JPH10125532A - Demagnetizer for electric equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive demagnetizer which can be applied to any kind of electric equipment and can prevent the leaking out of a magnetic field generated from the electric equipment. SOLUTION: Closed-loop coils 1 made of conductors are respectively provided in the enclosure 2 and doors 3 of a refrigerator R1 and, when a magnetic flux generated from electric parts housed in the refrigerator R1 passes through one of the coil 1, an induced electromotive force is generated in the coil 1 by the law of electromagnetic induction and the force generates a magnetic field. The generated magnetic field prevents the leaking out of the magnetic flux generated from the electric parts by compensating the magnetic flux.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be applied to all electric appliances such as refrigerators, air conditioners, televisions, etc., cancels out the magnetic field generated and leaked from the electric appliances, and removes the influence of the leaked magnetic field on the human body. The present invention relates to a degaussing device for electrical equipment for performing

[0002]

2. Description of the Related Art Generally, an electric device always generates a magnetic field due to the action of a current flowing in the device.
This magnetic field is generated in the direction of the right-hand screw with respect to the direction in which the current flows.

When an alternating current flows as in a commercial power supply, the direction of a magnetic field generated by the alternating frequency changes.
A so-called alternating magnetic field is generated.

[0004] For example, in the case of a refrigerator, a compressor for compressing a built-in refrigerant to cool the inside of the refrigerator, a fan motor in the refrigerator for circulating cool air in the refrigerator, a surface heater for preventing dew condensation in the freezer, and various function controls are provided. Although various electric components such as control circuit components are stored therein, magnetic fields are generated from the respective electric components, so that a magnetic field having a magnitude that cannot be ignored in the refrigerator as a whole is generated. In particular, an alternating magnetic field is generated from a compressor driven by an alternating current, a fan motor in a refrigerator, a surface heater for preventing dew condensation, and the like.

[0005] The influence of the magnetic field generated from the electric equipment on general electric equipment can be said to be small to a certain extent. However, for example, when the video / audio equipment is installed at a short distance from the refrigerator, the effect is relatively small. When an audio-visual (AV) product that is sensitive to a magnetic field is used near an electric device that generates a strong magnetic field,
There is a high risk of giving noise to the product. Also recently,
It has been reported that the magnetic field generated as described above, particularly an alternating magnetic field, has an undesired effect on the human body, and social interest is increasing.

As a prior art for suppressing the magnetic field and the electric field generated together with the magnetic field, for example, Japanese Patent Laid-Open No.
Japanese Patent No. 5335 discloses a device that suppresses a magnetic field generated from a deflection yoke used in a cathode ray tube such as a display device. In this prior art example, a cancel coil driven by a current synchronized with a vertical deflection current is provided outside the deflection yoke, and a magnetic field in a direction opposite to a leakage magnetic field from the deflection yoke is generated by the cancel coil. It is configured to cancel and reduce the magnetic field leaking from the deflection coil.

[0007]

However, as in the above-mentioned prior art example, in the leakage magnetic field reduction measure by flowing a current synchronized with the driving current of the deflection yoke to the cancel coil, the individual flow of electricity inside the electric equipment is not considered. For all of the components, a cancel coil must be provided, and a current synchronized with a current for driving the component must be supplied to the cancel coil. For example, in the case of the above-mentioned refrigerator, a compressor, a fan motor in a refrigerator, a control circuit,
A cancel coil must be provided for all components that generate a magnetic field, such as a dew condensation prevention surface heater, and a current synchronized with a current for driving this component must be supplied to the cancel coil.

[0008] Therefore, according to the above prior art example, the manufacturing cost is very high. Therefore, in practice, only a part of the components is used, such as a cathode ray tube of a display device shown in the prior art example. Therefore, it is difficult to use it for ordinary electric equipment, and there is a problem that it is practically impossible to take measures against demagnetization corresponding to a magnetic field generated from electric equipment in general.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is inexpensive and can be used for all kinds of electric devices, and can effectively reduce the magnetic field generated from those electric devices. It is intended to provide a device.

[0010]

First, prior to describing specific technical means of the present invention, its basic principle will be described. As mentioned above, the magnetic field generated by electrical equipment is
When current flows through various electrical components inside the device,
It occurs in the right-handed screw direction of the current.

