JP2002199412A - Degaussing coil device and cathode-ray tube having the degaussing coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a degaussing coil device that can increase desired cancellation magnetic field, without the need for increasing the number of turns of a degaussing coil, facilitate forming of the mount shape and the mount work and reduce the cost of the degaussing coil, and to provide a cathode-ray tube having the degaussing coil. SOLUTION: This invention provides the cathode-ray tube which has the degaussing coil where a loop coil 11, formed by winding a single conductor wire by a plurality of times is twisted by about 180 degrees by two twisted parts 13a, 13b to form a 1st loop section 12a, a 2nd loop section 12b and a 3rd loop section 12c, the 1st and 2nd loop sections 12a, 12b are respectively bridged over a panel section 16 and a funnel section 17 of the cathode-ray tube 15, on which a shadow mask 16 and inner shields 20 are laid out, facing each other, and the 3rd loop section 12c is fitted to the funnel section 17 at which the ends of the inner shields 20 are placed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CRT having at least a shadow mask and an inner shield, and to a degaussing coil device for demagnetizing magnetism magnetized on the shadow mask and the inner shield, and a CRT having a degaussing coil.

[0002]

2. Description of the Related Art In general, a color CRT is used in video equipment such as a color television receiver and a color monitor for reproducing and displaying video and information based on video signals and various information signals.

In a color cathode ray tube, an electron beam projected from an electron gun is accurately projected on a phosphor via a shadow mask.

[0004] The shadow mask is formed of a thin metal plate and is magnetized under the influence of geomagnetism. In order to prevent the influence of geomagnetism on the shadow mask, a magnetic shield plate called an inner shield is mounted inside the funnel portion of the cathode ray tube.

However, the cathode ray tube having the shadow mask and the inner shield is not prevented from being magnetized by terrestrial magnetism. When the color television receiver or the color monitor device is moved, the shadow mask or the inner shield is magnetized. The electron beam is affected,
A convergence shift, which is a color shift, occurs.

Accordingly, in order to eliminate the magnetization of the shadow mask and the inner shield of the cathode ray tube, a coil (hereinafter referred to as a degaussing coil) is provided outside the glass tube in the funnel portion where the shadow mask and the inner shield of the cathode ray tube are disposed. ) Is attached, and an alternating current that decays with time is applied to this coil to demagnetize the coil.

The shape of the degaussing coil and the state of attachment to the cathode ray tube will be described with reference to FIGS. FIG. 4A is a rear view showing a state where a single degaussing coil is attached to a CRT, and FIG. 4B is a cross-sectional view showing a state where a single degaussing coil is attached to a CRT. FIG. 5A is a rear view showing a state where two degaussing coils are attached to a CRT, and FIG. 5B is a cross-sectional view showing a state where two degaussing coils are attached to a CRT.

First, a description will be given with reference to FIG. The CRT 15 includes a panel section 16, a funnel section 17, and a neck section 18. On the inner surface of the panel section 16, phosphors of three primary colors (not shown) are applied in a predetermined order at predetermined intervals. Further, a shadow mask 19 is mounted and disposed at a predetermined interval from the surface of the panel portion 16 on which the phosphor is applied. An inner shield 20 which is in contact with or is connected to both ends of the shadow mask 19 is mounted on the inner surface of the funnel 17. An electron gun (not shown) is mounted on the neck portion 18, and the electron beam projected from the electron gun strikes the phosphor applied to the panel portion 16 through the shadow mask 19 to emit light. .

On the other hand, the degaussing coil 41 is formed in a substantially rectangular shape by winding a single conductive wire a plurality of times. The upper side 41b of the degaussing coil 41 is attached near the connection between the shadow mask 19 and the inner shield 20 which are mounted and arranged inside the joint between the upper part of the panel part 16 and the upper part of the funnel part 17 of the cathode ray tube 15, The lower side 41a of the degaussing coil 41 is attached near the end of the inner shield 20 inside the funnel 17 of the cathode ray tube 15. Both sides of the degaussing coil 41 are obliquely attached to the funnel 17 of the cathode ray tube 15.

