JPS59165344A - Electron gun for cathode ray tube - Google Patents

Abstract

PURPOSE:To simplify the manufacturing process and to enable provision of an electron gun of high quality in a short period of time, by producing a thick plate member with holes by application of punching in the same direction to form the periphery of the member and the holes, i.e., those for the electron beams to pass through. CONSTITUTION:In producing a thick plate member with holes 17d, 18a, first, the member without holes is punched out from a material of predetermined thickness applying the punching in the direction as shown by the arrow 311, 312, namely in the direction away from the main lens. Then, the hole portions 11 for the electron beams to pass through are punched by application of the punching in the same diretion as indicated by the arrow 32, i.e., away from the main lens, with the surface 33 not including the portion where burr 33a is formed by the above first punching taken as the base surface. Thus, the burr 33a produced at the punching of the periphery and the burr 33b produced at the punching of the holes 11 for the electron beams to pass through are adapted to be on the same end, the end to be supported by a dish shaped member with holes in the succeeding process, and because of it, there are formed curved surfaces 34a, 34b of the substantially same curvature on the end to face the main lens. Then, by substantially removing the burrs 33a and 33b by a short period of time of tumbling, the 5th electrode comprising 17b, 17c, and 17d and the 6th electrode comprising 18a and 18b can be provided.

Description

[Detailed Description of the Invention] [Technical Background of the Invention] The present invention relates to an electron gun for a cathode ray tube. The present invention relates to a cathode ray tube electron gun using the member.

[Technical background of the invention and its problems]

The electron gun installed in a color picture tube, which is a type of cathode ray tube, is a so-called unitized in-line electron gun, which has each electrode that makes up the electron gun integrally formed and has a row of electron beam passage holes. Guns have become mainstream.

On the other hand, the diameter of the neck inside the electron gun is gradually becoming narrower as a measure to save energy in deflection power.

When a 22ized in-line electron gun is installed inside such a narrow neck, the problem is the diameter of the electron beam passage hole in the opposing electrode that forms the main lens. If the outer diameter and electron beam passage hole are formed by press molding from a thin plate, the diameter of the main lens will be small, resulting in poor convergence as an electron gun, and the contrast and brightness of the reproduced image drawn on the phosphor screen will be poor. - As a countermeasure to this problem, in order to make the main lens as large as possible, the part of the electrode group that forms the main lens, especially near the main lens, is thickened, for example by pressing a one-piece member, so that its outer diameter and the electron beam can be reduced. A technique has been developed to prevent the distortion of the electric field that forms each electron lens by forming a passage hole and making the diameter of the electron beam passage hole as large as possible and 11 in diameter.

Next, an example of an electron gun using an electrode element formed from such a thick member will be explained with reference to FIG.

That is, the electron gun (1) has a cathode (2) containing a heater, a first electrode (3), a second electrode (4), a third electrode (5), and a fourth electrode.
It has a structure in which the electrode (6), the fifth electrode (7), and the sixth electrode (81) are implanted in the insulating support rod (91) at predetermined intervals, and the second electrode (4) and the fourth electrode Connect (6),
By applying a voltage of several hundred volts, connecting the third electrode (5) and the fifth grid (7) and applying a voltage of several thousand volts, and applying an anode voltage to the sixth electrode (81), the third electrode (81) is connected. (5), the fourth electrode (6), and the seventh electrode form an auxiliary lens, and the 511th electrode (7) and the sixth electrode (8) form a pi-potential type main lens.

In such an electron gun (1), for example, the fifth electrode (7) is composed of three dish-shaped hole electrode elements (7a), (7b), (7c), and (7).
d) and a thick-walled perforated plate-like member (7d) supported by the open end edge of this electrode element (7d), and the sixth electrode (8) consists of the thick-walled perforated plate-like member (8a) and this Thick-walled perforated plate member (8
a) and a dish-shaped perforated electrode (8b) supporting the electrode at its open end.

These thick-walled perforated plate-like members (7d) (8a) have three electron beam passage holes (nR
) (nG) (IIB) are bored by a press or the like, but depending on the method of formation, the wall (12t) between the electron beam passing holes (IIR) (IIG) (IIB)
By forming (12t) extremely thin, it is possible to form a large main lens, and the electric field distributions formed near the electron beam passage holes (IIR) (IIG) (IIB) interfere with each other. Therefore, it is possible to obtain a high-quality electron gun having a large-diameter main lens.

However, in the conventional manufacturing method of these thick-walled perforated plate-like members (7d) (8a), a material of a predetermined thickness is first
(21t) direction, then electron beam passing hole I
A method of punching out in the arrow (26 directions) is used.
This is because it is difficult to punch out the next electron beam passage hole I. Therefore, burrs (23a) (23b') are formed in the opposite direction, and corner curved surfaces (24a) (24b) are formed.
This burr (231L) (
15 to remove 23b') and form a corner curved surface.
After performing tumpling for ~20 hours, as shown in Fig. 4, the burrs (23a) (Z3b) were removed and the corner curved surfaces (25a) (25b) with R = 0.3 or more necessary to form the main lens were formed. This is the current situation.

