KR100513012B1 - Electron gun of color cathode ray tube - Google Patents

Abstract

The present invention relates to an electron gun for color cathode ray tubes. The electron gun for a color cathode ray tube of the present invention is a control electrode having a horizontal electron beam passing hole, an acceleration electrode having a horizontal depression in the first acceleration / focusing electrode opposing surface, and an elongated electron beam passing hole on the opposing surface of the acceleration electrode. A triode comprising a first accelerating / focusing electrode having a lateralization ratio of the main lens incident beam mirror of 4.0 to 6.0; A cathode-side main lens forming electrode comprising one rim common to the R, G, and B electron beams and the electrostatic field control electrode body positioned partially retracted here, and one rim common to the three electron beams and a pair of horizontal directions A main lens comprising an anode-side main lens forming electrode including an electrostatic field control electrode body consisting of plate electrodes facing each other; Characterized in that configured to include.

Description

Electron gun for color cathode ray tube {ELECTRON GUN OF COLOR CATHODE RAY TUBE}

The present invention relates to an electron gun for color cathode ray tubes.

As shown in FIG. 1, the color cathode ray tube includes a panel 30 having a fluorescent screen-screen 10 coated with R, G, and B phosphors on a front inner surface thereof, and a shadow mask 20 having a color screening function. It consists of a funnel 40 sealingly coupled with 30 and having a tubular neck portion 41 formed rearward. An electron gun 50 is mounted inside the neck portion 41 of the funnel 40, and a deflection yoke 60 is coupled to the outside to deflect the electron beam emitted from the electron gun 50 in horizontal and vertical directions.

The three R, G, and B electron beams 70 emitted from the electron gun 50 are focused and accelerated by the electrodes constituting the electron gun 50, and are deflected appropriately in the horizontal and vertical directions by the deflection yoke 60 to form a fluorescent surface. Landing at the predetermined position (10) to excite each phosphor to display an image.

The electrodes of the in-line electron gun for the color cathode ray tube are spaced at regular intervals from each other so as to be perpendicular to the path through which the electron beam 70 passes so that the electron beam generated from the cathode can be controlled in a constant intensity to reach the screen. It is located.

The conventional electron gun has a control electrode having a circular or elongated electron beam through hole, an acceleration electrode having a horizontally-shaped slot on the opposite surface of the first acceleration and focusing electrode, and the lateralization ratio of the main lens incident beam diameter (H). / V) tripolar portion having a structure of about 200% to 300%; A rim common to the three R, G, and B electron beams, wherein the main lens comprises an electrostatic field control electrode body positioned partially retracted; According to the conventional structure of the electron gun, the deterioration of the vertical spot due to the deflection magnetic field is increased, so that a dynamic lens for the separate correction is required, and the structure of the electron gun is added due to the addition of such an additional electrode. As a result, the productivity and workability of the electron gun manufacturing process and the increase of the number of parts increase, and the price increases.

The structure of the conventional electron gun, its operation, and the problems thereof will be described in more detail with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view schematically illustrating a configuration of a general inline electron gun. The first electrode 510, which is a common lattice of three independent cathodes 500 and three cathodes 500 disposed at a predetermined distance from the anode, is shown in FIG. Is provided. The second electrode 520, the third electrode 530, the fourth electrode 540, the first electrode 550A of the fifth electrode, and the fifth electrode disposed at predetermined intervals from the first electrode 510. The electrodes are arranged in the order of the second electrode 550B and the sixth electrode 560. The sixth electrode 560 is provided with a shield cup 570 with B.S.C attached to serve to fix the electron gun to the neck portion of the tube while electrically connecting the electron gun and the tube.

Looking at the action of the electron gun configured as shown in FIG.

First, electrons are emitted from the cathode 500, and the electron beam is controlled by the first electrode 510, which is a control electrode, and accelerated by the second electrode 520, which is an acceleration electrode.

