JPH0944104A - Magnetic reversal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic reversal display device capable of imparting a sufficient reverse driving force for reversibly driving a big display plate without depending on the characteristics of a semi-hard magnetic material such as the remanent magnetic flux density, coercive force, magnetic permeability or the like. SOLUTION: In a magnetic reverse display device provided with a display plate 1 having different colors in front and back surfaces supported so as to be reversed, permanent magnets 2 and 3 respectively provided in both ends of the display plate 1, yokes 8 provided in positions respective facing both permanent magnets 2 and 3 and an electromagnetic device 7 for exciting these yokes 8 to be applied to both permanent magnets 2 and 3 and reversibly driving the display plate 1, each of the yokes 8 is composed of a combination between a main yoke 8a made of a semi-hard magnetic material and an auxiliary yoke 8b made of a soft magnetic material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reversal display device capable of reversing a display plate by an electromagnet device to display a desired image.

[0002]

2. Description of the Related Art As shown in FIG. 1, a conventional magnetic reversal display device has a display plate 1 having permanent magnets 2 and 3 at both ends thereof.
Is supported by the support case 6 in a reversible manner, and on the support case 6 side, a pair of yokes 8 and 8 are arranged so that the upper ends thereof face the permanent magnets 2 and 3 at both ends of the display plate 1 with a predetermined gap. Is upright. The lower ends of the yokes 8 and 8 are press-fitted and fixed to a coil iron core 9 made of a soft magnetic material provided in the support case 6, and the coil bobbin 10 is attached to the coil iron core 9.
The coil 11 is wound around the coil 11 and constitutes an electromagnet device as a whole. This electromagnet device excites the yokes 8 and 8 to apply a magnetic attraction force or repulsive force to the permanent magnets 2 and 3 at both ends of the display plate 1 by the residual magnetic flux generated at the tips of the yokes 8 and 8. The display plate 1 is driven to be reversed (for example, Japanese Patent Laid-Open No. 56-6228).
No. 7, Japanese Patent Publication No. 63-35987, Japanese Patent Publication No. 3-3931
No. 6). A plurality of magnetic reversal display devices (1 unit) can be arranged in parallel to display characters and symbols. In such a conventional magnetic reversal display device,
The pair of yokes provided to face the permanent magnets 2 and 3 at both ends of the display plate 1 are made of, for example, a semi-hard magnetic material containing iron, cobalt, and vanadium as main components. Its magnetic permeability (permeability) and coercive force are smaller than those of hard magnetic materials, specifically about 30 Oe
(2400A / m) to 180 Oe (14400A / m)
The material is up to about m), and has a characteristic that magnetic poles (N pole, S pole) that have been once magnetized can be easily reversed by a magnetizing force from the outside.

[0003]

The surface magnetic flux of the permanent magnets at both ends of the display plate which is generally used is around 600 gauss, and in order to give a starting torque and a rotational force to this permanent magnet, there is a certain constant value. It is necessary to generate a magnetic force equal to or more than the above value at the tip of the yoke. However, for example, when the number of turns of the coil is 500 and a current of 1 amp is applied for 1 millisecond, a magnetic force of about 1200 gauss is generated at both ends of the coil iron core, but a length of about 100 millimeters (Fig. When a yoke made of a semi-hard magnetic material having the symbol a) in 1 is used, the magnetic force at the tip (the portion facing the permanent magnet) is 300 because the magnetic permeability (magnetic permeability) and the coercive force are small. It becomes as low as Gauss, which is not enough to give a starting torque and a rotational force to the permanent magnet. As described above, in the conventional device, the residual magnetic flux generated at the tips of the pair of yokes made of semi-hard magnetic material provides a static stabilizing force (locking force) with the permanent magnets at both ends of the display plate. Since the magnetic field generated at the tip of the yoke when the coil is energized also provides the starting torque and the rotational force to the permanent magnets at both ends of the display plate, the residual magnetic flux density of the semi-hard magnetic material,
The performances of the static stabilizing force (locking force) and the rotating force described above depend on the characteristics such as coercive force and magnetic permeability, and the length of the yoke (symbol a in FIG. 1) cannot be made longer than necessary. Therefore, there is a problem that a sufficient reversal driving force cannot be applied when reversing driving a large display plate. It is an object of the present invention to provide a magnetic reversal drive force sufficient to reversely drive a large display plate without depending on the characteristics of the semi-hard magnetic material such as the residual magnetic flux density, coercive force, and magnetic permeability. An object is to provide a reverse display device.

