JPS5825550Y2 - Electron gun electrode structure for cathode ray tube - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electron gun electrode assembly for a color cathode ray tube, and particularly to an electron gun having a structure in which a plurality of cathodes are arranged in a straight line, a so-called in-line type electron gun electrode assembly.

Recent color cathode ray tubes have simplified the cathode ray tube device by saving deflection power and making it possible to converge multiple electron beams at all points on the scanning screen without dynamically performing convergence. is being transformed.

In order to meet these requirements, the cathode ray tube electron gun used has multiple cathodes arranged close to each other in a straight line on the same plane, and each electrode is integrated, miniaturized, simplified, and precisely An in-line electron gun with an assembled structure is used.

In such conventional in-line electron guns, the positioning of the electron gun electrode assembly requires careful manufacturing techniques, but it is often the case that the electron gun electrode assembly is in its final state. The spacing has changed from the design value, requiring correction work, and this correction work may cause an abnormality in the direction of movement of the electron beam, which may have an unfavorable effect on the reproduced image on the fluorescent surface. There were drawbacks.

The present invention eliminates the above drawbacks and provides an electron gun electrode structure that is easy to modify.

First, before explaining the present invention, let's take a look at the conventional pi-
The structure of a potential cathode ray tube electron gun electrode structure will be described with reference to FIGS. 1 and 2.

That is, the electrode assemblies include three cathode assemblies 1 which are insulated from each other and arranged in a line with equal distances S maintained therebetween, and a G1 electrode 2, a G2 electrode 3, which are arranged in sequence in the direction of electron beam propagation in opposition to these cathode assemblies 1. Consisting of a G3 electrode 4, a G4 electrode 5, and a shielding magnetic pole 6, each electrode except the shielding magnetic pole 6 is fused and fixed so as to be supported by two insulator support rods 8 via each electrode support part 7. and maintains a predetermined electrode spacing.

Each through hole 2R22G, 2B: 3R, 3G, 3B; 4 through which the electron beams of G1 electrode 2, G2 electrode 3, and G3 electrode 4 pass.
R,, 4G1.4B1 and 4R2, 4G2.4B2 are also aligned in a line with equal distances S, so that the electron beams emitted from the three cathodes IR, 1G, and IB of the cathode structure 1 follow parallel paths. It is accelerated to move above 9R99G and 9B.

The distance S' between the through holes of the G4 electrode 5 is somewhat larger than the above-mentioned S, and the two outer sides of the main electron lens formed in each corresponding electron beam through hole gap between the G3 electrode 4 and the G4 electrode 5 are When there is no deflection magnetic field, the two outer electron beams form a central electron beam at the center on a color selection mechanism (generally a shadow mask) placed near the phosphor surface. It becomes electrostatically concentrated.

In order to simplify the explanation, electrodes within the plane shown in FIG. 2 will be described below unless otherwise specified.

The cathode assembly 1 includes a cathode 1R assembled by fitting a cap-shaped cylinder 12 coated with a thermionic emission material layer 11 on the top surface into a cathode-side cylinder 13 in which a heating fiber 10 is housed, and the cathode 1R. It consists of a cathode support tube 14 arranged coaxially with each other and a cathode structure support 20 that supports and fixes the cathode support tube 14, and the cathode 1R and the cathode support tube 14 are welded and fixed at a lower welding point 16. , the cathode support tube 14 and the cathode structure support 20 are:
An annular edge portion 1 extending in the shape of a flange at the upper end of the cathode support tube 14
It is fixed by welding at 5.

On the other hand, the G1 electrode 2 and the G2 electrode 3 are provided with electron beam transmission holes 2R and 3R having a diameter of about 0.5 to 0.9 mm, and are opposed to the thermionic emissive material layer 11 of the cathode 1R.

However, as is well known, the electron beam cutoff voltage characteristics of the cathode-front electron gun are determined by the distance d between the surface of the thermionic emissive material layer and the surface facing the electrode 61, so careful manufacturing techniques are required for positioning the two. I need.

For this reason, when each electrode is fused and fixed to the insulator support rod 8, the cathode plate IR is not attached in the cathode structure 1, and the composite body consisting of the cathode support tube 14 and the cathode structure support 20 is connected to a plurality of electrodes. The cathode 1R is fused and fixed to the insulating part support rod 8 so as to face each other, and after the fusion and fixing operation is completed, the cathode 1R is inserted and fixed from the lower open end of the cathode support cylinder 14.

In this case, the spacing d between the opposing surfaces of the thermionic emissive material layer 11 and 61 electrode 2 is determined by an air probe inserted from the opposite direction of the cathode structure 1 through the electron beam transmission holes 2R, 3R, etc. of the G1 electrode 2, G2 electrode 3, etc. While measuring the spacing by directly connecting it to an air micrometer, determine the optimal insertion position of the electrode IR when it shows a predetermined value, and connect the lower end of the cathode side cylinder 13 of the cathode 1R with the cathode support. A method is used in which the tube 14 is fixed by welding.

However, even if the electrode spacing d is determined to a predetermined value in this manner and the cathode is fixed by welding, this is considered to be due to variations in dimensions during the manufacture of the cathode 1R and cathode support tube 14 parts.

If there is play in the mutual fitting, or if the cathode structure support 20 or the air probe is inserted, its shoulder is locked in the through hole of the electrode (for example, through hole 3R of G2 electrode 3) and then removed. In the final finished state of the electron gun assembly, this electrode spacing is d often changes.

Therefore, after welding the cathode 1R and the cathode support cylinder 14, or after completing the final finishing of the electron gun assembly, the air probe is inserted again and the electrode spacing d is remeasured, and it is determined that the electrode spacing d is outside a certain value. Use tweezers etc. to remove the cathode structure support 2.
Correction work is performed to move 0 up or down a small distance in the direction of the axis 9R to bring it within a predetermined value.

