JPH07142008A - Image display device - Google Patents

Abstract

PURPOSE:To effectively restrain unnecessary radiation electric field emitted from the display surface of an image display device in which a cathode-ray tube is used. CONSTITUTION:A cancel electrode 8 formed outside of the funnel 2 of a cathode- ray tube device 1 is arranged between an armor graphite 5 to be earthed and the aperture of a deflection yoke 6 and a pulse voltage of polarity reversed to that of a pulse voltage applied to the deflection yoke is applied to the cancel electrode 8 from a high pressure deflection circuit 20. Thereby, unnecessary radiation electric field can be restrained by inducing, alternating electric field caused by the pulse voltage applied to the deflection yoke and alternating electric field caused by the reversed pulse voltage applied to the cancel electrode, inside the cathode-ray tube and canceling each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device using a cathode ray tube, and more particularly to an image display device having a mechanism for suppressing a high frequency alternating electric field emitted from the display device by using a deflection yoke as a generation source. is there.

[0002]

2. Description of the Related Art Image display devices using cathode ray tubes have been used more and more with the spread of personal computers. The image display device deflects an electron beam by horizontal and vertical deflection magnetic fields generated by a deflection yoke and displays a raster on a phosphor screen. In many cases, a high voltage pulse voltage is applied to the horizontal deflection coil of the deflection yoke,
A sawtooth horizontal deflection current is generated. Therefore, a high-frequency alternating electric field (hereinafter, also referred to as an unnecessary radiation electric field) due to the pulse voltage is emitted from the deflection yoke to the surroundings, which adversely affects electronic devices and the like arranged around the image display device. There has been concern about the influence on the body of the operator of the image display device.

By the way, an alternating magnetic field is radiated from the image display device in addition to the above-mentioned alternating electric field, and unnecessary radiation electric field and a standard for suppressing the unnecessary radiation magnetic field (for example, MPR-2, 1990 in Sweden; TCO guideline 1991). ) Has been established, MPR-2 is 2.5 V / m (50 cm from the tube surface of the cathode ray tube), TCO for the unnecessary radiated electric field in the frequency band of 2 kHz to 400 kHz.
Is 1.0 V / m (30 cm) or less. The above-mentioned unnecessary radiation electric field can be easily suppressed by an electrostatic shield made of a metal plate or the like except the front surface of the cathode ray tube. However, the front part of the cathode ray tube uses transparent glass for displaying an image, and a conductive transparent electrode is formed on the surface of the glass, and the transparent electrode is grounded to shield an alternating electric field. To reduce the electric field.

As a second technique for suppressing the unnecessary radiation electric field, as described in Japanese Patent Laid-Open No. 5-94873, the funnel and neck of the cathode ray tube are coated with a conductive film such as graphite. As a result, there is an image display apparatus that suppresses an unnecessary radiation electric field by shielding an alternating electric field emitted from the deflection yoke. Furthermore, as a third technology, SID 1992 DIGEST pp.13
7 to 140, there is proposed a method of canceling an alternating electric field generated by a pulse voltage applied to a deflection yoke of a cathode ray tube by an alternating electric field generated by a pulse voltage having a polarity opposite to the pulse voltage. Kaihei 4-3
There is one disclosed in Japanese Patent No. 15741 which applies a pulse voltage having a polarity opposite to that of the pulse voltage applied to the deflection yoke of the cathode ray tube to an electrode arranged near the peripheral portion of the entire surface of the cathode ray tube to suppress an unnecessary radiation electric field. It was

[0005]

However, among the above-mentioned conventional techniques, in order to enhance the shielding effect of the conductive transparent electrode, it is necessary to form a transparent electrode having a low resistivity, which increases the manufacturing cost of the cathode ray tube. There was a problem to do.
The second technique has a problem in that so-called ringing occurs in which the deflection current vibrates due to electrostatic coupling between the deflection yoke and the conductive film. The third technique is to cancel an alternating electric field radiated from the inside of the cathode ray tube device by an electric field generated from an electrode provided around the front surface of the cathode ray tube. Therefore, there is a problem that the effect of suppressing the unwanted radiation electric field is small because the physical position of the source of the alternating electric field and the physical position of the cancel electrode are different. An object of the present invention is to provide an image display device which effectively suppresses an unnecessary radiation electric field emitted from the front surface of the image display device using a cathode ray tube.