FIG. 1 is for explaining the basic principle of the first configuration of the present invention. As shown in FIG. 1A, a closed loop coil L made of a conductor is connected to an electric device H shown by a dotted line. If it is disposed outside, the magnetic flux passing through the closed-loop coil L changes due to electromagnetic induction according to Lenz's law, and an electromotive force is generated in a direction that hinders the change in magnetic flux, and the current e ₀ flows. The direction of the current e ₀ generated in the closed loop coil L is opposite to the direction of the current e ₁ flowing through the internal component P of the electric device H.

Therefore, the magnetic field generated by this is also in the opposite direction, and the magnetic field generated from the closed loop coil L is:
The magnetic field generated from the electric device 1 cancels each other.
That is, when the magnetic field generated from the electric device H is the upward magnetic flux m ₁ as shown by the broken arrow, the closed loop coil L generates the downward magnetic flux m _{0 as} shown by the solid arrow.
As a result, the magnetic field generated from the electric device H is reduced.

Further, as shown in FIG.
When a current e ₁ ′ in the opposite direction flows through the internal component P, a magnetic flux m ₁ ′ in the opposite direction is generated as shown by the downward dashed arrow. In this case, an electromotive force is generated in the closed loop coil L by the linkage magnetic flux due to the downward magnetic flux m ₁ ′, and a current e ₀ ′ flows in a direction that hinders a change in the magnetic flux. ₀ ′ is generated, the magnetic flux m ₁ ′ of the electric device H is canceled, and the magnetic field is reduced.

Further, even in the case of an alternating magnetic field in which the direction of a magnetic field generated by the flow of an alternating current through an electric device changes, the process shown in FIGS. 1A and 1B is repeated, and the closed loop coil L The magnetic flux of the electric device H is canceled, and the magnetic field is reduced.

A first technical means of the present invention for achieving the above object is to utilize the above-mentioned basic principle, and to provide a housing of an electric device or a magnetic field generating source attached to the electric device. A demagnetizing device for electric equipment is constituted by a closed loop coil made of a conductor surrounding the magnetic field, thereby minimizing the leakage of the magnetic field generated from the electric equipment to the outside.

FIG. 2 is for explaining the basic principle of the second configuration of the present invention. As shown in FIG. 2A, a closed loop coil L is arranged outside an electric device H for generating a magnetic field. Then, the current e ₂ flows through the closed loop coil L by the current generating circuit C so that a magnetic field equivalent to the magnetic field generated by the internal component P of the electric device H is generated in the opposite direction.
If the magnetic field generated is an upward magnetic field m ₃ indicated by the dashed arrows from the flow a current e ₂ in the direction of downward magnetic field m ₂ indicated by the solid line arrows is generated from the closed loop coil L. e ₃ is a current flowing through the internal component P of the electric device H. Thus, the magnetic field generated from the closed loop coil L and the magnetic field generated from the electric device 1 cancel each other, and the magnetic field leaking to the outside is reduced.

Further, as shown in FIG.
When a reverse current flows through the internal component P to generate a reverse magnetic field indicated by a downward dashed arrow, the current generating circuit C
As a result, a current e ₂ ′ flows in the closed loop coil L in the opposite direction to generate a magnetic field m ₂ ′ equivalent to the generated magnetic field m ₃ ′ in the opposite direction, as shown by the upward solid line arrow, thereby making the electrical equipment H Is canceled out, and the leakage magnetic field is reduced.

Further, even in the case of an alternating magnetic field in which the direction of a magnetic field generated by the flow of an alternating current through the electric device H changes, the process shown in FIGS. 2A and 2B is repeated.
When an alternating current is caused to flow in the closed loop coil L by the current generating circuit C so as to generate a magnetic field equivalent to cancel the magnetic field generated from the electric device H, the leakage magnetic field is reduced.

A second technical means of the present invention for achieving the above-mentioned object utilizes the above-mentioned basic principle, and comprises a housing of an electric device or a magnetic field generating source attached to the electric device. A closed-loop coil made of a conductor covering the closed-loop coil, a current generating circuit for supplying a current to the closed-loop coil, a generated magnetic field detection unit for detecting the strength and direction of a magnetic field generated inside the electric device, and a generated magnetic field detection A current control unit for controlling the magnitude and direction of the current flowing through the closed loop coil in response to the magnetic field detection signal from the unit, thereby minimizing the leakage of the magnetic field generated from the electric device to the outside as much as possible. I am trying to do it.

