JPH02294920A - Observing method for head touch - Google Patents

Abstract

PURPOSE:To directly compare and check the recording and reproducing characteristic of a real head with a head touch characteristic by executing image processing to the interference fringe of the real head from the interference fringe between a glass slider and the real head and the interference fringe singly of the glass slider. CONSTITUTION:To a floppy disk 101, a double-face magnetic media sweeping out part 106 and a one-side magnetic media sweeping out part 107, which is adjacent to this part 106, are manufactured. Next, a disk 101 is chucked to a spindle shaft 304 and a mercury lamp 308 is turned on. Then, a glass slider 301 is irradiated with single color light through a filter 309, half mirror 311 and objective lens 310. The interference fringe to be generated by both a fine interval between the glass slider 301 and a floppy disk 303 and the fine interval between a real head 302 and the disk 303 is photographed by a TV camera 312 and picture data are stored in a picture memory 313. Then, the picture processing is executed by a computer 315.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for observing the state of contact between the head of a floppy disk drive and a magnetic medium (hereinafter referred to as head touch).

[Conventional technology]

In recent years, the storage capacity of magnetic storage devices using floppy disks has been increasing, and it is known that head touch has a significant effect on increasing storage capacity. An excellent observation method was also desired for the contact state, so-called hand touch. The head touch observation method conventionally used in this type of storage device is shown in the schematic diagram of the arrangement of the floppy disk and floppy magnetic head used in the conventional head, media touch observation method in Figure 3. To ensure this, the floppy disk 201 is a regular product that has not been subjected to any additional processing such as wiping off the magnetic media, and a glass slider is used for one of the double-sided floppy magnetic hends 204 and 205. As shown in the block diagram of the head and media touch observation method in FIG.
The light generated from the filter is made into monochromatic light by a filter 609,
The monochromatic light is sent to the glass slider 601 through the half mirror 311 and the objective lens 610.
01 and the floppy disk 306 are captured by the TV camera 612 and stored in the image memory 6.
The method of observing the head touch of a floppy disk drive, which is stored in memory in 16 and observed on TV monitor 614, is well known as the optical interference fringe method.

[Problems that the invention helps solve]

However, in this optical interference fringe method, the magnetic media layer is usually coated with magnetic fine particles of cobalt gamma iron oxide and does not allow visible light to pass through. Therefore, only the interference fringes caused by the minute gap between the glass slider 601 and the floppy disk 606 can be observed, and the minute gap between the real head 302 and the floppy disk 306 does not cause interference fringes. From the above, the recording and reproduction electromagnetic conversion characteristics (hereinafter simply referred to as recording and reproduction characteristics) of the actual head 602 are known (but the actual head 3
Since I don't know the head touch characteristics of the 02, there was a problem in that it was difficult to directly compare and examine the recording/playback characteristics and the touch characteristics.

In order to solve the above problem, conventionally, the transparent substrate 206 is exposed except for the magnetic media layer 202 in contact with the double-sided magnetic heads 204 and 205 shown in FIG. 3, and the floppy disk 606 shown in FIG. Attempts have been made to observe interference fringes caused by the tiny contact gap between the actual head 602 and the transparent substrate caused by light incident from the back side of the glass slider 601, but the interference fringes caused by the gap between the glass slider 601 and the transparent substrate are superimposed. Therefore, it was difficult to observe an individual head touch of the real head 602.

The present invention has been made to solve the above problem, and it directly compares the recording and playback characteristics of the actual head with the head touch characteristics.
The purpose of this paper is to provide a head touch observation method for floppy magnetic heads that can be studied.

[Means to solve the problem]

In order to solve the above problems, the present invention uses a glass slider on one side of double-sided magnetic heads that face each other via a floppy disk from which a part of the magnetic media layer has been removed, and a real head on the other side. A method of observing the contact state of the real head with the floppy disk by interference fringes of light incident from the back side, and the method includes superimposed interference fringes of both the glass slider and the real head, and interference fringes of the glass slider alone. It is characterized in that the interference fringes of the actual head are generated by image processing from the difference between the two.

〔Example〕

The head of the floppy magnetic head according to the present invention shown in FIG.
As shown in the schematic diagram of the arrangement of a floppy disk and a floppy magnetic head used in the media touch observation method, a floppy disk 101 is wiped with an organic solvent such as tetrahydrofuran using a double-sided magnetic media wiping section '106, Adjacent to the media wiping unit 106, a single-sided magnetic media wiping unit 107 is fabricated. Next, the floppy disk 101 is mounted on the spindle shaft 604 as shown in the head and media touch observation knob block diagram of the floppy magnetic head in FIG. 3, the mercury lamp 608 is turned on, the filter 609 is 611, monochromatic light is applied to the glass slider 601 through the objective lens 610; glass slider 601
The TV camera 612 captures the interference fringes generated by the minute gap between the floppy disk 606 and the actual connector 602 and the floppy disk 606, and stores the image data in the image memory 616.
Image processing is performed in step 15.

Hereinafter, the specific procedure will be explained along with the flowchart of the head and media touch measuring method of the floppy magnetic head shown in FIG.

