JPH117904A - Electron gun assembly for cathode ray tube - Google Patents

Abstract

(57) Abstract: A high-performance electron gun for a cathode ray tube, which facilitates the assembling work of an electron gun in which a plate-like electrode is inserted into a cup-shaped electrode and improves the accuracy of an electrode of an assembled main lens. Provide a structure. An outer diameter of a plate-shaped electrode is made smaller than an inner diameter of a cup-shaped electrode, and a protruding portion is formed inside an inner wall of the cup-shaped electrode to which the plate-shaped electrode is inserted and welded. By welding the plate-shaped electrode 17a to the protruding portion 17c, the plate-shaped electrode 17a can be easily inserted into the cup-shaped electrode 17, and the plate-shaped electrode 17a is installed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun assembly for a cathode ray tube, and more particularly, to a cathode ray tube having an improved accuracy by improving an electrode structure of a main lens portion of an in-line type electron gun mounted on a shadow mask type color cathode ray tube. The present invention relates to a tube electron gun assembly.

[0002]

2. Description of the Related Art A color cathode ray tube such as a color picture tube or a display tube is widely used as a monitor for television broadcast reception or information processing equipment because of its fine image reproducibility.

A color cathode ray tube of this type contains a funnel having a face plate having a phosphor screen formed on an inner surface thereof, and an electron gun assembly connected to the funnel and emitting an electron beam toward the phosphor screen. A vacuum envelope having at least a neck.

FIG. 7 is a schematic cross-sectional view for explaining the configuration of a shadow mask type color cathode ray tube as an example of a color cathode ray tube to which the present invention is applied. Reference numeral 20 denotes a face plate, 21 denotes a neck, and 22 denotes a face plate. A funnel 23 connected to the neck; a phosphor screen 23 formed on the inner surface of the face plate to form a video display surface;
4 is a shadow mask as a color selection electrode, 25 is a mask frame that holds the shadow mask and forms a shadow mask structure, 26 is an inner shield that shields external magnetism, and 27 is the shadow mask structure planted on the inner wall of the face plate. A suspension spring mechanism for suspending and supporting a standing stud, 28 is housed in a neck and accommodates three electron beams Bs
(× 2), an electron gun that emits Bc, 29 is a deflecting device that deflects the electron beam horizontally and vertically, 30 is a magnetic device that performs color purity and centering correction, 31 is a getter, 3
2 is an internal conductive film, and 33 is an explosion-proof band.

In the configuration shown in FIG.
0, a neck 21 and a funnel 22 constitute a vacuum envelope, and three electron beams Bc and Bs × 2 emitted from the electron gun 28 in a horizontal line (inline) are used by a deflection device 29 to form a deflection magnetic field. To deflect in two directions, horizontal and vertical, to scan the phosphor screen 23 two-dimensionally.

The three electron beams Bs and Bc × 2 are red (side beam Bs) and green (center beam Bs), respectively.
c) modulated by color signals of blue (side beam Bs), red, green, and red constituting the phosphor screen 23 by receiving a color selection through a beam passage hole of a shadow mask 24 disposed immediately before the phosphor screen 23; A desired color image is reproduced by projecting on each of the three blue phosphor mosaics.

FIG. 8 is a side view of an essential part for explaining an example of the configuration of an in-line type electron gun used in the color cathode ray tube shown in FIG. 7, wherein 10 is a cathode and 11 is a first grid which is a control electrode. Electrode, 12 is the second grid electrode, 13 is the third grid electrode
Grid electrode, 14 is a fourth grid electrode, 15 is a fifth grid electrode, 16 is a sixth grid electrode, 16a is a plate-shaped correction electrode of the sixth grid electrode, 17 is an anode, 17a is a plate-shaped correction electrode of an anode, 18 Is a shield cup and 19 is an insulating support.

