JPS58199488A - Magnetic bubble storage element - Google Patents

Abstract

PURPOSE:To realize large capacity and high performance by using the 1st stretcher made of ''Permalloy'' patterns, the 2nd stretcher made of conductor patterns arranged under them, and a magnetic bubble element consisting of a detector and a degausser. CONSTITUTION:Current pulses are fed to a stretcher 4 so that a magnetic bubble transferred through a transfer line 1 reaches the 1st stretcher 21 made of chevron patterns to start stretching there by the gradient of a rotating magnetic field and then reaches the center part of the 2nd hairpin stretcher 4 to decrease vertical bias magnetic field. Then, the magnetic bubber stretches at a stroke and is transferred to the detector 3, where it is detected. Then, the bubble is transferred through a stretcher 23 and when it reaches the center part of the degausser 5, a current pulse is conducted to cease the bubble. Consequently, many detectors can be arranged at optional positions and a detector area is reduced in area.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in magnetic bubble storage elements, particularly in the detector region.

Important functional parts that are components of a magnetic bubble storage element include a magnifier and a detector. The detector used to read stored information usually uses a magnetoresistive element that detects the leakage magnetic field from a magnetic bubble, but a single circular magnetic bubble cannot generate enough magnetic field to detect it. Since this is not possible, a magnifying device is required to enlarge the magnetic bubble to a length several hundred times the diameter before detection. Since the detection output increases in proportion to the magnifier of the magnetic puzzle, it is possible to obtain a practical detection output by providing the magnifier. After detection, the expanded magnetic bubble is usually rejected outside the guardrail.

Various types of batten structures have been proposed for magnetic bubble expanders, but currently the so-called multi-stage chevron expander, which essentially consists of a chevron-shaped permalloy pattern, is most widely used. When expanding a magnetic bubble using a multi-stage chevron expander, it is not possible to expand the bubble hundreds of times all at once due to domain wall mobility, so a method of sequential expansion as shown in FIG. 1 is used. Figure 1 is a configuration diagram of a conventional magnifier and detector (hereinafter referred to as the detector area) of a magnetic bubble storage element, in which 1 is a transfer path 2 is a chevron expander, 3 is a detector, and 4 is a guardrail. It shows.

However, as can be seen from Figure 1, many chevron patterns 2 are required to expand the magnetic bubble to the length of the detector, which increases the area occupied by the detector area within the element, and also increases the area occupied by the detector area within the element. Since the guardrail 4 is required to reject the magnetic bubbles, the position of the detector region within the element is restricted, and there is a drawback that it must be placed around the element. Therefore, it is not possible to provide a large number of detector regions within one element, and the number of detector regions is usually one to two, or at most four. As memory elements have become much simpler, architecture and air technology has also diversified. For example, in order to achieve high-speed readout, it is necessary to install a large number of detectors in one element and at arbitrary positions. must be made smaller. If this can be realized, the degree of freedom in design will be high and the performance deterioration that accompanies an increase in TB capacity can be prevented.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic bubble memory element that has a small unit area and a detector area that does not require a guardrail.

The present invention features at least a magnetic bubble expander.

In a magnetic bubble storage element comprising a detector and an extinguisher, the expander includes a first magnet made of a permalloy pattern.
a magnifying device and a second magnifying device formed of a conductive pattern laid under the first magnifying device, and the detector detects the magnetic bubbles magnified by the first and second magnifying devices. and the extinguisher is a magnetic bubble storage element that is an extinguisher made of a conductive button laid under the first magnifying device that extinguishes the magnetic bubble detected by the detector. . Further, the second expander and the extinguisher may be made of the same conductive button.

The reason why the expander of the conventional configuration shown in FIG. 1 has to occupy a large area and expand sequentially is that there is a limit to the mobility of the magnetic bubble domain wall. The maximum domain wall movement speed in garnet material with a magnetic bubble diameter of around 1 to 2 μm is 30 to 40 m/
If a sufficient magnetic field gradient is given, it can be expanded to the required length within several microseconds, that is, within one period of a rotating magnetic field with a normally used magnetic frequency of about 100 KHz. However, since the maximum domain wall velocity cannot be obtained only with the magnetic field gradient induced by the chevron expander, it is necessary to adopt a method of successively expanding the magnetic field over several tens of periods of the rotating magnetic field.

