KR100492789B1 - Electron gun for CPT - Google Patents

Abstract

The present invention relates to an electron gun for a color cathode ray tube, having an electron gun for generating three electron beams and directing the electron beams along a non-pass hole on the same plane toward a fluorescent surface, and having a main lens for focusing three electron beams. The main focusing lens is formed by two spacer electrodes each having three inline openings, and each of the electrodes forms a main focusing lens in a color cathode ray tube having a portion consisting of rim electrodes facing each other. Each electrode having three in-line openings is composed of a plate electrode, and each electrode is composed of a rim electrode facing each other, so that the fifth grid electrode and the sixth grid electrode have the same shape and the same dimension. It's about an electron gun.

Description

Electron gun for color cathode ray tube {Electron gun for CPT}

The present invention relates to a color receiver having an inline electron gun having an improved main lens unit, and more particularly, to correct astigmatism formed by an enlarged focusing lens and to advantageously adjust static convergence (STC). Extended focused lens type electron gun electrode

As the color receiver becomes larger, a high anode voltage is required in order to obtain a focused spot on the screen while the electron beam from the cathode maintains a constant speed. This high anode voltage generates a high voltage difference from the focus voltage, and the main lens electrode close to the cathode deeply penetrates in the electrostatic lens of the main lens to generate spherical aberration. In addition, as the electron beam passes through the deflection yoke and has a flare around the nucleus, warpage occurs, and the horizontal direction of the electron beam becomes under focusing and over focusing in the vertical plane.

In order to improve the astigmatism, the opposing surface constituting the main lens portion is composed of a rim electrode, and an electrode plate formed with openings is retracted from the rim electrode, and the opening portion is formed in an elliptical shape with a long vertical axis. It was a common practice.

The effect of this main focusing lens can provide a gentle voltage gradient to reduce spherical aberration, and the vertical horizontal electron beam (Beam) can improve astigmatism. If it is difficult and elliptical, overconcentration occurs at the end of the vertical part of the oval opening of the focus electrode side, and if an asymmetric elliptical opening is installed, the horizontal beam is located in the green beam direction and the outer sidewall direction. The difference in focusing force is generated, which causes the spot to be distorted.

The present invention has been made to solve the above-mentioned problems of the prior art, issuing a beam consisting of one center beam and two outer beams and in-line electron gun that focuses toward the screen screen through the openings on one plane The in-line electron gun includes a bi-potential lens and a uni-potential lens to focus the electron beams, and has a main focusing lens so that each main focusing lens has three inline holes. To provide an electron gun for a color cathode ray tube formed by two spaced apart electrodes having a.

A characteristic feature of an electron gun for a color cathode ray tube according to the present invention includes a main lens for generating three electron beams and focusing the three electron beams with an electron gun for directing the electron beams along a non-pass hole on the same plane toward a fluorescent plane. The main focusing lens is formed by two spacer electrodes each having three in-line openings, and each electrode forms a main focusing lens in a color cathode ray tube having a portion consisting of rim electrodes facing each other. When the electrode having two in-line openings are composed of plate electrodes and each electrode is composed of rim electrodes facing each other, the fifth grid electrode and the sixth grid electrode have the same shape and the same dimension for the color cathode ray tube To provide an electron gun.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the electron gun for color cathode ray tube of the present invention will be described in more detail.

Fig. 1 is a cross-sectional view of main parts of an inline electron gun for explaining one preferred embodiment of a color cathode ray tube according to the present invention, wherein cathodes emitting three electron beams are respectively (11a), (11b) and (11c). In front of the control electrodes G1 (10), screen electrodes G2 (20), G4 (40), acceleration electrodes G3 (30), (32), and main focusing electrodes G5 (50) (52) close to the cathode; 54, 56, and main focusing electrodes 54, 56, 58 in close proximity to the screen.

In order to facilitate the static convergence of the other two beams with respect to the center beam in the electron gun, S and the third electrode forming a distance between the center of the opening of the first electrode 10 and the second electrode 20 and the center of the outer opening of the first electrode 10 and the second electrode 20. S1 which 30 has is formed differently.

