JPH01204268A - Control board - Google Patents

Abstract

PURPOSE:To obtain stable head touch by providing a projecting part, which presses the outer peripheral part of a magnetic sheet, in a control board and continuously or intermittently inclining the pressing surface of the projecting part more deeply in the inner peripheral side. CONSTITUTION:In the upstream side and downstream side of a groove-shaped recessed part 16 to be formed in the center of a control board 15, inclining surfaces 17 and 18 are respectively obtained and a projecting part 19 is provided on the outer peripheral side of the specifying board 15. Then, the magnetic sheet is pressed by this projecting part 19. The outer peripheral side of the projecting part 19 in a magnetic head moving direction is hollowed as a pressing surface 20 and made in a circular arc shape with step. Accordingly, when a magnetic head 4 slides and contacts a magnetic sheet 1 in the inner peripheral side, an outer peripheral part 20a and the magnetic sheet 1 smoothly is brought into contact and when the magnetic head 4 slides and contacts the magnetic sheet 1 in the outer peripheral side, an inner peripheral part 20b is smoothly brought contact with the magnetic sheet 1. Thus, even when the magnetic head 4 moves to the inner and outer peripheries, the stable head touch can be always obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention relates to an improvement of a regulating plate used in a device for recording and reproducing video signals and various digital signals on a rotating magnetic sheet.

<Prior Art> In order to stably and reliably record and reproduce video signals and the like on a rotating magnetic sheet, good sliding contact between the magnetic sheet and a magnetic head is required. For this reason, conventionally the fifth
A regulating plate is used as shown in the figure. That is, a disk-shaped magnetic sheet 1 has a center core 2 fixed to its center, and this center core 2 is chucked by a spindle 3 and rotated at high speed. A magnetic head 4 is mounted on the magnetic sheet 1 facing the recording surface of the magnetic sheet 1.
are arranged so as to be movable in the radial direction.

A regulation plate 5 is arranged with respect to the magnetic head 4, sandwiching the magnetic sheet 1 at λ. The shape of this regulation plate 5 is 6th.
The one shown in the figure is common, and a groove-like recess 6 is formed in the center along the moving direction of the magnetic head 4.

Several drawbacks have been pointed out to the regulating plate 5 having such a general shape.

One of them is that the magnetic sheet 1 is flexible, so when the magnetic head 4 is pressed against it, it bends more toward the outside in the radial direction, as shown in FIG. Therefore, the state of contact between the magnetic head 4 and the magnetic sheet 1 differs between the inner circumferential side and the outer circumferential side. In other words, as shown in FIG. 7, although the magnetic sheet 1 contacts the magnetic head 4 on its inner circumferential side, the outer circumferential side of the magnetic sheet 1 floats up and cannot make stable contact with the magnetic head 4.

Therefore, in the rotating magnetic sheet device according to Japanese Patent Application No. 59-76939, as shown in FIG. is corrected so that the magnetic sheet 1 is brought into contact with the entire surface of the magnetic head 4.

<Problems to be Solved by the Invention> However, since the convex portion 7 provided on the regulating plate 5 shown in FIG. At times, force was applied. In particular, I wanted to move the magnetic head 4 to the outermost circumference.
The distance between the magnetic head 4 and the convex part 7 becomes narrower, and the magnetic sheet 1 curves greatly between this gap and comes into contact with the convex part 7 at a deep angle, so that running traces may remain on the back surface of the magnetic sheet 1.

That is, when the magnetic head 4 was moved, the contact state between the magnetic sheet and the convex portion 7 of the regulating plate 5 changed, and as a result, a stable head touch could not be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above and to provide a regulating plate that can always provide stable head touch even when the magnetic head 4 moves toward the inner and outer peripheries.

Means for Solving the Problems> The structure of the present invention to achieve the above object is to press the outer circumferential portion of the magnetic sheet to a regulating plate facing the magnetic head with the rotating magnetic sheet interposed therebetween, and to form a convex portion. It is characterized in that the pressing surface of the convex portion is deeply sloped continuously or intermittently on the inner peripheral side.

