JPS6138569B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a high voltage processing method for cathode ray tubes.

In the manufacture of cathode ray tubes, such as color picture tubes, it is common to flash the getter after completing the evacuation process, then perform a high voltage treatment, and then perform a characteristic test. If this high voltage treatment is not carried out sufficiently, a discharge phenomenon may occur within the tube after it is assembled into a television receiver, damaging the cathode of the picture tube or damaging the electric circuit of the receiver. be. In particular, recent TV receivers use a voltage of 27
It is often operated at ~30KV, which is an important issue.

Conventional high voltage processing involves short-circuiting both output ends 3a and 3b of a high voltage generation circuit 2 connected to power supply ends 1a and 1b via a discharge gap 4, as shown in the first figure, and short-circuiting both output ends 3a and , 3b are directly connected to the cathode terminal 6 and anode terminal 7 of the cathode ray tube 5 to be processed, and a high voltage is applied between the anode (not shown) in the tube 5 and each electrode constituting the cathode. In this case, the above-mentioned high voltage generating circuit 2 is represented by a step-up transformer in the figure, but various types such as an induction coil and a Tesler coil are in practical use.

Performing high voltage processing in this manner has the advantage that the upper limit of the voltage to be applied can be controlled by the discharge gap 4. However, if this high voltage is continuously applied, a continuous discharge will occur in parts of the tube with weak withstand voltage, and the resulting heat will cause glass to be ejected from the discharge part and metal evaporated from the discharge part to be released. There is a risk of spatter on the neck or cracks on the neck glass.

The present invention has been made to eliminate these drawbacks of the prior art, and by providing the main discharge gap and the sub-discharge gap in separate series, it eliminates the harm of continuous discharge as well as excessive voltage. .

The details of the present invention will be explained below with reference to FIG.

This circuit short-circuits both output ends 3a and 3b of a conventional high voltage generation circuit 2 connected to power supply ends 1a and 1b via a main discharge gap 8, and connects one output end 3a to a sub-discharge gap 9. The other output end 3b is connected directly to the anode terminal 7 of the cathode ray tube 5 to be processed. By adjusting the main discharge gap 8, both output terminals 3
The maximum voltage between a and 3b is controlled, and the combined impedance on the load side is controlled by adjusting the sub-discharge gap 9, so that only the high peak pulse is selectively applied between the electrode terminals 6 and 7.

As a result, continuous discharge during high voltage processing is prevented, which is a drawback of the prior art described above. Outgassing, sputtering or cracking of the glass are prevented. In addition, even if the wiring on the load side is short-circuited or the degree of vacuum inside the cathode ray tube 5 is insufficient, the provision of the auxiliary discharge gap 9 protects the high voltage generation circuit and ensures safe and reliable operation. It is possible to maintain stable operation.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of a conventional high voltage processing method for a cathode ray tube, and FIG. 2 is a circuit diagram showing an embodiment of the high voltage processing method for a cathode ray tube according to the present invention. 2...High voltage generation circuit, 3a, 3b...Output end, 5...Cathode ray tube, 6...Cathode terminal, 7...Anode terminal, 8...Main discharge gap, 9...Sub discharge gap.

Claims (1)

[Claims] 1. A cathode ray tube characterized in that both output ends of a high voltage generation circuit are short-circuited via a main discharge gap, and both output ends are connected to a cathode terminal and an anode terminal of the cathode ray tube via a sub discharge gap. High voltage processing method.