In the first and second technical means of the present invention, the closed-loop coil may be formed in a multi-turn loop structure so as to reduce the leakage magnetic field more efficiently. Further, since the closed-loop coil is formed by fixing a conductive material to a housing of an electric device in a layered manner, the configuration can be made inexpensive and can be installed in a place having a complicated shape. Further, by providing the closed loop coil so as to surround the housing of the electric device or the front and rear, left and right, and up and down of the magnetic field generation source attached to the electric device, it is possible to further reduce the leakage of the magnetic field to the outside. .

Further, in the second technical means of the present invention, by providing the generated magnetic field detecting section on the operation surface side of the electric equipment, the magnetic field in a place closer to the human body can be measured, and the magnetic field can be reliably measured. The leakage magnetic field to the human body side can be reduced.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a degaussing apparatus for electric equipment according to the present invention will be described below in detail with reference to the drawings. FIG. 3 shows a refrigerator provided with the degaussing device for electric equipment according to the first embodiment of the present invention. A refrigerator R1 as an electric device shown in FIG. 1 is provided with doors 3 on the front surfaces of a refrigerator room, a freezer room, a vegetable room (none of which is shown) provided in a housing 2, and the like. Inside the refrigerator R1 having an outer shell constituted by the housing 2 and the plurality of doors 3, a compressor for compressing a built-in refrigerant for cooling the inside of the refrigerator, a fan motor for circulating cool air in the refrigerator, Various electric components (not shown) such as a control circuit component for controlling various functions and a surface heater for preventing dew condensation in a freezer.
Is stored.

Each of the above-mentioned electric components housed in the refrigerator R1 is a magnetic field generating source that generates a magnetic flux when driven. In the present embodiment, the electric conduction is provided to the housing 2 and the doors 3 respectively. A closed loop coil 1 made of a body is provided, and the closed loop coil 1 surrounds the component serving as the magnetic field generation source. As the conductor constituting the closed loop coil 1, any material can be used as long as it is a wire having a small electric resistance. Here, the most general copper wire is used. In the present embodiment, the closed loop coil 1 is made of a copper wire.
When the housing 2 is a conductor, for example, an iron plate, the housing itself may be configured to be the closed loop coil 1.

Thus, the housing 2 and the door 3 of the refrigerator R1
When the conductor closed loop coil 1 is arranged so as to surround an internal component or the like that generates a magnetic field, the magnetic flux Φ generated from inside the refrigerator R1 passes through the closed loop coil 1.
At this time, according to the law of electromagnetic induction, an electromotive force e is generated in the closed loop coil 1 in a direction that hinders a change in magnetic flux, as shown in Expression (1).

E = −ΔΦ / Δt [V] (1) Due to the induced electromotive force e, a current flows through the closed loop coil 1 and a magnetic flux is generated. The direction of this magnetic flux is
Since the magnetic flux is generated in the opposite direction to the magnetic flux generated from the inside, the magnetic fluxes cancel each other to reduce the magnetic field.

That is, when the magnetic flux generated from the electric components inside the refrigerator R1 passes through the closed loop coil 1, an induced electromotive force is generated in the closed loop coil 1 by the above-described law of electromagnetic induction, and a magnetic field is generated. The generated magnetic flux can be canceled, and leakage to the outside can be prevented.

FIG. 4 shows a refrigerator R2 equipped with a degaussing device for electric equipment according to a second embodiment of the present invention. In the present embodiment, portions having the same configuration and operation as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The degaussing apparatus for electric equipment shown in this figure is provided in the refrigerator R2 as in the first embodiment, and the closed loop coil 1 is formed into a circular or elliptical shape having a diameter of about several centimeters, for example. Are arranged on the whole surface of the housing 2. According to such a configuration, the refrigerator R
Each of the closed-loop coils 1 is arranged such that various magnetic fluxes generated from various electric components provided inside 2, that is, all the magnetic fluxes generated from the installation sites of the plurality of electric components pass through the closed-loop coil 1. Thus, the magnetic field can be reliably canceled by each closed loop coil 1.

FIG. 5 shows a refrigerator R3 equipped with a degaussing device for electric equipment according to a third embodiment of the present invention. In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. The degaussing device for electric equipment shown in this figure is mounted on the refrigerator R3 as in the above-described embodiments, and three closed-loop coils 1a, 1b, 1c are arranged on orthogonal surfaces in a three-dimensional coordinate system. These closed-loop coils 1a, 1b, 1c are connected to the front and rear of the housing 2 of the refrigerator R3 by the respective coils 1a, 1b, 1c.
It is arranged so as to surround the left, right, top and bottom. 3 is a door.

