JP2570700B2 - Electron gun electrode assembly - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode assembly for improving the resolution of an electron lens of an in-line type color cathode ray tube electron gun.

[Conventional technology]

The resolution of an electron gun for a cathode ray tube is mainly limited by the spherical aberration of the electron lens. To obtain high resolution characteristics, it is necessary to increase the diameter of the electrode constituting the main electron lens and reduce the spherical aberration of the electron lens. In an in-line type electron gun in which three apertures through which an electron beam passes are arranged in a straight line, simply increasing the aperture of the main electron lens increases the eccentric distance, which is the distance between the apertures, and seals the electron gun. It is necessary to increase the neck diameter of the cathode ray tube to be stopped.

In general, an increase in the eccentric distance degrades the convergence characteristic of concentrating three electron beams at one point over the entire phosphor screen, and an increase in the neck diameter leads to an increase in the deflection power when a cathode ray tube is used. is not.

Therefore, as shown in FIGS. 4 to 6, as a method of increasing the aperture of the main electron lens constituting electrode without changing the eccentric distance S and the neck diameter of the in-line type electron gun, the applicant has disclosed in Japanese Patent Application Laid-Open No. has a diameter D ₀ of more than three apertures eccentricity distance S as shown in No. -9036, it includes a recessed portion of the communicating hole shape that is inline by superimposing the three apertures from each other, projecting with an edge at the bottom An electrode structure with independent openings is proposed.

FIG. 4 is a cutaway perspective view of a main part of the closed cylindrical body electrode 1 which is a focusing electrode based on this proposal, FIG. 5 is a top view, FIG. 6 is a side sectional view, and FIG. The focusing electrode is
Side sectional views of an electron gun structure in which a G3 electrode 18 and a G4 electrode 19 as an anode electrode are opposed to each other to form a bi-potential focus type main electron lens are shown. The closed cylindrical body electrode 1 has a diameter D ₀ that is equal to or greater than the opening eccentric distance S on the first closed surface 12.
An opening end of a cylindrical side portion 13 perpendicular to the first closing surface 12 is formed with a communication hole recessed portion 11 in which three openings 11R, 11G, 11B having On the side, a flange-shaped edge 15 having an electrode support 14 parallel to the closing surface is integrally formed.
Recess 11 is formed in the internal electrode at a distance h ₀ of 0.2 to 0.6 times the opening diameter D ₀ from the first blocking surface 12, the bottom surface forms a second closing surface parallel to the first closing surface 12 Has three apertures
11R, 11G11B is mutually communicated, three apertures surrounding the superimposed continuous sidewall height h ₀ with constricted portion 17 to the opening superimposing unit
Surrounded by 11W.

Furthermore, three holes are formed in the second closed surface 11 of the communication hole-shaped concave portion.
11R, 11G, 11B coaxial its opening diameter with D ₀ smaller diameter D _1, the opening to form a complete circular hole which respectively are independent 16R, 16
G, 16B is bored, protruding edges 1 of the rim height h ₁ of the severally
Surrounded by 6W.

The electrode having this structure is a focusing electrode as shown in FIG.
G ₃ electrode 18 and the central and formed to face a G ₄ electrode 19 is an anode electrode, an electron lens of a double outer apertures in the interaction of independent complete circular hole portion continuous thereto and the superposition type large diameter portion The spherical aberration is extremely small, and the lens action in the horizontal direction, which is the direction in which the apertures of the central and outer electron lenses are arranged, and in the direction perpendicular thereto is uniform, and the resolution characteristics of the electronic lens are significantly improved.

[Problems to be solved by the invention]

However, in the electrode structure of the above structure, the three holes are superimposed on each other, and an independent perfect circular hole with a protruding edge is integrally formed on the bottom surface of the communicating hole-shaped concave portion which is arranged inline. However, there is a disadvantage that the electrode formation processing becomes difficult and the electrode forming process becomes difficult. In this case, the formation of the communication hole shaped recess, and the formation of the projecting edge with separate circular hole having a predetermined height h ₁ in the recess in the bottom surface is particularly difficult.

Furthermore, by increasing the superposition type opening diameter D ₀ of the first closing surface 12,
As the degree of superposition of the apertures is increased, the spherical aberration of the central and both outer electron lenses is further reduced, but the width of the constricted portion 17 between the central aperture 11G and both outer apertures 11R and 11B increases, The astigmatism in which the focusing action in the horizontal direction is weaker than that in the vertical direction becomes remarkable in the electron lens in the central aperture. Therefore, the optimal focusing voltage in the horizontal direction is lower than that in the vertical direction, the electron beam spot on the phosphor screen formed by the central electron lens becomes extremely long, and its resolution is deteriorated compared to the outer electron lenses. there were.

