JP3584763B2 - Electron gun assembly for cathode ray tube - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electron gun structure for a cathode ray tube, and more particularly to a structure for supporting electrodes on an insulating support.
[0002]
[Prior art]
FIG. 8 shows an electron gun assembly used in a conventional projection type cathode ray tube. The electron gun assembly 1 includes a cathode 3 which receives heat from a heater 2 and emits thermoelectrons, a G1 electrode 4 which is a control electrode, a G2 electrode 5 which is an acceleration electrode, a G3 electrode 6 which is a first focusing electrode, and a second focusing electrode. A G4 electrode 7 as a focusing electrode and a G5 electrode 8 as an anode electrode are sequentially arranged, and a part of each electrode is embedded and fixed in two insulating supports 9 (multiform rods), respectively. It is mounted in the neck (not shown) of the tube. Each electrode is supplied with power from the stem lead 11 and controls, accelerates and focuses the electron beam by the action of an electric field formed by the cathode 3 to the G5 electrode 8 to reach the phosphor screen surface (not shown) of the cathode ray tube. Let it.
[0003]
FIG. 9 shows the G1 electrode 4 and the electrode support 12 in an enlarged manner. The electrode support 12 has a U-shaped cross-section or a structure in which two flat plates are opposed to each other and fixed by welding. The electrode support 12 is fixed to the insulating support 9 by two plates. A portion 14, a stem lead connection portion 15 extending from each of the two plates in the direction of the stem lead 11, and a bridge portion 16 connecting the two plates on the G1 electrode 4 side and fixing the two plates to the G1 electrode 4.
[0004]
[Problems to be solved by the invention]
In such a structure, the welding positions of the two electrode supports 12 disposed on both sides of the G1 electrode 4 are easily shifted from each other, and it is not easy to assemble with high accuracy. In addition, when the cathode ray tube is operated, the temperature of the G1 electrode 4 rises to about 200 ° C., so that the G1 electrode 4 is easily deformed by heat, and the performance as an electron gun is reduced. Further, there is a problem that an electric field is concentrated on an edge portion of the insulating support fixing portion 14 of the electrode support 12 on the phosphor screen surface side, so that discharge is likely to occur.
[0005]
SUMMARY OF THE INVENTION The present invention solves such a problem, and can easily and accurately assemble an electrode support and a G1 electrode. It is an object of the present invention to provide an electron gun assembly for a cathode ray tube which can prevent the electric field concentration.
[0006]
[Means for Solving the Problems]
The electron gun assembly for a cathode ray tube according to the present invention is an electron gun assembly for a cathode ray tube in which an electrode having a cylindrical portion is fixed to a plurality of insulating supports arranged around the electrode by a plurality of electrode supports, An electrode support is fixed to a ring member mounted around the electrode, and the electrode support includes an insulating support fixing portion including two plates fixed to the insulating support, and an insulating support fixing portion. A stem lead connecting portion extending from the portion in the stem lead direction, and a bridge portion connecting the insulating support fixing portion from the vicinity of the cylindrical portion on the phosphor screen surface side to the end on the insulating support side, The connecting portion between the insulating support fixing portion and the bridge portion is formed with a smooth curved surface, and the insulating supporting member fixing portion and the bridge portion are formed as a whole of the end on the insulating support side. Over it, characterized in that it is buried in the insulating support body (claim 1). According to this configuration, since the plurality of electrode supports can be fixed to the ring member in advance and attached to the electrodes, it is possible to prevent a displacement of the fixed position of the electrode supports, and to separate the electrodes and the insulating support. It can be assembled with high accuracy. Further, since the ring member reinforces the electrode, thermal deformation of the electrode during operation of the cathode ray tube can be reduced.
[0007]
Also, the edge of the insulating support fixing portion on the phosphor screen surface side can be eliminated, and the flat bridge portion faces the electrode on the high voltage side, so that the electric field concentration near the electrode support and the electrode support and the high voltage It is possible to prevent dielectric breakdown between the electrodes on the side. Further, by forming the connecting portion between the insulating support fixing portion and the bridge portion with a smooth curved surface, electric field concentration and dielectric breakdown can be more reliably prevented. Furthermore, since the entire edge of the insulating support fixing portion and the end of the bridge portion on the insulating support side is buried in the insulating support and is not exposed, the electric field concentration near the electrode support and the electrode support and the high voltage side Dielectric breakdown between the electrodes can be more effectively prevented.
