JPS5912542A - Method for withstand voltage treatment of cathode ray tube - Google Patents

Abstract

PURPOSE:To enable an efficient withstand voltage treatment process as well as an effective discharge treatment, by providing the direct current high voltage treatment process for a period of a specific time prior to the pulsating high voltage treatment process. CONSTITUTION:The cathode ray tube which has already been treated in the cathode aging process 1 is shifted to the withstand voltage treatment process 2. In the first stage of the withstand voltage treatment process 2, a direct current high voltage treatment process 11 is provided. In this stage, the electrodes to be applied with low voltage including the heater for the electron gun are grounded, and such a direct current high voltage 1.1-1.5 times as high as the maximum rated voltage of the cathode ray tube is applied from the anode for 30sec to 2hr to the electrodes to be applied with high voltage, e.g., the anode voltage. In the second stage, a pulsating high voltage treatment process 12 is provided. In this stage, a pulsating high voltage is applied, while the electrodes to be applied with low voltage including the heater for the electron gun are grounded. The cathode ray tube is then shifted to the next inspection process 3. By such a method, the withstand treatment process can be carried out with very high efficiency.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a withstand voltage treatment method for cathode ray tubes, and particularly relates to a withstand voltage treatment method for cathode ray tubes that enables efficient withstand voltage treatment. .

[Technical background of the invention]

The withstand voltage treatment for cathode ray tubes is generally performed by grounding the low voltage application electrodes, including the heater of the electron gun, and applying a pulsed voltage of 2 to 3 times the maximum rated voltage during normal operation to the high voltage application electrode to which the anode voltage is applied. A pulsed high-voltage treatment process that applies a high voltage is used to burn off foreign objects and burrs that are expected to exist on the surfaces of the multiple electrodes that make up the electron gun, preventing the generation of floating electrons during operation and This is done to prevent electrical discharge.

Next, an example of a conventional withstand voltage treatment method for a cathode ray tube will be explained with reference to FIG. In 2), the low voltage application electrode including the heater of the electron gun is grounded, and the high voltage application electrode to which the anode voltage is applied is connected to the anode terminal using an induction coil or Tesla coil to generate a pulse of 2 to 3 times the maximum rated voltage. A pulsed high voltage treatment step (1z) of applying a high voltage is performed by increasing the voltage sequentially according to a predetermined time schedule or repeating it several times in succession, and then an inspection step (3) is performed.

[Problems with background technology]

However, with this withstand voltage treatment method, the electrostatic attraction force due to the pulsed high voltage is short-lived, so foreign matter on the electrode surface and
A long period of application is required to burn off the burrs by electric discharge. In addition, if sufficient burnout is not possible, there is a problem in that the withstand voltage deteriorates in the inspection step (3). Furthermore, there is also the problem that long-term application tends to cause damage to the electrodes and neck glass due to localized discharge.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and by performing DC high voltage processing before the pulsed high voltage processing step, the discharge and processing by the subsequent pulsed high voltage processing step can be effectively performed. The purpose of the present invention is to provide a withstand voltage treatment process for cathode ray tubes that can be treated with high voltage.

[Summary of the invention]

That is, in the withstand voltage treatment process of cathode ray tubes, the present invention can perform the withstand voltage treatment process extremely efficiently by providing a DC high voltage treatment process for 30 seconds to 2 hours before the pulsed high voltage treatment process. This is a possible voltage resistance treatment method for cathode ray tubes.

[Embodiments of the Invention] Next, a method for treating a cathode ray tube withstand voltage according to the present invention will be explained with reference to FIG. In the figure, steps that are the same as those of the conventional method are indicated by the same reference numerals.

That is, the cathode ray tube that has undergone the cathode aging step (1) is moved to the withstand voltage treatment step (2), and this withstand voltage treatment step (
In the first stage of step 2), the low voltage application electrode including the heater of the electron gun is grounded, and a direct current of 11 to 1.5 of the maximum rated voltage of the cathode ray tube is applied from the anode terminal to the high voltage application electrode to which the anode voltage is applied. A DC high voltage treatment step (Ill) is provided in which high voltage is applied for about 30 seconds to 2 hours.

The low voltage application electrode including the heater of the electron gun is grounded in the latter stage, and a pulse height of 2 to 3 times the maximum rated electrode is applied from the anode terminal to the high voltage application electrode to which the anode voltage is applied using an induction coil, Tesla coil, etc. A pulse-like high voltage treatment step 0z for applying a voltage is performed by increasing the voltage sequentially according to a predetermined time schedule and repeating it several times in succession, and then an inspection step (3) is performed.

According to the withstand voltage treatment method of this embodiment, the pulsed high voltage treatment is performed after foreign particles, burrs, and other protrusions on the electrode surface are excited to a state where they are easily discharged by the electrostatic attraction force generated by the DC high voltage treatment. The pulsed high-voltage treatment can sufficiently burn away foreign matter on the electrode surface even for a short time, and since the discharge time is short, damage to the electrode and neck glass due to discharge can be prevented. .

According to experiments, DC high voltage processing is improved by 3 times compared to conventional ones.
If the treatment is carried out for 0 minutes, the pulsed high voltage treatment time can be reduced to 1/3. In addition, it was observed that the number of post-processed culms such as the inspection process (3) that caused deterioration in pressure resistance was reduced to 1/2 to 1/3.

In addition to the above-mentioned embodiments, a pulsed high-voltage treatment step may be further provided in the preceding stage. In addition, this high voltage treatment step (12
It goes without saying that repeating step 1 is even more effective. Furthermore, although a high-voltage electrode treatment in which a high voltage is applied from an anode terminal is shown, it is of course applicable to other electrode treatments as well.

〔Effect of the invention〕

As described above, according to the method for treating cathode ray tubes with withstand voltage of the present invention, the withstand voltage characteristics of cathode ray tubes are improved and damage to the cathode ray tubes can be prevented, and its industrial value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional withstand voltage processing method for a cathode ray tube, and FIG. 2 is a block diagram showing an embodiment of the withstand voltage processing method for an ULT ray tube according to the present invention. 1. Cathode aging process 2. Voltage resistance treatment process 3
...Inspection process 11...DC high voltage treatment process 12...Pulse high voltage treatment process Agent Patent attorney Inoue - Male

Claims (1)

[Claims] A withstand voltage treatment method for cathode ray tubes, characterized in that a DC high voltage treatment step for 30 seconds to 2 hours is provided before a pulsed high voltage treatment step in the withstand voltage treatment step for cathode ray tubes.