JPH0119232Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a support device for a head, and in particular, to form a predetermined recording track on the recording medium by relative movement between the recording medium and the head, or to record information on this recording track. The present invention relates to a head support device in a recording and reproducing apparatus that reproduces information that is being recorded.

In a rotating head type helical scan VTR (video tape recorder), a recording track that is inclined according to the inclination angle of the wound tape with respect to the head drum, the tape running speed, the rotational speed of the rotating head, etc. is usually recorded on the magnetic tape. It is formed. Therefore, when playing back a magnetic tape by running it at a speed different from the speed at which it was recorded, for example when playing back in still, slow motion, double speed, reverse, etc. modes, the scanning trajectory of the head is This causes the head to scan off the predetermined recording track. If the magnetic head scans off the predetermined recording track in this way, guard band noise and crosstalk will occur, which is undesirable. Therefore, in this type of VTR, a tracking correction means is required to ensure that the magnetic head correctly scans the recording track in various modes. As such tracking correction means, there is a magnetic head support device using an electro-mechanical conversion element, for example, a bimorph plate.

FIG. 1 shows the basic structure of the bimorph plate. In FIG. 1, the bimorph plate 1 is
A piezo-ceramic element 4 having electrodes 2 and 3 adhered to both sides by silk printing or the like, and a piezo-ceramic element 7 having electrodes 5 and 6 applied to both sides in the same way. ing. A shim 8 is bonded between the piezo ceramic elements 4 and 7 so that their respective polarization directions are opposite to each other as shown by the arrows in FIG. , 5 are in contact with the shim 8, respectively. The shim 8 is intended to reinforce the bimorph plate 1, and is made of phosphor bronze, titanium alloy, carbon fiber, or the like.

When the bimorph plate 1 is cantilevered as shown in FIG. 2 and a voltage is applied, an electric field is generated in the piezo ceramic element 4 in the direction from the electrode 2 to the electrode 3 (in the opposite direction to the polarization direction). Because it can be applied,
Due to the piezoelectric effect, the ceramic element 4
It deforms in the direction of elongation as shown by the arrow in the figure. Further, since an electric field is applied to the other ceramic element 7 in the direction from the electrode 5 to the electrode 6 (polarization direction), the ceramic element 7 is deformed in the direction of contraction. As a result, the bimorph plate 1 is bent as shown in FIG. 2, and the magnetic head 9 attached to the free end of the bimorph plate 1 via the head attachment member 14 is deflected (displaced). The magnitude of the bias increases or decreases depending on the magnitude of the electric field applied to the ceramic elements 4,7. Note that if the direction of the electric field is reversed, the direction of displacement will also be reversed.

An example of a conventional head support device constructed using the bimorph plate 1 described above is shown in FIG. In FIG. 3, one end of the bimorph plate 1 constituting the first electro-mechanical transducer is connected to a second bimorph plate 1, which is a type of electro-mechanical transducer similar to the bimorph 1, and is made of, for example, a piezo ceramic element. A pair of electricity
It is held between a pair of sub-bimorph plates 10 and 11 that constitute a mechanical transducer. Further, in the sandwiched state, as shown in FIG. 4, it is supported in a cantilever by the holder portion 13 of the rotating drum 12a of the rotating head drum 12. Further, the sub-bimorph plates 10 and 11 are provided with electrodes 10a, 10b and
1a and 11b are respectively applied. The electrodes 10b and 11a of the sub-bimorph plates 10 and 11 are bonded to the electrodes 2 and 6 of the bimorph plate 1 so as to be in contact with each other, respectively.

Further, the polarization directions of the piezo ceramic elements 4, 7 and the sub-bimorph plates 10, 11 in the bimorph plate 1 are in the direction of the arrow shown in FIG. That is, the polarization directions of the piezoceramic elements 4 and 7 are opposite to each other, and the polarization direction of the subbimorph plate 10 is the same as the polarization direction of the piezoceramic element 7. Furthermore, the polarization direction of the sub-bimorph plate 11 is the same as the polarization direction of the piezo ceramic element 4.

On the other hand, a head mounting member 14 is connected to the free end of the bimorph plate 1, and a magnetic head 9 is adhesively fixed to the head mounting member 14. That is, the magnetic head 9 is attached to the bimorph plate 1 via the head attachment member 14, and although not shown, the magnetic head 9 is inserted from the slit 15 of the rotating drum 12a into the rotating drum 12a. It protrudes somewhat outward from the outer circumferential surface.

The operation of the head support device constructed as described above will be explained based on FIGS. 5 and 6.
5 and 6, the electrode 2 of the bimorph plate 1 and the electrode 11b of the sub-bimorph plate 11 are electrically connected by a lead wire 16, and the electrode 6 of the bimorph plate 1 and the electrode 11b of the sub-bimorph plate 10 are electrically connected. The electrode 10a is electrically connected by a lead wire 17. In addition, the electrodes 6 and 1
0a are both grounded via a lead wire 17. Furthermore, a diode is connected between the electrodes 2 and 6 and the shim 8 as shown in FIGS. 5 and 6, so that a variable positive or negative voltage is applied to the electrode 2. ing.

