JPS6023768Y2 - Head support device for rotating magnetic head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head support device for a rotating magnetic head device used in video cheap recorders and the like.

First, before explaining the present invention, we will introduce a video tape recorder (
Hereinafter referred to as VTR.

) The rotating magnetic head device used in the following will be briefly explained.

FIG. 1 is a schematic perspective view showing an example of a rotating magnetic head device.

This rotating magnetic head device 1 has a rotating disk 2 that rotates in the direction of arrow A, and is fixed to the chassis of a VTR or the like at the upper and lower positions of the rotating disk 2.
Lower drums 3 and 4 are arranged.

The motor 5 rotates the rotary disk 2 .

The magnetic tape 6 is wound obliquely around the upper and lower drums 3 and 4 within an angle range of about 180 degrees, and is driven to run in the direction of arrow B.

In order to keep the position of the magnetic tape 6 constant with respect to the rotary head device 1, guide poles 7.8, a stepped portion 9 of the lower drum, etc. are provided.

For example, two magnetic heads are used, and these are mounted on the rotating disk 2 at an angle of 180 degrees to each other.

The tip of the head chip 11 of the magnetic head slightly protrudes from the outer peripheral surface of the drums 3, 4, etc., and comes into sliding contact with the magnetic tape 6, thereby recording and reproducing video signals.

By such a rotating magnetic head, recording tracks T as shown in FIG. 2 are sequentially formed obliquely on the magnetic tape 6.

These recording tracks T are recorded when the magnetic tape 6 is at a steady speed υ
.

During normal playback, the head chip 11 moves 1° in a straight line, so that normal video signal playback can be performed.

However, in playback of still images (still playback), slow motion playback, etc., the traveling speed of the magnetic tape 6 in the direction of arrow B is the steady speed υ.

If this is different, the trajectory of the head chip 11 will deviate from one recording track T, for example like the straight line 11 in FIG.

Further, due to problems with the mechanical accuracy of the rotary magnetic head device 1, the head chip 11 often moves at a position deviated from the center position of the recording track T, as shown by the curve 1° in FIG. 2, for example.

In order to compensate for these deviations from the recording track T,
A head support device is known that uses an electro-mechanical transducer such as a bimorph to displace the head chip 11 in the direction of arrow C in FIGS. 1 and 2.

That is, FIG. 3 is a perspective view for explaining a conventional example of the head support device 10 using the bimorph plate 12, and shows a state where the head support device 10 is mounted on the rotating disk 2. As shown in FIG.

This head support device 10 attaches and fixes a head chip 11 to one end of a bimorph plate 12, and attaches the other end of this bimorph plate 12 to a platform of a head base 13, etc.
It is configured by being adhesively fixed using an adhesive 14.

The surface electrode of the bimorph plate 12 and the lead wire 15 are electrically connected by solder 16.

In such a head support device 10, the bimorph plate 12
Since it is adhesively fixed on the head substrate 13, once it is fixed, it cannot be removed, and the fixing position cannot be adjusted or the bimorph plate 12 cannot be replaced for repair.

Further, since the lead wire 15 is soldered to the bimorph plate 12, the work is troublesome, and the heat of melting the solder disturbs the polarization of the bimorph plate 12, causing characteristic deterioration, which is not preferable.

Next, FIGS. 4 and 5 show another conventional head support device 20, in which a head chip 21 is attached to one end of a substantially trapezoidal bimorph plate 22. FIG.

The other end of this bimorph plate 22 is fixedly attached to the table-shaped portion of the head base 23 with screws 24.

Further, the lead wire 25 is electrically connected to a metal contact terminal plate 27 by solder 26, and this connection terminal plate 27
are in contact with and electrically connected to both surface electrodes of the bimorph plate 22.

In this case, an insulating plate 28 is inserted to maintain insulation from the head base 23 and the like, and the screw 24 is tightened and fixed via a stop plate 29.

In such a head support device 20, the bimorph plate 22
Processing such as providing a hole for inserting the screw 24 is required at the other end of the bimorph plate 22 and the high-speed vibration of the head support device 20 itself due to screw fixation. There is a drawback that the screw 24 gradually loosens when used for a long time due to vibrations during rotation and the like.