Subsequently, the electron beam is partially focused and accelerated by a shear focusing lens formed between the second electrode 520, the third electrode 530, the fourth electrode 540, and the first electrode 550A of the fifth electrode. As the electron beam is deflected between the first electrode 550A of the fifth electrode and the second electrode 550B of the fifth electrode, a dynamic lens having a variable action of the lens is formed to improve vertical focus deterioration when deflected toward the periphery of the screen. The electron beam is mainly focused and accelerated by the second electrode 550B of the fifth electrode, which is also called a focus electrode, which is a main lens forming electrode, and the sixth electrode 560, which is also called an anode electrode, and the outer beams R and B are center beams. (G) converges to the convergence action. In this manner, the three electron beams finally emitted from the electron gun pass through the shadow mask 20 and collide with the fluorescent surface 10 to emit light.

FIG. 3A illustrates the shape of the electron beam through hole 511 of the first electrode 510, which represents the shape of a circular hole. 3B shows another shape of the electron beam through hole 512 of the first electrode 510, which represents the shape of an elongated ball. FIG. 3C shows the shape of the electron beam through hole 521 of the second electrode 520 of the second electrode 520. In this case, it is a shape of a horizontal ball having a depression. FIG. 3D illustrates the shape of the electron beam through hole 531 on the second electrode 520 side of the third electrode 530. In this case, the shape of the circular hole is represented.

Fig. 4 is a view showing a main lens structure of a conventional electron gun, in which a race track-shaped rim portion in which opposing surfaces of the focus electrode 550B and the anode electrode 560 forming the main lens are common to the three electron beams ( Electrostatic field control electrode bodies 553 and 563, which are plate electrodes having three circular through-holes 552 and 562 formed by retreating from the rim to a predetermined interval in the rim, are formed inside the electrode. The effect of enlarging the main lens is obtained.

In addition, as shown in FIG. 3, the three-pole portion and the prefocus portion of the conventional electron gun are circular or spaced apart from the first electrode 510 having vertical holes smaller than the vertical length 511 and 512. The second electrode 520 having a ball having a hole and having a horizontal depression 521 opposite to the third electrode 530 forms a tripolar lens.

In addition, the third electrode 530 having the second electrode 520 and the circular hole 531 forms one prefocus lens, and the third electrode 530, the fourth electrode 540, and the fifth electrode The first electrode 550A forms an additional prefocus lens. The voltage applied to each electrode is a ground voltage, that is, 0 V at the first electrode 510, a voltage of about 400 to 800 V at the second electrode 520 and the fourth electrode 540, and a third electrode 530. ) And a first static focus voltage of about 5000 to 8000 V is applied to the first electrode 550A of the fifth electrode.

Among the design characteristics of the electron gun described above, the factors affecting the spot size on the screen include lens magnification, spatial charge repulsion, and spherical aberration characteristics of the main lens. Among them, the spot diameter D _x due to the lens magnification has the greatest influence on the object point size determined by the lens action of the electron gun triode and the prefocus portion.

In this case, the object size is most closely related to the pore size of the first electrode 510. The smaller the pore size is, the smaller the object size can be obtained. The electron beam after passing through the tripolar and prefocus lenses is As the advancing angle (α; divergence angle, see Fig. 9A) is increased, a small object size can be obtained, so that a small spot diameter can be realized on the screen.

Next, the space charge repulsion force is an enlarged spot diameter due to mutual reaction and collision between electrons in the electron beam, and it is advantageous to design the divergence angle to be large in order to reduce the spot diameter (D _st ) due to space charge repulsion force. .

On the other hand, the spherical aberration characteristic of the main lens refers to the enlargement of the spot diameter (D _ic ) due to the difference in focal length between the electrons passing through the paraxial axis of the lens and the electrons passing through the circular axis, which is opposite to the space charge repulsion. If the divergence angle incident on the main lens is small, a smaller spot diameter can be realized on the screen.

Therefore, in view of these factors, the spot diameter D _t on the screen is generally expressed by the sum of three elements as shown in the following equation.

 In particular, as a method of reducing spherical aberration while reducing space charge repulsion, the best method is to enlarge the main lens and reduce the magnification of the spot due to spherical aberration even when an electron beam with a large divergence angle α is incident. The space charge repulsion afterwards can also be reduced, enabling small spots on the screen.

On the other hand, the problem of deflection defocusing of spots around the screen caused by the use of self-convergence non-uniform magnetic field deflection yoke, except for the factors affecting the spot diameter on the screen, is also a major factor in the deterioration of focus on the screen. to be.

