JPS6087420A - Azimuth measurement medium of magnetic head - Google Patents

Abstract

PURPOSE:To attain measurement even for an azimuth produced by a parallel shift of a magnetic head and to ensure the accurate measurement of azimuths, by recording the azimuth measurement information of the magnetic head at least on a track at the inner circumferential side and a track at the outer circumferential side among plural tracks. CONSTITUTION:The azimuth information is recorded on a track 8 near the most outer circumference and a track 68 near the most inner circumference of an azimuth measurement medium. This medium is loaded to a floppy disk device for which an azimuth should be measured, and a magnetic head is shifted to the track 8 to measure an azimuth theta1 there. Then the magnetic head is shifted to the track 68 to measure an azimuth theta2 there. Then theta1not equal to theta2 is satisfied a position shift (x) due to a parallel shift of the magnetic head is not 0. In addition, the azimuth measurement information is recorded when necessary on an intermediate track between tracks of the inner and outer circumferential sides. Thus the accuracy is improved for measurement of azimuths.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a medium for measuring magnetic field azimuth such as a floppy disk device, and particularly to a medium for measuring magnetic field azimuth such as a floppy disk device. This invention relates to a medium for measuring β-resistance and notonoazimuth.

fb) Technology V! In an ideal case where the recording magnetization on the image medium is sinusoidal (wavelength λ) and oriented in the length direction of the trunk, as shown in Fig. is parallel, and the direction of the gear knob is 90-0 degrees or opposite to the width direction of the truck)
■The output from the 3rd student's research station produces the following output [0 loss f(θ).

(8=oat Mika"7jT'Syhi'cL+"'
io) Here, ν■ is the core width of the magnetic node, and λ is the recording wavelength of magnetic recording.

In a magnetic recording device, ideally the direction of magnetization recorded on the medium and the angle formed by the gap between the magnetic head are at right angles. However, especially in floppy disk devices, disk puncture devices, etc. that require high media compatibility, an angular error (azimuth) with respect to the right angle actually occurs due to assembly errors of the magnetic, throat, and J in each device. Therefore, when the device is shipped, it must be inspected to see if this azimuth is within the specified range. This azimuth can be determined by reproducing the azimuth measurement information recorded on the azimuth measurement medium by the device to be inspected, and thereby knowing the amplitude of the output waveform.

Here, the azimuth information recording method will be explained with reference to FIG. Azimuth information is composed of a plurality of burst signals. The reproduced output of this burst signal has a sinusoidal waveform. And in advance, -ra, 1-θ/,
Record four burst signals Δ, B, C, and D at the same wavelength λ by four magnetic −\sotho° with azimuth of −”/, 'θ2 (1θj −, /, 1) I'll keep it.

FIG. 2 shows the envelopes (representing output amplitudes) of the output waveforms of these four burst signals. The medium on which these burst signals are recorded is inserted into a device for measuring unmass, and the reproduced output waveform is observed with an oscillator 1-1 scope or the like. At this time, the reproduction output is azimuth 1011 and 5, which is roughly set in the medium magnetization direction when azimuth information is recorded.
This produces an azimuth loss f(θ) (referred to as a burst) corresponding to the difference in azimuth from 0 that the magnetic node of the device has individually. Therefore, suppose Burst 8 and Hearth IB are equal.

becomes. Therefore, since marrow + Q"Q + -0, θ = (0, -9,) / U, which sums up the azimuth force that this device has individually. Suppose that Birth I-C and Noku-st B force, etc. (O, -9□)/2- Burst C> Burst D Rotation > (8z-e+) / 2.Therefore, if we change the standard value of )'7 to °3-.

&s=('9--e+)/'1.
(or equivalent) in LJ, azimuth is 1 each (c)
If it was recorded with a magnetic head, a +++ should be set, when the azimuth of the device is θ - 111" - the hands - 82 - 3 y 0, - 02 3 yo. Therefore, burst A and burst B match. Then, it can be seen that the azimuth of the device is θ--15゛.

