JPS6149755B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble memory, and in particular, when magnetic bubbles are transferred in one loop in the opposite direction at the position of the loop, the operating margin that exists depending on the transfer direction is This invention relates to a magnetic bubble memory designed to reduce the difference.

When manufacturing a magnetic bubble memory, for example, the first
As shown in the figure, ion implantation is performed on the surface of a magnetic garnet crystal thin film 1 obtained by crystal growth on a single crystal plate in order to control the generation of undesirable hard bubbles. As a result of this ion implantation,
A thin layer 2 whose magnetization direction is horizontal is formed on the surface of the crystalline thin film 1. Then, on this thin layer 2, a plurality of transfer patterns 3 made of permalloy, for example, are formed.
4, and a bias magnetic field H _B is applied perpendicularly to this thin layer 2 to generate magnetic bubbles. A rotating magnetic field is applied to this crystal thin film 1 to drive magnetic bubbles in the direction of arrow A along the transfer patterns 3, 3, . . . and in the direction of the arrow B along the transfer patterns 4, 4, .

When a rotating magnetic field is applied to the crystal thin film 1, the second
As shown by the margin curve B _U in the figure, there is a region where magnetic bubbles exist depending on the magnitude of the rotating magnetic field _HD and the bias magnetic field H _B. Magnetic bubbles do not exist when the bias magnetic field H _B is small, and disappear when it becomes too large, and depending on the rotating magnetic field H _D ,
This exists inside the margin curve B _U in FIG. However, as shown in FIG. 1, due to the existence of the thin layer 2 whose magnetization direction is horizontal, when the magnetic bubble is driven in the directions of arrows A and B along the transfer pattern, when transferring in one direction, It was found that magnetic bubbles may disappear more easily in some directions than in other directions. For example, when a magnetic bubble is driven in the direction of arrow A in FIG. 1, the area where the magnetic bubble exists is determined by the margin curve B _U -a in FIG.
When the magnetic bubble is driven in the direction, the region where the magnetic bubble exists is determined by the margin curve B _U -b, and the margin region becomes small.
If the rotating magnetic field _HD is the same, then if the bias magnetic field H _B becomes a little smaller, it will disappear.
This state is very likely to disappear between transfer patterns.

Therefore, an object of the present invention is to provide a magnetic bubble memory that improves such problems, and for this purpose, the magnetic bubble memory of the present invention has a magnetic bubble generation system that generates magnetic bubbles In a magnetic bubble memory having means and a transfer pattern for transferring magnetic bubbles, the magnetic bubble transfer path is formed by a loop-shaped path having paths in which magnetic bubble transfer directions are different from each other, and
The present invention is characterized in that the pattern period of the transfer pattern on one of the paths is different from the pattern period of the transfer pattern on the other path having a different transfer direction.

Before explaining specific examples of the present invention, the principle of the present invention will be explained based on FIG.

FIG. 4A shows the transfer pattern P and its pattern period λ, and FIG. 4B shows how the margin curve of the magnetic bubble changes as the pattern period λ changes.

When the pattern period of the transfer pattern P shown in FIG. 4A is λ, the margin curve shown in FIG. 2 changes depending on the size of the pattern period λ of the transfer pattern P. Now, when the transfer pattern λ is 7 μm, 8 μm, and 9 μm, and the pattern gaps are all 1 μm, the margin curve becomes the state shown in Figure 4 B, and the larger the transfer pattern λ is, the more the same rotating magnetic field H At _D , the value of the bias magnetic field H _B where the magnetic bubble exists becomes large. In other words, the magnetic bubble becomes difficult to disappear.
Therefore, the principle of the present invention is to increase the shape of the transfer pattern in the transfer direction in which magnetic bubbles are likely to disappear, so that the pattern period becomes large, as shown by the margin curve B _U -b in FIG. For example, the influence due to the presence of the thin layer 2 for suppressing hard bubbles in FIG. 1 can be corrected.

An embodiment of the present invention will be described below with reference to FIG.

FIG. 5A shows the configuration of the magnetic bubble memory, and FIG. 5B shows the state of its minor loop.

In the figure, 5 is a medium loop, 6 is a magnetic bubble generator, 7 is a replicator, 8 is a detector, 9, 9-
0,9-1,...9-n is a minor loop, 10-
0, 10-1, . . . 10-n are transfer gates, 11, 11-0, 11-1, . . . 11-n are corners, and 12, 13 are transfer patterns.

The major loop 5 is for reading or writing data to a large number of minor loops 9-0, 9-1, . . . 9-n that exist as storage areas. When reading data, the magnetic bubble is transferred to the position of the transfer gate by the rotating magnetic field, and the magnetic bubble is transferred onto the medium loop 5 by the transfer gate. The magnetic bubble transferred to the medium loop 5 is divided into two magnetic bubbles by a replicator, and one is transferred on the medium loop 5 as it is. Another magnetic bubble is expanded to the detector 8, increases the resistance change and outputs an electrical signal to the detector 8, and then disappears. Then, the magnetic bubble transferred on the previous major loop 5 is again transferred to the minor loop by the transfer gate and rewritten. When writing new data, the magnetic bubble generator 6 generates and erases new magnetic bubbles, erases old data, sends new data onto the major loop 5, and stores it in the minor loop. It is something to do.

