JPS5911987B2 - magnetic bubble generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble generator used in a magnetic bubble memory device, and more particularly to a nucleation type magnetic bubble generator comprising a loop-shaped conductor pattern.
This is intended to prevent malfunctions when magnetic bubbles occur and expand the operating margin.

First, the structure and operation of a conventional magnetic bubble generator consisting of a hairpin-shaped conductor pattern will be explained based on FIG. P
1, P2, P3, . . . are transfer patterns made of permalloy or the like, and are arranged in a row to form a transfer path. The leading pattern P0 is shaped like a pickaxe and also serves as a generator of magnetic bubbles (hereinafter referred to as "bubbles"). C is a conductor pattern made of Al-Cu, etc., and a hairpin-shaped loop (conductor pattern) R
have. The innermost part 1 of the gap G of this hairpin-shaped conductor pattern R is arranged so as to overlap with the top end of the pickaxe pattern P1. It is assumed that a bias magnetic field HB10 for making bubbles stably exist is applied upward perpendicular to the plane of the paper, and a rotating magnetic field HR for transferring bubbles rotates counterclockwise. Rotating magnetic field H
When R faces in the direction indicated by the hatched area 2, the top ends of each transfer pattern P, P2... are magnetized to ゛+゛, but in this section, the conductor 15' turns C in the direction of the arrow. When a pulsed current Ig flows, a pulsed magnetic field is generated in the gap G of the hairpin-shaped conductor pattern R in a direction that weakens the bias magnetic field HB, thereby creating a bubble B, and the top of the pickax pattern P. It is absorbed by 20. The bubbles B thus generated are transferred to the left side of the figure along the transfer patterns P, P2, P3, . . . as the rotating magnetic field HR rotates, and are sent to the storage section. By the way, the bias magnetic field HB is weakened within the gap G by the current 25Ig applied to the conductor pattern C, so that the generated bubbles B extend along the gap G in a stripe shape.

However, as the pulse current Ig increases and the bias magnetic field decreases accordingly, the bubble elongation increases.
When the pulse current Ig becomes too low and the pulse current Ig is cut off, the striped bubbles B become extremely unstable and are likely to split and generate excessive bubbles, which may destroy the written information. The current threshold that causes malfunction when such a bubble occurs decreases as the temperature of the 35 magnetic bubble chip increases, and as a result, the operating temperature range of the magnetic bubble element is limited. It is an object of the present invention to reliably prevent such malfunctions when bubbles are generated, that is, the generation of excessive bubbles, and to expand the operating margin of a magnetic bubble generator.

To this end, the present invention double-surrounds the nucleation region of a magnetic bubble with a conductor pattern, in which a nucleation current flows in the nucleation direction in the inner conductor pattern, and in the outer conductor pattern, a nucleation current flows in the nucleation direction. The wiring is configured so that a current flows in the opposite direction to the creation current. Next, an embodiment of the magnetic bubble generator according to the present invention will be described.

2 to 4 are diagrams showing different embodiments of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In FIG. 2, loop-shaped conductor patterns R and R
2 is formed to double surround the first gap G1,
A second gap G2 is formed between the inner conductor pattern R1 and the outer conductor pattern R2. In the illustrated example, the two inner and outer loop-shaped conductor pattern angles and R2
consists of one continuous conductor. Further, the inner deep part 3 of the inner gap G1 overlaps the top end of the pickaxe-like pattern P, which is the leading magnetic material pattern. In this configuration, when a pulse current of 1 g is passed in the direction of weakening the bias magnetic field HB so that a bubble b is created in the inner gap G, a bubble b is created in the gap G1 as in the case of FIG. Newly created. The timing for flowing 1 g of new create current is the first
As in the case shown in the figure, since the driving rotating magnetic field HR is directed in the direction of the hatched area 2, the generated bubble b is attracted and held at the top of the pickaxe-like pattern P. By the way, the outer loop-shaped conductor pattern R2 is continuous with the inner loop-shaped conductor pattern R1, so when a new creation current is passed through the inner loop-shaped conductor pattern R in the direction of arrow A, the outer loop-shaped conductor pattern R2 is continuous with the inner loop-shaped conductor pattern R1. A current flows in the opposite direction through the loop-shaped conductor pattern R2 as shown by an arrow A2. This current in the opposite direction acts in the direction of strengthening the bias magnetic field HB, contrary to the nucleation current, so the first gap G1, which is the nucleation region, has a strong magnetic field (bubble) in the same direction as the bias magnetic field H3. b will be surrounded by a repulsive magnetic field). Therefore,
The newly created bubble b cannot freely expand and increase in size as in the past, but is compressed from the outside. As a result, even after the nucleation current Ig is cut off, the bubble b is difficult to split and remains in a single, reduced state and is transferred to the next transfer patterns P2 and P3 as the bias magnetic field rotates. , malfunctions are effectively prevented. In the second embodiment, a T-shaped notch is formed to form the first gap G1, and the outside thereof is used as an inner conductor pattern, whereas in the second embodiment shown in FIG. A second cut is made to surround this L-shaped gap.
A gap G2 and an outer conductor groove R2 are formed.