As shown in FIG. 1(b), the heads 105 and 104 are moved to the double-sided magnetic media wiping section 106.

Next, the mercury lamp 308 is turned on as shown in FIG.

Interference fringe I after t time from index. of? image memory 6
16. Next, as shown in FIG. 1C, the heads 104 and 105 are moved to the single-sided magnetic media wiping section 107. Interference fringes t time after index■. t is stored in the image memory 616. Interference fringes Ti. ＋、■It
into the computer. ■■ Performs image processing of minus I. Display LQ minus 1 piece on CRT.

When t is changed, the process returns to the beginning, and when t is not changed, the process ends.

As shown in FIG. 4, on the other hand, the recording of the actual head 602,
The reproduction electromagnetic conversion characteristics are determined by the recording and reproduction circuit 60 triggered by the index signal of the index detection circuit 605.
The reproduced waveform from 6 is displayed on an oscilloscope 607.

Note that in FIG. 1(a), the double-sided magnetic media wiping section 106 is formed on the inner circumferential side of the floppy disk 101 with respect to the single-sided magnetic media wiping section 107.
It is also possible that the double-sided magnetic media wiping part is formed on the outer peripheral side of the floppy disk with respect to the single-sided magnetic media wiping part.

Furthermore, in the schematic diagrams of the arrangement of the floppy disk and the magnetic head shown in FIGS. , it is also possible to arrange the real hands 105 on the SO and S] sides, respectively.

Here, the light intensity of interference fringes will be explained in detail. If the intensities of the reflected light from the surface of the glass slider 1040 and the surface of the magnetic media layer 102 with which the glass slider 104 is in contact are denoted by 1o and Il1, respectively, then the light intensity of the interference fringes is 1o and 111, respectively.
is L-(Lo+I+:-1-2I1oIBcosδ+)"
Table of contents.

Here, δ1 is the phase difference due to the optical path difference between the two reflected lights, and δ is the wavelength of monochromatic light d1 is the same as the minute gap between the glass slider and the magnetic media. Assuming that the intensity of the reflected light from the surface of the real head 1050 and the surface of the magnetic media layer 102 with which the real head comes into contact is 120 s 2+, the light intensity 2 of the interference fringe is I2-(I2o+I2, + 2I2oI21COSδ
2) It is expressed as 3A.

Here, δ2 is the phase difference due to the optical path difference between the two reflected lights, and λ is the wavelength of the monochromatic light d2 is the single-sided magnetic Media wiping section 10
When the magnetic head is placed at 7, the light intensity of the interference fringes is 1, as described above. On the other hand, the light intensity ■ of the interference fringes when the magnetic head is placed in the double-sided magnetic media wiping section shown in FIG. :-1-I:+2 I,
I2COSδ).

Here, δ is the phase difference between I1 and I.

Here, assuming that the thickness of the transparent substrate is approximately 80 μm, and that the phase difference δ varies randomly due to variations in the thickness, that is, assuming that they are incoherent, then i=20.

Here, cpsδ represents the temporal and spatial average of cosδ.

Therefore, ■1 (I: + I:)A is found.

From the above, the light intensity (2) of interference fringes caused by the minute gap between the actual head and the magnetic medium can be determined as I2-(I2x: )'.

If (2) is determined according to the above equation, the interference fringes caused by the extremely small difference between the actual head and the magnetic medium will be determined.

〔Effect of the invention〕

As shown in the above detailed explanation, the method for observing the head and media touch of a floppy magnetic head according to the present invention enables the observation of the head touch of the actual head that performs recording and playback, so that it is possible to observe the head touch of the actual head that performs recording and playback. Since the characteristics can be compared and studied directly, it has the effect of facilitating designs such as optimizing the slider shape on the media sliding surface of the actual head and optimizing the carriage mechanism in which the head is mounted. There is.

[Brief explanation of the drawing]

FIGS. 1(a) to (c) are a plan view of a floppy disk and a schematic diagram showing the arrangement of the floppy disk and magnetic head, respectively, showing one embodiment of the present invention, and FIG. 2 is a floppy disk of the present invention. Flowchart diagram showing head and media touch measurement method of magnetic head, Fig. 3(a), (
b) is a plan view of a conventional floppy disk and a schematic diagram showing the arrangement of the floppy disk and magnetic head, and FIG. 4 is a Glock diagram of the head of the floppy magnetic head and a media touch observation system. 101,201,303...Floppy disk 02...Magnetic media layer, 04,204,301...Glass slider, 0
5, 205, 302, old... real hend, 06...
...Double-sided magnetic media wiping section, 07...Single-sided magnetic media wiping section.

Claims (1)

[Claims] A glass slider is used on one side of the double-sided magnetic head facing the floppy disk from which a part of the magnetic media layer has been removed, and a real head is used on the other side. This is a head touch observation method regarding the contact state of the head with the floppy disk, and the difference between the superimposed interference fringes of both the glass slider and the real head and the interference fringe of the glass slider alone is used to determine the difference between the superimposed interference fringes of the glass slider and the real head. A head touch observation method characterized by generating and observing interference fringes through image processing.