JPS6025723Y2 - magnetic head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head device which has been improved to more accurately perform head tracking on a large number of recording tracks formed at high density in the tape width direction.

For example, it has been considered to use an endless tape device as a means for magnetically recording and reproducing video signals using a head mechanism whose position is fixed.

FIG. 1 shows such an endless tape device, in which an endless tape 11 is stored by being wound around the outer circumference of a fixed annular reel 12.
A tape drawer window 13 is formed to communicate between the inside and outside of the window.
The inner periphery of the wound tape 11 is drawn out to the inner periphery of the reel 12 through this window 13.

The tape 11 pulled out from this window 13 is guided to the head mechanism 14 section, and is pulled out and run by a tape drive mechanism consisting of a capstan 15 and a pinch roller 16 by rotating the capstan 15 as shown by the arrow. It is something that

In this case, guide poles 1 are placed on both sides of the head mechanism 14.
7a and 17b are provided, and the tape 11 to be pulled out is
It guides the tape guide 18 of the head mechanism 14 so that it runs in sliding contact with the tape guide 18, and the guide pole 11a,
The height position (width direction position) of the running tape 11 is set by a collar provided on the tape 17b.

Here, the head mechanism 14 includes a box-shaped tape guide 18 having a curved surface along the running direction of the running tape 11, and a through hole is formed on the tape sliding surface of the tape guide 18. The tip portion of the magnetic head 19 protrudes from the through hole and is configured to come into contact with the magnetic surface of the running tape 11.

In this case, the magnetic head 19 and tape guide 18 are constructed integrally and are configured to be controlled to move in the width direction of the running tape 11.

The magnetic head 19 is brought into contact with different positions in the width direction of the tape 11 depending on the position in the moving direction, that is, the height position, and forms a large number of recording tracks on the tape 11 in the width direction. For magnetic head 1
At step 9, for example, recording and reproduction of a video signal is performed.

In such an endless tape device, when recording and reproducing video signals, it is necessary to run the tape 11 at a high speed of several meters per second. A large number of tracks formed in the width direction of the tape 11 by moving by the track pitch are made continuous each time the tape goes around, so that a video signal over a sufficient time range is continuously recorded.

In this case, the tape 11 is set to have a width of, for example, 172 inches and a length of 100 meters or more in order to perform high-speed running control.

However, in order to record a video signal over a sufficient time range, it is necessary to form a large number of tracks, for example as many as 300, at high density within the width of the tape.

That is, as shown in A-C in FIG. 2, the magnetic head 19 moves so as to come into contact with the tape 11, which is running with a regulated height, in the range from the lower end to the upper end. be done.

However, in this case, the tip portion of the magnetic head 19 is set to protrude from the tape sliding surface of the tape guide 18 in order to make contact with the tape 11 with sufficient pressure, and the tip portion of the magnetic head 19 is set to protrude from the tape sliding surface of the tape guide 18 and correspond to the tip portion of the head 19. The tape 11 is then deformed and projected.

In particular, when the magnetic head 19 comes into close contact with the side edge of the tape 11, as shown in Figures A and 0,
The tape deformation force acts in a direction opposite to the side edge.

Therefore, even if the height position of the tape 11 is set using the guide poles 17a and 17b, at the position where the tape 11 actually contacts the magnetic head 19, the tape 11 is displaced within the range shown by E in the figure. Head 1 at the side edge of
Corresponding to the moving position of 9, it becomes impossible to contact the tape 11.

That is, a large number of tracks are formed at minute pitches in the width direction of the tape 11, and the magnetic head 19 is directed to these tracks.
It becomes difficult to accurately control tracking.

This offset position E changes depending on the inclination of the tape guide 18 with respect to the running surface of the tape 11 and the amount of protrusion of the head 19. However, if the amount of head protrusion is specified and there is no inclination of the tape guide 18, A and B in Figure 2
, C, the offset positions E are shown in FIG. 3 as al, bl,
The states are respectively indicated by cl.

When the inclination of the tape guide 18 is, for example, X, the eccentric position becomes a state shown by a2t b2t c2, and this has been confirmed through experiments.

This idea was developed in consideration of the above points, and even when the magnetic head comes into contact with a position close to the side edge of the tape, no force of deviation in the width direction is applied to the running tape, and the force in the width direction of the tape is It is an object of the present invention to provide a magnetic head device in which the position of the magnetic head and the position in the width direction of the tape in contact with the magnetic head correspond accurately over the entire area, and head tracking can be performed with high precision.

An embodiment of this invention will be described below with reference to the drawings.

FIG. 4 shows its configuration, in which the magnetic head 19 is attached and fixed to a support base 21 via a base 20, and a tape guide 22 is integrally attached to this support base 21. established in

As shown in FIG. 5, the tape guide 22 is formed into a curved surface that protrudes along the running direction of the tape 11, and is formed into a cylindrical surface extending in the width direction of the tape 11. A notch groove 23 having a specified width is formed on the tape sliding surface of the guide 22 along the tape running direction.

Then, the tape guide 2 corresponds to this notch groove 23.
A through hole is formed in the back surface of the tape guide 22, and the magnetic head 19 is attached to the through hole with its chip portion protruding from the tape sliding surface of the tape guide 22.

