KR20010018887A - electon gun for color cathode ray tube - Google Patents

Abstract

PURPOSE: An electron gun for a color cathode-ray tube is provided which reduces the vertical size of an electron beam passage hole of the first electrode controlling generation of hot electrons from an electron emitting material of a cathode to decrease horizontal and vertical sizes of spot with balance. CONSTITUTION: An electron gun for a color cathode-ray tube includes a plurality of cathodes for emitting electron beams, a triode configured of the first and second electrodes for controlling the amount of radiation of the electron beams emitted from the cathodes and accelerating the electron beams to a screen, at least two pre-focus lenses for focusing a predetermined quantity of the electron beams, and at least two electrodes constructing a main lens for focusing the electron beams on the screen. At least one electron beam passage hole(10a) whose horizontal side is longer is formed in the first electrode, and a slot(11b) whose horizontal side is longer is formed around at least one electron beam passage hole among electron beam passage holes(11a) of the second electrode. Otherwise, at least one electron beam passage hole whose horizontal side is longer is formed in the first electrode and at least one electron beam passage hole whose horizontal side is longer is formed in the second electrode.

Description

Electron gun for color cathode ray tube

The present invention relates to an electron gun used in a color cathode ray tube or a high-definition industrial monitor, and more particularly, to a first electrode for controlling generation of hot electrons from an electron emission material of a cathode.

1 is a cross-sectional view of a general color cathode ray tube, the cathode ray tube comprising a panel 1, a fluorescent film 2 coated with red, green and blue phosphors on the inner surface of the panel, and a cone-shaped neck portion 3a. ) Is integrally formed and fixed to the panel, a shadow mask 5 which is installed in close proximity to the inner surface of the panel and serves as color selection of the electron beam 4, and the neck portion 3a of the funnel. ) And a deflection yoke (7) for enclosing the electron beam (4) to scan the electron beam (4) to the screen side, and for deflecting the electron beam emitted from the electron gun in the vertical or horizontal direction.

Each electrode of the electron gun 6 applied to the cathode ray tube is arranged in-line perpendicular to the path through which the electron beam passes so that the electron beam generated from the cathode can be controlled to a constant intensity and reach the screen.

The configuration of the electron gun is described in more detail with reference to FIG. 2 as follows.

FIG. 2 is a schematic view of the electron gun applied to FIG. 1, wherein the electron gun 6 includes three cathodes 9 each having a heater 8 therein and arranged horizontally side by side independently from each other, and a predetermined distance from the cathode is maintained. A first electrode 10 disposed to control hot electrons generated at the cathode, and hot electrons arranged on the surface of the electron emission material (not shown) of the cathode 9 so as to maintain a predetermined distance from the first electrode. A third electrode 12 in the tube axis direction to form a second electrode 11 serving to accelerate and pull out and a electrostatic focusing lens for focusing the electron beam on the fluorescent film 2 coated on the panel 1; The fourth electrode 13, the fifth electrode 14, and the sixth electrode 15 are sequentially arranged at regular intervals, and the shield cup 16 is fixed to the upper portion of the sixth electrode 15. The shield cup has an electron gun 6 and a neck portion 3a electrically connected thereto. Gyeolhae while fixed three B.S.C (Bulb Space Connector) (17) serving to secure the electron gun in the neck portion.

Different voltages are applied to the cathodes 9 so as to obtain a constant current value so that the cut-off voltages are necessarily the same.

Accordingly, the electron gun 6 having the above-described structure generates electrons from the cathode 9 when the heater 8 embedded in the cathode 9 receives power from the stem pin 18 to generate heat, and thus emits electrons. The electron beam 4 to be controlled is controlled by the first electrode 10 and accelerated by the second electrode 11 which is an acceleration electrode.

Thereafter, the electron beam is slightly focused by the prefocus lens 19 formed between the second electrode 11 and the third electrode 12, and then the fifth electrode 14 and the first electrode forming the main lens 20 are formed. The screen is reproduced because the main focus and acceleration through the six electrodes 15 and the shadow mask 5 provided in close proximity to the fluorescent film 2 are color-coded and collide with the phosphor layer to emit phosphors.

As described above, when the electron beam 4 emitted from the electron gun 6 leaves the electron gun and proceeds to the screen side, the deflection yoke 7 installed in the neck portion 3a deflects the electron beam vertically and horizontally over the entire area of the screen. Let it be.

