JPS59172191A - Magnetic bubble transferring path - Google Patents

Abstract

PURPOSE:To obtain a sufficient bias magnetic field margin by triangular wave driving by obliquely setting the direction of the gap between basic patterns to a magnetic bubble transferring direction. CONSTITUTION:The direction Q of gaps (g) between each pattern 2 adjacently arranged is obliquely set to a magnetic bubble transferring direction P. When the oblique angle is designated by theta, a phase at which a rotary magnetic field 1 becomes minimum and another phase at which a magnetic bubble crosses the gap section (g) can be shifted by theta'. When the obliqud angle is set in a range of 5 deg.-30 deg., a sufficiently large bias magnetic field margin DELTAHB can be obtained. By obliquely setting the direction of the gaps between the basic patterns to the magnetic bubble transferring direction in this way, a sufficiently large bias magnetic field margin can be obtained by triangular wave driving even when the arranging cycle of the basic pattern is reduced.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a magnetic bubble transfer path.

[Background of the invention]

In recent years, the permalloy method has mainly been put into practical use as a magnetic bubble transfer path. This is a method of transferring magnetic bubbles by magnetizing a batten formed by etching a permalloy thin film with an externally applied magnetic field that rotates within the batten plane.The present invention is directed to a transfer path using this method. It is related to.

FIGS. 1(a) and 1(b) are enlarged plan views of essential parts showing an example of a permalloy magnetic bubble transfer path. In the figure, when the external rotating magnetic field l rotates counterclockwise, the magnetic bubbles are transferred from right to left in the direction of arrow P.

Then, when the rotating magnetic field l rotates once, the magnetic bubble is transferred 18 periods of the basic pattern 2. Here, in the same figure (a) K
The basic pattern 2 shown is an asymmetrical chevron batten, shown in the same figure (b
) are called half-disc slams, and both are batans that have been widely used in recent years.

These batons constitute a magnetic bubble transfer path 3 in which the direction Q of the gap 2 portion between the basic battens 2 is perpendicular to the magnetic bubble transfer direction P.

However, the magnetic bubble transfer path 3 with the above configuration,
The magnetic bubble transfer characteristics of basic pattern 2 decrease as the batten arrangement period λ decreases, and when the locus of external rotating magnetic field 1 is square as shown in the figure rather than circular or diagonal, the bias magnetic field margin decreases. There was a problem that the number decreased. Here, when the external rotating magnetic field l is circular, sine wave driving is used.

The hexagonal shape is called trapezoidal wave drive, and the square shape is called triangular wave drive.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned problems, and its purpose is to provide a magnetic field that can provide a sufficient bias magnetic field margin with triangular wave drive even if the arrangement period λ of the basic pattern is reduced. The purpose is to provide a bubble transfer path.

[Summary of the invention]

In order to achieve this object, the present invention makes the direction of the gap between basic patterns oblique to the magnetic puzzle transfer direction.

In other words, the reason why the bias magnetic field margin of a basic pattern with a reduced pattern arrangement period λ decreases in the case of triangular wave driving is considered to be as follows.

That is, in FIG. 2, (a) is a sine wave drive.

Rotating magnetic field vector for trapezoidal wave drive and triangular wave drive) (
This is a comparison of the trajectories of H. As shown in Figure (a), the characteristic of triangular wave drive is that when the magnitude of the rotating magnetic field vector HR is in the 45° direction, it becomes the minimum, and the magnitude is the same for a sine wave and a trapezoidal wave. On the other hand, Fig. 21(b) shows that the magnetic bubble is reduced to 1/v'2''.
This is a diagram showing the relationship between the position of the magnetic bubble on the transfer circuit and the direction of the rotating magnetic field l when data is transferred at KHz "-200K) iz. According to the figure, the position of the magnetic bubble B is in the direction of the rotating magnetic field l. The phase is delayed in the range of 20'' to 40° with respect to the direction. That is, when the directions of the rotating magnetic field l shown in Figure (a) are 00°, 90°, and 270°, magnetic bubble B is delayed by 20° as shown in Figure (b), and magnetic bubble B1 is delayed by 110', respectively. Magnetic bubble B! The magnetic bubble B3 is delayed by 1310''. Among these, the phase is delayed the most when it crosses the gear 212 portion of basic pattern 2, and as shown by the magnetic bubble B3, it is delayed by 40''aIi. This gear 212 determines the bias magnetic field margin.
It's time to cross departments. The strength of the rotating magnetic field l when the magnetic bubble crosses the gap g, which determines the bias magnetic field margin, should be increased, because in the case of triangular wave driving, on the contrary, there is a phase shift of about 40'. It ends up being close to a small value. This caused a decrease in the bias magnetic field margin.

Therefore, the present invention attempts to shift the phase in which the rotating magnetic field Ha is minimized by triangular wave driving so that the phase in which the magnetic bubble crosses the gear 212 portion does not overlap.

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings.

The third @ is an enlarged plan view of the main part showing an embodiment of the magnetic bubble transfer path according to the present invention, and FIG.
b) is a magnetic bubble transfer path in which the basic pattern 2 is a half-disk pattern. These figures are characterized in that the direction Q of the gap g between adjacent basic patterns 2 is oblique to the magnetic bubble transfer direction P. In such a configuration, if the oblique angle is set to θ, the rotational magnetic field l is at its minimum phase and the magnetic bubble is aligned with the gear 21.
The phase across the two parts can be shifted by θ.

Figure 4 shows the experimental results of the bias magnetic field margin width ΔHn when varying the oblique angle θ.
From the same figure, set the oblique angle θ to 50S-3 so that qt+ is smooth.
By setting within the range of 0.06, it was possible to obtain a sufficiently large bias field margin ΔHB.

In addition, in the above-mentioned embodiment, a case was explained in which an asymmetrical chevron pattern and a nine-fold disk pattern were used as the basic pattern, but the present invention is not limited to this, and similar or modified patterns of the above-mentioned patterns are used. Of course, the same effect as described above can be obtained even if a pattern is used.

〔Effect of the invention〕

As explained above, according to the present invention, by making the direction of the gap between the basic patterns oblique to the magnetic bubble transfer direction, even if the arrangement period of the basic pattern is reduced, a sufficiently large bias can be applied by triangular wave driving. This has an extremely excellent effect of providing a magnetic field margin.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are enlarged plan views of main parts showing an example of a conventional magnetic bubble transfer path, and FIGS. 2(a) and (b)
3(a) and 3(b) are enlarged plan views of essential parts showing an example of the magnetic bubble transfer path according to the present invention, and FIG. 4 is a diagram for explaining the problems of the conventional magnetic bubble transfer path. FIG. 3 is a diagram showing the effect of the magnetic bubble transfer path according to the invention. 1... Rotating magnetic field, 2... Basic slam, 3...
・Magnetic bubble transfer path. 7- Condolence 1 anti

Claims (1)

[Claims] 1. A magnetic bubble transfer path that transfers magnetic bubbles by arranging a plurality of basic batons with a certain gap between them,
A magnetic bubble transfer path characterized in that the direction of the gap between the basic batons is oblique to the transfer direction of magnetic bubbles. 2. The magnetic bubble transfer path according to claim 1, wherein the oblique angle is set in a range H of 5° to 30°.