JP2718283B2 - Magnetic recording / reproducing 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 magnetic recording / reproducing apparatus having a rotating head assembly, such as a video tape recorder or a digital video tape recorder, and more particularly, to a tangential direction of a rotating circumference of a rotating magnetic head. against at an angle and recorded (hereinafter, referred to as "inclined azimuth recording") Ru <br/> relates to a magnetic recording and reproducing equipment that make it possible.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view showing a main part of a conventional magnetic recording / reproducing apparatus, and FIG. 7 is a view taken along a line VII-VII in FIG. 6 and 7, 1 is a fixed drum, 2 is a bearing mounted on the fixed drum 1, 3 is a rotating shaft supported by the bearing 2 and rotated, 4 is a pedestal fitted to one end of the rotating shaft 3, 5 is a rotary drum attached to the pedestal 4 with screws 6;
7 is a magnetic head driving device mounted on the rotating drum 5 with screws 8, 9 is a lower transformer mounted on the fixed drum 1,
Reference numeral 10 denotes an upper transformer mounted on the base 4, reference numeral 11 denotes a wiring board mounted on the rotary drum 5, and reference numeral 12 denotes a contact for supplying a control current to the magnetic head driving device 7.

Reference numeral 13 denotes a pedestal 4 so as to slide on the contact 12.
Are connected to the magnetic head driving device 7 via the connecting portion 15 and the wiring board 11 from the rotating electrode 13, and 14a is a bobbin 30.
A flexible board or the like is used as a lead wire from the coil 31 wound around. 16 is a magnetic head driving unit 7
The magnetic head is electrically connected to the upper transformer 10 via the connection portion 17, the wiring board 11, and the connection portion 15.

Reference numeral 18 denotes a recess provided in a part of the rotary drum 5 for accommodating the magnetic head driving device 7, and is formed larger than the magnetic head driving unit 7 so that the position of the magnetic head 16 can be adjusted. . 19 is a position adjusting hole for adjusting the position of the magnetic head 16, and 20 is a magnetic tape that slides on the magnetic head 16.

FIGS. 8, 9 and 10 show the magnetic head driving device 7 in more detail.
Is a first yoke made of a magnetic material, 22 is a first columnar permanent magnet fixed to the first yoke 21, and 23 is a first yoke 21 A second yoke 24 made of a magnetic material is attached to the second yoke 23, and a third yoke 24 made of a magnetic material is attached to the second yoke 23.

Reference numeral 25 denotes a second columnar column fixed to the third yoke 24 with the same magnetic pole facing the first permanent magnet 22.
Is a ball piece made of a magnetic material, which is located between the second permanent magnet 25 and the first permanent magnet 22 and is fixed to one of them.

[0007] 27 is a leaf spring made of a non-magnetic material of the thin plate, one end is sandwiched between the first yoke 21 to second yoke 23, and the extending portion 27a is the first yoke 21 and window 21a, which is kicked set in the second yoke 23, 23
and a magnetic head 16 is attached to the end thereof. 28 is a leaf spring made of a non-magnetic material sheet, and both ends are held between the second yoke 23 third yoke 24.

Reference numeral 29 denotes a fixing member held by each of the leaf springs 27 and 28, and 30 denotes a bobbin, the inner periphery of which is a first permanent magnet 22, a second permanent magnet 25, and a pole piece 26.
Is fixed to the fixing member 29 with an adhesive 32 at a position having a gap with the outer periphery of the fixing member 29. Reference numeral 31 denotes a coil made of an electric wire having a coating material wound around the bobbin 30, and is provided between the coil 31 and the convex portion 23 b of the second yoke 23.
An annular gap G is provided over the entire circumference.

Next, the operation will be described with reference to FIG. First, the first permanent magnet 22 generates a magnetic flux D in a closed magnetic path formed by the pole piece 26, the second yoke 23, and the first yoke 21. Similarly, the second permanent magnet 25
Generates a magnetic flux E in the closed magnetic path formed by the pole piece 26, the second yoke 23, and the third yoke 24 in a direction opposite to the magnetic flux D.

[0010] The magnetic flux D and flux E are both annular gap F, the lateral cutting a G in the same direction, the first permanent magnet 2
The total magnetic flux of the second and second permanent magnets 25 crosses the coil 31. In this state, the coil 31 is supplied from a driving power source (not shown) to the contact 12, the electrode 13, the connection portions 15, 14, and
When a drive current is passed through the coil 31, the coil 31, the bobbin 30, and the magnetic head 16 integrally move linearly vertically in parallel.