In this electron gun, three electron beams generated at a triode comprising a cathode 10, a first grid electrode 11 and a second grid electrode 12 are applied to a third grid electrode 13 and a fourth grid electrode 14. And the fifth grid electrode 15 accelerates and converges on the previous stage and the sixth grid electrode 1
The required convergence is achieved by the main lens formed on the surface facing the anode 6 and the anode 17, and the light is directed to the phosphor screen of FIG.

In this type of electron gun, the electrodes (the fifth grid electrode, the sixth grid electrode 16, and the anode 17) constituting the focusing lens and the main lens are cup-shaped electrodes, and in particular, the sixth electrode constituting the main lens. The grid electrode 16 and the anode 17 each have a single opening having a rim bent inward at the opposing edges thereof, and a plate-like opening having an opening for each electron beam at a position assembled from the opposing edges. Correction electrodes 16a and 17a are provided.

FIGS. 9A and 9B are schematic sectional views for explaining a main lens forming electrode of an electron gun of the type described above, wherein FIG. 9A is a sectional view in a direction parallel to the in-line direction, and FIG. It is sectional drawing of a perpendicular direction.

In FIG. 1, the end face of the sixth grid electrode 16 facing the anode 17 has a single opening 16-1 having a rim bent inward at a distance of H in the tube axis direction. plate correction electrode 16a having three electron beam passage apertures corresponding to the number of electron beams inside a position retracted by the distance d ₁ with respect to the anode 17 is installed from.

Similarly, the sixth grid electrode 16 of the anode 17
And a single opening 17-1 having an inwardly bent rim at an end face opposed to the gap g.
Plate correction electrode 17a having three electron beam passage apertures corresponding to the number of electron beams inside a retracted position with respect to the grid electrode 16 by a distance d ₂ is installed. The electron beam on the side of the plate-like correction electrode 17a forms an electron beam passage opening together with the inner wall of the cup-shaped electrode of the anode 17.

The single apertures 16-1 and 17-1 and the plate-like correction electrodes 16a and 17a form a substantially large-diameter main lens.

As described above, a pair of electrodes constituting the main lens have an oblong peripheral rim on each of the opposing surfaces, and a plate-like shape is provided inside each of the electrodes at a position retracted from the opposing surfaces. Japanese Patent Laying-Open No. 4-43532 discloses an arrangement in which correction electrodes are arranged to form an effective large-diameter main lens.

[0015]

FIG. 10 is a schematic cross-sectional view illustrating the shape of the main lens forming electrode of the above-mentioned conventional electron gun. FIG. FIG. 2B is a sectional view similar to FIG. 2B, FIG. 2B is a front view of a plate-like electrode 17a welded and fixed inside the cup-shaped electrode, and FIG. 1C is an enlarged view of a main part of FIG.

As shown in FIG.
a is inserted from the open end A side of the cup-shaped anode 17 on opposite edges direction rim is formed along the inner wall B, it is fixed by laser welding or the like edge at the position of the retraction amount d ₂ described above . The plate-like electrode 17a has an electron beam passage opening 17ac through which a central electron beam passes as shown in FIG. 2B, and has electron beam passage openings 17as on both sides thereof for passing the electron beam. Have. The electron beam passage opening 17as on this side forms an electron beam passage opening together with the inner wall of the anode 17.

A recess 17b is formed at the edge of the plate-shaped electrode 17a in contact with the inner wall of the anode 17 at the time of press working, so that when the electrode 17a is inserted into the anode 17, the amount of sliding contact with the inner wall B is reduced. It is reduced to ensure the ease of assembly work.

However, when the concave portion 17b is press-formed on the plate-like electrode 17a, a so-called burr 17d is formed as shown in FIG. If the projection amount L 'of the burr 17d is greater than the tolerance that can pass between the opposing inner walls of the anode 17, the anode 17 and the plate electrode 17a are deformed. In addition, not only burrs but also variations in the outer diameter of the plate-like electrode 17a and the inner diameter of the opening of the cup-shaped electrode 17 cause variations in the cup-shaped electrode 17a.
The insertability of the plate electrode 17a into the plate electrode 17a changes, or the most important inner diameter of the cup-shaped electrode after assembly and the hole diameter of the plate electrode change depending on the laser welding conditions. For this reason, there has been a problem that the characteristics of the electron gun are deteriorated, such as the accuracy of the main lens electrode is reduced and astigmatism is increased, so that a cathode ray tube having required performance cannot be obtained.