[0006]

In order to achieve the above object, the present invention arranges a conductor (hereinafter referred to as a cancel electrode) in a portion of a funnel portion of a cathode ray tube where an outer conductive film is not formed. . A pulse voltage having a polarity opposite to that of the pulse voltage applied to the horizontal deflection coil is applied to the cancel electrode, and the reverse pulse voltage is induced in the conductive film inside the cathode ray tube by electrostatic coupling through the glass material of the funnel.

[0007]

According to the above construction, the alternating electric field generated due to the pulse voltage applied to the horizontal deflection coil of the deflection yoke cancels each other out by the alternating electric field generated by the reverse pulse voltage applied to the cancel electrode, so that the cathode ray tube Effectively suppresses the intensity of the unnecessary radiation electric field emitted to the front surface.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a main part of an image display device according to a first embodiment of the present invention, FIG. 2 is a rear view of a cathode ray tube, and FIG. 3 is a schematic view for explaining the operation of the cathode ray tube device. ,
FIG. 4 is a diagram illustrating a circuit configuration for generating a reverse pulse voltage,
FIG. 5 is a diagram showing a change of the reverse pulse voltage waveform with respect to the time axis, and the same components are denoted by the same reference numerals in the respective drawings.

1 and 2, a cathode ray tube 1 has a face plate 3 coated with a phosphor (not shown) on its inner surface, a funnel 2 having an anode button 9 for applying a high voltage embedded therein, and an electron gun (not shown). ) Is sealed, and in the case of a color cathode ray tube, the face plate 3 and the funnel 2 are connected using frit glass (not shown). An exterior graphite 5 coated with graphite, which is a conductor, is provided on a part of the outer surface of the funnel 2 in order to add capacitance to the cathode ray tube.
Ground to operate. Further, a deflection yoke 6 for deflecting the electron beam in the horizontal and vertical directions to obtain a raster is provided outside the neck tube 7.

An explosion-proof band 4 is attached to the side surface of the face plate 3 to enhance the safety when the vacuum container of the cathode-ray tube is imploded, and the cathode-ray tube is installed at the four corners of the explosion-proof band (see FIG. There is a metal fitting for attaching and fixing to (not shown). In the funnel portion between the grounded exterior graphite 5 and the deflection yoke 6, a cancel electrode 8 which is a main part of the present invention is arranged. The cancel electrode 8 is, for example, a conductive coating film formed on the glass surface of the funnel 2, and the terminal T of the high voltage-deflection circuit 20.
The reverse pulse voltage e2 shown in FIG. 5 from 3 is applied.

The high voltage-deflection circuit 20 shown in FIG. 4 comprises a flyback transformer (FBT) 21 and a horizontal deflection circuit (not shown). The FBT 21 includes a primary coil 23 connected to T1 which is a horizontal deflection output terminal and T2 connected to a + B power source, and a secondary coil 22 and an induction coil which are connected in series to a diode and obtain a high DC voltage at a terminal T4. 24
It is equipped with. High voltage (H.
V.) is for accelerating the electron beam emitted from the electron gun to cause the phosphor to emit light. The terminal T4 and the anode button 9
Are electrically connected to each other to apply a DC voltage of about a dozen kV to about 30 kV to the cathode ray tube. The horizontal deflection coil of the deflection yoke 6 is connected to the terminals T1 and T2, and a pulse voltage e1 of several hundreds to 1000V which is repeated in the horizontal cycle shown in FIG. 5 is applied to T1. The pulse voltage e1
As a result, a sawtooth-shaped horizontal deflection current is generated in the horizontal deflection coil in a horizontal cycle to deflect the electron beam to the left and right. One end of the induction coil 24 provided in the FBT 21 is grounded, and at the other end, a pulse voltage e2 having the same phase as the pulse voltage e1 at the terminal T2 but the opposite polarity is generated at the terminal T3.

When the cathode ray tube device 1 is operating, the alternating electric field indicated by the solid arrow 100 and the broken arrow 102 in FIG. 1 is radiated forward through the glass surface of the face plate 3. The alternating electric field 100 is caused by the pulse voltage e1 applied to the deflection yoke 6 and has a waveform as shown by 101, while the alternating electric field 102 is caused by the pulse voltage e2 applied to the cancel electrode 8. 10
The electric field has a waveform as shown in FIG. Next, the mechanism by which the alternating electric field is radiated from the face plate 3 and the operating principle for suppressing the unnecessary radiated electric field will be described in detail with reference to FIG.

