JPH0757257A - Apparatus for inspecting magnetic disk - Google Patents

Abstract

PURPOSE:To exactly check projections on a magnetic disk surface by additionally providing the apparatus for detecting and removing the microprojections existing on the magnetic disk surface with a head to be exclusively used for detecting the projections. CONSTITUTION:The magnetic disk 3 is rotated at a high speed by using a spindle 2 in a direction a. While the surface of the disk 3 is floated in its radial direction by a projection removing head 4 at the height lower than the height of a region for assuring the floating of the head from radius r1 to r2 of the region for assuring the floating of the head, the disk is sought once and the high projections are roughly ground off. The head is then sought at the height for assuring the floating from r1 to r2 by the head 9 to be exclusively used for detecting the projections and the position thereof (radius and angle) is stored onto the memory of a computer which is an external apparatus. As a result, the projection components during the removal of the projections hardly stick to the head 9 to be exclusively used for detecting the projections and the projections on the surface of the disk 3 are exactly checked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk inspection apparatus for cutting and removing minute projections on the surface of a magnetic disk by using a head.

[0002]

2. Description of the Related Art In a magnetic disk drive, a magnetic head floats on the surface of a magnetic disk that rotates at a high speed to perform recording / reproduction. However, the flying height of the magnetic head is low as the capacity and density of the magnetic disk drive increase. Therefore, there is a high risk that the rotating magnetic disk comes into contact with the magnetic head to cause a head crash. Some causes of this head crash are caused by minute protrusions existing on the disk surface. Therefore, in order to prevent such an accident and stabilize the flying of the head, it is necessary to remove the protrusion beforehand.

As a method for removing minute projections on the surface of a magnetic disk, there is a detection apparatus using a projection detection / removal head as disclosed in Japanese Patent Laid-Open No. 5-28472. Further, a detection device using a removal head dedicated to rough cutting and a projection detection / removal head is also known.

A conventional magnetic disk inspection apparatus will be described below with reference to FIGS. 3 and 4. FIG. 3 is a plan view of a main part showing an operation range of the magnetic head of the inspection apparatus, and FIG. 4 is a plan view showing an operation of each head with respect to the minute protrusion.

As shown in FIG. 3, a spindle motor 2 is fixed to a base 1, and a magnetic disk 3 is mounted on the rotary shaft of the spindle motor 2. Further, on the base 1, a projection removing head 4 for roughing the surface projections of the magnetic disk 3 and a piezo element 6 (a kind of piezoelectric element) for detecting and removing the minute projections 5 on the surface of the magnetic disk 3 are used as a head core portion. The detection / removal head 7 is attached to the head.

In the above structure, first, the magnetic disk 3
In order to roughen the protrusions on the surface of the magnetic disk 3, the protrusion removing head 4 moves the surface of the magnetic disk 3 from the radius r1 to the radius r2, which is a guaranteed area, to a height h2 lower than the guaranteed height h1. Seek once. Next, the detection / removal head 7 is used to change the radius r1 to r of the surface of the magnetic disk 3.
By seeking up to 2 with a head flying height of h1, a protrusion higher than h1 on the surface of the magnetic disk 3 is detected.

As shown in FIG. 4, when the protrusion 5 is detected with a radius r3, the head / center of the head core centering between the width A around the r3 by the detection / removal head 7 is h3 (h1>h3> h).
The protrusions 5 are removed by reciprocating any number of times in 2).

Then, the detection / removal head 7 is set to the flying height h1 at the position of r3 to check whether or not the protrusion 5 is removed. If the protrusion 5 is detected again, the same operation as above is performed. This operation is repeated until the protrusion 5 is no longer detected.

[0009]

However, in such a conventional apparatus for removing protrusions, since there is no head dedicated to detecting protrusions, one detection / removal head 7 is used to detect and remove protrusions. It was Therefore, protrusion detection
Since the protrusion component (magnetic film and dust in the air) adheres during the removal of the protrusion 5 by the removal / combining head 7, a large amount of the protrusion component adheres to the protrusion detecting / removing head 7, and the protrusion to be actually removed. However, there is a drawback in that a protrusion lower than the above is detected, and accurate protrusion detection cannot be performed.

The present invention solves the above-mentioned conventional problems, and an object thereof is to accurately detect protrusions on the surface of a magnetic disk.

[0011]

In order to achieve the above object, the present invention provides an inspection apparatus for detecting and removing minute projections existing on the surface of a magnetic disk, and a projection for rough cutting the projections on the surface of the magnetic disk. In addition to the removal head and the combined detection / removal head that detects and removes minute protrusions, a protrusion-dedicated head is provided, and each head is moved back and forth in the diametrical direction of the magnetic disk surface to detect and remove protrusions. It is configured to be performed.