The coil start 41x and the coil end 41 of the degaussing coil 41 attached to the cathode ray tube 15
When an alternating current I4 that attenuates with time is supplied to y, in a half cycle of the alternating current I4, for example, a magnetic field m4 indicated by a dotted arrow in the drawing is generated in the lower side 41a of the degaussing coil 41, and an upper side 41b is formed in the upper side 41b. A magnetic field m5 indicated by a dotted arrow is generated. The directions of the generated magnetic fields are different from each other, and the magnetic field between the upper side portion 41b and the lower side portion 41a causes the shadow mask 19 and the inner shield 2 to move.
Zero demagnetization is performed.

In general, the degaussing coil 41 includes two conductive wires.
It is wound about 0 to 50 times, and the wound conductive material is bundled with insulating vinyl or the like to form a substantially rectangular shape, and attached and fixed to the cathode ray tube 15 as described above.

The strength (unit AT) of the magnetic field generated from the degaussing coil 41 is set by the product of the number of turns N of the coil and the current value I (AT = NI). Therefore, in order to obtain a large degaussing effect, it is necessary to increase the number of turns N of the degaussing coil 41 or increase the current value I.

However, when the number of turns N of the degaussing coil 41 is increased, the diameter of the degaussing coil 41 becomes large, and it becomes difficult to form and attach and fix the cathode ray tube 15. Further, in order to increase the supply current value I, the resistance value at normal temperature provided in the degaussing current supply circuit that supplies an alternating current to the degaussing coil 41 is low, and the temperature rises with the passage of time and the resistance value increases. It is necessary to use an increasing positive thermistor resistance with a smaller resistance at room temperature. However, the positive thermistor resistor at room temperature has a considerably small value at room temperature, and a device capable of increasing the supply current by further reducing the resistance value cannot be expected.

For this reason, as shown in FIG. 5, a shadow mask 19 near the upper and lower portions of the panel portion 16 of the cathode ray tube 15 is provided.
A first degaussing coil 51a and a second degaussing coil 51b are attached to the inner shield 20 of the funnel 17 and the inner shield 20. The coil end 51x of the first degaussing coil 51a and the coil starting end 51y of the second degaussing coil 51b
And the coil starting end 5 of the first degaussing coil 51a.
1w and the coil end 51z of the second degaussing coil 51b are connected in series so that a degaussing current is supplied.
However, the first degaussing coil 51a and the second degaussing coil 5
The winding direction of the conductive wire 1b, that is, the direction of the degaussing current, is differently connected.

A half cycle of the degaussing current I5 supplied from the coil starting end 51w of the first degaussing coil 51a.
Flows through the first degaussing coil 51a as indicated by an arrow in the drawing, and as shown in FIG. 5B, a magnetic field m7 is generated near the panel section 16 of the cathode ray tube 15, and a magnetic field m6 is generated in the funnel section 17. Occurs. The current I5 flowing through the first degaussing coil 51a flows in the second degaussing coil 51b as a current I6 as shown by an arrow in the figure, and as shown in FIG. A magnetic field m7 'is generated in the vicinity, and a magnetic field m6' is generated in the funnel section 17.
The shadow mask 19 and the inner shield 2 are formed by the combined magnetic field of the respective magnetic fields m6, m7, m6 ', and m7' generated by the first and second degaussing coils 51a and 51b.
Zero demagnetization is performed.

That is, the two degaussing coils 51a and 51b
The demagnetizing magnetic field is increased by synthesizing the magnetic fields generated in step (1).

[0017]

Conventionally, the shadow mask and inner shield of a cathode ray tube are magnetized by the influence of terrestrial magnetism. For this reason, various video equipment such as a television receiver and a color monitor using a cathode ray tube are provided with a degaussing coil on the cathode ray tube in order to eliminate color shift caused by convergence due to the magnetization of the shadow mask and the inner shield. When the operation power supply is turned on, an alternating current that decreases with time is supplied to the degaussing coil, and the magnetic field generated by the degaussing coil demagnetizes the shadow mask and the inner shield.

On the other hand, the cathode ray tube has a large screen size, and it is necessary to apply a strong demagnetizing field to demagnetize the magnetization of the shadow mask and the inner shield.

However, it cannot be expected that the resistance value of the positive thermistor element used in the degaussing current supply circuit for supplying the degaussing current at room temperature becomes smaller than that at present. For this purpose, the number of turns of the degaussing coil is increased, or the degaussing coil is divided into two to increase the degaussing magnetic field by the combined magnetic field.

