JPS6199250A - Electron gun cathode structure - Google Patents

Abstract

PURPOSE:To keep constant the distance between the G1 electrode and the top surface of cathode by welding a stator for fixing cathode supporting material fixing three cathodes by inserting it into the G1 electrode to a support segment embedded in a suport rod fixing a group of electrodes. CONSTITUTION:A cathode supporting material 11 consisting of insulator fixing three cathodes 10 in the inline type electron gun electrode structure is inserted into the G1 electrode 21 so that distance between the top surface of cathode 10 and G1 electrode 2 becomes equal to the predetermined value, the lower surface of saod supporting material 12c is pressed with the pressurizing leg portion 24A formed by bending the one end of H-type stator 24 intot he shape of letter L, and the H type other end fixing portion 24B is fixed by welding to a stator fixing material 9 embedded to two insulator supporting rods 7 for fixing respective electrodes. Therefore, the distance between the G1 electrode 2 and top surface of cathode 10 does not change during manufacture and operation and fluctuation of cathode shielding voltage can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a cathode ray tube electron gun 'I! This invention relates to improvements to pole structures.

(Prior Art) In color cathode ray tubes, an in-line type electron gun electrode structure having an integrated electrode structure 4 is generally used. As shown in FIG. 2, in the in-line electron gun electrode structure, only the three cathodes 10 of the chest electrode structure 1, which generate all three electron beams, are electrically independent and are arranged in sequence in front of the cathodes 10. G1 electrode 2, G2t, pole 3 and main electron lens forming electrode. G3 electrode 4 and G4 electrode 5 are electrically common to structure 4.

Drive by a video signal keeps the common G1 electrode 2 at approximately 0■, and each cathode 10 has a cathode drive that changes the brightness by superimposing the video signal on the cathode cutoff voltage, which is a positive bias voltage that cuts off the cathode radiation current. method is adopted. Therefore, when using this type of color cathode ray tube, Gl, G2 in the same tube
Since the electrode 2.3 is electrically common to a plurality of cathodes, variations in cathode cut-off voltage for each cathode 10 should be as small as possible in order to optimize image quality in color receiver circuit design. desirable.

The cathode cutoff voltage is determined by the distance d between the electron emitting surfaces of the pole 2 and the cathode 10, once the structural dimensions of the poles 2 and 3 are determined. An oval disk-shaped cathode support made of an insulating material such as ceramic and having an outer surface that fits into the 01 electrode 2, which is a roughly oval closed cylindrical body with holes 21R, 21G, and 21B. I have 11.

The peripheral part is provided with an abutting part 12A that comes into contact with the perforated surface 22 of the Glt pole 2, and a recess 12B in the center.
2B has a structure in which three cathode support cylinders 13 are fixed to the openings 21R, 21G, and 21B by caulking or the like. Insert the cathodes 10 in the cap-shaped cylinder into the cathode support tube 13, and lower the top electron emitting surfaces of the three cathodes 10 by a predetermined distance d from the top surface of the abutting portion 12A of the cathode support 11 toward the recess 12B. Each cathode 10 is fixed by spot welding or the like at the lower end of the cathode support cylinder 13, and this cathode support 11
into the G1 electrode 2 of the electron gun structure, and its abutment 11f
i12A is tightly fixed on the closed surface of G1 electrode 2, and the lower surface 12
0 shown in the perspective view of FIG.
By welding and fixing the three cathodes 10 to the side wall 23 of the G1 electrode 2, the positions of the three cathodes 10 relative to the closed surface of the G1 electrode 2 can be simultaneously determined with high precision.

(Problem to be Solved by the Invention) However, in the cathode assembly 1 described above, the stator 14 is
l: When welding and fixing to the side wall 23 of the electrode 2, the side wall 23 is deformed, and the p-hole drilling surface 22 is bent due to the deformation, and the distance d between the top surfaces of the G1 electrode 2 and the cathode 10 is adjusted to the set distance d. On the other hand, it is displaced for each cathode, and its value also varies among each cathode 10, resulting in large variations in cathode cutoff voltage. Further, during operation of the cathode ray tube, the top of the rainbow cathode 10 is normally 750 to 800 dia.
It is heated to about ℃, and by using conduction and radiation of this heat, G
The closed surface 22, side wall 23, and cathode support 11 of the lt electrode 2 are heated to a high temperature, and therefore the stator 14 is also heated to a high temperature.

As a result, the side wall 23 of the G1 electrode 2, the metal stator 14
thermally expands, and the solid state of the cathode support 11 relative to the Glt electrode 2 slows down, causing the cathode cutoff voltage to fluctuate over time, and this variation to vary non-uniformly among the three cathodes. Alternatively, the cathode support 11 is attached to the side wall 23 of the G1 electrode 2.
Once fixed by welding with the stator 14, the G1 electrode 2
It is impossible to take out the cathode support 11 without deforming or destroying it, and after fixing the cathode support 11 with the stator 14, the distance between the G1'lE electrode 2 and each cathode 10 is outside the standard value. Even if this was detected, the entire electron gun assembly had to be discarded as defective, resulting in a large amount of waste.

In view of the above points, it is an object of the present invention to provide a cathode structure in which the initially set distance between the GIN pole and the top surface of the cathode does not vary from a predetermined value.

(Means for Solving the Problem) The present invention suppresses a cathode support made of an insulator on which a cathode is fixed at one end within the 01 electrode so that the distance between the GIN electrode and the top surface of the cathode becomes a predetermined value. The other end of the stator to be fixed is fixed to a plurality of supports embedded in an insulator support rod on which the electrodes of the electron gun electrode assembly are implanted and fixed.

(Examples) Hereinafter, the present invention will be described in detail using examples according to the drawings.

