JPS61151839A - Eliminating device for surface projection of magnetic disk - Google Patents

Abstract

PURPOSE:To eliminate the projections on a disk surface in a short time and to ensure the free control of the eliminating height, by applying the DC voltage between a vanish head and a recording disk and controlling the floating of the vanish head at a low level to the recording disk by means of the static electricity. CONSTITUTION:When a disk 11 to be vanished is revolved at 3,000rpm by a spindle 12, a vanish head 14 floats up by about 0.3mum. Under such conditions, a switch 17 is turned on to apply the DC voltage between the head 14 and the disk 11. Thus the static electricity is produced between those head 14 and the disk 11. Then the head 14 is sucked by the disk 11. The floating height of the head 14 from the surface of the disk 11 can be controlled by changing the level of said DC voltage. Thus the minute projections on the surface of the disk 11 are shaved off by the head 14 at the height equal to or larger than said controlled height.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device suitable for removing surface projections of a magnetic disk used, for example, in a magnetic disk device.

[Conventional technology]

In order to improve the quality of magnetic disks, minute protrusions on the disk surface are removed during the manufacturing process.

As a method for removing protrusions, a vanishing head for removing protrusions is installed so that it can float above a rotating magnetic disk, and the flying height of the vanish head is lowered by reducing the number of revolutions of the magnetic disk, thereby scraping off minute protrusions on the disk. method is known.

[Problem that the invention seeks to solve]

However, the above-described conventional method for removing protrusions on the disk surface requires a long time to remove the protrusions in order to reduce the number of rotations of the disk, resulting in a problem in that the manufacturing time of the disk increases, impairing mass productivity.

This problem is noticeable in recent high-density magnetic disks that require high surface smoothness. In other words, in a magnetic disk device that enables this high recording density, the magnetic head needs to fly lower than the magnetic disk, and in order to stabilize this low flying height, the disk surface must be made smoother. However, the time required to remove the protrusions is correspondingly longer than that of current magnetic disks.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional situation, it is an object of the present invention to provide a device for removing protrusions on a disk surface, which can remove protrusions on the disk surface in a short time and can freely adjust the removal height. It is.

Means for Solving Problems c] In order to solve the above-mentioned problems, the present invention provides a vanishing head which is provided to be able to float on the surface of a rotating recording disk and which removes minute protrusions on the surface. , comprising means for applying a DC voltage between the vanishing head and the recording disk, and controlling the flying height of the vanishing head with respect to the recording disk to a low level by static electricity generated between the head and the recording disk as a result of this voltage application. This method is characterized by removing minute protrusions on the surface of the disk.

[Effect]

When a DC voltage is applied between the vanish head and the recording disk, static electricity is generated between them, and this force attracts the vanish head, which is floating due to the rotation of the recording disk, toward the disk, increasing its flying height. is set low to scrape off minute protrusions on the disk surface. The height of the protrusion scraped off can be easily controlled by keeping the disk rotation speed constant and changing the magnitude of the DC voltage to change the flying height of the head.

〔Example〕

FIG. 1 is a diagram conceptually showing a magnetic disk surface protrusion removing device to which the present invention is applied. In this figure, 11
is a magnetic disk from which surface protrusions have been removed (hereinafter referred to as a burnished disk), and consists of an aluminum substrate coated with a magnetic recording layer, a lubricating layer, and the like. Reference numeral 12 denotes a conductive spindle that rotates the burnished disk 11 at a specific rotational speed of 30,000,73,600 rpm, and a portion thereof is connected to the negative terminal of a DC power source 13 of 30 to 40V. Further, 14 is a burnish head made of titanium carbide-containing alumina ceramiref (Aft03/T i C), etc., and 15 supports the burnish head 14 so that it can float on the burnished disk 11 and be movable in the radial direction thereof. A gimbal 16 is an arm of a head actuator that moves the gimbal 15. Both the gimbal 15 and the arm 16 are made of a conductive material, and the positive terminal of the DC voltage source 13 is connected to the arm via a switch 17.

Next, the process for removing protrusions on the disk surface having the above configuration will be explained. First, the disc 11 to be burnished is placed on the spindle 12.
When rotated at 3000 rpm, the vanish head 14 flies by about 0.3 μm. In this state, switch 1
7 to apply a DC voltage between the burnish head 14 and the disk 11 to be burnished.

As a result, static electricity is generated between them, attracting them, but in reality, the vanishing head 14 is attracted to the disc 11 to be burnished. Second
The figure shows the relationship between applied voltage and electrostatic force, and the vanish head can be attracted within a range of 0.3 m using the aforementioned DC voltage of 30 to 40 V. Therefore, by varying the magnitude of the DC voltage, the flying height of the vanish head above the disk surface can be adjusted. Based on this, the magnitude of the DC voltage is selected in advance according to the type of disk to be burnished, that is, the required surface smoothness and the initial flying height of the burnish head.

When the flying height of the vanish head 14 is set to a desired height in this manner, the head scrapes away the minute protrusions on the surface of the disc 11 to be burnished by the head.

〔effect〕

As is clear from the above description, the present invention reduces the flying height of the recording disk by changing the DC voltage applied to the disk and the vanish head without reducing the number of revolutions of the recording disk. Since the protrusions on the surface of the recording disk can be burnished while rotating at high speed, the manufacturing time of the disk can be shortened. In addition, since the height of the protrusion to be removed can be adjusted simply by varying the magnitude of the applied voltage, the apparatus can be configured at a lower cost and simpler than the conventional variable rotation speed configuration.

[Brief explanation of drawings]

FIG. 1 is a diagram conceptually showing a magnetic disk surface projection removal device to which the present invention is applied, and FIG. 2 is a diagram showing the relationship between applied DC voltage and electrostatic force. 11: Recording disk to be burnished, 12 Nispindle, 13: DC voltage source, 14: Vanishing head, 15 Nishinpal, Engineering 6: Head actuator arm, 1
7: Switch 17° Figure 1 Figure 2

Claims (1)

[Claims] A vanishing head is provided to be able to float on the surface of a rotating recording disk and removes minute protrusions on the surface, and a means for applying a DC voltage between the vanishing head and the recording disk, and when the voltage is applied, A device for removing surface protrusions on a recording disk, characterized in that the static electricity generated between the head and the recording disk controls the flying height of the vanish head relative to the recording disk to be low to remove minute protrusions on the surface of the disk. .