JPS59178678A - Magnetic bubble device - Google Patents

Abstract

PURPOSE:To simplify the assembly, reduce the power consumption, and improve the capacity of disturbance-resisting magnetic field with one magnetizing coil by selecting magnetization direction of two kinds of semihard magnetic film to transfer bubbles. CONSTITUTION:A bubble magnetic film 22 is formed on a substrate 21, and rectangular magnetized films 23a and 23b consisting of semihard magnetic materials different in reluctance are formed on the magnetic film 22 so that one sides of them are matched to each other. Magnetization of films 23a and 23b is inverted selectively in accordance with the intensity and the direction of magnetization of a coil 2 whose magnetization direction is set to the arrangement direction of films 23a and 23b, thus transferring bubbles.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a magnetic bubble device that is easy to assemble, consumes little power, and can stably hold and hold magnetic bubbles stationary.

(Background Art) Conventionally, the magnetic bubble transfer method of this type of device is a field access type, that is, magnetizes the L & vermaloids and turns formed on the bubble magnetic film with rotating magnetic fields from X and Y coils, and the magnetic bubble is transferred by the gradient of the leakage magnetic field. What is transferred is well known.

However, in this method, it is naturally impossible to cut off the x, y coil currents that generate the magnetic field gradient while the magnetic bubble is being moved. In addition, in order to move the magnetic bubble smoothly, the current flowing through the two coils is preferably a current that is close to a sine wave and has an electrical phase difference of π/2.
For this reason, the semiconductor elements of the driver and the like are used in an analog manner, which consumes a large amount of power.

Furthermore, the magnetic field barrier that keeps the magnetic bubble stationary is...
Due to the slight decrease in the bias magnetic field due to the presence of the Malloy film, this magnetic field barrier can be only a small barrier compared to the magnetic field when transferring the magnetic bubble, and the magnetic field gradient due to the non-uniformity of the bias magnetic field. , can easily move due to magnetic field gradients caused by external disturbance magnetic fields.

Therefore, the current situation is that the uniformity of the bias magnetic field is strictly required and the magnitude of the disturbance magnetic field is strictly limited.

(Problems to be solved by the invention) In order to eliminate these drawbacks, the present invention forms two types of rectangular semi-hard magnetic films, each having a different coercive force, on a bubble magnetic film, and then connects them with a certain degree of contact. The 6D magnetized coils arranged in a row provide a unique magnetic bubble device and will be described in detail below.

(Structure and operation of the invention) FIG. 1I is a perspective view of essential parts showing an embodiment of the present invention, in which 1 is a magnetic bubble chip and 2 is a magnetizing coil.

Figure 2 (a) is a partial plan view of the magnetic bubble chip, (b)
1 is a partial view, in which a bubble magnetic film 22 is formed on a substrate 21, and rectangular magnetized films 23g and 23b made of a semi-hard magnetic material are formed on top of the bubble magnetic film 22 so that one side abuts against the other. These rectangular magnetized films 23a and 23b have magnetization characteristics as shown by the B-H characteristic curve in FIG. 3. For example, curve 31 in FIG. Characteristic. Reference numeral 32 indicates a straight line of motion of the magnetized film in the arrangement shown in FIG. 1III line 3
The coercive force Hca of curve 32 is approximately half of the coercive force H8 of curve 32, and in the range where the magnetization strength is greater than H and smaller than Hcb, only the magnetization of curve 31 is reversed, and the magnetization strength is When it is larger than Hcb, the structure is such that the magnetization of curves 31 and 32 is reversed.

FIG. 4 is a diagram explaining the operation of this embodiment. As shown in FIG. 4(a), when the magnetizing force generated by the magnetizing coil 2 of FIG. 1 is greater than Hcb of FIG. 3, the magnetization direction is as shown in FIG. If it is like the arrow 41 in (a), the magnetized films 23a, 23b
are magnetized in the directions of arrows 42a and 42b in the figure. Note that 43 is the direction of the bias magnetic field. Therefore, the bubble magnetic film 22 is magnetized in the same direction as the bias magnetic field 43, but only the magnetic bubble 44 is naturally magnetized in the opposite direction to the bias magnetic field 43. Now, 42a in Figure 4(a)
, 42b, the magnetic bubble 44 is attracted to one end of the magnetized film 23a. In other words, the leakage magnetic field in the bubble magnetic film 22 due to the magnetizations 42 a and 4.2 b has an energy impact on the magnetic bubble 44 because the position of the magnetic bubble 44 shown in the figure is the position where the bias magnetic field is most reduced. It is the smallest position.