When the number of turns of the degaussing coil is increased as described above,
There has been a problem that the diameter of the degaussing coil becomes large, and it is difficult to form and attach the degaussing coil to a shape to be attached to a cathode ray tube.

When the degaussing coil is divided into two, the degaussing field increases. However, when a stronger degaussing field is required, the number of turns of the two degaussing coils increases, and the diameter of each degaussing coil becomes large. However, there has been a problem that the molding into the shape to be attached to the cathode ray tube and the attaching operation become difficult.

Further, when the number of turns of the degaussing coil is increased, the required amount of the conductive wire is increased, which causes a problem that the cost is increased.

In view of the above problems, the present invention increases the desired demagnetizing field without increasing the number of turns of the degaussing coil, and facilitates forming and mounting work of the mounting shape, and
An object of the present invention is to provide a degaussing coil device capable of reducing the cost of a degaussing coil and a CRT device having the degaussing coil.

[0024]

According to the demagnetizing coil device of the present invention, a single conductive wire is wound a plurality of times to form three substantially rectangular loop coils, and these three loop coils are arranged in a cathode ray tube. In addition, a demagnetizing magnetic field is generated by a degaussing current supplied to the three loop coils.

The three loop-shaped coils of the degaussing coil device of the present invention are formed by winding a single conductive wire into a loop a plurality of times and forming a single loop coil of approximately 18 at two twisted portions.
It is characterized by comprising a first loop portion and a second loop portion formed at both ends of the twisted portion, and a third loop portion formed between the twisted portions.

The first loop portion and the second loop portion of the three loop-shaped coils of the degaussing coil device of the present invention have inner shields arranged from the end of the panel portion where the shadow mask of the CRT is arranged. And a third loop portion is disposed on a funnel portion where an end of the inner shield is disposed.

The three loop-shaped coils of the degaussing coil device according to the present invention include first, second, and third loop coils each formed by winding a single conductive wire in a loop a plurality of times; The first to third loop coils are connected in series so that demagnetizing currents in the same direction are supplied at portions close to each other.

The first loop coil and the second loop coil of the three loop coils of the degaussing coil device of the present invention are:
The end portion of the panel portion where the shadow mask of the cathode ray tube is disposed is placed opposite to the funnel portion where the inner shield is disposed, and the third loop coil is disposed at the end portion of the inner shield. It is characterized in that it is arranged in a funnel part.

According to the degaussing coil device of the present invention, a large demagnetizing field can be obtained with a small number of windings by the combined magnetic field of the magnetic fields generated by the three loop coils, and the degaussing field is reduced by the shadow mask of the cathode ray tube and the inner shield. To work efficiently, and reliable demagnetization became possible. In addition, since the degaussing coil can be generated with a small number of windings, the efficiency of forming and mounting the degaussing coil can be improved.

Further, the CRT device having the degaussing coil of the present invention has a degaussing coil composed of three substantially rectangular loop-shaped coils formed by winding a single conductive wire a plurality of times, and at least a shadow mask and an inner shield. A cathode ray tube, and two loop-shaped coils of the degaussing coil are attached and fixed to face each other from the end of the panel portion where the shadow mask of the cathode ray tube is arranged to the funnel portion where the inner shield is arranged. Another one
The two loop-shaped coils are attached and fixed to a funnel portion where the end of the inner shield is arranged.

The degaussing coil of the cathode ray tube device having the degaussing coil of the present invention is formed by winding a single conductive wire in a loop a plurality of times and twisting one loop coil by about 180 degrees at two twisted portions. First formed on both ends of the twisted part
And a third loop portion formed between the twisted portions, wherein the first and second loop portions are formed by a panel portion on which a shadow mask of a cathode ray tube is arranged. From the end of the inner shield is fixed to the funnel where the inner shield is disposed, and the third loop of the degaussing coil is fixed to the funnel where the end of the inner shield is disposed. Features.

The degaussing coil of the CRT device having the degaussing coil according to the present invention comprises first, second and third loop coils formed by individually winding a single conductive wire in a loop a plurality of times, The first and second loop coils are fixed to face each other from the end of the panel portion where the shadow mask of the cathode ray tube is disposed to the funnel portion where the inner shield is disposed, and the third loop of the degaussing coil is fixed. The coil was attached and fixed to the funnel portion where the end of the inner shield was disposed, and the first to third loop coils were connected in series so that a demagnetizing current in the same direction was supplied at a portion adjacent to each other. It is characterized by the following.