Fig. 5A shows a lens and on-screen spot when deflecting the screen periphery of an electron gun without a conventional dynamic lens, and Fig. 5B shows a lens and on-screen spot when deflecting a screen periphery of an electron gun with a conventional dynamic lens added. Is showing.

As shown in Fig. 5A, the deflection yoke deflecting magnetic field deflects the electron beam while acting as a lens for diverging in the horizontal direction, and focusing in the vertical direction, causing the spot to be over-focused in the vertical direction, thereby causing a hollow on the screen. Phenomenon occurs.

In order to reduce such a problem, the electron beam shape before entering the main lens in the electron gun tripolar and prefocus lens designs is configured with a horizontal beam 71 as shown in FIG. 6A. 6a, 6b, and 6c schematically show the characteristics of the conventional electron gun triode, FIG. 6a shows the horizontal (H) electron beam radiation characteristics, FIG. 6b shows the vertical (V) electron beam radiation characteristics, and FIG. 6c passes through the three pole portions. The shape of the electron beam afterwards is shown schematically, respectively.

However, as described above, when the lateralization ratio of the electron beam is increased in order to reduce deflection defocusing, the divergence angle α becomes too small in the vertical direction, resulting in an increase in the vertical object spot size, thereby increasing the vertical spot diameter on the screen. It may have a growing problem.

Accordingly, in the conventional electron gun, as shown in FIGS. 6A and 6B, the pore diameter of the first electrode 510 is substantially the same as the horizontal and vertical, and the circular shape of the second electrode 520 is formed in the circular shape of the second electrode 520, so that the crossover ( 72 and a cross-shaped depression 521 is formed in the direction of the third electrode 530 of the second electrode 520 to form a mutually asymmetric lens with the circular hole 531 of the second electrode side of the third electrode. In this case, the horizontal scaling ratio (H1 / V1; 33) of the electron beam before incident on the main lens is lengthened by about 1.5 to 2.5.

As a result, the spot deterioration due to deflection defocusing is partially reduced while the horizontal divergence angle is increased, and the spherical aberration due to the increase in the horizontal divergence angle is reduced while forming a large diameter main lens as shown in FIG. Increasing the aperture, and in particular, the aperture of the main lens is slightly larger than the vertical (Φ8.2mm) horizontally (Φ10.2mm) to compensate for the increase in the horizontal spherical aberration.

In addition, as shown in FIG. 5B, the vertical hollow occurrence phenomenon at the periphery of the screen due to the deflection defocusing is as shown in FIG. 7 when the electron beam is deflected, as shown in FIG. 8. (V) The first electrode 550A of the fifth electrode to which a constant focus voltage is applied by applying a dynamic focus voltage including a dynamic parabolic wave that changes according to the deflection to the second electrode 550B of the fifth electrode of the electron gun. In contrast to the defocusing magnetic field effect caused by deflection yoke, a dynamic lens capable of compensating can be formed to achieve excellent focus in the entire area of the screen.

For reference, a method for calculating the main lens aperture may be described. As shown in the schematic diagram of FIG. 9A, an electron beam emitted from one source point passes through the main lens, and then the angle of the electrons R and the angle of focusing the electrons. (b) is drawn on both axes as shown in Fig. 9b, and the aperture of the large-diameter main lens is measured to some extent compared to the radius and angle when the electrodes having mutually circular holes pass through the mutually opposite circular lenses. Find out if this applies.

The conventional electron gun described so far requires a dynamic lens for compensation of deflection defocusing, and the number of electrodes of the electron gun is increased because the addition of an electrode to which a dynamic focus voltage is applied is required to form the dynamic lens.

Then, according to the needs of the dynamic voltage, a circuit on the chassis for forming a dynamic focus voltage including the dynamic parabolic waveform shown in FIG. 8 is required. Therefore, the conventional electron gun has a problem that the circuit price of the chassis increases with the price of the electron gun itself.