Next, as shown in FIG. 4(b), the magnetizing force 41 is changed to Hca in FIG.
and Hcb, and when the direction is opposite to that shown in FIG.
b is its "!l: unity. Therefore, the leakage magnetic field in the direction of reducing the bias magnetic field 43 is the magnetization M 23 a in the same figure (b)
The position of the magnetic bubble 44, which is the abutting portion between and 23b, is the closest position. This causes the magnetic bubble 44
will move from the position shown in (a) of the same figure to the position shown in (b) of the same figure.

Similarly, in FIG. 4(c), when the magnetizing force 41 has the same magnitude as that in FIG. 4(a) but the direction is opposite, the magnetization of the magnetized film 23b causes magnetization reversal, and the magnetization direction of the magnetized film 23a, that is, the magnetizing force 41. They will be in the same direction. As a result, the magnetic bubble 44 becomes the magnetized film 23b.
It is stabilized by being drawn to the edge of the

(5) Next, as shown in Figure 4(d), if a magnetizing force 41 is applied in the opposite direction to that in Figure 4(C), the magnetization direction in this case is as shown in Figure 4(a).
Although it is exactly the same as in the case of , the magnetic bubble 44 is stabilized at the end of the magnetized film 23a at a position one pitch ahead.

In this way, Figure 4 (a) → (b) → (C) → (,)
→ When magnetization 41 is applied as in..., magnetic bubble 44
will be transferred from the paper piece to the right.

FIG. 5 is a model diagram of the current flowing through the magnetizing coil 2 of FIG. 1, and the horizontal axis is time. Current 51. ．． The size and direction of 52°53 are shown in (a), (b), and (c) in Figure 4.
correspond to the magnetization 41 of .

(Effects of the Invention) As explained above, the transfer of magnetic bubbles is achieved by selectively changing the magnetization direction of two types of semi-hard magnetic films with different coercive forces formed on the magnetic film. Therefore, the number of magnetizing coils is one (31), and the current flowing through the magnetizing coil is only the time required to reverse the magnetization of the hard magnetic film.

Generally, the time required to reverse the magnetization of semi-hard magnetic materials (6) can be considerably reduced by increasing the current rise speed.

In addition, the field barrier that keeps the magnetic bubble stationary is
Since the magnitude is the same as the magnetic field that transfers the magnetic bubbles, the magnetic bubbles will not move in arbitrary directions due to non-uniformity of the bias magnetic field or disturbance magnetic fields.

Therefore, it is possible to obtain a magnetic bubble device that is easy to assemble, consumes little power, and has excellent resistance to disturbance magnetic fields.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the main parts showing one embodiment of the present invention, and FIG. 2 (
a) and (b) are a partial plan view and a sectional view of the magnetic bubble chip, FIG. 3 is an explanatory diagram of the operation in the embodiment, and FIG.
) to (d) are B-H characteristic curves of the magnetized film, and FIG. 5 is a model diagram of the current flowing through the magnetized coil. 1... Magnetic bubble chip, 2... Magnetizing coil, 21
... Substrate, 22 ... Bubble magnetic film, 23a, 23b
. . . Rectangular magnetized film, 41 to 44 . . . Arrows indicating magnetization directions. (7)

Claims (1)

[Claims] A magnetic bubble chip in which two types of rectangular semi-hard magnetic films, each having a different coercive force, are formed on a bubble magnetic film with one end abutting each other, and these are arranged in a line with a constant pitch;
By having a magnetization coil whose magnetization direction is aligned with the arrangement direction of the semi-hard magnetic films, and selectively reversing the magnetization of the two types of semi-hard magnetic films depending on the magnitude and direction of magnetization of the magnetization coil. A magnetic bubble device characterized by transferring magnetic bubbles.