faces the core 16 with a predetermined gap.

Here, the rotor core 16 of the upper drum 13
Are connected to the magnetic head 14 via a head amplifier (not shown). On the other hand, the stator core 1 of the lower drum 11
2 is connected to the signal processing circuit on the device body side.

Thus, the rotor core 16 and the stator core 12 constitute a rotary transformer, and the recording or reproducing signal or the like can be exchanged between the magnetic head 14 and the main body of the apparatus in a non-contact manner.

Further, the rotary magnetic head device 1 of this embodiment
In No. 0, as a measure against crosstalk, a ground (GND) is provided between the lower drum 11 and the core 12 of the rotary transformer by the following ground structure 30.

FIG. 2 is an enlarged view of the vicinity of the portion A of FIG. In the figure, a substrate 31 is fixed to the lower surface of the stator core 12. A glass epoxy substrate, for example, is preferably used as the substrate 31, and as shown in FIG. 3, the substrate 31 has a through hole and a land 31a for grounding contact formed by forming a conductive pattern around the through hole. It is provided.

A screw hole 11a is provided on the upper surface near the periphery of the stator core 11, and the screw hole 11a is provided at a position corresponding to the land 31a of the substrate 31. Using this hole, a seat spring 33 is interposed between the lower drum 11 and the substrate 31, and the substrate 31 is moved to the lower drum 1.
1 is fastened and fixed by screws 35.

The seat spring 33 is made of, for example, a metal material,
In particular, a plate material made of spring phosphorus bronze or the like is punched out to have a shape as shown in FIG. 4, which has excellent conductivity and elasticity. As shown in FIG. 4, the seat spring 33 includes a ring-shaped upper portion 36 having a through hole for passing a screw in the center, and a plurality of leg portions integrally extending from the upper portion 36 and downward in the drawing. 37 are provided.

Therefore, utilizing this seat spring 33,
As shown in FIG. 2 and FIG.
When the lower drum 11 and the lower drum 11 are fastened, the substrate 31 is held in a fastened state by a predetermined pressure by the elastic force of the seat spring 33. Moreover, when the screw 35 is fastened to the screw hole 11a of the lower drum 11, the seat spring 33 moves the screw 35
Since a predetermined elastic force is exerted by being interposed between the lower drum 11 and the lower drum 11, the substrate 31 will not be damaged by tightening the screw 35.

Further, this ground structure 30 does not require soldering work as in the conventional case. That is, the seat spring 33 is sandwiched between the substrate 31 and the lower drum 11, and the screw 3
Drum 11 and core 1 can be easily done by just tightening 5.
2 (Rotary transformer) can be grounded.

Therefore, it is possible to obtain an extremely reliable and highly reliable ground structure without any problems associated with soldering, for example, the solder is peeled off and the ground function is lost.

The present invention is not limited to the above embodiment. For example, the elastic member is not limited to the shape shown in FIG.
Any material may be used as long as it is formed of a conductive elastic material that is interposed between the substrate 31 and the lower drum and has a portion through which screws are passed.

[0033]

According to the present invention, a drum for a rotary magnetic head device and a rotary transformer capable of improving productivity, reducing cost and improving reliability of ground by reducing press-fitting and soldering operations. It is possible to provide the earth structure.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a rotary magnetic head device to which a preferred embodiment of the present invention is applied.

FIG. 2 is an enlarged view showing a portion A of FIG.

FIG. 3 is a diagram showing an earth contact land of the substrate of FIG.

FIG. 4 shows an example of a washer of the ground structure of FIG. 1 (a).
Plan view, (b) side view.

5 is a schematic plan view of the enlarged portion of FIG.

FIG. 6 is a schematic cross-sectional view in the vicinity of a lower drum of a conventional rotary magnetic head device.

FIG. 7 is a schematic sectional view showing a ground structure of a rotary transformer and a drum of a conventional rotary magnetic head device.

FIG. 8 is a plan view of a molding bush used in the ground structure of FIG.

[Explanation of symbols]

 10 Rotating Magnetic Head Device 11 Lower Drum (Fixed) 12 Stator Core 13 Upper Drum 16 Stator Core 31 Substrate 33 Seat Spring 35 Screw

Claims (3)

[Claims] 1. A fixed drum for a rotary magnetic head device,
In a ground structure for a rotary transformer mounted on this drum, a drum for a rotary magnetic head device, characterized in that the fixed drum and the substrate of the rotary transformer are screwed together with an elastic member interposed. Ground structure with rotary transformer. 2. The ground structure for a rotary magnetic head device drum and a rotary transformer according to claim 1, wherein the elastic member is a seat spring. 3. The seat spring is made of a conductive material, and the ring-shaped upper portion abuts on a ground contact surface formed on the substrate of the rotary transformer, and the ring-shaped upper portion extends in the circumferential direction. 3. The ground structure for the rotary magnetic head device drum and the rotary transformer according to claim 2, wherein the tips of a plurality of legs extending downwardly and in contact with the upper surface of the fixed drum are in contact with each other. .