In this state, when a positive voltage is first applied to the electrode 2, the piezo ceramic element 4 of the bimorph plate 1 will be moved in the direction from the electrode 2 to the electrode 3 (in the opposite direction to the polarization direction). As an electric field is applied, the piezo ceramic 4 stretches in the direction indicated by the arrow in FIG. At this time,
Since an electric field is applied to the piezo-ceramic element 7 of the bimorph plate 1 in the direction from the electrode 5 to the electrode 6 (polarization direction), the piezo-ceramic element 7 contracts in the direction shown by the arrow in FIG. .

On the other hand, an electric field is applied to one sub-bimorph plate 10 of the pair of sub-bimorph plates 10 and 11 holding the bimorph plate 1 in the direction from the electrode 10b to the electrode 10a (the opposite direction to the polarization direction). Therefore, the sub-bimorph plate 10 is
Stretch in the direction indicated by the arrow in the figure. Further, since an electric field is applied to the other sub-bimorph plate 11 in a direction (polarization direction) from the electrode 11b toward the electrode 11a, the sub-bimorph plate 11 contracts in the direction shown by the arrow in FIG.

As a result, the actual displacement distance of the free end of the bimorph plate 1 is not only the displacement distance of the free end due to the deflection of the protruding portion of the bimorph plate 1 from the sub-bimorph plates 10 and 11, but also the actual displacement distance of the free end of the sub-bimorph plate 1.
This is the sum of the displacement distance of the free end based on the expansion and contraction of 0 and 11. Therefore, the above bimorph plate 1
As described above, when the bimorph plate 1 is held between a pair of sub-bimorph plates, even if a relatively small voltage is applied, the free end of the bimorph plate 1 and the magnetic head 9 will not be displaced. The distance can be made sufficiently large.

However, in such a conventional head support device, a bimorph plate 1 as a first electro-mechanical conversion element and a pair of sub-bimorph plates 10, 1 as a second pair of electro-mechanical conversion elements are used.
When an electric field is applied to the bimorph body 26, which is an electro-mechanical transducer body composed of 1 and 1, the portion in the holder portion 13 shown in FIG. 3 also expands and contracts. Due to the expansion and contraction, the portion of the holder portion 13 in the bimorph body 26 is deformed.

On the other hand, since the holder portion of the rotating drum 12a rotates at high speed, centrifugal force is constantly acting on the bimorph body 26. As a result, when the holder portion is deformed as described above, the bimorph body 26 and the magnetic head 9 attached to the free end side of the bimorph plate 1 slip rearward in the direction of head rotation.

By the way, the bimorph body 26 is fastened and fixed to the holder part 13 by a fixing screw, but in order to prevent the bimorph body 26 from cracking, the tightening force of the fixing screw cannot be made large enough to prevent slipping. .

That is, in the conventional head support device,
There is a disadvantage that the magnetic head 9 slips backward in the direction of rotation of the head.

The present invention eliminates such conventional drawbacks, and mechanically prevents the first electro-mechanical transducer and the second pair of electro-mechanical transducers from slipping backward in the rotational direction of the head. The object of the present invention is to provide a head support device in a recording/reproducing apparatus that can perform the following functions.

That is, the feature of the head support device in the recording/reproducing apparatus according to the present invention is that a predetermined recording track is formed on the recording medium by relative movement between the recording medium and the head, or recording is performed on this recording track. A recording/reproducing device configured to reproduce information includes: a first electro-mechanical transducer element to which a free end side is connected to a head mounting member to which the head is attached; and one end portion of the first electro-mechanical transducer element. and a second pair of electro-mechanical transducers that sandwich the electro-mechanical transducers, and the electro-mechanical transducer body includes a second pair of electro-mechanical transducers that sandwich the second pair of electro-mechanical transducers.
The mechanical conversion element is tightened and fixed to the holder part with a single fixing screw and is mounted in a cantilevered manner, and the electro-mechanical conversion element body is supported in contact with a fixed shaft installed at a rear position in the rotation direction. This is how it was done.

Below, preferred embodiments of the present invention will be described.
This will be explained with reference to the drawings. The structure and operation of the bimorph body 26 are described in the first section above.
It is the same as that shown in the figures through FIG. 6, and detailed explanation will be omitted.

