KR920010657B1 - Cathod ray tube lessening leakage magnetic field - Google Patents

Abstract

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Description

Cathode ray tube device to reduce magnetic field leaking to the outside

1 is a leakage magnetic field distribution diagram showing a distribution of a horizontal deflection leakage magnetic field generated in a horizontal deflection coil of a deflection yoke together with a cathode ray tube.

Figure 2a is a diagram showing the distribution of the horizontal deflection leakage magnetic field on the vertical plane 65cm away from the center of the VDU.

FIG. 2B is a diagram showing the distribution of magnetic flux generated when a coil is generated at the center of the VDU to generate a magnetic field opposite to the main deflection magnetic field of the leakage magnetic field generated by the horizontal deflection coil; FIG.

3A and 3B are rear perspective and side views showing a conventional cathode ray tube apparatus in which a pair of compensation coils are disposed on a plane perpendicular to the tube axis passing through the center of the leakage magnetic field on both sides of the horizontal plane including the tube axis;

4A is a graph showing a time variation of a compensation magnetic field generated in a pair of compensation coils synchronized with a horizontal deflection signal.

Figure 4b is a graph showing the time change of the leakage magnetic field leaked from the VDU.

Figures 5a and 5b is a rear perspective view and part broken side view showing a color cathode ray tube device according to one embodiment of the present invention.

6 is a diagram showing the distribution of a compensating magnetic field on a vertical plane 5 cm away from the center of the VDU in the color cathode ray tube apparatus shown in FIGS. 5A and 5B.

7A and 7B are magnetic field distribution diagrams for explaining the effect of the compensation magnetic field on the landing characteristics in the cathode ray tube apparatus in which the two pairs of compensation coils shown in FIGS. 5A and 5B are arranged. It is a magnetic field distribution diagram for explaining the effect of a compensating magnetic field on a landing characteristic in the conventional cathode ray tube apparatus which arrange | positioned a coil.

* Explanation of symbols for the main parts of the drawings

24: skirt portion 25: panel

26: funnel 27: outer container

28: phosphor screen 29: shadow mask

30: mask body 31: mask frame

34: Konbu 35: Neck

36: electron gun barrel 42: signal generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube device, and more particularly to a cathode ray tube device that reduces a leakage magnetic field leaking out of a cathode ray tube device from a horizontal deflection coil of a deflection yoke.

With the spread of visual display units (VDUs), there is an active discussion about the effects of leakage magnetic fields on the human body.

At present, no conclusions have been drawn on its credibility and causality, but there is a movement to call attention to North Europe.

For example, in Sweden, the National Council for Metrology and Testing included a 15 cm cathode ray tube along the center of the VDU (the tube axis from the surface of the faceplate) in the guidelines for testing and evaluation of the VDU (MPR-P 1988). The magnetic flux density B = 50nT and the induced magnetic flux density on the spherical surface of a radius 65 cm (50 cm from the face of the faceplate on the tube axis) from the inner side of the VDU is defined as the center of the VDU. The recommended value is dB / dt≤25mT / s.

The main source of the leakage magnetic field of the VDU is the horizontal deflection coil of the deflection yoke mounted on the cathode ray tube.

Generally, the deflection yoke is composed of a magnetic core, a horizontal deflection coil and a vertical deflection coil, and a magnetic field is generated as shown by a broken line from the horizontal deflection coil 1 wound in a saddle shape, for example, as shown in FIG.

The leakage magnetic field of the horizontal deflection coil 1 is roughly divided into an effective magnetic flux Ba and an ineffective magnetic flux Bb generated from the wiring portion 2 of the horizontal deflection coil 1. do.

These deflection magnetic fields Ba (Bb) are generated in opposite directions to each other.

These deflection magnetic fields Ba (Bb) form a particularly complex leak magnetic field in the vicinity of the deflection yoke 3, as shown by arrows 4 in FIG. 2a on a vertical plane perpendicular to the tube axis about 45 cm from the center of the VDU. It forms a simple leak magnetic field.

This simple leakage magnetic field is close to the distribution of the magnetic field generated when the coil 6 generating the magnetic field Bc in the opposite direction to the main deflection magnetic field Ba is located at the center of the VDU, as indicated by the arrow 5 in FIG. .

