KR100719532B1 - Electron gun for CPT - Google Patents

Abstract

 According to the present invention, a cathode, a control electrode, a screen electrode, a first to third focus electrode each having a first and second quadrupole lens forming therebetween, and the third focus electrode In the electron gun for a color cathode ray tube which is provided adjacent to the third focus electrode and the final acceleration electrode forming a main lens, the horizontal direction of the electron beam through holes formed in the electrode member of the focus electrode constituting the first quadrupole lens And a length in the vertical direction is smaller than the diameter of the circular electron beam passing hole formed in the electrode member of another adjacent electrode.

Description

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

1 is a side view showing an electron gun for a conventional color cathode ray tube;

2 and 3 are separated perspective views showing the shape of the electrode and the electron beam through-hole forming the quadrupole lens in the electron gun shown in FIG.

4 is a schematic perspective view of an electron gun for a color cathode ray tube according to the prior art;

5 is a side view showing an electron gun for a color cathode ray tube according to the present invention;

6 and 7 are schematic exploded perspective views of electrode members provided in FIG. 5.

8 is a schematic perspective view of a colored cathode ray tube according to the present invention;

9A and 9B are schematic front views showing the lateral uniformity of the prior art and the color cathode ray tube according to the present invention.

<Brief Description of Major Codes in Drawings>

21. cathode 22. control electrode

23. Screen electrode 24. First focus electrode

25. Second Focus Electrode 26. Third Focus Electrode

27. Fourth focus electrode 28. Fifth focus electrode

29. Final Acceleration Electrode

The present invention relates to an electron gun for a color cathode ray tube, and more particularly, to a dynamic focus electron gun for a color cathode ray tube in which an electron beam passing hole is formed so as to improve the horizontal line uniformity of a color cathode ray tube.

Typically, the electron gun for the color cathode ray tube is installed in the neck portion of the cathode ray tube to emit hot electrons, the performance of the cathode ray tube depends on the state in which the electron beam emitted from the electron gun is landing on the fluorescent film. Therefore, many electron guns have been developed to reduce the focus characteristic and the aberration of the electron lens so that the electron beam emitted from the electron gun can be accurately landed at the fluorescent point of the fluorescent film.

The dynamic focus electron gun having a single quadrupole lens has a disadvantage in that the vertical width of the horizontal line is severely changed as the electron beam is deflected to the periphery of the screen. In other words, as the electron beam is deflected toward the periphery of the screen, the vertical width of the horizontal line becomes smaller, so that a moire phenomenon or a bagging phenomenon occurs. The moiré phenomenon is a phenomenon in which light interference occurs when the window of the screen is installed at an angle on the screen of the cathode ray tube. This is caused by the interference between the shadow mask of the cathode ray tube and the electron beam, which causes waves or combs. will be. In particular, moiré phenomenon occurs when the size of the vertical cross section of the electron beam decreases. In addition, the bagging phenomenon is a kind of moiré phenomenon, in which a block or lattice-shaped interference fringe is displayed on the panel. This is a phenomenon in which vertical lines are distorted when the electron beam spot is severely thickened. In order to improve the moiré and the bagging phenomenon, a dual quadrupole lens system can be used.

Figure 1 shows an example of a conventional color cathode ray gun electron gun, which is a dynamic focus electron gun with a dual quadrupole lens.

Referring to the drawings, the electron guns are first, second, third and fourth of the cathode 2, the control electrode 3, and the screen electrode 4, which form the pre-triode, and are sequentially arranged adjacent thereto to form an auxiliary electrostatic lens. 5 focus electrodes 5, 6, 7, 8, 9, and a final acceleration electrode 10 disposed adjacent to the fifth focus electrode 9 to form a main electron lens.

2 and 3, an elongated electron beam for forming a first quadrupole lens is formed on the emission side of the third focus electrode 7 and the incident side of the fourth focus electrode 8, as shown in FIGS. 2 and 3. The through hole 7b and the transverse electron beam through hole 8a are formed on the same plane, respectively, on the exit side of the fourth focus electrode 8 and the incident side of the fifth focus electrode 9 of the focus electrodes. An elongated electron beam through hole 8b and another electron beam through hole 9a for forming the second quadrupole lens are formed on the same plane, respectively.