That is, one closed loop coil 1a is provided along the ZX plane of the three-dimensional coordinate system, another coil 1b is provided along the YZ plane, and another coil 1c is provided along the XY plane. The magnetic fields can be reliably canceled by 1a, 1b and 1c. Although FIG. 5 shows a case where the closed-loop coils 1a, 1b, and 1c are arranged one by one on the XY plane, the YZ plane, and the ZX plane in the three-dimensional coordinate system of the housing 2, a plurality of closed loop coils are arranged. By that
The effect of suppressing the magnetic field becomes more remarkable. Further, the closed loop coils 1a, 1b, 1c may be formed in a circular or elliptical shape having a diameter of about several centimeters as in the second embodiment, and may be combined with a method of arranging a plurality of the closed loop coils over the entire surface of the housing.

FIG. 6 shows a cross-sectional structure of a refrigerator R3 equipped with a degaussing device for electric equipment according to a fourth embodiment of the present invention. In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. The degaussing device for electric equipment shown in this figure is provided in the refrigerator R4 as in each of the above embodiments,
The closed loop coil 1 is arranged in the following manner.

That is, a heat exchanger 4, a blower fan 5, and a refrigerator 6 are provided inside the refrigerator R4, and these components are surrounded by the housing 2 and the left and right doors 3.
The space between the left and right doors 3 and the housing 2 is sealed with a gasket 7 so that cool air does not leak outside. Housing 2
A copper wire is provided inside each of the left and right doors 3, and the closed loop coil 1 is formed by connecting the gasket 7 to the copper wire with conductive rubber.

In the above configuration, the closed loop coil 1 is connected to the XY plane, YZ
Surface and the ZX surface, the closed loop coil 1 exists so as to face all surfaces of the housing 2 with respect to magnetic flux generated from the inside of the refrigerator R4. Even when a magnetic flux is generated in the direction, the magnetic flux penetrates the opposed closed loop coil 1. Therefore, an induced electromotive force is generated in the closed loop coil by the above-described electromagnetic induction,
A magnetic field is generated to cancel the magnetic flux from inside the refrigerator R4, and the effect of suppressing the magnetic field becomes more remarkable.

FIG. 7 shows a headphone Q equipped with a degaussing device for electric equipment according to a fifth embodiment of the present invention.
In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, the closed loop coils 1 are provided on the human body side (the portion corresponding to the ear) of the left and right earphones 8 of the headphones Q, respectively. In this configuration, when a magnetic flux generated from the inside of the headphone Q penetrates the closed loop coil 1, an induced electromotive force is generated in the closed loop coil 1 by the above-described electromagnetic induction, thereby generating a magnetic field and preventing the magnetic field from leaking to the outside. be able to.

In the first to fifth embodiments, the closed-loop coil 1 (or 1a, 1b, 1c; in this section, the coil 1 is listed as a representative) may be configured as described below.

By using a superconducting material as the conductive material of the closed loop coil 1, the magnetic field can be efficiently canceled.
In this case, an induced electromotive force is generated in the closed loop coil 1 by electromagnetic induction, and a current flows. The magnitude of the reverse magnetic field generated from the closed loop coil 1 is proportional to the induced current. Therefore, if the induced current is small, the effect of suppressing the magnetic field is reduced. The magnitude of the induced current is determined by the conductor resistance of the closed loop coil 1. If the resistance value is large, a loss occurs,
The current decreases. Therefore, if a superconducting material having an extremely small resistance value as described above is used as the conductive material forming the closed loop coil 1, conductor loss is eliminated, a magnetic field can be generated efficiently, and a magnetic field from an electric device is canceled. be able to.

The closed loop coil 1 is not a single loop but a coil having a multiple loop structure. However, both ends of the coil 1 are assumed to be short-circuited. The strength of the magnetic field generated in the closed loop coil 1 is determined by the magnitude of the induced electromotive force due to the magnetic flux linking the inside of the closed loop coil 1. By the way, the relationship between the magnetic flux generation source such as the motor inside the electric equipment and the closed loop coil 1 is considered to constitute a kind of transformer, so the magnetic flux generation source is the primary coil and the closed loop coil 1 is the secondary coil. Then, e ₁ / e ₂ = n ₁ / n ₂ (2) e ₁ : voltage of magnetic flux generating source e ₂ : induced voltage of closed loop coil n ₁ : number of loops of magnetic flux generating source n ₂ : the number of loops of the closed-loop coil. In order to increase the induced electromotive force e ₂ , it is necessary to increase the number of loops of the closed-loop coil 1.
It is clear from (2). Thus, the number of loops of the closed loop coil 1 is increased, the induced electromotive force is increased, the generated magnetic field in the opposite direction is increased, and the magnetic field from the magnetic flux generation source inside the electric device is canceled.