4 and 5 are front views showing the second and third electrodes of the related art, in which the direction perpendicular to the inline is smaller than the inline direction as shown in FIG. 4 on the opposite surface of the third electrode 12 of the second electrode 11. A long depression (hereinafter referred to as a "long slot") 21 is formed, or a direction in which the inline direction is perpendicular to the inline direction as shown in FIG. 5 on the opposite surface of the second electrode 11 of the third electrode 12. A larger longitudinal depression (hereinafter referred to as an "long slot") 22 is formed.

The horizontal slot 21 and the longitudinal slot 22 serve to asymmetrically form a lens formed by a potential difference between the second electrode 11 and the third electrode 12.

The voltage applied to the second electrode 11 is 400 to 1,000 V, and the voltage applied to the third electrode 12 is about 6,000 to 10,000 V.

In order to reduce spherical aberration of the lens in the main lens of the electron gun, as shown in FIG. 3, an opening 23 through which three electron beams pass in common to the opposing surfaces of the fifth electrode 14 and the sixth electrode 15 which face each other is provided. ) 24 are formed respectively, and the electrostatic field control electrode body 25 is formed inside the fifth electrode 14 and the sixth electrode 15, that is, at a point where the predetermined distance is retracted from the openings 23 and 24. (26) are fixed to each other to expand the size of the main lens formed between the fifth electrode 14 and the sixth electrode 15, while the in-line direction is asymmetric main lens with a stronger focusing force than the direction perpendicular to it Since the electron beam leaving the electron gun 6 is deflected by the deflection yoke 7, the deterioration caused by the deflection defocusing phenomenon occurs.

Therefore, when the electron beam 4 is emitted from the cathode 9 in the electron gun 6 having the structure as described above, it is horizontally formed by the horizontal slot 21 formed on the opposing surface of the third electrode 12 of the second electrode 11. Since the lens intensity in the direction becomes smaller than the lens intensity in the vertical direction, the electron beam changes into a horizontal shape in which the horizontal direction is larger than the vertical direction and is incident on the main lens side.

In more detail, the pre-focus lens 19 has a horizontal direction in which the pre-focus lens 19 is horizontally formed by the horizontal slot 21 of the second electrode 11 and the longitudinal slot 22 of the third electrode 12. While the intensity is weakened to focus the electron beam small, the vertical direction causes the electron beam to be horizontally concentrated because the lens intensity is strong to focus largely.

The reason for the horizontal lengthening of the electron beam is to increase the distance in the horizontal direction while decreasing the spherical aberration of the main lens formed between the fifth electrode 14 and the sixth electrode 15 in comparison with the vertical direction. When the focal length in the horizontal direction is formed long so that the focusing distance in the horizontal direction is shorter than in the vertical direction, when the electron beam is deflected by the non-uniform deflection magnetic field by the self-convergence deflection yoke, the non-uniform deflection magnetic field 7 The deflection defocusing caused by the compensation is compensated for.

In addition, the asymmetric prefocus lens 19 formed by the horizontal slot 21 formed on the opposing surface of the third electrode 12 of the second electrode 11 forms an electron beam with a vertical length smaller than the horizontal. It compensates for the horizontalization of the electron beam generated in the periphery of the screen.

Therefore, when such a spot is deflected to the periphery of the screen, the amount to be lateralized is reduced and is formed in a shape similar to a circular shape, thereby improving the focus due to the reduction of the horizontal spot diameter at the periphery of the screen and increasing the vertical spot at the periphery of the screen. This reduces the risk of moiré, which in turn improves the resolution.

However, in order to compensate for the phenomenon that the spot is horizontally enlarged at the periphery of the screen due to the increase in the deflection angle due to the increase in size and the high resolution of the screen and the increase in the horizontal deflection frequency due to the high resolution demand, the spot on the screen must be reduced in the horizontal direction. do.

On the other hand, the solution to the above problems is to reduce the effect of spherical aberration by expanding the effective lens diameter in the main lens unit to increase the size of the electron beam incident on the main lens in the horizontal direction to reduce the space charge repulsion effect between the electron beams By reducing the spot in the horizontal direction on the screen, it is possible to prevent the degradation of the resolution due to the spot lateralization of the periphery of the screen, which is a problem in the large screen.

6 is a graph showing the relationship between the size of the screen spot, the space charge repulsion force and the spherical aberration, and it can be seen that the screen spot is reduced when the space charge repulsion force is reduced or the spherical aberration is reduced.

