JPH0628139B2 - Electron gun device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electron gun apparatus suitable for use in an electron gun for a shadow mask type color picture tube that emits a plurality of electron beams.

[Background of the Invention]

The shadow mask type color picture tube irradiates the fluorescent screen with three electron beams emitted and converged by the electron gun mounted in the neck through the shadow mask.
It is designed to reproduce color images by emitting color fluorescent materials. In general, as such an electron gun, one in which thermoelectrons emitted from a cathode are accelerated as an electron beam and focused on a fluorescent screen by a main electron lens using an electrostatic lens is widely used. There is.

FIG. 1 is a structural diagram of an ordinary shade mask type color picture tube. 1 is a phosphor screen in which phosphors emitting red, green, and blue colors are regularly formed in a dot shape or stripe shape on the inner surface of the panel 2, and 3 is adhered to the panel 2 via a fritted glass. A funnel, 4 is a net, and 6 is a stem in which a stem pin 5 is implanted, and these form a high vacuum envelope. Reference numeral 8 is an electron gun mounted in the neck 4, 9 is a shed mask placed in front of the phosphor screen 1, and the three electron beams 7 emitted from the electron gun 8 pass through the shed mask 9 and the fluorescent body. Hit the screen. Reference numeral 10 is a deflecting device for scanning an electron beam mounted on the outside of the envelope from the funnel 3 to the neck 4.

FIG. 2 shows a structure of a conventional electron gun device, (A) is a front view and (B) is a side view. Reference numeral 12 is a cathode that emits an electron beam, and 13 is a first electrode that controls the emitted electron beam.
The grid, 14 is the second grid for accelerating the electron beam,
Reference numerals 15, 16, 17, and 18 denote third, fourth, fifth, and sixth grids, respectively, which constitute the main electron lens, and 19 denotes an electrode support made of glass or the like for supporting the above electrodes. The third grid 15, the fifth grid 17, and the sixth grid 18 are each composed of two container-shaped members 15a, 15b, 17a, 17b, 18a, 18b. In addition, the container-shaped member 15 of the third grid 15
A has circular holes 20 formed on both sides.

Such a container-shaped member that constitutes the main electron lens electrode is generally formed by press working, and the opening surfaces having the respective flanges are opposed to each other, and the opposing surfaces of the flange are welded at a plurality of places to be integrated. To form a single grid electrode.

Next, a method of assembling such an electrode will be described with reference to FIG. Although the procedure for assembling the third grid 15 will be described here, the same applies to the fifth grid 17 and the sixth grid 18. In the figure, (A) is a cross-sectional view of the container-shaped members 15a, 15b, (B) is a front view of the assembly jig, and (C) is a cross-sectional view of the third grid after assembly.

First, the three cylindrical beam passage openings _15b1 are fitted into the thick base portion of the cored bar 22 of the assembly jig 21 to set the container-shaped member 15b. Next, the three circular beam passage holes _15a1 are fitted into the thin tip of the cored bar 22, and the container-shaped member 15a is set thereon. Then, the pressure jig 23 is set on the pressure jig 23, and a predetermined pressure is applied to the pressure jig 23 via an elastic body to fix it.
A flange portion 15 _a2 of the container-like member 15a and 15b are opposed to
Weld 15 _b2 in several places.

However, the container-like member 15a, the flange portion 15 _a2, 15 _b2 of 15b strength to be sufficiently strong to be formed by press molding, necessarily degreasing step is performed after press working or for finishing the surface smooth, Deformation is likely to occur in the parel polishing process of. Thus container-like member 15a flange portion is deformed, when combining 15b, FIG. 4 (A) is a portion of the flange portion 15 _a2 of the container-like member 15a is θ ° to problems such as that shown in Figure 4 occurs An example of bending is shown, and such a container-like member 15
When a is assembled and welded to a normal container-like member 15b,
The shape is as shown in FIG. 6B, and a hole shift a due to a decrease in coaxiality and a parallelism error b due to a surface inclination occur. If the main lens is constructed using such a grid electrode having a reduced dimensional accuracy, the resolution of the electron beam on the phosphor screen, which is an important characteristic of the color picture tube, is adversely affected. That is, the main electron lens formed between the third and sixth grids has a deterioration in lens performance due to an increase in aberration of the electrostatic lens due to a decrease in assembly accuracy, resulting in poor resolution.