The present invention provides a first expander made of a permalloy pattern, such as a chevron expander, and a second expander made of a conductive material in the lower layer of this expander, and a current pulse is passed through the second expander to generate a sufficient amount of electricity. This is achieved by applying a magnetic field gradient to the magnetic bubble to rapidly expand the bubble, and after detection, passing a current pulse through an extinguisher made of a conductor placed under the first expander to extinguish the magnetic bubble.

5- The present invention will be explained in detail below using the drawings. FIG. 2 is a block diagram showing a detector area of a first embodiment of a magnetic bubble storage element according to the present invention. When the magnetic bubble that has been transferred through the transfer path 1 in the right direction of FIG. 2 at a transfer period of 10 μsec reaches the first expander 21 of the 50-stage chevron made of a permalloy pattern, the magnetic field gradient of the chevron pattern is induced by the rotating magnetic field. It starts to expand a little. This magnetic bubble forms a hairpin-shaped second expansion made of a conductive button.
□When reaching the center of the large organ 4, a width of 3 μsec is applied to the second enlarger 4 so that the vertical bias magnetic field of the core becomes smaller.
energize the current pulse. Due to this current pulse, the magnetic bubble that had begun to partially expand is immediately moved to the first expander 21.
It will now be expanded to a longer period. Once expanded, the magnetic bubble remains expanded to its full size even after the current pulse is removed.
It is transmitted through the subsequent chevron expander 22 and reaches the detector 3 where it is detected. The detected magnetic bubble is transferred to the subsequent chevron expander 23, and when it reaches the center of the hairpin-shaped annihilator 5 made of a conductive button, it annihilates so that the vertical bias magnetic field at the core becomes larger. A current pulse with a width of 3 μsec is applied to the device 5. The expanding magnetic bubble shrinks and disappears due to this current pulse. In this way, conventionally it took several tens of cycles from entering the magnifier to passing through the detector and being rejected, but according to this embodiment, it only takes three cycles, which greatly reduces the area of the detector area. As a result, guardrails are no longer required.

FIG. 3 is a block diagram showing the detector area of a second embodiment of the magnetic bubble storage element according to the present invention. The difference from the first embodiment shown in FIG. 2 is that the second expander and annihilator are the same.
The detector 3 is constructed of a conductive pattern 6 of At the same time that the magnetic bubble is expanded to cover all the parts of the first expander 21, it is detected by the detector 3, and immediately after the detection, a current pulse is applied to the conductive pattern 6 in the opposite direction to that at the time of expansion, and the bubble is extinguished. .

FIG. 4 shows the timing within the cycle of the functional units related to this series of operations. FIG. 4 shows the rotating magnetic field, detection output waveform, detection strobe pulse, and conductor pattern 6 in the second embodiment.
The temporal relationship of current pulses flowing through Vc is shown in a, b, c and d, respectively, in this order. According to this embodiment, the required transfer cycle from entering the enlarger to passing through the detector and being rejected is only one cycle, and the area of the detector region is further reduced than in the first embodiment.

As explained above, according to the present invention, the area of the detector region can be significantly reduced, and guardrails are no longer required in the detector region, making it possible to arrange many detectors at arbitrary positions within the element. It has become. As a result, there is a high degree of freedom in designing the layout of large-capacity, high-performance magnetic bubble memory elements.
It is industrially beneficial.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a detector area used in a conventional magnetic bubble memory element, and FIGS. FIG. 4 is a block diagram of a detector area in a magnetic bubble storage element according to a second embodiment of the present invention, and is a diagram showing a temporal relationship of driving states of a magnetic bubble storage element according to a second embodiment of the present invention. In the figure, l... transfer path, 2, 21, 2
2゜23...first magnifier, 3...detector, 4...second magnifier, 5...extinguisher, 6... ...It is a conductor pattern. 9- Roll 3 Figure 4 Figure 418-

Claims (2)

[Claims] (1) In a magnetic bubble storage element comprising at least a magnetic bubble expander, a detector, and an extinguisher, the expander is laid under a first expander made of a permalloin pattern and a layer below the first expander. a second magnifying device made of a conductive button, the detector is a detector for detecting the magnetic bubble magnified by the first and second magnifying devices, and the annihilator is a detector for detecting the magnetic bubble magnified by the first and second magnifying devices; 1. A magnetic bubble memory element comprising: an extinguisher made of a conductive batten laid under the first expander for extinguishing magnetic bubbles detected by the device. (2) The second enlarger and the extinguisher are made of the same conductive button (
1) The magnetic bubble memory element described in item 1).