In order to eliminate such a horizontal deflection leakage magnetic field, the cathode ray tube device 9 shown in Japanese Patent Application Laid-Open No. 62-100935 shows the center of the leakage magnetic field on both sides of the horizontal plane including the tube axis ZZ as shown in FIGS. 3A and 3B. A pair of compensation coil units 8a and 8b is provided on a plane 7 perpendicular to the tube axis passing through O), and a horizontal deflection current is caused to flow through the pair of compensation coil units 8a and 8b. The leakage magnetic field is reduced by generating a magnetic field which eliminates the leakage magnetic field Bb passing through the pair of compensation coil units 8a and 8b, that is, the magnetic field in the same direction as the main deflection magnetic field Ba.

However, in the conventional cathode ray tube apparatus 9, FIG. 4A is influenced by the influence of an inner magnetic shield, a shadow mask, and a conductive coating film provided near the pair of compensation coil units 8a, 8b. And a phase difference (Δψ), that is, a time shift, between the waveform 10 of the magnetic field generated in the pair of compensation coil units and the waveform 11 of the leaked magnetic field, as shown in FIG. 4B, respectively, to sufficiently compensate the leakage magnetic field. There is a problem that you can not.

In addition, since the horizontal deflection current flows through the pair of compensation coil units, the impedance of the deflection circuit is increased, thereby increasing the loss of deflection power.

In addition, since the pair of compensation coil units are disposed on the inclined outer surface of the funnel-shaped cone part center, there is a problem in that the attachment is unstable and the position adjustment is not easy.

In the conventional cathode ray tube apparatus provided with a compensation coil unit for eliminating the horizontally deflected leakage magnetic field, an internal magnetic seal installed in the cathode ray tube is provided because a pair of compensation coil units are installed near the center of the leakage magnetic field on both sides of the horizontal plane including the tube axis. Due to the influence of the shadow mask and the conductive coating film, there is a problem that a phase difference occurs between the waveforms of the magnetic field and the leakage magnetic field generated by the pair of compensation coil units, so that the leakage magnetic field cannot be sufficiently reduced. The flow of horizontal deflection current through the unit increases the impedance of the deflection circuit, increasing the loss of deflection power.

In addition, there is a problem that the position adjustment is not easy because the attachment of the pair of compensation coil unit is unstable.

An object of the present invention is to sufficiently compensate for the magnetic field leaking from the VDU on the spherical radius of 65 cm from the center of the VDU, in particular to easily suppress the leakage magnetic field in front of the tube and to reduce the loss of deflection power in the compensation coil unit It is to provide a cathode ray tube device that can be.

According to the present invention, electron beam generating means for generating an electron beam; Light ray generating means for generating light rays when the electron beam is landing; An outer container having an axis, the outer container for accommodating the electron beam generating means and the light generating means; Deflection magnetic field generating means which is provided on the outer side of the outer container and generates a main deflection magnetic field for deflecting the electron beam horizontally in the outer container and generates a leakage magnetic field out of the outer container; It is installed outside the outer container on the side of the light generating means with respect to the first reference plane passing through the center of the horizontally deflected leakage magnetic field, perpendicular to the tube axis, and intersecting the outer container, so that the first compensation system is opposite to the leakage magnetic field outside the outer container. First reward box generating means for generating and reducing the leakage magnetic field; A second reward system generating means installed on the outside of the outer container on the electron beam generating means side with respect to the first reference plane, and generating a second compensation system in a direction opposite to the leakage magnetic field outside the outer container; Provided is a cathode ray tube apparatus having signal generating means for generating a signal in addition to the deflecting magnetic field generating means and the first and second complementary field generating means.

According to the present invention, there is provided an outer container including a face plate, a panel having a skirt portion in contact with the face plate, a funnel connected to the skirt portion of the panel, and a net extending from the funnel, the outer container having a tube axis; An electron muzzle which is disposed in the net and generates an electron beam; A screen formed on the faceplate to generate light rays when the electron beam is landing; Horizontal deflection means provided on an outer surface of the funnel to generate a deflection magnetic field for deflecting the electron beam in a horizontal direction and to generate a leakage magnetic field out of the outer container; First compensation in the direction opposite to the leakage magnetic field outside the outer container, disposed on the face plate side of the first reference surface perpendicular to the tube axis and passing through the center of the leakage magnetic field on both sides of the second reference plane parallel to the horizontal direction, including the tube axis. First and second compensation coil units generating magnetic fields to reduce leakage magnetic fields; Third and fourth compensation coil units disposed on both sides of the second reference plane and disposed on the electron barrel side of the first reference plane to generate a second compensation system in a direction opposite to the leakage magnetic field outside the outer container to reduce the leakage magnetic field; Provided is a cathode ray tube apparatus having deflecting magnetic field generating means and first, second, third and fourth compensation coil units.