For this reason, conventionally, a step of measuring the amount of deformation of the flange portion before assembly is required, and when the automation is performed, the flange deformation is directly introduced and causes a defect, etc. It was a big obstacle.

On the other hand, a hole 20 is formed in the container-shaped member 15a of the third grid 15, and this hole 20 is formed in order to detect the twist with the fluorescent screen surface when the electron gun is mounted in the neck after assembly. Are using. The holes 20 are designed to automatically detect the twist and suppress the twist to the minimum. For this purpose, a rectangular hole is generally considered to be advantageous, and an electrode having one container-shaped member has a rectangular hole 25 of 1 = 1 mm and m = 1.5 mm as shown in FIG. The member 24 is used as having a hole of the smallest size.

However, in the case where the electrodes are formed by making the container-shaped members face each other, the height of the members needs to be pressed down to a low dimension of, for example, about 2 mm. Therefore, from the viewpoint of maintaining the strength of the press die for making holes. It was the limit of press work that the hole was circular and the diameter was about 0.6mm.

For this reason, in such a conventional electron gun device, it is impossible to automate the twist detection, and it is necessary to manually perform the twist correction work by visual observation, which has a drawback that the productivity is lowered.

[Object of the Invention]

The present invention has been made to solve such a conventional drawback, and an object of the present invention is to form a single electrode by integrally forming an opening of a container-shaped member so as to face each other, and a flange portion. An object of the present invention is to provide an electron gun apparatus that facilitates automation of assembly without lowering the assembly accuracy even if it is deformed.

[Outline of Invention]

In order to achieve such an object, the present invention forms a plurality of cutout portions on the facing surface portion of the container-shaped member, and by these cutout portions when both members are assembled into a single electrode. The holes are formed.

Example of Invention

 Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 6 is a side view of an embodiment of the electron gun device according to the present invention. In the figure, the same parts as those in FIG. 2 are designated by the same reference numerals. The third grid 25 is composed of container-shaped members 25a and 25b, and a rectangular hole 25c is formed on the side surface by combining notches formed in the facing surface portions on the flange side of each member. Similarly, the fifth grid 27 is also composed of container-shaped members 27a and 27b, and the rectangular holes 27c are formed on the side surfaces, and the sixth grid 28 is also composed of container-shaped members 28a and 28b, and the rectangular holes 28c are formed on the side surfaces. Are formed.

Next, the method of assembling the electron gun electrode will be described with reference to FIG. 7 by taking the third grid 25 as an example.

Similarly to FIG. 3, the container-shaped member 25b is first set on the assembly jig 21. Then, a rectangular rod-shaped auxiliary jig 29 is inserted into the notches formed on both side surfaces of the container 25b. Next, the container 25a is set on the assembly jig 21,
At this time, the upper half of the auxiliary jig 29 is inserted into the notches formed on both side surfaces of the container 25a. Then, after fixing with the pressure jig 23, the flange portions are welded at a plurality of positions. At this time, an auxiliary jig 29 is inserted into the cutout portions of both members. Since the auxiliary jig 29 has a dimensional relationship as shown in FIG. 8, the flange portions _25a2 and _25b2 are A gap S is provided between them. Flange 25 _a2 during welding,
It is bent with a welding jig so that only the welded parts of 25 _b2 come into contact with each other. At this time, both members are the core metal 22 of the assembly jig 21.
Further, since the positioning is performed by the auxiliary jig 29, even if the flange portion is deformed, this does not affect the accuracy of the grid electrode after assembly.

In this way, it becomes unnecessary to measure the deformation of the flange portion before assembling which is conventionally required, and the assembling can be easily automated. Further, since the accuracy of the flange portion does not affect the assembly accuracy, the electrode dimensions can be made highly accurate and the performance can be stabilized. According to the above-mentioned embodiment, the assembling accuracy is improved by 50% as compared with the already sorted one, and the number of assembling steps is reduced to 1/5 of the conventional one by the automation.

Further, the twist detection at the time of mounting the electron gun on the neck can be automated easily from this aspect, because the rectangular hole formed by combining the cutouts can secure a sufficient hole size.