The operation is the same as in Fig. 2, and the current flowing through the outer loop-shaped conductor pattern R2 generates a repulsive magnetic field surrounding bubble b, shrinking the newly created bubble and bringing it into a stable state. Become. In the third embodiment shown in FIG. 4, the magnetic material pattern P at the head of the transfer path has a shape obtained by deforming the half disk pattern into a substantially L-shape, and the edge of the top end 4 which becomes the attractive magnetic pole generation part along the first gap G
, is formed.

Note that the first and second gaps G, , G2 and the inner and outer conductor patterns R, , R2 have almost the same shape as in FIG. 3, but the first gap G, attracts the leading magnetic material pattern P1. As long as it is along the edge of the magnetic pole, the pattern shown in FIG. 2 or any other pattern shape may be used. In the case of FIG. 4, the energization timing of the nucleation current 1g is when the rotating magnetic field HR reaches a position orthogonal to the first gap G and the attractive magnetic pole 4, as shown by the hatched area 2'. According to this configuration, the strength of the magnetic field at the magnetized apex 4 is distributed in the direction of the rotating magnetic field, that is, in the direction of the hatched area, whereas the first gap that creates the nucleation magnetic field is perpendicular to it. Since the newly created bubbles b do not extend in a striped shape but are generated in a circular shape, the bubbles are more stable and excessive bubble generation can be reliably prevented. As described above, according to the present invention, the first gap forming the nucleation region is double surrounded by the two inner and outer loop-shaped conductor patterns Rl and R2, and when the nucleation current flows through the inner conductor pattern. In addition, since the outer conductor pattern is configured so that a current flows in the opposite direction, the repulsive magnetic field generated by the current flowing through the outer conductor pattern compresses the newly created bubble from the outside, causing it to become free. Extension becomes impossible. Therefore, malfunctions such as excessive bubble generation are reliably prevented, and the nucleation current margin and operating temperature range are widened, resulting in a magnetic bubble device that is extremely easy to use. In the case of the illustrated example, the inner conductor pattern R
, and the outer conductor pattern R2 are formed of one continuous pattern, but when a nucleation current flows through the inner conductor pattern, a current flows in the opposite direction to the outer conductor pattern. If so, there is no problem even if the inner and outer conductor patterns Rl and R2 are made independent.

[Brief explanation of drawings]

Figure 1 is a diagram showing the pattern of a conventional magnetic bubble generator;
2 to 4 are diagrams illustrating various patterns of the magnetic bubble generator according to the present invention.

Claims (1)

[Claims] 1. In a magnetic bubble generator that nucleates magnetic bubbles by generating a nucreation magnetic field in a magnetic bubble generation area inside a loop-shaped conductor pattern, the magnetic bubble generation area is double surrounded by a conductor pattern, and the inside A magnetic bubble generator characterized in that the outer conductor pattern is wired so that a nucleation current flows in the nucleation direction, and the outer conductor pattern is wired so that a current in the opposite direction to the nucleation current flows.