The present invention has been made in view of the above-described drawbacks, and has an electrode in which three closed holes are overlapped with each other on a closed surface to form a communication hole formed in-line and a protruding edge is formed inside the electrode. The main electron lens is constituted by an electrode assembly having an independent opening and an electrode disposed at a predetermined distance from the closed surface to face the main electron lens, and is limited to difficulties in electrode formation processing and dimensional restrictions. An object of the present invention is to provide an electron gun electrode assembly having electrodes having a uniform structure, uniform resolution characteristics of the center and both outer electron lenses, an extremely excellent resolution, a simple structure, and electrodes which can be easily formed.

[Means for solving the problem]

The present invention has a hole diameter of not less than the eccentric distance between the three holes arranged in-line on the closed surface of the closed cylindrical electrode, a communication hole formed only by an arc by overlapping the three holes mutually. The hole is bored without protruding from the closed surface, and an independent opening with a protruding edge is provided inside the electrode, a predetermined distance from the closed surface, and the tip of the protruding edge is on the opposite side to the closed surface. A main electron lens electrode is constituted by a nested auxiliary electrode installed so as to protrude into the main electron lens, and the main electron lens is formed by separating the pair of electrode assemblies so that the communication hole perforated surfaces face each other. In addition, the diameter of the communication hole of the electrode structure at a relatively high potential is set relatively smaller than that of the electrode structure on the low potential side, and the center opening diameter of at least one of the communication holes of the electrode structure is smaller than that on both outer sides. is there.

By configuring the electrodes in this manner, the aperture structure of the main electron lens can be greatly simplified, the electrode can be easily formed, and the overlapped aperture diameter is larger than that of a conventional electrode having a concave portion. It is possible to set it even larger,
By making the electron lens action of the center and the outer opening portions the same in the horizontal and vertical directions in which the apertures are arranged, a large-diameter electron lens with extremely excellent resolution characteristics can be obtained.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an electrode structure according to an embodiment of the present invention as a G3 electrode 2 and a G4 electrode 4 which are opposed to each other.
2 (a) and 2 (c) are a perspective view, a top view, and a sectional view, respectively, showing a closed cylindrical body electrode 20 constituting the G3 electrode 2. FIG. 3 (b) is a perspective view of an auxiliary electrode 3 nested on the electrode 20, and FIG. 3 is a closed cylindrical electrode constituting a G4 electrode 4.
40 shows a top view.

As shown in FIG. 2 (a), the closed tubular body electrode 20 extends substantially perpendicularly to the closed side 22 having a substantially elliptical shape, a cylindrical side portion 23 perpendicular thereto, and the cylindrical side portion 23 continuously therefrom. flange-like rim 25 having an electrode Shijiko 24 which are are line arrangement with an aperture eccentricity distance S above opening diameter D _a is the opening between the center distance is the closing surface 22 formed integrally Center and both outer holes 21G, 21R, 21
A communication hole 21 is formed in which a part of a circle is missing by superimposing B, and a communication hole 21 having a partially circular superimposed shape constituted only by an arc is formed.

As shown in FIG. 1, the auxiliary electrodes 3 shown in FIG. 2 (b) are closed cylindrical electrodes 20, 4 constituting the G3 electrode 2 and the G4 electrode 4.
It is also a closed cylindrical body that fits telescopically inside 0,
A closed surface 32, a cylindrical side portion 33 perpendicular to the closed surface 32, and a flanged edge 35 having an electrode support 34 corresponding to the aforementioned flanged edge 25 projecting vertically to the cylindrical side portion are integrally formed. . Inline arranged with a diameter D ₁ to form a completely circular hole in the following opening eccentricity distance S is in the closed surface 32 a three apertures 31R, 31G, 31B is bored, its respective protrudes inside, high It is surrounded by a protruding edge 31W of h _1. As shown in FIG. 1, the cylinder side length of the closed cylindrical body electrode 20 and the auxiliary electrode 3 is determined when the auxiliary electrode 3 is fitted into the closed cylindrical body electrode 20 and the flanges 25 and 35 are overlapped. , the distance between both closing surface is set to a predetermined height h _0.

On the other hand, as shown in FIG. 3, the closed cylindrical body electrode 40 constituting the G4 electrode 4 is a closed cylindrical body having substantially the same shape as the closed cylindrical body electrode 20, and includes an oval closed surface 42 and an oval closed surface 42. Tube side perpendicular to
43, a flange-like edge 45 having an electrode support 44 extending perpendicularly thereto is integrally formed. The closing surface 42 is slightly larger than the opening eccentricity distance S above the G3 electrode 2 S 'or more central opening diameter D _C, is line arrangement with both outer opening diameter D _S central and two outer apertures 41G, A communication hole 41 is formed by superimposing 41R and 41B to form a partially circular superimposed type formed only by an arc.