[0011]

The conventional magnetic head driving device is configured as described above, and the rotating head is
It can only be moved up and down in parallel with its rotation axis.When playing back a magnetic tape recorded with an inclined azimuth, if the azimuth angle between recording and playback is shifted, azimuth loss and An optimum reproduced signal could not be obtained due to crosstalk or the like.

Further, in the conventional magnetic recording and reproducing apparatus, the mounting accuracy, time of recording using a fixed head, because of the use of special playback and playback only the driving head, the head number of <br/> increase Univ etc. Contact and increased electrical components such as an amplifier for each head, an increase of the head portion occupied area of the drum, high cost, there is a problem such as difficulty in downsizing due to increased parts.

Further, considering the example of a VTR, a head having a fixed azimuth angle uses a head configuration different from that in normal reproduction when performing special reproduction such as still image (still image) reproduction or slow reproduction. The synchronization of the reproduction signal differs for each vertical scan (one field). For this reason, synchronization is deviated for each field, and play is produced on the screen. To correct this, there is an inconvenience that the user has to adjust the still picture vertical synchronization variable volume attached to the VTR.

Hereinafter, these causes will be described with reference to FIGS. In FIG. 11, 50 is a drum for rotating the head, 51 is the rotation direction of the rotary drum 50, 52 is a standard mode head, 53 is a triple mode head, and the subscripts a and b are right azimuth, respectively. Shows a head with a left azimuth. Hereinafter, the left azimuth head 52b for the standard mode and the right azimuth head 53a for the triple mode are collectively referred to as a double azimuth head 54.

At the time of normal recording / reproducing, in the case of the standard mode, the head width 48 which is arranged to be opposed at 180 degrees.
Micron heads 52a and 52b are used. Similarly,
In the case of the triple mode, the head 5 having a head width of 26 microns is used.
3a and 53b are used. The head width of these heads is
It is determined in consideration of the head configuration and the like during special reproduction.

FIG. 11A shows a simplified diagram of a recording tape pattern and a head locus 56 when reproducing a still image. At the time of reproducing a still image, the magnetic tape 55 is stopped. As can be seen from the tape pattern and the head locus 56, most of the heads pass through the left azimuth recording track, so that it is advantageous to use the left azimuth head when reproducing a still image.

However, during normal reproduction, the heads having left and right azimuths are alternately used. Therefore, in order to always obtain a reproduction signal using the same azimuth head, a standard mode head is used. A left azimuth head 52b,
A left azimuth head 53b for the triple mode is used. Thereby, one video track can be reproduced by a head having the same azimuth as the azimuth at the time of recording, and a still image can be obtained.

As described above, although one track is not exactly faced at 180 degrees, a still picture can be reproduced by reproducing one track using the same azimuth head, but there is a deviation in the period of the synchronization signal. Occurs. This will be described below with reference to FIG.

The head switch signal (FIG. 12A) is
At the time of normal reproduction, this signal is used for switching heads having two different azimuths facing each other, and is synchronized with a vertical synchronizing signal (FIG. 12B) of a TV signal. The head is switched at the edge of the head switch signal, and after switching the head, 5 to 8 horizontal synchronization signal times (about 413 micro time)
It is adjusted so that the vertical synchronization signal comes later.

For example, in FIG. 12, the head switch signal uses a right azimuth head in portions A and C in an H level section, and uses a left azimuth head in portion B in an L level section.

During reproduction of a still image, as described above, the same azimuth head is used in each of the sections where the head switch signal is at the H level and the L level, but the still image is reproduced using only the left azimuth head. Normally, in the section where the right azimuth head is used at the time of reproduction (A and C in FIG. 12 (a)), the position of the synchronization signal is shown in FIG.
It shifts like a vertical synchronization signal at the time of the still of 2 (c), and therefore, the vertical synchronization (one field) section expands and contracts every cycle.

In order to correct this expansion / contraction, a mono-multi is run in synchronization with the rise of the head switch signal, and the vertical synchronizing signal is changed using the mono-multi output signal (FIG. 12 (d)).

The adjustment of the width of the mono-multi signal is called a still image vertical synchronization adjustment, and is a task that requires only adjustment by the user himself due to the relationship with a monitor that displays images.

In terms of structure, the conventional magnetic head drive unit has a problem that the number of parts is large, the assembly process is extremely difficult, it is very difficult to reduce the size and weight, and the cost is high. was there.