πWθ determines the azimuth loss as seen from the first equation
FIG. 3 shows the relationship between /λ and the above azimuth loss (dB). As can be seen from this figure, the change in azimuth loss is large where the value of πWθ/λ is large, and the change is small where the value of πWθ/λ is small. Since the value of azimuth θ is minute, in order to easily measure it, it is better to measure it in the range of πWθ/λ, where the azimuth loss changes greatly even with a minute change in θ. In a normal rotating recording medium, the recording wavelength is small on the inner circumference side and large on the outer circumference side, so in a conventional azimuth measurement medium, azimuth information is recorded only on the inner circumference side and the azimuth is measured in the region where the value of πWθ/λ is large. Taking measurements.

However, as shown in FIG. 4, there are two conceivable reasons why the gear knob 2 of the magnetic nozzle 1 is tilted with respect to the magnetization direction 3 of the medium 4 with respect to the half-i direction (0 is the center) of the medium 4.

One is the assembly error when removing the magnetic throat. One more thing: magnetic field - there is a shift due to the parallel movement of the 21st month. That is, when the magnetic head (2) moves in parallel in the direction of the arrow y and comes to the position of the magnetic head 1'', the angle formed by the gap 2° and the magnetization direction 3'' of the medium 4 becomes θ2. If the angle formed with the magnetization direction 3 is 07, then the direction of parallel movement of magnetism 1 is half of the medium (if it is installed offset by X from the \ direction, θ, NO!L).・).

Therefore, even if the azimuth is measured on the inner track using a conventional azimuth measurement medium, the azimuth will be different if the magnetic head moves parallel to the outer track.

(d) Object of the Invention The object of the present invention is to provide an azimuth measurement medium that can also measure azimuth due to parallel movement of a head by recording constant azimuth information on the outer circumferential side and intermediate tracks. There is one for each.

(el) The structure of the invention and the object of the invention are a rotating magnetic recording medium having one concentric trunk.

Azimuth measurement of a magnetic hexagon, characterized in that information for azimuth measurement of a magnetic field is recorded in at least one track on the inner circumference side and one track on the outer circumference side among the plurality of tracks. This is accomplished by providing a pair of media.

(f) Embodiment of the Invention An embodiment of the present invention will be described below by taking a Novy disk device as an example.

The azimuth information (i[i recording method jif=
-: The outermost circumference of the azimuth measurement medium at J (; the trunk near J (1 rack 8) and the track near the innermost circumference (toshinoku 6;
)) Record the azimuth information.

This azimuth measuring medium is loaded into a floppy disk device whose azimuth is to be measured, a magnetic head is placed thereon, and the azimuth 0Σ at this position is measured.

When the positional deviation X due to parallel movement of the magnetic head is not zero, n1\r~.

It should be noted that if necessary, the unmass measurement information is recorded on a track intermediate between the track on the inner circumference side and the track on the outer circumference side, thereby making it possible to measure the azimuth more accurately.

Note that the present invention has similar effects not only on floppy disk devices but also on other compatible devices (disk puncture devices, etc.).

+g+Effects of the Invention As described above, according to the present invention, it is possible to measure azimuth that changes η due to positional deviation due to parallel movement of the throat due to magnetism, making it possible to measure azimuth more accurately. .

[Brief explanation of drawings]

Figure 1 is a diagram for explaining azimuth. Fig. 2 is a diagram for explaining the conventional azimuth measurement information recording method, and Fig. 3 shows azimuth information loss and θ/A l/, /
A graph showing the relationship, Figure 4 is an engraving of a drawing to explain the change in azimuth due to parallel movement of the magnetic head (content 1 remains unchanged). 1. Figure 4. Procedure amendment (method) 1932? +1λ IIノ011 1 thing f1 table 3Illi positive -(-ru old

Claims (1)

[Scope of Claim] A rotating magnetic recording medium having a plurality of concentric trunks. An azimuth of a magnetic head characterized in that, among the plurality of tracks, at least one trunk on the inner circumferential side and one trunk on the outer circumferential side are recorded with information for measuring the azimuth of magnetic '7'. Measuring medium.