JP3054791B2 - Cathode ray tube device - Google Patents

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 used for an image display device.

[0002]

2. Description of the Related Art FIG. 2 is a schematic sectional view showing a conventional cathode ray tube device. In the drawing, reference numeral 1 denotes a known cathode ray tube including a neck portion 2, a funnel portion 5, and a panel portion 8 in this order. A cathode 21, a first grid 20, a second grid 19, a focusing electrode 18, an anode 17
However, an electron gun 3 is provided which is fixed by a bead glass 22 in this order at a required interval from the end of the neck portion 2. A phosphor 9 is applied to the inner surface of the panel portion 8 of the cathode ray tube 1, and a mask 10 is fixed inside the panel portion 9 at a required interval.

A deflection yoke 12 is mounted near the connection between the neck portion 2 and the funnel portion 5 by fixing the deflection yoke holder 13 with a clamp 14. The deflection yoke holder 13 is formed by integrally forming a flange 13b perpendicular to the outer surface at the center of a cylindrical portion 13a, and the front end of the flange 13b is bent into a panel portion 8. The deflection yoke 12 is fitted in a portion on the panel portion 8 side surrounded by the cylindrical portion 13a and the flange portion 13b. Further, the cylindrical part 13a on the electron gun 3 side is fixed to the fastening
A purity magnet 15 for adjusting color purity is provided on the base side of the electron gun 3 side of the flange portion 13b.
Electromagnetic magnet 16 for convergence correction at the end
Is provided.

The end of the neck portion 2 is sealed by a stem portion 24. The stem portion 24 and each electrode of the electron gun 3 (cathode 21, first grid 20, second grid 19, focusing electrode) 18) are connected by lead wires 23, 23,..., Respectively, and a socket 25 connected to a power supply 26 by a lead wire 28 is provided outside the stem portion 24. Thereby, the cathode 21, the first grid 20, the second grid 19, the focusing electrode 18
To lead wire 28, socket 25, stem 24, lead wire
A required voltage is applied from a power source 26 via 23, 23,.

An internal conductive film 4 is applied to the inner surface from the neck portion 2 to the funnel portion 5, and an external conductive film 11 is applied to an outer surface of a required portion of the funnel portion 5. A conductive spacer 27 is provided between the internal conductive film 4 and the anode 17. Further, an anode button 6 is embedded at a required position of the funnel unit 5, and the anode button 6 is connected to a power supply 26 of the cathode ray tube 1 provided outside via a high-voltage lead wire 7. A high voltage from a power source 26 is applied to the anode 17 via the high voltage lead wire 7, the anode button 6, the internal conductive film 4, and the conductive spacer 27. Further, the deflection yoke 12 is connected to a power supply 26 via a lead wire 28,
A voltage is applied from a power supply 26 via a lead wire 28.

[0006]

When the conventional apparatus having the above configuration is started, the clamp 14 is charged to 1/5 to 1/2 of the high voltage applied to the anode 17, and the potential lower than this is applied. May discharge to the electromagnetic magnet 16. At the moment of this discharge, the potential of the clamp 14 drops to substantially zero.
Such a sudden change in potential on the outer surface of the neck portion 2 is as follows.
Influences even the electric potential of the inner surface of the neck portion 2 and the cathode ray tube 1
However, there is a problem that the reliability of the cathode ray tube device is reduced. To prevent this discharge in the tube, for example, a method of covering the clamp 14 with an insulating film is disclosed in JP-A-60-32306, but it is difficult to cover the entire clamp 14 with an insulating film. is there.

It is also conceivable that the fastening fitting 14 is directly grounded. However, in this case, since the potential difference from the high voltage applied to the internal conductive film of the neck portion 2 is large, dielectric breakdown in the glass of the neck portion 2 is concerned. Is done. The present invention has been made in view of the above circumstances, and a cathode ray tube capable of preventing discharge in a cathode ray tube or insulation breakdown of a neck portion by grounding a fastening member via a surge absorber element. It is intended to provide a device.

[0008]

The cathode ray tube device according to the present invention is characterized in that one end of the cathode ray tube device is connected to the ground potential at the other end of the surge absorber element to be connected to the ground potential.

[0009]

According to the present invention, when the clamp is grounded via the surge absorber element, the clamp is charged up to the limit voltage value of the surge absorber element, but the charge exceeding the limit voltage value is discharged. The charge can be kept constant.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a schematic sectional view showing a main part of a cathode ray tube device according to the present invention. In the drawing, reference numeral 1 denotes a known cathode ray tube including a neck portion 2, a funnel portion 5, and a panel portion 8 having an electron gun 3 on an end side in this order. A substantially donut-shaped deflection yoke 12 conforming to the shape of the cathode ray tube 1 is provided outside the vicinity of the connection between the neck portion 2 and the funnel portion 5.
The deflection yoke holder 13 is attached by fixing it with a clamp 14. Deflection yoke holder 13
In the figure, a flange portion 13b perpendicular to the outer surface of the cylindrical portion 13a is formed integrally with a central portion of the cylindrical portion 13a. Cylindrical part 13
A deflection yoke 12 is fitted in a portion of the panel portion 8 surrounded by a and the flange portion 13b. The cylindrical portion 13a on the electron gun 3 side is fixed by the clamp 14; the purity magnet 15 for color purity adjustment is provided on the base side of the flange portion 13b on the side of the electron gun 3; An electromagnetic magnet 16 for correction is provided. An inner conductive film 4 for electrically connecting the electron gun 3 to a power supply (not shown) is applied to an inner surface from the neck portion 2 to the funnel portion 5. The above is the same configuration as the conventional device.

In the apparatus of the present invention, a surge absorber element 29 is connected to the above-mentioned clamp 14 via a lead wire 28, and the other end of the surge absorber element 29 is grounded. As the limit voltage value of the surge absorber element 29, an appropriate value may be selected for the deflection yoke 12 in each cathode ray tube device so that the clamp 14 and the electromagnetic magnet 16 do not discharge. However, if this value is too low, there is a high possibility that the dielectric breakdown of the neck portion 2 will be caused.
It is desirable to be equal to or higher than KV.

[0012]

As described above, in the cathode ray tube device according to the present invention, the clamp is charged up to the limit voltage value of the surge absorber by grounding the clamp through the surge absorber. The present invention has excellent effects, for example, it is possible to prevent the discharge inside the cathode ray tube or the dielectric breakdown of the neck portion of the cathode ray tube.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a main part of a cathode ray tube device according to the present invention.

FIG. 2 is a schematic sectional view showing a conventional cathode ray tube device.

[Explanation of symbols]

 2 Neck part 5 Funnel part 12 Deflection yoke 13 Deflection yoke holder 13a Cylindrical part 13b Flange part 14 Clamping fitting 15 Purity magnet 16 Electromagnetic magnet 28 Lead wire 29 Surge absorber element

Claims (1)

(57) [Claims] In a cathode ray tube device in which a deflection yoke is held and a deflection yoke holder to which an electromagnetic magnet is attached is fixed to a cathode ray tube by a clamp, a surge absorber element whose one end is to be connected to a ground potential. A cathode ray tube device, wherein the other end of the cathode ray tube is connected to the clamp.