[0012]

In the above-described structure, since the present invention is provided with the head exclusively for detecting protrusions on the surface of the magnetic disk, it becomes difficult for the protrusion component during removal of the protrusions to adhere to the head exclusively for protrusion detection, so that the protrusions on the surface of the magnetic disk can be accurately measured. By checking, it becomes possible to accurately remove the minute protrusions on the magnetic disk surface.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same components as those described in the conventional example are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is a plan view of an essential part showing a magnetic head operating range of the inspection apparatus of the present invention, and FIG. 2 shows the operation of each head with respect to a minute protrusion.

1 and 2, the point different from the conventional example is that a projection detecting dedicated head 9 in which a piezo element 8 is attached to the head core is added, and is used together with the conventional detection / removal head 7 and projection removal head 4. Then, the magnetic disk 3 is inspected.

Next, the inspection method of this embodiment will be described. As shown in FIG. 1, first, the magnetic disk 3 is rotated at a high speed in the direction a using the spindle 2 and the projection removing head 4 is used to measure the diameter of the surface of the disk 3. In the direction, the head floating guarantee area of the radius r1 to r2 is floated at a height h2 lower than the head floating guaranteed height h1 and seeks once to perform rough cutting of protrusions higher than h2.

Next, the projection detecting dedicated head 9 is used to move from r1 to r
A protrusion higher than h1 on the surface of the magnetic disk 3 is detected by seeking with a head flying height of h1 up to 2, and the position (radius, angle) is stored in the memory of a computer that is an external control device.

As shown in FIG. 2, when the protrusion 5 is detected at a radius r3, the detection / removal head 7 moves to the position of r3, and the center of the head core moves between the widths A centering on r3 and the flying height h3. (H1>h3> h2), the work of removing the protrusion 5 is performed by performing reciprocal seeks any number of times.

Then, the detection / removal head 7 is set to the flying height h1 at the position r3 to check whether or not the projection 5 has been removed. If the protrusion 5 is detected, the same operation as above is performed, and the protrusion 5 is not detected, or this operation is performed up to a preset maximum number of repetitions. Further, this operation is performed for all protrusions higher than h1 detected from r1 to r2. Furthermore, by using the protrusion detection dedicated head 9 to seek once from the r1 to r2 at the flying height h1, it is checked whether or not the protrusions 5 higher than h1 on the surface of the disk 3 have disappeared, and if the protrusion 5 is detected. (Here, it is assumed that the protrusion 5 is detected again.) The protrusion removal head 4 is moved to the protrusion detection position r3.
Then, the protrusion 5 is removed by reciprocating seeking with the flying height h2 at the center of the head core around the width A around the width r3.

Then, the projection-dedicated head 9 is sought once from the r1 to r2 with the flying height h1 to check whether or not the projections 5 higher than h1 on the surface of the magnetic disk 3 have disappeared. If so, the same operation as described above is repeated until no protrusion is detected.

According to the magnetic disk inspecting apparatus of the present invention, conventionally, one projection detecting / removing head 7 and one projection removing head 4 are used to detect and remove the minute projections 5 on the surface of the magnetic disk 3. Compared to the conventional method, by separately using the protrusion detection dedicated head 9 and the detection / removal head 7, the protrusion component during the protrusion removal is less likely to adhere to the protrusion detection dedicated head 9, and the surface of the magnetic disk 3 is prevented. It is possible to accurately check the protrusions of.

[0022]

As is apparent from the above description, according to the present invention, in the apparatus for detecting and removing the minute protrusions existing on the surface of the magnetic disk, the protrusion detecting dedicated head is added, and the detection / removal head and the protrusion By using this together with the removal head, it becomes difficult for the projection component during projection removal to adhere to the projection detection dedicated head, and it becomes possible to accurately check the projections on the magnetic disk surface.

[Brief description of drawings]

FIG. 1 is a plan view showing a magnetic head operation range of a magnetic disk inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing the operation of each head with respect to the minute protrusion.

FIG. 3 is a plan view showing a magnetic head operation range of a conventional magnetic disk inspection device.

FIG. 4 is a plan view showing the operation of each head with respect to the minute protrusion.

[Explanation of symbols]

 3 magnetic disk 4 projection removal head 5 projection 7 detection / removal head 9 projection detection head

Claims (1)

[Claims] 1. A projection removing head for rough cutting of projections on a magnetic disk surface in an inspection device for detecting and removing fine projections existing on the surface of a magnetic disk,
In addition to a detection / removal head that detects and removes minute protrusions, a protrusion-dedicated head is provided, and each head reciprocally seeks in the diameter direction of the magnetic disk surface,
Magnetic disk inspection device that detects protrusions and removes them by cutting.