KR100208168B1 - An electron gun device for a color crt - Google Patents

Abstract

In the present invention, in order to prevent the electron beam from being distorted by deflection aberration in a CPT using a non-uniform magnetic field, a rectangular groove is formed in the G1, G2, and G3 electrodes to make the electron beam form transversely before the main lens is incident and deflected. This is to reduce the aberration to increase the resolution across the screen.

According to the present invention, in the in-line type color cathode ray tube consisting of a portion wood, a first grid, a second grid, a third grid, and a fourth grid sequentially arranged in the screen direction, the electron beam passing through the first grid is described. The shape of the ball 3a is a square shape, and a rectangular groove having a long vertical direction in the direction of the second grid is provided, and the second grid has a first grid 3 in the square electron beam through hole 4a. Direction has a rectangular groove having a long horizontal direction, the third grid has a circular electron beam through hole (5a) and a rectangular groove having a long vertical direction in the second grid direction.

Description

Electron gun for color cathode ray tube

1 is a conventional electron gun structure diagram.

2 is a distortion diagram of an electron beam by a pincushion magnetic field.

3 is a diagram showing the electric pole arrangement and electron lens formation according to the present invention.

4 is a structural diagram of an electron beam through hole according to the present invention.

5 is the spot size on the electron beam guard (H / V) vs. screen before the main lens point incident according to the present invention.

Figure 6 is a spot shape view from the screen of the electron gun according to the present invention.

7 is a cross-sectional view of a second grid of the conventional electron gun.

* Explanation of symbols for main parts of the drawings

101: cathode 103: first grid

104: second grid 105: third grid

103a: electron beam passing hole 103b: groove

107: pincushion magnetic field 110: halo

111: electron beam

The present invention relates to an electron gun for a color cathode ray tube, in which vertical / horizontal rectangular grooves are formed in the first grid, the second grid, and the third grid, so that the electron beam shape before the main lens is incident to the horizontal, It aims to increase the resolution in the entire CRT screen by preventing distortion.

Conventional electron guns for color cathode ray tubes generally have a plurality of in-line integrated grid electrodes in which a plurality of electron beam through holes are perforated in a circle in a horizontal in-line (IN-LINE) on a grid electrode of a flat plate and a flat plane. Main parts are constructed by fusion and fixation with bead glass while maintaining a distance between predetermined grid electrodes by a force of. The plurality of sequentially stacked grid electrodes have a heater 2 as shown in FIG. 1. The first grid electrode 3 and the second grid electrode 4 constituting the electron beam forming region for forming the hot electrons radiated from the cathode 1 as electron beams, and the main beams for narrowly converging the electron beams which are subsequently entered The focusing electrodes 5 constituting the electrostatic focusing lens and the second acceleration and focusing electrodes 6 are arranged in this order.

In addition, depending on the type, a third grid electrode and a fourth grid electrode for inserting shearing may be additionally inserted between the grid electrode constituting the electron beam forming region and the electrode constituting the electrostatic focusing lens to achieve a multi-stage focusing type with enhanced focusing effect. (Not shown in the figure).

In the conventional CRT electron gun, an electron beam is formed through the first grid electrode and the second grid electrode, and the light is focused finely while passing through the main lens formed by the difference between the focusing electrode, the second acceleration, and the voltage applied to the focusing electrode. The beam spot is accelerated to form a beam spot on the screen. At this time, the electron beam passing holes of all the electrodes from the first grid 3 to the second acceleration and focusing electrodes 6 arranged in sequence become circular and close to the long circle, and the deflection yoke When the electron beam reaches the center of the screen of the color cathode ray tube unaffected by the image, the electron beam exits the circular electron gun and is scanned through the entire screen by the deflection magnetic field in the deflection yoke, which is excreted for a predetermined distance from the exit of the electron gun toward the screen. This magnetic field has to focus a plurality of electron beams at one point on the screen. An electron gun in a horizontal, as mentioned standing-emitting the electron beam line, and by a magnetic field generated by the deflection yoke in a non-uniform magnetic field, has been adopted syeolpeu convergence scheme to achieve the goal.