FIG. 8 shows a longitudinal section of an electric rice cooker provided with a degaussing device for electric equipment according to a sixth embodiment of the present invention. In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, as shown in FIG. 8, a layered closed loop coil 1 is formed by applying a conductive paint to a rice cooker housing 9 and a lid 10 having complicated shapes.

Although not shown, the housing 9 and the lid 1 are not shown.
Reference numeral 0 denotes a structure in which the conductive paint layers applied at the hinge attachment portion and the lock portion are connected to each other. Rice cooker housing 9
When the magnetic flux generated from the coil passes through the closed loop coil 1, an induced electromotive force is generated in the closed loop coil 1 by the above-described electromagnetic induction, thereby generating a magnetic field and preventing the magnetic field from leaking to the outside. As described above, by forming the closed loop coil 1 from the conductive paint layer, the closed loop coil 1 can be easily and inexpensively formed even in an electric device having a complicated shape of resin molding.

In the configuration shown in FIG. 8, even when the closed loop coil 1 is formed of a conductive plating layer, it is suitable for providing a housing 9 having a complicated shape and a wide closed loop coil 1. Thus, the closed loop coil 1 can be formed more easily and at lower cost.

FIGS. 9 and 10 show a degaussing apparatus for electric equipment according to a seventh embodiment of the present invention and a refrigerator provided with the degaussing apparatus. As shown in the main block diagram of FIG. 9, the degaussing apparatus of the present embodiment is a closed loop coil 11a, 11b made of a conductor that covers a magnetic field generation source provided in the housing 2 and the door 3 of the refrigerator R5 as an electric device. , 11c
And current generating circuits 12a, 12b, 12c for supplying a current to each of the closed loop coils 11a, 11b, 11c.
A generated magnetic field detecting unit 13 for detecting the intensity and direction of a magnetic field generated inside the refrigerator R5; and a magnitude of a current flowing to each of the current generating circuits 12a, 12b, and 12c in response to a signal from the generated magnetic field detecting unit 13. And a current control unit 14 for controlling the direction.

Inside the refrigerator R5 shown in FIG. 10, a compressor for compressing a built-in refrigerant for cooling the inside of the refrigerator is provided.
Various electric components (not shown) such as an internal fan motor for circulating cool air in the refrigerator, control circuit components for controlling various functions, and a surface heater for preventing dew condensation in the freezer are provided.

Each of the electric components housed in the refrigerator R5 serves as a magnetic field generating source for generating a magnetic flux when driven. In this embodiment, the upper surface corresponding to the XY plane of the housing 2, the YZ plane, The above-described closed loop coil 1 extends over both sides corresponding to the surface and a plurality of doors 3 corresponding to the ZX surface.
1a, 11b, and 11c are provided, and these closed-loop coils 11a, 11b, and 11c are configured to surround the component serving as the magnetic field generation source. Also,
The current generating circuits 12a, 12b, 12c are provided for each of the closed loop coils 11a, 11b, 11c.

Magnetic flux is generated from each of the electric components, and the magnitude and direction of the magnetic flux are determined by the generated magnetic field detecting unit 1.
3, and based on the detection signal of the generated magnetic field detection unit 13, the current control unit 14 generates the magnetic field in the closed loop coils 11a, 11b, 11c in the direction of canceling the generated magnetic field so as to generate the magnetic field. A command signal is given to 12c. Each current generating circuit 12a, 12b, 12c
Receives the command signal and operates the corresponding closed loop coil 11
a, 11b, and 11c. Therefore, the magnetic field generated by the closed loop coils 11a, 11b, 11c cancels out the magnetic flux generated from the electric components housed inside the refrigerator R5, and prevents the leakage of the magnetic flux to the outside.