On the other hand, when looking at the voltage applied to each of the electrodes, a first constant voltage (V1) is applied to the control electrode 3, the screen electrode 4 and the second focus electrode 6 is higher than the first constant voltage The second constant voltage V2 is applied. A focus voltage VF higher than the second constant voltage is applied to the first focus electrode 5 and the fourth focus electrode 8, and the focus voltage VF is applied to the third and fifth focus electrodes 7 and 9. A parabolic type dynamic focus voltage VFd equal to or higher than the deflection signal is applied, and a high-voltage enowood voltage VE is applied to the final acceleration electrode 10. (V1 <V2 <VF≤VFd <VE)

The electron gun provided with the dual quadrupole lens as described above has a problem that the effect is insufficient because the size of the electron beam pass through the quadrupole effect can not be reduced due to problems in the assembly of the parts.

On the other hand, in order to improve the assemblability, the HI-BI potential focus method in which the focus performance is worse than the UNI-BI potential focus method is applied, or the uni-by potential focus method is used. Although the method of dividing the focus electrode of 1 to improve the quadrupole effect is used, all of the above methods have a problem that the dynamic parabola voltage increases with the problem that the focus voltage rises. This problem is particularly acute in large color color cathode ray tubes for high-definition televisions.

And another example of an electron gun for conventional colored cathode ray tubes is disclosed in US Pat. No. 4,814,670. In the disclosed electron gun, three longitudinal electron beam through-holes 12 are formed on the emission side of the first focus electrode 11 forming the quadrupole lens, and correspondingly installed in the quadrupole lens. On the incidence side surface of the second focusing electrode 13 forming the cross-section, an electron beam passage hole 14 having a horizontal shape in which three electron beams pass through is formed. A constant focus voltage VF is applied to the first focus electrode 11, and a dynamic focus voltage VD is applied to the second focus electrode 13 in synchronization with a deflection signal. Such a conventional electron gun does not solve the above problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an electron gun for color cathode ray tubes with improved horizontal line uniformity at the periphery of the screen.

In order to achieve the above object, according to the present invention, the cathode, the control electrode and the screen electrode constituting the pre-triode part, and the first to third focus electrodes respectively formed between the first and second quadrupole lenses And a final acceleration electrode formed adjacent to the third focus electrode to form the main lens with the third focus electrode, wherein the electron gun of the focus electrode constituting the first quadrupole lens comprises: An electron gun for a color cathode ray tube is provided, characterized in that the horizontal direction of the formed electron beam through holes and the length in the vertical direction are smaller than the diameter of the circular electron beam through holes formed in the electrode member of another adjacent electrode.

According to another feature of the invention, the electron beam through hole formed in the electrode member of the focus electrode constituting the first quadrupole lens is a quadrangle in the longitudinal direction and a quadrangle in the transverse direction.

According to another feature of the invention, the electron beam through hole formed in the electrode member of the focus electrode constituting the first quadrupole lens is formed by combining a square and a circle in the longitudinal direction, and a combination of a square and a circle in the transverse direction. .

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

5 shows the overall structure of the electron gun for color cathode ray tube according to the present invention. The overall structure of the electron gun for color cathode ray tube according to the present invention is similar to that shown in FIG.

Referring to the drawings, the electron gun comprises the cathode 21, the control electrode 22, and the screen electrode 23 forming the pre-triode, and the first, second, third and fourth forming the auxiliary lens and the first and second quadrupole lenses. And a fifth focusing electrode 24, 25, 26, 27, 28 and adjacent to the fifth focusing electrode 28 to form a main lens including a focus lens and a convergence lens. The final accelerating electrode 29 is provided. Each of the electrodes has an electron beam through hole in which three electron beams pass through, or three electron beams pass through, in line.

Meanwhile, the third focus electrode 26 is formed of two electrode members 26a and 26b in which cup and plate electrode members are sequentially arranged, and the fourth focus electrode 27 also includes two cup electrode members 27a, 27b), and the fifth focus electrode 28 is formed of three electrode members 28a, 28b, and 28c so as to have a shape in which an internal electrode is installed inside the plate and cup.

In addition, a predetermined voltage is applied to each of the electrodes. A first constant voltage V1 is applied to the control electrode 22, and a higher than the first constant voltage is applied to the screen electrode 23 and the second focus electrode 25. The second constant voltage V2 is applied. A focus voltage VF higher than the second constant voltage is applied to the first and fourth focus electrodes 24 and 27, and the focus voltage VF is applied to the third and fifth focus electrodes 26 and 28. A parabola type dynamic focus voltage VFd that is equal to or higher than the deflection signal is applied, and a high voltage enowood voltage VE is applied to the final acceleration electrode. (V1 <V2 <VF≤VFd <VE)

The application of the voltage to each of the electrodes is not limited to the above embodiment, and any configuration can be used as long as the electron beam can be focused by forming at least two quadrupole lenses.