5A and 5B show a color cathode ray tube device according to one embodiment of the present invention.

The color cathode ray tube device is composed of a color cathode ray tube 20, a deflection yoke 21 mounted on the outside thereof, and a compensator 22 mounted on the outside thereof to generate a compensation magnetic field.

The color cathode ray tube 20 has an outer container 27 having a panel 25 having a skirt portion 24 at its rim and a funnel-shaped funnel 26 integrally bonded to the panel 25. A phosphor screen 28 composed of a tri-color phosphor layer emitting blue, green, and red rays when an electron beam lands on the inner surface of the panel 25 is formed.

A shadow mask 29 is provided inside the panel 25 in proximity to the phosphor screen 28.

The shadow mask 29 is composed of a mask body 30 having a hole for allowing the electron beam to pass therethrough and facing the phosphor screen 25 and a mask frame 31 supporting the peripheral portion thereof. The mask frame is made of magnetic material such as low carbon steel.

Similarly, a cylindrical inner magnetic shield 33 made of magnetic material is attached to the mask frame 31 of the shadow mask 29 and extends into the cone part 34 of the funnel 26.

In the neck 35 of the funnel 26, an electron muzzle body 36 for emitting three electron beams is provided.

The inner conductive coating film 37 is applied from the inner surface of the cone portion 34 of the funnel 26 to the adjacent portion of the inner surface of the neck 35, and the outer conductive coating film 38 is formed on the outer surface of the cone portion 34. have.

In addition, "39" is an explosion-proof band which tightens the skirt part 24 of the panel 25, and "40" is an anode terminal provided in the cone part 34 of the funnel 26. As shown in FIG.

The deflection yoke 21 mounted outside the boundary between the cone portion 34 and the neck 35 of the funnel 27 is a horizontal deflection coil for deflecting three electron beams emitted from the electron muzzle 36 in a horizontal direction, and a deflection in the vertical direction. It has a vertical deflection coil and a magnetic core.

In particular, the deflection yoke 21 of the cathode ray tube apparatus shown in FIGS. 5A and 5B has a saddle-shaped horizontal deflection coil and a magnetic core.

In the cathode ray tube apparatus shown in FIGS. 5A and 5B, the compensator 22 for generating the compensating magnetic field is a plane perpendicular to the tube axis passing through the center of the horizontal deflection leakage magnetic field generated in the horizontal deflection coil of the deflection yoke 21. It consists of a pair of front compensation coil units 22a and 22b arrange | positioned on both sides of the (first reference plane) 70, and a pair of compensation coil units 22c and 22d behind.

The pair of front compensation coil units 22a and 22b is disposed at a position substantially symmetrical with respect to the second reference plane (horizontal reference plane) including the tube axis ZZ of the color cathode ray tube 20, To face both sides, the cone portion of the funnel 26 on which the inner magnetic shield 33 is disposed or on the outer surface of the skirt portion 24 of the panel 25 on which the shadow mask 29 is disposed. It is fixed on the outer surface of 34, for example with an adhesive.

In particular, in the case where the pair of front compensation coil units 22a and 22b are to be fixed on the skirt portion 24 of the panel 25, the explosion-proof band 39 which tightens the skirt portion 24 can be easily used. I can attach it.

In addition, the rear pair of compensation coil units 22c and 22d are similarly disposed at positions substantially symmetrical with respect to the second reference plane including the tube axis ZZ of the color cathode ray tube 20 so as to be opposed to both of the horizontal reference planes. It is fixed on the magnetic core of the deflection yoke 21.

These compensation coil units "22a", "22b", "22c" and "22d" have approximately the same size and shape, but the number of windings of the compensation coils and the inclination with respect to the horizontal plane are as follows.

That is, the front compensation coil units 22a and 22b mainly compensate for the leakage magnetic field in front of the cathode ray tube, and the rear compensation coil units 22c and 22d mainly compensate for the leakage magnetic field in the rear of the cathode ray tube.

Since the inclination of the front compensation coil units 22a and 22b with respect to the horizontal plane is dependent on the inclination of the funnel, there is a possibility that the compensation in front of the cathode ray tube may be weakened, so that the foundation is prepared and arranged horizontally, and the rear compensation coil units 22c ( 22d) is just fixed on the magnetic core of the deflection yoke 21.

