JPS6212622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a withstand voltage processing apparatus that can perform effective withstand voltage processing without impairing the characteristics of a cathode ray tube.

Hereinafter, the content of the present invention will be explained in the case of a withstand voltage processing device for a color cathode ray tube.

Figure 1 shows an outline of the electrode structure in a conventional color cathode ray tube. In the figure, 1 is a glass bulb, 2 is an anode button to which high voltage is supplied, and 3 is a conductive film formed on the inner wall of the glass bulb 1. , 4 is an anode connected to the conductive film 3 via a spring, and a high voltage is supplied from the anode button 2 via the conductive film 3 and the spring. Further, 5 is a third electrode arranged opposite to the anode 4, 6 is a second electrode, and 7 is a third electrode arranged opposite to the anode 4.
8 is a first electrode, 8 is a cathode electrode, and 9 is a heater electrode, and these electrodes are led out from the back of the glass bulb 1 via lead wires 10, respectively. In such color cathode ray tubes, a high voltage of several tens of kilovolts to several tens of kilovolts is applied to the anode 4. A high voltage is applied to each electrode to withstand voltage. The withstand voltage treatment consists of the anode 4 and the next stage electrode 5.
The withstand voltage treatment between the third electrode 5, the second electrode 6, and the first electrode 7 can be considered separately. Conventionally, these two types of withstand voltage treatments are performed by applying the above-mentioned high voltage to the anode 4. In other words, by applying a high voltage to the anode 4, a spark is generated between it and the third electrode 5,
For this reason, the potential of the third electrode 5 increases, and withstand voltage treatment between the second electrode 6 and the first electrode 7 is performed using this increased potential of the third electrode 5. At this time, a resistance element is connected to the outside in order to increase the potential of the third electrode 5. A feature of such a conventional method is that it has one type of power source for applying a high voltage to the anode 4, so that two types of withstand voltage treatments can be performed simultaneously. However, since the potential of the third electrode 5 depends on an external resistance element and a spark current generated between the third electrode 5 and the anode 4, there is a drawback that the potential is not constant. That is, when too high a voltage is induced in the third electrode 5, sparks are induced from the third electrode 5 to the cathode electrode 8 or the heater electrode 9,
This would have caused damage to the heater electrode 9 or the cathode electrode 8.

This invention prevents damage to the heater section or the cathode section and performs effective withstand voltage treatment by making the potential induced in the third electrode constant.

Hereinafter, this invention will be explained with reference to FIG. 2, which is one embodiment. In FIG. 2, 11 is the third electrode 5
12 is a discharge gap connected in parallel to the resistance element 11, and 13 is a high voltage source that supplies high voltage to the anode 4. Further, the other electrodes are directly grounded. Note that the resistance element 11 is for inducing a high voltage in the third electrode 5 when a spark occurs between the third electrode 5 and the anode 4, and a resistance of several kilohms is usually sufficient. The discharge gap 12 discharges when the voltage induced by the resistive element 11 is too high to keep the voltage constant, and has a discharge starting voltage of about 10 kilovolts.
With this configuration, even if an excessively high voltage is generated at the third electrode 5, a spark can be caused by the discharge gap 12 to induce a constant voltage at the third electrode 5, and the heater electrode 9 or cathode electrode 8
damage can be prevented.

As explained above, according to the present invention, the intended purpose can be achieved with simplicity, and the practical value of the present invention is great.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the electrode structure of a conventional color cathode ray tube, and FIG. 2 is a schematic diagram showing the configuration of a withstand voltage processing device according to an embodiment of the present invention. In the figure, 2 is an anode button, 4 is an anode, 5 is a third electrode, 6 is a second electrode, 7 is a first electrode, 8 is a cathode electrode, 9 is a heater electrode, 10 is a lead wire, 1
1 is a resistance element, 12 is a discharge gap, and 13 is a high voltage source. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. Withstand voltage of a cathode ray tube, characterized in that a parallel circuit of a resistance element and a discharge gap is connected to one electrode or a plurality of electrodes of the cathode ray tube, and a high voltage is applied to the anode of the cathode ray tube. Processing equipment.