According to the CRT device having the degaussing coil of the present invention, a large demagnetizing field is applied to the shadow mask and the inner shield of the CRT by the combined magnetic field of the magnetic fields generated by the three loop coils without increasing the number of windings. It was able to operate efficiently, and reliable demagnetization became possible. In addition, since the degaussing coil can be generated with a small number of windings, the efficiency of forming the degaussing coil and attaching the degaussing coil to the CRT was improved.

[0034]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a degaussing coil device according to the present invention, and FIG.
FIG. 1B is a cross-sectional view illustrating a state in which the degaussing coil device is mounted on the cathode ray tube. FIG. 2 is an explanatory diagram illustrating a forming process of an embodiment of the degaussing coil device according to the present invention.

First, a description will be given with reference to FIG. FIG. 2 (a)
As shown in (1), a substantially rectangular loop-shaped coil 11 having a number of turns of, for example, 20 to 50 is formed using a single conductive wire. This loop-shaped coil 11
Is formed to have a shape and dimensions substantially equal to the horizontal size of the cathode ray tube 15 in the horizontal direction in the figure, and the vertical size L in the figure is formed to be larger than the horizontal shape and size. Note that reference numeral 11a in the figure is the starting end of the loop coil 11, and reference numeral 1
Reference numeral 1b denotes an end of the loop coil, and a demagnetizing current supply circuit (not shown) is connected between the start end 11a and the end 11b.

This one loop-shaped coil 11 is shown in FIG.
As shown in (b), the vertical dimension L is approximately 3
The second loop portion 12b and the second torsion portion 13b are formed by twisting about 180 degrees at the 1 / (L / 3) portion. Next, about one third (L / L) of the loop-shaped coil 11 from below in the figure.
The first loop portion 12a and the first twist portion 13a are formed by twisting about 180 degrees in the portion 3). The first twisted portion 13a
The third loop portion 12 is provided between the third loop portion 12 and the second torsion portion 13b.
c can be formed.

That is, the first coil portion 12a and the second loop portion 12 are formed by twisting the loop-shaped coil 11 at about 180 degrees at two points, which are about one third of the longitudinal dimension L.
b, and the degaussing coil 10 having three loops of the third loop portion 12c can be formed.

Thus, one loop-shaped coil 11
The degaussing coil 10 formed into a shape having three loop portions 12a, 12b, and 12c is attached and fixed to the cathode ray tube 15.

The attachment of the degaussing coil 10 to the cathode ray tube 15 will be described with reference to FIG. The neck portion 1 is connected to the third loop portion 12c from the neck portion 18 side of the cathode ray tube 15.
8 and inserted into the funnel 17. Next, a side of the first loop portion 12a facing the first twisted portion 13a is a panel portion 16 of the cathode ray tube 15 at a lower portion in the drawing.
And a side of the second loop portion 12b facing the second torsion portion 13b is attached near a boundary between the second loop portion 12b and the funnel portion 17.
The cathode ray tube 15 is mounted near the boundary between the panel portion 16 and the funnel portion 17 in the upper part of the drawing.

That is, the side of the first loop portion 12a facing the first twisted portion 13a is attached to the portion where one end of the shadow mask 19 and the inner shield 20 are located, and the second loop portion 12b Of the second torsion part 13
The side portion facing “b” is attached to the portion where the other ends of the shadow mask 19 and the inner shield 20 are located. First torsion portion 1 forming third loop portion 12c
The 3a and the second twisted portion 13b are mounted and attached to a portion of the neck portion 18 where the end of the inner shield 20 is located.

When a degaussing current is supplied to the degaussing coil 10 attached to the cathode ray tube 15 between the coil starting end 11a and the terminal end 11b, the coil is supplied from the coil starting end 11a in a half cycle in which the degaussing current is present. The current I1 flows through the first loop portion 12a in the direction of the arrow in the figure,
This current I1 flows in one current path of the first twisted portion 13a in the direction of the current I2. This current I2 is applied to the second twisted portion 1
3b flows in one current path in the direction of the current I3. This current I
3 flows through the second loop portion 12b in the direction of the current I4.
This current I4 flows in the direction of the current I5 through the other electric path of the second twisted portion 13b. This current I5 is applied to the first twisted portion 1
3a flows in the direction of the current I6 through the other electric circuit. This current I
6 flows through the first loop portion 12a in the direction of the current I7 and returns from the coil end 11b to the degaussing current supply circuit. In the next half cycle of the degaussing current, the degaussing coil 1
Flows through zero.