Then, there is a problem that it is extremely difficult to correct the installation position of the plate-like correction electrode after assembling and welding.

The sixth grid electrode 16 and its plate-like electrode 1
6a, the description is omitted.

An object of the present invention is to provide a high-performance electron gun assembly for a cathode ray tube, which solves the above-mentioned problems of the prior art, facilitates the assembling work, and improves the accuracy of the electrodes of the assembled main lens. is there.

[0022]

In order to achieve the above object, the present invention provides a cup-shaped electrode in which the outer diameter of the plate electrode is smaller than the inner diameter of the cup electrode, and the plate electrode is inserted and welded. A protruding portion is formed inside the inner wall of the electrode, and the plate-shaped electrode is welded to this protruding portion, so that the plate-shaped electrode can be easily inserted into the cup-shaped electrode, and the plate-shaped correction electrode is accurately set. It was made possible.

The protruding portion is a protruding piece obtained by cutting a part of the wall surface of the cup-shaped electrode inward, or a protrusion extruding a part of the wall surface of the cup-shaped electrode inward.

The direction in which the protruding piece is cut and raised may be either a direction parallel to the tube axis or a direction perpendicular to the tube axis.

According to the above configuration, the amount of retreat of the plate-shaped correction electrode from the opposing surface of the cup-shaped electrode forming the main lens can be precisely set, and the installation plane can be installed in parallel with the opposing surface. An electron gun structure for a cathode ray tube capable of displaying a high-quality image can be provided.

[0026]

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

FIG. 1 is a schematic sectional view for explaining a first embodiment of an electron gun structure for a cathode ray tube according to the present invention.
(A) is a sectional view in a direction perpendicular to the in-line direction, (b)
3 is an enlarged view of a main part of FIG.

In the figure, the same reference numerals as those in FIG. 9 correspond to the same functional parts, and reference numeral 17c denotes a projecting piece. Although FIG. 2 shows the configuration of the welded portion of the plate electrode 17a inserted into the anode 17, the plate electrode 16a inserted into the sixth grid electrode 16 is shown.
Also, a has the same protruding piece as that formed on the anode 17 except that its shape has three electron beam passage holes.

In the figure, the end surface of the surface of the sixth grid electrode 16 facing the anode 17 is bent inward to form a rim, and the end surface of the surface of the anode 17 facing the sixth grid electrode 16 is similarly formed. A rim is formed and both single openings 16-
1 and 17-1 face each other, and a main lens is formed at the facing portion.

As described with reference to FIG. 9, a plate-like electrode 16a is provided inside the sixth grid electrode 16 with a predetermined retreat amount from a portion facing the anode 17.
The plate-like electrode 17a is provided inside the inside of the device with a predetermined retreat amount from a portion facing the sixth electrode 16.

On the wall surface of the anode 17 which is a cup-shaped electrode in the inline direction, a protruding piece 17c cut and raised inward in the tube axis direction by press is formed. This projection 17c
Are formed on each of two parallel sides of the plate-like electrode 17a as described later.

The plate-shaped electrode provided on the cup-shaped electrode has the following shape. That is, taking the anode 17 and its plate-shaped electrode 17a as an example, the plate-shaped electrode 17a provided in the anode 17 has a recessed portion 17b for allowing easy insertion into the cup-shaped electrode. The outer diameter is slightly smaller than the inner diameter of the anode 17 to facilitate charging during assembly.

The plate-like electrode 17a is inserted into a position facing the protruding piece 17c formed on the inner wall of the anode 17, and is fixed by welding with a laser or the like.