In order to reduce the horizontal spot as described above, the size of the electron beam incident on the main lens side and the divergence angle of the horizontal electron beam should be enlarged so that the effective lens diameter of the enlarged main lens exerts sufficient effect. The depth of the horizontal slot 21 formed in the opposing surface of the three electrodes 12 had to be set deep, or the width in the horizontal direction had to be widened.

In this case, the divergence angle in the horizontal direction is increased to increase the size of the electron beam incident on the main lens, but the divergence angle in the vertical direction is relatively reduced, so that the vertical spot of the screen cannot be reduced.

In addition, although the thickness around the electron beam through hole of the second electrode 11 can be reduced to increase the divergence angle in the vertical direction and the horizontal direction, the fifth electrode 14 and the fifth electrode 14 can be used to enlarge the effective lens diameter of the main lens. The electrostatic field control electrode bodies 25 and 26 located at a predetermined interval from the opening of the sixth electrode 15 had to be further retracted.

Therefore, in the function of expanding the size of the main lens, it is effective to enlarge the effective lens diameter in the horizontal direction, but the expansion of the effective lens diameter in the vertical direction is relatively insufficient, and there is a limit in reducing the spot in the vertical direction.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem in the related art, and an object thereof is to reduce the vertical pore diameter of the first electrode to reduce the vertical and horizontal diameters of the screen spot in a balanced manner.

According to an aspect of the present invention for achieving the above object, a three-pole portion consisting of a plurality of cathodes for emitting an electron beam, at least two electrodes for controlling the amount of electron beam radiation from the cathode and then accelerated to the screen, and the electron beam An electron gun for a cathode ray tube composed of at least two prefocus lenses comprising at least two parts for focusing a predetermined amount, and at least two electrodes forming a main lens for focusing the electron beam on a screen, wherein at least one of the first electrodes An electron beam through hole is formed in a horizontal shape, and an electron gun for a color cathode ray tube is provided, wherein a slot is formed in a periphery of at least one of the electron beam through holes of the second electrode facing the third electrode.

According to another aspect of the present invention, there is provided a three-pole portion comprising a plurality of cathodes emitting an electron beam, at least two electrodes for controlling the amount of electron beam radiation from the cathode and then accelerating to the screen, and at least for focusing the electron beam at a predetermined amount. In an electron gun for a cathode ray tube composed of two or more prefocus lenses and two or more electrodes forming a main lens for focusing the electron beam on the screen, at least one electron beam passing hole is formed in the first electrode in a horizontal direction. The electron gun for the color cathode ray tube is provided, characterized in that at least one electron beam passing hole is formed in the horizontal shape in the second electrode.

1 is a cross-sectional view of a typical colored cathode ray tube

2 is a schematic view showing the configuration of an electron gun applied to FIG.

3 is a longitudinal sectional view showing a conventional main lens forming electrode;

4 is a front view showing a conventional second electrode

5 is a front view showing a conventional third electrode

6 is a graph showing the relationship between the size of the screen spot, the space charge repulsive force, and the spherical aberration

7 is a front view of a first electrode and a second electrode showing a first embodiment of the present invention;

8 is a front view of a first electrode and a second electrode showing a second embodiment of the present invention;

9 is a front view of a first electrode and a second electrode showing a third embodiment of the present invention;

10A to 10C are beam spot diagrams showing the comparison between the present invention and the prior art.

Explanation of symbols for main parts of the drawings

9 cathode 10 first electrode

10a, 10b: electron beam passing hole 11: second electrode

11b: horizontal slot 11c: electron beam through hole

Hereinafter, the present invention will be described in more detail with reference to FIGS. 7 to 10.

FIG. 7 is a front view of the first electrode and the second electrode according to the first embodiment of the present invention, in which three electron beam through holes 10a having a horizontal shape smaller than the horizontal of the first electrode 10 are formed. On the surface of the second electrode 11 opposite to the third electrode 12, a horizontal slot 11b having a vertical angle smaller than the horizontal is formed around the electron beam through hole 11a.

FIG. 8 shows a second embodiment of the present invention, in which three electron beam through holes 10a having a horizontal shape smaller than horizontal are formed in the first electrode 10, and the second electrode 11 also has a second electrode. Similar to the one electrode, three electron beam through holes 11c each having a vertical shape smaller than horizontal are formed.

In the first and second embodiments, the elongated electron beam through hole 10a formed in the first electrode 10 may be applied to the elliptical hole 10b of the elongated shape as shown in FIG. 9 of the third embodiment. Do.

