JPS6332212B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a getter flash method for cathode ray tubes in which a getter agent is deposited on the inner surface of the tube, and more particularly to a method for preventing cracks in the tube body that occur during getter flash. be.

Generally, in television picture tubes, for example, a getter container filled with a getter agent is installed inside the tube in order to maintain a high vacuum inside the tube for a long time and to maintain good electron emission from the cathode. In the exhaust process, the getter agent is scattered by high-frequency heating to form a getter film.

FIG. 1 shows an outline of a conventional cathode ray tube. Tube 1
A support piece 3 is attached to the electron gun 2 set in the neck portion 1a of the
is attached, and a getter device 4 is fixed to the tip of this support piece 3, and this getter device is set on the inner surface of the tube body 1. The getter device 4 is brought into contact with a conductive coating 6 applied to the funnel portion 1b via a spring material 5.

As shown in FIG. 2, this getter device 4 includes:
A getter container 4a is filled with a getter agent 4b, and a getter flash coil 7 is inserted from the outside.
The getter device 4 is heated to approximately 900 to 10,000°C. The coil 7 is connected to a high frequency heating device (not shown), and a high frequency current flows through the coil 7. The getter agent 4b of the getter device 4 heated by high frequency becomes metal vapor and scatters as shown by arrow A.
It is deposited on the inner surface of the tube body 1. However, if the vapor is deposited on the fluorescent surface 9 formed on the inner surface of the panel 8, the brightness may decrease or the brightness may become uneven.
Attach Getter Shield 4c to the front of a. In this way, the scattered getter agent 4b
Although most of the getter agent is deposited on the funnel portion 1b, a large amount of the getter agent is scattered particularly on the funnel portion on the side where the getter device 4 is attached.

When the getter flash is performed by the high-frequency heating, a potential difference is generated between the getter film 10 formed by vapor deposition of the getter agent 4b and the getter device 4, and the potential of the getter film 10 ranges from several volts to several volts. The voltage may rise to 100 volts, causing a creeping discharge between the spring 5 and the spring 5. A conductive substance 6 is coated on the inner surface of the funnel portion 1b, but due to contact resistance between the spring 5 and the conductive substance 6 and resistance of the conductive substance 6 itself, the getter device 4 and the getter film 10 are This creates a potential difference between the two.
If such a potential difference exists, the above-mentioned creeping discharge will occur due to the output of the high-frequency heating device, the shape of the getter flash coil 7, the coating state of the conductive substance 6, etc., and the spring 5 will come into contact with it. Cracks 12 occur on the glass surface, and when creeping discharge occurs for a long time, the tube body 1 may be completely damaged, which is very dangerous and has the disadvantage of causing a very large economic loss. . In addition, in FIG. 1, 13 is a terminal for anode voltage supply attached to the tubular body 1.

This invention was made to eliminate the above-mentioned drawbacks, and provides a method for effectively preventing damage to the tube by grounding the inner surface of the tube during high-frequency heating of the getter agent. .

An embodiment of the invention shown in FIG. 3 will be described below.

In FIG. 3, the tube body 1 is attached to the getter flash stand 16, the getter device 4 is heated with high frequency by the getter flash coil 7, and the tube body 1 is heated with high frequency by the getter flash coil 7.
The getter film 10 is formed by depositing the getter agent 4b on a predetermined portion 15 of the inner surface of the tube. The button-shaped terminal 13 for supply is grounded.
In this way, the predetermined portion 15 is grounded via the terminal 13, and even if high-frequency heating is performed in this state, the potential of the getter film 10 will not increase, and the potential between the getter film 10 and the spring 5, that is, the getter device, will not increase. 4, creeping discharge will no longer occur.

Note that although the case of a television picture tube has been described above, the present invention can be similarly applied to other cathode ray tubes.

As explained above, according to the present invention, no creeping discharge occurs during getter flushing, so there is no damage to the tube body due to creeping discharge.
This has the effect of improving work stability and reducing manufacturing costs due to improved yield.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing an example of a conventional cathode ray tube, Figure 2 is a vertical cross-sectional view showing the main parts of Figure 1, and Figure 3 is a vertical cross-sectional view showing an example of a conventional cathode ray tube.
The figure is a longitudinal sectional view showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Tube body, 4... Getter device, 4b... Getter agent, 7... Coil for getter flash, 13...
Anode voltage supply terminal, 15...predetermined portion. In addition,
In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1 A cathode ray tube in which a getter device containing a getter agent is set inside a tube body, and a predetermined portion of the inner surface of the tube body is grounded, and the getter device is heated with high frequency to deposit the getter agent on the predetermined portion. Getter flash method.