KR100499939B1 - Electron gun for Color CRT - Google Patents

Abstract

The present invention relates to a color cathode ray tube, and more particularly, a plate electrode having the same electron beam through hole as the electron beam through hole of the final anode electrode is welded between the shield cup electrode and the final anode electrode. The purpose is to prevent deformation of the anode electrode.

The present invention provides a cathode, which emits an electron beam toward a phosphor screen, a control electrode, an acceleration electrode, a focusing electrode and an anode electrode, and a deflection yoke of the plurality of electrodes sequentially having a predetermined distance from the cathode. In an electron gun for a cathode ray tube including a shield cup, which is a shielding electrode for shielding a leakage magnetic field, the focusing electrode includes a cup electrode and a cap electrode, and the anode electrode includes a cup electrode. To; A plate-shaped first guide inner electrode may be formed between the shield cup and the anode electrode.

Description

Electron gun for color cathode ray tube {Electron gun for Color CRT}

The present invention relates to a color cathode ray tube, and more particularly, to an electron gun for a color cathode ray tube in which a plate-shaped inner electrode is formed between a shield cup and a final anode electrode.

Looking at the configuration of a general color water pipe, as shown in Figure 1, the color water pipe is composed of a brown tube 100 and the deflection yoke (2), the brown tube 100 is a red, green, blue phosphor on the front inner surface And a panel 6 having a fluorescent surface 8 coated with a shadow mask 3 having a color screening function, and a funnel 5 having a tubular neck portion 4 formed at a rear side thereof. It consists of.

In addition, an electron gun 1 is embedded inside the neck portion 4 of the funnel 5, and a deflection yoke 2 for deflecting the electron beam 7 emitted from the electron gun in a horizontal direction or a vertical direction is coupled thereto. .

As shown in FIG. 2, each of the electrodes constituting the electron gun is fixed with a bead glass 9 at regular intervals in order to focus the electron beam on the screen. After that, a virtual electron lens is formed by applying a constant voltage to each electrode.

In general, the electron gun 1 includes a first electrode 11, which is a common lattice of three cathodes 10 that are independent of each other, and three cathodes 10 that are disposed at a predetermined distance from the cathode, and the first electrode 11. ), The second electrode 12, the third electrode 14, and the fourth electrode 15 disposed in a predetermined interval, and the electron gun 1 and the tube are electrically connected to the fourth electrode 14. It is configured in order of the shield cup 16 is attached to the BSC (bulb space connector) 17 serves to fix the electron gun 1 to the neck portion of the tube while connecting.

In addition, referring to the operation of the electron gun, the heater 18 embedded in the cathode 10 is connected to a power source through the stem pin 19 to emit electrons from the cathode surface, and the electrons are the first electrode which is the control electrode. The electron beam 7 is controlled by (11), the electron beam 7 is accelerated by the second electrode 12, which is an acceleration electrode, and the third electrode 14, which is a focusing electrode, and the fourth electrode 15, which is an anode electrode. ) Constitutes the main lens unit to focus and finally accelerate the electron beam 7 generated in the triode, and passes through the shadow mask 3 provided on the inner surface of the screen to collide with the fluorescent surface 8 to emit light.

Here, the control electrode 11 is grounded, the acceleration electrode 12 is applied with a high voltage of 500-1000v, the anode 15 is 25-35KV, and the focusing electrode 14 has a voltage of 20 at the anode 15. An intermediate voltage of ˜30% is applied.

The focusing electrode 11 includes a cup electrode 14-1, a guide cup electrode 14-2, and a cap electrode 14-3, and a guide cup electrode 14-2. Is formed between the Cap electrode 14-3 and the Cup electrode 14-1. The final anode electrode 15 is composed of a cup electrode 15-1 and a guide cup electrode 15-2, which is a shield cup 16 and a cup electrode 15. It is comprised between -1).

The focusing electrode 14 and the anode electrode 15 are main lens forming electrodes, and the shield cup 16 is formed farthest from the cathode 10, and shields and weakens the shielding magnetic field of the deflection yoke. It serves as a shielding electrode.

In the conventional electron gun, the cap electrode 14-1 of the focusing electrode 14 and the cup electrode 15-1 of the final anode electrode 15 face each other. It is formed and thereby serves to focus the electron beam 7 on the screen. This electrostatic lens is called a main lens, and the main lens has spherical aberration.

In general, the pixel size of the electron beam is due to the influence of spherical aberration.

Due to this effect, when the spherical aberration is large, the electron beam acts to reduce the sharpness, thereby degrading the resolution, and the periphery of the deflection region also acts in the same manner.

