JPH04167341A - Electron gun for cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent breaking of a cathode and noise disturbance by using a metallic member as one part of an insulating support to the neck portion of which a plurality of electrodes are held and fixed. CONSTITUTION:Insulating supports 1, 7 are joined together by a metallic member 8 and shielded at their surfaces from each other between the respective embedding portions of electrodes 4, 5 by the member 8, Then secondary electrons readily emitted and growing on the surface of each support 1, 7 interposed between the electrodes 4, 5 where a high potential difference is generated are prevented by the metallic member 8. The danger of breaking of a cathode 6 and/or noise induction is reduced without causing bath peripheral discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electron gun for a cathode ray tube, and more particularly to an electron gun for a cathode ray tube that is effective in improving withstand voltage characteristics.

[Conventional technology]

Conventional electron guns for cathode ray tubes (hereinafter referred to as electron guns) are
As shown in the figure, an insulating support 1 and a plurality of electrodes 2, 3 .
4.5 degrees, and the electrodes 2 and 3 degrees 4.5 degrees are located at predetermined intervals. Therefore, the surface of the insulating support 1 is interposed between the embedded portions of the insulating support 1 of the electrodes 2, 3, 4.5.

When the cathode ray tube is in operation, a specified voltage is applied to each of the electrodes 2, 3, 4, and 5. In particular, a voltage of 20K is applied to the electrode 5.
A high voltage from V to 30KV (leprosy) is applied, and the electrode 4
Since a high voltage equivalent to 20 to 30% of that voltage is applied to the electrodes, the potential difference between the two electrodes increases from 14KV to 24KV1. :Monaru.

[Problem to be solved by the invention]

As mentioned above, in the conventional electron gun, a potential difference of about 14 KV to 24 KV occurs between electrodes where a high potential difference occurs, for example, between electrodes 4 and 5 in FIG. Furthermore, since the surface of the insulating support is interposed between the electrode embedded portions, during operation of the cathode ray tube, field emission electrons emitted from the low potential electrode 4 collide with the insulator surface and emit secondary electrons. Furthermore, there is a risk that so-called intratubular discharge, which leads to creeping discharge, may occur, and the cathode 6 may be damaged by the discharge energy at that time, and noise disturbances may be caused by the discharge current.

An object of the present invention is to provide an electron gun that does not cause damage to the cathode or cause noise disturbances due to discharge current.

[Means to solve the problem]

The present invention provides an electron gun for a cathode ray tube having a cathode, a plurality of electrodes, and an insulating support for holding and fixing the plurality of electrodes on a neck portion, in which a metal member is used as a part of the insulating support. There is.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram illustrating a first embodiment of the present invention.

In the first embodiment, as shown in FIG.
and the insulating support 7 are joined by a metal member 8, and the surface of the insulating support between the embedded portions of the electrodes 4 and 5 is blocked by this metal member, so that secondary electrons are not generated. There is no emission or growth, and creeping discharge can be prevented.

FIG. 2 is a schematic configuration diagram illustrating a second embodiment of the present invention.

In the second embodiment, as shown in FIG.
The metal member 8 used between the and the insulating support 7 and the electrode 4 are integrated, and the creeping discharge prevention effect is as follows.
This is equivalent to the first embodiment shown in FIG.

FIG. 4 is a distribution diagram of creeping discharge initiation potential difference.

As shown in FIG. 4, compared to the conventional electron gun, the electron gun of this embodiment can improve the level of withstand voltage characteristics by about 5 KV.

〔Effect of the invention〕

As explained above, by using a metal member as a part of the insulating support, the secondary electrons, which are easily emitted and grow on the surface of the insulating support interposed between the electrodes where a high potential difference occurs, are transferred to the metal. It is blocked by a member to prevent creeping discharge,
This has the effect of reducing the risk of cathode damage and noise disturbances.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram explaining a first embodiment of the present invention, FIG. 2 is a schematic configuration diagram explaining a second embodiment of the invention, and FIG. 3 is an example of a conventional electron gun. A schematic configuration diagram to explain,
FIG. 4 is a distribution diagram of creeping discharge initiation potential difference. 1.7... Insulating support body, 2, 3, 4.5... Electrode, 6... Cathode, 8... Metallic member.

Claims (1)

[Claims] A cathode ray tube electron gun having a cathode, a plurality of electrodes, and an insulating support for holding and fixing the plurality of electrodes on a neck portion, characterized in that a metal member is used as a part of the insulating support. Electron gun for cathode ray tubes.