The number of turns of the front and rear compensation coil units 22a, 22b, 22c, and 22d is the number of turns that minimizes the leakage magnetic field.

These compensation coil units 22a, 22b, 22c, and 22d are connected in series or in parallel with the horizontal deflection coils of the deflection yoke 21 to operate as signals of the signal generator 42.

The signal generator 42 includes a horizontal signal generating circuit for generating a horizontal deflection current, and from the signal generator 42, a current proportional to the horizontal deflection current is supplied to the compensation coil units 22a, 22b, 22c, and 22d. do.

The signal generator 42 may be provided separately from the horizontal signal generation circuit without including the horizontal signal generation circuit for generating the horizontal deflection current.

The signal generator 42 is supplied with a current having a level proportional to the horizontal deflection current and having the same time change in synchronism with the horizontal deflection current to the compensation coil units 22a, 22b, 22c, and 22d.

As described above, the provision of two pairs of compensation coils 22a, 22b, 22c, and 22d in the front and rear of the color cathode ray tube achieves a characteristic of compensating for a very good leakage magnetic field as described below.

(1) By adjusting the attachment position of the front and rear two pairs of compensation coil units 22a, 22b, 22c, and 22d or the current flowing through the two pairs of compensation coils, leakage magnetic fields other than the front of the panel 25 can be effectively compensated. .

6 shows the compensation magnetic field on the vertical reference plane 15 cm away from the outer surface of panel 26 of the color cathode ray tube 20 and 65 cm from the center of the inner VDU by the VDU test evaluation method, as indicated by the arrow 44. A compensating magnetic field is formed like a conventional cathode ray tube apparatus in which a pair of compensating coils are arranged on the center of the horizontal deflection leakage magnetic field.

(2) In the conventional cathode ray tube apparatus, as shown in FIGS. 4A and 4B, the leakage magnetic field could not be sufficiently compensated due to the phase difference (Δψ) between the horizontally deflected leakage magnetic field and the compensating magnetic field, but as described above, the two front and rear pairs were compensated. When the coil units 22a, 22b, 22c, and 22d are disposed, the horizontal deflection leakage magnetic field and the phase difference generated from the deflection yoke 21 are small due to the influence of magnetic materials such as the shadow mask 29 and the internal magnetic shield 33, etc. Compensation magnetic field can be generated to effectively compensate for the leakage magnetic field.

(3) By arranging the front and rear two pairs of compensation coil units 22a, 22b, 22c, and 22d shown in Figs. 5A and 5B, a current in proportion to the horizontal deflection current flows through these compensation coil units. 21) can reduce the loss of deflection power.

In other words, the deflection power is generally dependent on the impedance (Z) of the deflection coil unit, and the resistance of the deflection coil unit and the compensation coil unit is R, and the inductance of the compensation coil unit is L.

Becomes

Therefore, to reduce the deflection power, the inductance of the compensation coil unit which does not contribute to the deflection may be lowered.

However, in the case of compensation coil

R 《2πfL

N is the number of turns of the coil, and the strength of the magnetic flux is ψ

L = Nψ / I∝N ²

Therefore, the deflection power increases in proportion to the square of the number of turns N of each coil.

On the other hand, the strength of the compensating flux generated in the pair of compensation coils is proportional to the sum of the number of turns N of the coils forming the pairs.

Therefore, when two pairs of compensation coil units 22a, 22b, 22c, and 22d are used as in the cathode ray tube apparatus shown in FIGS. 5A and 5B, the sum of the number of wounds N is compared with that of the conventional pair of compensation coil units. Even if it is about the same, L decreases and the total inductance decreases with a compensating flux of the same strength as a pair of compensation coil units, and power loss can be reduced in the compensation coil units 22a, 22b, 22c, and 22d, and thus deflection power. Can reduce the loss.

(4) Horizontal deflection In the conventional cathode ray tube apparatus in which a pair of compensating coil units are arranged on the center of the leakage magnetic field, the main deflection generated in the horizontal deflection coil of the deflection yoke 21 in the passage region of the electron beam as shown in FIG. 7B. Since the compensating magnetic flux 46 in the same direction as the magnetic flux 45 is generated, the deflection of the electron beam increases and the landing of the fluorescent surface on the three-color phosphor layer shifts outward.