[0004]

In order to solve the above-mentioned problems, the present invention provides a display plate which is supported in a reversible manner and whose front surface and back surface have different colors, and which is provided at each end of the display plate. A permanent magnet, a yoke provided at a position facing each of the permanent magnets, and an electromagnet device for exciting the yoke to magnetically act on the permanent magnets to reversely drive the display plate. In the magnetic reversal display device described above, the yoke is a combination of a main yoke made of a semi-hard magnetic material and an auxiliary yoke made of a soft magnetic material. One of the main yoke and the auxiliary yoke may have a hollow cylindrical shape, and the other may fit inside the hollow cylindrical shape to form a yoke. The main yoke and the auxiliary yoke may be overlapped with each other along the extending direction to form a yoke.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numerals in the figure are the same as those shown in FIG. 1 for explanation. As shown in FIG. 2, the thin display panel 1 having a substantially octagonal planar shape is made of a non-magnetic material such as aluminum or plastic, the front surface of which is a bright color such as fluorescent color and the back surface of which is light. Each is colored in a dark color that does not reflect. A pair of circular permanent magnets 2 and 3 that rotate together with the display plate 1, and a pair of circular permanent magnets that rotate together with the display plate 1 and support the display plate 1 in a reversible manner with respect to a support case described later. A pair of rotation support shafts 4 and 5 for engaging with each other are engaged with each other. Circular permanent magnets 2, 3
Is a plastic magnet that is formed by mixing plastic and magnet powder particles, has a substantially cylindrical shape, and its outer peripheral surface is magnetized into two poles, an N pole and an S pole. The ones around Gauss are used.

The support case 6 consisting of the upper case 61 and the lower case 62 is provided with a predetermined space between them.
a and 6b are erected, and circular support holes 6c and 6d are formed in each of the support arms 6a and 6b. By inserting the shaft portions 4a, 5a of the rotation support shafts 4, 5 into the support holes 6c, 6d, one unit of the magnetic reversal display device is completed.

An electromagnet device 7 is built in the support case 6, and its configuration will be described. A pair of yokes 8 and 8 whose upper ends face the outer peripheral surfaces of the circular permanent magnets 2 and 3 with a predetermined space therebetween are erected. The lower ends of the yokes 8 and 8 are press-fitted and fixed to a coil core 9 in the support case 6, and a coil 11 is wound around the coil core 9 via a coil bobbin 10, and the electromagnet device 7 as a whole. Are configured. Here, the yokes 8 and 8 have the same structure on the left and right sides, and are a combination of a main yoke 8a and an auxiliary yoke 8b as shown in FIGS. As shown in FIG. 2, the auxiliary yoke 8b has a hollow cylindrical shape, and the main yoke 8a is fitted inside the hollow cylindrical shape of the auxiliary yoke 8b to form the yoke 8. In this embodiment, the upper end of the main yoke 8a slightly protrudes from the upper end of the auxiliary yoke 8b.