However, the relationship between the opening diameters of the G3 electrode 2 and the G4 electrode 4 and the eccentric distance is D _A > D _S > D _C > S ′ ≧ S, and the opening diameters D _S and D _C of the G 4 electrode 4 are either smaller than the opening diameter D _a relatively G3 electrode also and central aperture 41G is two outer apertures of the communicating hole 41
It is set smaller than R and 41B.

As shown in FIG. 1, the auxiliary electrode 3 is fitted to the closed cylindrical body electrode 20 to form a G3 electrode, and the closed cylindrical body electrode 40 is similarly connected to the auxiliary electrode 3 '(S' with respect to the eccentric distance S of the auxiliary electrode 3). The G4 electrodes 4 are fitted together to form a bi-potential focus type microwave oven with the communication holes facing each other at a predetermined distance to form the communication holes 21 and 4 having a superposed large diameter.
1 and independent opening portions 31R, 31R '; 31 with protruding edges at the back
G, 31G '; 31B, 31B' form an electron lens. As a combined effect of the superposition type large-aperture electron lens and the independent small-aperture electron lens, an independent large-aperture electron lens having extremely small spherical aberration is formed at the opposing portion of the G3 electrode 2 and the G4 electrode 4.

On the other hand, the independent openings 31R, 31G, 31 on the G3 electrode 2 side shown in FIG.
Closed surface 32 with B formed and closed surface 2 with communication hole 21 formed
The distance h ₀ between 2 and simulation using the computer simulation, the superposition type opening diameter D _A, began with the best focusing properties are obtained if you choose to 0.2 to 0.6 times the D _S.

 This relationship is similarly established on the G4 electrode 4 side.

In general, in a bi-potential focus type electron lens, a focusing lens is formed on the G3 electrode 2 side to which a focusing voltage is applied, and a diverging lens is formed on the G4 electrode 4 side to which an anode voltage is applied. Also, in the superimposed apertured electron lens, the aperture diameter in the in-line aperture arrangement direction and the aperture diameter in the vertical direction are smaller than the aperture diameter in the horizontal direction, so that the focusing action in the vertical direction is stronger than in the horizontal direction, and the electron beam spot on the fluorescent surface is Distorted horizontally. Especially since the central opening has no partitions on both outer parts,
In the central electron lens, the focusing effect in the vertical direction is significantly stronger than the focusing effect in the horizontal direction as compared with the outer electron lenses, and astigmatism in which the optimum focusing voltage greatly differs between the vertical direction and the horizontal direction becomes remarkable.

However, in the present application, the opening diameter of the overlap type opening 41 of the G4 electrode 4 is
Since it is set to be smaller than that of the G3 electrode 2, the diverging lens formed on the G4 electrode 4 side is stronger than when both have the same diameter. Conversely, the function of the focusing lens is weakened, and in particular, the focusing action in the vertical direction is weaker than when the diameter is the same as that of the G3 electrode 2, so that the optimum focusing voltages in the horizontal and vertical directions can be matched.

Further, the diameter D _C of the central opening 41G of the communication hole 41 on the G4 electrode 4 side.
Is set smaller than the diameter D _S of both outer openings 41R and 41B, so that the vertical focusing action of the central opening 41G can be weakened compared to the case where both the center and both outer openings have the same diameter. . Therefore, by choosing the diameter D _C appropriately, weakening the vertical focusing action of the central aperture 41G, horizontal, to be able to match the vertical optimum focusing voltage, the central and two outer apertures electron lens The focusing action is made uniform, the horizontal distortion of the electron beam spot is corrected to form a circular shape, and the astigmatism can be removed.

Also, since the width G of the constricted portion 47 can be made smaller than when the diameters of the three communication holes are equal, it is possible to enhance the central aperture side lens converging action of the both outer aperture electron lenses, and to increase the horizontal and vertical The lens function in the directions can be made uniform, and an electronic lens with extremely excellent resolution can be obtained.

With such an electrode configuration, the communication holes 21 and 41 having a large diameter larger than the opening eccentric distance S may be formed by simply forming communication holes in the closed surfaces 22 and 42. Since there is no need to form a side wall around the periphery, the formation of the hole becomes extremely easy, and the mass productivity of component processing is extremely high. Also, its communication hole
No side wall is required around 21,41, so it is not necessary to consider the dimensional restrictions associated with electrode formation.
If it is less than the short side width of 2,42, it can be set arbitrarily large. On the other hand, since the auxiliary electrode 3 is formed separately from the electrode main body having the communication hole, the relative distance h ₀ , the height h ₁ of the protruding edge, and the opening diameter D ₁ thereof are all limited to the shape of the communication hole. It can be set freely without being performed, and the electrode formation is also extremely easy.