One of the reasons for this is that since the metal contact terminal plate 27 is used, even if there is slight loosening, a gap is created on the contact surface, and the coefficient of friction is also low, making it easy for misalignment to occur.

Moreover, soldering work is required for electrically connecting the lead wires 25, which also has the drawback of increasing the number of steps.

The present invention has been made to eliminate the above-mentioned drawbacks of the conventional technology, and at the same time as the assembly work, electrical connection of bimorph boards etc.
It is an object of the present invention to provide a head support device for a rotating magnetic head device in which electrical connection work between a mechanical transducer element and a lead wire is performed, reducing assembly man-hours and increasing mass production efficiency.

Another object of the present invention is to enable electrical connections to be made without processing the electro-mechanical transducer such as lead wires, and to prevent damage and characteristic deterioration of the electro-mechanical transducer.

Still another object of the present invention is to stably support the electro-mechanical transducer and provide a long service life.

Still another object of the present invention is to allow the electro-mechanical transducer to be easily removed even after it is fixedly supported on the head base, thereby facilitating position adjustment and parts replacement.

Hereinafter, preferred embodiments of the device according to the present invention will be described in detail with reference to FIGS. 6 to 10.

FIG. 6 is an exploded perspective view of the head support device 30 according to the embodiment seen from the bottom side, and FIG. 7 is a side view of the head support device 30 in an assembled state.

6 and 7, the head support device 30 of the rotating magnetic head device has a bimorph plate 32 with a head chip 31 attached to one end, a closed end 33a, and an open end 33b. A conductive member for electrically connecting a U-shaped head base 33 made of an elastic material, an insulating member 34 for regulating the position of the bimorph plate 32, and a surface electrode lead wire 35 of the bimorph plate 32. rubber 3
I have been admonishing this since 6.

First, the head chip 31 has a coil wound around a magnetic core such as ferrite, and performs electric-magnetic conversion to record and reproduce video signals on a magnetic tape.

Next, the bimorph plate 32 is a type of electro-mechanical conversion element, and is made of, for example, PZT (PbZr03
Electrodes are adhered to both sides of a plate made of a solid solution of PbTiO3 and PbTiO3, and two such plates are bonded together so that their polarization directions are opposite to each other.

If a voltage is applied between both electrodes on the outside of the bimorph plate 32 to form an electric field, the direction indicated by the arrow C, which is approximately in the gap direction of the head chip 31, will change depending on the strength and direction of this electric field.
A directional displacement amount and direction are determined.

Instead of such a bimorph plate 32, a monomorph plate or other electro-mechanical conversion element may be used.

Next, the head base 33 is made of an elastic material such as phosphor bronze, steel, or stainless steel, and has a cross section U having a pair of plate-like arms.
The open ends 3 of these plate-like arms are shaped like letters.
An elastic force (see arrow) is applied in the direction in which the parts 3b approach each other (close direction).

In order to resist this elastic force and bias the open end portions 33b in a direction in which they separate from each other (opening direction), a removable screw 33c is used in this embodiment.

That is, as shown in FIGS. 6 and 7, a screw hole is formed in one arm of the U-shaped head base 33, a screw 33c is screwed into the hole, and the tip of this screw 33c is inserted into the other arm. After contacting the inner wall of the arm, turn the screw 33c further and follow the arrow E.
If the head base 30 is moved in the direction shown in FIG.

Here, on the mutually opposing surfaces of the pair of open ends 33b,
Recesses 33d for positioning the insulating member 34 are provided respectively.

Further, the closed end 33a has an opening 3 through which the head chip 31 attached to one end of the bimorph plate 32 is inserted.
3e is formed.

Such a head base 33 may be used as a rotating disk of a rotating magnetic head device or the like (these are the same as conventional ones, so please refer to FIGS. 1, 3, etc.).

), for example, a stepped circular hole 33f is formed in one arm of the head base 33 (see FIG. 9).
, a nut member 33g having an external dimension slightly larger than this circular hole 33f is lightly press-fitted into the circular hole 33f through a circular hole 33h provided in the other arm of the head base 33;
Connect them so that they can rotate without coming apart.