First, FIG. 7 shows the head support device 2 of this embodiment.
FIG. This head support device 25
is a pair of bimorph bodies 2 having a planar triangular shape.
6, 26, each of the above bimorph bodies 26, 2
A pair of magnetic tapes 6 are supported by a holder portion 13 in a cantilever manner so as to face each other parallel to each other in the width direction of the magnetic tape T. Further, each of the bimorph bodies 26, 26 is fastened and fixed to the holder part 13 by a single fixing screw 18 so as not to be displaced from each other in the direction of rotation of the head. Further, the magnetic head 9 is adhesively fixed via a head mounting member 14 having a U-shaped cross section and connected to the free end side of each of the bimorph plates 26, 26. That is, the magnetic head 9 is adhesively fixed to a head mounting member 14 connected to the free end sides of a pair of bimorph plates 1, 1 constituting the bimorph body 26. The head 9 is moved in the width direction of the magnetic tape T by the pair of bimorph bodies 26, 26, but the reason why the pair of bimorph bodies 26, 26 is used is to move the head 9 in the width direction of the magnetic tape T On the other hand, the purpose is to move the magnetic head 9 more parallelly, and it is obvious that one bimorph body 26 may be used to move the magnetic head 9.

Furthermore, the pair of bimorph bodies 26, 26
is a fixed shaft 2 that is located at the rear in the direction of rotation of the head and is installed on the outer edge of the holder near the magnetic head 9.
It is abutted and supported by 2. The fixed shaft 22 has a cylindrical shape, and is fixed to a mounting piece 23 with an adhesive or the like for mounting the fixed shaft 22 upright. Further, the mounting piece 23 has a fixing screw 19
It is tightened and fixed to the rotating head drum 12 by means of the following. Here, the fixed shaft 22 and the mounting piece 2
Since the abutting support member 24 consisting of the two members 3 and 3 is fastened and fixed to the rotary head drum 12 by the fixing screw 19, the position can be corrected to a certain extent and a good abutting and supporting state can be obtained.

As mentioned above, by providing the abutting support member 24 at the rear position in the direction of rotation of the head, that is,
By installing the fixed shaft 22 at a rear position in the head rotation direction and supporting the bimorph bodies 26, 26 in contact with each other, even if deformation occurs in the holder portion 13 of the bimorph bodies 26, 26, for example, the bimorph bodies 26 , 26 can be prevented from slipping backward in the direction of rotation of the head.

Further, the fixed shaft 22 of the abutting support member 24 is
The bimorph bodies 26, 26 and the holder part 1
3 and is bonded with an adhesive or the like. Furthermore, it is preferable to apply an adhesive or the like over the entire surface of the bimorph bodies 26, 26 and the side surfaces of the holder part 13 in order to more firmly fix the bimorph bodies 26, 26 to the holder part 13.

Although the fixed shaft 22, which is the main part of this embodiment, has a circular cross-sectional shape, it is not necessarily limited to a circle, and the fixed shaft 22 can have a cross-sectional shape such as an ellipse or a polygon. is possible. In this case as well, the other parts may be constructed in the same manner as in this embodiment, and are not shown in the drawings and their explanation will be omitted. Furthermore, the effects are also similar to those of this embodiment.

As is clear from the above description, according to the head support device according to the present invention, by supporting the first and second electro-mechanical transducers in contact with the fixed shaft, the electro-mechanical transducers are It is possible to prevent the head from slipping backward in the direction of rotation.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the structure of a bimorph plate, FIG. 2 is a side view of a main part of a head support device using this bimorph board, and FIG. 3 is a side view of a main part of a head support device using a bimorph body. Fig. 4 is a partially cutaway plan view of the main part of the head support device assembled to the rotating head drum, Figs. 5 and 6 are side views showing the operation of the bimorph body, and Fig. 7 is the invention of the present invention. FIG. 8 is a perspective view showing this embodiment, and FIG. 8 is a plan view showing this embodiment. DESCRIPTION OF SYMBOLS 1... Bimorph plate as a first electro-mechanical conversion element, 9... Magnetic head, 10, 11... Bimorph plate as a second electro-mechanical conversion element, 14...
Head mounting member, 22...fixed shaft, 23...mounting piece,
24...Abutment support member, 25...Head support device.

Claims (1)

[Claims for Utility Model Registration] (1) Forming a predetermined recording track on the recording medium by relative movement between the recording medium and the head, or reproducing information recorded on this recording track. In the recording and reproducing apparatus, the head mounting member to which the head is attached includes a first electro-mechanical transducer connected to the free end side, and a second electro-mechanical transducer that clamps one end of the first electro-mechanical transducer. It has an electro-mechanical conversion element body consisting of a pair of electro-mechanical conversion elements, and this electro-mechanical conversion element body has the second pair of electro-mechanical conversion elements fixed to the holder part with one fixing screw. A head support device for a recording/reproducing device, wherein the electro-mechanical transducer element body is mounted in a cantilevered manner by being tightened and fixed, and is supported in contact with a fixed shaft installed at a rear position in the rotation direction. (2) The electro-mechanical transducer body has a pair disposed parallel to each other, and the head is a first one of the pair.
A head support device for a recording/reproducing apparatus according to claim 1, which is attached to a head attachment member connected to a free end side of an electro-mechanical transducer.