JPH03187058A - Rotary head device - Google Patents

Abstract

PURPOSE:To support a magnetic head perpendicularly to the recording face of a magnetic tape by forming the lower face of a rotating drum so that its section in the radial direction is sawtoothed shaped and attaching a head base perpendicularly to the direction of a revolving shaft. CONSTITUTION:The section of a lower face 11b of a rotating drum 11 is formed to sawtoothed shape. Then, a head base 3 has the upper face brought into contact with respective projecting front end parts 11d and is kept perpendicular to the axial direction of a revolving shaft when the base 3 is attached to the lower face 11b. As the result, a magnetic head H set to the base 3 is supported in the direction perpendicular to the recording face of a magnetic tape 7. Sawtooth on the lower face 11b function as air film preventing grooves. Consequently, the formation of an air film is prevented when the upper face is brought into contact with the lower face 11b to attach the base 3, and deviation of the base 3 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotating head device for a magnetic recording/reproducing device in which a head base on which a magnetic head is attached is attached to the lower surface of a rotating drum. The present invention relates to a rotating head device that can prevent a head base from shifting due to an air film during installation.

[Prior Art 1] Figure 11!4 is a front view showing a conventional rotary head device for a magnetic recording/reproducing device.

Reference numeral 1 in the figure indicates a rotating drum. This rotating drum 1 is fixed to a rotating shaft 2 and rotates therewith, or is rotatably supported on the shaft.

Further, a head base 3 on which a magnetic head H is mounted is fixed to the lower surface of the rotating drum 1 with a mounting screw 3a (see FIG. 5). Further, a fixed drum 4 is provided below the rotating drum 1 and is fixed to a chassis 6.

On the other hand, reference numeral 7 indicates a magnetic tape, and this magnetic tape 7 is pulled out from the cassette half by a loading member such as a guide roller 8 on the left side (inlet side) of the figure, and wound onto the drum 1 for one rotation and the fixed drum 4. Can be attached. During a recording or reproducing operation, the magnetic tape 7 is sent out toward each drum 1.4 via the guide roller 8 by the rotational driving force of the capstan, and then sent out through the guide roller 9 on the right side (exit side) in the figure. It is sent back to the cassette half via the cassette.

Further, the recording tracks on the magnetic tape 7 are formed slightly inclined at a predetermined track angle with respect to the tape running direction (direction of arrow α in the figure). Therefore, each of the drums 1.4i3 and the rotating shaft 2 are tilted by an angle θ with respect to the tape running direction α so that the magnetic head H can scan the recording track. On the outer periphery of the fixed drum 4 tilted in this way, a lead ↓0 is formed by a stepped surface parallel to the tape running direction α, with which the lower end surface of the magnetic tape 7 comes into contact. This guide 10 is for guiding the magnetic tape 7 and making it run accurately. That is, the magnetic tape 7 is placed on each drum 1.4 with its lower end surface placed on the stepped surface of the lead 10.
It is designed to run while being wrapped around. In the figure, reference numeral 11 indicates an inclined post that changes the direction of the magnetic tape 7 sent from the guide roller 8 so that the magnetic tape 7 is wound around each drum 1.4 without twisting, and reference numeral 12 indicates an inclined post for each drum. This is an inclined post that changes the direction of the magnetic tape 7 so that the magnetic tape 7 wound around the magnetic tape 7 is sent to the guide roller 9 without twisting.

Further, in FIG. 4, the circumferential surface la of the rotating drum 1 is formed into a tapered surface whose diameter gradually increases as it moves away from the fixed drum 4. Incidentally, the Taper angle of the tapered surface 1a is about 1 to 2.5 μm/2 mm. Like this 1
The reason why the circumferential surface 1a of the rotary drum l is formed into a tapered surface is that this tapered surface applies a downward force to the running magnetic tape 7, thereby causing the lower end surface of the running magnetic tape 7 to lead. This is to ensure that the vehicle travels in a state where it is reliably pressed against the stepped surface of No. 10.

[Problem to be solved by the invention J By the way, when forming such a rotating drum 1,
First, the circumferential surface 1a is formed into a tapered surface, and then the lower surface of the rotating drum 1 is cut using a cutting tool using this tapered surface as a reference surface. And this rotating drum 1
When processing the lower surface of the machine, the performance of the processing machine (3
On the other hand, cutting is performed in a direction perpendicular to the tapered surface 1a. Therefore, conventionally, as shown in FIG. 5, the lower surface 1b of the rotating drum 1 is inclined in a tapered manner with respect to the axial direction of the rotating shaft 2 (indicated by the dashed line A in FIG. 5). As shown in an enlarged view in FIG. 6, there is a problem in that the magnetic head H is tilted downward in the figure with respect to the recording surface of the magnetic tape 7.

Further, the lower surface of the rotating drum l, which is the mounting surface of the head base 3, is finished to have a mirror surface with increased surface roughness in order to improve accuracy. Similarly, the upper surface of the head base 3 is finished to a mirror surface with increased surface roughness to ensure mounting precision. Therefore, when attaching the upper surface of the head base 3 to the lower surface of the rotary drum 1, the mirror surfaces must come into contact with each other, but an air film is generated at this time, and the head base 3 may shift when screwed due to the phenomenon of air tracks. There is a risk of it getting lost.