That is, the conductor closed loop coils 11a, 11b, 11c are arranged so as to cover the housing 2 of the refrigerator R5 or the internal electric components for generating a magnetic field, and current flows through the closed loop coils 11a, 11b, 11c. As a result, a magnetic field H is generated. These closed loop coils 11a, 11
The strength of the magnetic field generated at the center of b, 11c is given by the following equation:
As shown in (3), H = n ₁ * I / 2r (3) H: magnetic field strength [A / m] n ₁ : number of loops of closed loop coil I: closed loop coil Flowing loop current [A] r: loop radius [m] of the closed loop coil, and the direction of the generated magnetic field occurs in the right-handed screw direction in which the current flows. Then, the magnetic field H generated from inside the refrigerator R5 causes the closed loop coils 11a, 11b, 11
The current is caused to flow so that the magnetic field generated by c is generated in the opposite direction with the same strength, thereby canceling each other and reducing the magnetic field.

When the generated magnetic field detecting unit 13 is provided inside the refrigerator R5, the magnetic field near the door 3 is estimated from the magnitude and direction of the generated magnetic field, and the magnetic field is applied to the closed loop coil 11b of the door. The error is likely to occur because the current is controlled so as to cancel the error.

Therefore, the generated magnetic field detecting unit 13 is provided on the operation surface side where the user comes closest to the electric equipment, or on the door 3 in the case of the refrigerator R5 (not shown). With this configuration, the magnetic field generated from the inside of the refrigerator R5 is transmitted to the refrigerator R5.
5 can be accurately detected at a place where the user approaches, so that the accuracy of the degaussing control near the door can be increased, and the influence of the magnetic field on the human body can be reduced more accurately.

FIGS. 11 to 14 show a refrigerator R6 equipped with a degaussing device for electric equipment according to an eighth embodiment of the present invention. In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. FIG. 11 is a main block diagram showing closed loop coils 11d, 11e, 11f, 11g, 11h, and 11i.
And current generating circuits 12d, 12e, 12f, 12g, 12h, 1 for flowing a current through each of the closed loop coils 11d to 11i.
2i, and generated magnetic field detectors 13d, 13e, 13f, 13g, 13h, 13i for detecting the strength and direction of a magnetic field generated from inside the refrigerator R6 and leaking from each surface to the outside,
Current control units 14d, 14e, 14f, 14g, which control the magnitude and direction of the current flowing through each of the current generation circuits 12d to 12i in response to the signals from the generated magnetic field detection units 13d to 13i.
14h and 14i.

FIG. 12 schematically shows the arrangement of the closed loop coils 11d to 11i. As shown in this figure, the closed loop coils 11d to 11i are connected to the XY plane of the refrigerator R6, YZ.
The housing 2 and the door 3 are provided so as to surround the surface and the ZX surface. The conductor constituting the closed loop coils 11d to 11i uses a copper wire having a small electric resistance. Although not shown, the generated magnetic field detection units 13d to 13i are arranged outside the closed loop coils 11d to 11i.

FIG. 13 shows a cross-sectional structure of the refrigerator R6. Here, the arrangement of the closed loop coil 11i will be described. Inside the refrigerator R6, a heat exchanger 4, a blower fan 5,
A refrigerator compartment 6 is provided, and these components are surrounded by a housing 2 and left and right doors 3. The left and right doors 3
A gasket 7 is provided between the housing 2 and the housing 2 so that cold air does not leak outside. A copper wire is provided inside each of the housing 2 and the left and right doors 3, and a closed loop coil 11i is formed by connecting the gasket 7 to the copper wire with conductive rubber.

In the above configuration, the degaussing control process will be described with reference to the flow chart of FIG. 14. Each closed loop coil 11d to 11i, the current generating circuit 1
The 2d to 12i, the generated magnetic field detection units 13d to 13i, and the current control units 14d to 14i control each independently. That is, in step # 1, the generated magnetic field detection units 13d to 13i
Detects the direction and magnitude of the magnetic field leaking from the surface. If the leakage magnetic field is not 0 in step # 2, the current controllers 14d to 14i generate a magnetic field for canceling the leakage magnetic field in the closed loop coils 11d to 11i via the current generating circuit in step # 3. By repeating this control, the leakage magnetic field can be controlled to zero. Therefore, the effect of suppressing the magnetic field becomes significant.

FIG. 15 shows a refrigerator R7 equipped with a degaussing device for electric equipment according to a ninth embodiment of the present invention.
In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. In the above embodiment, the XY plane, the YZ plane of the refrigerator R7,
The case where the closed loop coils 11d to 11i are provided so as to surround the ZX plane has been described. For example, as shown in FIG. 15, the closed loop coil 11j is provided outside the magnetic field generating component (not shown) inside the refrigerator R7. At the same time, the closed loop coil 11k is arranged in the door portion where the user approaches.
Thus, it is also effective to dispose the closed loop coils 11j and 11k only in the portion where the leakage magnetic field is desired to be suppressed, and to demagnetize. In this case, the closed loop coils at unnecessary portions can be omitted. , And can be configured at a lower cost.

