JPH0794086A - Method for assembling electron gun for cathode-ray tube - Google Patents

Abstract

PURPOSE:To facilitate the assembly in a case having a main lens having a large aperture and improve the precision by planting a second anode support metal fitting on an insulating support beam, and fixing it, after fixing a first anode, with the axial centers of the second and first anodes being aligned to each other. CONSTITUTION:An insulating support beam 3 is heated to a softening temperature, a second anode support metal fitting 5 is buried and planted therein in such a manner that the end part has a slight gap G with the inner wall of a second anode. On the other hand, a first anode support metal fitting 4 is welded to the minor diameter part of a first anode 1. The beam 3 in which the metal fitting 5 is planted is heated, and the metal fitting 4 of the anode 1 is buried and fixed therein. Thereafter, the anode 2 is inserted to enclose the outer circumference of the beam 3, and regulated for the axial center with the anode 1 in the gap G, and the inner wall of the anode 2 is welded by laser beam in the state where the both are made concentric to each other. Since the laser beam is emitted from the outside of the anode, the radiated part of the anode 2 is welded to fill the gap G and also fused to the anode 1, so that no external force is added to the anodes 2, 1, and the deformation can be prevented to improve precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun for a cathode ray tube, and more particularly to an assembling method of an electron gun for a cathode ray tube which is capable of high resolution display by forming an electron lens having a maximum aperture in a limited space.

[0002]

2. Description of the Related Art A cathode ray tube for displaying an image is a vacuum envelope comprising a panel portion having a fluorescent surface coated on its inner surface, a neck portion for accommodating an electron gun, and a funnel portion connecting the panel portion and the neck portion. And a deflection yoke mounted on the outer wall of the funnel portion.

The resolution of the cathode ray tube largely depends on the size of the main lens aperture of the electron gun housed in the neck portion. Generally, the larger the diameter of the main lens, the smaller the aberration distortion and the like, and the more the electron beam can be focused. As a result, the resolution on the phosphor screen can be improved.

FIG. 7 is a cross-sectional view for explaining an example of a conventional electron gun for a cathode ray tube in which the diameter of the main lens is increased to achieve a high resolution. 01 is a first anode, 010 is a connecting portion thereof, 02 Is a second anode, 020 is its narrowed portion, 03 is an insulating support rod, 04 is a first anode support fitting, and 05 is a second anode support fitting. In the drawings, the cathode, the control grid electrode, and the accelerating electrode have known configurations and actions, and therefore their explanations are omitted by giving them special reference numerals.

In this figure, the electron gun of this type is provided with a large-diameter second anode 02 including a first anode 01 constituting the main lens in order to increase the diameter of the main lens.
It is configured to form a main lens at the first anode open end in the anode 02.

The first anode 01 and the second anode 02 are fixed together with other electrodes to an insulating support rod 03 made of a glass material via a support fitting.

According to this structure, by making the second anode 02 a diameter close to the inner diameter of the neck portion, the aperture of the main lens can be made large and therefore the resolution of the cathode ray tube can be improved. As a disclosure of the conventional technique, for example, Japanese Patent Publication No. 58-31696 can be cited.

[0008]

In the above-mentioned conventional technique, the distance between the portion forming the main lens and the portion fixing the first anode 01 and the second anode 02 to the insulating support rod is large. There was a problem that the assembling accuracy could not be improved.

That is, as shown in FIG. 7, the first
Both the anode 01 and the second anode 02 have a small diameter portion (throttled portion).
Are supported by the support metal fittings 04,
No. 05 is assembled in such a manner that it is embedded in the insulating support rod at the same time while being fixed to the first anode and the second anode in advance.
In particular, it has been difficult to ensure uniform assembly accuracy in mass production.

An object of the present invention is to solve the above problems of the prior art, to facilitate the assembling of an electron gun for a cathode ray tube equipped with a large-diameter main lens, and to improve the accuracy thereof. To provide a method of assembling.

[0011]

In order to achieve the above object, the present invention requires a cathode, a control grid electrode, an accelerating electrode, a first anode 1, a second anode 2, etc., as shown in FIG. In an assembling method of an electron gun for a cathode ray tube in which electrodes are insulated and supported by an insulating support rod 3 in a predetermined order and an electrode interval, a first anode supporting metal member 4 protruding outward is provided on an outer peripheral portion of the first anode 1. A second anode support fitting 5 for fixing and supporting the second anode 2 so as to form a slight gap with the inner wall of the second anode 2.
The first anode support metal fitting 4 is embedded in the insulating support rod 3 in which the first anode support metal fitting 5 is embedded on the back side of the second anode support metal fitting 5, and then the first anode is fixed by the gap G of the second anode support metal fitting 5. The second anode support fitting and the second anode 2 so that the axial center with respect to 1 is adjusted and the gap is filled with the melted metal material.
Is welded to fix the first anode 1 and the second anode 2 concentrically.