In the dynamic focus electron gun for the color cathode ray tube according to the present invention configured as described above, the first quadrupole lens is disposed between the electrode member 26b of the third focus electrode 26 and the electrode member 27a of the fourth focus electrode 27. And a second quadrupole lens is formed between the electrode member 27b of the fourth focus electrode 27 and the electrode member 28b of the fifth focus electrode 28. The third and fifth focus electrodes 26 and 28 are electrodes to which a dynamic focus voltage is applied, and the fourth electrode 27 corresponds to an electrode to which the focus electrode is applied.

According to a feature of the invention, the longitudinal direction of the electron beam through holes formed in the electrodes constituting the first quadrupole lens, and the size of the longitudinal direction is formed smaller than the diameter of the circular electron beam through holes formed in the other electrodes. This will be described in more detail with reference to the drawings.

6 schematically illustrates an exploded perspective view of a third focus electrode and a fourth focus electrode forming a first quadrupole lens.

Referring to the drawings, a circular electron beam through hole 71 is formed in the cup-shaped electrode member 26a of the third focus electrode 26, and an elongated shape is formed in the plate-shaped electrode member 26b of the third focus electrode 26. A rectangular electron beam through hole 72 is formed. The cup-shaped electrode member 26a and the plate-shaped electrode member 26b of the third focus electrode 26 are welded to each other. On the other hand, in the cup-shaped electrode member 27a of the fourth focus electrode 27 (FIG. 5), a rectangular electron beam through hole 73 formed in a horizontal shape is formed.

Although not shown in the figure, a circular electron beam through hole is formed in the other electrode as well as the cup-shaped electrode member 26a of the third focus electrode 26. More specifically, for example, the control electrode 22, the screen electrode 23, and the first focusing electrode 24 and the second focusing electrode 25 illustrated in FIG. 5 may be formed.

Here, the circular electron beam through hole 71 formed in the cup-shaped electrode member 26a of the third focus electrode 26 has a diameter of P1 as shown in the figure. In addition, the horizontal length of the elongated electron beam through hole 72 formed in the plate-shaped electrode member 26b of the third focus electrode 26 was denoted by H1, and the vertical length was denoted by V1. The horizontal length of the electron beam passing hole 73 of the cup-shaped electrode member 27a of the fourth focus electrode 27 was represented by H2, and the vertical length was represented by V2.

According to a feature of the present invention, the horizontal length H1 and the vertical length H of the rectangular electron beam passing hole 72 formed in the plate-shaped electrode member 26b of the third focus electrode forming the first quadrupole lens V1) is formed to be equal to or smaller than the diameter of the circular electron beam through hole formed in the other electrode. More specifically, the horizontal length H1 and the vertical length V1 of the rectangular electron beam passing hole 72 formed in the plate-shaped electrode member 26b of the third focus electrode are the cup-shaped electrode members of the third focus electrode. It is formed smaller than or equal to the diameter P1 of the circular electron beam through hole 71 formed in 26a. That is, P1 ≥ H1, V1 has a relationship.

In addition, the horizontal length H2 and the vertical length V2 of the rectangular electron beam passing hole 73 formed in the cup-shaped electrode member 27a of the fourth focus electrode forming the first quadrupole lens are also applied to the other electrodes. It is formed smaller than the diameter of the formed circular electron beam through hole, for example, is formed smaller than or equal to the diameter (P1) of the circular electron beam through hole 71 formed in the cup-shaped electrode member 26a of the third focus electrode. . That is, P1 ≥ H2, V2 has a relationship.

In the example shown in FIG. 6, the electron beam passing holes of the electrode members forming the first quadrupole lens are formed in a quadrangular shape, but in another example, the electron beam passing holes may be formed in other shapes. Even in this case, the length in the vertical direction and the horizontal direction is formed to be smaller than or equal to the diameter of the circular electron beam passing hole formed in the other electrode member. For example, the electron beam through hole formed in the electrode member forming the first quadrupole lens may be a combination electron beam through hole made of a combination of a rectangle and a circle.

7 illustrates an example in which an electron beam through hole formed of a combination of a rectangle and a circle is formed in the electrode members forming the first quadrupole lens. The example shown in FIG. 7 is basically similar to that shown in FIG. 6, wherein like elements are denoted by like reference numerals.

