JPS63307640A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To enhance the withstand voltage characteristic between electrodes of an electron gun by applying high voltage to the electrodes and preforming processing while heat is applied to the electrodes of electron gun installed at the neck part. CONSTITUTION:The low voltage side electrode 1 of an electron gun installed at the neck part of a cathode-ray tube 10 is connected with a negative terminal of a high voltage generating device 3 through an inner lead 2, while the high voltage side electrode 4 with the positive terminal of the same device through interior fitted graphite 5 and an anode button 6. High frequency current is supplied to a heating coil 7 from a high frequency power supply 8 to heat the electrodes 1, 4 to an appropriate temp. It is easy to release heat electrons from the low voltage electrode, and occluded gas from the electrodes is released with heating, so that the gas is ionized by the heat electrons to bring about the state in which electric discharge occurs easily. This provides a cathode-ray tube with good withstand voltage characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a cathode ray tube, and particularly to a high voltage treatment method for improving the withstand voltage characteristics between electron gun electrodes.

[Conventional technology]

Conventionally, in the manufacturing process of cathode ray tubes, approximately 40KV was applied between the electrodes after the cathode ray tube was evacuated and sealed in order to improve its withstanding voltage characteristics.
A so-called electrical conditioning process is performed in which microprotrusions on the electrodes are welded and evaporated by applying a high voltage of 70KV to 70KV and forcibly generating discharge.

[The gap that the invention attempts to solve]

In the conventional high-voltage processing method described above, for example, if the gap length between the electron gun electrodes becomes large, the applied voltage must be increased to increase the probability of discharge during processing, and as a result, the processing equipment becomes large-scale. Processing time also increases. or,
If a plurality of interelectrode gaps that require high-voltage processing exist in the electron gun, there is a drawback that it becomes difficult to obtain desired withstand voltage characteristics.

[Means for solving problems]

The present invention involves disposing a high-frequency induction heating coil for heating the electrodes in the neck of the cathode ray tube, supplying high-frequency current to raise the temperature of the electrodes to an appropriate temperature, and applying a high voltage between the electrodes for processing. Features.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is an overall configuration diagram of a first embodiment of the present invention. Electron gun low voltage side electrode 1 provided at the neck of the cathode ray tube 10
is connected to the negative terminal of the high voltage generator 3 via the inner lead 2, and the high voltage side electrode 4 is connected to the positive terminal of the high voltage generator via the internal graphite 5 and the anode button 6. The heating coil 7 is supplied with a high frequency current from a high frequency power source 8 and heats the electrodes 1 and 4 to an appropriate temperature.

FIG. 2 is an overall configuration diagram of a second embodiment of the present invention. In an electron gun having different electrode gaps, the part with the longest gap length is heated, so that the same processing effect as with other electrode gaps can be obtained.

In this way, in the present invention, since the electrodes are heated during high voltage processing between the electrodes of the electron gun, thermionic electrons from the low voltage electrodes are easily released, and the storage gas from the electrodes is heated. Since the gas is emitted by thermionic electrons, the gas is ionized and becomes in a state where discharge is extremely likely to occur, making it possible to perform more sufficient conditioning. At this time, conditions such as electrode temperature, high voltage processing voltage 2 processing time, etc. may be optimally selected depending on the interelectrode gap, electrode structure, and shape.

〔Effect of the invention〕

As explained above, the present invention employs a high voltage treatment method while heating the electrodes, so the gap length is shortened due to thermal expansion of the electrodes, and discharge is caused by releasing the occluded gas of the electrodes. Due to the synergistic effect of easily leading to , the discharge starting voltage becomes lower. That is, it becomes possible to perform more sufficient high voltage processing, and it is possible to manufacture a cathode ray tube with good withstand voltage characteristics. Further, in the case of an electron gun having a plurality of electrode gaps, especially an electron gun having an unbalanced gap configuration, it is possible to easily improve a specific electrode gap to a desired withstand voltage characteristic.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a first embodiment of the present invention, and FIG. 2 is an overall configuration diagram of a second embodiment of the invention. 1...Low voltage side electrode, 2...Inner lead, 3...
...High voltage generator, 4...High voltage side electrode, 5...
Internal graphite, 6... Anode button, 7... Heating coil, 8... High frequency power supply, 10... Braun tube.

Claims (1)

[Claims] A method for manufacturing a cathode ray tube, characterized in that processing is performed by applying a high voltage between the electrodes while heating the electrodes of an electron gun disposed in the neck.