JPH0646496B2 - Magnetic bubble memory device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to magnetic bubble memory prevention, and in particular, magnetic bubble detection with reduced noise (hereinafter referred to as "Ankyncell noise") resulting from imbalance of magnetic ambient conditions. It relates to the structure of the container.

[Background of the Invention]

Generally, in a magnetic bubble memory device, a magnetic bubble detector is provided at the end of a read media line connected to a minor loop storing magnetic bubble information. Then, this magnetic bubble detector is a plurality of magnetic bubble expanders for expanding the magnetic bubbles transferred from the read media line into a string-like magnetic bubble having a length of about several hundred times.
It consists of a main bubble detector that detects the expanded magnetic bubble and a magnetic bubble detector that consists of a dummy detector.The presence or absence of magnetic bubbles can be detected by applying a constant current to these main detector and dummy detector. It has a function of converting into an electric signal by the magnetoresistive effect (Japanese Patent Laid-Open No. Sho 5)
5-1610).

However, in the magnetic bubble detector configured in this manner, the main detector and the dummy detector are affected by the in-plane rotating magnetic field that drives the magnetic bubble regardless of the presence or absence of the magnetic bubble. For this reason, the main detector and the dummy detector are formed in exactly the same pattern, and even though they are formed with an equivalent magnetoresistive effect, they cannot completely cancel the noise due to the influence of the rotating magnetic field. There is a difference in the magnitude of the magnetic resistance, and even when there is no magnetic bubble, the output of the operational amplifier does not always become zero, which causes un-cancelled noise.In extreme cases, the reference voltage value for comparison is exceeded, and the comparator This causes a malfunction of outputting the signal "1" where the signal "0" should be output. In particular, the occurrence of such un-cell noise is due to the magnetic bubble diameter of about 2.0μ.
It was remarkably shown in the magnetic bubble memory device of less than m. When the magnetic bubble detector constructed in this way is applied to a high density magnetic bubble memory device having a magnetic bubble diameter of less than 2.0 μm, the saturation magnetization is 4πM as shown in FIG.
There is a problem in that the level of the total noise N is further increased because the un- cancelled noise N ₂ is superimposed on the crosstalk noise N ₁ accompanying the increase of s.

[Object of the Invention]

It is an object of the present invention to provide a magnetic bubble memory device equipped with a magnetic bubble detector capable of reducing the occurrence of unscanned cell noise and obtaining a detection signal with a high S / N ratio.

Another object of the present invention is to provide a magnetic bubble memory device having magnetic bubble detection / erasing capable of obtaining a detection signal having a high S / N ratio by reducing the generation of the total noise level including crosstalk noise. Especially.

[Outline of Invention]

According to the present invention, the dummy expander 15 having the same transfer direction P and the same pattern as the main expander 11 has three or more stages, and the dummy detection environment is brought closer to the main detection environment. According to the present invention, the following magnetic bubble memory device is provided, in which the value of the noise N is greatly reduced as shown in FIG.

The magnetic bubble expander and the detector are provided with a plurality of magnetic bubble expanders in which (a) a plurality of V-shaped patterns are arranged in the transfer direction (P) order in the direction perpendicular to the transfer direction. Magnetic bubble main expander, (b) Main detector line (12) for detecting the presence or absence of magnetic bubbles, (c) Magnetic bubble eraser (13), (d) Preventing intrusion of unnecessary magnetic bubbles A guardrail (16), (e) a magnetic bubble dummy expander (15) having three or more expanders configured in the same pattern with the same transfer method as the main expander, and (f) the main detector line And a dummy detector line (14) configured in the same pattern as the above.

Example of Invention

 Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan configuration diagram for explaining one embodiment of a magnetic bubble memory device according to the present invention. In the figure, 1
Is a minor loop for storing information, 2 is a read media line for transferring read information, 3 is a write media line for transferring write information, 4 is a separate type bit read magnetic bubble detector for converting magnetic bubbles into electric signals,
5 is a magnetic bubble generator for writing information on the write media line 3, 6 is a replicate gate for copying the information on the minor loop 1 to the read media line 2, and 7 is information on the write media line 3 and the minor loop 1. Swap gates for exchanging information inside, 8 are guard rails for preventing invasion of unnecessary magnetic bubbles from the outer periphery, and 9 is a bonding pad for connecting these transfer circuits to an external circuit.

Further, the replicate gate 6, the swap gate 7 and the magnetic bubble generator 5 are controlled depending on whether or not a current in a fixed direction is passed through a conductor in another layer arranged in a special relationship with the permalloy transfer pattern, and the conductors in the figure are controlled. The portion is shown by a thick solid line, and the remaining thin solid line shows a permalloy transfer pattern.