In FIG. 3, an inner conductive film 13 coated with conductive graphite, for example, is formed on the inner surface of the funnel 2, and a high voltage (HV) from the terminal T4 passes through the anode button 9. Is being applied. On the other hand, a phosphor that emits light by electron beam irradiation is applied to the inner surface of the face plate 3 to form a phosphor film 11, and aluminum (not shown) is used so that the phosphor film 11 and the inner conductive film 13 have the same potential. The metal back film 12 (only a part of which is shown in the drawing) is vapor-deposited to electrically connect. Although not shown in the figure, in the case of a color cathode ray tube, a color selection electrode such as a shadow mask for selecting color phosphors in the vicinity of the phosphor film should have the same potential as the internal conductive film 13. Be equipped.

In order to reduce the ripple voltage component of the high voltage applied from the terminal T4, the exterior graphite 5 of the funnel 2 is grounded, and several thousand picofarads are provided between the exterior graphite 5 and the interior conductive film 13 via the funnel glass. Capacitance C
5 is formed to improve the ripple characteristics of the DC high voltage applied to the cathode ray tube 1. On the other hand, due to electrostatic coupling between the horizontal deflection coil of the deflection yoke 6 and the internal conductive film 13 (in FIG. 3, the distributed capacitance is represented as an equivalent electrostatic capacitance C6), the terminal T
Pulse voltage e1 similar to pulse voltage e1 applied from 2
Yields 11. Due to the induction of the pulse voltage e11 in the internal conductive film 13, an alternating electric field 100 having a waveform 101 shown in FIG. 1 is emitted to the front surface of the cathode ray tube.

According to the same principle, electrostatic coupling between the cancel electrode 8 formed in a state of non-conduction with the exterior graphite 5 and the interior conductive film 13 (in FIG. 3, the distributed capacitance is equivalent to the equivalent capacitance C
8) causes a pulse voltage e22 similar to the reverse pulse voltage e2 applied from the terminal T3. Due to the induction of the pulse voltage e22 in the internal conductive film 13, an alternating electric field 102 having a waveform 103 shown in FIG. 1 is emitted to the front surface of the cathode ray tube. The two types of alternating electric field 1
00 and 102 have opposite polarities and have similar shapes and the same electric field change state with respect to the time axis, so that they can cancel each other.

Therefore, the face plate 3 of the cathode ray tube 1
The two types of alternating electric fields emitted from the front to each other cancel each other out, and the intensity of the unwanted radiation electric field can be suppressed. as a result,
The composite alternating electric field measured outside the tube is, for example, the arrow 1 in FIG.
As indicated by 04 and waveform 105, the alternating electric field is reduced in intensity, and the influence on the human body can be improved to a level that does not pose a problem.

As described above, the reverse pulse voltage e2 that generates the alternating electric field 102 that cancels the alternating electric field 100 is
The magnitude and phase of the reverse pulse voltage generated in the induction coil 24 of the FBT 21 shown in FIG. 4 and the amplitude adjuster 26 are adjusted by the phase adjuster 25 and the amplitude adjuster 26 to adjust the alternating electric field 100. It is desirable to have a voltage waveform that effectively cancels. The phase adjuster 25 is, for example,
The reverse pulse voltage e2 synchronized with the pulse voltage e1 may be obtained by using a delay line, a combination of passive elements such as resistors and capacitors, or a circuit. The amplitude adjuster 26 is simple, for example, by impedance division, and resistance division or capacitor division is preferable. On the other hand, the waveform of the reverse pulse voltage e2 may vibrate due to the stray capacitance value of the cancel electrode 8 or the inductance value of the induction coil 24, and so-called ringing may occur. In such a case, the ringing suppressor 2
7 is for suppressing the oscillation of the reverse pulse voltage waveform,
A resistance (for example, several hundreds Ω to several kΩ) is connected in series to the induction coil 24, or a resistance and a capacitor are connected in parallel to the induction coil 24 to reduce the oscillation of the voltage waveform and effectively generate the alternating electric field 100. Can be suppressed to.