[0012]

As described above, the insulating support rod 3 is heated to the softening temperature, the second anode support fitting 5 is embedded, and the end portion thereof is planted so as to have a slight gap G from the inner wall of the second anode. ((A) of FIG. 1).

On the other hand, the first anode support fitting 4 is welded to the small diameter portion of the first anode 1 ((b) of FIG. 1).

Next, the insulating support rod 3 in which the second anode support fitting 5 is implanted is heated in the same manner as above, and the support fitting 4 of the first anode 1 is embedded and fixed (FIG. 1 (c)). .

After that, the second anode 2 is inserted so as to surround the outer circumference of the insulating support rod, the axial center of the first anode 1 is adjusted at a gap G, and the inner wall of the second anode 2 is made concentric with the two. The second anode support fitting 5 is welded with laser light or the like. At this time,
Since the laser light is emitted from the outside of the second anode, the irradiated portion of the second anode is melted to fill the gap G and be welded to the first anode. No external force is applied and it does not deform.

In this way, after the support metal fitting 5 of the second anode 2 is previously implanted in the insulating support rod 3 and the first anode 1 is fixed,
Since the axis of the second anode 2 is fixed by matching the axis of the first anode 1 with the axis of the first anode 1, the axes of the first anode 1 and the second anode 2 can be easily aligned with each other with high accuracy. The main lens electrode can be configured.

Further, since the support portions of the first anode 1 and the second anode 2 and the main lens forming portion are not largely separated from each other as in the conventional case, the displacement of the electrodes due to vibration or the like does not occur.

Therefore, the cathode ray tube equipped with the electron gun assembled according to the present invention can display a high-resolution image with the large-diameter main lens.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 is an explanatory view of an embodiment of the electron gun for a cathode ray tube assembled by the method for assembling an electron gun for a cathode ray tube according to the present invention, in which the same reference numerals as those in FIG. 1 correspond to the same parts.
6 is an electrode adjacent to the cathode side, and 7 is a neck of the cathode ray tube.

FIG. 3 is a front view seen from the direction of arrow A in FIG. The neck 7 is not shown here.

In FIGS. 2 and 3, the second part before assembling is shown.
The distance between the anode support fitting 5 and the second anode 2 is 0.2 mm.
And is assembled concentrically with the first anode at this interval during welding.

The second anode 2 has a cylindrical shape formed of a plate body having a thickness of 0.4 mm, and the axial center can be easily adjusted at the time of assembly at the above intervals.

The first anode support fitting 4 and the second anode support fitting 5 are both U-shaped in cross section, and the tips thereof are embedded in the insulating support rod 3 so that the first anode 1 and the second anode 2, The other electrodes are fixed to form an electron gun.

With the above structure, the second anode 2 can be an electrode having a diameter close to the inner diameter of the neck 7,
A large-diameter main lens is formed in the open portion of the first anode 1 in the second anode 2.

Therefore, the resolution of the cathode ray tube equipped with the electron gun of the above embodiment is greatly improved.

4A and 4B are explanatory views of another embodiment of the electron gun for a cathode ray tube assembled by the method of assembling the electron gun for a cathode ray tube according to the present invention, wherein FIG. 4A is a sectional view of a main part and FIG. It is a perspective view of an anode support metal fitting.

In the figure, 5'is a second anode support fitting,
Reference numeral 5 "corresponds to the tongue portion, and the same reference numerals as those in the above embodiment correspond to the same portions.

In this embodiment, a second anode support fitting 5'pre-installed on the insulating support rod 3 is provided with a tongue portion 5 "extending from the insulating support rod 3 toward the second anode 2 and the tongue portion is formed. The height of the upper surface of 5 ″ and the inner wall of the second anode 2 are assembled with the same spacing as in the above embodiment.

According to this embodiment, the diameter of the small diameter portion of the first anode 1 can be increased, and the diameters of the other electrodes can be increased.