That is, in the electrode forming the triode, the prefocus lens and the main lens of the electron gun for the color cathode ray tube, the dynamic focus is added as needed to improve the focus on the screen due to the high definition and the use of the high frequency. In this case, the price increase is caused by the formation of the dynamic voltage and the addition of the electrode of the electron gun.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron gun for a color cathode ray tube, which does not require the formation of a dynamic lens and can realize excellent focus characteristics without a dynamic voltage.

It is still another object of the present invention to provide a control electrode having a transverse electron beam through hole, an acceleration electrode having a transverse slot on the opposite surface of the first acceleration and focusing electrode, and / or an elongated shape on the opposite surface of the acceleration electrode. A first acceleration / concentration electrode having an electron beam through hole, and a triode having an enlarged lateral ratio of the incident lens diameter of the main lens; A cathode-side main lens forming electrode comprising one rim common to R, G and B three electron beams and an electrostatic field control electrode body positioned partially retracted therein, one rim common to the three electron beams and a pair of horizontal directions A main lens including an anode-side main lens forming electrode formed of a plate-shaped electrode; To provide an electron gun for a color cathode ray tube consisting of.

A further object of the present invention is to configure the control electrode in a horizontal shape, and to configure the main lens as the distance between the electrostatic field control electrode body and the central hole and the outer hole satisfying the R, G, and B convergence requirements (s1, s2). By optimizing), it is to provide an electron gun for color cathode ray tube that enables excellent focus even with a small dynamic waveform even when a dynamic lens is not formed or a dynamic lens is formed.

Electron gun for the color cathode ray tube of the present invention for achieving the above object is a control electrode having a transverse electron beam through hole; And a cathode side electrode of the main lens forming electrode composed of a rim and an electrostatic field control electrode body, and an anode side electrode of the main lens forming electrode composed of a rim and a pair of horizontal plate-shaped electrodes.

In addition, in the electron gun for color cathode ray tube of the present invention, the lateralization ratio (H / V) of the control electrode is selected within at least 1.7 to 2.5, or preferably 200% or more.

In addition, in the electron gun for a color cathode ray tube of the present invention, the acceleration electrode of the triode has a horizontal slot, the acceleration electrode side of the first acceleration / focus electrode has an elongated shape, or the acceleration electrode has a horizontal depression It has a slot, characterized in that the ball shape of the first acceleration / focusing electrode has an elongated shape.

Also, in the electron gun for the color cathode ray tube of the present invention, the center distance between the center hole and the outer hole of the electrostatic field control electrode body having three balls among the main lens forming electrodes is the center between the center hole and the outer hole of the electrode facing the acceleration electrode and the acceleration electrode. It is characterized by being smaller than the distance.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the electron gun for color cathode ray tube of the present invention.

FIG. 10 is a view showing the configuration of the electron gun of the present invention, showing a simple electron gun without the first electrode of the third electrode, the fourth electrode, and the fifth electrode. That is, an electron gun having a simple structure including the cathode 500, the first electrode 510, the second electrode 520, the second electrode 550B of the fifth electrode, the sixth electrode 560, and the shield cup 570. Is showing.

Figure 11 shows an embodiment of the electron beam through hole of the first electrode 510 in the electron gun according to the present invention. In the electron gun of the present invention, as shown in FIG. 11, the ball shape of the first electrode 510 has a horizontal shape having a smaller vertical V than the horizontal H. As shown in FIG. The horizontally shaped electron beam through hole may have a shape of a rectangular electron beam through hole 513 in which a circular ball extends in a horizontal direction, or a shape of a square electron beam through hole 514 with rounded corners. The lateralization ratio (H / V) of the electron beam through holes 513 and 514 of the first electrode 510 is preferably selected within a range of 1.7 to 2.5 so as to satisfy the focus characteristic. It is especially preferable to have a rate of lateralization of at least 200% or more.

12A and 12B show the shape of the electrode ball of the prefocus unit in the electron gun according to the present invention. FIG. 12A shows that the electron beam pass-through hole of the fifth electrode 550B of the second electrode is composed of a horizontal hole having a depression, and FIG. 12B shows the electron-beam pass-hole of the second electrode side of the fifth electrode 550B as an elongated ball. It shows what is configured.