[0008]
The electrode support according to claim 1 , wherein the electrode support is formed by integrally forming the insulating support fixing portion, the bridge portion, and the stem lead connecting portion by bending a plate-like body. there is preferably (claim 2). With this configuration, the connecting portion between the insulating support fixing portion and the bridge portion can be formed with a smooth curved surface, and the electric field concentration and the dielectric breakdown can be more reliably prevented. Further, the manufacture of the electrode support is easy.
[0009]
In the second aspect , it is preferable that the electrode support and the ring member are integrally formed from a single plate by drawing and bending (claim 3 ). With this configuration, the electrode support can be firmly fixed to the electrode via the ring member.
[0010]
Further, in any one of claims 1 to 3 , it is preferable that the electrode is a control electrode (G1 electrode) (claim 4 ). With this configuration, a predetermined voltage can be applied to the G1 electrode from the stem lead via the electrode support.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an enlarged view of the vicinity of the G1 electrode 4 in the cathode ray tube electron gun structure of the present invention. The electron gun assembly 1 has a cup-shaped G1 electrode 4 fixed to two insulating supports 9 arranged around the G1 electrode 4 by two electrode supports 12. A perforated ring member 13 is welded around the G1 electrode 4, and the electrode support 12 is welded to the ring member 13.
[0012]
2 to 4 show how the electrode support 12 is fixed to the G1 electrode 4 in an enlarged manner from three directions. The electrode support 12 includes an insulating support fixing portion 14 composed of two plates fixed to the insulating support 9 (shown by broken lines), and a stem lead (not shown) from the two insulating supporting fixing portions 14. ), And a bridge portion 16 which connects the two insulating support fixing portions 14 on the phosphor screen surface side and is fixed to the insulating support 9. The electrode support 12 is attached to the G1 electrode 4 after being fixed in a predetermined position of the ring member 13 in advance. For this reason, it is possible to prevent the displacement of the fixed position of the electrode support 12 with respect to the G1 electrode 4, and it is possible to assemble the G1 electrode 4 and the insulating support 9 with high accuracy. Further, since the entire inner surface of the ring member 13 is in contact with the outer peripheral surface of the G1 electrode 4, the electrode support 12 is firmly fixed to the G1 electrode 4.
[0013]
The electrode support 12 and the ring member 13 of the present embodiment are formed integrally from one plate by drawing and bending. In the electrode support 12, the insulating support fixing portion 14, the bridge portion 16, and the stem lead connecting portion 15 are integrally formed by bending. For this reason, the connecting portion between the insulating support fixing portion 14 and the bridge portion 16 is formed with a smooth curved surface, and the edge portion of the insulating support fixing portion 14 is not exposed on the phosphor screen surface side, so that the flat surface is formed. Since the bridge portion 16 faces the G2 electrode 5, electric field concentration near the electrode support 12 and dielectric breakdown between the electrode support 12, the G2 electrode 5, and the like can be prevented.
[0014]
Notches are provided in the insulating support fixing portion 14 and the bridge portion 16 of the electrode support 12, respectively, so that the fixing to the insulating support 9 is firm. In addition, the stem lead connection portion 15 is widened on the distal end side to facilitate connection with the stem lead.
[0015]
Next, an experimental example in which the present invention is applied to a projection type cathode ray tube and its effect is confirmed will be described. FIG. 5 shows the coaxiality of the G1 electrode and the G2 electrode in comparison with the conventional example (FIGS. 8 and 9) and the present invention. Here, the coaxiality between the G1 electrode and the G2 electrode means a distance (deviation) between the center of the electron beam passage hole of the G1 electrode and the center of the corresponding electron beam passage hole of the G2 electrode. As shown in FIG. 5, in the conventional example, the G1-G2 coaxiality is 10.96 [μm] on average, and the variation is σ = 4.01 [μm], whereas in the present invention, the average coaxiality is 8. 11 [μm] and the variation σ = 2.83 [μm]. This is because the assembling accuracy of the G1 electrode and the electrode support is improved.
