JPS6323809Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a double-sided magnetic disk device that records or reproduces information signals using both the upper and lower principal surfaces of a flexible magnetic disk.

In a floppy disk device, the gap surface of the head that contacts the disk is mirror-finished to ensure stable contact between the disk and the head. Therefore, especially when the disk is used to a certain extent and its surface becomes smooth, and the head surface and the disk become familiar with each other, the head comes into close contact with the disk. Then, when the disk is rotated, the head comes into contact with the disk and slides away from the disk, and the upper carriage of the double-sided floppy disk device resonates and may generate squeal. The upper head carriage is generally formed as a rotatable arm, and this arm is given a biasing force in the direction that adheres the upper head to the disk. If this arm is formed of a relatively soft synthetic resin such as ABS, there is an internal loss, so there is almost no resonance due to the vibration of the magnetic head. Therefore, there is almost no squeal. However, if the upper carriage is made from a highly rigid material such as polyphenylene sulfide (PPS) resin in order to achieve carriage dimensional precision or to improve physical properties, it becomes more likely to produce squeal due to resonance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible magnetic disk device that can eliminate or reduce noise caused by vibration of the arm supporting the upper head.

To achieve the above object, the present invention includes a rotational drive device for rotating a double-sided flexible magnetic disk, a head support base movable in the radial direction of the disk, and a head support base that is movable in the radial direction of the disk. a lower magnetic head mounted on the head support, an upper magnetic head that faces the lower magnetic head and contacts the upper surface of the disk, and supports the upper magnetic head and works together with the head support. a support arm that is movable in a radial direction of the disk; a spring that applies a biasing force to the support arm in a direction that presses the upper magnetic head against the disk; and an elastic body disposed on the support arm; The present invention relates to a magnetic disk device including a rigid body disposed on the elastic body.

According to the present invention, by disposing the rigid body on the head support arm via the elastic body, the vibration of the support arm causes the system consisting of the elastic body and the rigid body to vibrate, and this system generates energy. is consumed, and the support arm is suppressed from squealing due to the resonance phenomenon.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

In the double-sided floppy disk device according to this embodiment, a flexible disk 1 is rotated by a rotary drive device 2, an upper magnetic head 3 is brought into sliding contact with the upper surface of the disk, and a lower magnetic head 4 is brought into sliding contact with the lower surface of the disk. The device is configured to perform recording or playback by The lower magnetic head 4 is attached to a lower carriage or head support 6 via a relatively thick disc-shaped gimbal spring plate 5. The upper magnetic head 3 is attached to an upper carriage or head support arm 8 via a relatively thin disc-shaped gimbal spring plate 7. Arms 9 and 10 extend from the center of the upper and lower spring plates 5 and 7 to provide a fulcrum for gimbal support.

A leaf spring 11 is fixed to the head support arm 8, and one end of the leaf spring 11 is attached to one end of the head support base 6 with screws. The leaf spring 11 is formed to apply a biasing force to the arm 8 in a direction that presses the upper head 3 against the disk 1, that is, in a counterclockwise direction. The support arm 8 rotates clockwise against the bias of the leaf spring 11 when the disk 1 is attached or detached.
During head loading, the arm 8 rotates counterclockwise due to the bias of the spring 11, and the head 3 comes into contact with the disk 1.

12 is an elastic body made of neoprene rubber;
It is fixed at two locations on the upper surface of the support arm 8.
13 is a shield plate made of permalloy plate,
It has rigidity and is fixed onto the elastic body 12.
This shield plate 13 has a mass smaller than that of the support arm 8, and has a U-shaped cross section in this embodiment. 13b.

A guide rod 14 guides the head support 6 in the radial direction of the disk. The head support 6 is moved in the radial direction of the disk by a stepping motor (not shown).

The lower head support stand 6 and the upper head support arm 8 are made of polyphenylene sulfide (PPS) resin. this
PPS resin has high hardness and low elongation, so high mechanical precision can be obtained.

With the configuration as described above, since the head 3 has a mirror finish, a phenomenon occurs in which it comes into close contact with the disk 1, and even if the disk 1 is rotated, a stick-slip condition occurs, and the support arm 8 vibrates. The vibration system consisting of the elastic body 12 and the rigid shield plate 13 resonates, and the vibration of this system consumes the energy of the vibration of the head support arm 8 system.
The resonance phenomenon of the head support arm 8 system is suppressed,
Squealing is prevented.

As is clear from the above, in this embodiment, since the shield plate 13 is used to prevent squealing, the squealing can be prevented very easily.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified. For example, a configuration may be adopted in which the elastic bodies 12 are arranged at four locations. Further, the shield plate 13 may not have a U-shaped cross section, but may be a flat plate. Further, the shield plate 13 may be made of a silicon steel plate other than permalloy, or a composite plate of permalloy and aluminum. Further, if a shield is not required, a rigid body such as a synthetic resin having greater rigidity than the elastic body 12 may be used. Further, the bias of the support arm 8 may be provided by a coil spring, a torsion spring, or the like. Of course, it is also applicable to the case where the lower head 4 is not supported by gimbals.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of a floppy disk device according to an embodiment of the present invention, FIG. 2 is a plan view of the head portion of FIG. 1, and FIG. 3 is a part of the head portion of FIG. 2. FIG. 4 is a left side view of FIG. 3. In the symbols used in the drawings, 1 is a disk, 2 is a rotary drive device, 3 is an upper magnetic head, 4 is a lower magnetic head, 6 is a head support base, and 8 is a rotary drive device.
1 is a support arm, 12 is an elastic body, and 13 is a shield plate.

Claims (1)

[Claims for Utility Model Registration] (1) A rotary drive device for rotating a double-sided flexible magnetic disk; a head support base movable in the radial direction of the disk; a lower magnetic head mounted on the head supporter, an upper magnetic head that faces the lower magnetic head and contacts the upper surface of the disk, and supports the upper magnetic head and is attached to the head supporter. a support arm that is movable in the radial direction of the disk; a spring that applies a biasing force to the support arm in a direction that presses the upper magnetic head against the disk; an elastic body disposed on the support arm; A magnetic disk device comprising: a rigid body disposed on the elastic body; (2) Utility model registration claim 1, wherein the elastic body is rubber and the rigid body is a shield metal plate.
The magnetic disk device described in Section 1.