JPS59148245A - Electron gun electrode structure - Google Patents

Abstract

PURPOSE:To increase voltage for voltage resistance treatment during manufacture of a cathode- ray tube without breaking an insulating supporter rod so as to improve the voltage resistance of an electron gun electrode structure by burying a shorter part of the supporter of a specified electrode in the insulating supporter rod by adjusting the entire length of the supporter to be smaller than the entire length of the supporters of other electrodes. CONSTITUTION:An electron gun electrode structure 2 is constituted by burying the supporters of three cathode structure 10 insulatedly arranged on the same plane in a line at equal distances and a G1 electrode 11 - a G3 electrode 13, a G4 electrode 24, a G5 electrode 15 and a G6 electrode 16 which are arranged facing the cathode structures 10 in the traveling direction of an electron beam in that order in an insulating supporter rod 19 to maintain the distances between these electrodes at given dimensions. The entire length of the supporters 28 of the G1 electrode 11 - the G6 electrode 16 excepting the G4 electrode 24 are adjusted to (d0) which is the same as the conventional length, while that of the G4 electrode 24 is adjusted to (d1) which is smaller than (d0). By the means mentioned above, the distance (d) between the end of the supporter 28 of the G4 electrode 24 and the back surface of the insulating supporter rod 19 can be made larger than the distance (a) between the supporter 18 of the other electrodes and the back surface of the insulating supporter rod 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron gun electrode structure VC with improved withstand voltage characteristics of a multi-gun electrode structure of a color cathode ray tube that generates a plurality of electron beams.

Among the performances required of recent color cathode ray tubes, improvements in screen brightness and resolution are particularly required. In order to improve the screen brightness, improvements were made to the luminous efficiency of the phosphor and the phosphor surface emitting mechanism, and to improve the resolution, a multi-stage focusing electron gun was introduced, and the phosphor surface voltage, that is, the electron The anode voltage of guns is being increased to a higher voltage. Therefore, due to the increase in the number of electrode elements that produce a high potential difference due to the multistage focused electron gun, and the increase in the anode voltage, the withstand voltage characteristics of the electron gun electrode structure are damaged due to discharge of the receiver circuit in which the color cathode ray tube is mounted. This is extremely important to increase the reliability of prevention.

1 to 3 are front views of an example of a conventional multi-stage focusing electron gun electrode assembly 1 for the above purpose.

A side view and a cross section taken along lines A and -A in FIG. 1 are shown.

The electron gun electrode assembly 1 includes three cathode assemblies 10 which are insulated from each other and arranged in a line at an equal distance of 8i in the same plane, and an electric cathode assembly 10 which is arranged in sequence in the electron beam traveling direction in opposition to the cathode assemblies 10. G1 electrode 11, which is a structurally common control electrode.
02 is an accelerating electrode for the thermionic beam emitted from the cathode.
Electrode 12. Each electron beam path is composed of G3 electrodes 13 to G6 electrodes 16, which are electrically and structurally common and are integrated electrodes that form substantially independent electron lenses.

Each electrode has supports 18 provided at all tips of a plurality of notches 18A in order to increase the strength of the pivoting with the insulator support punch 19,
Two insulator support rods 1 are installed in the notch 18A' of the supporter 18.
Each electrode interval is maintained and fixed at a predetermined dimension by the VC, and the length of the supporter 18 is equal to the center line connecting the three in-line arrays, and the G1 electrodes 11 to G6 The entire length up to the electrode 16 has the same size do. G4 electrode 14 and G6 electrode 16 are connected to feeder line 17
Although not shown, the electron gun electrode A is connected to the anode terminal arranged in the funnel-shaped part of the cathode ray tube glass envelope in which the four bodies 1 are sealed. A high anode voltage of about 20 to 30 KV is supplied from the coating, and the same potential is applied from the G3 electrode 13 and the G5 electrode 15U power supply line 17BVC, and from the power supply pin of the stem on which the electron gun electrode assembly 1 is supported and fixed (not shown). 20-4 of anode voltage
A focused voltage of about 0% is supplied, and the other electrodes are also connected to the power supply pin of the stem so that a predetermined voltage is supplied from the power supply pin of the stem. Each of the three electron beams emitted from the cathode 10.1 is diverged from a crossover point formed near the G1 electrode 11 and G2 electrode 12, and is emitted from the cross-over point formed between the G2 electrode 12 and G3 electrode 13. - After being prefocused by the focus lens, the G3 electrode 13 and the G4 electrode 14. G4 electrode 14 and G5 electrode 15. G5 electrode 15 and G
A main focus lens formed between each of the six electrodes 16 sequentially focuses the light into three stages. In this way, in the multi-stage focusing electron gun electrode structure 1, the three main electron lenses can gradually focus the entire electron beam, and the resolution characteristics of the electron lenses are significantly improved. High-resolution images can be obtained even when there are many images.

