JPH0461015A - Rotary magnetic head assembly - Google Patents

Abstract

PURPOSE:To obtain excellent linearity for a recording track at the time of recording by arranging a magnetic head on near the window part of a yoke and providing a member for magnetic head fixing securing the magnetic head after deformation at the time of recording. CONSTITUTION:A member 50 for magnetic head fixing is attached to near the window part of a yoke 24. After a magnetic head 16 deforms the member 50 for magnetic head fixing equipped near the window part of the yoke 24 projected outside up and down by constant amount, a bobbin 30 is moved up and down by flowing constant current in the bobbin 30. Thus, the magnetic head 16 is fixed to the yoke 24 by pressed through the member 50 for magnetic head fixing, and good linearity for recording track can be obtained without influencing the magnetic head 16 by the force from the magnetic tape and disturbance from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a rotating magnetic head assembly mounted on a magnetic recording/reproducing apparatus such as a VTR or a DAT.

[Conventional technology]

FIG. 3 is a sectional view showing the main parts of a rotating drum device including a conventional magnetic head drive device, and FIG.
- It is a view taken along the line IV. In FIGS. 3 and 4, 1 is a lower drum, 2 is a bearing attached to the lower drum 1, 3 is a rotating shaft supported by the bearing 2 and rotates, and 4 is fitted to one end of the rotating shaft 3. 5 is an upper drum attached to the pedestal 4 using screws 6; 7 is an upper drum attached to the upper drum 5 with screws 8;
9 is a lower transformer attached to the lower drum 1, 10 is an upper transformer attached to the pedestal 4, 11 is a wiring board attached to the upper drum 5, and 12 is a magnetic head. A non-rotating contact 13 is a contact 1 for supplying a control current to the drive device 7
This is a rotating electrode provided on a part of the pedestal 4 so as to be in sliding contact with the pedestal 2.

Further, reference numeral 14 denotes a connecting portion for electrically connecting the electrode 13 to the magnetic head driving device 7 via the connecting portion 15 and the wiring board 11;
Reference numeral 16 denotes a magnetic head attached to the magnetic head drive device 7, which includes a connecting portion 17° and a wiring board 11. It is electrically connected to the upper transformer 10 via the connecting portion 15 . Reference numeral 18 denotes a recess provided in a part of the upper drum 5 to house the magnetic head drive device 7. The recess 18 is one size thicker than the magnetic head drive device 7 (not formed) so that the position of the magnetic head 16 can be adjusted. 19 is a position adjustment hole for adjusting the position of the magnetic head 16, and 20 is a magnetic tape that comes into sliding contact with the magnetic head 16.

FIG. 5 shows the details of the magnetic head drive device at V- in FIG. 3.
6 is a sectional view of FIG. 5, and FIG. 7 is a side view of FIG. 5.

In the figure, 21 is a first yoke made of magnetic material, 22
2 is a columnar first permanent magnet fixed to the first yoke 21;
3 has a convex portion 23a on a part of the inner circumference, and the first yoke 2
a second yoke made of magnetic material attached to 1; 24;
25 is a column-shaped second permanent magnet fixed to the third yoke 24 with the same magnetic pole facing the first permanent magnet 22; 26 is a third yoke made of a magnetic material attached to the second yoke 23; A pole piece 27 is located between the second yoke 24 and the second yoke 23 and is made of a thin plate of non-magnetic material and is fixed to one of the two permanent magnets 25 and 22. 27a is an extension of the leaf spring 27, and the window 24 provided in the third yoke 24 and the second yoke 23
a, 23a and protrudes outward, and a magnetic head 16 is attached to its tip.

Further, 28 is a plate spring made of a thin non-magnetic material held between the first yoke 21 and the second yoke 23, and 29 is the plate spring 2.
The fixing member 30 holding magnets 7 and 28, respectively, is in a position where its inner periphery has a gap between the outer peripheries of the first and second permanent magnets 22 and 25 and the pole piece 26, and is bonded to the fixing member 29. The bobbin 31, which is fixed using the material 32, is in a position where there is a gap over the entire circumference between the bobbin 31 and the convex portion 23a of the second yoke 23.
It is a coil consisting of an electric wire with a covering material wound around 0.