FIG. 6 shows the reverse pulse voltage value Vp applied to the cancel electrode 8 and the measured values of the intensity of the unwanted radiation electric field. An alternating electric field in the frequency band of 2 kHz to 400 kHz is applied 30 cm from the face plate 3 of the cathode ray tube 1.
The amplitude of the reverse pulse voltage Vp is adjusted to the optimum voltage value Vp (opt), so that the unnecessary radiation electric field strength is changed from 4.3 V / m to 0.8 V / m.
It was confirmed by an experiment that it can be improved to m. This value can satisfy the TCO guideline value (1 V / m) regarding the unnecessary radiated electric field in Sweden, and the influence of the unnecessary radiated electric field on the human body can be significantly reduced.

The reverse pulse voltage e2 can be obtained not only from the flyback transformer but also from the horizontal deflection circuit. Further, as shown in FIG. 7, the deflection yoke 6 is provided with the auxiliary coil 62, and the auxiliary deflection coil 61 is arranged so that the horizontal deflection magnetic field generated by the horizontal deflection coil 61 is linked to the pulse voltage e1 applied to the terminal T2. It is possible to generate a reverse pulse voltage synchronized with
Experiments have confirmed that 0 can be effectively canceled.

8 to 12 show another embodiment of the cancel electrode for applying a reverse pulse voltage according to the present invention.
Each drawing is a view showing the cathode ray tube device 1 from the neck side,
The same parts as those in the first embodiment shown in FIG. 1 are designated by the same reference numerals. In FIG. 8, the cancel electrode 80 is formed by spirally winding a coated electric wire and mounting it between the exterior graphite 5 provided on the funnel 2 and the deflection yoke 6. By applying a reverse pulse voltage to one end T3 of the electric wire, deflection is performed. It has been confirmed by experiments that the alternating electric field generated from the yoke 6 can be effectively suppressed. In FIG. 9, a cancel electrode 81 is a saw-tooth-shaped coated wire that is mounted between the exterior graphite 5 provided on the funnel 2 and the deflection yoke 6, and by applying a reverse pulse voltage to one end T3 of the wire, the deflection yoke is formed. It has been confirmed by experiments that the alternating electric field generated from No. 6 can be effectively suppressed.

In FIG. 10, a cancel electrode 82 is a coated electric wire repeated in a U-shape and mounted between the exterior graphite 5 provided on the funnel 2 and the deflection yoke 6. In this embodiment, the cancel electrode is not arranged in the portion of the funnel 2 where the anode button 9 is present, so that the edge distance between the anode portion and the cancel electrode can be increased and the withstand voltage performance can be improved. . Since the area of the cancel electrode 82 was reduced, it was feared that the effect of canceling the alternating electric field would be reduced as compared with the first embodiment, but the result of the experiment was about 10%, and practically no problem was encountered. I have confirmed that I can do it.

By the way, the embodiment shown in FIG. 9 and FIG.
Alternatively, the cancel electrode 82 is composed of a plurality of cancel electrodes, and after the deflection yoke 6 is attached to the cathode ray tube 1.
By adopting a structure in which the cancel electrode can be attached, the cancel electrode can be easily attached, and the cancel electrode can be relatively easily added to the image display device in which no countermeasure for suppressing the unnecessary radiation electric field is taken. Therefore, the unnecessary radiation electric field of the image display device which is already used can be easily reduced.

FIG. 11 shows the cancel electrode 83 as the exterior graphite 5.
It is arranged in the funnel portion between the and explosion-proof band 4. As the canceling electrode 83, a covered electric wire, a conductive coating material, a metal foil tape or the like is used as in the case of the above embodiment, and an alternating electric field generated from the deflection yoke 6 is applied by applying a reverse pulse voltage to the terminal T3. It has been confirmed by experiments that it can be effectively suppressed.

FIG. 12 shows a case where a part of the exterior graphite 5 is removed and a cancel electrode 84 is formed on the funnel glass material with a conductive coating material, a metal foil, etc. The deflection is performed by applying a reverse pulse voltage to the terminal T3. It has been confirmed by experiments that the alternating electric field generated from the yoke 6 can be effectively suppressed. In the above embodiment, the cancel electrode can be insulated by an insulating tape, an insulating coating material, or the like to prevent electric shock. Further, it has been confirmed by experiments that the above-mentioned insulation has no influence on the effect of suppressing the unnecessary radiation electric field.