That is, the first twisted portion 13a has
The current I2 flowing from the first loop portion 12a to the third loop portion 12c and the current I6 flowing from the third loop portion 12c to the first loop portion 12a are in the same direction, and
From the third loop portion 12c flowing to the torsion portion 13b
Current I3 flowing in the loop portion 12b of the second loop portion 1
The current I5 flowing from 2b to the third loop portion 12c is in the same direction.

For this reason, as shown in FIG. 1B, the magnetic field m2 generated by the first twisted portion 13a and the second twisted portion 1
The magnetic field direction is different from the magnetic field m3 generated in 3b,
The magnetic field m1 on the side of the first loop portion 12a facing the first torsion portion 13a and the magnetic field m4 on the side of the second loop portion 12b facing the second torsion portion 13b have different directions. A magnetic field is created. These magnetic fields m1, m2,
The shadow mask 1 is generated by the combined magnetic field of m3 and m4.
9 and the inner shield 20 are efficiently demagnetized. That is, the first to third loop portions 12a, 1
2b and 12c are the same number of turns, and are supplied with the same value of current.
The magnetic fields NI (AT) generated at 12b and 12c are equal, and the combined magnetic field applied to the shadow mask 16 and the inner shield 20 is a triple magnetic field (3NI = AT).

As a result, when a demagnetizing current of the same value is supplied with the same number of coil windings as in the prior art, a triple demagnetizing magnetic field can be obtained. In addition, since the first to third loop portions 12a, 12b, 12c can be attached to the end portions of the shadow mask 19 and the inner shield 20 of the cathode ray tube 15, the demagnetizing field can be efficiently demagnetized. . Further, the degaussing coil 10 is formed by twisting one loop-shaped coil 11 at two places by about 180 degrees.
Since the two loop portions 12a, 12b, and 12c can be generated, the shape forming and mounting work for mounting on the CRT 15 can be simplified.

Next, another embodiment of the degaussing apparatus according to the present invention will be described with reference to FIG. FIG. 3A shows another embodiment of the degaussing coil device according to the present invention. FIG. 3A is a rear view showing a state in which the degaussing coil is mounted on a cathode ray tube, and FIG. FIG. 3C is a cross-sectional view illustrating a state in which the coil is mounted on the cathode ray tube, and FIG. 3C is an explanatory diagram illustrating a forming process of another embodiment of the degaussing coil device according to the present invention.

First, the degaussing coil 31 will be described with reference to FIG.
The generation process of the first to third loop coils 31a, 31a, having the same number of windings using the same single conductive wire will be described.
31b and 31c are individually formed. The individually formed first to third loop coils 31a, 31b, 31c
Is formed in a substantially rectangular loop shape having a lateral dimension substantially equal to at least the lateral dimension of the cathode ray tube 15. The coil end 32b of the individually formed first loop coil 31a is connected to the coil start end 33a of the third loop coil 31c. The coil end 33b of the third loop coil 31c is connected to the coil start end 34a of the second loop coil 31b. The first loop coil 31
a coil start end 32a and the second loop coil 31b
Is connected to a demagnetizing current supply circuit (not shown). The third loop coil 31c has a different winding direction from the first and second loop coils 31a and 31b, and the first to third loop coils 31a, 31b and 31c are connected in series. Connecting.

The three loop coils 31a, 3
As shown in FIGS. 3A and 3B, the degaussing coil 31 formed by connecting the series loops 1b and 31c is arranged so that the third loop coil 31c is inserted through the neck portion 18 of the cathode ray tube 15 from the neck portion 18 side. The first and second loop coils 31a and 31b are mounted on the shadow mask 1 respectively.
9 and the end portions of the inner shield 20 are mounted on the funnel 17 from the boundary between the panel 16 at the upper and lower ends of the cathode ray tube 15 and the funnel 17. On the other hand, the third loop coil 31c is connected to the funnel 1 where the other end of the inner shield of the cathode ray tube 15 is disposed.
Attach and attach to 7 parts.

The first to third loop coils 3
After individually mounting 1a, 31b, and 31c on the cathode ray tube 15, the coil end 32b of the first loop coil 31a
And the coil start end 33a of the third loop coil 31c, the coil end 33b of the third loop coil 31c, and the coil start end 34a of the second loop coil 31b.