Next, the operation will be explained.

The first permanent magnet 22 is a pole piece 26. Second yoke 23
and the first yoke 21 to generate a magnetic flux. Similarly, the second permanent magnet 25 is the pole piece 26
．． A closed magnetic path formed by the second yoke 23 and the third yoke 24 generates a magnetic flux E in the opposite direction to the above magnetic flux, and both the magnetic flux and the magnetic flux E cross the annular gaps F and G in the same direction.

The total magnetic flux of the first permanent magnet 22 and the second permanent magnet 25 crosses the coil 31 . Coil 31 in the above condition
from contactor 12 to ttfi13. When a current is passed through the continuation portion 15.14, the coil 3I, bobbin 30, and magnetic head 16 move vertically and linearly in parallel, so the magnetic head 16 is displaced in the width direction of the magnetic tape 20, and the magnetic head 16 is displaced in the width direction of the magnetic tape 20. It is designed to trace the recorded traces with high precision.

The magnetic head 16 also has a coil 31 wound around a bobbin.
By applying a constant current to the bobbin, the bobbin can be stopped and fixed in a fixed position.

However, it has been found that when fixing the magnetic head using this conventional tM1 method, the fixing force is small and the magnetic head vibrates up and down due to the force received from the magnetic tape, which affects the linearity of the recording track.

[Problem to be solved by the invention]

Conventional magnetic head drive devices are configured as described above, and in order to perform recording and reproduction using the same head, it is necessary to fix the magnetic head at a fixed position during recording, but conventional magnetic head drives using only electrical means In fixed position,
Since the magnetic head vibrates vertically together with the bobbin due to the reaction force when the magnetic head enters the magnetic tape, there have been problems such as poor linearity of recording tracks and deterioration of image quality.

This invention was made to solve the above-mentioned problems, and allows the magnetic head to be fixed constant without vertically vibrating due to reaction force or disturbance when entering the magnetic tape. It is an object of the present invention to obtain a rotating magnetic head assembly equipped with a magnetic head drive device that can sometimes obtain excellent linearity of recording tracks.

[Means to solve the problem]

The rotary magnetic head assembly according to the present invention includes a first magnetic head in a yoke made of a magnetic material. A second permanent magnet is fixed by sandwiching a pole piece made of a magnetic material between both permanent magnets, and is moved in the vertical direction within the yoke to a position where there is a gap between the two permanent magnets and the outer periphery of the pole piece. In a magnetic head drive device comprising a flexible bobbin, and a magnetic head attached to the bobbin via a leaf spring and its extension so as to be located outside the window of the yoke, A magnetic head fixing member is attached.

[Effect]

The magnetic head driving device in the rotating magnetic head assembly of the present invention deforms the magnetic head fixing member provided near the window of the yoke from which the magnetic head projects outward by a certain amount in the vertical direction during recording, and then By applying a constant current to the bobbin and moving the bobbin in the vertical direction, the magnetic head is pressed and fixed to the yoke via the magnetic head fixing member, and is able to withstand the force and disturbance received from the magnetic tape. Excellent recording track linearity can be obtained without affecting the magnetic head.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of the main parts of a magnetic head driving device of a rotating magnetic head assembly according to an embodiment of the present invention. In the figure, 21 to 32 are exactly the same as the conventional device. Reference numeral 50 denotes a magnetic head fixing member attached near the window of the yoke. This embodiment is an example in which a magnetic head fixing member 50 is attached to the upper surface of the extension portion 27a of the leaf spring 27 to which the magnetic henode 16 is fixed, and a bimorph member is used as the fixing member. .

FIG. 2 is an enlarged view of the mounting portion of the magnetic head fixing member of the magnetic head drive device according to the present invention.

Next, the operation will be explained.