Next, the insulating member 34 is made of synthetic resin such as polycarbonate or polyamide, and has a recess 34a for fitting and supporting the other end of the bimorph plate 32.

A pair (two) of the insulating members 34 are arranged on both sides of the bimorph plate 32, but the recesses 34a may be provided only on one of them.

Further, the insulating member 34 is formed with a groove 34b1 for guiding the lead wire 35 and a recess 34c for fitting the conductive rubber 36 therein.

Next, the conductive rubber 36 is connected to the lead wire 35 and the bimorph plate 32.
This electrically connects the surface electrode of the

That is, the lead wire 35 is guided to the recess 34c into which the conductive rubber 36 is fitted, and is guided at least to the recess 34c.
The conductor of the partial lead wire 35 is exposed.

Therefore, an electrical connection can be established simply by bringing the conductive rubber 36 into contact with the surface of the bimorph plate 32 while fitting into the recess 34c.

The conductive rubber 36 used here may be any conductive elastic material.

To explain how to assemble the head support device 30 having the above configuration, first, insert the nut member 33g into the circular hole 33.
The head base 33 is lightly press-fitted into the stepped circular hole 33f through the hole 33h, and the screw 33c is advanced in the direction of the arrow E to bias the open end 33b of the head base 33 in the opposite direction to the arrow.

At almost the same time, in the insulating member 34, the lead wire 35 is guided to the recess 34c via the groove 34b, and then
The conductive rubber 36 is fitted into the recess 34c, and the other end of the bimorph plate 32 is guided and positioned into the recess 34a.

In this state, the bimorph plate 32 is
is inserted into the internal gap of the head base 33, and the head chip 31 at one end of the bimorph plate 32 is inserted into the opening 33e.

At this time, the insulating member 34 is connected to the open end 3 of the head base 33.
It is guided and positioned by the recess 33d of 3b.

In this way, the bimorph plate 32 and the head base 33 are positioned via the insulating member 34.

Next, when the screw 33c is retreated in the opposite direction to the arrow E, an elastic force in the direction of the arrow is applied to the open end 33b of the head base 33, and this elastic force causes the bimorph plate 3 is supported under pressure.

8 and 9 show a state in which the thus assembled head support device 30 is fixedly attached to a rotating disk 2' etc. of a rotating magnetic head device.
The figure is a plan view, and FIG. 9 is a sectional view taken along the line X--X in FIG. 8.

That is, in this embodiment, after removing the screw 33c, the fixing screw 33k is inserted from the back side of the rotary disk 2' and screwed into the screw hole of the nut member 33g.

Since the nut member 33g is rotatably press-fitted into the stepped circular hole 33f, the position of the nut member 33g can be finely adjusted by rotating the head base 33.

Furthermore, in order to immovably fix the head base 33, for example, a screw may be inserted from the back side of the rotary disk 2' into the screw hole after removing the screw 33c, and the head base 33 may be screwed and fixed. A hole 33i is formed to pass through the upper and lower arms of the head base 33.The screw 3 is inserted through this hole 33i.
3j and fix it to the rotating disk 2' with screws.

FIG. 10 shows another embodiment, in which the screw 33 is
A wedge 3B is used instead of c to bias the open end 33b in the direction opposite to the arrow.

For this wedge 38, the tip of a flathead screwdriver may be used, for example, or a special tool may be made.

Since the other configurations are similar to those of the embodiment shown in FIGS. 6 to 9, the same reference numerals will be given to the same parts and the explanation will be omitted.

Note that the screw 33c and the wedge 38 may be used together, and various other means can be used to bias the open end 33b in the direction opposite to the arrow mark against the elastic force of the head base 33.

According to such a head support device 30, the conductive rubber 36 is pressed into contact with the lead wire 35 and the surface electrode of the bimorph plate 32 at the same time as the bimorph plate 32 is fixedly supported on the head base 33 via the insulating member 34. However, since the electrical connection is made, there is no need for a separate connection operation, unlike conventional soldering, and the number of assembly steps can be reduced.

Further, since the conductive rubber 36 has a large frictional resistance, it is possible to effectively prevent the bimorph plate 32 from shifting due to vibration or the like.

