JPS63232246A - Molding method of electrode for color cathode ray tube electron gun - 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 Industrial Application] The present invention relates to an electrode for an electron gun of an in-line color cathode ray tube (particularly, an electrode for an electron gun having a slit-like recess around the electron beam passage hole). Regarding the electrode group.

[Conventional technology]

Conventionally, an electron gun aimed at improving the focus around the screen of a color cathode ray tube, for example, Japanese Patent Application Laid-Open No. 59-157.
The one shown in Japanese Patent No. 936 is known. This structure is
A slit-shaped recess is provided around the electron beam passage hole of the second grid electrode, and the plate thickness around the hole is made thicker in the vertical deflection direction and thinner in the horizontal deflection direction. The divergence angle is reduced in the vertical deflection direction.

Here, the electrode plate thickness is 0.45 to 1 of the electron beam passage hole.
．． 0 times, and the concave plate thickness is 0.2 to 0 of the electron beam passage hole.
．． It is set to 4 times.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not cause any particular problems in cathode ray tubes with a screen size of less than 20', but for ultra-large tubes with a screen size of 20' or more, for example 33', there is a problem that high-precision focusing characteristics cannot be obtained. there were.

An object of the present invention is to provide an electrode for an electron gun that can provide highly accurate focusing characteristics even in a large tube.

[Means for solving problems]

The above purpose is to set the electrode plate thickness to 0.4 to 0.4 of the electron beam passage hole diameter.
1.0 times, and the concave plate thickness is 0.1 of the electron beam passage hole diameter.
This is achieved by forming a uniform thickness of ~0.2 times.

[Effect]

Since the plate thickness of the recess is 0.1 to 0.2 times the diameter of the electron beam passage hole and the depth of the recess is deep, the divergence angle in the horizontal direction of the electron beam is much larger than the divergence angle in the vertical direction. . This improves focus characteristics even in large tubes.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2f. In the second grid electrode 1, three electron beam passing holes 2 are formed in a straight line.

Further, a slit-shaped recess 3 is formed in the periphery of the electron beam passage hole 2 in the X direction (horizontal deflection direction). Here, if the diameter of the electron beam passage hole 2 is D, the electrode thickness T is (0.4 to 1.0)], and the plate thickness t of the recess 3 is (
0.1-0.2) is set to D.

In this way, the plate thickness t of the recess 3 is very thin (0,1 to 0.2)D, that is, the depth of the recess 3 is deep, so that the horizontal deflection direction (X direction) of the electron beam The divergence angle of
The divergence angle in the vertical deflection direction (X direction) is much smaller than that, and highly accurate focusing characteristics can be obtained.

Next, I will discuss the results of the first prototype. For example, in a cathode ray tube E with a neck diameter of 29 wφ, the second grid electrode 1
The distance S of the three electron beam passing holes 2 is 6°6, the distance D is 0.67 points, 'f' = 0.30 rm (
= 0.45D), t = 0.13 tag (= 0
．． 2D), S = 5.5,...
,,D=0.64 key, '[' = 0.26
tra (= 0.4 D), t = 0.10 m
(=0°15D), very good results were obtained.

The second grid electrode 1 having the deep recess 3 described above can be manufactured, for example, as shown in FIG. 3F.

First, as shown in FIG. 1a), an elliptical surplus relief hole 4 having a major axis in the longitudinal direction E of the slit-like recess is formed in advance. Next, as shown in Figure (b), a slit-like recess 3 is formed by coining. At this time, the escape hole 4 is mainly contracted in the longitudinal direction of the slit-shaped recess 3 due to the coining process, that is, the long diameter side of the escape hole 4.
The escape hole 5 has a shape close to a circle. Next (this figure fe)
As shown in FIG. 1, a predetermined beam passage hole 2 is formed in a portion of the escape hole 5.

Since the escape hole 5 after the coining process has a shape close to a circle, no drilling occurs even when the beam passage hole 2 is formed. In addition, the pre-provided elliptical extra-thickness relief hole 4 should be set within the range in which the beam passage hole 2 can be machined after coining processing, and the hole area should be sufficiently large compared to the circular hole E. This reduces machining force and extends the life of the coining tool.

〔Effect of the invention〕

According to the present invention, the thickness of the senior plate is set to 0.000 mm of the diameter of the electron beam passage hole.
4 to 1.0 times, and the thickness of the recess is 0 of the diameter of the electron beam passage hole.
．． Since it is formed to have a uniform thickness of 1 to 0.2 times, highly accurate focusing characteristics can be obtained even in a large tube.

[Brief explanation of drawings]

FIG. 1 shows the electron beam passing hole portion of the second grid electrode according to Embodiment 1 of the present invention, +a+ is an enlarged front view, and t
b) is a cross-sectional view, FIG. 2 shows the second grid electrode, and
) is a front view, (1)) is a sectional view, and Figure 3 (al to fc
FIG. 1 is a sectional view showing an embodiment of the method for forming the second grid electrode shown in FIGS. 1 and 2; DESCRIPTION OF SYMBOLS 1... Second grid electrode, 2... Electron beam passing hole, 3... Concave portion, D... Electron beam passing hole diameter, 'P... Electrode plate thickness, t... Concave portion plate thickness. Agent Patent Attorney Isamu Ogawa Fig. 1 (CI) ■ (b) Fig. 3 (a) (b) Fig. 2 (a) (b) 1: 2nd Gerrits Rden 1 & 2: Denjin Beam Through hole 3: Concave name β O: Electric) Beam passing Lt 仝 T: Electric ↑ J! 1st grade thickness twice part Subou (C)

Claims (1)

[Claims] 1. In an electrode for an electron gun that has a slit-like recess around the electron beam passage hole, the electrode plate thickness is 0.4 to 1.0 times the electron beam passage hole diameter, and the recess plate thickness is the same as the electron beam passage hole diameter. An electrode for an electron gun, characterized in that it is formed to have a uniform thickness of 0.1 to 0.2 times.