JPS5868222A - Alignment adjusting method and alignment disk - Google Patents

Abstract

PURPOSE:To detect and correct the direction and extent of the shifting of a head accurately, by recording signals of three slightly different kind of frequencies on an optional track of a magnetic disk and on its both sides at equal intervals, and then reproducing them. CONSTITUTION:In an area A with track width 4, a signal of frequency f0 is recorded centering on an optional track 3 on a magnetic disk. In areas B and C formed on both sides to width nearly equal to the width 4, signals of slightly different frequencies f0+DELTAf1 and f0+DELTAf2 (f1not equal to f2) are recorded. This magnetic disk is reproduced by a reproducing head having width nearly equal to the width 4. When the reproducing head is positioned accurately at the track 3, a constant level is obtained by the signal f0, but if it is displaced to the area B or C, beats f1 or f2 are generated and the extent of them varies with the distance of the displacement. Thus, the direction and extent of the displacement are detected to facilitate correction to the correct position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for adjusting the alignment of an electromagnetic transducer (hereinafter referred to as "magnetic head") in a magnetic recording device such as a Fi70 disk drive, and an alignment disk suitable for implementing the method. L1) In detail, there is a method for adjusting the alignment of a magnetic head by writing a specific signal I on an arbitrary track and regenerating the specific signal, and a method for adjusting the alignment of a magnetic head by writing a specific signal I on an arbitrary track, and a method for adjusting the alignment of a magnetic head by writing a specific signal I on an arbitrary track, and a method for adjusting the alignment of a magnetic head by writing a specific signal I on an arbitrary track, and a method for adjusting the alignment of a papermaking magnetic head by regenerating the specific signal I. This is a story about improving the recording method.

When adjusting the alignment of the magnetic head in a magnetic recording device such as a 7W:1 disk drive (hereinafter simply referred to as "device J"), a specific signal recorded on a recording medium such as a 7W:1 disk is reproduced. Then, the reproduced waveform as shown in the first WJ is observed with a syntalscope over the entire circumference of the target track.1 This method detects the first scrap period of the recording medium.
The alignment of the magnetic head is known from the ratio of the output voltage vA = vl of the reproduced signal generated in
As shown in 11g, v, -v, and no reproduction signals appear, but
m* If the alignment of the magnetic head of the target device has an error in the radial direction, <v, , >V as shown in FIG.
, , (or V, , < V, □).

However, in the case where the recording medium is flexible, such as a 70-inch disc, there may be problems such as uneven film thickness on the recording medium, shadows on the jacket housing the recording medium, etc. Due to vibrations of the recording medium caused by this, it is difficult to obtain a constant reproduction signal output at any track position, and even when continuous writing at a constant frequency is performed, as shown in curve 2 shown in 3. There were many cases where the reproduced signal on one round was uneven. In this case, in the process of recording and reproducing, although the alignment is originally correct as shown in FIG. 1, the song 1lill (
(as shown by the dashed line), the alignment is displayed as if it were talking about it), and on the other hand, the alignment may be displayed as if it were correct even though the alignment was originally imposed. There was a serious flaw in his inability to make proper judgments.

Himi Akisha This was done in view of the above circumstances, and its purpose is to eliminate the above-mentioned drawbacks in the alignment adjustment of the L1 conventional magnetic head, and to prevent alignment accuracy from being hindered by the characteristics of the alignment disk. An object of the present invention is to provide an alignment adjustment method that allows alignment adjustment to be performed easily without any problems, and an alignment disk suitable for implementing the method.

The gist of the present invention is that, in order to measure and adjust the alignment of the magnetic head of a magnetic recording device, an arbitrary frequency f is placed at a predetermined track position on a recording medium with a width approximately equivalent to the core width of the magnetic head. Perform signal recording and further vA) Adjacent to the rack and on both sides thereof, said frequency titt, and slightly different frequencies #f, +△f,, f0+△1. (However, △fl+
At the point where signals are recorded at Δr, ), the frequency Δf is generated due to the interference of the reproduced waveforms obtained when these signals are reproduced.

The alignment of the magnetic head of the device under test is determined from the magnitude of Δf.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 4 shows a signal pattern recorded on an alignment disk according to an embodiment of the present invention. Track width approximately equal to the core width of the head, arbitrary frequency @f0, arbitrary length l□
Write the signal (indicated by zone A),
However, the frequency %r. The frequencies f0+Δf1 y f@+ are adjacent to both sides in the width direction of the track recorded in
4. Signals I&F are read in at fs (represented by zone B and zone 0, respectively).0 Note that T indicates the same period in the circumferential direction of the rack (as described above).

As an example, a disk rotating at 36 Qrpm has 500
When writing with KH2, assuming that the output wave shadow is close to a sine wave, to-500 has a horse, Δf, -50HzSΔf
, --100 towns, each zone B, 0
I will elaborate on it. When reproducing the recorded signals from a disk on which such signals have been recorded using a magnetic head, when the magnetic head straddles zone A and zone B of the recorded signals on the disk, the beat waveform of 50H8 will also be reproduced from the zone zone. and zone C, 100n
Beat waveform 2 is observed. Here, beat waveform and playback l11
It refers to the undulation of the F envelope.