In addition, the bimorph plate 32, which has been previously formed into a trapezoidal shape or the like, can be assembled as is, and drilling and soldering are not required.

This is because bimorph plates are ceramic and brittle, so drilling them can be difficult, and when soldering, heat treatment disrupts the polarization of the bimorph plates, deteriorating their properties. It can be seen that this greatly contributes to facilitation and improved characteristics.

Furthermore, since the bimorph plate 32 and the conductive rubber 36 are simply in pressure contact, even after the bimorph plate 32 is fixedly supported on the head base 33, the screws 33c and the wedges 38
Only the bimorph plate 32 can be easily removed by using a tool such as the bimorph plate 32, and even if parts are replaced, there is no need for electrical connection work such as soldering again.

Therefore, maintenance and repair (so-called after-sales service) after the sale of the VTR can be carried out efficiently.

In addition, as an effect of this embodiment, the relative positioning of the bimorph plate 32 and the head base 33 can be easily performed by the recess 33d of the head base 33 and the recess 34a of the insulating member 34, and the bimorph When fixing the plate 32 at a proper position, there is no need for a conventional jig or the like.

Moreover, when supporting and fixing, loosen the screw 33c,
A constant tightening force (elastic force in the direction of the arrow) can be obtained by a simple operation such as removing the wedge 38.

Furthermore, the head base 33 has a U-shaped cross section, and the bimorph plate 32 is arranged in the inner space of this U-shape, so that a protective effect is obtained, and when the head support device 30 is handled by hand. In addition, the bimorph plate 32 is less likely to get scratched or dirty.

As is clear from the above description, the head support device for a rotary magnetic head device according to the present invention includes an electro-mechanical transducer, such as the bimorph plate 32, which also displaces the head chip 31 of the rotary magnetic head device substantially in the gap direction. A lead wire 35 for supplying an electrical signal to the electro-mechanical conversion element, and a conductive elastic member disposed between these lead wires and the electro-mechanical conversion element to make an electrical connection by press-contacting each of them. For example, a conductive rubber 36, an insulating member for press-contacting the lead wire to the electro-mechanical conversion element via the conductive member, and a head base made of an elastic material having a U-shaped cross section. In addition, the U of the above head base
Since the insulating member, the lead wire, the conductive member, and the electromechanical conversion element are sandwiched in this order in the letter-shaped gap, assembly is easy, the protection of the electromechanical conversion element is ensured, and The electro-mechanical conversion element can be stably fixed and held, and it can be easily removed, thereby achieving the intended purpose of improving serviceability such as maintenance.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a general rotating magnetic head device, FIG. 2 is a plan view showing recording tracks on a magnetic tape, and FIG. 3 is a perspective view illustrating a conventional head support device. 4 and 5 are perspective views and sectional side views showing other conventional examples, and FIGS. 6 to 9 show an embodiment of a head support device for a rotating magnetic head device according to the present invention. The figure is a perspective view seen from the bottom side, Figure 7 is a side view, Figure 8 is a plan view of the state attached to the rotating disk, Figure 9 is a sectional view taken along the line X-X of Figure 8, and Figure 10 is FIG. 7 is a partially cutaway perspective view showing another embodiment. 30...Head support device, 31...Head chip, 32...Bimorph plate, 3
3...Head base, 33a...Closed end, 33b...Open end, 34...Insulating member, 35... Lead wire, 36...
conductive rubber.

Claims (1)

[Scope of utility model registration request] An electro-mechanical transducer for displacing a head chip of a rotating magnetic head device substantially in the gap direction, a lead wire for supplying an electrical signal to the electro-mechanical transducer, and a connection between these lead wires and the electro-mechanical transducer. an electrically conductive member disposed between the electrically conductive members and electrically connected by press-contacting each other; an insulating member for press-contacting the lead wire to the electro-mechanical conversion element via the conductive member; and a U-shaped head base made of an elastic material, and the insulating member, lead wire, conductive member, and electromechanical conversion element are sandwiched in this order in the U-shaped gap of the head base. A head support device for a rotating magnetic head device, characterized in that a head support device is provided.