The present invention is intended to solve the above-mentioned problems, and it is possible to mount the head base perpendicularly to the axial direction of the rotating shaft of the rotating drum, and also to adjust the position of the head base using an air film when the head base is mounted. An object of the present invention is to provide a rotary head device that can prevent misalignment.

[Means to solve the problem]

A rotary head device according to the present invention includes a rotary drum and a head base on which a magnetic head is mounted and attached to the lower surface of the rotary drum, wherein the lower surface of the rotary drum to which the head base is attached is It is characterized by having a sawtooth cross section in the radial direction.

[For production]

According to the above means, the lower surface of the rotating drum is formed so that its radial cross section is serrated. It is possible to form the shaft perpendicularly to the axial direction of the rotation axis of the shaft. Therefore, the head base can be mounted perpendicularly to the direction of the rotation axis, and the magnetic head can be supported perpendicularly to the recording surface of the magnetic tape.

In addition, with the above means, the lower surface of the rotating drum is formed with a serrated cross section, which prevents the generation of an air film when attaching the head base to the lower surface of the rotating drum, and prevents misalignment when screwing the head base. You will be able to do this.

[Example] The present invention will be described in detail below based on the drawings.

Fig. 1 is a sectional view showing a rotating drum of a rotating head device according to an embodiment of the present invention, Fig. 2A-B is a partially enlarged view of Fig. 1, and Fig. 3 shows a head base attached to the rotating drum. It is a partial sectional view showing a state.

A rotating drum 11 shown in FIG. 1 is provided opposite to a fixed drum 4 shown in FIG. 4 to constitute a rotating head device. Further, the rotating drum 11 is rotatably driven by having a rotating shaft 2 shown in FIG. 4 fixed to its center hole 11c via a sleeve or the like. Also rotating drum 1
The peripheral surface 11a of the magnetic tape 1 is a tapered tape whose diameter gradually increases as it moves away from the fixed drum 4 so that the lower end surface of the running magnetic tape 7 (see FIG. 4) is reliably pressed against the lead 10 of the fixed drum 4. formed on the surface.

Further, in this embodiment, as shown in an enlarged view in FIG. 2A, the lower surface 11b of the rotating drum 11 is formed so that its radial cross section is serrated. This serrated cross section is created by using an NC (numerical control) machine tool (such as an NC lathe) when cutting the lower surface 11b with the Taper surface of the peripheral surface 11a of the rotating drum 11 as a reference. Each time a predetermined pitch (see Fig. 2B) is cut in the vertical direction (to form a circumferential groove on the lower surface), the cutting tool is moved in the direction of the fixed drum 4 at a predetermined pitch tm (
(see FIG. 2B). In this case, the predetermined pitches t and t2 are such that the plane connecting each protruding tip lid of the serrated cross section (indicated by the two-dot chain line B in FIG. 2A) is The values are calculated in advance so that they are perpendicular to (indicated by A).

In this embodiment, the pitch t is set to an arbitrary value within the range of 0.1 to 1 mm, and the pitch t2 is set to an arbitrary value within the range of 0.1 to 1 μm.

As described above, according to this embodiment, since the lower surface 11b of the rotating drum 11 is formed with a serrated cross section, when the head base 3 is attached to the lower surface 11b of the rotating drum 11,
As shown in FIG. 3, since the upper surface of the head base 3 is in contact with each protruding tip lid, the head base 3 is maintained in a direction perpendicular to the axial direction of the rotating shaft 2. . Therefore, the magnetic head H mounted on the head base 3 is also supported in a direction perpendicular to the recording surface of the magnetic tape 7.

Further, in this embodiment, as described above, the lower surface 11b of the rotating drum 11 is formed to have a serrated cross section, and this serrated step serves as a groove for preventing air film. Therefore, even when the upper surface of the head base 3 is brought into contact with the lower surface 11b of the rotary drum 11 in order to attach the head base 3, generation of an air film is prevented, and the head base 3 is prevented from shifting when screwed due to the phenomenon of air tracks. will be prevented.

[Effect] As described above, according to the present invention, the lower surface of the rotating drum is formed so that its radial cross section is serrated. It becomes possible to form the other surfaces perpendicular to the axial direction of the rotating shaft of the rotating drum. Therefore, the head base can be mounted perpendicularly to the direction of the rotation axis, and the magnetic head can be supported perpendicularly to the recording surface of the magnetic tape.

In addition, in the above method, since the lower surface of the rotating drum is formed with a serrated cross section, it is possible to prevent the generation of an air film when attaching the helad base to the lower surface of the rotating drum, and prevent the head base from shifting when screwing the head base. You will be able to prevent it from collapsing.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a rotating drum of a rotating head device according to an embodiment of the present invention, Fig. 2A-B is a partially enlarged view of Fig. 1, and Fig. 3 shows a head base attached to the rotating drum. 4 is a front view showing a rotary head device for a conventional magnetic recording/reproducing device; FIG. 5 is a sectional view showing the rotating drum of FIG. 4; and FIG. FIG. 5 is a partially enlarged view showing the rotating drum and the stationary drum of FIG. 4; H...Magnetic head, 3...Head base, 11...
・Rotating drum, llb...lower surface of the rotating drum.

Claims (1)

[Claims] 1. In a rotating head device including a rotating drum and a head base to which a magnetic head is attached and attached to the lower surface of the rotating drum, the lower surface of the rotating drum to which the head base is attached has a sawtooth cross section in the radial direction. A rotating head device characterized by being formed in