The first loop coil 31a of the degaussing coil 31 thus mounted on the cathode ray tube 15
The coil circuit on the side having the connection portion 33 to which the coil end 32b of the third loop coil 31c is connected to the coil start end 33a of the third loop coil 31c is close to the coil end 33b of the third loop coil 31c and the coil end of the second loop coil 31b. Coil start end 3
The coil electric circuit on the side having the connection portion 34 to which the connection portion 4a is connected is attached and mounted in close proximity.

The coil starting end 32a of the first loop coil 31a of the degaussing coil 31 and the second loop coil 31b
When a degaussing current supply circuit (not shown) is connected between the coil ends 34b, the current I1 supplied from the coil starting end 32a in one half cycle of the supplied degaussing current
1 flows through the first loop coil 31a in the direction indicated by the arrow in the figure. The current I11 flowing through the first loop coil 31a is supplied from the connection portion 33 to the third loop coil 31c, and flows as a current I12 in a direction indicated by an arrow in the drawing. The current I1 flowing through the third loop coil 31c
2 is supplied from the connection portion 34 to the second loop coil 31b, flows as a current I13 in the direction indicated by the arrow in the drawing, and returns from the coil end 34b to the degaussing current supply circuit. In the next half cycle of the degaussing current, the current flows in the direction opposite to the above.

That is, the first loop coil 31a
Currents I11 and I12 in the same direction flow through the two electric circuits near the portion having the connection portion 33 of the third loop coil 31c and the third loop coil 31c and the second loop coil 3c.
Currents I12 and I13 in the same direction flow through the two electric paths close to the portion having the connection portion 1b.

Therefore, as shown in FIG. 3 (b), a magnetic field m2 in the same direction is generated in the vicinity of the first loop coil 31a and the third loop coil 31c, and the third loop coil 31c and the second loop coil 31c In the vicinity of the loop coil 31b, a magnetic field m3 in the same direction is generated. These magnetic fields m2,
Magnetic fields m1 and m4 generated in m3 and other electric paths of the first loop coil 31a and the second loop coil 31b generate magnetic fields in different directions. These magnetic fields m1, m
With the combined magnetic field of 2, m3, and m4, the shadow mask 19 and the inner shield 20 are efficiently demagnetized.

That is, the first to third loop coils 31
a, 31b, and 31c are the same number of windings, and the magnetic field (NI = A
T) are equal, and the combined magnetic field applied to the shadow mask 16 and the inner shield 20 is 3NI = AT.

Thus, when the same demagnetizing current is supplied with the same number of coil windings as in the prior art, three times the demagnetizing magnetic field can be obtained. In addition, since the first to third loop coils 31a, 31b, 31c can be individually mounted on the ends of the shadow mask 19 and the inner shield 20 of the cathode ray tube 15, the demagnetizing field can be efficiently demagnetized. Can be. In particular, the degaussing coil 31 includes three loop coils 31a, 31b, and 31c that are individually formed and formed.
Are individually mounted at predetermined positions of the cathode ray tube 15, and then the connection between the loop coils is performed, so that the mounting operation is easier than in the above-described embodiment of the present invention, and the mounting efficiency can be further improved.

[0055]

According to the degaussing coil device of the present invention and the CRT device having the degaussing coil, a degaussing coil having three coil loops can be easily generated, and the shadow mask and the demagnetizing current value can be increased without increasing the number of coil turns and the degaussing current value. The most efficient demagnetizing force can be supplied to the inner shield. And,
It can be easily attached to a desired position on the CRT, and has the effects of improving the molding cost of the degaussing coil and improving the efficiency of the work for mounting on the CRT.

[Brief description of the drawings]

1A and 1B show an embodiment of a degaussing coil device according to the present invention. FIG. 1A is a rear view showing a state where the degaussing coil device is mounted on a cathode ray tube, and FIG. Sectional drawing which shows the state mounted | worn with.

FIG. 2 is an explanatory diagram illustrating a forming process of an embodiment of a degaussing coil according to the present invention.

3A and 3B show another embodiment of the degaussing coil device according to the present invention. FIG. 3A is a rear view showing a state where the degaussing coil device is mounted on a cathode ray tube, and FIG. FIG. 3C is a cross-sectional view showing a state in which the display is mounted on a cathode ray tube.
FIG. 4 is an explanatory diagram illustrating a forming process of the degaussing coil device.

