JPS63298744A - Rotary head assembly for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To contrive the stabilization of the signal transmission between a recording/reproducing head and a magnetic tape by stabilizing and uniformizing the deformation of a magnetic tape over the entire range of a magnetic tape wound onto a stationary cylinder. CONSTITUTION:A recessed part 504 is formed in axial direction to an upper end face of a stationary cylinder 503 from a winding start point A till a point P being this side from a winding medium point B to increase the lower space 14 of a head chip 101 than the other space in the range of the recessed part. Thus, the part not supported by the stationary cylinder 5A of a magnetic tape is increased and the part is fallen toward the inner part in the radial direction at the space 14 to stabilize and uniformize the deformation of the magnetic tape over the entire winding range of the magnetic tape onto the stationary cylinder 5A. Thus, the signal transmission between the recording/reproducing head 1 and the magnetic tape is made stable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotary head assembly of a magnetic recording/reproducing device such as a video tape recorder (hereinafter abbreviated as VTR), and particularly to a tape-shaped recording medium and a recording medium. This invention relates to improving the stability of signal transmission between the playback head and the playback head.

[Conventional technology]

A conventional V'l'H rotary head assembly is shown in FIGS. 4-8.

4 is a perspective view of the rotating head assembly, FIG. 5 is a partial vertical sectional view, FIG. 6 is a plan view showing the winding of a tape-shaped recording medium around the rotating head assembly, and FIG. 7 is an A shown in FIG. 6. , B, and C are longitudinal cross-sectional views showing the deformation of the tape-shaped recording medium in the vicinity of the recording/reproducing head. It is a graph showing the distribution of the axial distance (Y) in the circumferential direction.

In the figure, (1) is a recording/reproducing head, which includes a head chip (101) and a head base (102) that supports it.
) and supported by a rotating cylinder (2). The rotating cylinder (2) is attached to a flange (3) fixed to the rotating shaft (4), and the rotating shaft (4) is connected to the fixed cylinder (5) by ball bearings (6), (7) attached to it.
and is supported by an end ring (8). (9)
is a magnetic tape which is a tape-shaped recording medium, (lO) is a rotary transformer on the rotating side attached to the bottom surface of the 7 langes (3), and (11) is a fixed cylinder (5) opposite to the rotary transformer on the rotating side (lO). This is the installed fixed side rotary transformer.

Next, referring to FIG. 6, the state in which the magnetic tape is wound around the rotary head assembly is shown.
The magnetic tape (9) is attached to the outer peripheral surface (50) of the fixed cylinder (5).
It is guided obliquely on the outer peripheral surface (501) along the lead groove (502) (Fig. 5) formed in the lead groove (502) formed in the arrow (1').
12). The rotating cylinder (2) is indicated by the arrow (
13) (Figure 4).

(A) is the winding start point where the magnetic tape (9) begins to wind around the fixed cylinder (5), (B) is the winding center point, (C)
is the separation point where the magnetic tape (9) separates from the fixed cylinder (5).

The axial distance (Y) (Fig. 7) between the head chip (101) and the upper end surface (503) of the outer circumference of the fixed cylinder (5) facing its rotational orbit is fixed as shown in Fig. 8. It is uniform over the entire circumference of the cylinder (5).