That is, as shown in FIGS. 12A and 12B, the second electrode has a circular ball similar to a conventional electron gun and a horizontal depression 522 toward the fifth electrode side, and the second electrode side hole 532 of the fifth electrode is formed as shown in FIGS. It consists of an elongate shape. The depression 522 of the second electrode and the longitudinal hole 532 of the fifth electrode may be configured simultaneously with each other according to the degree of lateralization of the electron beam, or may be designed to be used respectively.

Finally, as shown in Fig. 13, the main lens of the present invention has a rim portion 551 common to three race-beam-shaped electron beams and an electrostatic field control electrode body 553 having three balls 522 positioned at a predetermined interval. And a sixth electrode having a pair of electrostatic field control electrode bodies 564 having a pair of mutually opposite forms.

In particular, the distance S2 between the central hole and the outer space of the electrostatic field control electrode body 553 positioned at the second electrode 550B of the fifth electrode is equal to the distance S1 between the central hole and the outer space of the second electrode 520. It should be formed small compared to. This is because the electrostatic field control electrode body having three balls is not formed in the sixth electrode 560 like the conventional electron gun main lens. That is, conventionally, three electron beam through holes 562 are formed in the electrostatic field control electrode body 563 as shown in FIG. 4, but in the present invention, as shown in FIG. This is because the electrostatic field control electrode body 564 is formed.

Therefore, in this case, since the action of the convergence lens that collects the outer beam toward the center beam is weakened, a strong convergence lens must be formed at the second electrode 550B of the fifth electrode. To this end, the electrostatic field control electrode body 564 of the sixth electrode 560 is formed in a 'c' shape to be fixed and is attached to the shield cup 570, which is attached to the shield cup 570 The site forms a shape having three electron beam through holes 571.

The electron gun for the color cathode ray tube of the present invention configured as described above can realize the equivalent focus characteristics without adding the dynamic lens, and even when the dynamic lens is used, excellent focus performance can be realized with a small dynamic voltage.

That is, in order to solve the problem of increasing the price of the electron gun and the chassis due to the need of the dynamic lens, which is a problem of the conventional main lens, the shape of the electron beam through holes 513 and 514 of the first electrode 510 is 1.7 to 2.5. As shown in Fig. 15, the first electrode pore diameter V in the vertical direction is minimized as shown in FIG. 15, thereby exhibiting a small vertical object spot size. Will have Therefore, it compensates for the increase in the size of the object, and the small electron beam diameter at the time of incidence of the main lens drastically reduces the influence of the deflection defocusing magnetic field in the deflection yoke, thereby realizing excellent vertical spot characteristics in the entire screen without a dynamic lens.

In the horizontal direction, the pore size H of the first electrode 510 is large, so that an increase in the size of the object point is expected. However, as shown in FIG. 16A, the cross-over is not formed in the horizontal direction. By minimizing the negative lens focusing force, an electron beam having a large divergence angle can be formed, thereby compensating for the enlargement of the size of the object due to the increase in the pore size of the first electrode 510.

Figure 16a schematically shows the horizontal (H) electron beam radiation characteristics in the electron gun tripolar characteristics of the present invention, Figure 16b schematically shows the vertical (V) electron beam radiation characteristics in the electron gun tripolar properties of the present invention, Fig. 16C schematically shows the shape of the electron beam after passing through the triode. As shown in Fig. 16A, the crossover is not formed in the horizontal (H) direction in the present invention.

On the other hand, a large divergence angle in the horizontal direction causes a problem of increasing spherical aberration in the main lens. Therefore, in the present invention, by changing the shape of the electrostatic field control electrode body 564 of the sixth electrode 560 so as to maximize the horizontal aperture of the main lens, the horizontal lens aperture is increased to Φ12.0 mm as shown in FIG. 9B to compensate. On the contrary, the vertical main lens aperture reduced to φ7.6 mm has little effect on spherical aberration due to the small electron beam diameter upon incidence of the main lens, and thus there is no increase in the vertical spot diameter on the screen.