In the above description, the opening eccentric distance S of the G3 electrode 2 is set to S 'which is slightly larger than S of the G4 electrode 4. As is well known, this is from the three cathodes to the inside of the G3 electrode 2. G3 is used to electrostatically concentrate the three electron beams that have traveled in parallel on the axes 20R, 20G, and 20B of the electron gun on the fluorescent screen at one point.
This is because the center of at least one of the communication hole 41 of the electrode 4 and the independent opening of the auxiliary electrode 3 'is decentered outward.

Further, in the above description, the case where the main electron lens is of a bi-potential focus type has been described. However, the present invention is not limited to this, and it is needless to say that the present invention can be applied to a multi-stage focusing type electron lens and the like. Absent.

〔The invention's effect〕

As described above, the communication hole portion having a large diameter larger than the opening eccentric distance only needs to form a superimposition-shaped oval communication hole on the closed surface of the closed cylindrical electrode, and the opening portion is formed. Is very easy, and the hole diameter can be set arbitrarily large as long as it is less than the short side width of the closed surface, and the horizontal and vertical focusing characteristics of the center and both outer electron lenses can be matched by a simple configuration, The resolution characteristics of the lens unit can be significantly improved. In addition, since the auxiliary electrode having a protruding edged opening facing the communication hole-shaped large-diameter electron lens portion is separate from the electrode body having the communication hole portion, it is only necessary to fit in a nested manner. , The relative position of the two, and the diameter and height of the protruding edge can be set arbitrarily without any dimensional restrictions constrained by the relationship with the formation of the communication hole, and constitutes an independent aperture Not only is it easy to form auxiliary electrodes, but also the optimal design of the electron lens system is facilitated.

[Brief description of the drawings]

FIG. 1 shows an electrode assembly according to one embodiment of the present invention as a G3 electrode,
FIGS. 2 (a) and 2 (b) are cross-sectional views of a main part of an electron gun electrode structure in which a bi-potential focus type electron lens is arranged facing each other as a G4 electrode. FIG. 3C is a perspective view of a body electrode, FIG. 3C is a perspective view of an auxiliary electrode nested in the electrode, FIG. 3 is a top view of a closed cylindrical body electrode constituting a G4 electrode, FIG. FIG. 4 is a cutaway perspective view of a main part of the closed tubular body electrode proposed prior to the present invention, FIGS. 5 and 6 are top views, side sectional views, and FIG. G3 electrode as a focusing electrode and G4 electrode as an anode electrode
The side sectional views of the electron gun electrode structure constituting the focus type electron lens are respectively shown. 1,20,30 …… Closed cylindrical electrode, 3,3 ′ …… Auxiliary electrode, 11…
... recessed part (second closed surface), 12 ... first closed surface, 22, 32, 42
…… Closed surface, 13,23,33,43 …… Cylinder side, 14,24,34,44 ……
Electrode support, 15,25,35,45 ......... Flanged edge, 11R, 11G, 11B; 21
R, 21G, 21B; 41R, 41G, 41B …… Circular overlapping superimposed holes, 21,41…
… Communication holes, 17, 27, 47 …… Constrictions, 16R, 16G, 16B; 31R, 31
G, 31B …… Full circular opening, 16W, 31W …… Projecting edge, 11W…
... recess sidewall, 20R, 20G, 20B ...... electron gun axis, D _C ...... segmental shaped superposition type opening of the central opening diameter, both outer opening diameter of D _S ...... segmental shape superimposed aperture.

Claims (1)

(57) [Claims] A communication hole having an opening diameter greater than the eccentric distance between three openings arranged in-line on the closing surface of the closing cylindrical electrode, and having three openings overlapping each other to form only a circular arc. A hole is formed without protruding from the closed surface, an independent opening with a protruding edge is provided inside the electrode, a predetermined distance is provided from the closed surface, and the protruding edge tip is opposite to the closed surface. A main electron lens electrode structure is constituted by a nested auxiliary electrode installed so as to protrude to the side, and the main electron lens is formed by separating a pair of the electrode structures so that the communication hole perforated surfaces face each other. The diameter of each of the communication holes of the electrode assembly on the relatively high potential side is set relatively smaller than the diameter of each of the communication holes on the low potential side, and the center of at least one of the communication holes of the electrode assembly is set. The opening diameter is smaller than the opening diameter on both sides. Child gun electrode structure.