By the way, there is magnetic tape (
Focusing on the deformation in the vicinity of the magnetic head (1) when viewed in the direction of the rotational axis ('401) when 9) is wound, it can be seen that on the rotating cylinder (2), the formation of an air film due to its rotation causes it to float. Since this does not have the function of forming an air film, it hardly floats above the fixed cylinder (5), and the outer peripheral surface of the fixed cylinder (5)
501) The vehicle is running almost in contact with the vehicle. In addition, the flying height above the rotating cylinder (2) is
The deformation of the magnetic tape (9) at the winding start point (A) is as shown in Fig. 7 (9A), and the winding center point (B) and the departure point (C) are as shown in (9B). That is, near the winding start point (A), the flying height on the rotating cylinder (2) is larger than the flying height at the center point (B) and the separation point (C), and moreover, the flying height on the rotating cylinder (2) is larger than that at the center point (B) and the separation point (C). ) to the lower end of the head chip (101), the tape tension component inward in the radial direction of the magnetic tape (9) below the head chip (101) is weak.
1) The magnetic tape (9) shows a tendency to float at the bottom.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional rotating head assembly,
The deformed shape of the magnetic tape on the lower side of the head chip (101) is different between the vicinity of the winding start point (A) and the other parts. Since the magnetic tape (9) tends to separate from the head chip (101) below 01), the gap between the head chip (101) and the magnetic tape (9) near the winding start point (A) However, there is a problem in that an unstable contact state occurs, and therefore, signal transmission becomes unstable.

The present invention has been made in order to solve the above-mentioned problems with conventional devices, and provides a rotary head assembly for a magnetic recording/reproducing device that can stably transmit signals between a magnetic recording/reproducing head and a magnetic tape. The purpose is to

[Means for solving problems]

The rotating head assembly according to the present invention has an axial recess formed in the upper end surface of the outer peripheral part of the fixed cylinder, facing the rotational trajectory of the head chip from the winding start point to a point before the winding center point, The distance between the rotating orbit of the head chip and the outer peripheral portion of the fixed cylinder is made larger in the recess than in other parts.

[Effect]

In this invention, since the space under the head chip from the winding start point to the point before the winding center point is larger than other parts, the part of the tape-shaped recording medium that is not supported by the fixed cylinder becomes large. The drop inward in the radial direction increases.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a perspective view of a rotary head assembly according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the rotation orbit of the head chip and the upper end surface of the outer circumference of the fixed cylinder in the embodiment of FIG. 1. FIG. 3 is a graph showing the circumferential distribution of distance; FIG. 3 is an axial cross-section of a portion of the rotary head assembly at the start of winding, illustrating the deformation of the magnetic tape; Note that the same parts as in the conventional one are given the same reference numerals, and the explanation thereof will be omitted.

In the figure, (5A) is a fixed cylinder corresponding to (5) of the conventional one, and a magnetic tape (9) is mounted on the upper end surface (503) of the outer periphery facing the rotational orbit of the head chip (101) in the axial direction. An axial recess (504) extends from the winding start point (A) where winding begins to the fixed cylinder (5A) to a point (P) before the winding center point (B).
The axial distance (Y) between the rotation orbit of the head chip and the upper end surface (503) of the outer peripheral part of the fixed cylinder is made larger in the recess (504) than in other parts. (Figure 2). Preferably, the depth of said recess (504) and therefore also said distance decreases linearly from the winding starting point (A) to said point (P) as shown in FIG.

In this way, from the winding start point (A) to the winding center point (B)
Fixed cylinder outer periphery (503) up to the point (P) in front of you
By forming an axial recess (504) in the upper end surface, the space (14) below the head chip (101) becomes larger than the other part of the space in the range of this recess, so that the magnetic tape The portion that is not supported by the fixed cylinder (5A) of (9) increases and this portion falls radially inward in the space (14).

As a result, at the winding start point (A), the magnetic tape (9) is (
9C), and at point (P), Cζ deforms as shown in (9D). (9C) is almost equal to the deformation (9B) at the winding center point (B), and (9D) is the deformation (9B
), and therefore the magnetic tape (9) is wrapped around the fixed cylinder (5A) over the entire range.
Since the deformation of 9) is stable and equalized, the recording/reproducing head (
1) and the magnetic tape (9) is stabilized. Furthermore, by decreasing the depth of the recess (504) linearly from the winding start point (A) to the point (P) as in the illustrated embodiment, the space (504) below the head chip (101) can be The size also decreases linearly from point (A) to point (P), and the deformation of the magnetic tape (9) can be made smooth from (9C) to (9D). recess (
The circumferential range and depth of the magnetic tape (9) can be appropriately determined for each model through testing, but the circumferential range is determined by the winding range of the magnetic tape (9) on the fixed cylinder (5A) (
In the case shown in the figure, regardless of the angle 1800), the range may be approximately 20% of the tape winding angle from the tape winding start point (A).

