JP3106512B2 - Rotating head 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 rotary head device for obtaining a stable contact state between a magnetic head and a magnetic tape in a helical scan type magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art Hitherto, helical scan type rotary head devices have been used in magnetic recording / reproducing devices such as video tape recorders. In the conventional rotary head device, the gap between the rotary drum and the fixed drum has a constant size from the entrance side to the exit side of the magnetic tape (hereinafter referred to as tape).

FIG. 4 is a plan view of a conventional rotary head device.
FIG. 5 shows a side view. 4 and 5, reference numeral 1 denotes a tape guided by a guide post 2 and wound around a rotating drum 3 and a fixed drum 4. 5 is a magnetic head. Here, the size f of the gap between the rotating drum 3 and the fixed drum 4 shown in FIG. 5 is constant with respect to the tape winding angle θ. That is, it is constant from the tape entry side 6 to the output side 7.

[0004]

In the above conventional example, the gap between the rotary drum 3 and the fixed drum 4 has a constant dimension from the tape entry side to the tape exit side, while the tension of the tape 1 is reduced. There is a problem that the contact state between the tape 1 and the rotary head 3 changes since the tape 1 changes from the entry side to the exit side.

This problem will be described in more detail with reference to FIGS. 7A and 7B. FIG. 7A is a vertical sectional view including the magnetic head at the magnetic tape entrance 6 in FIG. 4, and FIG. 7B is a similar vertical sectional view at the magnetic tape exit 7. As described with reference to FIG. 5, the gap size f between the lower edge of the rotating drum 3 and the upper edge of the fixed drum is constant from the magnetic tape inlet 6 to the magnetic tape outlet 7. Therefore, the dimension g between the lower end of the rotating drum and the upper surface of the magnetic head 5 in the magnetic head mounting window 3a in FIG. The dimension h with respect to the lower surface of the head 5 is also constant. However, the magnetic tape 1 at the entrance 6
Increases as the wrap angle θ increases in the direction of the outlet 7. Therefore, at the entrance 6, the magnetic tape 1 is affected by the tension, as shown in FIG.
Although a depression amount of 1 is generated, the tension amount at the outlet 7 increases, so that the depression amount increases to x2 and y2 as shown in FIG. 7B. As a result, the contact force between the magnetic head 5 and the magnetic tape 1 increases as the tape winding angle θ from the entrance 6 increases. This relationship is illustrated by the line c in FIG. Therefore, there is a problem that the level of the recording / reproducing signal is different between the entrance 6 and the exit 7.

[0006] The present invention solves the above problems, and even if there is a change in the tension of the magnetic tape 1 between the inlet 6 and the outlet 7,
And its object is to provide a Ru can be a contact force between the magnetic tape 1 and the magnetic head 5 at a constant rotating drum device.

[0007]

In order to achieve the above object, the present invention provides a fixed drum for guiding a magnetic tape and the fixed drum.
Rotating drum supported rotatably above the fixed drum and the front
And a magnetic head mounted on the lower surface of the rotating drum.
The magnetic tape is fixed to the fixed drum and the rotating drum.
Under the magnetic head at the entry side when it is wound around
The gap between the surface and the upper surface of the fixed drum is h1,
The magnetic tape is transferred to the fixed drum and the rotating drum.
The lower surface of the magnetic head on the exit side when wound
When the gap with the upper surface of the fixed drum is h2, h1
> By configuring such that the relationship of h2, rotating head and the contact force between the front Symbol magnetic tape before Symbol magnetic head at the inlet side of the apparatus, SL before the outlet side tape before <br/> Symbol The difference between the contact force with the magnetic head and the contact force between the magnetic tape and the magnetic head is reduced to reduce the difference between the contact force and the magnetic head.

[0008]

According to the present invention, since the contact force between the tape and the magnetic head at the tape entrance and exit is small, the present invention can provide a stable contact state between the magnetic head and the tape. Recording and reproduction output can be stabilized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a rotary head device according to an embodiment of the present invention, and FIG. 2 is a side view. 1 and 2, reference numeral 1 denotes a tape guided by a guide post 2 and wound around a rotary drum 3 and a fixed drum 4. 5 is a magnetic head. The traveling direction of the tape and the rotating direction of the rotating drum are as indicated by arrows. Here, the upper surface of the fixed drum 4 is the lower surface of the magnetic head 5
Are formed so as to be oblique with respect to the plane formed by the rotation locus of the magnetic head 5, and the size of the gap between the lower surface of the magnetic head 5 and the fixed drum 4 is h1 on the input side 6 of the tape, h2 on the output side 7, and h1
> H2, during which time it decreases continuously as the winding angle θ increases.

By setting the gap between the rotating drum and the fixed drum to be h1> h2, as shown in FIGS.
As shown in (b), the tape depression amounts x3 and y3 at the tape entrance are the depression amounts x4 and y4 at the tape exit.
And the amount of change in the depression between the inlet and the outlet is as shown in FIG.
It is smaller than in the case of the conventional example shown in FIG.
Thus, the contact force between the tape 1 and the magnetic head 5 is reduced as shown in FIG.
The change in the contact force is smaller than that of the conventional c-line. Therefore, the contact state between the tape 1 and the magnetic head 5 is stabilized, and the recording / reproducing output is also stabilized.

[0011]

As described above, according to the present invention, with a simple structure, the gap between the rotating drum and the fixed drum from the tape entry side to the tape exit side is changed to reduce the change in the tape depression amount. Accordingly, it is possible to provide a rotary head device in which the tape and the magnetic head are stably contacted.

[Brief description of the drawings]

FIG. 1 is a plan view of a rotary head device according to an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a diagram showing a relationship between a contact force between a tape and a magnetic head and a winding angle;

FIG. 4 is a plan view of a conventional rotary head device.

FIG. 5 is a side view of the same.

[6] (a) a tape in rotation head device of an embodiment of FIG. (B) The present invention showing a contact state between the magnetic head and the tape in the tape inlet in rotation head apparatus of one embodiment of the present invention The figure which shows the contact state of a magnetic head and a tape in an exit

7A is a diagram showing a contact state between a magnetic head and a tape at a tape entrance in a conventional rotary head device. FIG. 7B is a diagram showing a contact between a magnetic head and a tape at a tape exit in a conventional rotary head device. Diagram showing status

[Description of Signs] 1 Magnetic tape 3 Rotary drum 4 Fixed drum 5 Magnetic head h1 Distance between lower surface of magnetic head and upper surface of fixed drum at entrance side h2 Distance between lower surface of magnetic head and upper surface of fixed drum at exit side

Claims (1)

(57) [Claims] 1. A fixed drum for guiding a magnetic tape, a rotating drum rotatably supported above the fixed drum, and a magnetic head mounted on a lower surface of the rotating drum, wherein the magnetic tape is fixed to the fixed drum. And a gap between the lower surface of the magnetic head and the upper surface of the fixed drum at the entry side when the magnetic tape is wound around the rotating drum is h1, and the gap at the exit side when the magnetic tape is wound around the fixed drum and the rotating drum is When a gap between the lower surface of the magnetic head and the upper surface of the fixed drum is h2, h
1> h2 so that the upper surface of the fixed drum is
Inclined with respect to the plane created by the rotation trajectory of the lower surface of the magnetic head
A rotary head device having a configuration in which the rotary head is formed.