Here, the width of the notch groove 23 is equal to the width of the protruding magnetic head 19.
The length range of the cutout groove 23 may be a range corresponding to the range in which the tape 11 is deformed, and the length range of the notch groove 23 may be a length range that exceeds the range in which the tape 11 comes into contact with the running sliding contact.

The support base 21 in which the magnetic head 19, tape guide 22, etc. are integrated in this way is integrally provided with a guide rod 24 in a vertical shape that coincides with the width direction of the tape 11. The housing 25 is fixedly set.
A pair of upper and lower legs 25 a and 25 b are horizontally arranged.
The support base 21 is inserted into a guide hole formed in the tape width direction, and is guided to move in the vertical direction along the tape width direction.

Further, between the legs 25a and 25b, a vertical screw shaft 26 is rotatably supported, and this screw shaft 26 is engaged with a blade 27 forming a female thread on the support base 21 to rotate the waist screw shaft 26. The support base 21 is controlled to move up and down.

Since this screw shaft 26 is rotationally driven by a pulse motor 29 via a reduction gear mechanism 28, by controlling the rotation angle of this pulse motor 29 using, for example, a microcomputer, the magnetic head 19 can be adjusted to a track pitch. It will be moved accordingly.

That is, in the apparatus configured as described above, the fifth
When shown in cross section along a line passing through the magnetic head 19 indicated by the line O- in FIG.

Furthermore, when a cross section is taken at a position away from the head position indicated by the 0-J line or the O-L line, the states shown in A-C in Fig. 7 correspond to the respective head positions A-C in Fig. 6. Become.

In this case, as shown in FIG. 6B, if the head 19 is located at the center of the tape 11 in the axial direction, the head 19
The force due to the protrusion is equalized with the force in the width direction of the tape 11, and no deflection force acts on the tape 11 as shown by B in FIG.

On the other hand, in the axial state where the head 19 is in close contact with the side edge of the tape 11, as shown in A or B of FIG. acts.

In addition, in the state shown in FIG. 7, the tape 11 is deformed in a depressed state by the notch rR23 at the position where the head 19 is present, and the forces F1' and F2 are opposite to the forces Fl and F2 in FIG.
' is applied.

That is, considering the elongated range along the longitudinal direction of the tape 11 that corresponds to the notch groove 23 of the tape guide 22, the convex curved surface of the tape guide 22 becomes as shown by the chain line in FIG. In the range outside of the range shown by solid line B, the actual lengths are the same.

Therefore, the bending rigidity of the tape 11, the tape guide 22
By appropriately selecting the winding angle of the head 19, the protrusion amount of the head 19, the width of the notch groove 23, and the range, the amount of convex deformation and the amount of severe deformation of the tape 11 can be matched, and the deflection force F1 and F
l' and F2' can be matched and cancelled.

In other words, the positional deviation E of the tape 11 shown in FIG. 2 does not occur.

In this case, when the amount of protrusion of the head 19 is large, the tension on the tape 11 becomes large, and at this time, the amount of denting shown in FIG. The change in the amount of protrusion caused by this is an acceptable condition.

This has been confirmed through experiments; for example, the tape wrapping angle of the tape guide 22 is set to 40 degrees, and the width of the notch groove 23 is set to 2.
In the case of TIrIIL, the protrusion amount of the head 19 is 30~
Even with a change of about 50 μm, no deviation of the tape 11 occurred.

As described above, according to this invention, the deflecting force acting on the tape can be effectively canceled by the head protruding from the tape guide, and therefore the head can be moved to reach both edges of the tape. Even when performing head tracing, it is possible to accurately set the trace position, and its practical effects are particularly significant when used in tape devices that form a large number of recording tracks in the tape width direction at high density. It is something.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram illustrating a tape device related to this invention, Fig. 2 is a diagram illustrating the relationship between the head mechanism and the tape, Fig. 3 is a curve diagram illustrating the tape deflection state, and Fig. 4
The figure is a sectional view showing a head device according to an embodiment of the invention, A in FIG. 5 is a perspective view showing the tape guide section, B is a plan view, and FIGS. B's O-
FIG. 8 is a diagram illustrating the state of the tape at a cross-sectional position along the line 0-J or 0-L, and FIG. 8 is a diagram illustrating the trajectory of the tape relative to the tape guide. DESCRIPTION OF SYMBOLS 11... Tape, 14... Head mechanism, 19... Magnetic head, 21... Support base, 22... Tape guide, 23・・・・・・
... Notch groove, 26 ... Screw shaft, 29 ...
...Pulse motor.

Claims (1)

[Scope of utility model registration request] A tape guide is provided with a curved surface that protrudes from the sliding surface of the running tape in accordance with the running direction and extends in the width direction of the tape. The tape guide includes a magnetic head integrally provided so as to protrude, and a mechanism for controlling the movement of the magnetic head in the tape width direction together with the tape guide. What is claimed is: 1. A magnetic head device comprising: a notch groove having a width specified with respect to the tape width direction and extending at least beyond the sliding contact range along the running direction of the tape.