JPH0143423B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-electron gun electrode structure for a color cathode ray tube that generates a plurality of electron beams. The present invention relates to an electron gun electrode assembly with an integrated electrode forming an electron lens.

Simplify the assembly work of the electron gun electrode assembly, improve assembly accuracy, or reduce the volume occupied by the electron gun electrode assembly due to the reduction in the diameter of the neck of the glass envelope in which the electron gun of a color cathode ray tube is sealed. As a means of achieving this, an electron gun electrode structure is generally used which is electrically and structurally common and includes an integrated electrode for each electron beam path to form a substantially separate or common electron beam. Furthermore, as a means to significantly improve the focusing characteristics of the main electron lens of the electron gun for the electron beam, an electron gun electrode assembly is used which is equipped with a multi-stage focusing electron lens that combines multiple electron lenses instead of just one main electron lens. However, depending on the electrode configuration, there are some electrodes whose axial length is equal to or less than the gap between opposing electrodes, and the heat capacity of these electrodes is significantly smaller than that of other electrodes.

During operation of the electron gun, different high voltages are applied between the electrodes, creating a large potential difference between the opposing electrodes, so the voltage resistance characteristics between the electrodes must be good. Therefore, during the cathode ray tube manufacturing process, high voltage treatment is performed to improve the withstand voltage characteristics between the electrodes where the above-mentioned high potential difference occurs, but if there is a large difference in heat capacity between multiple electrodes, Sufficiently high voltage processing is not possible, and the withstand voltage characteristics between the electrodes deteriorate significantly.

Figures 1 to 3 show one of the conventionally used electron gun electrode structures equipped with multistage focusing electron lenses.
This will be explained according to the diagram. Figures 1 and 2 show a conventional in-line type in which cathodes are arranged on the same plane, electrically insulated from each other and spaced at equal distances, and the main electron lens is a bi-potential type with three main electron lenses.・A front view and a side view of the electron gun electrode structure 1 which adopts a multi-stage focusing electron lens system in which focus electron lenses are stacked, respectively, and FIG. 3 is A-A shown in FIG. 1.
A cross section is shown. The electron gun electrode assembly 1 includes cathode assemblies 10 which are insulated from each other and arranged in a line at equal intervals in the same plane, and electrically common cathode assemblies 10 which are arranged in sequence in the electron beam traveling direction in opposition to the cathode assemblies 10. The G1 electrode 11, which is a control electrode, and the G2 electrode 12, which is an acceleration electrode for the thermionic beam emitted from the cathode, are electrically and structurally common and form substantially independent electron lenses in each electron beam path. The G3 electrode 13 is a first focusing electrode, the G4 electrode 14 is a first anode electrode, and the second focusing electrode is an integrated electrode.
It is composed of a G5 electrode 15 and a G6 electrode 16 which is a second anode electrode. Each electrode has a supporter 18 (see FIG. 3) with a plurality of notches 18A at its tip to increase the strength of the fusion bond with the insulator support rod 19. By embedding it in the rectangular columnar insulator support rod 19 and fusing it, the distance between each electrode is maintained and fixed at a predetermined dimension. The G4 electrode 14 and the G6 electrode 16 are connected to have the same potential by a power supply line 17A, and an anode terminal (not shown) is provided in the funnel-shaped part of the cathode ray tube glass envelope in which the electron gun electrode structure 1 is sealed. A high anode voltage of about 20 to 30 KV is supplied from the internal conductive coating connected to the G3 electrode 13 and G5 electrode 15,
Although not shown, a focused voltage of about 20 to 40% of the anode voltage is supplied from the power supply pin of the stem on which the electron gun electrode assembly 1 is supported and fixed, and the other electrodes are also at the same potential from the power supply pin of the stem. They are mutually connected to the power supply pins of the stem so that a predetermined voltage is supplied. The electron beam emitted from the cathode 10 crosses the electron beam formed near the G1 electrode 11 and G2 electrode 12.
Divergent from the over point, G2 electrode 12 and G3 electrode 1
After pre-focusing with the pre-focus lens formed between G3 electrode 13 and G4 electrode 14, G4
Electrode 14 and G5 electrode 15, G5 electrode 15 and G6 electrode 1
The beam is sequentially focused in three stages by three independent bi-potential type lenses, each of which serves as the main focus lens, formed in the gap between the two electrodes, so that the beam spot has the smallest cross-sectional area on the fluorescent surface. The focusing voltages applied to the G3 electrode 13 and the G5 electrode 15, which are focusing electrodes, are adjusted. The electron beam prefocused by the prefocus lens is focused in three stages by three main focus lenses, so the main focus lens is different from the one main focus lens in the conventional electron gun.・The strength of each lens can be weaker than the other lenses. Therefore, the electron beam can be gradually focused by the three main lenses, and the spherical aberration of the main lens system becomes extremely small, and even when the beam current is large during cathode ray tube operation, the electron beam flux remains the same as that of each main electron lens. Since the beam passes through the center with small aberrations, a sharp beam bundle is obtained, and a high-resolution received image can be obtained on the fluorescent surface even on a high-brightness screen.