In the present invention, the minor loops 9-0, 9-1, ...9- of the magnetic bubble memory configured in this way
n, the transfer patterns in the transfer pattern rows that are adversely affected by the horizontal magnetic field in the thin layer 2 for suppressing hard bubbles are made larger than those in the rows that are not adversely affected.

For example, as illustrated in _FIG . The transfer pattern 13 is made larger so that its pattern period is larger than that of the transfer pattern 12 in the direction of arrow A.
This causes the magnetic bubble to transfer patterns 13, 13
When the transfer direction changes to the opposite direction at corner 11 via . . . and transfer _patterns 12, 12 . Since the magnetic bubbles are canceled due to the presence of the pattern 13, the conventional drawback that the magnetic bubbles tend to disappear when passing through the transfer pattern row in the arrow B can be improved.

A second embodiment of the present invention will be described based on FIG.

FIG. 6 shows a case where the storage configuration is a single loop configuration, and this single loop 14 is provided with a replicator 7, and the presence or absence of a magnetic bubble is detected by a detector 8. The magnetic bubble on this single loop 14 is generated by the magnetic bubble generator 6.
It is subject to extinction control. When a magnetic bubble transfers a single loop having such a shape, for example, a loop area 14-1 in which the magnetic bubble moves toward the left, and a loop area 1 in which the magnetic bubble moves toward the right.
4-2, one of the loop areas will be adversely affected by the presence of the thin layer 2 for hard bubble suppression, so in such a case, the area affected by the adverse effect, for example, the loop area 14- By configuring the transfer pattern No. 1 with a transfer pattern having a larger pattern period than the transfer pattern of the loop area 14-2, the adverse effect can be removed.

In the above case, an example was explained in which the influence of a transverse magnetic field in a thin layer for suppressing hard bubbles is improved, but the same problem occurs even when a hold magnetic field is applied. That is, the transfer of magnetic bubbles is stopped when the magnetic bubble memory is not accessed. When stopping, it must be stably stopped in a certain direction, so a static holding magnetic field is applied in the lateral direction for this purpose. This hold magnetic field influences the margin curve, and there are transfer directions in which the margin becomes large and in other transfer directions in which the margin worsens and becomes small.

For example, as shown in FIG.
5, 15..., transfer patterns 16, 16..., corners 17, 17, etc. When applying the hold magnetic field H _h in the direction of the arrow shown in the figure, the transfer patterns 15, 15 in the direction of arrow A'
. . . is not adversely affected by the hold magnetic field H _h , but transfer patterns 16, 16 . use something This increases the margin area and improves the drawback that magnetic bubbles disappear between the transfer patterns 16, 16.

In each of the above examples, the transfer pattern is of a half-disk type, but the transfer pattern is not limited to this, and the same applies to an asymmetrical chevron pattern as shown in FIG. 8 or a pattern similar thereto.

After all, according to the present invention, it is possible to improve the adverse effects of the transverse magnetic field on the transfer path of the magnetic bubbles, and effectively prevent the involuntary disappearance of the magnetic bubbles. In particular, when increasing the bias magnetic field to make magnetic bubbles smaller and reducing the transfer pattern to improve bit density, it is only necessary to increase the size of the transfer pattern on the side that is adversely affected, without increasing the transfer pattern of the entire loop. , very effective. For example, as a magnetic bubble 1.5μm to 2.0μm
When a diameter of m is used, the smaller pattern period may be 7 μm to 8 μm, and the larger pattern period may be approximately 9 μm to 10 μm.

[Brief explanation of the drawing]

Figure 1 shows a conventional magnetic bubble memory;
Fig. 3 is an explanatory diagram of its operating state, Fig. 4 is an explanatory diagram of its operating characteristics when the transfer pattern and its pattern period change, and Fig. 5 A is a circuit diagram of the magnetic bubble memory of the present invention. Figure 6 shows the main part of the configuration of one embodiment of the magnetic bubble memory of the present invention.
The figure is another circuit diagram of the magnetic bubble memory of the present invention, FIG. 7 is a block diagram of main parts of another embodiment of the magnetic bubble memory of the present invention, and FIG. 8 is a block diagram of still another main part of the present invention. be. In the figure, 1 is a crystal thin film, 2 is a thin layer, 3 and 4 are transfer patterns, 5 is a major loop, 6 is a magnetic bubble generator, 7 is a replicator, 8 is a detector, 9, 9-
0,9-1,...9-n is a minor loop, 10-
0, 10-1, ... 10-n are transfer gates, 11, 11-0, 11-1, ... 11-n are corners, 12, 13 are transfer patterns, 14 is a single loop, 15, 16 are In the transfer pattern, 17 indicates each corner.

Claims (1)

[Claims] 1. In a magnetic bubble memory having a magnetic bubble generating means for generating magnetic bubbles and a transfer pattern for transferring magnetic bubbles, the magnetic bubble transfer path is formed by a loop-shaped path having paths in which magnetic bubble transfer directions are different from each other, and A magnetic bubble memory characterized in that the pattern period of the transfer pattern on one of the paths is different from the pattern period of the transfer pattern on the other path having a different transfer direction.