As shown in Fig. 6C, the lateralization ratio (H2 / V2) of the electron beam at the time of incidence of the main lens of the present invention is 4.0 to 6.0, and the lateral diameter of the first electrode 510 is increased with the lateralization of the first electrode 510 for such lateralization. It is necessary to form an asymmetric prefocus lens such as the horizontal depression 522 of the second electrode 520 and the second electrode side longitudinal hole 532 of the second electrode 550B of the fifth electrode as shown in FIG. 12A. When it is necessary to increase the lateralization rate of the symmetry, the asymmetry may be greatly increased by simultaneously using the depression 522 of the second electrode 520 and the longitudinal hole 532 of the fifth electrode. If it is not necessary to increase greatly, the depression 522 of the second electrode 520 or the longitudinal hole 532 of the fifth electrode may be used alone.

Also, the reason why the ratio of the H / V of the electron beam through hole of the first electrode 510 is suitable for the level of 1.7 to 2.5 is related to the horizontal spot size on the screen according to the first electrode hole thickening ratio shown in FIG. As shown, when the horizontal ratio is less than 1.7, the electron beam forms a crossover in the horizontal direction, and the horizontal object point size becomes large. When the horizontal ratio is larger than 2.5, the horizontal first electrode 510 has a pore diameter. This is because the horizontal spot diameter on the screen is enlarged due to an increase in the size of the object caused by the enlargement of the lens, thereby deteriorating the focus.

In addition, the present invention is a vertical divergence angle of the electron beam affected by the tripolar lens and the prefocus lens as shown in Figure 15 is very small, the horizontal divergence angle is so large that the conventional electron gun that additionally focuses the electron beam as in the prior art There is no need for an additional prefocus lens formed on the first electrode of the third electrode, the fourth electrode and the fifth electrode.

In the main lens of the present invention, as shown in FIG. 14, the electrostatic field control electrode body having three balls capable of distinguishing and converging three electron beams is not formed on the sixth electrode 560, but as described above, the second lens of the fifth electrode is formed. The distance S2 between the central hole and the outer hole of the electrostatic field control electrode body 553 of the electrode 550B is centered in the direction of the second electrode 520 of the second electrode 520 and the second electrode 550B of the fifth electrode. By making it smaller than the distance S1 between the ball and the outer space, a convergence lens action can be formed.

18 is a view showing another embodiment of the electron gun for color cathode ray tube according to the present invention. As shown in the present invention, there is no existing third electrode and fourth electrode, but the dynamic lens is disposed on the first electrode 550A of the fifth electrode. To form an electron gun. The internal structure of the electrode of the electron gun is the same as the present invention described so far.

Even in the case of using a dynamic lens as shown in Fig. 18, since the diameter of the vertical electron beam incident on the main lens is smaller than that of the conventional electron gun, the deflection defocusing due to the magnetic field of the deflection yoke is small, which makes it possible to achieve excellent focus even with a small dynamic waveform. It can be implemented to reduce the circuit cost of the chassis.

The present invention eliminates the need for a dynamic lens by greatly increasing the lateralization ratio of the main lens incident electron beam to reduce vertical deflection defocusing due to deflection yoke.

Therefore, it is possible to solve the problem of price increase due to the addition of the electrode of the electron gun itself, which is a problem of the conventional dynamic electron gun, and the circuit price increase of the chassis for implementing the dynamic waveform. In addition, even when a dynamic lens is used, the dynamic voltage can be reduced as compared with the related art, thereby reducing the price of the chassis circuit. In addition, since the third electrode and the fourth electrode of the electron gun are unnecessary, the structure of the electron gun is simplified, thereby improving workability and productivity, and further reducing the price due to the reduction of the electron gun electrode.

In addition, the present invention can further improve the sensitivity of the one-sided hollow due to the center misalignment (alignment misalignment) between the balls of the electron gun triode and prefocus portion electrodes by reducing the vertical electron beam diameter of the main lens incident beam. Has

1 is a view showing the configuration of a color cathode ray tube;

2 is a cross-sectional view showing a conventional electron gun configuration

3A, 3B, and 3C show the shape of an electron beam through hole in an electrode of a conventional electron gun tripolar portion / prefocus portion;

4 is a view showing a conventional electron gun main lens unit configuration

5A and 5B schematically show a lens and a spot shape on a screen when deflecting a periphery of a conventional electron gun screen;

6A, 6B, and 6C schematically show a conventional electron gun tripolar configuration and electron beam radiation;

7 is a diagram schematically showing a screen scanning form of an electron beam;

8 is a parabolic voltage waveform diagram of a conventional dynamic lens unit.