As described above, a high anode voltage is applied to the G4 electrode 14 and the G6 electrode 16, and a medium-high voltage of about 20 to 40% of the anode voltage is applied to the G3 electrode 13 and the G5 electrode 15 as a focusing voltage. That is, G3 electrode 13 to G6 electrode 16
A high voltage anode voltage and a medium-high voltage focusing voltage are periodically applied between the G3 electrode 13 and the G3 electrode 13.
G4 electrode 14, G4 electrode 14 and G5 electrode 15 and G5
Since a large potential difference is generated between the electrode 15 and the G6 electrode 16, the distance between the opposing electrodes and the distance between the supports embedded in the insulating support rod 19 greatly affect withstand voltage characteristics. G3 electrode 13 and G4 electrode 14, G4 electrode 14 and G5 electrode 15, and G5 electrode 1
The larger the distances a ₁ , a ₂ , and a ₃ between the electrodes 5 and 16, the better in terms of withstand voltage characteristics, but if they are too large, they will be affected by the penetration of an external electric field, and the electron beam path during the electron beam passage may become undesirable. Therefore, a size that is not affected by this and the same size is usually selected. In addition, the withstand voltage characteristics between the electrode supports 18 of the G3 electrode 13, G4 electrode 14, G5 electrode 15, and G6 electrode 16 depend on the specific resistance value due to the composition of the insulator support rod 19 and the surface resistance value due to the surface condition, etc. It is determined by the minute leakage current flowing through the
It is desirable that the distance between each electrode supporter 18 is as large as possible, but this is determined by the axial length of each electrode determined from the focus characteristics and the mutual electrode spacing a ₁ ,
Determined by a ₂ and a ₃ . On the other hand, depending on the electrode configuration determined by the focus characteristics, the axial length of a certain electrode may be significantly shorter than other electrodes, and in some cases, it may be equal to or less than the gap between opposing electrodes. , and the heat capacity of that electrode is extremely small compared to other electrodes. In the electron gun electrode structure shown in FIGS. 1 and 2, the G4 electrode 14 corresponds to this.