On the other hand, when the color cathode ray tube is in operation, a high anode voltage is applied to the G4 electrode 14 and the G6 electrode 16, a medium-high voltage of 20 to 40% of the anode voltage is applied to the G3 electrode 13 and the G5 electrode 15, and each opposing electrode Since a large potential difference occurs between the electrodes, the withstand voltage characteristics between the electrodes must be good. For this reason, during the manufacturing process of color cathode ray tubes, in order to improve the withstand voltage characteristics between the electrodes where the above-mentioned high potential difference occurs, a high voltage equivalent to several times the rated voltage of the anode actually used - e.g.
A withstand voltage treatment is performed in which a voltage of 0 to 70 KV is applied between the electrodes to completely generate a discharge within the tube to remove minute protrusions on the surface of the electrodes and electrically clean them. In this treatment step, the G4 electrode 14 is at an anode potential depending on the specific resistance value determined by the composition of the insulator support rod 19 supporting the electrode, the surface resistance value determined by the dielectric constant, surface condition, etc. From the G6 electrode 16 to the G3 electrode 13 at low voltage (ground potential during the withstand voltage treatment process). A minute leakage current IL flows into the G5 electrode 15 side. When this current value exceeds the prestige level, the G4 electrode 14 is at an anode potential.
Dielectric breakdown occurs between the tip of the electrode supporter 18 embedded in the insulator support rod 19 at the G6 potential 16 and the opposing back surface 19A of the insulator support rod 19. In particular, dielectric breakdown is likely to occur in the G4 electrode 14, which is sandwiched between the G3 electrode 13 and the G5 electrode 15, which are low potential electrodes (ground potential during the withstand voltage treatment process), and at this time, the tip of the supporter 18 through which leakage current flows , a penetrating rack is generated in the insulator support rod 19 along the path 5- between the back surface 19A of the insulator support rod 19 facing this, and as this progresses, the insulator support rod 19 is destroyed and the electron gun electrode structure 1 It even leads to the destruction of VC.

Therefore, the withstand voltage processing voltage must be limited to a voltage that does not cause penetrating racks of the insulator support rods 19.
The voltage resistance between the electrodes is insufficient, and the quality of the voltage resistance between the electrodes is low. When using a normal cathode ray tube, discharge noise is generated between the electrodes, and the large discharge current that flows at this time causes the cathode ray tube drive circuit to The present invention has been made in view of the above-mentioned drawbacks of the conventional technology, and uses an electrode that can be applied with a voltage lower than the potential of the anode constituting the main electron lens. In an electrode to which the entire anode voltage, which is a high voltage, is applied from both sides, the total length of the supporter embedded in the insulator support rod is set shorter than the total length of the supporter of the electrode, so that the insulator support An electron gun electrode structure is provided in which the embedding depth of the support in the rod is shallow, and the withstand voltage processing voltage during the cathode ray tube manufacturing process can be increased without completely destroying the insulator support rod, and the withstand voltage quality is completely satisfactory. The entire purpose is to provide.

Embodiments of the present invention will be described in detail below with reference to the drawings. In order to simplify the explanation, the same reference numerals are given to the same parts as above.

FIG. 4 shows a complete side view of an in-line electron gun electrode structure 2 showing an embodiment of the present invention. The electron gun electrode assembly 2 includes three cathode assemblies 1o, which are insulated from each other and arranged in a line at equal distances S, in the same plane, and a G1 electrode which is arranged in sequence in the electron beam traveling direction in opposition to the cathode assemblies 1o. 11-G3 electrode 13
．． The G4 electrode 24°, the G5 electrode 15, and the 06 electrode 16 are configured such that each electrode supporter is embedded in an insulator support rod 19 to maintain a predetermined distance between each electrode.