The present invention has been made in order to solve the above-mentioned problems .
A head drive device that can change the azimuth angle of the mounted magnetic head in addition to moving it in the axial direction
It is an object of the present invention to obtain a magnetic recording / reproducing apparatus provided .

[0026]

According to the present invention, there is provided a magnetic recording reproducing apparatus comprising:
The raw device is mounted on a rotating drum around which a magnetic tape is wound.
A magnetic head that scans a magnetic tape and this magnetic head
A magnetic head that can move in the axial direction of the rotating drum
A magnetic recording / reproducing apparatus having a
The magnetic head driving device is made of a non-magnetic material and has a housing portion.
A yoke to be formed, and a yoke provided in the accommodation portion of the yoke.
And one end is held by the yoke, and the other end is
A flat plate that extends outside the housing and fixes the magnetic head
An elastic member and an upper surface of the elastic member
The elastic member is spaced apart in a direction perpendicular to the extending direction of the elastic member.
And each axis is substantially perpendicular to one surface of the elastic member.
Pair of permanent magnets or coils,
Facing the permanent magnet or coil, respectively, and
A pair of coils or permanent magnets provided on the yoke
Provided in each of the pair of coils in the same or opposite direction.
The azimuth angle of the magnetic head by supplying
Characterized in that so as to vary.

[0027]

According to the present invention, the azimuth angle can be changed by changing the direction or the DC component of the current supplied to the two electromagnetic driving units of the magnetic head driving device .

[0028]

BRIEF DESCRIPTION based on an embodiment of the present invention with reference to the accompanying drawings. FIG. 1 is a diagram showing the configuration of an embodiment of a magnetic head driving device according to the present invention . FIG. 1A is a longitudinal sectional view of a magnetic head driving device according to the present embodiment, and FIG. Figure 1
1A is a plan view taken along line bb of FIG. 1, and FIG.
2 (a) and 2 (b) are cross-sectional views taken along line cc of FIG. 2 for explaining the operation of the present embodiment.

In FIG. 1, reference numeral 33 denotes a first yoke made of a non-magnetic material, and reference numeral 34 denotes a second yoke made of a non-magnetic material.
Then, by being connected to the first yoke, the internal space is
Form a receiving section that is between. 35 is made of non-magnetic material
A flat elastic member , one end of which is sandwiched between the first yoke 33 and the second yoke 34 and the other end is provided in the first yoke 33 and the second yoke 34 in the accommodation portion. and has a window 33 c, which extend into the housing outer through 34a, on its distal end, the magnetic head 16 is mounted.

[0030] 36a, 36b are cylindrical pair of first permanent magnet fixed to the first yoke 33, 37a, 37b
Denotes a pair of second permanent magnets, and the first permanent magnets 36a, 36a
The magnetic pole 6b is fixed to the second yoke 34 so as to face the same magnetic pole. 38a, 38b in the hollow cylindrical coil secured to the elastic member 35, on one surface of the elastic member, the elastic member
Are provided in a direction perpendicular to the extending direction of the
Each axis is set to be almost perpendicular to one surface of the elastic member
At the same time, the first permanent magnets 36a and 36b and the second permanent magnets 37a and 37b are located on the axis and opposed to each other.
As shown in FIG.
a, 37a and 38a constitute one electromagnetic drive unit, and 36
b, 37b, constitute another electromagnetic drive unit in 38b.

Next, the operation will be described. FIG. 2 (a)
In the hollow cylindrical coil 38a, a 38b, as shown in FIG.
When a current in the same direction is supplied to the H side, a clockwise magnetic field J1 is generated on the H side, and a counterclockwise magnetic field J2 is generated on the I side. The magnetic fields J1, J2 and the first permanent magnets 36a, 36
6b, an attractive force acts between the first permanent magnet and the hollow cylindrical coil on the upper side, and a repulsive force acts between the second permanent magnets 37a, 37b and the hollow cylindrical coil on the lower side. Works. Due to the attraction and repulsion, the elastic member 3
5 moves in the upward direction (L direction), and the magnetic head 16 attached to this extending portion also moves in the L direction , that is, the axial direction of the rotating drum.
Move in the direction .

This moving direction is determined by the hollow cylindrical coils 38a.
It can be changed by changing the direction of the current flowing through 38b, and the amount of movement can be adjusted by adjusting the amount of current.