However, during the cathode ray tube manufacturing process, in order to improve the withstand voltage characteristics between the electrodes where the above-mentioned high potential difference occurs,
A high voltage several times higher than the anode rated voltage actually used is applied to the G6 electrode 16 and G4 electrode 14, which are the anode electrodes, and other electrodes, that is, the focusing electrodes.
G5 electrode 15, G3 electrode 13 and G2 electrode 12, G1
There is a high voltage treatment process in which the electrode 11 and the cathode 10 are set at a ground potential to remove minute protrusions, dirt, etc. from the electrode surface. The main electron lens electrode mutual spacing a ₁ , a ₂ , a ₃ is usually about 0.8 ~ 1.5 mm, and the high voltage processing voltage is 80 ~
As a result, a strong electric field of 100 to 50 MV/m is applied between the main electron lens electrodes, and due to the so-called cold cathode emission effect, the high potential electrodes G6 electrode 16 and G4 electrode 14 are grounded. A cold cathode emission current flows toward the G5 electrode 15 and the G3 electrode 13, which are at potential. In other words, arrow B in Figure 2
As shown in G5, the cold cathode emitted electrons are at ground potential.
The electrons flow from the electrode 15 and the G3 electrode 13 to the G6 electrode 16 and the G4 electrode 14, which are at high potential.
6. The electrons collide with the surface of the electrode opposite to the electrode at ground potential of the G4 electrode 14, and the kinetic energy of the electrons is converted into heat, which continues to heat the electrode during high voltage processing, causing the G6 electrode 16 and the G4 electrode 14 to The electrode surface temperature rises rapidly. In particular, as shown by arrow B in Figure 2, during the high voltage treatment process, the G4 electrode 14 sandwiched between the ground potential electrodes is heated by the electrons emitted from the G5 electrode 15 and the G3 electrode 13, and both sides are heated. Therefore, 2 from the G6 electrode 16, which is heated only on one side.
It is heated twice as much. Furthermore, the axial length of the electrode, determined from the design dimensions of the main electron lens electrode configuration, is significantly shorter than other electrodes and the electrode spacing, as shown in Figure 2.
Since the G4 electrode 14 has a significantly smaller heat capacity than other electrodes, it is heated until it becomes red hot by the colliding electrons, and its electrode support part 18 is also red hot, and the local heat locally damages the insulator support rod 19. distort,
As a result, cracks are formed or even broken, resulting in mechanical and electrical failure of the electron gun electrode assembly 1. Therefore, the conditions for high voltage treatment are G3 electrode 13 facing G4 electrode 14 and G5 electrode 1.
As a result, the withstand voltage quality was insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron gun electrode structure that eliminates the above-mentioned drawbacks and allows good voltage resistance between the electrodes.

The present invention provides a cathode ray tube electron gun electrode structure in which an anode electrode to which a high voltage anode voltage is applied and a focusing electrode to which a focusing voltage lower than the anode voltage is arranged alternately to form a main focusing electron lens. In this case, the distance between opposing surfaces of the anode electrode and the focusing electrode in which opposing focusing electrodes are arranged on both sides is set to be larger than the distance between the opposing surfaces of the anode electrode and the focusing electrode in which opposing focusing electrodes are arranged only on one side. It is characterized by being

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 4 is a side view of the electron gun electrode structure showing the present invention, and for the sake of simplicity, the first to
Components that are the same as those in the conventional example shown in FIG. 3 are given the same reference numerals.

The electron gun electrode assembly 2 includes cathode assemblies 10 which are insulated from each other and arranged in a line at equal distances in the same plane, and electrically common cathode assemblies 10 which are arranged in sequence in the electron beam traveling direction in opposition to the cathode assemblies 10. G1, the control electrode
The electrode 11 and the G2 electrode 12, which is an accelerating electrode for the thermionic beam emitted from the cathode, are electrically and structurally common, and each electron beam path is composed of an integrated electrode that forms a substantially independent electron lens. G3 electrode 23 is the first focusing electrode, and the first anode electrode
G4 electrode 24, G5 electrode 25 which is a second focusing electrode,
It is constructed in the same manner as the conventional one with a G6 electrode 26 which is a second anode electrode. Each electrode has a supporter 18 in which a part embedded in the insulator support rod 19 is formed, and the buried part of each supporter 18 is embedded in two insulator support rods 19 and fused, so that each electrode is spaced apart. is held and fixed at a predetermined size. As before, with G4 electrode 24
Although not shown, the G6 electrode 26 is made to have the same potential through a power supply line, and is supplied with a high anode voltage of about 20 to 30 KV. A focusing voltage of ~40% is provided.

However, G3 electrode 23, G4 electrode 24, G5 electrode 25
The total axial length and electrode structure of the G6 electrode 26 are completely the same as before, but the G3 electrode 23 and the G4 electrode 2
4. G4 electrode 24, G5 electrode 25, and G5 electrode 25
The distance between each electrode of the G6 electrode 26 is b ₁ , b ₂ , b _{3 ,} respectively.
If the electrode spacing of the corresponding conventional electron gun electrode assembly 1 is a ₁ = a ₂ = a ₃ = a, then the electrode spacing is set so that b ₁ = b ₂ a, b ₃ < b ₂ = b ₁ . It is set.