The main yoke 8a is made of, for example, a semi-hard magnetic material containing iron, copper, molybdenum or iron, cobalt, vanadium as a main component, and the semi-hard magnetic material has a magnetic permeability (permeability) and a magnetic permeability. The magnetic force is smaller than that of a hard magnetic material, specifically about 30 Oe (240
It is a material of about 0 A / m) to about 180 Oe (14400 A / m) and has a characteristic that magnetic poles (N pole, S pole) once magnetized by an external magnetizing force can be easily reversed. When a semi-hard magnetic material containing iron, cobalt, and vanadium as the main components is used, its coercive force can be changed from 30 Oe to 1 by changing the vanadium composition in the components.
It is possible to manufacture materials up to 80 Oe. The auxiliary yoke 8b is made of a soft magnetic material such as iron, nickel alloy or pure iron, and this soft magnetic material has its magnetic permeability (permeability).
Is high and the coercive force is small. In this way, the circular permanent magnets 2,
3 is formed by combining the main yoke 8a made of a semi-hard magnetic material and the auxiliary yoke 8b made of a soft magnetic material in the yoke 8 facing the magnetic flux No. 3, so that the residual magnetic flux generated at the tip of the yoke 8 is generated. Does not depend only on the magnetic permeability (magnetic permeability) of the semi-hard magnetic material, it is possible to generate a magnetic force at the tip of the yoke sufficient to give the starting torque and the rotational force to the circular permanent magnets 2, 3. .

When the number of turns of the coil 11 is 500 and a current of 1 amp is applied for 1 millisecond, a magnetic force of about 1200 gauss is generated at both ends of the coil iron core, but a length of about 100 millimeters. When a yoke 8 having a diameter (symbol a in FIG. 1) is used, the magnetic force at its tip (the portion facing the permanent magnet) is experimentally about 1150 gauss, which is sufficient for circular permanent magnets 2 and 3. Starting torque and rotational force can be applied, and the display plate 1 can be reliably driven in reverse. Therefore, the length of the yoke (reference numeral b in FIG. 2) can be increased,
The large display panel 1 can be driven in reverse.

In the first embodiment described above, the auxiliary yoke 8b has a hollow cylindrical shape, and the main yoke 8a is fitted inside the hollow cylindrical shape of the auxiliary yoke 8b to form the yoke 8. Conversely, the main yoke 8a may have a hollow cylindrical shape, and the auxiliary yoke 8b may be fitted inside the hollow cylindrical shape of the main yoke 8a to form the yoke 8. 4 and 5 show a second embodiment of the yoke, which is a main yoke 80a made of a semi-hard magnetic material and an auxiliary yoke 80 made of a soft magnetic material.
Both b are plate-shaped and overlap each other in the extending direction to form a yoke 80. Other configurations are substantially the same as those of the first embodiment described above.

[0011]

As described above, according to the present invention,
Since the main yoke made of semi-hard magnetic material and the auxiliary yoke made of soft magnetic material are combined in the yoke facing the permanent magnet, the residual magnetic flux generated at the tip of the yoke is semi-hard. Magnetic permeability (permeability) of magnetic materials
Since it does not depend on only the magnetic field, it is possible to generate enough magnetic force at the tip of the yoke to give a starting torque and a rotational force to the permanent magnet, and it is possible to reliably drive the display plate in reverse. Therefore, the length of the yoke can be increased, and a large display plate can be driven in reverse.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conventional magnetic reversal display device.

FIG. 2 is a cross-sectional view of a magnetic reversal display device according to the present invention.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 2;

FIG. 4 is a cross-sectional view of main parts showing another embodiment of the yoke.

FIG. 5 is an enlarged sectional view taken along line BB of FIG. 4;

[Explanation of symbols]

 1 display board 2,3 permanent magnet 7 electromagnet device 8,80 yoke 8a, 80a main yoke 8b, 80b auxiliary yoke

Claims (3)

[Claims] 1. A display plate which is supported in a reversible manner and whose front and back surfaces are different in color, permanent magnets provided at both ends of the display plate, and positions facing the permanent magnets. In a magnetic reversal display device including a provided yoke and an electromagnet device for exciting the yoke and magnetically acting on the permanent magnets to reversely drive the display plate, the yoke is semi-hard. A magnetic reversal display device comprising a main yoke made of a magnetic material and an auxiliary yoke made of a soft magnetic material in combination. 2. Of the main yoke and the auxiliary yoke,
2. The magnetic reversal display device according to claim 1, wherein one is a hollow cylinder and the other is fitted inside the hollow cylinder to form the yoke. 3. The magnetic reversal display device according to claim 1, wherein the main yoke and the auxiliary yoke overlap with each other along the extending direction to form the yoke.