FIG. 2B is a diagram showing a driving state when the azimuth is changed. The hollow cylindrical coils 38a, 38b
, As in each figure, the case of flowing the opposite direction of the current. In this case, a clockwise magnetic field J1 is generated on the H side, and I
On the side, a magnetic field J2 is generated in a counterclockwise direction.
Unlike the case of (a), the direction of the magnetic field generated by the hollow cylindrical coil 38a on the permanent magnet 36a, 37a side is opposite. Therefore, on the hollow cylindrical coil 38a side, the arrow M
At the hollow cylindrical coil 38b side, an attractive force and a repulsive force acting in the direction of arrow L act, and the elastic member 35 is bent in the counterclockwise direction.
The azimuth of the magnetic head 16 attached to the existing portion changes.

The direction and amount of changing the azimuth are determined by the first permanent magnets 36a and 36b and the second permanent magnet 3a.
The adjustment can be made by changing the directions of the magnetic poles of the coils 7a and 37b or by changing the DC component included in the drive current flowing through the hollow cylindrical coils 38a and 38b.

FIGS. 3 to 5 are longitudinal sectional views of another embodiment of the present invention, each showing the same section as that of FIG. 1 (a).
FIG. 3 is a configuration diagram when only one permanent magnet is used. The drive sensitivity of the magnetic head is slightly reduced,
Dimensions can be reduced.

FIG. 4 is fixed a cylindrical permanent magnet 37 to the elastic member 35, the permanent provided magnetic coils 40 on the yoke side
It is arranged so as to face the magnet 37 .

FIG. 5 shows an example using two elastic members.
An elastic member 35 to which the magnetic coil 43 is fixed;
And a connecting member 44 for connecting the two elastic members 35 and 45 to each other. According to this configuration, disturbance in the projecting direction of the magnetic head 16 can be absorbed.

[0038]

As is evident from the foregoing description, according to the present invention, not only move the rotary magnetic head in the axial direction of the rotary drum,
Since the angle of the rotating magnetic head can be changed with respect to the tangential direction of the rotating circumference, it is possible to reproduce a high-quality video signal with less azimuth loss. In the case of reproducing a video track of the same azimuth in reproduction of a still image or the like, a head which is exactly 180 degrees opposite can be used, so that the period of the vertical synchronizing signal in the TV signal is constant. In other words, the vertical synchronization adjustment of the still image, which has conventionally been performed by the user, is not required.

Further, in the structure surface, since the structure of the magnetic head driving device is simplified from the prior art, it is possible to reduce the number of components, since the assembly process can be simplified, it is possible to lower the cost The size and weight can be reduced.

[Brief description of the drawings]

An embodiment of a magnetic head driving device definitive to the present invention; FIG
It is a longitudinal section showing an example .

FIG. 2 is a diagram for explaining the operation of the present embodiment.

FIG. 3 is a longitudinal sectional view of another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of another embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of still another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a main part of a conventional magnetic recording / reproducing apparatus.

7 is a sectional view taken along the line VII-VII of FIG.

FIG. 8 is an enlarged plan view of a main part showing details of a conventional magnetic head driving unit.

FIG. 9 is a vertical sectional view taken along line IX-IX in FIG. 8;

FIG. 10 is a side view of FIG. 9;

FIG. 11 is a diagram showing an arrangement of a tape pattern and a head.

FIG. 12 is a diagram showing head switching and the timing of a vertical synchronization signal.

[Explanation of symbols]

 7 Magnetic head driving device 16 Magnetic head 33 First yoke 34 Second yoke 35 Elastic member 36a, 36b, 37a, 37b Permanent magnet 38a, 38b Cylindrical coil

Claims (1)

(57) [Claims] 1. A rotary drum on which a magnetic tape is wound,
A magnetic head that scans the magnetic tape, and a magnetic head
Magnetic head that can be moved in the axial direction of the rotating drum.
Magnetic recording / reproducing apparatus having a magnetic head driving device
Therefore, the magnetic head driving device is made of a non-magnetic material,
A yoke for forming a housing, and
One end is held by the yoke, and the other end is
A flat plate that extends outside the housing and fixes the magnetic head
Elastic member and one surface of the elastic member in the housing portion
At a distance in the direction perpendicular to the direction in which the elastic member extends.
Provided, and their respective axes are substantially orthogonal to one surface of the elastic member.
A pair of permanent magnets or coils adapted to
Opposed to a pair of permanent magnets or coils, respectively, and their respective axes
A pair of coils or permanent magnets provided on the yoke above
Stone and the same or opposite direction for each of the pair of coils
Azimuth of the magnetic head
Magnetic recording characterized by changing the angle of the magnetic field
Playback device .