That is, by making S1 larger than S to have a refractive lens to achieve the first static convergence, while the electron beam passing the cross over point passes through the third electrode 30, the focusing force is weakened in the horizontal direction. The vertical beams form long slots 30a ', 30b' and 30c 'in the vertical direction so as to act as quadrupoles to strengthen the focusing force.

The slot is 8.8mm high and 1.6mm wide and 0.4mm deep and applies the same dimensions to 30a '30b' 30c '.

For the second static convergence, the pitch of the beam through hole (S2), which is the upper electrode of the third electrode, is formed smaller than S1 so that the outer beam can be refracted to the center beam axis.

The third static convergence forms an asymmetric electrostatic lens by forming the openings 50a, 50b, 50c of the fifth electrode 50 larger than the openings 40a, 40b, 40c of the fourth electrode 42. The side beam is concentrated to the center beam side.

The third static convergence makes it possible to employ the same electrodes having the common dimensions of the electrodes 54, 56 and 58, 60 forming the main focusing lens portion.

FIG. 2 is a partial perspective view illustrating the main focusing lens unit of AA ′ of FIG. 1.

As shown in the figure, the fifth electrode 56 and the sixth electrode 56 form an opposing surface, and an opening for passing an electron beam corresponding to three colors of R, G, and B is formed after the opposing surface electrode. And install the plate electrode.

In this case, the rim electrode 56 has the fifth electrode 56 and the sixth electrode 58 facing each other in order to increase the effective diameter of the main lens as much as possible, and the size and the size of the rim electrode are 86.5% of the l and h of the outer surface of the electrode. As far as possible.

As such, by employing the extended rim electrode, there is an advantage that the size ratio of the horizontal axis and the vertical axis of the opening of the plate electrode connected to the rim electrode can be at least reduced.

That is, when h 'is reduced, in the electron gun adopting one electrostatic focusing method, in order to obtain a beam spot that is vertically larger than the horizontal, the main focusing lens is formed with the vertical axis as much as possible in order to form the openings of the electrodes. The sixth electrode should be made smaller than the size of the vertical axis, but if the size of the sixth electrode is small, the spot size is sensitive to the focus voltage because the focusing force is shown on the vertical axis of the kettle lens.

3 is a plan view of the plate electrode 54. In the aperture shapes 54a, 54b, 54c of the plate electrode, the aperture through which the center beam passes is used to determine the ratio of the core to the total edge beam of the horizontal axis of the beam spot reaching the screen. In order to increase the vertical hole in the rectangular hole at the end of the vertical axis of the opening at the distance H point at the center H by installing a circle to adjust the focusing strength of the vertical axis to adjust the spot.

The shapes 54a and 54c of the side beam through-holes have a shape similar to a key hole to form a circle having a different opening radius from a surface close to the center beam through-hole and a surface close to the wall of the outer circumferential electrode.

The through-holes of both side beams are in the horizontal direction (H), and the parts in contact with the center-beam through-hole and the outer wall are composed of r1 and r2, respectively, and form a perforated line extending in the vertical axis direction at the end of the circle. We also meet a large circle of r3 where this straight part ends.

The circle of r3 has the origin 100 at the center beam through hole side than the side beam through hole center side. In other words, each of the three circles consists of the following relationship: r1 <r2 <r3 The center axis origin is r1 = r2> r3 There is a relationship.

By constructing each circle in the horizontal direction of the through hole, it has the advantage that it can be supported by a beading jig rod when assembling the electron gun.

In addition, since the fifth grid electrode and the sixth grid electrode 54 and 56 of the main focusing electrode are commonly used, the horizontal electrostatic lens is increased by increasing r1 and r2 and decreasing l to adjust the horizontal focusing of the beam. It can weaken and prevent over-focusing, increasing the nucleus component, and by making three static convergence before the electron beam reaches the main focusing lens, the horizontal beam of the electron beam arriving at the main focusing lens is moved inward from the beam center. The focusing force is stronger than the beam in the outward direction, so that the spot where the beam arrives on the screen contains many hello components in the inward direction.

