JPS6356887A - Magnetic disk device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a contact start method using a floating head.
Regarding a stop (hereinafter abbreviated as rcssJ) type hard disk drive, more specifically, a magnetic disk drive that forcibly floats the head by blowing gas near the front tapered part of the head slider when the disk starts rotating. It is related to.

[Prior Art] A C8S type magnetic disk device using a floating head is conventionally known. In this type of magnetic disk drive, the floating head is initially pressed against a predetermined area on the outer peripheral side of the magnetic disk by a spring force and remains stationary. Next, when the disk begins to rotate, the air that moves as the disk rotates due to its viscosity is forced into the tapered section in front of the head slider, and the force generated by the compressed air flow causes the head to float. The magnetic disk is stabilized at a position balanced with the spring force, and information can be written to or read from the magnetic disk.

[Problems to be Solved by the Invention] In the C3S type magnetic disk device, the head is in close contact with the disk when the disk is stopped, and there is a problem in that an attraction phenomenon occurs. Particularly in recent years, with the demand for high-density recording, the flying height of a floating head has become smaller and smaller, and accordingly, the surface precision of the disk surface and head flying surface has been processed to be extremely high. For this reason, the degree of adsorption is also very strong. Furthermore, the longer the period when the head is stationary, the stronger the degree of adsorption becomes. For these reasons, the disk cannot start its rotation normally, and problems such as head crashes are more likely to occur.

Further, even when the disk starts to rotate, the dynamic pressure generated is low until the disk reaches a certain rotational speed, so the head remains in contact with the disk, which poses a problem of wear of the head and disk.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, to enable the head to quickly float when the disk starts rotating, to allow the disk to start rotating normally, and to further reduce wear on the head and disk. The objective is to provide a magnetic disk device that can

[Means for Solving the Problems] The present invention, which can achieve the above objects, provides a CSSSS type electromagnetic disk device using a floating head, in which the front position of the floating head in the head standby area on the outer circumference side of the disk is fixed. This is a magnetic disk drive in which a gas blowing nozzle is installed in the disk, and when the disk starts rotating, gas is sprayed near the front tapered portion of the head slider to force the head to float.

The pressurized gas may be supplied before the disk starts rotating, or at the same time as the disk starts rotating. The gas supply is continued until the disk reaches a predetermined rotational speed and the head can fly a predetermined height without continuing the gas supply. Furthermore, it is desirable to supply gas from the nozzle in the same way not only at the time of starting but also when the floating head returns to its standby area at the time of stopping to keep the disk floating until it stops rotating.

[Operation] When the rotation speed is low and the floating blade acting on the head is low, such as when the disk starts rotating, gas is ejected from the nozzle and sent to the vicinity of the front tapered portion of the head slider to force the head to float. This allows the disk to remain floating even at low rotational speeds.

Therefore, even if the head and disk are attracted to each other before the disk rotation starts, the disk rotation start operation can be performed without the risk of trouble such as a head crash.

Furthermore, at the time of starting, for example, dynamic pressure equivalent to the dynamic pressure that would conventionally be generated when the disk reaches a predetermined rotational speed is generated at a low rotational speed, and the head landing operation is performed with the head sufficiently floating. , almost no wear occurs between the head and the disk. The same holds true when stopping, and the head can be slowly brought into contact with the magnetic disk whose rotation has stopped.

[Embodiment] FIG. 1 is an explanatory diagram showing an embodiment of a magnetic disk device according to the present invention. The magnetic disk 12 attached to the spindle hub 10 is connected to a spindle motor (not shown).
It can be rotated in the direction of arrow A by. floating head 14
is attached to the tip of the support spring 16, and the support spring 16
The proximal end of the magnetic disk 12 is attached to the helad arm 18 so that a head positioning mechanism (not shown) can perform track selection operations in the radial direction of the magnetic disk 12.

A feature of the present invention is that a gas blowing nozzle 20 for blowing gas in front of the head 14 is provided in a head standby area on the outer peripheral side of the magnetic disk 12. This nozzle 20 is connected to a compressed air generator 24 through an air supply pipe 22, and the compressed air generator 24 is configured to send out or stop the compressed air, or control the amount of air being sent out, in response to a signal from a control unit 26.

