JPS6318295B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of assembling an electron gun device suitable for application to various cathode ray tubes including color television picture tubes.

In order to improve the sharpness of the image in a television receiver, it is possible to modulate, for example, the horizontal scanning speed of the electron beam on the fluorescent surface of the picture tube, thereby modulating the substantial amount of light emitted by the fluorescent surface. It will be done. In this manner, in order to modulate the beam scanning speed, the electron beam is deflected, for example, in the horizontal scanning direction using the modulation signal, thereby substantially modulating the beam scanning speed. Such beam deflection can be achieved by various methods, for example, as shown in FIG. (acceleration electrode), third grid G3 (first
anode electrode), 4th grid G4 (focusing electrode), 5th grid
In an electron gun device in which grids G5 (second anode electrodes) are sequentially arranged, the fourth grid G4 is
There is one that is composed of electrode parts G4a and G4b that are divided into two parts with respect to the 0 direction of the axis of the electron gun. As shown in FIG. 2, these electrode portions G4a and G4b are each formed into a cylindrical shape, and their mutually opposing end surfaces maintain a uniform spacing in each portion, and these end surfaces each have a horizontal plane including the axis 0. They intersect obliquely, and are perpendicular to the vertical plane containing the axis 0. In such a configuration, the fourth
A fixed low voltage is applied to each electrode portion G4a and G4b of grid G4 to configure a unipotential main electron lens by cooperation with third grid G3 and fifth grid G5, and both electrode portions A scanning speed modulation signal in the horizontal direction of the beam is applied between G4a and G4b, and a potential gradient according to the modulation signal is created in the horizontal direction (direction along the plane of the paper in FIG. 1) by the inclined end surfaces of both electrode portions G4a and G4b. The electron beam is deflected in the horizontal direction to modulate the scanning speed in the horizontal direction.

However, when using such a method, the machining work to form sloped end faces on the electrode portions G4a and G4b is very difficult, and since the shape of the opening formed by the sloped end faces is elliptical, discontinuous cutting is required. It is easy to produce "burrs", which necessitates the use of a combination of flat processing and barrel processing, making it unsuitable for mass production and resulting in high costs. Furthermore, there is a drawback that it is relatively difficult to assemble the inclined end surfaces of both electrode parts G4a and G4b while maintaining the required spacing between each part.

In addition, in such a configuration, the distance l that receives the horizontal electrostatic deflection of the electron beam is, in other words, the range in which a horizontal potential gradient occurs between the electrode portions G4a and G4b. G
This is the direct projection length of the slit between 4b and 0 on the axis 0.
On the other hand, each electrode part G4a and G4b needs to have a certain length of the cylindrical part whose inclined end surface is not cut in order to maintain its mechanical strength. In an electron gun whose length is shortened, the effective length l may become insufficient to receive the electrostatic deflection.

Further, as another deflection method, as shown in FIG. 3, for example, the first to fifth grids G1 to G5 are sequentially provided as described above,
The grid G4 is divided into two parts along a vertical plane along the axis 0, each of which has a mere semi-cylindrical shape, and is composed of two electrode parts G4a and G4b which have a cylindrical shape as a whole, and FIGS. In the same manner as explained in , a modulation signal is applied between both electrode portions G4a and G4b, and both electrode portions G4a and G4b are adjusted according to this modulation signal.
There are some methods that deflect the beam by applying a potential gradient in the horizontal direction. In such a configuration,
The distance l subjected to electrostatic deflection is larger than that of the structures shown in FIGS. 1 and 2.

However, when using such vertically divided semi-cylindrical electrode parts G4a and G4b, when fixing these electrode parts G4a and G4b, there is a radial direction,
In particular, when an external force in the vertical direction is applied, this deforms, impairs the roundness, and causes distortion in the electric field. That is, in this electron gun, the main electron lens system is formed by the cooperation of the fourth grid G4 and the third and fifth grids G3 and G5 in the preceding and subsequent stages. , the roundness of the end facing the third and fifth grids G3 and G5 is low, and the third and fifth grids G3 and G4 of the fourth grid G4 constituted by both electrode portions G4a and G4b. Since both ends facing grid G5 are wide open, there is a drawback that the electric field within grid G4 is easily disturbed by external influences.

In order to avoid such drawbacks, as shown in FIGS. 4 and 5, the fourth grid G4 for forming the deflection electric field is constituted by two electrode portions G4a and G4b. Part G4a
A cylindrical cap 1 in which G4b and G4b are each made of metal.
1A and 11B, and substantially semi-cylindrical wall portions 12A and 12B, has been provided by the applicant. As shown in FIG. 5, the cylindrical caps 11A and 11B have cylindrical portions 13A and 13B, respectively, and end plates 14A and 14B provided at their outer ends. are center holes 15A and 15B
is drilled. In the illustrated example, center holes 15A and 1
5B are provided with inner cylindrical parts 16A and 16B that protrude concentrically into the cylindrical parts 13A and 13B. Caps 11A and 11B having such a structure are manufactured by press molding.