In order to remove the hello component, by increasing the l1 larger than the opening l2 of the electrode and h1 larger than h2, the hello component can be reduced by obtaining the main lens increased inwardly.

However, when r1 is increased, the focusing force in the horizontal direction is so weak that it causes astigmatism, and the side beam deflection is greater, which may weaken the static convergence characteristic.

In the static focus method, in order to compensate the beam spread in the periphery of the screen due to deflection aberration, the beam center is required to have a beam spot larger than the horizontal in the center of the screen. To satisfy this requirement, by increasing the l, h1, and h2, The sensitivity of astigmatism can be minimized by adjusting ℓ1 and ℓ2 by moving the origin of r3 to reduce the difference of excessive focusing force in the horizontal and vertical directions.

4 shows the amount of static convergence with increasing l1 and r1.

In other words, it can be seen that the static convergence increases with the increase of r1 rather than the increase of ℓ.

Therefore, in order to compensate for over-focusing while compensating for the lateral hello component, it can be easily corrected by adjusting r1 and l1.

Also, the change in beam spot is shown when r1, r2 and r3 are set to constant values and l is increased or decreased.

5 shows that the beam in the horizontal direction of the spot shows a slight change by increasing the value of l, but the vertical axis direction of the spot is greatly enlarged. In other words, increasing the value of l can reduce astigmatism.

6 shows the improved spot size of the side beams on the screen according to the specific embodiment shown in Table 1, which shows that the side beam through holes 54a and 54c are electron beams in the plate electrode 54 of FIG. It is easy to adjust the effect of the beam by the electron lens intensity on the whole direction of.

As described above, by providing the electron gun for the color cathode ray tube according to the present invention, it provides an effect that can reduce the hello in the inner direction of the side beam. Furthermore, it provides an effect of improving the focus characteristic and the static convergence characteristic by minimizing astigmatism.

In addition, it provides the advantage that the size and convergence of the inside and outside of the spot of the electron beam can be adjusted.

1 is a cross-sectional view including three electron gun shafts showing the configuration of an inline electron gun according to one embodiment of the present invention;

2 is a partial cross-sectional view showing the main lens unit of the present invention;

3 is a plan view showing the plate electrode of FIG.

4A and 4B are graphs showing the static convergence characteristics according to the size of the openings of the fifth and sixth electrodes.

FIG. 5 is a graph illustrating spot changes according to values of l in the side beam through holes of the fifth and sixth electrodes.

Fig. 6 is a craft comparing the relationship between the focus voltage and the spot according to the present invention with the conventional electron gun.

Explanation of symbols on the main parts of the drawings

1, 30a, 30b, 30c ... slotted, 2, 54 ... plate electrode,

3, 56 ..... limb electrodes, 4, 54a, 54c ... asymmetric keyhole with 3 r.

Claims (3)

In the electron gun for a color cathode ray tube comprising a main lens for converging three electron beams, the main focusing lens is composed of a plate electrode having three inline openings, each electrode comprising a rim electrode facing each other , The fifth grid electrode and the sixth grid electrode are configured to have the same shape and the same dimension, The plate electrode is formed with three beam through holes, In the above three beam through holes, the side beam through holes are formed in a circle having an inner r1 and an outer r2 at the center of the through holes, and have an origin r3 inward from the center of the side beam through holes, An electron gun for a color cathode ray tube, wherein an opening is formed in a straight line at r3 at an end line. The electron gun for color cathode ray tubes according to claim 1, wherein when the origin of r3 is larger than the origin of r1 and r2, the aperture has a larger opening than h1 from h2. The method of claim 1, wherein r1 and r2 of the side beam through hole of the electrode plate is smaller than r3 and l1 and l2 of the opening formed by a straight line extending from r1 and r2 have different dimensions, respectively, the center of the through hole H1 met on r3 And h2 A color cathode ray tube electron gun, wherein h1 is equal to or greater than h2.

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