However, as shown in FIG. 7A, when two pairs of forward and backward compensation coil units 22a, 22b, 22c, and 22d are arranged on both sides of a plane perpendicular to the tube axis passing through the center of the horizontal deflection leakage magnetic field, Compensation coil units 22a and 22b generate a compensating magnetic flux 46a in the same direction as the main deflection magnetic flux 45 generated in the horizontal deflection coil of the deflection yoke 21 in the passage region of the electronic load, but is disposed rearward. The pair of rearward compensation coil units 22c and 22d that generate the reverse compensation magnetic flux 46b can make the sum of the compensation magnetic fields almost zero in the passage area of the electron beam, making it difficult to cause landing variations. Can be.

(5) As shown in Figs. 5A and 5B, when the compensator is formed by two pairs of forward and backward compensation coil units, the degree of freedom of its mounting position is increased, and the compensation coil units 22a, 22b, 22c, and 22d are relatively simple. Can be placed.

Table 1 shows a specific embodiment of a cathode ray tube device in which two pairs of compensation coil units 22a, 22b, 22c, and 22d are arranged, and a conventional cathode ray tube device in which one pair of compensation coil units 8 are arranged.

TABLE 1

Table 2 compares and shows the characteristics of the cathode ray tube apparatus provided with the two pairs of compensation coil units 22a, 22b, 22c, and 22d of Table 1 mentioned above, and the cathode ray tube apparatus provided only with a pair of compensation coils.

In Table 2, the induction magnetic flux density is expressed in dB / dt and the magnetic flux density is represented by B. The value at the distance of 30 cm in front of the panel and the 65 cm spherical or horizontal plane by the VDU are

-45 ° ≤θ≤45 °

The maximum value in the range of was shown.

In addition, the increase in inductance of the horizontal deflection meter represents the increase in% before and after connecting the compensation coil unit in series to the horizontal deflection coil.

TABLE 2

As shown in Table 2, in the conventional pair of compensating coil units, the induced magnetic flux density (dB / dt) at 30 cm in front of the panel is 13 mT / s, and the induced magnetic flux density (dB / dt) at the spherical surface of 65 cm by VDU. 9 mT / s, an inductance increase of 9.3% is the limit, but as shown in the example, two pairs of compensating coils are used to pass a pair of them to the panel adjacent to the plane perpendicular to the tube axis passing through the center of the horizontally deflected magnetic field. If the other pair is placed on the magnetic core (rear) of the deflection yoke (front), the inductive flux density (dB / dt) at 30 cm in front of the panel can be reduced to 6 mT / s and the inductance increase to 7.8%.

As described above, a compensator for generating a compensating magnetic field for reducing a horizontal deflection leakage magnetic field is composed of a pair of compensating coil units, and the pair of compensating coil units is a plane perpendicular to the tube axis passing through the center of the horizontal deflecting magnetic field. By arranging at least one pair on each side of each side, the pair of compensation coil units arranged on one side thereof can effectively compensate for the horizontal deflection leakage magnetic field by reducing the phase difference with the horizontal deflection leakage magnetic field in front of the tube.

In addition, by arranging a pair of compensation coil units on the other side in a balanced manner, a water deflection leakage magnetic field other than the front of the pipe can be compensated in the same manner as a cathode ray tube device in which a pair of compensation coil units are disposed in the related art.

As described above, a cathode ray tube apparatus capable of sufficiently compensating for a leakage magnetic field caused by a VDU and easily taking countermeasures for intensively reducing the leakage magnetic field in front of the tube operating the VDU can be provided.

Claims (11)