Referring to the drawings, a circular electron beam through hole 71 is formed in the cup-shaped electrode member 26a of the third focus electrode 26, and an elongated shape is formed in the plate-shaped electrode member 26b of the third focus electrode 26. An electron beam through hole 74 formed by combining a square and a circle is formed. The cup-shaped electrode member 26a and the plate-shaped electrode member 26b of the third focus electrode 26 are welded to each other. On the other hand, in the cup-shaped electrode member 27a of the fourth focus electrode 27 (FIG. 5), an electron beam through hole 75 having a combination of a square and a circle formed in a horizontal shape is formed.

Here, the circular electron beam through hole 71 formed in the cup-shaped electrode member 26a of the third focus electrode 26 has a diameter of P1 as shown in the figure. In addition, the horizontal length of the combined electron beam through hole 74 formed in the plate-shaped electrode member 26b of the third focus electrode 26 was denoted by H1, and the vertical length was denoted by V1. The horizontal length of the combined electron beam through hole 75 of the cup-shaped electrode member 27a of the fourth focus electrode 27 was denoted by H2, and the vertical length was denoted by V2.

According to a feature of the invention, the horizontal length H1 and the vertical length V1 of the combined electron beam through-hole 72 formed in the plate-shaped electrode member 26b of the third focus electrode forming the first quadrupole lens. ) Is smaller than or equal to the diameter P1 of the circular electron beam passing hole 71 formed in the cup-shaped electrode member 26a of the third focus electrode. That is, P1 ≥ H1, V1 has a relationship.

In addition, the horizontal length H2 and the vertical length V2 of the combined electron beam through hole 75 formed in the cup-shaped electrode member 27a of the fourth focus electrode forming the first quadrupole lens are also the third. It is formed smaller than or equal to the diameter P1 of the circular electron beam through hole 71 formed in the cup-shaped electrode member 26a of the focus electrode. That is, P1 ≥ H2, V2 has a relationship.

Shown in FIG. 8 is a schematic partial cutaway perspective view of a color cathode ray tube equipped with an electron gun as described above.

Referring to the drawings, the color cathode ray tube 50 is a panel 51 formed on the inner surface of the fluorescent film 51a formed of a red or blue green phosphor formed in a dot or stripe pattern, and the panel 51 is sealed to the panel 51. A funnel 52 having a neck portion 52a and a cone portion 52b, an electron gun 60 mounted on the neck portion 52a to excite the fluorescent film 51a, and the funnel 52 And a deflection yoke 53 mounted over the neck portion 52a and the cone portion 52b. The electron gun 60 is formed according to the features of the present invention. With the above configuration, the intensity of the first quadrupole lens becomes stronger, thereby reducing the cross-section of the electron beam in the main lens and the lens formed in the deflection yoke, resulting in less spherical aberration, resulting in less distance from the shop. It will be longer. In other words, the image becomes under focus without image formation on the screen, and thus the vertical diameter of the electron beam is increased, and the difference in the cross-sectional size of the electron beam at the center and the periphery is reduced, thereby improving the horizontal line uniformity.

The electron gun for color cathode ray tube according to the present invention can improve the horizontal uniformity by forming the horizontal direction and the vertical length of the electron beam through hole formed in the electrode member forming the first quadrupole lens to be smaller than the diameter of the adjacent circular electron beam through hole. There is an advantage that it can. That is, as shown in FIG. 9A, the width of the horizontal line decreases toward the periphery of the screen in the conventional color cathode ray tube. As shown in FIG. 9B, the width of the horizontal line is uniform in the color cathode ray tube of the present invention.                     

Although the present invention has been described with reference to the embodiments illustrated in the drawings, these are only examples, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the present invention should only be limited by the appended claims.

Claims (3)

A cathode, a control electrode, a screen electrode, a first to third focus electrode each having first and second quadrupole lenses forming therebetween, and adjacent to the third focus electrode; In the electron gun for a color cathode ray tube comprising a final acceleration electrode constituting the third focus electrode and the main lens, The horizontal and vertical lengths of the electron beam through holes formed in the electrode member of the focus electrode constituting the first quadrupole lens are smaller than the diameters of the circular electron beam through holes formed in the electrode member of the other electrode. Tolerance gun. The method of claim 1, The electron beam passing hole formed in the electrode member of the focus electrode constituting the first quadrupole lens is a rectangular in the longitudinal direction and a quadrangle in the transverse direction. The method of claim 1, The electron beam passing hole formed in the electrode member of the focus electrode constituting the first quadrupole lens has a shape in which a square and a circle in the longitudinal direction are combined, and a square and a circle in the lateral direction are formed in combination.

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