The electron gun electrode structure 2 includes all G4 electrodes 24 () and 11 electrodes.
~ Supporter 18 for the insulator support rod 19 of the G6 electrode 16
d, the total length of which is the same as before. So, that of G4 electrode 24 is d
The configuration is exactly the same as the conventional electron gun electrode assembly 1 except that dl is smaller than o, and the G4 electrode 24 and the G6 electrode 16 are connected to a high anode voltage at the same potential by a feeder line (not shown). G3 electrode 13 and G5 electrode 15 are power supply line 1
7B applies a focusing voltage of about 20 to 40% of the anode voltage.

Since the total length d1 of the supporter 28 of the G4 electrode 24 is smaller than the total length do of the other electrode supports, its tip and the back open circuit Mb of the insulator support rod 19 are connected to the supporter 18 of the other electrode and the insulator support rod. It can be made larger than the back-to-back distance a of No. 19.

Therefore, in the withstand voltage treatment during the color cathode ray tube manufacturing process, the insulator support rod 1 of the G4 electrode 24, which is sandwiched between the G3 electrode 13 and the G5 electrode 15, which is at a low potential (ground potential during the withstand voltage treatment).
Since the dielectric breakdown voltage for G6 electrode 16 and G5 electrode 15.9 is dramatically higher than before, the withstand voltage processing voltage can be increased more than before. G5 electrode 1
5 and G4 electrode 24. The voltage resistance treatment to completely remove minute protrusions and dirt from the surfaces of the opposing electrodes of the G4 electrode 24 and the G3 electrode 13 and to electrically clean them is performed on the insulating support rod 19 in the part where the supporter of the G4 electrode 24 is buried. This can be done satisfactorily without being limited by dielectric breakdown voltage.

As a result, the withstand voltage quality between the electrodes can be significantly improved, and discharge noise will not be generated between the electrodes when the cathode ray tube is used, and the discharge current will not damage the drive circuit of the cathode ray tube or the peripheral circuit elements of the attached layer. Totally preventable.

On the other hand, a multi-stage focusing main electron gun electron gun electrode structure 2
Now, the total length d1 of the supporter 28 of the G4 electrode 24 is made shorter than the total length do of the supporter 18 of the other electrode.

The buried depth of the supporter 28 for the two insulator support rods 19Vc is shallower than the others, but the width of the supporter for the 05 electrode 15 and G3 electrode 13, which are located on both sides VC with the G4 electrode 24 in between, is the same as the conventional supporter width. This is because the buried depth for the insulator support rod 19 is the same as the conventional one, and it has sufficient support strength for the insulator support rod 19.

Even if the supporter 28 of the G4 electrode 24 is buried at a shallow depth with respect to the insulator support rod 19, its supporting strength can be maintained at the same level as the conventional one.

In the above explanation, the present invention is applied to the 04 electrode of a multi-stage focusing electron lens in which a medium-high voltage and a high voltage are applied to the four electrodes G3 electrode to G6 electrode throughout the period as the main electron lens. It goes without saying that the present invention is not limited to this method and can be applied to other potential distribution methods and multi-stage focusing electron lenses of four or more stages.

[Brief explanation of the drawing]

FIGS. 1 to 3 are front views of a conventionally used electron gun electrode assembly in which a multistage focusing electron lens is biased toward gold. A sectional view taken along line A-A' in the side view and front view, and FIG. 10... Cathode structure, 11... G1 electrode, 12... G2 electrode, 13-16...
G3 to G6 electrodes, 24...G4 electrode according to an embodiment of the present invention, 18.28... Electrode supporter, 1
9... Insulator support rod. 10- 1'8A Figure 3 Figure 4

Claims (1)

[Claims] In the electrodes to which the anode voltage is applied, which are sandwiched from both sides by electrodes to which the potential is lower than the high voltage anode voltage that constitutes the entire main electron lens, the entire length of the support element embedded in the insulator support rod is the electrode. An electron gun electrode assembly characterized in that the length is set shorter than the total length of the supporter.