[0016]
FIG. 6 shows the roundness of the electron beam spot on the phosphor screen in comparison with the conventional example and the present invention. Here, the circularity refers to the ratio between the maximum diameter and the minimum diameter of the electron beam spot at the center of the phosphor screen surface, and indicates a perfect circle at 100%. As shown in FIG. 6, in the conventional example, the average of the circularity is 76.5 [%], and the variation is σ = 10.8 [%], whereas in the present invention, the average of the circularity is 86. 0% and the variation are improved to σ = 7.2%, respectively. This is because, in addition to the improvement in the assembly accuracy of the G1 electrode and the electrode support, the strength of the fixing between the electrode support and the G1 electrode is improved, and the thermal deformation during operation of the electron gun is reduced.
[0017]
FIG. 7 shows the coaxiality of the core and the haze of the electron beam spot on the phosphor screen surface in comparison between the conventional example and the present invention. Here, the coaxiality between the core and the haze means the distance (deviation) between the virtual center of the core and the virtual center of the haze. As shown in FIG. 7, in the conventional example, the average of the coaxiality is 0.175 [mm] and the variation is σ = 0.044 [mm], whereas in the present invention, the average of the coaxiality is 0.114 [mm]. mm], and the variation is improved to σ = 0.040 [mm]. This is because the assembling accuracy of the G1 electrode and the electrode support is improved.
[0018]
Although the example in which the present invention is applied to the projection type cathode ray tube has been described above, the present invention is also applicable to a cathode ray tube such as a color cathode ray tube. Further, the present invention can be applied to holding other than the G1 electrode.
[0019]
【The invention's effect】
As described above, the present invention can easily and accurately assemble the electrode support and the G1 electrode, and can prevent deformation of the G1 electrode due to heat during operation of the cathode ray tube and concentration of an electric field on the electrode support. An object of the present invention is to provide an electron gun assembly for a cathode ray tube.
[Brief description of the drawings]
FIG. 1 is an enlarged view of a main part of an electron gun structure of the present invention. FIG. 2 is a front view of an electrode support and a G1 electrode according to the present invention. FIG. 3 is a plan view of the electrode support and a G1 electrode. FIG. FIG. 5 is a diagram showing a comparison of G1-G2 coaxiality between a conventional example and the present invention. FIG. 6 is a diagram showing a comparison between a conventional example and the present invention in terms of roundness of a beam spot. FIG. 7 is a diagram showing a comparison between core-haze coaxiality of a conventional example and the present invention. FIG. 8 is a diagram showing a conventional electron gun assembly. FIG. 9 is a front view of a conventional electrode support and a G1 electrode. [Explanation of symbols]
REFERENCE SIGNS LIST 1 electron gun assembly 4 G1 electrode 9 insulating support 10 stem 11 stem lead 12 electrode support 13 ring member 14 insulating support fixing part 15 stem lead connecting part 16 bridge part

Claims (4)

An electrode having a tubular portion is an electron gun assembly for a cathode ray tube fixed by a plurality of electrode supports to insulating supports arranged in plural around the electrodes, wherein the electrode supports are mounted around the electrodes. is fixed to the ring member,
The electrode support includes an insulating support fixing portion formed of two plates fixed to the insulating support, a stem lead connecting portion extending from the insulating supporting fixing portion in a stem lead direction, and the insulating support fixing. A bridge portion connecting the portion from the vicinity of the tubular portion on the phosphor screen surface side to the end on the insulating support side,
A connection portion between the insulating support fixing portion and the bridge portion is formed with a smooth curved surface,
An electron gun assembly for a cathode ray tube , wherein the insulating support fixing portion and the bridge portion are buried in the insulating support over the entire end on the insulating support side . 2. The electron gun for a cathode ray tube according to claim 1 , wherein the electrode support is formed by integrally forming the insulating support fixing portion, the bridge portion, and the stem lead connecting portion by bending a plate-like body. Structure. The electron gun assembly for a cathode ray tube according to claim 2 , wherein the electrode support and the ring member are integrally formed from a single plate by drawing and bending. The electron gun assembly for a cathode ray tube according to any one of claims 1 to 3 , wherein the electrode is a control electrode (G1 electrode).

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