JPH1167097A - Method for processing cathode-ray tube under high pressure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid damage to electron-gun electrodes and to neck glass to enhance withstand voltage characteristic by varying in each processing step the pulse widths of the induction transformer outputs of plural power supplies which generate high application voltages. SOLUTION: The anode side terminal 9 and cathode side terminal 8 of an induction transformer 7 are connected, respectively, to the anode terminal 5 of a cathode-ray tube 2 and to a gold terminal conducting socket 3 to which each electrode other than an anode is electrically connected. An output voltage which the induction transformer 7 applies to the anode terminal 5 of the cathode-ray tube is made higher as processing steps proceed, and withstand voltage characteristic is enhanced by increasing the voltage in steps. At the same time, output pulse width in each step is decreased in steps to suppress discharge power to avoid damage to electron gun electrodes, etc. When output pulse width in the final processing step is reduced to one-fifth, the output voltage can be raised by several KV to over ten KV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure processing method for improving the withstand voltage characteristics of a cathode ray tube.

[0002]

2. Description of the Related Art Hitherto, in order to obtain a good withstand voltage characteristic of a cathode ray tube, a high pressure treatment for applying a higher voltage to the cathode ray tube than in an actual use state has been performed.

FIG. 3 shows an example of a connection at the time of the high-pressure processing. An induction transformer 1 is used as a power supply for applying a high voltage. Normally, the cathode terminals of a cathode ray tube 2 are connected by a socket 3 in which all terminals are electrically connected. The anode terminal 5 of the cathode ray tube 2 is connected to the anode terminal 6 of the induction transformer 1.

FIG. 4 shows a conventional high-voltage processing output voltage and output waveform pattern, which is constituted by an induction transformer 1 having the same output pulse width T for each processing step, as shown by arrows in the drawing. The pulse voltage of the output voltage of the induction transformer 1 is increased stepwise as the processing steps progress from 1 to n.

In the cathode ray tube 2 to be processed, the output voltage is changed from the anode terminal 6 of the induction transformer 1 to the anode terminal 5 of the cathode ray tube 2 shown in FIG. , A high-pressure treatment for sequentially applying the pressure was performed.

[0006]

By the way, the conventional high-voltage processing pattern shown in FIG. 4 does not provide sufficient withstand voltage characteristics, and is generally known to improve the withstand voltage characteristics. When the rise is performed, the discharge power of the high-pressure treatment generated between the electron gun electrodes of the cathode ray tube 2 becomes excessive, the discharge traces that damage the electron gun electrode surface increase, and conversely, the withstand voltage characteristic deteriorates. In some cases, discharge to the neck glass of the cathode ray tube 2 occurs, causing a problem that cracks occur in the neck glass.

For this reason, there is a drawback that the voltage can be applied only to an applied voltage which does not cause damage to the surface of the electrode of the electron gun of the cathode ray tube 2 or cracks in the neck glass.

An object of the present invention is to provide a high-pressure processing method which solves the above-mentioned problems and improves withstand voltage characteristics.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention comprises a step of processing a pulse width T of an output of an induction transformer of a plurality of power supplies for generating a high applied voltage used in a high voltage processing of a cathode ray tube. As the process progressed, the induction transformer was configured to be reduced step by step individually.

According to the present invention, the output pulse width T of the induction transformer for each processing step used in high-pressure processing composed of a plurality of processing steps is reduced stepwise individually as the processing steps progress. As a result, the power of the discharge of the high-pressure processing generated between the electrodes of the electron gun of the cathode ray tube acts to be suppressed as it approaches the final step. The discharge power becomes excessive, the discharge marks that damage the electrode surface of the electron gun increase, and consequently the withstand voltage characteristic deteriorates. The problem of doing so is also eliminated.

Therefore, the output voltage of the induction transformer in each processing step can be increased from the conventional voltage as the processing step progresses, so that the withstand voltage characteristic can be improved at the end of the final processing step.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an applied voltage connection showing a high-pressure processing method for a cathode ray tube according to an embodiment of the present invention. In FIG. All terminal conductive sockets to be connected (except anode), 5 is an anode terminal of the cathode ray tube 2, 7 is an induction transformer having a variable high voltage pulse width in each processing step,
Reference numeral 8 denotes a cathode terminal of the induction transformer electrically connected to the all-terminals conduction socket 3, and reference numeral 9 denotes an anode terminal of the induction transformer electrically connected to the anode terminal 5 of the cathode ray tube 2.