FIG. 2 is a front view showing the configuration of a cup-shaped electrode and a plate-shaped electrode inserted therein. FIG.
It is a front view which shows the structure of the anode seen from the grid electrode side, (b) is a front view which shows the structure of the 6th grid electrode seen from the anode side.

In FIG. 2A, a plate-like electrode 17a housed in an anode 17 has an electron beam passage opening 1 in the center.
7ac and a side electron beam passage opening 17as, and a recess 17b is formed in a vertical position (the center of the electrode) of the center electron beam passage opening 17ac. ) Is welded to a protruding piece 17 c formed on the inner wall of the anode 17.

Similarly, the plate-like electrode 16a housed in the sixth grid electrode 16 also has a center electron beam passage opening 16ac and a side electron beam passage opening 16as as shown in FIG. A concave portion 1 in the vertical position of the electron beam passage opening portion 16ac at the center (the center portion of the electrode).
6b, and a side parallel to the electron beam arrangement direction (in-line direction) is welded to a protruding piece 16c formed on the inner wall of the sixth grid electrode 16.

FIG. 3 is a plan view for explaining an example of the shape of the plate-shaped electrode of this embodiment installed inside the cup-shaped electrode. 17a
Is described as an example. FIG. 4 is an enlarged plan view of a main part of FIG.

In FIGS. 3 and 4, the edge of the plate-like electrode 17 parallel to the in-line direction is
Is formed. Projection piece 17c formed on the inner wall of anode 17
The protrusion amount of the recess 17 as shown in FIG.
In order to clear the height L 'of the burr 17d formed at the time of the press working of b, the distance L from the opening end of the recess 17b is formed such that L'≤L.

Thus, when inserting the plate electrode 17a along the inner wall of the anode 17, the burr 17d presses against the inner wall of the anode to prevent the deformation of the anode 17 or the plate electrode 17a.

Similarly, the sixth grid electrode 16 and its plate electrode 16a are prevented from being deformed or deformed. The plate-like electrode 16a
Is formed so that one edge in a direction perpendicular to the in-line direction is slightly smaller than the inner diameter of the sixth grid electrode 16.

According to the above-described embodiment, it is possible to provide a high-performance electron gun assembly for a cathode ray tube in which the accuracy of the electrode of the main lens is improved.

FIG. 5 is a schematic sectional view for explaining a second embodiment of the electron gun assembly for a cathode ray tube according to the present invention.
(A) is a sectional view in a direction perpendicular to the in-line direction, (b)
3 is an enlarged view of a main part of FIG.

In the figure, the same reference numerals as those in FIG. 1 correspond to the same functional portions, and 17c 'is a protruding piece. In the same figure, the configuration of the welded portion of the plate-like electrode 17a inserted into the anode 17 is also shown, but the plate-like electrode 16a inserted into the sixth grid electrode 16 also has three electron beam passing shapes. It has the same protruding piece as that formed on the anode 17 except that it has holes.

The protruding portion formed on the inner wall of the cup-shaped electrode in this embodiment is a protruding piece 17c 'cut and raised in a direction perpendicular to the tube axis.
Is fixed by laser welding. Other configurations are the same as in the first embodiment.

According to this embodiment, it is also possible to provide a high-performance electron gun assembly for a cathode ray tube in which the precision of the electrodes of the main lens is improved.

FIG. 6 is a schematic sectional view for explaining a third embodiment of the electron gun assembly for a cathode ray tube according to the present invention.
(A) is a sectional view in a direction perpendicular to the in-line direction, (b)
3 is an enlarged view of a main part of FIG.

1, the same reference numerals as those in FIG. 1 correspond to the same functional portions, and 17c ″ is a projection. In the same figure, the configuration of the welded portion of the plate-like electrode 17a inserted into the anode 17 is also shown. However, the plate-like electrode 16a inserted into the sixth grid electrode 16 also has the same protrusion 16c ″ as that formed on the anode 17, except that the plate-like electrode 16a has three electron beam passage holes. It has.

