JPS5827473Y2 - color picture tube - Google Patents

Description

[Detailed description of the invention] The present invention relates to a color picture tube, and in particular to stabilization of electron radiation.
The object of the present invention is to provide a color picture tube that has a longer life and improved voltage resistance against sparks.

As shown in FIG. 1, in a conventional color picture tube, a panel 1 serving as an image receiving section and a funnel 2 on the electron gun side are made of frit glass 3.
The funnel side has a neck glass 2' into which the electron gun 4 is inserted, and the end thereof is sealed with a stem having a lead for electrically conducting with an external circuit.

In this structure, the color picture tube is a high-vacuum electron tube, so in order to maintain the degree of vacuum, the funnel getter 5 or the neck getter 6, or both if necessary, are generally operated as shown in FIG. It is attached to the top of the gun and is flushed with a getter after exhaust to maintain a high degree of vacuum.

In such a state, the degree of vacuum is high in the panel 1 and funnel 2, but the neck glass 2' has a hot cathode, especially in the electron gun 4, and in some cases sparks between the electrodes of the electron gun, etc. Since a large amount of gas is released, the degree of vacuum is poor.

In particular, in a picture tube that has been evacuated and the getter flushed, the gas inside the tube moves freely, and those that happen to hit the flushed getter film are adsorbed. Gas generated by heating, ion bombardment, decomposition of electron radioactive materials, etc., especially in the hot cathode part of the gun 4, is not adsorbed by the getter film flushed to the funnel part, creating a difference in the degree of vacuum between this part and the funnel part. .

One example that proves this is when electrons from the cathode hit the gas emitted from the electrode during an aging process, etc., and the electrons are ionized and cause ion bombardment, causing problems.

If this part is in a high vacuum like the funnel part,
Such a phenomenon cannot occur.

Furthermore, such a gas destroys the cathode as described above, or otherwise causes considerable damage to the electron emitting material of the cathode during the aging process, which often results in a shortened lifespan.

In other words, by appropriately treating the gas released during the aging process, etc., a picture tube with stable parts and a long life can be obtained.

The present invention has been devised in view of the above circumstances, and details of the present invention will be explained below with reference to drawings showing one embodiment thereof.

In today's three-color picture tubes, the cathode is located at the apex of an equilateral triangle, which was the conventional △ method, but due to ease of adjustment, simplification of installed parts, and improvements in manufacturing technology, the cathode is arranged in a straight line. There has been a shift towards in-line methods, and the present invention is particularly suitable for such electron guns.

As shown in Figures 2 to 4, the getter 7 is attached to the electron gun 4, and its attachment position is on the low voltage side of the electron gun, and the distance between the neck glass 2' and the electron gun is the greatest. It is preferable to use the intermediate electron gun 4'.

That is, as mentioned above, the electron gun cathode is in a straight line, and the neck glass 2' is of type 1, so naturally the distance between the intermediate electron gun 4' and the neck glass 2' is the largest.
The space required for mounting the getter 7 and the getter flash is sufficient.

Further, as mentioned above, it goes without saying that it is advantageous to attach the getter 7 to a place where the temperature is likely to rise as much as possible and where gas is likely to be generated, such as the cathode.

The electron gun with the getter 7 attached at such a position is inserted into the neck glass of the picture tube, and after sealing with the stem part, the electron gun is evacuated and the getter is flashed.

In this case funnel getter 5 or neck getter 6
may be flushed simultaneously with the getter 7 of the present invention, but better results can be obtained if the getter 7 of the present invention is flushed later.

This is because the capacity of Getter 7 is very small, only a few mg compared to 100 mg or more for Funnel Getter 5, so if Getter 7 is flushed first, the amount of water released when flushed from Funnel Getter 5, etc. This is because the flushed getter film 8 of the regetter 7 is reduced by the gas, and the gas adsorption ability is reduced.

When aging is performed next in this way, the gas coming out of the cathode has a higher probability of hitting the getter film 7 of the present invention than going to the funnel part and hitting the getter film, so the gas molecules in the cathode part will decrease. The degree of vacuum will improve and damage to the cathode etc. will disappear.

In this way, if the getter 7 makes it possible to gas-treat the parts of the electron gun that emit a lot of gas during aging, even if the effectiveness of the getter film 7 decreases in this step, the picture tube will not be used in the subsequent use of the picture tube. Gas release due to aging etc. will not have any adverse effects unless there is a serious abnormal phenomenon.

Since the cathode is not damaged during aging, a color picture tube with high reliability, long life, and stable quality can be obtained.

Additionally, it has been found that the present invention provides other advantages.

In other words, neck glow often occurs between the high-voltage third grid electrode and the neck glass, which causes sparks between the electrodes, which can destroy the television receiver circuit and damage the picture tube electrodes, especially the cathode. It was causing destruction.

However, by forming a getter film 8 on the inside of the neck glass 2' by flashing the getter 7 installed according to the present invention and connecting this to the ground electrode, neck glow and the like will no longer occur.

This neck glow occurs because an electric field is generated between the foreign matter attached to a part of the inside of the neck glass and the high-voltage third grid electrode, and the foreign matter is excited and generates cold emissions, which causes the glow. This problem can also be solved by connecting the getter film to the ground electrode.

To take out this ground electrode, for example, a getter contact piece may be brought out and brought into contact with one end of the heater of the stem.

As shown in Figure 3, if the getter 7 is used with too wide directivity in the direction of the tube axis, it will cause a wide flash especially on the high voltage side, which is dangerous. It is better to use an appropriate one, taking into consideration the following.

In addition, in the above, as shown in Figures 2 to 4, 3
We are talking about a type of electron gun in which the electron gun is independent. For example, the cathode is independent, but the It goes without saying that the present invention can be similarly applied to an electron gun in which the second grid electrode etc. are integrally constructed, and the same effects can be expected.

[Brief explanation of the drawing]

Figure 1 is a schematic sectional view of the main parts of a conventional color picture tube;
The figure is a side view of essential parts of the color picture tube of the present invention, and FIGS. 3 and 4 are sectional views taken along the Y-Y' line and the XX' line, respectively. 4...Electron gun, 4'...Middle electron gun, 5...Neck getter, 6...Funnel getter, 7... Getter according to the present invention, 8...Getter film.

Claims (1)

[Scope of utility model registration request] Equipped with an electron gun having multiple cathodes arranged in a straight line, a getter is attached to the low-voltage side of the electron gun at the part where the distance from the neck glass is almost the maximum, and the flash of this getter causes the inside of the neck glass to be A color picture tube characterized in that it has a getter film formed thereon.