In FIG. 7, reference numeral 14 is an electron beam through hole of the conventional electron gun, and 15 is a recess of the conventional electron gun.

The problem of the prior art configured as described above is that the non-uniform magnetic field can be divided into a pincushion magnetic field 7 and a barrel magnetic field.

The deflection of the electron beam due to the barrel magnetic field during deflection is weak, but the distortion due to the pincushion magnetic field compresses the electron beam in the upper and lower sides, as shown in FIG. Since it acts as a quadrupole component that tensions the electron beam, it is scanned through the deflection region and viewed as a whole in the electron beam spot, and at the same time, it is crushed in a horizontal shape. These electron beams have greatly reduced the resolution of the screen.

In addition, in Japanese Patent Soha 63-232246 and Pyeong 4-10693, a rectangular groove 15 is formed in the second grid around the electron beam passing hole 14 in the direction of the third grid, as shown in FIG. We're improving the spotlight, but we couldn't get enough of it.

This faint halo-shaped horizontal spot forms an electron beam spot consisting of a core portion 9 having a high electron beam density and a halo portion 10 having a low electron beam density, which is a non-uniform magnetic field intensity toward the periphery of the screen. Because of this phenomenon, it becomes more prominent in the periphery of the screen. Because of this phenomenon and the phenomenon of the focus comfort of the electron beam and the distance to the periphery of the screen, the core is increased in the electron beam spot that appears on the screen as the periphery of the color cathode ray tube is increased. 9) the part becomes smaller and the halo 10 becomes larger, which greatly reduces the resolution of the screen.

Accordingly, the present invention has been made to solve the above problems, which is particularly intended to provide an electron gun for a color cathode ray tube which improves the electron beam spot characteristics of the periphery and the center of the screen of the color cathode ray tube to have a uniform spot on the front of the screen. When described in detail based on the accompanying drawings as one as follows.

3 is a perspective view showing specific electrode characteristics of the present invention.

The electron beam accommodates the radiating cathode 101 and the heater 2 therein, and consists of a first grid 103, a second grid 104, a third grid 105, and the like sequentially.

As shown in FIG. 4, the first grid has a square electron beam through hole 103a and a rectangular groove 103b having a long vertical direction in the second grid direction. The shape consists of a through hole 104a of a square electron beam and a rectangular groove 104b having a long horizontal direction in the first grid direction. The third grid has a circular electron beam through hole 105a and a second shape. The rectangular groove 105b having a long vertical direction in the grid direction is formed.

The specific dimensions of the grooves of the first grid, the second grid, and the third grid are described in detail in the diagram.

The through-hole dimension of the electron beam is standardized as the first grid (□ 0.6mm), the second grid (□ 0.6mm), and the third grid (φ1.5mm), and the gap between the first grid and the second grid ( G1-G2) is 0.14 ± 0.05 mm, and the electrode is arranged at a distance of 1.05 ± 0.05 mm between the second and third grids.

The dimensions and spacing of each electrode described above have tolerances that may occur in electrode manufacturing and electron gun manufacturing (indicated by '±').

The present invention configured as described above has a structure designed to minimize the dent of the electron beam when the electron beam is deflected to the periphery of the screen. In the electron beam spot of the periphery of the screen by minimizing, the halo part is eliminated to improve the resolution over the entire screen area. The principle of forming the transverse electron beam according to the present invention is as shown in the electrode arrangement and electron lens formation of FIG. 3 according to the present invention. The focusing action of the electron beam in the horizontal direction is different.