FIG. 2 is an enlarged plan view of an essential part showing the magnetic bubble detector 4 of FIG. In the figure, the magnetic bubble detector 4 is composed of a main detector 4A and a dummy detector 4B. Reference numeral 11 is a plurality of magnetic bubbles transferred from the read media line 2 and gradually extended to a string-like magnetic bubble. , A thick film type main detector line 12 for detecting the presence or absence of magnetic bubbles by transferring the magnetic bubbles stretched in a string shape in the direction of arrow P.
Reference numeral 13 is a magnetic bubble eraser, 14 is a thick film type dummy detector line, and 15 is a dummy expander.
5 is the first expander line 15a and the second expander line 15b
And a third expander line 15c, which is a three-stage expander line. In addition, 16 is a line of the guardrail 8 shown in FIG.

In the separate type bit read magnetic bubble detector 4 configured as described above, the number of stages of the dummy expander 15 on the side opposite to the magnetic bubble transfer direction P of the dummy detector line 14 is set to three, so that the dummy detector Since the magnetic ambient conditions of line 14 approach the magnetic ambient conditions of main detector line 12, anxencell noise can be reduced.

FIG. 3 shows a signal voltage when the above-mentioned magnetic bubble detector 4 is applied to a magnetic bubble memory device having a magnetic bubble diameter of 1.85 μm in comparison with a conventional one. In FIG. 3, S is a signal output. , N represents the total noise including the Ancyan cell noise and the crosstalk noise. As is clear from the figure, the magnetic bubble detector 4 according to the present invention was able to reduce the level of the total noise N to about 2/3 as compared with the conventional one.

FIG. 4 is a diagram for explaining another embodiment of the present invention. In the figure, the dummy expander 15 shown in FIG.
4 shows how the level of the total noise N is reduced when the number of stages is increased from 3 to 4, 5, 6, and 12. As is clear from the figure, the dummy expander 1
By increasing the number of stages of 5, the magnetic ambient condition of the dummy detector line 14 was brought closer to the main detector line 12, so that the noise level could be reduced asymptotically.

FIG. 5 is an enlarged plan view of an essential part showing another embodiment in which the present invention is applied to a thin film magnetic bubble detector, and the same parts as those in the above-mentioned drawings are designated by the same reference numerals. In the figure, the main detector line 12 'and the dummy detector line 14' are formed in a thin film type permalloy pattern, and the thin film type dummy detector line 14 'has three stages on the side opposite to the magnetic bubble transfer direction P. The dummy expander 15 including the dummy expander lines 15a, 15b, and 15c is provided.

Even with such a configuration, the same operational effects as those of the thick film type magnetic bubble detector described above can be obtained. Even if the number of stages of the dummy expander 15 is three or more, the magnetic ambient condition of the dummy detector line 14 'approximates to that of the main detector line 12'. Is obtained.

〔The invention's effect〕

As described above, according to the present invention, it is possible to obtain a detection signal having a high S / N ratio by reducing the generation of the total noise including the Ankyan cell noise and the crosstalk noise. An extremely excellent effect that a memory device can be realized is obtained.

[Brief description of drawings]

FIG. 1 is a plan configuration diagram showing an embodiment of a magnetic bubble memory device according to the present invention, FIG. 2 is an enlarged plan view of an essential portion showing a first magnetic bubble detector, and FIG. FIG. 4 is a diagram showing an output signal of a bubble detector, FIG. 4 is a diagram showing a noise reduction state with an increase in the number of stages of a dummy expander, and FIG. 5 is a main part of a magnetic bubble detector showing another embodiment of the present invention. FIG. 6 is an enlarged plan view showing the dependence of the detection signal voltage on the magnetic bubble diameter. 2 ... Read media line, 4 ... Magnetic bubble detector,
4A ... main detector, 4B ... dummy detector, 11 ...
… Expander, 12 …… Thick film type main detector line, 12 ′
...... Thin film type main detector line, 13 ...... Magnetic bubble eraser, 14 ...... Thick film type dummy detector line, 14 '......
Thin-film dummy detector line, 15 ... Dummy expander, 15
a, 15b, 15c …… Expander line, 16 …… Guardrail line.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Yanai 3300 Hayano, Mobara-shi, Chiba Hitachi Mobara factory (72) Inventor Hironori Kondo 3300 Hayano, Mobara-shi, Chiba Hitachi Ltd. Mobara factory (72) Inventor Nakadai Dai Hiro 1479, Kamimizuhonmachi, Kodaira-shi, Tokyo In-house Hitachi Micro Computer Computer Co., Ltd. (56) Reference US Patent 4300209 (US, A)

Claims (1)

[Claims] 1. A magnetic bubble memory device comprising a magnetic bubble magnifier and a detector, wherein the magnetic bubble transfer direction (P) in the magnifier and the detector is in the order of: A magnetic bubble main expander provided with a plurality of magnetic bubble expanders in which a plurality of circular patterns are arranged in a direction perpendicular to the transfer direction; (b) a main detector line (12) for detecting the presence or absence of magnetic bubbles; c) a magnetic bubble erasing device (13), (d) a guardrail (16) for preventing invasion of unnecessary magnetic bubbles, and (e) an expander configured with the same transfer direction and the same pattern as the main expander described above. A magnetic bubble dummy expander provided in three or more stages (15); and (f) a dummy detector line (14) configured in the same pattern as the main detector line. Magnetic bubble memory device.