However, it is difficult to correct the thermionic emissive material layer 11 of the cathode so that it is always perpendicular to the axis 9R of the electron gun, and the correction causes abnormalities in the traveling direction of the electron beam, resulting in the reproduced image on the fluorescent surface. It has the disadvantage that it tends to have an undesirable effect on

Generally, the cathode structure support 20 has a shape as shown in FIG. 3A for the central cathode 1R, and as shown in FIG. 3B for the cathodes 1G and IB on both sides.

That is, a through hole 22 that fits into the cylindrical portion of the cathode support tube 14 is bored in the center of the rectangular surface 21 to which the brim-shaped ring edge 15 of the cathode support tube 14 is welded, and a pair of rectangular surfaces 21 are formed. The sides of the bent side are bent at right angles and extended in a band shape on both sides of the bent side, and a plurality of notches 24 are provided at the tip of the valley to increase the strength of the fusion bond with the insulating support rod, and four support arms are formed. 23 is formed, and the middle part thereof is folded back to make the width narrower than the width of the side of the rectangular surface 21 where the support arm 23 is not provided, so that the cathode assembly 20 is integrally constructed.

When the electron gun structure is thus constructed, the cathode structure support 2
Two pairs of support arms 23 of 0 are fixed to be supported by two insulator support rods 8, and the cathodes 1R11G and IB are supported and fixed to the cathode structure support 20 via the cathode tube 14. Since the cathode 1R is supported and fixed astride the G1 electrode 2, the resistance to deformation is extremely high. It will be extremely difficult to raise and lower it.

Therefore, it is extremely difficult to correct the electrode spacing d as described above, and those that fail to achieve the predetermined spacing have to be discarded as defective products.

This invention eliminates the above-mentioned drawbacks, and even if the cathode structure support has a strong support structure in which the cathode is supported in a straddling manner by two pairs of support arms, the thermionic emissive material layer of the cathode and the 61 electrode The object of the present invention is to provide a cathode structure support that can facilitate the work of correcting the distance d, and a cutout is provided in a part of the band-shaped support of the cathode structure support. It is a feature.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows a cathode structure support 30 according to an embodiment of the present invention, in which a rectangular surface 31 is provided with a through hole 32, and four band-shaped support arms 33 are integrally formed therein. The cathode structure support of the conventional structure has a plurality of notches 34 provided at the tip of each support arm which is folded back so that the width is narrower than the width of the pair of sides to which the support arm 33 is not attached. It is exactly the same as 20.

In the cathode assembly support of this embodiment, two rectangular notches 35 are newly provided in each folded portion of the two pairs of support arms 33.

Such a cathode structure support is a composite body in which the cathode support tube 14 and the ring edge 15 are welded and fixed to the rectangular surface 31 in the same manner as before, and are fused and fixed to the insulator support rod 8 facing a plurality of electrodes. After completing this fusion work, the cathode 1R is attached to the cathode support cylinder 14.
Thermionic emissive material layers 11 and 61 are inserted from the lower open end of the
The distance between the facing surfaces of the electrodes 2 is determined to be a predetermined value, and the lower end of the cathode side cylinder 13 of the cathode 1R and the cathode support cylinder 14 are welded and fixed.

The distance d between the cathode 1R and the cathode support cylinder 14 after welding can be easily adjusted by moving the notch 35 of the cathode structure support 30 up and down in the direction of the axis 9R of the electron gun using tweezers or the like. I can do it.

For example, if the distance between the opposing surfaces of the cathode top surface 11 and the G1 electrode 2 is larger than a predetermined value, the notch 35 of the support arm 33 is moved above the axis 9R toward the six electrodes 2 as shown in FIG. The rectangular notch is distorted into a parallelogram and the rectangular surface is centered at 9.
It is sufficient to move along R and stop when a predetermined distance d has been reached, and the distance d can be modified very easily.
1 can be easily corrected while keeping it perpendicular to the axis 9R of the electron gun, so there will be no problem of abnormality in the traveling direction of the electron beam after correction and the quality of the reproduced image.

In addition, it is possible to recycle all the electron guns with poor spacing, and it is also possible to expect the effect that it will not adversely affect the products manufactured using the electron guns.

Further, as shown in FIG. 6, even if the cutout portion of the support arm is circular or has another shape, the same effect can be expected.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a vertical section including the axes of three electron guns of a conventional in-line electron gun electrode assembly, FIG. 2 is a sectional view showing a vertical section perpendicular to FIG. 1, and FIG. 3A. is a perspective view showing the structure of the central cathode structure support used in the conventional cathode ray tube shown in FIG. 1, and FIG. Perspective view shown, No. 4
The figure is a perspective view showing the configuration of a cathode structure support according to an embodiment of the present invention, FIG. 5 is an explanatory view for explaining the function and effect of the cathode structure support shown in FIG. 4, and FIG. It is a perspective view showing the composition of another example. The reference numbers in the figure are as follows. 1: Cathode structure, I R, I G, I B: Cathode, 2:
G1 electrode, 3: G2 electrode, 4: G3 electrode, 5: G4 electrode, 6: Shielding magnetic pole, 7: Electrode support, 8: Insulator support rod,
9R99G, 9B: Electron gun axis, 20, 30.40
: Cathode structure support, 23, 33.43 : Support arm, 35
, 45: Notch.

Claims (1)

[Scope of utility model registration request] In an electron gun electrode assembly in which a cathode support is attached to an insulator support rod through four support arms, the portion of the support arm excluding the portion existing within the insulator support rod, which is the insulator support. An electron gun electrode assembly for a cathode ray tube, characterized in that openings are provided in exposed portions between the rod and the support.