JPH0541001A - Rotary magnetic head device - Google Patents

Abstract

PURPOSE:To reduce damage to a magnetic tape due to an edge projecting from the lower end of the window, and to uniformize a face contact state between the head and the tape, in a rotary magnetic head device of helical scan system. CONSTITUTION:The lower part of the chamfered state window 10 formed for making the head 5 to project to the lower edge of an upper drum 4 is covered by mounting a balancer 11 which is a disk like ring, on the lower edge of upper drum 4. The damage to the tape due to the edge at the lower end of window is reduced by means of covering the lower end of window 10 of the upper drum 4 with the balancer 11, and also a contact balance for the head and tape can be uniformized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a heli-cal scan type rotary magnetic head device used in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art An example of a conventional heli-cal scan type rotary magnetic head device will be described with reference to FIG. In the figure, 1
Is a fixed side cylinder, 2 is a shaft flange mounted on the fixed side cylinder 1 through two bearings 3, 4 is an upper drum which is fixed to the shaft flange 2 and rotates, and 5 is an upper drum carried by the upper drum 4. Four
Head projecting a head chip from the window of 6, a terminal transformer 6 for extracting a signal from the head 5, a rotary transformer 7 for transmitting the signal transmitted from the terminal transformer 6 to a fixed side, and a driving force 8 for the upper drum. Shows the motor that gives.

Next, the operation will be described. In a magnetic recording / reproducing apparatus having a heli-cal scan type rotary magnetic head device, a fixed side cylinder 1 of the rotary magnetic head device is provided.
With respect to the magnetic tape wound along the lead groove 9 provided on the outer periphery of the head drum, the tip of the tip of the head 5 attached to the upper drum 4 rotated by the motor 8 is passed through the window 10 of the upper drum 4. Signals are delivered by sticking out and coming into contact with the tape. Next, the signal is transmitted to the rotary transformer 7 via the terminal transformer 6, where the signal is transmitted from the rotating side to the fixed side.

[0004]

Since the conventional rotary magnetic head device is constructed as described above, the tip of the head 5 attached to the bottom surface of the upper drum 4 is projected to the outside of the upper drum 4. When this is done, it is necessary to provide a window (notch) as shown by reference numeral 10.
Since there is a gap between the lower part of the and the fixed side cylinder 1, the tape is swept in here, the tape is damaged at the lower edge of the window, and the contact between the head and the tape becomes unstable, so it is well balanced. There was a problem that signals could not be passed. In Japanese Patent Laid-Open No. 60-645, the cylindrical surface of the upper drum around the window provided at the lower end of the upper drum for projecting the tip end of the head is cut off slightly flat so that Although it has been disclosed to prevent the tape from being worn by a portion, it is impossible to make the contact between the head and the tape uniform. Also, Japanese Utility Model Laid-Open No. 1-151442 discloses that a gap between the head and the window is filled with a filling member so that the tape is not sucked into the window. Movement control is not possible.

The present invention has been made to solve the above-mentioned problems, and eliminates the tape damage at the lower end of the window 10 provided in the upper drum 4, and the head 5
The purpose is to make the contact with the tape even.

[0006]

In the rotary magnetic head device according to the present invention, the lower portion of the window at the lower end of the upper drum is covered with, for example, a disc-shaped ring.

[0007]

In the rotary magnetic head device according to the present invention, by covering the lower end of the window at the lower end of the upper drum, the tape damage due to the edge of the lower end of the window is eliminated, and the contact between the head and the tape becomes uniform.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, 11 is a balancer, which is a disk-shaped ring attached to the lower end of the upper drum 4, and the other components are all the same as those shown in FIG. As can be seen from this figure, the lower end of the window 10 for projecting the head 5 is covered with a balancer 11.

FIG. 2 shows the essential parts of another embodiment of the present invention. The outer diameter of the balancer 11 in this embodiment has a diameter between the inner diameter D ₁ of the R dimension at the lower end of the upper drum and the outer diameter D ₂ of the upper drum.

In these two embodiments, the balancer 11
Is adhered to the lower end of the upper drum 4 to close the lower end of the window 10 of the upper drum 4. However, the balancer 11 may be fixed to the lower end of the upper drum 4 by screwing or the like instead of adhering.

Further, the balancer 11 may be fixed to the lower end of the upper drum 4 by press fitting as shown in FIG.

In the above embodiment, the upper drum 4
1 which is a separate member for covering the lower end of the window 10 of
1 was attached to the lower end of the upper drum 4, but the upper drum 4 was perforated as shown in FIG.
The balancer 11 may be integrated.

[0013]

As described above, according to the present invention, since the lower end of the window 10 of the upper drum 4 is covered, the edge of the lower end of the window 10 does not damage the tape, and the head 5 of the head 5 is not damaged. The amount of tape sucked up and down is stable, and it is possible to make uniform contact between the head and the tape.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing a rotary magnetic head device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main part of another embodiment of the present invention.

FIG. 3 is a diagram showing a main part of another embodiment of the present invention.

FIG. 4 is a diagram showing a main part of another embodiment of the present invention.

FIG. 5 is a side view of a partial cross section showing a conventional rotary magnetic head device.

[Explanation of symbols]

 1 Fixed cylinder 2 Shaft flange 3 Bearing 4 Upper drum 5 Head 6 Terminal transformer 7 Rotary transformer 8 Motor 9 Lead groove 10 Window 11 Balancer

Claims (1)

[Claims] 1. A rotary magnetic head device having a fixed cylinder, an upper drum, and a head carried by the upper drum and protruding from a window at the lower end of the upper drum, wherein the lower end of the window is covered. And a rotating magnetic head device.