However, in such a method, the thick perforated plate member (7d) (8
Particularly in the manufacturing process of a), the tampling becomes long and the curvature of the corner curved surface (25&) ($b) also differs.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide an electron gun for a cathode ray tube, which has good characteristics and can form a thick-walled perforated plate-like member in a single time with good quality.

[Summary of the invention]

The present invention comprises at least a plurality of electrodes including an electrode group forming a main lens for converging an electron beam onto a phosphor screen, and an insulating support rod supporting these plural electrodes to form a main electron lens. In an electron gun for a cathode ray tube, at least one electrode is composed of a thick-walled perforated plate-like member and a dish-like perforated support member that supports the thick-walled perforated plate-like member at an open end edge. An electron gun for a cathode ray tube, characterized in that the outer shape of the perforated plate-like member and the punching direction of the hole are both from the main lens side toward the dish-like perforated support member,
In this embodiment, the cathode ray tube is a color picture tube, and the electron gun is an in-line electron gun that emits a plurality of electron beams arranged in a row.

[Embodiments of the invention]

Since the cathode ray tube electron gun is almost the same as that shown in FIG. 1, drawings and explanations are omitted, and the same reference numerals indicate the same parts.

That is, in this example, thick-walled perforated plate-like members (17d) (18
As shown in FIG.
), electron beam passage hole aυ
Similarly, the burr (33a) when punching out the outer diameter from the direction of the arrow (to), that is, the direction of the main lens, and the burr (33a) when punching the first beam passage hole aυ! By providing the ribs (33b) in the same direction, that is, in the direction in which they will be supported by the dish-shaped perforated support member in a subsequent process, curved surfaces (34B) (34b) having approximately the same radius are formed on the main lens side. Next, as shown in Figure 6, by tamping for a short time, the burr (33a
) (33b) is almost removed, and as shown in FIG. In such a cathode ray tube electron gun, a thick perforated plate member (17d) (1
Since the outer diameter of 8a) and the hole I, which is the electron beam passing hole, are punched out in the same direction as the main lens formation direction, a curved surface of R=0.3 or more is inevitably formed on the main lens side. Also, the burrs (33a) (&3b) can be easily removed with a short tampling process, eliminating the need for the conventional process of removing the burrs and forming a curved surface of 0.3b or more. Therefore, an electron gun assembly with good quality can be assembled in a short time.

Although the above-mentioned embodiments mainly relate to a unitized in-line type electron gun for a color picture tube, the invention is not limited thereto, and the thickness of the thick-walled perforated plate member may be thicker or thinner than, for example, 111II. Of course, the same is true.

〔Effect of the invention〕

The present invention is constructed by a simple method of punching out the outer diameter of a thick-walled perforated plate member and the hole portion, that is, the electron beam passage hole portion, from the same direction, so that the process is simple and high quality can be achieved in a short time. It is possible to obtain an electron gun for a cathode ray tube,
Its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is an explanatory side view showing an example of an electron gun for an electron tube, FIG. 2 is a perspective view showing the thick-walled perforated plate member of FIG. 1, and FIGS. 3 and 4 are conventional thick-walled perforated plate members. 3 is a cross-sectional view showing the outer diameter and the electron beam passage hole after punching, FIG. 4 is a cross-sectional view showing the state after tampling, and FIG. 5 to 7 are diagrams showing an embodiment of the electron gun for cathode ray tubes of the present invention, and FIG. FIG. 6 is a cross-sectional view showing the state after short-time tampling, and FIG. 7 is a cross-sectional view of the main part of the cathode ray tube electron gun. 7...Fifth grid 7a% 7b% 7Ct 8b,... dish-shaped electrode element 7
L8a... Perforated plate-shaped electrode member 8... Sixth grid 9... Insulating support rod 11111R111G, IIB... Electron beam passage hole portion 211.21! , 311.31. ...Outer diameter punching direction 22.32...Electron beam passing hole punching direction 13a %23b 133a, :(3b...
Return 24a, 24b% 25&, 25b, 34&
, 34b...Curved surface attorney Patent attorney Inoue-O Figure 1 Figure 2

Claims (1)

[Claims] (1) a plurality of electrodes including an electrode group forming a main lens for focusing an electron beam onto a phosphor screen;
an insulating support rod supporting the plurality of electrodes, and at least one electrode forming the main electron lens has a thick-walled perforated plate-like member and an open end of the thick-walled perforated plate-like member. In a cathode ray tube electron gun comprising a dish-shaped perforated support member supported at an edge, the outer shape of the thick-walled perforated plate-like member and the punching direction of the hole are both from the main lens side to the dish-shaped perforated support member. An electron gun for cathode ray tubes, characterized in that it is made in the direction of 12) An electron gun for a cathode ray tube according to claim 1, wherein the cathode ray tube is a color picture tube, and the electron gun is an in-line electron gun that emits a plurality of electron beams arranged in a row. .