JPS60105136A - Manufacturing method of electron gun for color picture tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a general method for an electron gun for color image receptivity, and more particularly to a method for processing a main lens electrode of an in-line electron gun.

[Background of the invention]

In general, the main lens aperture of an electron gun for a color picture tube has a great influence on focus characteristics, and in order to obtain suitable focus characteristics, it is desirable to make the main lens aperture 4+f=k as large as possible.

FIG. 1 is a cross-sectional view of the main parts of an example of a conventional pi-potential focusing type in-line electron gun. In the figure, IA, IB, and IC are cathodes that each emit three electron beams from the top surface, 2 is a control electrode that controls the electron beam, 3 is an accelerating electrode that accelerates the electron beam, and 4 is a convergence electrode for the electron beam. The lower focusing electrodes are 2A and 2B, respectively.

2C, 3A, 3B, 3C and 4A, 4B, 4C are electron beam passage holes for three electron beams. 5 is an upper focusing electrode, 6 is an anode, and the upper focusing electrode 5 and the anode 6 have three aperture holes 5A, 5B, 5C, and 6A provided on the bottom surface thereof facing toward each other. , 6B, and 6C form three main lenses corresponding to three electron beams.

In such an electron gun configuration, three cathodes IA
The three electron beams A, B, and C whose respective electron beam amounts are controlled by the signal potentials applied to , IB, and IC are as follows:
After receiving a slight focusing effect from the prefocus lenses formed between the facing holes of the accelerating electrode 3 and the lower collecting electrode 4, the light is focused by the respective main lenses formed by the upper focusing electrode 5 and the anode 6. , is subjected to a focusing action so that an image is formed on a fluorescent surface of a picture tube (not shown). At the same time, electron beams A on both sides
.

C is an external fli of the electron beam passing holes 6A, 6C of the anode 6 with respect to the electron beam passing holes 5A, 5C of the upper focusing electrode 5.
By using a known phase stage that centers a minute atom 11i on li, the three electron beams A, B, and C are brought into niconovarence at one point by setting the angle θ at full oblique angle. Note that 7 is a continuous electrode.

In an electron gun configured in this manner, the size of the imaged point on the fluorescent surface of the picture tube, that is, the focus characteristics, affects the sharpness of the image, so it is desirable to make it as small as possible. 1. To improve focus characteristics, the aperture of the main lens is generally increased.

FIG. 2 is a plan view of essential parts showing the upper surface of the upper focusing electrode 5. FIG. In the same figure, three electron beam passing holes 5A with a diameter
, 5B, and 5C are arranged in a straight line with an interval S, respectively. Further, electron beam passing holes 5A and 5B are provided to enlarge the main lens aperture as a means for completely improving focus characteristics.

It is necessary to increase the diameter of 5C. However, the electron beam passing holes 5A, 5B, and 5C of the upper focusing electrode 5, which is formed by pressing a nonmagnetic metal such as a stainless steel plate with a thickness of about 0.3 m, have a withstand voltage of the anode 6 shown in FIG. In order to improve the characteristics, it is necessary to make the aperture hole 41°7. Furthermore, to prevent deterioration of the rotational symmetry of the main lens electric field, the aperture depth t
Because it requires more than 1/2 of the diameter of the hole, due to problems in processing parts, the diameter is 0.8 to 1.0 + m as well as the hole spacing S.
n is limited to small dimensions. In addition, increasing the hole spacing S increases the convergence error at the trough point of the fluorescent surface during operation of the picture tube, and the horizontal dimension of the upper focusing lens 11r, 4M5 forming the main lens and the anode 6. There was a problem in that the positive characteristics deteriorated as the electron gun became larger and closer to the inner wall of the valve neck in which the electron gun was housed.

Further, in order to obtain good focusing characteristics, it is said that the circularity error (longer axis - shorter axis) of the electron beam passing holes 5A, 5B, 5C, etc. is desirably about 0.5% or less of the hole &D. Therefore, to assemble the electron gun, each electrode component is held on a jig (not shown) equipped with three core metals passing through each electron beam passage hole, and the heated multiform glass 8 is placed on a support 9.
This is done by crimping the In this case, since there is an error in the hole pitch S and hole diameter of each electrode component, the three core metals are set to be 0.02 to 0.03 m thinner than the hole diameter. Therefore, the electron beam passing holes 5A, 5B, 5, which are formed in the aperture holes, are deformed in the cup-shaped main body due to errors in manufacturing each electrode component and stress when the multiform glass 8 is crimped.
The roundness error that spreads to C and is measured when removed from the jig is approximately 0.05■ in the case of a hole edge, that is, the hole diameter D = 3
．． In the case of 9 key, it can reach about 1.3 chi. There was a serious drawback in that the electric field of the main lens was distorted due to the roundness, causing astigmatism in the electron beam and impairing focusing characteristics.

[Purpose of the invention]

Therefore, the present invention has been made in view of the above-mentioned conventional drawbacks, and its purpose is to reduce the above-mentioned side effects, enlarge the main lens aperture, and improve the assembly accuracy of an electron gun. For color picture tubes with improved focus characteristics' [! :l', The object of the present invention is to provide a method for manufacturing a sub-gun.