Although the third grid has been described in the above embodiments,
The same applies to the fifth and sixth grids. Even if the notch and the hole synthesized by the notch are circular, an effect close to a rectangle can be obtained.

Next, another embodiment will be described.

Generally, in an electron gun, as shown in FIG. 9, an electrode is assembled by stacking a plurality of container-shaped members 31, 32, 33, 34 so that the centers of the cylindrical portions which are the passages of the electron beams coincide with each other. These members 31 to 34 are made to have their central axes aligned by simultaneously inserting them into a mandrel having an outer diameter equal to the minimum cylindrical inner diameter of each member. As shown in FIG. 10, the tip of the cylindrical portion of the members 31 to 34 maintains an accurate cylindrical shape after forming by press working, but after barrel polishing and annealing steps, the sticking to the tip Due to the part falling in the center direction and deforming due to the release of residual stress,
As shown in FIG. 11, the tip diameter tends to decrease by about 0.005 to 0.02 mm. In order to eliminate such a problem, it is assembled using a mandrel with an outer diameter that is about 0.025 mm smaller than the inner diameter of the part other than the tip of the cylindrical part, but this does not exactly match the center of each member, Coaxiality becomes poor.

Therefore, as shown in FIG. 12, it is conceivable to form a taper on the tip inner peripheral surface of each member 31 to 34. Thickness
In the case of a 0.2 mm cylindrical part, by providing a taper shape of C0.05 to 0.15, it can be easily inserted into the mandrel from either direction, and the difference between the cylindrical part inner diameter and the mandrel outer diameter is 0.01 mm. can do. In this way, even if the tip of the cylindrical part is deformed inward, the inner diameter of the end does not become smaller than the inner diameters of other parts, and it also has a guide function during insertion into the assembly mandrel. Will get better.
Further, the difference between the inner diameter of the cylindrical portion which becomes the electron beam passage hole and the outer diameter of the mandrel can be set to 50% or less of the conventional value, the electrode accuracy is improved, and the deviation of the electron beam trajectory is reduced.

〔The invention's effect〕

As described above, according to the present invention, the notch is formed in the facing surface of the container-shaped member, and the holes are formed in the notch when assembled in a single electrode. Assembling accuracy can be improved without being affected by the deformation of the flange portion, and automation can be facilitated to significantly improve productivity.

[Brief description of drawings]

Fig. 1 is a structural drawing of a shadow mask type color picture tube.
FIG. 1A is a front view of a conventional electron gun device, FIG. 2B is a side view of the same, FIG. 3A is a front sectional view of a container-like member at the time of assembly, and FIG. FIG. 3 (C) is a front view of the assembly jig, FIG. 3 (C) is a cross-sectional view of the grid after assembly, FIG. 4 (A) is a side view of the container-like member with the flange portion deformed, and FIG. 4 (B) is Similarly, a side view of the grid after assembly, FIG. 5 is a side view of another container-shaped member, FIG. 6 is a side view of an embodiment of the electron gun device according to the present invention, and FIG. 7 (A) is a jig. Fig. 7 (B) is a side view of the grid after assembly, Fig. 7 (B) is a side view of the same, Fig. 8 is a side view of the grid for showing the dimensions of the auxiliary jig, and Figs. It is sectional drawing which shows an example. 25 ... 3rd grid, 27 ... 5th grid, 28 ...
… Sixth grid, 25a, 25b, 27a, 27b, 28a, 28b… Container-like member, 25c, 27c, 28c… Hole, 21 …… Assembly jig, 22…
… Core metal, 23 …… Pressure jig, 29 …… Auxiliary jig.

Claims (1)

[Claims] 1. An electron beam source, and a plurality of electrodes constituting a main electron lens section for focusing an electron beam emitted from the electron beam source on a phosphor screen, and at least one of the electrodes. In an electron gun device in which openings of a plurality of container-shaped members are opposed to each other and integrated to form a single electrode, a plurality of cutouts are formed in opposing surface portions of the plurality of container-shaped members, respectively. An electron gun device in which one twist detection hole having an area obtained by combining the areas of these notch parts is formed by these adjacent notch parts when assembled in one electrode.