FIG. 5 is an explanatory view of still another embodiment of the electron gun for a cathode ray tube assembled by the method for assembling an electron gun for a cathode ray tube according to the present invention, wherein the same reference numerals as those in the above embodiment correspond to the same parts and components. Reference numeral 21 is a second half of the second anode, and 22 is a second half of the second anode.

In this embodiment, the second anode 2 in the embodiment described with reference to FIG.
The relative positional accuracy with respect to the anode 1 is further improved.

That is, the second anode 2 is the second anode front half portion 2.
1 and the second anode second half 22. First, the second anode first half 21 is fixed to the insulating support rod 3 in the same manner as in FIG. 4, and then the second anode second half 22 is fixed to the second anode first half. Part 2
It is welded to No. 1.

According to this embodiment, from the second anode 2 to the first
Since the fixing work can be performed with the anode 1 exposed, the work of aligning the axes of the both becomes easy.

The electron gun according to each of the above embodiments can be applied to a cathode ray tube using a plurality of electron beams such as a shadow mask type color cathode ray tube, but is particularly suitable for a single electron beam type cathode ray tube.

For example, a single electron beam type cathode ray tube such as a cathode ray tube used in a projection type image display apparatus, a so-called projection type cathode ray tube, is capable of obtaining an electron beam having a relatively large current value without distortion so as to obtain a required resolution. For focusing, it is necessary to have an electron lens in the neck of limited inner diameter with the largest real aperture possible.

FIG. 6 is a partial sectional view for explaining a structural example of a projection type cathode ray tube equipped with an electron gun assembled according to the present invention, in which 80 is a projection type cathode ray tube, 81 is a glass bulb, and 82.
Is a neck portion 82, 83 is an electron gun, 84 is a panel portion, 85
Is a fluorescent screen, 86 is a deflection yoke, 87 is a convergence yoke, 88 is a centering magnet, 89 is an electrostatic lens, 91 is a beam alignment magnet, and 94 is an electron beam.

As described above, by adopting the electrostatic lens as described above in the projection type cathode ray tube, it is possible to obtain good focus characteristics from a small current region to a large current region. That is, the resolution can be improved without reducing the brightness.

[0039]

As described above, according to the present invention,
The axes of the first anode and the second anode can be easily aligned with each other, and a highly accurate main lens electrode can be constructed.

Further, since the supporting portions for the first and second anodes and the main lens forming portion are not largely separated from each other as in the conventional case, the displacement of the electrode position due to vibration or the like does not occur.

Therefore, the cathode ray tube provided with the electron gun assembled according to the present invention can display a high-resolution image with the large-diameter main lens.

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of an electron gun assembly method according to the present invention.

FIG. 2 is an explanatory view of one embodiment of an electron gun for a cathode ray tube assembled by the method for assembling an electron gun for a cathode ray tube according to the present invention.

FIG. 3 is a front view seen from the direction of arrow A in FIG.

FIG. 4 is an explanatory view of another embodiment of the electron gun for a cathode ray tube assembled by the method for assembling the electron gun for a cathode ray tube according to the present invention.

FIG. 5 is an explanatory view of still another embodiment of the electron gun for a cathode ray tube assembled by the method for assembling the electron gun for a cathode ray tube according to the present invention.

FIG. 6 is a partial cross-sectional view illustrating a structural example of a projection-type cathode ray tube including an electron gun assembled according to the present invention.

FIG. 7 is a cross-sectional view illustrating an example of a conventional electron gun for a cathode ray tube in which the aperture of a main lens is increased to achieve high resolution.

[Explanation of symbols]

 1 1st anode 2 2nd anode 3 Insulating support rod 4 1st anode support metal fitting 5 2nd anode support metal fitting.

Claims (1)

[Claims] 1. A method for assembling an electron gun for a cathode ray tube, wherein required electrodes such as a cathode, a control grid electrode, an accelerating electrode, a first anode and a second anode are insulated and supported by an insulating support rod in a predetermined order and at an electrode interval. A second anode support fitting that fixes the first anode support fitting projecting outward to the outer periphery of the first anode and supports the second anode so as to form a slight gap with the inner wall of the second anode. The first anode support fitting is embedded in the insulating support rod in which the first anode support fitting is embedded on the back side of the second anode support fitting, and thereafter, the axis of the first anode is fitted by the gap of the second anode support fitting. The inner periphery of the second anode support fitting and the second anode is welded so that the gap is filled with the melted metal material, and the first anode and the second anode are fixed concentrically. Method for assembling electron gun for cathode ray tube.