JPH0511637Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to the structure of an electron gun for a picture tube.

[Technical background of the invention]

A structure in which an electrode voltage is obtained by a resistor provided inside or outside the tube in an electron gun for a picture tube is conventionally known. The conventional method will be explained with reference to the drawings. 1st
The figure shows the basic structure of such an electron gun. Although not particularly shown in FIG. 1, the electron gun 1 and the resistor 2 are placed in a vacuum container. The electron gun in Figure 1 generally has a high voltage (10
~30KV) is applied, and a relatively low voltage (several KV) is applied to G5 (1-2) to focus the electron beam narrowly. Here, the high voltage of G6 (1-1) is supplied independently from the fluorescent surface side, but the high voltage of G5 and others is supplied from the stem pin at the end of the neck portion in which the electron gun is disposed. That is, it is impossible to supply the maximum high voltage to G6 from the stem pin because it would induce interelectrode discharge. However, since the focusing voltage (hereinafter referred to as focus voltage) is a high voltage of several kilovolts, discharge is likely to occur, so normally an insulator or the like is attached around the stem pin to prevent discharge as much as possible. Furthermore, the focus voltage itself is generated from a high voltage using a resistor. On the other hand, in the structure shown in Figure 1, the focus voltage is obtained by dividing the high voltage using a resistor, so the voltage at the stem pin can be lowered, which reduces discharge accidents at the stem pin. can. In addition, in recent picture tubes, there is a tendency to increase the focus voltage to improve the performance of the electron gun, but there is a limit to increasing the stem pin voltage, and there was a restriction that the focus voltage could not be increased. The advantage is that it can be solved in this way. Furthermore, since the focus voltage is obtained by dividing by resistors, there is an advantage that the focus voltage circuit can be omitted and the circuit cost can be significantly reduced.

[Problems with background technology]

As an example of resistance division of the focus voltage, there is a structure in which a focus voltage is obtained by forming a resistor film on an insulating glass for electrode support, as shown in Japanese Patent Laid-Open No. 53-89360. In such a structure, since the voltage supply lead wire is not electrically connected to the resistor film in advance, discharge or the like occurs from the connection between the lead wire and the resistor film.

Furthermore, when the glass for fixing the electrodes is made of a resistor, there is a problem in that the voltage applied to the final electrode G6 (1-1) is particularly high, which causes surface discharge and the like, making it difficult to obtain good results.

Therefore, as shown in FIG. 2, a glass 5 having a high resistivity (hereinafter referred to as high-resistance glass) is usually coated on the surface of a glass 4 having a relatively low resistivity (hereinafter referred to as a resistor glass). It is used as The parts that fix each electrode of the electron gun are used by removing the high-resistance glass coating part, as shown in FIG.

Also known is a method of providing grooves on the surface of high-resistance glass 5 coating resistor glass 4. As shown in FIG. 3, a lead 6 for taking out voltage is attached to a groove 7 provided on the surface of the high-resistance glass to obtain a focus voltage.

The disadvantage of this structure is that the glass surface of the resistor is exposed to the outside. Therefore, despite various cleaning methods, surface leakage or discharge tends to occur, and the focus voltage is not constant, which poses a serious problem in practice.

[Purpose of invention]

An object of the present invention is to provide an electron gun for a picture tube that is easy to manufacture and has a resistor glass that provides a reliable electrode potential.

[Summary of the idea]

In the present invention, a member for extracting or supplying the electrode potential is assembled in advance in the resistor glass, and electrical continuity with the electrode is established during or after the electrode is fixed.

[Example of idea]

The present invention will be explained using drawings. FIG. 4 shows a preferred embodiment of the present invention. In this embodiment, a high-resistance glass 5 and a resistive glass 4 have a two-layer structure, and a lead wire 6 for supplying voltage is partially buried in the resistive glass 4 side so that electrical continuity can be obtained. It is preferable to embed the lead wires 6 at the time of forming the resistive glass. The surface of the resistor glass 4 is coated with high resistance glass to prevent leakage, discharge, etc. on the surface.

It is preferable to fix each electrode by baking the high-resistance glass 5 side as in normal beading, mechanically fixing it, and then welding the lead wire 6 to a suitable electrode. According to this method, each electrode is electrically insulated by the bead glass, and a voltage is applied only to the necessary electrodes.

FIG. 5 shows another preferred embodiment of the present invention. FIG. 5 shows a resistive glass used in a preferred embodiment of the present invention. The resistance glass 4 has a metal member 8 partially embedded in an appropriate part, and the surface is coated with a high resistance glass 5. Therefore, even if a voltage is applied to the metal member 8, there is no risk of surface leakage or the like. Further, it is preferable that the metal member 8 has a wide surface and that the electron gun electrode 1 is welded to the metal member 8.

In yet another embodiment of the present invention, parts other than those used as resistors may be made of high-resistance glass, and some electrodes may be beaded in the usual manner.

Note that although the above embodiments were explained using a so-called QPF type electron gun, other types of electron guns may also be used.
Of course, the present invention can also be applied to UPF type and BPF type electron guns.

[Effect of idea]

As described above, according to the present invention, an inexpensive and highly reliable electron gun can be obtained, which has a very high industrial value.

[Brief explanation of drawings]

Figure 1 is a schematic diagram for explaining the principle of resistance division, Figures 2 and 3 are schematic cross-sectional views of the main parts of a conventional resistance division electron gun, and Figures 4 and 5 are the invention of the present invention. FIG. 2 is a schematic cross-sectional view of main parts showing an embodiment of the present invention. 1... Electrode, 2... Resistance, 3... Variable resistance, 4
... Resistance glass, 5 ... High resistance glass, 6 ... Lead, 7 ... Groove, 8 ... Metal member.

Claims (1)

[Scope of utility model registration request] An electron gun for a picture tube comprising a plurality of electrodes and an electrode supporting glass that supports and fixes these electrodes and has therein a voltage divider including a resistor, the electrode potential being applied to at least one electrode being obtained by the voltage divider. In the voltage divider, a voltage extraction member electrically embedded and connected to the resistor is provided in advance, and the voltage divider is coated with an insulator except for a connection portion of the voltage extraction member to the electrode. Characteristic picture tube electron gun.