KR950001495B1 - Double dynymic focusing electron gun for c-crt - Google Patents

Abstract

The device improves the focus characteristics of electron beam, and generates the equivalent magnitude of electron beam spot. The device includes the cathode , the 1st and 2nd grids, the 3rd, 4th, 5th grids which form the uni-potential focus auxilliary electro-static lens, the 5th and 6th grids which form the bi-potential focus auxilliary electro-static lens, the 7th grid which form the main lens. The electron beam plane of the 4th grid (44) forms the R,G,B consecutive electron beam holes, the electron beam input plane of the 5th grid (45) forms the circular-rectangular type electron beam holes, and the electron input plane of the 7th grid (47) forms 3 circular type electron beam holes.

Description

Double Dynamic Focusing Gun for Color Cathode Ray Tubes

1 is a conventional single dynamic focusing electron gun for color cathode ray tubes, wherein a is a perspective view thereof, and b is an electron beam path diagram.

2 is a conventional DOUBLE dynamic focusing electron gun for color cathode ray tubes, wherein a is a perspective view, and b is an electron beam path diagram thereof.

3 is a double dynamic focusing electron gun for a color cathode ray tube according to the present invention, where a is a perspective view thereof, and b is an electron beam path diagram thereof.

4 is a second embodiment of the present invention, in which a is a perspective view and b is an electron beam path diagram.

5 is a table comparing the results of the electron gun of the present invention and the conventional electron gun.

* Explanation of symbols for the main parts of the drawings

10, 20, 30, 40: cathode 11, 21, 31, 41: first grid

12, 22, 32, 42: Second grid 13, 23, 33, 43: Third grid

14, 24, 32, 44: 4th grid 15, 25, 35, 45: 5th grid

16, 26, 36, 46: 6th grid 27, 37, 47: 7th grid

A1, B1, C1, D1: first quadrupole lens B2, C2, D2: second quadrupole lens

A3, B3, C3, D3: Main lens A4, B4, C4, D4: Deflection yoke lens

Vf: Focus Voltage Vd: Dynamic Focus Voltage

Va: anode wood voltage

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun for color cathode ray tubes, and more specifically, to FST (FULL SQUARE TUBE), ultra-large, optical deflection angle, high definition, and deflection yoke of a CRT. Compensates for the deterioration of the focus characteristics of the electron beams due to the convergence of the SELF, and reduces the lateralization of the electron beams generated at the periphery of the screen and improves the focus characteristics to obtain an electron beam spot of uniform size on the entire screen. A double dynamic focusing gun for color cathode ray tubes.

The resolution of the color cathode ray tube depends on the size of the electron beam landing on the fluorescent surface. Therefore, in order to obtain a high resolution image quality, it is important that the size of the electron beam landing on the fluorescent surface is as small as possible, without distortion, and without HALO. However, in the conventional electron gun, the deflection yoke is provided because the R, G, and B guns are arranged inline, and a deflection yoke is provided to form a pincushion type horizontal deflection magnetic field and a barrel type vertical deflection magnetic field. The non-uniform magnetic field of the arc causes astigmatism of the electron beam emitted from the electron gun and landing.

That is, since the deflection magnetic field is not formed when the electron beam emitted from the electron gun is landed at the center portion of the fluorescent film, astigmatism of the electron beam does not occur, thereby obtaining a circular electron beam spot without phase spreading. However, when the electron beam is deflected to the periphery of the fluorescent film, it is diverged horizontally by the deflection magnetic field and is over-focused in the vertical direction, so that the electron beam formed on the screen has a low luminance in the vertical direction with a high brightness CORE portion in the horizontal direction. It has an upper spreading portion, and the resolution of the screen is lowered.

Figure 1 shows an example of a conventional single dynamic focusing electron gun for color cathode ray tubes to solve this problem.

This includes the cathode 10, the first and second grids 11 and 12 forming the triode, and the third and fourth grids 13 and 14 forming the auxiliary lens, and the fourth grid 14 and The fifth grid 15 is provided to be adjacent to form the main lens A3. Three elongated electron beam through holes are formed in the electron beam exit plane of the third grid 13. Three transverse electron beam passing holes are formed in the electron beam incident plane of the id 14.

In addition, a predetermined focus voltage Vf is applied to the third grid 13, and the focus voltage VF is applied to the fourth grid 14 as a base voltage, and synchronized with a deflection yoke deflection signal. The dynamic focus voltage Vd, which is modulated, is applied, and an anode voltage Va higher than the focus voltage Vf is applied to the fifth glide 15.

In the conventional single dynamic focusing electron gun for color cathode ray tubes configured as described above, when the electron beam is not deflected, that is, when the electron beam emitted from the electron gun is scanned to the center of the fluorescent film, the focus voltage Vf and the fourth grid 14 Since a dynamic focus voltage Vd of the same low level is applied, a quadrupole lens is not formed between the third grid 13 and the fourth grid 14. Therefore, the electron beam is landing in the best state in the center of the fluorescent film with its circular cross section.