Such spherical aberration is inversely proportional to the third power of the main focusing electrostatic lens aperture R, as can be seen by the formula described below, and the aperture R of the electrostatic focusing lens is almost proportional to the diameter of the focusing electrode and the final accelerating electrode. do.

That is, the lens between the focusing and the final acceleration electrode is called the main lens, and as the diameter of the main lens increases, the focusing intensity decreases, and the pixels form an image in front of the screen and the focusing voltage decreases.

Therefore, when the concentration of the electron gun 1 is taken to maintain the same focusing voltage and the focusing intensity is taken, the larger the diameter of the main lens is, the smaller the size of the pixel can be and the sharpness can be improved.

Thus, the size Ds of the final pixel on the screen is as follows.

Ds =

(Dx: magnification of main lens, Dsa: spherical aberration, Dsc: electron beam expanding component by space charge repulsion effect)

Therefore, when the space charge repulsion effect is increased, the pixels become larger due to the repulsive force, and when the electron beam radius is increased to suppress the repulsion effect, spherical aberration increases, so that the optimum conditions should be found.

In addition, the spherical aberration has a different sensitivity depending on the burring length of the cap electrode 14-3 of the focusing electrode and the cup electrode 15-1 of the positive electrode. (Burring) There is a technique in which the length is 70% or more of the pore size.

However, as shown in FIG. 3, the conventional technique has a burring length because the distance of the three electron beam through holes is 4.75 mm and the pore size is 3.90 mm, and the bridge width is only 0.85 mm. It is not possible to grow more than 70%, and as shown in FIG. 4, the burring length is 70% by inserting the guide cup 14-2 of the focusing electrode and the guide cup 15-2 of the positive electrode. It was configured to be.

Therefore, the guide cup not only serves as a guide but also plays an important role in determining the spherical aberration of the main lens.

However, the main lens of the electron gun is a combination of four components, that is, a cap 14-3 of the focusing electrode 14, a guide cup 14-2, and a cup Cup of the anode electrode 15. Composed of a combination of electrodes 15-1 and guide cups 15-2, various problems arise when assembling four parts.

That is, as shown in FIG. 4, a burring length L1 is formed by the cup electrode 15-1 and the guide cup electrode 15-2 of the anode, and the burring length. L1 depends on the distribution of the height dimension 11 of the cup 15-1 and the height dimension 12 of the guide cup, thereby causing a problem that the focusing force of the three electron beams is different. .

In addition, as shown in FIG. 5A, the cup 15-1 of the anode electrode during beading welding, which is a process of fusing each electrode by a pair of bead glass 9, is performed. And a change in the dimension V1 in the vertical direction of the guide cup electrode 15-2 from V1 in FIG. 4 to V11 in FIG. 5A occurs. As shown in FIG. 5B, the cap electrode 15-1 ) And the diameter of the guide cup electrode 15-2 has a tilt shape, which causes a problem of changing the path of the electron beam.

This problem changes the arrangement of the three electron beams on the screen, reducing the concentration of the three electron beams, resulting in poor resolution.

Accordingly, an object of the present invention is to solve the conventional problems, and to form a guide inner electrode of the plate between the focusing electrode, the anode electrode and the shield cup, the deformation of the final anode electrode during the beading operation to fuse the bead glass The purpose of the present invention is to provide an electron gun which can prevent the scattering of the quality by acting as a guide of the pure electron beam.

The present invention for achieving the object as described above, the cathode, which emits an electron beam toward the phosphor screen, the control electrode, the acceleration electrode, the focusing electrode and the positive electrode, and at a predetermined interval from the cathode sequentially, the plurality of In an electron gun for a cathode ray tube including a shield cup which is a shielding electrode for shielding the leakage magnetic field of the deflection yoke of the electrodes, the focusing electrode includes a cup electrode and a cap electrode, the anode electrode is a cup ( Cup) electrode; A plate-shaped first guide inner electrode may be formed between the shield cup and the anode electrode.

Still another technical solution includes a cathode for emitting an electron beam toward a phosphor screen, a control electrode, an acceleration electrode, a focusing electrode and an anode electrode, and a deflection yoke of the plurality of electrodes sequentially having a predetermined distance from the cathode. In an electron gun for a cathode ray tube including a shield cup, which is a shielding electrode for shielding a leakage magnetic field, the focusing electrode includes a cup electrode and a cap electrode, and the anode electrode includes a cup electrode. To; The plate-shaped second guide inner electrode may be formed between the cup electrode and the cap electrode of the focusing electrode.