In the seventh to ninth embodiments,
Assuming that the closed loop coil is not a single loop but a coil having a multiple loop structure, the strength of the magnetic field generated at the center of the closed loop coil is, as is clear from equation (3),
It can be seen that when the strength of the generated magnetic field is the same, the loop current I can be reduced by increasing the number of loops of the closed loop coil. By increasing the number of loops of the closed loop coil in this way, the loop current flowing through the closed loop coil can be reduced, and the capacity of the current generating circuit flowing current through the closed loop coil can be reduced.
Therefore, the magnetic field from the magnetic flux generation source inside the refrigerator R5 can be canceled with a small loop current.

FIG. 16 shows a longitudinal section of an electric rice cooker equipped with a degaussing device for electric equipment according to a tenth embodiment of the present invention. In the present embodiment, portions having the same configuration and operation as those of the above embodiments are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, as shown in FIG.
A layered closed loop coil 11 is formed by applying a conductive paint to the rice cooker housing 9 and the lid 10 having a complicated shape. Although not shown, the housing 9 and the lid 10 are not shown.
Has a structure in which the conductive paint layers applied at the hinge attachment portion and the lock portion are connected to each other.

A magnetic field generated from the rice cooker housing 9 is detected by a generated magnetic field detection unit (not shown), and a current control unit (not shown) is connected to the closed loop coil 1 via a current generation circuit 12.
Then, an opposite magnetic field of the same strength is generated. Therefore, it is possible to prevent the magnetic field from leaking to the outside. In this way, by forming the closed loop coil 11 from the conductive paint layer, the closed loop coil 11 can be easily and inexpensively formed even in an electric device having a complicated shape of resin molding.

In the configuration shown in FIG.
Even if the closed loop coil 11 is formed by a plating layer having conductivity, it is suitable for providing a housing having a complicated shape and a wide closed loop coil 11, and the closed loop coil 11 can be formed more easily and inexpensively. Can be.

In each of the above embodiments, the refrigerators R1 to R
Although the degaussing device for refrigerator or the degaussing device for headphone and electric rice cooker provided with a closed loop coil made of a conductor covering the 6 is illustrated, the degaussing device for electric device of the present invention is used for refrigerator, headphone or electric rice cooker. However, the present invention is not limited to this, and can be applied to any of the electrical devices listed below.

That is, the electric equipment to which the present invention can be applied includes a refrigerator, a washing machine, an air conditioner indoor unit, an air conditioner outdoor unit, a vacuum cleaner, a clothes dryer, a microwave oven, an electromagnetic cooker, an electric hot plate, and an electric appliance. Pots, dish dryers, dehumidifiers, air purifiers, electric heaters, oil fan heaters, hair dryers, lighting fixtures, multifunctional toilet seats for hot water, heating and deodorization, AC adapters, chargers, personal computers, word processors, work Computers such as stations, computers with display devices such as notebook computers, calculators, portable information tools, copiers, scanners, printers, video printers, electronic cash registers, CD players, MD players, tape recorders, tuners,
Examples include a speaker, a system audio, a telephone (including a cordless telephone handset and a mobile phone), a facsimile, a video camera (including a video camera with a display function), an electronic still camera, a display, a television, and a projection projector device. .

[0058]

As described above, the present invention has the following effects. That is, according to claim 1,
Since the degaussing device is constituted by a closed loop coil made of a conductor, which surrounds the housing of the electric device or the magnetic field generation source attached to the electric device, it is possible to minimize the leakage of the magnetic field generated by the electric device to the outside. Video and
This can be an effective noise prevention measure for audio electric products, and can prevent the influence of a magnetic field on the human body.

According to the present invention, a closed loop coil made of a conductor for covering a housing of an electric device or a magnetic field generation source attached to the electric device, and a current generating circuit for supplying a current to the closed loop coil. A generated magnetic field detection unit that detects the intensity and direction of a magnetic field generated inside the electric device,
A current control unit that controls the magnitude and direction of the current flowing through the closed loop coil in response to the magnetic field detection signal from the generated magnetic field detection unit, so that the magnetic field generated by the electric device leaks to the outside Can be reduced as much as possible,
In addition, it can be a noise prevention measure for video and audio electrical products, and can prevent the influence of a magnetic field on the human body.