FIG. 2 shows patterns of output voltages and output waveforms of applied voltages showing a high voltage processing method for a cathode ray tube according to an embodiment of the present invention. The output pulse width T of the transformer 7 is configured to be smaller stepwise individually as the processing steps progress, and the output voltage of the induction transformer 7 is increased from the conventional voltage as approaching the final processing step.

In the cathode ray tube 2 to be processed, the output voltage of the induction transformer 7 is sequentially applied from the anode side terminal 9 of the induction transformer 7 to the anode terminal 5 of the cathode ray tube 2 in each of the processing steps shown in FIG. .

According to this embodiment, as the processing steps progress, the output voltage of the induction transformer 7 is raised above the conventional voltage, so that the withstand voltage characteristic can be improved with the same number of processing steps as in the prior art. The conventional problems of damage to the electrodes of the cathode ray tube electron gun and the neck glass were also eliminated.

In the above embodiment, the output pulse width T in the final processing step is 1/5 of the conventional one, and the output voltage can be increased by several KV to several tens of KV compared to the conventional one.

However, if the output pulse width T is too small, the discharge power between the electron gun electrodes is too suppressed,
Since sufficient high-pressure processing cannot be performed, the output pulse width T and the output voltage may be determined while observing the discharge trace on the surface of the electrode of the electron gun, the occurrence of cracks in the neck glass, and the withstand voltage characteristics.

In the above-described embodiment, the output pulse voltage of the induction transformer for each processing step is set to a positive voltage. However, this voltage is set to a negative voltage, and the anode terminal 9 of the induction transformer 7 shown in FIG. Is connected to the anode terminal 5 of the cathode ray tube 2, the anode terminal 9 is grounded, the ground of the cathode terminal 8 of the induction transformer 7 is disconnected, and the cathode terminal 8 is connected to the cathode terminal of the cathode ray tube 2. Even if a negative voltage is sequentially applied to all the terminal conduction sockets 3, the same effect as the above-described positive voltage application can be obtained.

[0019]

As described above, the high-voltage processing method for a cathode ray tube according to the present invention reduces the output pulse width of the induction transformer of a plurality of power supplies in a stepwise manner as the processing steps progress. Since the power of the discharge between the electrodes of the gun is suppressed, damage to the electron gun electrodes and neck glass, which has occurred in the past, can be eliminated. There is an effect that the withstand voltage characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an applied voltage connection showing a high-pressure processing method for a cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a diagram showing an output voltage of an applied voltage and a pattern of an output waveform showing a high-pressure processing method for a cathode ray tube according to an embodiment of the present invention;

FIG. 3 is a configuration diagram of an applied voltage connection for performing conventional high-pressure processing.

FIG. 4 is a diagram showing a conventional high-voltage processing output voltage and an output waveform pattern;

[Explanation of symbols]

 2 Cathode ray tube 3 All terminal conduction socket 5 Anode terminal of cathode ray tube 7 Induction transformer (power supply for high voltage processing) 8 Cathode side terminal of induction transformer 9 Anode side terminal of induction transformer T Output pulse width (high voltage pulse width)

Claims (6)

[Claims] In a high-pressure processing method for sequentially applying different applied voltages to an electron gun electrode of a cathode ray tube in a plurality of processing steps, the width of a high-voltage pulse to be applied is changed for each processing step. High pressure treatment method for cathode ray tubes. 2. A high-pressure processing method for a cathode ray tube according to claim 1, wherein said high-voltage pulse width is reduced in each processing step. 3. The high-pressure processing method according to claim 2, wherein a pulse voltage of said high-voltage pulse is increased in each processing step. 4. A high-pressure processing method for a cathode ray tube according to claim 1, wherein said high-voltage pulse is a positive voltage. 5. The method according to claim 1, wherein said high-voltage pulse is a negative voltage. 6. The method according to claim 1, wherein said high voltage pulse is generated by an induction transformer.