JPS5816541B2 - Recording or reproducing device using flexible sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic sheet device that uses a flexible magnetic roller and is intended to prevent the magnetic sheet from sticking due to dew condensation. In a magnetic sheet device using a magnetic sheet, when the magnetic sheet stops rotating, the magnetic sheet hangs down and comes into close contact with the lower plate that covers the magnetic sheet, so if the lower plate surface becomes dewy. The magnetic sheet stuck to the lower plate surface, making it impossible to start up.

At this time, if the magnetic sheet is forcibly started by a motor with a strong starting torque, the magnetic sheet may be scratched or wrinkled, and the magnetic sheet device may become unusable.

In order to compensate for these shortcomings, conventional methods have been used to make the magnetic sheet device a sealed structure and either seal dry air or provide a desiccant inside the magnetic sheet device, but it is possible to maintain the sealing function for a long period of time. It is very difficult to carry out the process, and it also increases the cost.Also, there are drawbacks such as the need for dry air sealing equipment when repairing the magnetic sheet device. In view of this, it is an object of the present invention to provide a magnetic sheet device equipped with means for preventing the magnetic sheet from sticking due to dew condensation without causing any increase in cost.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a sectional view of a conventional magnetic sheet device.

The motor 10 is fixed to the lower case 11.

A seat fixture 14 is fixed to a motor shaft 13 of the motor 10.

A flexible magnetic sheet 15 is attached to the seat fixture 14.
is installed.

The upper back plate 16 is fixed to the lower case 11, and the magnetic sheet 1 is attached to the back plate 16 and the lower case 11.
This forms a rotating space 11 of No. 5.

The magnetic head 18 is fixed to the back plate 16 and protrudes from the surface 16-1 of the back plate toward the rotation space 17 so as to face the magnetic sheet 15.

The periphery of the magnetic head 18 is sealed with adhesive or the like.

At the center of the back plate 16 is a lower filter frame 1.
9 is fixed, and the upper filter frame 20 has a filter 21 and a filter 2 between it and the lower filter frame 19.
2. The filter 21 and the filter 23, which are sandwiched between the filter 23 and fixed to the lower filter frame 19 to form the filter unit, are fine-mesh filters that essentially serve as a filter, and are indicated by arrows in the figure. This is to remove dirt, dust, etc. from the air that flows in from the direction.

The filter 22 is a coarse filter that forms an air flow path rather than a substantial filter.

The lower filter frame 19 has an inlet 19-1 for keeping the air flow rate constant.

The printed board 24 that constitutes the servo circuit of the motor 10 and the output amplifier circuit is connected to pillars 25, 25' and pillars 26, 26'.
It is pinned in place.

Pillar. 26.26' is fixed to the lower case 11, column 2
5.25' is fixed to the cover 27 and constitutes a magnetic sheet device.

The naori bar 27 does not have a sealed structure. Figure 2 shows the cover 27 and back cover in Figure 1.

FIG. 3 is a top view showing the structure of the lower case 11 when the rate 16 and the magnetic sheet 15 are removed.

As is clear from the figure, the lower case 11 is formed with, for example, twelve radial grooves 11-1, which are formed approximately equally, and an outer circumferential groove 11-2 connecting these grooves at the outer periphery.

Furthermore, a through hole 11-3 is bored at the bottom of the outer circumferential groove 11-2 at a position that is not in contact with the radial groove 11-1, and the air flowing through the filter unit in the center of the back plate 16 is passed through this hole. More leaks out.

In the radial groove 11-1. In order to prevent the lower plate surface 11-4 which has been divided and polished from sticking to the sheet 15 due to static electricity or the like, the lower plate surface 11-4 is processed into a relatively finely roughened surface by, for example, T-honing.

In such a device, the magnetic sheet 1 is moved by the motor 10.
When the magnetic sheet 5 rotates, the gas in the vicinity of the magnetic sheet 15 is rotated by the magnetic sheet 15 due to its viscosity, and flows with components in the circumferential direction and radial direction of the magnetic sheet due to the centrifugal force.

The airflow generated by the rotation of the magnetic sheet 15 flows through the filters 21, 22, and 23 located at the center of the back plate 16 as shown by the arrows in FIG. 1, and flows between the magnetic sheet 15 and the upper plate 16. flows in the circumferential direction of the sheet, enters the outer circumferential groove 11-2 of the lower case 11, and a part of it flows through the hole 11-3 into the lower case 11.
Flow out of the stream.

On the other hand, the air near the lower side of the magnetic sheet 15 flows outward due to the rotation of the magnetic sheet 15 as shown by the arrow in FIG. Enter and return to near the center of the magnetic sheet along the groove.

Further, the air that has flowed between the magnetic sheet 15 and the lower case surface 11-4 flows again along the magnetic sheet surface toward the outer periphery of the magnetic sheet.

The structure of the conventional magnetic sheet device has been described above, but
It is highly unlikely that such a magnetic sheet device will form condensation due to changes in the environment in which it is installed, such as when it is filled with hot and humid air and is gradually cooled down. This is the case, for example, when high-temperature, high-humidity air flows into the cooled magnetic sheet device.