FIG. 1 shows a perspective view of an in-line electron gun electrode assembly according to an embodiment of the present invention, and the same parts as in FIGS. 2 and 3 are given the same reference numerals.

As in the conventional electron gun electrode structure, GIN, pole 2, G2 electrode 3, G3 electrode 4, and G4 electrode 5 (not shown) are arranged facing each other in sequence, and each electrode support is embedded in two insulator support rods 7. This maintains a predetermined electrode spacing. The insulator support rod 7 on the open end brim-shaped edge side of the closed cylindrical body G1 electrode 2 has a second
As shown in the figure, an L-shaped lens support 8 is buried 1
The electron gun electrode assembly is fixed by welding to a support lead of a glass stem (not shown), and the electron gun electrode assembly is fixed to the glass stem.

However, in the present invention, two L-shaped stator supports 9 are embedded and fixed in each insulator support rod 7 between the brim-shaped edge of the 01 electrode 2 and the lens support 8.

Needless to say, the lens support 8. Each stator support 9 is electrically insulated from itself and from other electrodes.

The closed cylindrical body G of the fc electron gun electrode assembly assembled in this way
1i [As in the conventional case, a disk-shaped cathode support 11 is inserted into the electrode 2, which is made of an insulating material such as ceramic and matches the outer shape of the 1i111 portion of the G1 electrode 2. Cathode support 11
is a predetermined distance d between the three cathodes 10 and the upper surface of the abutting portion 12A.
Lower the cathode support so that its top electron emitting surface is located @
13 in advance. The cathode support 11 inserted into the closed base cylindrical body Gll and the other electrode 2 has its abutment surface 12A aligned with G11.
The closed base surface of the ft pole 2 is brought into close contact with the lower surface 12c, and the lower surface 12c is pressed with the crimping foot 24A formed by bending one end of the IF-shaped stator 24 into a t-L shape, and the other end fixing portion 24B of the H-shape is pressed. are fixed by welding them to the stator support 9, respectively. Here, three cathodes 10 are attached to the abutment surface 12A of the cathode support 11.
Since the top position of the G1 electrode 2 does not need to be measured through the microbeam aperture, it can be positioned with extremely high precision and easily based on the abutting surface 12A.
Accordingly, the positions of the three cathodes 10 relative to the closed surface of G1@pole 2 can be determined simultaneously with high precision and easily.

In this electron gun electrode structure, the stator 24 of the cathode support 11
is not fixed to the side wall 23 of the G1 electrode 2, but is fixed to the stator support 9 which is separately installed in the insulator support rod 7 independently of the Glt electrode 2. The side wall 23 will not be deformed, and the perforated surface 22 will not be bent, causing the distance between the tops of the G1 electrode 2 and the cathode 10 to deviate from the predetermined value for each cathode. It is possible to prevent variations in the cut-off voltage.

Furthermore, the fixed end of the stator 24 of the cathode support 11 is connected to the G1 electrode 2.
Even if the side wall expands thermally due to the heat of the heating fibers in the cathode 10, the fixation of the cathode support 11 to the G1 electrode 2 will not loosen, and the cathode cutoff voltage will fluctuate over time. This will be prevented. Alternatively, as described above, the fixed end of the stator 24 of the cathode support 11 is not on the side wall of the 01 electrode 2, so that the cathode support 1 once fixed inside the G1 electrode 2
1, stator supports 91 and 01 of the stator 24.
By cutting the H-shaped fixed part between the electrodes 2, it is possible to take out the 01 electrode 2 without causing the same deformation. If it is detected that there is a defect such as a scratch on the top of the cathode, the original electron gun electrode assembly can be reused by replacing only the cathode assembly. Also, stator 24
It goes without saying that the present invention is applicable even if the shape is not limited to the H-shape, but one, for example, four L-shapes.

(Effects of the Invention) As described above, according to the present invention, the cathode support on which a plurality of cathodes are supported and fixed is pressed and fixed into the G1 electrode so that the top of the cathode is a predetermined distance from the abutment surface of the cathode support. Because one end of the stator is welded and fixed to the stator support buried in the insulator support rod separately from the 01 electrode, the distance between the G1 electrode and the top surfaces of multiple cathodes that was initially set is fixed by the fixing work or the cathode wire. It is possible to obtain a cathode body that does not fluctuate due to the influence of heat from heated fibers during tube operation. Furthermore, the cathode assembly fixed within the G1 electrode can be taken out without deforming the 01 electrode at all, and the electron gun electrode assembly can be recycled, so its industrial utility value is extremely high.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an in-line electron gun electrode assembly according to an embodiment of the present invention; FIG. 2 is a vertical sectional view of a conventional in-line electron gun electrode assembly; FIG. 3 is a perspective view of the L-shaped stator. 1... Cathode structure, 2... G1 electrode, 3
...G2 electrode, 4...G3 as pole, 5.
...G4 electrode, 7...Insulator support rod, 8
... Lens support, 9 ... Stator support, 10 ... Cathode, 11 ... Cathode support, 12A ... Protrusion Part, 12B... Concavity, 13... Cathode support tube, 14.24...
. . . Stator, 22 . . . Opening surface of the closed base cylindrical GIN pole, 23 . . . Side wall thereof.

Claims (1)

[Claims] A cathode support made of an insulator to which a cathode is fixed is pressed with one end to the side where the G1 electrode hole is formed so that the distance between the G1 electrode of the cathode ray tube electron gun and the top surface of the cathode is a predetermined value. An electron gun cathode assembly characterized in that the other end of the stator is fixed to a plurality of supports embedded in an insulating support rod in which an electrode group of the electron gun electrode assembly is implanted and fixed.