According to the third aspect of the present invention, a relatively simple structure in which the closed loop coil is formed in a plural-turn loop structure can effectively cancel out a magnetic field generated from an electric device and reduce a leakage magnetic field.

According to the fourth aspect, since the closed loop coil is formed by fixing a conductive material in a layered manner on the housing of the electric equipment, it is inexpensive and can be installed even in a place having a complicated shape. It can be.

According to the fifth aspect, the closed-loop coil is provided so as to surround the housing of the electric equipment or the front, rear, left, right, and upper and lower sides of the magnetic field generation source attached to the electric equipment, so that the magnetic field to the outside is provided. Leakage can be further reduced.

According to the sixth aspect, in the configuration of the second aspect, since the generated magnetic field detecting section is provided on the operation surface side of the electric device, it is possible to measure the magnetic field at a place closer to the human body, The leakage magnetic field to the human body can be reliably reduced.

In summary, according to the present invention, a closed loop coil is provided to cover the entire electric device (magnetic field generation source), or the closed loop coil is provided with respect to the closed loop coil so that an external leakage magnetic field is minimized. By controlling the flow of electric current, the leakage magnetic field can be reduced, and the leakage magnetic field of the entire electric device can be reduced. Therefore, a degaussing coil is provided for each magnetic field source (motor, heater, etc.), and each drive current is Compared with a conventional magnetic field reduction device that passes a synchronized current, the number of closed loop coils can be reduced, and the influence of the magnetic field can be removed at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a degaussing principle according to a first configuration of the present invention.

FIG. 2 is an explanatory diagram of a demagnetizing principle according to a second configuration of the present invention.

FIG. 3 is a perspective view showing an arrangement structure of a closed loop coil according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing an arrangement structure of a closed loop coil according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing an arrangement structure of a closed loop coil according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing the structure of a closed loop coil inside a refrigerator according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing an arrangement structure of a closed loop coil inside a headphone according to a fifth embodiment of the present invention.

FIG. 8 is a sectional view showing an arrangement structure of a closed loop coil inside an electric rice cooker according to a sixth embodiment of the present invention.

FIG. 9 is a main block diagram showing a seventh embodiment of the present invention.

FIG. 10 is a perspective view showing an arrangement structure of the closed loop coil and the current generation circuit.

FIG. 11 is a main block diagram showing an eighth embodiment of the present invention.

FIG. 12 is a perspective view showing an arrangement structure of the closed loop coil and the current generation circuit.

FIG. 13 is a sectional view showing the structure of a closed loop coil inside the refrigerator.

FIG. 14 is a flowchart showing a degaussing control process.

FIG. 15 is a sectional view showing the structure of a closed loop coil inside a refrigerator according to a ninth embodiment of the present invention.

FIG. 16 is a sectional view showing an arrangement structure of a closed loop coil inside an electric rice cooker according to a tenth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 closed loop coil 2 housing 3 door 8 earphone 9 rice cooker housing 10 lid 11 a to 11 k closed loop coil 12 a to 12 i current generation circuit 13, 13 d to 13 i generated magnetic field detection unit 14, 14 d to 14 i current control unit R 1 to R 7 refrigerator

Claims (6)

[Claims] 1. A degaussing device for an electric device, comprising a closed loop coil made of a conductor, surrounding a housing of the electric device or a magnetic field generation source attached to the electric device. 2. A closed loop coil made of a conductor for covering a housing of an electric device or a magnetic field generating source attached to the electric device, a current generating circuit for supplying a current to the closed loop coil, and an internal portion of the electric device. A generated magnetic field detection unit that detects the strength and direction of a magnetic field generated in the magnetic field, and a current control unit that controls the magnitude and direction of a current flowing through the closed loop coil in accordance with a magnetic field detection signal from the generated magnetic field detection unit. A degaussing device for electrical equipment, comprising: 3. The degaussing apparatus for an electric device according to claim 1, wherein the closed loop coil is formed in a multi-turn loop structure. 4. The degaussing apparatus for an electric device according to claim 1, wherein the closed loop coil is formed by fixing a conductive material in a layered manner on a housing of the electric device. 5. The electric device according to claim 1, wherein the closed-loop coil is provided so as to surround a housing of the electric device or a magnetic field generation source attached to the electric device before and after, right and left, and up and down. Degaussing device. 6. The degaussing device for an electric device according to claim 2, wherein the generated magnetic field detection unit is provided on an operation surface side of the electric device.