The projection formed on the inner wall of the cup-shaped electrode in this embodiment is a projection 17c "cut and raised in a direction perpendicular to the tube axis, and the projection 17c"
Is fixed by laser welding. Other configurations are the same as those of the first and second embodiments.

According to this embodiment, it is also possible to provide a high-performance electron gun assembly for a cathode ray tube in which the accuracy of the electrodes of the main lens is improved.

The present invention can be applied not only to the above-mentioned main lens forming electrode but also to various kinds of electron gun electrodes having similar internal electrodes.

[0051]

As described above, according to the present invention,
It is easy to assemble the above-mentioned plate-shaped electrode in an electrode in which a plate-shaped correction electrode (plate-shaped electrode) is inserted and fixed inside the cup-shaped electrode, and the installation position of the plate-shaped correction electrode is specified with high precision. This makes it possible to provide a cathode ray tube electron gun assembly with high image quality.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view for explaining a first embodiment of an electron gun structure for a cathode ray tube according to the present invention.

FIG. 2 is a front view showing a configuration of a cup-shaped electrode and a plate-shaped electrode inserted therein.

FIG. 3 is a plan view for explaining in detail a shape of a plate-shaped electrode of the present embodiment installed inside a cup-shaped electrode.

FIG. 4 is an enlarged plan view of a main part of FIG. 3;

FIG. 5 is a schematic sectional view for explaining a second embodiment of the electron gun assembly for a cathode ray tube according to the present invention.

FIG. 6 is a schematic sectional view for explaining a third embodiment of the electron gun assembly for a cathode ray tube according to the present invention.

FIG. 7 is a schematic cross-sectional view illustrating the configuration of a shadow mask type color cathode ray tube as an example of a color cathode ray tube to which the present invention is applied.

8 is a main part side view for explaining a configuration example of an in-line type electron gun structure used for the color cathode ray tube shown in FIG. 7;

9 is a schematic cross-sectional view for explaining a main lens forming electrode of the electron gun shown in FIG.

FIG. 10 is a schematic sectional view illustrating the shape of a main lens forming electrode of a conventional electron gun.

[Explanation of symbols]

 16 Sixth grid electrode 16a Plate electrode provided on sixth grid electrode 16b Depressions 16c, 16c 'protruding piece 16c "of sixth grid electrode Projection 17 Anode 17a Plate electrode 17a provided on anode 17b Plate electrode 17a Depressions 17c, 17c 'of projection 17c "projection 17d Burr.

Claims (3)

[Claims] 1. A plurality of cathodes for emitting a plurality of electron beams arranged in a row, a control electrode having a plurality of electron beam passage holes formed in at least a row and opposed to the cathode, and An electron gun structure for a cathode ray tube in which a plurality of electrodes including an accelerating electrode and a cup-shaped focusing electrode and an anode arranged in order from the electrode side to the phosphor screen side are fixed to an insulating support at regular intervals in the tube axis direction. In the plurality of electrodes, the cup-shaped focusing electrode forming the main lens and the cup-shaped electrode constituting the anode have a single opening having a rim bent inward at the opposing end faces of the cup-shaped electrodes and from the end face. A plate-like electrode having an electron beam passage opening for passing an electron beam at a position retracted from each other and having an outer edge welded to the inner wall of the cup-like electrode is provided, and the outer diameter of the plate-like electrode is reduced. As smaller than the inner diameter of the serial cup-shaped electrode has a protruding portion inwardly of the cup-shaped electrode, cathode-ray tube electron gun assembly characterized by comprising by welding the plate-shaped electrode to the protruding portion. 2. An electron gun assembly for a cathode ray tube according to claim 1, wherein said projecting portion is a projecting piece obtained by cutting a part of a wall surface of said cup-shaped electrode inward. 3. An electron gun assembly for a cathode ray tube according to claim 1, wherein said projecting portion is a projection which extrudes a part of a wall surface of said cup-shaped electrode inward.