That is, in reality, the deformation (9A) of 9) becomes a problem in the magnetic tape within a range of about 30 degrees from the winding start point (A). In addition, the depth of the recess (504) is the same as that of the upper end surface (503) of the outer peripheral part of the fixed cylinder and the head chip (1).
01) where the distance between the vertical center and the vertical center is approximately 0.5 m, it is recommended that the depth at the winding start point (A) be 0.7 tx -1, Otx. . 0.
If it is less than 7 fl, the amount of fall of the magnetic tape (9) inward in the radial direction in the space (14) will be insufficient, and it will be 1.0 fl.
If the value is more than am, the amount of inversion will become too large.

Note that if the recess (504) is formed slightly (for example, about 100 mm) before the winding start point (A) as shown by the imaginary line in FIG. 2, the deformation (9C) at the point (A) can be reduced. It is possible to get even closer to (9B), and the present invention also includes such a method.

〔Effect of the invention〕

As described above, according to the present invention, the deformation of the magnetic tape is stabilized over the entire range where the magnetic tape is wound around the fixed cylinder due to the extremely simple structure of forming a recess in a predetermined portion of the upper end surface of the outer circumference of the fixed cylinder. Since it is equalized,
This provides the effect of stabilizing signal transmission between the recording/reproducing head and the magnetic tape.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a rotary head assembly according to an embodiment of the present invention, and FIG. 2 is an axis between the rotation orbit of the head chip and the upper end surface of the outer circumferential portion of the fixed cylinder in the embodiment shown in FIG. 1. Graph showing the distribution of directional distance in the circumferential direction. FIG. 3 is an axial cross-sectional view of a portion of the rotary head assembly at the starting point of winding, showing the deformation of the magnetic tape. FIG. 4 is a diagram showing the conventional rotary head. perspective view of the assembly;
FIG. 5 is a partial vertical sectional view, FIG. 6 is a plan view showing the winding of the tape-shaped recording medium around the rotary head assembly, and FIG.
The figure is a longitudinal cross-sectional view showing the deformation of the tape-shaped recording medium near the recording/reproducing head at each point A, B, and C shown in FIG.
FIG. 8 is a graph showing the distribution in the circumferential direction of the distance between the rotating orbit of the head chip and the upper end surface of the outer circumferential portion of the fixed cylinder opposed thereto in the one shown in FIG. In the figure, (1) is a recording/reproducing head, (101) is a head chip, (2) is a rotating cylinder, (5A) is a fixed cylinder, (501) is its outer peripheral surface, (503) is the upper end surface of the outer peripheral part, ( 504) is a recess, (9) is a tape-shaped recording medium (magnetic tape), (A) is a winding start point, and (B) is a winding center point. Agent Patent Attorney Masuo Oiwa 1st figure l1cl Enkata Sosa! → Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A rotary head assembly for a magnetic recording/reproducing device comprising a rotating cylinder that holds a recording/reproducing head and a fixed cylinder that rotatably supports the rotating cylinder and guides a tape-shaped recording medium on its outer peripheral surface. An axial recess is provided on the upper end surface of the outer peripheral portion of the fixed cylinder, facing the rotational trajectory of the head chip of the recording/reproducing head from the winding start point where the recording medium starts to be wound around the fixed cylinder to a point before the winding center point. 1. A rotary head assembly for a magnetic recording/reproducing device, characterized in that a rotary head assembly is formed therein. (2) A rotary head of a magnetic recording and reproducing device according to claim 1, characterized in that the depth of the recess is linearly reduced from the winding start point to a point before the winding center point. assembly.