That is, the electrode spacing b ₁ , b 2 facing the G3 electrode 23, which is set to the ground potential during high voltage processing, and the G4 electrode 24, which is a high potential electrode that is sandwiched from both sides by the G5 electrode _25.
is equal to or larger than the corresponding conventional electrode spacing, and the electrode spacing b ₃ between the G5 electrode 25, which is at ground potential, and the G6 electrode 26, which is a high potential electrode facing only one side, is the electrode spacing b ₁ , b Set smaller than ₂ .
However, if the inter-electrode spacings b ₁ and b ₂ are too large, they will be affected by the penetration of external electric fields and undesirably bend the electron beam path in the electron beam passage hole, so they should be selected to a size that will not be affected by this. , _b3 deteriorates the withstand voltage characteristics between the electrodes if they are too small, so they are selected to a size that does not cause this deterioration.

As described above, according to the embodiment of the present invention, the G4 electrode 24, which is held at a high potential and is sandwiched from both sides by the two electrodes, the G3 electrode 23 and the G5 electrode 25, which are held at the ground potential during high voltage processing, is placed at the opposite side. The electrode spacing b ₁ , b ₂ is the opposing electrode spacing between the G5 electrode 25, which is set to ground potential, and the G6 electrode 26, which is set to high potential and faces only on one side.
b Since it is set larger than ₃ , the G3 electrode 23
The electric field strength between the G4 electrode 24 and the G5 electrode 25 can be made weaker than the electric field strength between the G5 electrode 25 and the G6 electrode 26. Therefore, the G4 electrode 24 to the G3 electrode 23 due to the cold cathode emission effect due to the strong electric field,
The cold cathode emission current flowing into the G5 electrode 25 is smaller than that flowing into the G5 electrode 25 from the G6 electrode 26.
That is, the amount and kinetic energy of electrons emitted from the G3 electrode 23 and G5 electrode 25 and colliding with the surface of the G4 electrode 24 are smaller than the amount and kinetic energy of electrons emitted from the G5 electrode 25 and colliding with the surface of the G6 electrode 26. Therefore, the heat capacity of G4 electrode 24 is G6
Even if it is significantly smaller than the electrode 26, the G4 electrode 24 will not be heated abnormally by increasing the high voltage processing voltage, and therefore the high voltage processing conditions can be matched among all electrodes. The withstand voltage quality becomes uniform, and since the high voltage processing voltage can be further increased, the withstand voltage characteristics between the electrodes are significantly improved.

In the above explanation, an electron gun electrode structure consisting of four main electron lens electrodes has been described. It goes without saying that the present application can also be applied to gun electrode structures.

Further, in the above description, an in-line type electron gun electrode structure including an integrated electrode has been described, but it goes without saying that the present application can also be applied to a delta type electron gun or a single electron gun electrode structure.

[Brief explanation of drawings]

1 and 2 are a front view and a side view, respectively, of an in-line electron gun electrode structure equipped with a conventional multi-stage focusing electron lens, and FIG. The figure shows a side view of an in-line electron gun electrode structure equipped with a multi-stage focusing electron lens, showing one embodiment of the present invention. 10... Cathode structure, 11... G1 electrode, 12...
...G2 electrode, 13 _-1 , 13 _-2 , 23 _-1 , 23 _-2 ...
G3 electrode, 14 _-1 , 14 _-2 , 24...G4 electrode, 1
5 _-1 , 15 _-2 , 25...G5 electrode, 16, 26...
...G6 electrode, 18... electrode supporter, 19... insulator support rod.

Claims (1)

[Claims] 1 an anode electrode to which a high anode voltage is applied;
In a cathode ray tube electron gun electrode structure in which a main focusing electron lens is formed by alternately arranging focusing electrodes to which a focusing voltage lower than an anode voltage is applied, an anode electrode and a focusing electrode with opposing focusing electrodes arranged on both sides. A cathode ray tube electron gun electrode assembly characterized in that a distance between mutually facing surfaces of the anode electrode and a focusing electrode is set to be larger than a distance between mutually facing surfaces of an anode electrode and a focusing electrode in which a facing focusing electrode is arranged only on one side.