Effect> As the magnetic head is moved toward the outer circumference, the more curved magnetic sheet comes into contact with the deeply sloped inner circumference of the convex portion.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. As shown in the figure,
A groove-like recess 16 is formed in the center of the regulation plate 15, and an inclined surface 1 is formed on the upstream and downstream sides of this groove-like recess [16].
It is 7.18. A convex portion 1 is provided on the outer peripheral side of the regulation plate 15.
9 is provided, and the magnetic sheet can be pressed by this convex portion 19. The outer circumferential side of the convex portion 19 in the direction of movement of the magnetic head is sandwiched as a pressing surface 20 to form a circular arc shape. That is, the pressing surface 20 has an outer circumferential portion 20a having a shallow inclination angle θ and an inner circumferential portion 2 having a deep inclination angle θ2.
0b, and the outer peripheral part 20a and the inner peripheral part 20b are arcuate toward the upstream side and the downstream side. Outer peripheral portion 20a.

There are no particular restrictions on the inclination angle θ, θ and the width W, W of the inner peripheral portion 20b, but as shown in FIGS. 3 and 4, when the magnetic head 4 comes into sliding contact with the magnetic sheet 1 on the inner peripheral side; When the outer peripheral portion 20a and the magnetic sheet 1 are in gentle contact with each other, and the magnetic head 4 is in sliding contact with the magnetic sheet 1 on the outer peripheral side,
It is preferable that the inner circumferential portion 20b and the magnetic sheet 1 come into contact with each other gently. For example, in the case of a video floppy that records video signals, the amount of movement of the magnetic head 4 is about 5 marks,
Note that the width of the groove-shaped recess 16 of the regulating plate 15 is about 4 to 7+ m, θ, z1.9''', θ2:l:11°, W,:0
．． 6 nm, w2: 1.0+n+++. In addition, as shown in FIGS. 3 and 4, the magnetic sheet 1
The pressing surfaces (20a, 20b) of the convex portions 19 do not make smooth contact, but rather create an air film between them, so there are fewer running traces on the back surface of the magnetic sheet 1. Instead, they will almost disappear.

Further, in the above embodiment, the slope of the suppression surface 20 changes intermittently, but the slope is not limited to this and may change continuously. For example, it is preferable to make the pressing surface 20 a curved surface with a radius of curvature R, as in another embodiment shown in FIG. Even when the magnetic sheet is moved, the magnetic sheet is always in gentle contact with the curved suppression surface 20, which is advantageous.

Further, in the above embodiment, the pressing surface 20 is limited to a part of the convex portion 19, but the present invention is not limited to such a configuration, and may be provided over the entire surface.

<Effects of the Invention> As described above in detail based on the embodiments, the regulating plate of the present invention allows the magnetic sheet and the convex portion of the regulating plate to always come into gentle contact even when the magnetic head is moved toward the inner and outer peripheries. So,
A stable head touch can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2(a)
is a sectional view taken along the line ■-■ in FIG. 1, FIG. 2(b) is a sectional view of another embodiment, and FIGS. 3 and 4 are contact states when the magnetic head moves toward the inner and outer peripheries. Figure 5 is an explanatory diagram showing the arrangement of the regulating plate, Figure 6 is a perspective view of a general regulating plate, and Figures 7 and 8 both show the contact between the magnetic sheet and the regulating plate. It is an explanatory diagram showing a state. In the drawing, 1 is a magnetic sheet, 2 is a center core, 3 is a spindle motor, 4 is a magnetic head, 5.15 is a regulating plate, 6.16 is a groove-like recess, and 7.19 is a view from the grooves 6 and 16. The convex portion, 17 and 18 are inclined surfaces, 20 is a suppressing surface, 20a is an outer peripheral portion, and 20b is an inner peripheral portion. Figure 1 Figure 2 Figure 1 Town M5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] A regulating plate facing the magnetic head with a rotating magnetic sheet in between is provided with a convex portion that presses the outer circumferential portion of the magnetic sheet, and the pressing surface of the convex portion is made deeper toward the inner circumferential side in a continuous or intermittent manner. A regulating plate characterized by being inclined.