[Summary of the invention]

In order to achieve all of these objects, the present invention provides two sets of elliptical thick plates each having a concave surface on the bottom surface of one of the elliptical thick plates in which three electron beam passing holes are provided in-line in the major axis direction. In the method of manufacturing an electrode for an electron gun, the main lens electrode A is formed between the opposing electrodes by arranging the concave surfaces facing each other with a distance between the contacts, and the main lens electrode A is made to have approximately the same thickness as the oval thick plate electrode.
Predetermined coining pilot holes are formed in each of the three electron beam passage holes in the plate blank, and then a concave surface of a desired depth is formed on the bottom surface of one of the plate blanks.

In this field, the formation of these four surrounds involves a first coining process in which the entire built-up part of the material is formed around the groove edge at the same time as the preforming of the concave surface, and then a predetermined coining process in which the built-up part is flattened and at the same time and a second coining step to form a concave surface. Thereafter, the outer shape of the oval thick plate electrode is punched out to a predetermined size, and then three electron beam passage holes are punched out to a size of 9 mm.

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings.

Figure 3 (a), (b) to Figure 7 (a), (b)
U M1. for color picture tube according to the present invention. FIGS. 5A and 5B are process diagrams for explaining an example of a method for processing electrodes for Ichi5 subguns related to the method for manufacturing subguns, where FIG. 5A is a plan view and FIG.
The cross-sectional views are shown respectively. First, Figure 3 (a
) l As shown in (b), a thick plate of approximately 2 strips of thickness 10
Coining pilot holes 11 of 7Jr>j2 are formed in each of the three holes J51 corresponding to the beam passage holes.

In this case, these prepared holes 11 reduce the coining force required for concave coining in the next process, and increase the coining force.
! ': The purpose is to form a concave 1f opening with an f degree. Therefore, although the hole shapes of these prepared holes 11 are circular holes in the drawing, they may have other shapes than circular holes. Next, as shown in Figure 4 (a) l (b), the thickness of the thick plate 10
m of approximately the same shape as the predetermined elliptical concave surface on one bottom surface of
At the same time as the preforming coining of the concave surface 12 in the shape of A continuous ■-shaped groove 14 is formed in the built-up part around the elliptical concave surface 12 by a method such as a press mold.Subsequently, the fifth [ti(a)] is formed.

As shown in (b), a second coining process is performed to flatten the built-up portion 13 and at the same time form a predetermined elliptical concave surface 22f. As a result of this, Section 41il(a), (
The radius (R) around the groove edge of the four elliptical surfaces 12 shown in b) can be formed uniformly, and at the same time, the elliptical concave surface 22 with a high sheath degree can be formed. Next, the outer shape of this thick plate material 1o is punched out to fit the dimensions of the ivy foot (7).
) Oval thick plate-shaped electrode 15f shown in FIG. In this way, the electron gun electrode 17 is completed.

〔Effect of the invention〕

As explained above, according to the method of manufacturing an electron gun for a color picture tube according to the present invention, there are problems in electrode processing.
The extremely excellent effect of being able to easily form an electron gun electrode that can fully enlarge the aperture of the main lens and achieve the same focusing characteristics without causing any side effects such as voltage characteristics is achieved (4).

Figure 1 is a sectional view of the main parts showing the structure and operating state of a conventional in-line electron gun, and Figure 2 is a plan view of the main parts showing the conventional upper focusing electroplating.
Figure 3 (a) + (b) Outer ring Figure 7 (a), (b)
) are a plan view and a cross-sectional view of a main part of a process explanation of an embodiment of a method of manufacturing an electron gun for a color picture tube according to the present invention.

10...Thick plate material, 11...Prepared hole, 12...
・Concave surface, 13... Overlay part, 14... ■-shaped groove,
15...Oval J-shaped plate electrode, 16A, 16B, 1
6C---Electron beam passage hole, 11...Electron gun electrode, 22...(i circular concave +h+.

Figure 3 iot lbl +O11b1 101 lb+ Figure 4 011bl +O1lbl

Claims (1)

[Claims] Two sets of oval thick plates with a concave surface on the bottom surface of one of the oval thick plates with three electron beam passage holes in the long axis direction are placed opposite each other with the concave sides facing each other with a gap between them. Color receiver 1 equipped with electron gun electrodes that form the main lens electric field between polarizations!
Kangetsu 111: In the child gun, a step of forming predetermined coining pilot holes in a thick plate material having approximately the same thickness as the oval thick plate electrode at locations corresponding to the three electron beam passage holes, and A first coining pilot hole is formed on one side of the thick plate material to simultaneously form a concave surface of a desired depth and a built-up portion of 4 cm around the tl a second coining step of leveling the plate to form a predetermined concave surface; a step of punching the outer shape of the thick plate to a predetermined size; and a step of punching three electron beam passing holes in the coining pilot hole to a predetermined size. 1. A method for advancing an electron gun for a color picture tube, characterized by comprising the steps of punching.