On the other hand, when the amplitude of the beat waveform is expressed as the ratio of the peak value V□ and the bottom value Vmi□, it is determined from the ratio of the magnetic head occupied in each zone as shown in Fig. 6 (4). That is, the displacement of the magnetic head in the tractor width direction is the amplitude m of the beat waveform.
It can be seen that it changes linearly with mtn. From this and the frequency of the beat waveform, the direction of the displacement of the magnetic head can be determined, so when the beat waveform as shown in FIG. 6 (6) is observed, That Bi! Vma of the amplitude of the waveform
Using z e Vaim and the period T0, the displacement of the magnetic head can be measured - and conversely, the alignment of the magnetic head can be determined with respect to the disk on which the reference signal has been written. .

This will be explained in detail below.

In the following explanation, it is assumed that the recording pattern shown in FIG. 4 is to be reproduced from an alignment ψ disk on which the recording pattern is written.

(υFigure 6 (A) shows a situation where the track width center line of the magnetic head (its position is indicated by 6) is aligned with the predetermined center line 3 of the alignment disk. be.

In this case, the magnetic head passes only through the zone, and the output signal waveform is displayed as shown in FIG. 6).

■If the magnetic head slightly deviates from the center line 3 toward the zone B side, as shown by 6& in FIG. 7(4),
As shown in FIG. 7, the beat envelope waveform of the reproduced signal shows the beat envelope waveform lm of the writing frequency of zone 1 and zone. This beat envelope waveform One person's peak value Vll & bottom value Vain
From the ratio, the displacement of the magnetic head 5& is also determined by the period T0
The direction of the displacement is measured from .

(■ When the magnetic head slightly deviates from the center line 3 toward the zone C side as shown at 613 in FIG. 7(4), the beat envelope waveform of the reproduced signal changes to the zone C side as shown in FIG. The beat empel loop waveform IB is obtained for the zone and zone.From this, the displacement of the magnetic head 5b and its direction are measured in the same way as in the above case.

As is clear from the above embodiment, by observing the envelope waveform of the reproduction output of the recording signal, the deviation of the magnetic head from the track width center line 3 can be easily determined.

, but it is common knowledge that this frequency can be selected arbitrarily. Δf0. The range of Δf is f,
It is desirable that the amount is about 0.01 to 0.2%. Further, the write signal may be recorded over the entire circumference of a predetermined track on the recording medium, or may be recorded only on a part of the entire circumference or at several locations.Furthermore, in the above embodiment, the magnetic Zones A, B, and 0 were set up adjacent to each other so that extremely small positional changes in the head could be detected using the ton beat waveform. According to the present invention, in order to adjust the alignment of the magnetic head of a magnetic recording device, the magnetic field is placed at a predetermined track position on the recording medium. A boiling signal is recorded at an arbitrary frequency with a radius approximately the same as the core width of the head, and a frequency f0+△f slightly different from the frequency F/fo is recorded on both sides adjacent to the track.
1. fo+△r, (however, △f0+△r,) signals &!
Since we decided to do this in green, it is now possible to easily measure the misalignment of the magnetic head! It is a stutter that has an erotic effect. Furthermore, by supplying a recording medium on which the above-mentioned signals are pre-recorded as an alignment disk, it is highly effective that general users can easily carry out the above-mentioned measurements.

[Brief explanation of drawings]

Figure 1, Figure 2, and Figure 3 are diagrams showing the playback signal waveforms of conventional alignment disks. ), (BI
Diagrams showing the relative relationship between the write signal of the Fi main button and the magnetic head position, Figures 6 (A), (6), and Figures 7 (4) to O
&l! FIG. 3 is a diagram showing a specific example of a magnetic head position shift and a reproduced signal waveform. 1.1 Envelope waveform of IB+ playback signal, 2 Envelope waveform by constant frequency continuous writing, 3:
) Rack center line 4') Rack width, 5'
e 5 a r 5 b; Magnetic head position, M: Zone As B: G > BSO: Zone OS'I' +
Disco period, TLs T: period of the beat envelope waveform. Figure 1 Figure 2 Figure 3 Zone A Zone B Zone C1 Figure 4 11 Figure 5 C or 1 (X) 50 0
50 100 percentage track width direction deviation Cl5) 1

Claims (1)

[Claims] (1) Alignment of a magnetic head in a magnetic recording device in which the alignment of the magnetic head is adjusted by writing a specific signal onto an arbitrary track of a disk-shaped magnetic recording medium and reproducing the specific signal. In the adjustment method, a specific signal to be written on the disk of the recording medium is written at an arbitrary frequency 'Ikf at the center position of an arbitrary disk of the recording medium with a track width that is approximately the same as the core radiation of the magnetic head. , a second signal written at a frequency f0+Δf, which is slightly different from the frequency f, at one of the two radial positions tangent to the first signal, and a second signal written at a frequency f0+Δf, which is slightly different from the frequency f, I11 from the third signal written at the other position adjacent to the first signal at a frequency f6+Δf, which is slightly different from the frequency f0 and f0+Δf8.
! An alignment adjustment method characterized by: ■In an alignment disk for adjusting the alignment of a magnetic head in a magnetic recording device that adjusts the alignment of a magnetic head by reproducing a specific signal written on an arbitrary track, the specific signal is used to adjust the alignment of the magnetic head. A first signal written on the disk at f0, and a second signal written at one of the two radial positions tangent to the first signal at a frequency f0+Δf8 slightly different from the frequency f0; The frequency f and f0+Δf are located at the other position adjacent to the first signal. and a third signal written at a frequency f, +Δf, which is slightly different from either of the above.