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

In the conventional electron gun, the guide cup electrode is difficult to lengthen the burring length of the cap electrode and the cup electrode to 70%, so it is applied at a level of 50% and generates spherical aberration. It was formed in order to minimize the deformation of the focusing electrode and the anode electrode, it was practically unnecessary electrode.

Therefore, as shown in FIG. 6, a plate-shaped first guide inner electrode 15-3 is formed between the shield cup 16 and the anode electrode 15.

That is, when the first guide inner electrode 15-3 is not inserted into the anode electrode 15, the amount of change from V2 to V22 compared to the prior art during the beading as shown in FIGS. 7A and 7B. This appears more largely, which causes damage to the plane of the cup electrode 15-1 forming the main lens.

Accordingly, as shown in FIG. 8, the conventional electron gun pixel shows a pixel of fine length, but astigmatism is changed according to the change of the plan view, and thus the vertical direction has halo and the blooming has a blooming shape. Greatly deteriorated.

That is, the astigmatism refers to the H-just voltage-V-just voltage difference and should generally have about 300 to 500V. However, an abnormal shape occurred in the range of -500 to -800V through the change of the top view.

And the thickness was applied to 0.5 ~ 0.7mm to change the small, the hole size of the guide inner electrode (15-3) is the same as the hole size of the main lens, it was configured to facilitate the work during the beading (Beading).

Therefore, the conventional guide cup electrodes 14-2 and 15-2 are used for correcting the main lens spherical aberration instead of the guide role, and thus exhibit sensitive quality distribution according to the dimensional distribution and the operation. 1) can reduce the dispersion of quality because the guide inner electrode of the plate acts as a pure guide.

9, the guide cup electrode 14-2 in the focusing electrode 14 is removed, and the second guide inner electrode 14-4 is inserted.

In addition, the conventional guide cup electrode 14-2 has a cup shape, which is disadvantageous in deformation, and thus the plate-shaped second guide inner electrode 14-4 is thick so that there is no change during beading. It was.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

Therefore, according to the present invention, the plate-shaped electrode having the same electron beam passing hole as the electron beam passing hole of the final anode electrode is welded between the shield cup electrode and the final anode electrode, thereby preventing deformation of the final anode electrode during the beading operation. have.

1 is a cross-sectional view of a general color cathode ray tube.

2 is a cross-sectional view of an electron gun of a conventional color cathode ray tube.

3 is a cross-sectional view showing an electrode of an electron gun.

4 is a view showing the positive electrode and the guide cup before the beading (Beading) according to the prior art.

Figure 5a is a view showing a modified anode and guide cup during the beading (Beading) according to the prior art.

5B is a sectional view of the electrode of the modified electron gun;

6 is a view showing a plate-shaped first guide inner electrode between the anode electrode and the shield cup according to the present invention.

FIG. 7 is a view illustrating an electrode deformed when beading without inserting a plate-shaped guide inner electrode. FIG.

8 is a graph showing spot size changes according to astigmatism.

9 is a view showing a plate-shaped second guide mermaid electrode between a cap electrode and a cup electrode of the focusing electrode according to the present invention.

10 is a view showing an electron gun in which a guide inner electrode is formed on the anode and the focusing electrode according to the present invention;

*** Explanation of symbols for the main parts of the drawing ***

1: electron gun 7: electron beam

14: focused electrode 14-1: cup electrode of the focused electrode

14-2: Guide cup electrode of focusing electrode 14-3: Cap electrode of focusing electrode

14-4: Second guide inner electrode 15-1: Cup electrode of positive electrode

15-2: Guide cup electrode of positive electrode 15-3: First guide inner electrode

Claims (6)

A cathode that emits an electron beam toward the phosphor screen, and a shielding electrode that shields a leakage magnetic field of the deflection yoke of the plurality of electrodes sequentially with a control electrode, an acceleration electrode, a focusing electrode and an anode electrode, and a predetermined distance from the cathode; In the electron gun for a cathode ray tube comprising a shield cup, wherein the focusing electrode includes a cup electrode and a cap electrode, the anode electrode includes a cup electrode, A plate-shaped first guide inner electrode having a pore size equal to the pore size of the cup electrode is formed between the shield cup and the anode electrode, An electron gun for a cathode ray tube, wherein a plate-shaped second guide inner electrode is formed between the cup electrode and the cap electrode of the focusing electrode. The method of claim 1, The plate-shaped first and second guide inner electrodes are formed in a thickness of 0.5mm ~ 0.6mm electron gun for cathode ray tube. The method of claim 1, The thickness of the first and second guide inner electrode on the plate is 1.8 times thicker than the thickness of the cap electrode and the cup electrode, characterized in that the electron gun for the cathode ray tube. delete delete delete