Electron beam generating means 36 for generating an electron beam; Light ray generating means 28 for generating light rays when the electron beam is landing; An outer container (27) having an axis (Z-Z) for accommodating the electron beam generating means (36) and the light beam generating means (28); Deflecting magnetic field generating means (21) which is provided outside the outer container (27) to generate a main deflection magnetic field in the outer container for deflecting the electron beam in a horizontal direction, and generates a leakage magnetic field outside the outer container (27); It is installed outside the outer container 27 on the light generating means 28 side with respect to the first reference plane 70 passing through the center of the horizontal deflection leakage magnetic field, perpendicular to the tube axis, and intersecting the outer container 27. 27) first compensation system generating means (22a) and (22b) for generating a first compensation system in a direction opposite to the other leakage magnetic field to reduce the leakage magnetic field; It is installed on the outer side of the outer container 27 on the electron beam generating means 36 side with respect to the first reference plane 70, and generates a second compensation system in a direction opposite to the leakage magnetic field outside the outer container 27 to prevent the leakage magnetic field. Second reward box generating means (22c) (22d) for reducing; Leakage to outside characterized in that it comprises a signal generating means 42 for generating a signal in addition to the deflection magnetic field generating means 21 and the first and second compensation system generating means (22a, 22b, 22c, 22d) Cathode ray tube device which reduced magnetic field becoming. The first and second compensation system generating means (22a) (22b) are disposed on both sides of a second reference plane that includes a tube axis (zz) and is parallel to the horizontal direction, so as to generate a compensation magnetic field. And a second compensation coil unit (22a) (22b), wherein said second compensation system generating means (22c) (22d) includes a pipe axis (zz) and is disposed on both sides of the second reference plane parallel to the horizontal direction to compensate the magnetic field. And a third and fourth compensation coil units (22c) and (22d) for generating a negative electrode tube to reduce the magnetic field leakage to the outside. 3. The method of claim 2, wherein the first, second, third and fourth compensation coil units 22a, 22b, 22c and 22d are electrically connected in series with the deflection magnetic field generating means 21. Cathode ray tube device which reduced magnetic field which leaked. 3. The method of claim 2, wherein the first, second, third and fourth compensation coil units 22a, 22b, 22c and 22d are electrically connected in parallel with the deflection magnetic field generating means 21. Cathode ray tube device which reduced magnetic field which leaked. The first and second compensation system according to claim 1, wherein a compensation current synchronized with a horizontal deflection current is supplied to the first, second, third and fourth compensation coil units 22a, 22b, 22c, and 22d. A cathode ray tube apparatus which reduces the magnetic field leaking to the outside, characterized by operating the generating means (22a, 22b, 22c, 22d). The signal generating means (42) according to claim 1, wherein the signal generating means (42) generates a horizontal deflection current and supplies it to the deflecting magnetic field generating means (21) to operate the deflecting magnetic field generating means (21) and to synchronize with the horizontal deflection current. First and second compensation currents are generated and supplied to the first and second compensation system generating means 22a, 22b, 22c, 22d, and the first and second compensation system generating means 22a, 22b, 22c, 22d. Cathode ray tube device to reduce the magnetic field leakage to the outside, characterized in that for operating. A panel 25 having a face plate, a skirt portion 24 in contact with the face plate, a funnel 26 connected to the skirt 24 of the panel 25, and a net 35 extending from the funnel 26. It includes, and the outer container 27 having a tube axis; An electron muzzle body (36) disposed in the net (35) to generate an electron beam; A screen 28 formed on the faceplate to generate light rays when the electron beam is landing; Horizontal deflection means (21) provided on an outer surface of the funnel (26) for generating a deflection magnetic field for deflecting the electron beam in a horizontal direction and for generating a leakage magnetic field out of the outer container; A leakage magnetic field outside the outer container 27 is disposed on the face plate side of the first reference surface 70 perpendicular to the tube axis and passing through the center of the leakage magnetic field on both sides of the vertical reference plane parallel to the horizontal direction, including the tube axis zz. First and second compensation coil units 22a and 22b which generate a first compensation system in a direction opposite to and reduce the leakage magnetic field; Third and third sides arranged on the electron gun sphere 36 side of the first reference plane 70 on both sides of the second reference plane to generate a second compensation system in a direction opposite to the leakage magnetic field outside the outer container 27 to reduce the leakage magnetic field. Fourth compensation coil units 22c and 22d; And a signal generating means 42 for generating a signal for operating the deflection magnetic field generating means 21 and the first, second, third and fourth compensation coil units 22a, 22b, 22c, 22d. The cathode ray tube device which reduced the magnetic field leaking to the outside characterized by the above-mentioned. 8. The cathode ray tube apparatus as claimed in claim 7, wherein the first and second compensation coil units (22a, 22b) are provided on a skirt portion (24). 8. The cathode ray tube device according to claim 7, wherein the third and fourth compensation coil units (22c) (22d) are provided on an outer surface of the funnel (26). 8. The magnetic shield (33) according to claim 7, wherein the first and second compensation coil units (22a, 22b) are disposed in the outer container (27) to prevent leakage of magnetic fields in the outer container (27). Cathode ray tube device to reduce the magnetic field leakage to the outside, characterized in that installed in. 8. The magnetic field leakage to the outside of claim 7, wherein the horizontal deflection means (21) comprises a magnetic core and a coil wound around it, and the third and fourth compensation coil units are disposed on the magnetic core. Reduced cathode ray tube device.

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