Since this magnetic disk device is a C8S type, the floating head 14 is pressed against the disk surface by the spring force of the support spring 16 in the head standby area on the outer circumference side of the disk while the disk rotation is stopped. The gas jet nozzle 20 is fixed at a fixed position slightly in front of the head during standby.

Immediately before the rotation of the disk starts, compressed air is supplied from the compressed air generator 24 through the air supply pipe 22 in response to a signal from the control unit 26, and as shown in FIG. (as indicated by arrow B). This generates an air flow between the head 14 and the disk 12, and the head 14 flies over the floating blade (indicated by arrow C) against the spring force of the support spring 16. When the rotational speed of the magnetic disk 12 reaches a certain level,
As in the conventional case, the head 14 flies up to a certain height due to the air flow accompanying the rotation of the disk 12, and in that state, the control unit 2
6, the operation of the compressed air generator 24 is stopped and the nozzle 2
Stop supplying compressed air from 0. Of course, the control unit 26 may control the amount of compressed air blown from the nozzle 20 as the rotational speed of the magnetic disk 12 increases.

After that, the head positioning mechanism performs the trunk selection operation of the floating head 14 with respect to the magnetic disk 12 as in the conventional case.

When stopping the rotation of the magnetic disk 12, compressed air may be similarly supplied from the nozzle 20. &f1 When the disk 12 is stopped, the floating head 14 returns to the head waiting area 8g on the outer circumferential side of the disk. In this state, the compressed air from the compressed air generator 24 is supplied to the nozzle 2 in the same way as when starting.
The head 14 is sprayed from zero toward the floating head 14 to increase the flying edge of the head 14 and maintain the floating state so that the head does not contact the disk even if the rotation of the magnetic disk 12 slows down. After the magnetic disk 12 has completely stopped, the blowing of compressed air from the nozzle 20 is gradually reduced, and the floating head 14 is slowly brought into contact with the magnetic disk 12.

By supplying compressed air from the nozzle when starting and stopping in this way, an airflow is forcibly created between the head and the disk, reducing or eliminating the attraction force between the head and the disk before the disk starts rotating. and prevent various troubles from occurring. Even when the magnetic 5-hood slides against the magnetic disk, the surface pressure can be reduced, so deterioration of characteristics due to wear and head crash can be prevented.

The compressed air generator 24 may be provided outside the head disk assembly, but since the air sent out through the air supply pipe 22 needs to be highly clean, it is necessary to take measures such as passing it through a separate filter. Further, the nozzle 20 is structured so that air is evenly supplied to the front tapered portion 14a of the head 14. The control section 26 preferably has a function of starting the compressed air generator 4 prior to the rotation of the disk, and also controlling the amount of air sent out in accordance with the rotational speed of the disk as described above.

[Effects of the Invention] As described above, the present invention provides a gas ejection nozzle at a position in front of the floating head in the head waiting area on the outer circumferential side of the disk,
When the disk starts rotating, gas is sprayed near the front tapered part of the head slider to force the head to float, which prevents various troubles caused by adhesion between the head and the disk. This has extremely excellent effects, such as preventing deterioration of characteristics and occurrence of head crashes due to wear.

The present invention is particularly effective as heads and disks are machined with high surface precision as recording densities increase, and since nozzles, air supply pipes, etc. are fixed at fixed positions, the structure may become complicated. Therefore, there is no risk of hindering miniaturization.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a magnetic disk device according to the present invention, and FIG. 2 is an explanatory diagram showing a flying state of a floating head according to the present invention. 12... Magnetic disk, 14... Floating head, 14
a...Front tapered portion, 16...Support spring, 20...
- Nozzle, 22... Air supply pipe, 24... Compressed air generator, 26... Control unit.

Claims (1)

[Claims] 1. In a contact start/stop type magnetic disk device using a floating head, a gas jet nozzle is installed in front of the floating head in the head standby area on the outer circumference of the disk, and when the disk starts rotating, it is installed in front of the head slider. A magnetic disk device characterized in that a head is forcibly floated by blowing gas near a tapered portion.