1 and 2, during recording, a current is applied to the magnetic head fixing member 50 to deform it so that it protrudes upward, that is, toward the lower end of the convex portion 23a of the yoke 23. The magnetic head 16 is fixed by applying an electric current and moving upward the magnetic head 16 fixed to the leaf spring 27 and its extension 27a, which are integrated with the bobbin 3o by the adhesive 32. The convex portion 23a of the yoke 23 is inserted through the member 50.
Press it against the bottom edge of the

Therefore, the magnetic head can be fixed in the tape width direction against reaction forces and disturbances received from the magnetic tape, and excellent linearity of recording tracks can be obtained.

In the above embodiment, the magnetic head fixing member 50 is attached to the extending portion 2 of the leaf spring 27 to which the magnetic head 16 is fixedly attached.
Although an example is shown in which it is attached to the upper surface of the leaf spring 7a, the same operation can be expected even when it is attached to the lower surface of the extension portion 27a of the leaf spring 27, or conversely, when it is attached to the yoke side.

Further, in the above embodiment, an example is shown in which a bimorph member is used as the magnetic head fixing member, but any material that deforms itself by supplying energy, such as a shape memory alloy, may be used. The same effect as in the example can be expected.

〔Effect of the invention〕

As described above, according to the rotating magnetic head assembly according to the present invention, the magnetic head, which is attached via the leaf spring and its extension portion to the bobbin that can reciprocate in the vertical direction, that is, in the width direction of the magnetic tape, can be moved in the same manner. The magnetic head fixing member attached to the extending portion is deformed toward the lower end of the convex portion of the yoke, and then the bobbin is moved upward to fix the magnetic head in the width direction of the tape. Therefore, the magnetic head can be fixed in the tape width direction against reaction forces and disturbances received from the magnetic tape, and excellent linearity of recording tracks can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a magnetic head driving device of a rotating magnetic head assembly according to an embodiment of the present invention. FIG. 2 is an enlarged view of the mounting portion of the magnetic head fixing member of the magnetic head drive device according to the present invention. Figure 3 shows
FIG. 4 is a cross-sectional view showing the main parts of a rotating drum device including a conventional magnetic head drive device, FIG. 4 is a view taken along the line IV-IV in FIG. 3, and FIG. ■−
6 is a sectional view of FIG. 5, and FIG. 7 is a side view of FIG. 5. In the figure, 1 is the lower drum, 2 is the bearing, 3 is the rotating shaft, and 4
is a pedestal, 5 is an upper drum, 6 is a screw, 7 is a magnetic head drive device, 8 is a screw, 9 is a lower transformer, 10 is an upper transformer,
11 is a wiring board, 12 is a contact, 13 is an electrode, 14 is a connecting portion, 16 is a magnetic head, 17 is a connecting portion, 18 is a recess, 1
9 is a position adjustment hole, 20 is a magnetic tape, 21 is a first yoke, 22 is a first permanent magnet, 23 is a second yoke, 23a is a convex portion, 24 is a third yoke, 24a is a window, and 25 is a plate Spring, 27a is a leaf spring extension part, 28 is a leaf spring, 29 is a fixing member, 30 is a bobbin, 31 is a coil, 32 is an adhesive, 5
0 is a magnetic throat fixing member. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A fixed cylinder that guides a magnetic tape to an outer circumferential surface, and a rotary cylinder that is rotatably supported via a rotating shaft located in the center of the fixed cylinder and that supports a magnetic head that records and reproduces information on the magnetic tape. a yoke made of a magnetic material; a first permanent magnet and a second permanent magnet fixed in the yoke; a pole piece made of a magnetic material sandwiched between both the permanent magnets; a bobbin disposed at a position with a gap between the permanent magnets and the outer periphery of the pole piece and capable of vertically moving only in the axial direction; In a rotating magnetic head assembly of a magnetic recording/reproducing device, the rotating magnetic head assembly is equipped with a magnetic head driving device comprising a magnetic head mounted so as to be located at the position of the yoke. 1. A rotating magnetic head assembly comprising a magnetic head fixing member that fixes the magnetic head by deforming at times.