The first electrode 10 and the second electrode 11 are installed so as to face each other so that a predetermined interval is maintained, and different potentials are applied to the first electrode 10 and 0 V to the first electrode 10 and 260 to 2nd electrode 11, respectively. 10,000 V is applied to form an asymmetric tripolar lens due to the potential difference between them.

The present invention can achieve the horizontal reduction of the spot in the screen as shown in Figure 10a to 10c by the enlargement of the main lens 20, but the vertical reduction is relatively insufficient to enlarge the main lens in the vertical direction Since it is difficult to meet the recent cathode ray tube quality requirements, the vertical dimension of the electron beam emitted from the cathode is reduced by reducing the dimension in the direction perpendicular to the inline direction of the electron beam through holes 10a and 10b formed in the first electrode 10. To overcome the conventional problems by reducing the range of the direction and by reducing the distance of the object.

In addition, the emission range is reduced in the traveling direction of the electron beam and the horizontal slot 11b is formed in the inline direction of the third electrode 12 facing the second electrode 11 so that the electron beam is incident on the main lens 20 side. In this case, the divergence angle in the horizontal direction and the divergence angle in the vertical direction are properly controlled and then incident on the main lens side, thereby reducing the influence of spherical aberration, thereby effectively reducing the vertical spot on the screen.

On the other hand, in the in-line direction of the electron beam through holes 10a and 10b of the first electrode 10, the dimensions in the horizontal direction are kept unchanged to obtain a spot reduction effect due to the expansion of the conventional main lens effective lens. Therefore, the spot on the screen can be reduced in both the vertical and horizontal directions.

Further, when the electron beam through holes 10a and 10b of the first electrode 10 are reduced, a phenomenon in which the load of the cathode 9 is increased occurs, which causes a problem that the life of the cathode ray tube is reduced. In addition to the reduction of the vertical electron beam through-holes, the shape of the electron beam through-holes is improved to a rectangular shape to maximize the radiation area of the electron beams emitted from the cathode, thereby maintaining the lifetime of the cathode as before or shortening the electron beam through-holes. Could be extended.

In addition, as in the second embodiment, the second electrode 11 has a transverse electron beam through hole 10a formed in the inline direction of the first electrode 10 and a transverse electron beam through hole 11c formed in the inline direction. ), The structure of the second electrode 11 is more easily formed, and the productivity and design of the second electrode 11 are further simplified by finely adjusting and expanding the dimension of the horizontal electron beam through hole of the second electrode 11 together. It is possible to improve the margin.

In particular, when the shadow mask passing before the electron beam reaches the phosphor of the screen is an aperture grille or a stripe type, the moiré phenomenon does not need to be considered when designing the cathode ray tube.

As described above, the present invention reduces the dimension of the electron beam passing holes 10a and 10b formed in the first electrode 10 in the direction perpendicular to the inline direction to reduce the vertical range of the electron beam emitted from the cathode 9. It reduces the spot distance and at the same time reduces the divergence from the electron beam propagation direction to enter the main lens, thereby reducing the influence of spherical aberration, and thus reducing the vertical spot on the screen. High resolution can be implemented in.

Claims (3)

A three-pole portion comprising a plurality of cathodes for emitting an electron beam, at least two electrodes for controlling the amount of electron beam radiation from the cathode and then accelerating to a screen, and at least two or more prefocuses for focusing the electron beam in a predetermined amount In the electron beam for cathode ray tube composed of a lens unit and two or more electrodes forming a main lens for focusing the electron beam on the screen, at least one electron beam through hole is formed in the first electrode in a horizontal shape, and the third electrode and An electron gun for a color cathode ray tube, characterized in that a horizontal slot is formed at a periphery of at least one of the electron beam through holes of the opposed second electrode. A three-pole portion comprising a plurality of cathodes for emitting an electron beam, at least two electrodes for controlling the amount of electron beam radiation from the cathode and then accelerating to a screen, and at least two or more prefocuses for focusing the electron beam in a predetermined amount In a cathode ray tube electron gun composed of a lens unit and two or more electrodes forming a main lens for focusing the electron beam on the screen, at least one electron beam passing hole is formed in the first electrode in a horizontal shape, and An electron gun for a color cathode ray tube, characterized in that at least one electron beam passing hole is formed in a horizontal shape. The method according to claim 1 or 2, The electron gun for a color cathode ray tube, characterized in that the electron beam passing hole formed in the first electrode is rectangular.