FIG. 4 shows a conventional degaussing coil device, FIG. 4 (a) is a rear view showing a state where the degaussing coil device is mounted on a cathode ray tube, and FIG. 4 (b) is a cross section showing a state where the degaussing coil device is mounted on the CRT. FIG.

5A and 5B show a conventional degaussing coil device, FIG. 5A is a rear view showing a state where the degaussing coil device is mounted on the cathode ray tube, and FIG. 5B is a cross section showing a state where the degaussing coil device is mounted on the cathode ray tube. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Demagnetizing coil 11 ... Loop-shaped coil 12a ... 1st loop part 12b ... 2nd loop part 12c ... 3rd loop part 13a ... 1st twisted part 13b ... 2nd twisted part 15 ... CRT 16 ... Panel Part 17: Funnel part 18: Neck part 19: Shadow mask 20: Inner shield

Claims (8)

[Claims] 1. A single conductive wire is wound a plurality of times to form three substantially rectangular loop coils. The three loop coils are arranged in a cathode ray tube, and degaussing is supplied to the three loop coils. A degaussing coil device characterized in that a degaussing magnetic field is generated by an electric current. 2. The three loop-shaped coils are each formed by winding a single conductive wire in a loop a plurality of times and twisted by about 180 degrees at two twisted portions, and both ends of the twisted portions. 2. The degaussing coil device according to claim 1, comprising: a first loop portion and a second loop portion formed at the first portion, and a third loop portion formed between the torsion portions. 3. A first loop portion and a second loop portion of the three loop-shaped coils are connected to an end portion of a panel portion on which a shadow mask of a CRT is disposed, from a funnel portion on which an inner shield is disposed. The degaussing coil device according to claim 1, wherein the third loop portion is disposed in a funnel portion where an end of the inner shield is disposed. 4. The three loop-shaped coils are individually formed by winding a single conductive wire in a loop a plurality of times.
The first, second, and third loop coils are connected in series so that a demagnetizing current in the same direction is supplied to a portion close to each other in the first to third loop coils. The degaussing coil device as described in the above. 5. The first loop coil and the second loop coil of the three loop-shaped coils are connected from the end of the panel portion where the shadow mask of the cathode ray tube is disposed to the funnel portion where the inner shield is disposed. 5. The degaussing coil device according to claim 1, wherein the third loop coil is disposed in a funnel portion where an end of the inner shield is disposed. 6. A degaussing coil comprising three substantially rectangular loop-shaped coils formed by winding a single conductive wire a plurality of times, and a cathode ray tube having at least a shadow mask and an inner shield built therein, wherein the degaussing coil is provided. The two loop-shaped coils are fixed to face each other from the end of the panel portion where the shadow mask of the cathode ray tube is disposed to the funnel portion where the inner shield is disposed.
A CRT device having a degaussing coil, wherein two loop-shaped coils are attached and fixed to a funnel portion where an end of an inner shield is arranged. 7. The degaussing coil is formed by winding a single conductive wire in a loop a plurality of times and twisting one loop coil by about 180 degrees at two twisted portions, and formed at both ends of the twisted portion. A first loop portion, a second loop portion, and a third loop portion formed between the torsion portions, wherein the first and second loop portions are provided with a shadow mask of a cathode ray tube. From the end of the panel portion to the funnel portion where the inner shield is disposed, and is attached and fixed, and the third loop portion of the degaussing coil is attached and fixed to the funnel portion where the end portion of the inner shield is disposed. A CRT device having the degaussing coil according to claim 6. 8. The degaussing coil comprises first, second, and third loop coils formed by winding a single conductive wire in a loop a plurality of times and individually forming the first and second loops. The coil is attached and fixed opposite to the end of the panel portion where the shadow mask of the cathode ray tube is disposed, from the end portion of the panel portion where the inner shield is disposed, and the third loop coil of the degaussing coil is connected to the end portion of the inner shield. 7. The device according to claim 6, wherein the first to third loop coils are connected in series so that demagnetizing currents in the same direction are supplied to portions adjacent to each other, the first and third loop coils being attached to and fixed to the arranged funnel portion. A cathode ray tube device having the degaussing coil described in the above.