13 and 14 show another embodiment of the cancel electrode. The cancel electrode used in this embodiment is, for example, a funnel 2 formed by molding a resin material.
The molded product 86 that substantially matches the outer shape of the above is used. The deflection yoke 6 is attached to a part of the cancel electrode 86, and after the adjustment work, a notch 91 is provided in the attachment portion of the wedge to be inserted into the opening for fixing the deflection yoke 6.
Is provided. A conductive coating material 92 is applied to the inner surface of the resin molded product 86, and a pin 90 electrically connected to the coating material is attached to the cancel electrode 86. The pin 90 is electrically connected to the terminal T3 by the connector 93, and the reverse pulse voltage e
2 is applied to the conductive coating 92 and the deflection yoke 6
It has been confirmed by experiments that the alternating electric field caused by the can be effectively suppressed. In this embodiment, since the cancel electrode is coated on the inside of the resin molded product, there are no measures for preventing electric shock and no problem of withstand voltage with the anode.
It is highly practical.

15 and 16 show another embodiment of the cancel electrode section. These examples are for improving the insulation performance of the cancel electrode portion. Figure 15
Uses a glass container in which a convex portion 30 of glass is provided on a part of the funnel 2. Due to the glass convex portion, the edge distance between the anode button 9 portion and the cancel electrode 87 can be lengthened, and the insulation performance can be improved. In FIG. 16, the resin holder 32 integrally formed with the collar 31 is used to increase the edge distance between the cancel electrode 88 and the anode button 9 to improve the insulation performance.

FIG. 17 shows another embodiment of the cancel electrode section. In this embodiment, for example, a cancel electrode 89 in which a metal foil is wrapped with an insulating film is provided with a portion 89a overlapping the exterior graphite 5 provided on the funnel 2. The amplitude of the reverse pulse voltage is adjusted by the size of the overlapping area 89a.
Experiments have confirmed that the amplitude of the reverse pulse voltage can be easily set to an optimum value.

In the above embodiment, the reverse pulse voltage value required to suppress the unwanted radiation electric field differs depending on the capacitance value between the cancel electrode and the inner conductive film 13 of the cathode ray tube 1, and It was found that when the value is 50 (pF) or more, it can be suppressed by the reverse pulse voltage having a value smaller than the pulse voltage applied to the deflection yoke 6. Further, if the capacitance value is 100 (pF) or more, the absolute value of the reverse pulse voltage for suppressing the unnecessary radiation electric field can be 200 (V) or less, and a special treatment for improving withstand voltage performance is performed. It has been confirmed that it can be used without it.

[0029]

As described above, according to the present invention,
An unnecessary radiated electric field emitted from the face plate of the cathode ray tube to the outside due to the pulse voltage applied to the deflection yoke is applied to the cancel electrode provided in the funnel portion of the cathode ray tube without the outer graphite film, and the reverse pulse voltage is applied. By canceling each other by the alternating electric field induced in the tube,
There is an effect that it can be suppressed to a sufficiently low value. In addition, since it suppresses and suppresses the unwanted radiation electric field in the cathode ray tube, it is not necessary to use a low resistance product with a large shielding effect for the unwanted radiation electric field as a transparent conductive film formed on the surface of the face plate of the cathode ray tube. You can use the product,
There is also an effect that an inexpensive image display device can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an image display device using a cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a diagram showing FIG. 1 from the neck side of a cathode ray tube.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a high voltage-deflection circuit in FIG.

FIG. 5 is a diagram showing a pulse voltage waveform applied to a horizontal deflection coil of a deflection yoke and a reverse pulse voltage waveform applied to a cancel electrode.

FIG. 6 is a diagram showing an effect of suppressing an unnecessary radiation electric field of the present embodiment.

FIG. 7 is a diagram showing another configuration for generating a reverse pulse voltage.

FIG. 8 is a diagram showing a configuration according to another embodiment of the present invention.

FIG. 9 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 10 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 11 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 12 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 13 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 14 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 15 is a diagram showing a configuration according to still another embodiment of the present invention.

FIG. 16 is a diagram showing a configuration according to still another exemplary embodiment of the present invention.