On the other hand, the wall portions 12A and 12B each form a vertically divided substantially semi-cylindrical shape, and reinforcing ribs 1 protrude outward at corresponding positions on both ends, that is, on substantially the same circumference.
7A, 18A and 18B, 17B are formed.
These semi-cylindrical wall portions 12A and 12B can be manufactured by press working.

Then, both semi-cylindrical wall portions 12A and 12B are electrically and mechanically attached to each one of the caps 11A and 11B, respectively. This attachment is performed between the cylindrical parts 13A and 16A of each cap 11A and 11B.
Wall parts 12A and 12B between 13B and 16B respectively
Insert one end of each of the caps having ribs 17A and 17B so that the cylindrical center axes of these wall portions 12A and 12B coincide with the center axes of both caps 11A and 11B, and Each of the caps 11A and 11B and the wall portions 12A and 12B are spot welded at several locations.

In this way, the electrode parts G4a and G4b, which are formed by integrating the caps 11A and 11B and the wall parts 12A and 12B, respectively, are as shown in FIG.
Between the third grid G3 and the fifth grid G5, both caps 11A and 11B are arranged on the axis 0, and between both caps 11A and 11B, both cylindrical wall parts 12A and 12B are on the same cylindrical surface without contacting each other. , and both wall surfaces 12
Each wall portion 12A and 12B connects each cap 1 so that the gap between A and 12B runs along a vertical plane.
It is arranged to extend between 1A and 11B.
Then, the end portions of both cylindrical wall portions 12A and 12B opposite to the end portions attached to the respective caps 11A and 11B are attached to the other caps 11B and 11B, respectively.
Between the cylindrical parts 13B and 16B of 1A, and 13A
and 16B, these caps 11B and 1
Insert it so that it does not come into contact with 1A. Therefore, the ribs 18A and 18B at the end of each cylindrical wall surface portion 12A and 12B on the opposite side from the side to be welded to each cap 11A and 11B are smaller than the ribs 17A and 17B on the side to be welded. Keep the height low.

According to such a configuration, the effective length l of the electron beam deflection can be set to cover almost the entire length of the fourth grid G4, and even when the length of the fourth grid G4 is shortened, the effective length l can be set to the distance l over which the electron beam is deflected. The length l can be made sufficiently large. Further, since the caps 11A and 11B are arranged at both ends of the grid G4, the mechanical strength is high, and disturbances in the electric field due to the influence of the surrounding conditions can be prevented.

However, with such a configuration, the number of parts increases, and the wall portions 12A and 12B
and the cap 11B which should be electrically insulated from these.
and 11A, which may impede high frequency modulation characteristics.

The present invention provides a method for assembling an electron gun device which eliminates such drawbacks and allows easy and reliable assembly of an electron gun device.

An example of the present invention will be described with reference to FIGS. 6 to 8. In this example as well, the first to fifth grids G1 to G are arranged on the same axis 0 with respect to the cathode K.
5 are arranged sequentially, and the third to fifth grids G3 to G
This is a case where an electrostatic deflection electric field is desired to be obtained in the fourth grid G4 to which a low voltage is applied in an electron gun in which a unipotential type main electron lens is formed between the two electron beams.

Also in the present invention, the grid G4 is constituted by two electrode portions G4a and G4b. These two electrode parts G4a and G4b each have an axial center of 0.
A wall portion 21A having a substantially semi-cylindrical shape centered on
and 21B, and semicircular arc-shaped flange plate portions 22A ₁ , 22A ₂ and 22 provided at both ends thereof so as to be bent inward in a substantially perpendicular direction.
It is composed of B ₁ and 22B ₂ . These electrode parts G
4a and G4b are arranged symmetrically about axis 0, so that a slit S is formed between both electrode parts G4a and G4b, and this slit S is located in a vertical plane passing through axis 0. .

These electrode parts G4a and G4b can be formed by punching and press-molding a metal plate, respectively.