That is, as shown in FIG. 3, when the electrode is thick in the horizontal direction of the first grid, the electron lens L1 has a strong focusing effect, and thus the crossover Ch where the electron beam is collected at one point is the cathode 101. As the electron beam approaches the plane and collects at one point, the electron beam passes through the second and third grids. The focusing effect of the pre-focus lens L2 for focusing the divergent electron beam is also lower in focusing force than in the vertical direction because of the difference in thickness between the horizontal and vertical directions of the second grid 104 and the third grid 105. The electron beam diameter before the lens L3 is incident is larger than the vertical direction. The focusing principle in the horizontal direction is opposite to the horizontal direction because the focusing principle in the vertical direction is always opposite to the vertical direction.

That is, since the focusing in the vertical direction is stronger than in the horizontal direction, the electron beam diameter before the main lens incident becomes small, so that the horizontal electron beam 111 can be obtained.

As shown in the calculation result and the sample test result in FIG. 5, the aspect ratio (H / V) of the electron beam before the main lens L3 is incident is represented by the spot diameters 112 and 113 at the center of the screen and the periphery of the screen. .

That is, as the H / V ratio increases, the spot increases in the center of the screen, and when the H / V ratio decreases, the spot increases around the screen and the resolution of the CRT deteriorates.

Referring to FIG. 5, it can be seen that the spot diameters of the center and the periphery of the screen are the same when the H / V ratio is around 1.7.

In order to make the H / V ratio to 1.7, the H / V ratio can be made at the same electrode dimensions as shown in Table 1 for determining the groove dimensions of each electrode and at the intervals between the electrodes.

That is, it can be seen from the experiment that when the distance G1-G2 between the first grid G1 and the second grid G2 is close, the H / V value increases but the withstand voltage deteriorates. In addition, the interval G2-G3 between the second grid G2 and the third grid G3 has the same effect.

In conclusion, the interval is set in consideration of the H / V ratio and STRAY EMISSION.

As shown in FIG. 2, the lengthened electron beam is deflected in the vertical direction because the size of the electron beam in the vertical direction is smaller than the horizontal direction as in the degree of distortion of the electron beam by the PIN-CUSHION magnetic field 7. The aberration becomes small.

In fact, the pincushion magnetic field 7 becomes strong at the periphery of the screen, so the electron gun according to the present invention shows a slight longitudinal electron beam spot (Fig. 8) at the center of the screen and a halo (peripheral screen) as shown in Fig. 10) It is possible to increase the resolution of the color CRT by obtaining an electron beam without the

The effect of the present invention is that the electron gun for the color cathode ray tube according to the present invention becomes only a core portion having a high density of the electron beam from the center to the periphery of the screen, so that the CRT employing the electron gun according to the present invention has a high resolution to the center as well as the periphery. The effect can be obtained.

Claims (3)

In the in-line color cathode ray tube consisting of the point wood, the first grid, the second grid, the third grid, and the fourth grid sequentially arranged in the screen direction, the electron beam through hole 3a of the first grid is formed. Has a square shape, a rectangular groove having a long vertical direction in the second grid direction is provided, and the second grid has a horizontal direction in the direction of the first grid 3 in the square electron beam through hole 4a. An electron muzzle for a color cathode ray tube, characterized in that it has a long rectangular groove, and the third grid has a circular electron beam passing hole (5a) and a rectangular groove having a long vertical direction in the second grid direction. The groove length of the first grid, the second grid, and the third grid, wherein the groove length of the first grid is 0.6-0.8 (H1), the second grid is 1.6-1.8 ( H2), the third grid is 1.46-1.66 (H3), the longitudinal length of the groove is 1.9-2.1 (V1), and the second grid is 1.7-1.9 (V2), and the third grid is 3.9-4.1 (V3), the depth t of the groove having a groove depth of the first grid of 0.09-0.15, the second grid of 0.1-0.2, the third grid of 0.28-0.38. The electron gun sphere for color cathode ray tube according to claim 2, wherein a distance between the first grid and the second grid is 0.09-0.19 mm, and a distance between the second grid and the third grid is 1.0-1.1 mm.