If the magnetic sheet device is exposed to condensation in this way, condensation may occur on the plate surface 11-4 of the lower case 11 when the magnetic sheet device is stopped.
The lowered magnetic sheet is placed on the plate surface 1 as shown in Figure 3.
1-4 caused sticking, making the magnetic sheet device unusable.

Furthermore, it has been proposed in Japanese Utility Model Application No. 49-38212 to provide a protrusion on the lower plate surface of the magnetic sheet. There is a risk that the air flow between the magnetic sheets 15 and 4 may be disturbed and the rotation of the magnetic sheet 15 may become unstable.

In addition, in view of the fact that it is difficult to prevent sticking due to dew condensation with the protrusions that do not have the above-mentioned impact,
An object of the present invention is to provide a magnetic sheet device that can sufficiently prevent the magnetic sheet 15 from sticking due to dew condensation without disturbing airflow.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view of the embodiment of the present invention, and FIG. 5 is a lower plate surface 11 of the lower case 11 when the cover 27, back plate 16, and magnetic sheet 15 of the embodiment shown in FIG. 4 are removed. It is a top view which shows the structure of the sticking prevention groove|channel 11-5 which is the principal part of this invention in -4.

Note that the same functional parts as those of the conventional magnetic sheet device shown in FIGS. 1, 2, and 3 are indicated by the same reference numerals.

The difference between the embodiment of the present invention shown in FIGS. 4 and 5 compared to the conventional magnetic sheet device shown in FIGS. 1 and 2 is that the lower case 11 as shown in FIGS. Lower plate surface 1
3, that is, the magnetic sheet 15 is tilted at the point where the concentric groove 11-5 is provided in 1-4, and the lower plate surface 11
-4, the area of the lower plate surface 11-4 in contact with the magnetic sheet is smaller than in the conventional magnetic sheet device due to the above-mentioned concentric grooves 11-5, and the adhesion force is extremely low.

Furthermore, because of the concentric grooves 11-5, air can easily flow into the underside of the magnetic sheet 15 that is in close contact with the device at the time of startup, making it possible to start the device easily.

Further, since the grooves 11-5 are concentric grooves, the direction of the airflow is significantly different from the direction of the airflow caused by the rotation of the magnetic sheet 150 as shown by the arrow in FIG. 5, and the airflow is not disturbed in any way.

Incidentally, the outer diameter of the magnetic sheet 15 of the embodiment according to the present invention is 110 mm, the thickness is 30 μm, and the lower plate) 11
-4 has a concentric groove width of L8 mm, a groove depth of 2 mm, and a groove interval of 2.5 mm.

As a result, there was no sticking of the magnetic sheet 15 due to dew condensation under any normally conceivable environmental changes.

Moreover, no disturbance in the airflow due to the grooves is observed, and the rotational state of the sheet can be stable.

In addition, in the embodiment, the groove shape related to the main part of the present invention was made concentric circles, but the present invention can be implemented even if the groove is a spiral shape that does not disturb the airflow caused by 150 rotations of the magnetic sheet. There is nothing wrong with that.

Further, in the embodiments of the present invention, the cross-sectional shape of the groove is rectangular, but the present invention may be implemented even if the cross-sectional shape is V-shaped, U-shaped, or semicircular.

Furthermore, since the lower case 11 in the embodiment of the present invention can be formed by die-casting or molding, the increase in cost of the magnetic sheet device by implementing the present invention is minimal, making it extremely useful in practice. There is

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional magnetic sheet device, Fig. 2 is a top view showing the structure of the lower case in Fig. 1, and Fig. 3 is a side view of a conventional magnetic sheet device. FIG. 4 is a side sectional view of the magnetic sheet device according to the present invention, and FIG. 5 is a top view of the lower plate surface of the main part of the present invention. be. 11... Lower case, 11-1... Groove, 11-2... Outer groove, 11-3...
Through hole, 11-4...Lower plate surface, 11-
5... Groove, 13... Motor shaft, 15... Magnetic sheet, 16... Back plate.

Claims (1)

[Claims] 1. A rotating means for rotating a flexible sheet-like recording medium, a head for recording or reproducing information on the recording medium,
In a recording or reproducing device using a flexible sheet having upper and lower plates arranged across the recording medium to form a stable air flow along the recording medium when the recording medium is rotated. , reducing the contact area between the recording medium and the lower plate when the recording medium is stopped, and not affecting the air flow generated between the recording medium and the lower plate when the recording medium rotates. A recording or reproducing device using a flexible sheet, characterized in that a groove extending along the circumferential direction of the recording medium is formed on the lower plate surface. 2. A recording or reproducing device using a flexible sheet according to claim 1, wherein the grooves are arranged concentrically around the rotation axis of the recording medium. 3. The recording or reproducing apparatus using a flexible gear tracker according to claim 1, wherein the groove is arranged in a spiral shape around the rotation axis of the recording medium.