In the method for assembling an electron gun device according to the present invention, the electrode portions G4a and G4b can be arranged in a desired positional relationship by using a spacer and a jig for holding the spacer. The spacers include two spacers 30 and 31 as shown in FIG.
When assembling the electron gun, a pair of spacers 30 and 31 are interposed between the fourth grid G4 and the third grid G3, with the spacers 30 on the grid G4 side, and the fourth grid G4 and 5th
Another set of spacers 30 and 31 is similarly interposed between the grid G5 and the grid G4, with the spacer 30 facing the grid G4 side. One spacer 30 of each set of spacers includes semicircular arc-shaped flange plates 22A ₁ and 22B ₁ of the pair of electrode portions G4a and G4b of grid G4,
A circle formed by 22A ₂ and 22B ₂ , that is, a round table 32 that is inserted into the electron beam passage holes 23 and 24 to define the beam passage holes, and a slit between the electrode portions G4a and G4b on both sides thereof. Protrusions 33 and 34 are inserted into the electrode portions G4a and G4b to define the distance between the electrode portions G4a and G4b.
In addition, protrusions 35 and 36, 37 and 38 are provided on the circumferential surface of each spacer 30 and 31 in each set, and by holding these protrusions with an appropriate jig (not shown), each spacer in each set can be 30 and 31
is arranged coaxially with the axis 0, so that each electrode portion G4a and G4b of the grid G4 is arranged at a predetermined position. For example, after assembling the electron gun, spacers 30 and 31 are provided, respectively.
take away.

Then, as described above, the fourth grid G4
A common fixed voltage required for forming a unipotential main electron lens between the third grid G3 and the fifth grid G5 is applied to both electrode parts G4a and G4b, and both electrode parts G4a and G4b are G
For example, a horizontal scanning speed modulation signal voltage is applied between G4a and G4b. Then, in response to this modulation signal voltage, a horizontal electric field is generated in the slit S between the semi-cylindrical wall surfaces 21A and 21B of both electrode portions G4a and G4b, and this permeates into the grid G4, so that the modulation signal is Accordingly, the electron beam emitted from the cathode K and passing through the fourth grid G4 is electrostatically deflected, and the scanning speed is modulated.

As described above, in the electrode structure obtained according to the present invention, for example, the fourth grid G4 is composed of two electrode parts G4a and G4b, and a potential gradient is formed between them. Since an electric field is formed between the vertically divided cylindrical wall portions 21A and 21B, the effective length of deflection can be increased. And both electrode parts G4a and G4b
Although it has a vertically divided structure, each end thereof has a flange plate portion 22 that protrudes inward in the right angle direction.
Mechanical strength can be maintained sufficiently by providing A ₁ , 22A ₂ , 22B ₁ and 22B ₂ ,
Deformation can be avoided even if an external force is applied during assembly or the like.

Furthermore, since a ring shape and flange plate portions are provided at both ends facing the third grid G3 and the fifth grid G5, disturbances in the electric field due to external influences are prevented. can also be avoided.

Furthermore, since both electrode portions G4a and G4b can be manufactured by stamping and press molding, they can be manufactured in mass production.

In the assembly, by applying the spacers 30 and 31, both wall portions 21A and 21B can be assembled in a predetermined positional relationship with high accuracy and reliably.

The illustrated example is a case where the present invention is applied to a single beam single electron gun, but the present invention can also be applied to various electron guns including a double beam single electron gun in which a common grid is provided for a plurality of cathodes. Can be done. In addition, in the above example, the electrode that obtains the potential gradient in the direction perpendicular to the axis 0 is the low voltage side electrode that constitutes the unipotential main electron lens. This can be applied when the electrode is a low-voltage side electrode of a bipotential type main electron lens, another electrode, or an electrode of another type of electron gun.

Furthermore, in the above example, a potential gradient for deflecting an electron beam in a horizontal direction perpendicular to the axis 0 is obtained, but the present invention can be used to obtain a potential gradient in other directions intersecting the axis 0. The invention can also be applied.

[Brief explanation of the drawing]

1, 3 and 4 are sectional views of conventional electron guns, FIGS. 2 and 5 are perspective views and sectional views of the main parts of FIGS. 1 and 4, and FIG. 6 is a sectional view of a conventional electron gun. Section 7 of an example of an electron gun device obtained by the present invention.
The figure is a perspective view of the fourth grid, and FIG. 8 is a perspective view of a spacer used in the method of the present invention. K is a cathode, G1 to G5 are first to fifth grids, G4a and G4b are electrode parts, 21A and 21
B are the cylindrical wall portions 22A ₁ , 22A ₂ , 2
2B ₁ and 22B ₂ are the flange portions thereof.

Claims (1)

[Claims] 1. A pair of electrode parts each consisting of a wall part having a substantially semi-cylindrical shape and a semi-circular arc-shaped flange plate part provided at both ends thereof are arranged around the axis so that a slit is formed between the two electrode parts. In the method for assembling an electron gun device, the electrodes are arranged to apply a required signal voltage between the electrode portions of the pair to generate a potential gradient in a direction intersecting the axis, the flange plate of the pair of electrodes A first spacer and a second spacer, each of which has a cylindrical part on one surface that defines an electron beam passage hole surrounded by opposing parts in the same plane, and a second spacer are used as a set. A method for assembling an electron gun device, characterized in that electrode assembly is performed by setting a distance between the electrode and an adjacent electrode.