FIG. 17 is a diagram showing a configuration according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cathode ray tube device 2 Funnel 3 Face plate 4 Explosion-proof band 5 Exterior graphite 6 Deflection yoke 61 Horizontal deflection coil 62 Auxiliary coil 7 Neck 8 to 89 Cancel electrode 9 Anode button 10 Transparent conductive film 11 Fluorescent film 12 Metal back film 13 Interior conductive film 20 high voltage-deflection circuit 21 flyback transformer 22, 23, 24 winding 25 phase adjuster 26 amplitude adjuster 27 ringing suppressor 30 convex part of funnel glass 31 holder flange 32 holder 90 connection pin 91 notch 92 conductive film 93 connector

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[Procedure amendment]

[Submission date] November 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 11

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 12

[Correction method] Change

[Correction content]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyuki Kawakami 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Video Media Research Laboratory, Hitachi, Ltd. (72) Inventor Hiroshi Yoshioka 3300 Hayano, Mobara, Chiba Hitachi, Ltd. Factory Electronic Devices Division

Claims (12)

[Claims] 1. An image display device having at least a cathode ray tube and a deflection yoke, wherein a conductor is provided in close contact with or in the vicinity of a portion of the funnel of the cathode ray tube, and the conductor is applied to the deflection yoke. And a means for applying a pulse voltage having a polarity opposite to that of the generated pulse voltage. 2. An image display device having at least a cathode ray tube and a deflection yoke, wherein a conductor is provided in close contact with or in the vicinity of a part of the funnel of the cathode ray tube, and the conductor is applied to the deflection yoke. And a pulse voltage having a polarity opposite to that of the pulse voltage of the cathode ray tube, wherein the pulse voltage of the opposite polarity is induced by electrostatic coupling in a conductive film formed inside the funnel of the cathode ray tube. 3. An image display device having at least a cathode ray tube and a deflection yoke, wherein a conductor is provided in close contact with or in the vicinity of a portion of the funnel of the cathode ray tube, and the conductor is applied to the deflection yoke. Means for applying a pulse voltage having a polarity opposite to that of the pulse voltage applied to the cathode, and the conductor applying the pulse voltage having a polarity opposite to that of the exterior conductive film and the opening of the deflection yoke which are grounded for adding capacitance to the cathode ray tube. An image display device, characterized in that the image display device is disposed in a region between the outer conductive film and the explosion-proof band of the cathode ray tube. 4. The image display device according to claim 1, wherein the conductor to which the reverse polarity pulse voltage is applied is at least a covered electric wire, a metal plate, a metal foil, or a film-shaped resin insulator. One with a conductor pattern formed on it, a conductive coating film,
Alternatively, an image display device characterized by being composed of a material obtained by combining these. 5. The image display device according to claim 1, wherein the conductor to which the reverse polarity pulse voltage is applied is an ungrounded explosion-proof band. 6. The image display device according to claim 1, wherein the means for adjusting at least the amplitude of the reverse pulse voltage, the means for adjusting the phase of the reverse pulse voltage, or the reverse pulse. An image display device comprising means for suppressing vibration of a voltage waveform. 7. The image display device according to claim 1, wherein the reverse pulse voltage is a flyback transformer having an induction coil, a horizontal deflection circuit, or a horizontal deflection magnetic field of the deflection yoke. An image display device characterized by being applied from an induction coil for detection. 8. The image display device according to claim 1, wherein at least a part of a funnel glass of the cathode ray tube is provided with an electrode portion for applying the reverse pulse voltage to improve insulation properties. An image display device, characterized in that it is provided with a convex portion. 9. The image display device according to claim 1, further comprising: a holder provided with an insulating collar-shaped resin member in the electrode portion to which the reverse pulse voltage is applied. Characteristic image display device. 10. The image display device according to claim 1, wherein a deflection yoke is attached to the cathode ray tube, and then a conductor for applying the reverse pulse voltage is attached to the cathode ray tube. An image display device characterized by the above. 11. The image display device according to claim 1, wherein an area in which a part of the conductor to which the reverse pulse voltage is applied overlaps an exterior conductive film formed outside a funnel is variable. An image display device characterized by the above. 12. The image display device according to claim 1, wherein a capacitance C generated between the conductor applying the reverse polarity pulse voltage and the internal conductive film of the cathode ray tube. But 50 (pF)
An image display device having a range of ≦ C <2000) (pF).