9A and 9B are diagrams schematically showing a method for calculating an electron gun main lens aperture;

Fig. 10 is a sectional view showing the electron gun structure of the present invention.

11 is a view showing the shape of the first electrode ball in the electron gun of the present invention;

12a and 12b are views showing the shape of the prefocus electrode ball in the electron gun of the present invention;

13 is a view showing the configuration of the main lens unit in the electron gun of the present invention;

Fig. 14 is a diagram showing the distance relation between the electrode balls of the main lens unit in the electron gun of the present invention;

15 is a diagram schematically showing a lens and a spot shape on a screen when deflecting the periphery of a screen in the electron gun of the present invention;

16A, 16B, and 16C are diagrams schematically showing a tripolar configuration and electron beam radiation in the electron gun of the present invention.

17 is a view showing a change in the horizontal spot size on the screen according to the horizontal ratio of the first electrode ball in the electron gun of the present invention

18 is a cross-sectional view showing a configuration of an electron gun according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

500: cathode 510: first electrode

520: second electrode 550B: fifth electrode

560: sixth electrode 570: shield cup

513,514,522,532: electrode hole 564: electrostatic field control electrode body

Claims (8)

A shear lens comprising a plurality of cathodes for emitting an electron beam, a tripole portion comprising a control electrode and an acceleration electrode for controlling the radiation amount of the electron beam, at least two or more electrodes serving to focus the electron beam a predetermined amount, and the electron beam An electron gun for cathode ray tubes, wherein an electrode forming a main lens for focusing light on a screen is composed of two electrodes, The ball shape of the control electrode is a horizontal cross-section is larger than the vertical, The main lens forming electrode includes an electrode composed of one authorized rim portion common to three electron beams and an electrostatic field control electrode body having three balls positioned at a predetermined distance from the rim portion, and one authorized rim portion common to the three electron beams and the rim portion. An electron gun for a color cathode ray tube, characterized in that electrodes formed of a plate-type electrostatic field control electrode body composed of a pair of upper and lower sides positioned in a horizontal direction and spaced apart from each other at a predetermined distance from each other face each other at a predetermined distance from each other. The electron gun for a color cathode ray tube according to claim 1, wherein the lateralization ratio (H / V) of the electron beam through hole of the control electrode is 1.7 to 2.5. The electron gun for color cathode ray tubes according to claim 1 or 2, wherein at least one horizontal depression is formed in the acceleration electrode. The electron gun for color cathode ray tubes according to claim 1 or 2, wherein the ball of the electrode facing the acceleration electrode has an elongated shape whose horizontal is smaller than vertical. The center distance between the center hole and the outer hole of the electrostatic field control electrode body having three balls among the main lens forming electrodes is between the center hole and the outer hole of the electrode facing the acceleration electrode. Electron gun for color cathode ray tubes, characterized in that it is smaller than the center distance. The electron gun for a color cathode ray tube according to claim 1 or 2, wherein the transverse ratio of the electron beam when the main lens is incident is 4.0 to 6.0. In the cathode ray tube electron gun consisting of a plurality of electrodes for generating a plurality of electron beams at the cathode and accelerate the electron beam to focus on the fluorescent surface, A control electrode having a transverse electron beam through hole, an acceleration electrode having a transverse depression on the opposite surface of the first acceleration / focus electrode, and a first acceleration / focus electrode having a longitudinal electron beam through hole on the opposite surface of the acceleration electrode. A tripole having a horizontal ratio of 4.0 to 6.0 and including a main lens incident beam mirror; A cathode-side main lens forming electrode comprising one rim common to the R, G, and B electron beams and the electrostatic field control electrode body positioned partially retracted here, and one rim common to the three electron beams and a pair of horizontal directions A main lens comprising an anode-side main lens forming electrode including an electrostatic field control electrode body consisting of plate electrodes facing each other; Electron gun for color cathode ray tube, characterized in that configured to include. 8. The electron gun for a color cathode ray tube according to claim 7, wherein the lateralization ratio (H / V) of the electron beam through hole of the control electrode is 1.7 to 2.5.