JPH0363152B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a method for measuring the flying characteristics of a floating slider of a magnetic disk that has a magnetic layer on a nonmagnetic substrate and performs high-density recording using the floating slider of a magnetic head.

[Prior art and its problems]

To measure the levitation characteristics of conventional magnetic disks,
An acoustic emission sensor (hereinafter referred to as AE sensor) is attached to the magnetic head arm, and the rotation speed of the disk is gradually increased to detect the effect of the airflow generated by the disk's contact with the floating slider attached to the tip or rotation of the disk. This was done by reading the output signal from the AE sensor based on the vibration of the arm with an effective value voltmeter or the like. However, the flying characteristics obtained in this manner can only be evaluated for a portion of the disk corresponding to the width of the floating slider, and therefore have the disadvantage that the entire disk surface cannot be evaluated.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for measuring flying characteristics that can eliminate the above-mentioned drawbacks and evaluate the flying characteristics of a slider over the entire surface of a magnetic disk.

[Key points of the invention]

According to the present invention, the output of the AE sensor attached to the magnetic head arm is measured by moving the floating slider of the magnetic head over the entire radius of the disk while rotating the magnetic disk at a low rotational speed, and then rotating the magnetic disk. By repeating the same measurement operation in which the disk is rotated at higher rotational speeds, it becomes possible to evaluate the flying characteristics of the entire disk surface, thereby achieving the above objective.

[Embodiments of the invention]

FIG. 1 shows an apparatus for an embodiment of the invention, in which a magnetic disk 1 to be measured is mounted on a rotating shaft 7. FIG. An AE sensor 4 is attached to an arm 3 that supports a floating slider 2 of a magnetic head that is placed opposite to the surface of the disk 1. The AE sensor 4 is connected to a signal processing device 6. The arm 3 is fixed to a movable stage 5, and the arrow 8
The disk 1 can be moved in the radial direction as shown in FIG. Using such a device, the disk 1 is rotated at a low speed by the rotating shaft 7. At this time, the movable stage 5 is moved in the direction of the arrow 8 over the entire radius of the disk, the vibration of the floating slider 2 is detected by the AE sensor 4 via the arm 3, and the signal processing device 6 performs signal processing. Further increase the rotation speed and perform the same operation. By determining the relationship between the magnitude of the output signal of the AE sensor 4 and the flying height in advance using a glass disk, etc., you can gradually increase the rotation speed and perform AE.
By repeating the measurement of the sensor output, the flying characteristics of the entire surface of the disk 1 can be measured. At that time, the floating slider 2 becomes a low flying object when the number of rotations exceeds a certain number, and when the arm 3 is moved in the radial direction of the disk, if there is a protrusion on the surface of the disk 1 that exceeds the flying height, the floating slider 2 will come into contact with it, so the protrusion can also be detected. This can be done on the entire disk surface.

[Effects of the Invention] The present invention makes it possible to measure the flying characteristics of the entire disk surface by moving a floating slider in the radial direction of the disk while the magnetic disk is rotating at the same rotation speed. By moving the floating slider in the radial direction at a rotational speed at which the floating slider is at a low flying speed, there is an effect that protrusions on the entire disk surface can be detected at the same time.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an apparatus for one embodiment of the invention. 1: Magnetic disk, 2: Floating slider, 3: Arm, 4: AE sensor, 5: Movable stage, 6:
AE sensor signal processing device.

Claims (1)

[Claims] 1 While rotating the magnetic disk at a low rotational speed, the floating slider of the magnetic head is moved over the entire radius of the disk to measure the output of the acoustic emission sensor attached to the magnetic head arm, and then the magnetic disk is sequentially moved. A method for measuring slider flying characteristics of a magnetic disk, which is characterized by repeating a similar measurement operation of rotating at a higher rotation speed.