JPH0721945A - Cathode-ray tube device - Google Patents

Abstract

PURPOSE:To add a function to damp an alternating electric field of a deflection yoke irradiated to the front after transmitting a funnel and a panel to a cathode ray tube. CONSTITUTION:A conductive film 8 for an electric field shield formed so as to electrically connect to a conductive film from the region having larger diameter than the opening diameter of a horizontal deflection coil of a cone 1b in a glass bulb 10 to the region before a neck seal line 1e in a neck 1a, and an insulating film 9 formed so as to cover the conductive film 8 are installed. During operation, the conductive film 8 is grounded to form an equal potential surface of 0v in the front of a deflection yoke 7. The electric field shield surface is formed in the front of the the deflection yoke 7, and an alternating electric field irradiated to the front from the deflection yoke 7 is damped. The insulation between the deflection yoke 7 and the conductive film 8 can be kept by the insulation film 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube device in which an alternating electric field radiated from a deflection yoke is reduced.

[0002]

2. Description of the Related Art FIG. 2 is a side view of a conventional cathode ray tube.
In the figure, reference numeral 10 denotes a glass bulb, which is constructed by frit-sealing a panel portion 2 on a funnel portion 1, and the funnel portion 1 is constituted by a funnel body portion 1c having a neck portion 1a, a cone portion 1b, and a high-pressure anode button 1d. There is. 1e is a joint between the neck portion 1a and the cone portion 1b, which is a portion called "neck seal line",
It is a part where the glass thickness is a little thin and the strength is weaker than other parts. An electron gun 3 is enclosed in the neck portion 1a, and an explosion-proof band 4 for ensuring explosion-proof characteristics is wound around the side surface of the panel portion 2. Further, a silicon resin film 5 for insulation is formed around the high-voltage anode button 1d provided on the funnel body 1c, and a capacitance is provided to the cathode ray tube on the outer surface of the funnel body 1c. A conductive film 6 for adding is formed. The conductive film 6 is usually formed by applying graphite.

A cathode ray tube having such a structure is shown in FIG.
4, a deflection yoke 7 for deflecting the electron beam is attached at a position between the cone portion 1b and the neck portion 1a, and the deflection yoke 7 is, as shown in FIG.
It is composed of a horizontal deflection coil 7a, a vertical deflection coil 7b, and a deflection yoke main body portion 7c.

Next, the operation of the conventional cathode ray tube will be described. The electron beam emitted from the electron gun 3 is deflected in the horizontal and vertical directions by the horizontal deflection coil 7a and the vertical deflection coil 7b of the deflection yoke 7, and scans the fluorescent film formed on the inner surface of the panel section 2. Display the desired image. The deflection swing width at this time is inversely proportional to the square root of the voltage applied to the anode button 1d.

[0005]

The conventional cathode ray tube device has no borrowing to shield the alternating electric field radially generated around the deflection yoke when deflecting the electron beam, and therefore is harmful to the human body. There is a problem that the alternating electric field is transmitted through the funnel portion and the panel portion of the cathode ray tube and radiated in front of the cathode ray tube.

The present invention has been made to solve the above problems, and an object thereof is to obtain a cathode ray tube device capable of reducing the alternating electric field radiated from the deflection yoke to the front of the cathode ray tube.

[0007]

In the cathode ray tube apparatus according to the present invention, a connecting portion between a neck portion and a cone portion is formed from a region having a diameter larger than an opening diameter of a horizontal deflection coil of a cone portion on which a deflection yoke is mounted. A conductive film for electric field shielding is formed on the outer surface of the glass bulb up to the vicinity thereof to be grounded, and an insulating film is formed on the conductive film.

[0008]

The conductive film for the electric field shield formed in the region from the cone portion where the deflection yoke of the funnel portion according to the present invention is mounted to the portion before reaching the neck portion is formed through the conductive film for forming electrostatic capacitance. Since an equipotential surface of 0 v, that is, an electric field shield surface is formed on the inner peripheral surface of the opening of the deflection yoke which is grounded, it is possible to reduce an alternating electric field radiated forward through the funnel portion and the panel portion. Since the electrically conductive film for electric field shield and the deflection yoke are electrically insulated by the insulating film, the insulation of the deflection yoke is not damaged.

[0009]

【Example】

Example 1. 1 is a partially cutaway side view of a first embodiment of the present invention, in which the same reference numerals as those in FIGS. 2 to 4 denote the same or corresponding portions, and 8 denotes a conductive film for electric field shielding, and a conductive film 6 Cone portion 1b so as to be electrically connected to
To the front of the seal line of the neck portion 1a, graphite is applied so as to cover the front surface of the opening of the deflection yoke 7. An insulating film 9 is formed on the conductive film 8 in order to electrically insulate the conductive film 8 and the deflection yoke 7, and is formed by applying an alumina dispersion paint in this embodiment.

Next, the operation will be described. In the cathode ray tube device configured in this manner, the conductive film 6 and the conductive film 8 that is in conduction with the conductive film 6 are grounded by grounding the conductive film 6.
It becomes an equipotential surface of v, and from the deflection yoke 7 to the funnel portion 1
The alternating electric field that is transmitted through and is radiated to the front of the panel 2 is reduced.

Further, since the insulating film 9 is formed on the conductive film 8, it is electrically insulated from the deflection yoke 7 and no problem such as discharge occurs.

In the first embodiment, the insulating film 9 is made of the alumina dispersed paint, but it may be made of a non-magnetic insulating material such as magnesia dispersed paint.

[0013]

As described above, according to the present invention, the electric field shield is provided on the outer surface of the glass bulb in the region from the cone portion where the deflection yoke of the funnel portion is mounted to the point before the next portion of the neck portion. Since the conductive film for the electric field shield is grounded during the operation, the conductive film for the electric field shield is grounded during the operation. That is, since the electric field shield surface is formed, it is possible to reduce an alternating electric field that is transmitted through the funnel portion and the panel portion and is radiated to the front surface, and the neck seal line portion having a small thickness and weak strength has a large electric resistance. Since it is kept in the state, it is possible to prevent the phenomenon that the electric field is locally concentrated to a small place, and the insulation between the conductive film and the deflection yoke is maintained by the insulating film, so that the cathode ray tube device Effect can be maintained-reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a cathode ray tube device according to a first embodiment of the present invention.

FIG. 2 is a side view of a conventional cathode ray tube.

FIG. 3 is a side view of a conventional cathode ray tube device.

FIG. 4 is a perspective view of a deflection yoke used in the cathode ray tube device.

[Explanation of symbols]

 1 funnel part 1a neck part 1b cone part 1c funnel body part 2 panel part 6 conductive film 7 deflection yoke 7a horizontal deflection coil 7b vertical deflection coil 8 electric field shielding conductive film 9 insulating film 10 glass valve

Claims (1)

[Claims] 1. A funnel portion main body having a conductive film for forming a capacitance formed on an outer surface, a cone portion, a funnel portion including a neck portion, and a panel portion coupled to the funnel portion. A glass bulb, a conductive material for an electric field shield formed on the outer surface of a region having a diameter larger than the opening diameter of the horizontal deflection coil of the cone portion of the glass bulb to the vicinity of the joint portion between the cone portion and the neck portion A cathode ray tube device comprising a film and an insulating film formed on the conductive film, wherein the conductive film for shielding the electric field is grounded via the conductive film for forming the electrostatic capacitance.