In addition, when the electron beam emitted from the cathode 10 is deflected to the periphery of the fluorescent film, a dynamic focus voltage Vd modulated in synchronization with a deflection signal is applied to the fourth grid 14. A quadrupole lens is formed between 13) and the fourth grid 14. That is, since the electron beam exit hole of the third grid 13 has an elongated electron beam through hole, and the electron beam incident plane of the fourth grid 14 has a transverse electron beam through hole formed therein. A quadrupole lens having diverging force and a focusing force in a horizontal direction is formed.

Accordingly, the electron beam emitted from the cathode 10 is lengthened while passing through the quadrupole lens, and the distortion of the electron beam generated by the non-uniform magnetic field during deflection by the deflection yoke is corrected, thereby causing the peripheral portion of the fluorescent film to be corrected. Landing.

However, in the conventional single dynamic focusing electron gun for color cathode ray tubes as described above, when the electron beam is scanned to the periphery of the fluorescent film, the vertical electron beam is emitted by the first quadrupole lens A1 by the main lens A3. The main lens is weakened by applying dynamic focus voltage when the electron beam is scanned around the fluorescent film. After passing through the outer side, the deflection yoke focusing lens A4 receives a strong focusing action, and thus, the upper spreading component disappears at the periphery of the fluorescent film, but the vertical size of the electron beam spot is smaller than the central portion of the fluorescent film due to excessive focusing. You lose.

The horizontal electron beam is focused by the first quadrupole lens A1 and passes through the inner side of the main lens A3 where the strength of the lens is weakened, thereby receiving a strong diverging action by the deflection yoke diverging lens A4. The core component of is formed without any difference from when no dynamic focus voltage is applied.

In the periphery of the fluorescent film of the single dynamic focusing electron gun for the color cathode ray tube, the conventional double dynamic focusing electron gun for the color cathode ray tube for improving the excessive compression in the vertical direction of the electron beam spot and the horizontal core phenomenon in the horizontal direction is shown in FIG. Is shown.

This includes the cathode 20, the first grid 21, and the second grid 22, which form the triode, and the third, fourth, and fifth, which form the UNI-POTENTIAL FOCUS auxiliary electrostatic lens B1. A sixth grid 26 constituting a grid 23, 24, 25, the fifth grid 25, and a bi-potential focus auxiliary electrostatic lens B2; The seventh grid 27 is provided to be adjacent to the six grids 26 to form the main lens B3.

Three vertical slot (SLOT) type electron beam through holes are formed in the electron beam passing plane of the fourth grid 24, and three horizontal slots in the electron beam incident plane of the fifth grid 25 are formed. The electron beam through hole has three longitudinal slotted electron beam through holes formed in the exit plane thereof, and three horizontally slotted electron beam through holes are formed in the electron beam incidence plane of the sixth grid 26. .

In addition, a predetermined focus voltage Vf is applied to the third grid 23 and the fifth grid 25, and the focus is applied to the fourth grid 24 and the sixth grid 26. A dynamic focus voltage Vd modulated in synchronization with the deflection signal of the deflection yoke is applied to the voltage Vf as a base voltage, and an anode voltage higher than the focus voltage Vf is applied to the seventh grid 27. (Va) is applied.

The conventional double dynamic focusing electron gun for the color cathode ray tube shown in FIG. 2 configured as described above is uniformly focused by the third, fourth, and fifth grids 23, 24, and 25 as a predetermined potential is applied to each of the electrodes. A lens B1 is formed, and the bipotential focus lens B2 is formed by the fifth and sixth grids 25 and 26, and the main body is formed by the sixth and seventh grids 26 and 27. Lens B3 is formed. The electron beam emitted from the cathode 20 is connected and accelerated by an electrostatic lens formed between each electrode to be scanned into the fluorescent film formed on the inner surface of the panel. At this time, the scanning state of the electron beam is directed to the center portion and the peripheral portion of the fluorescent film. The description is as follows.

First, when the electron beam emitted from the cathode 20 is scanned to the center portion of the fluorescent film, the dynamic focus voltage Vd of the equipotential equal to the focus voltage Vf is applied to the fourth and sixth grids 24 and 26. Since it is applied, the quadrupole lens is not formed between the third, fourth, fifth, and sixth grids 23, 24, 25, and 26. Therefore, the electron beam is landing in the best state in the center of the fluorescent film with its circular cross section.

When the electron beam is deflected to the periphery of the fluorescent film, the dynamic focus modulated by the deflection yoke deflection signal to the fourth and sixth grids 24 and 26 and modulated by using the focus voltage Vf as a base voltage. Since the voltage Vd is applied, three longitudinal horizontal slot electron beam passing holes are formed between the third, fourth, and fifth grids 23, 24, and 25. The unpotential first quadrupole lens B1 is formed by three horizontally slotted electron beam passing holes formed in the electron beam incident plane of the fifth grid 25. In addition, between the fifth and sixth grids 25 and 26, three longitudinal slot electron beam through-holes formed in the electron beam exit plane of the fifth grid 25 and the sixth grid 26 are formed. A bipotential second quadrupole lens B2 is formed by three horizontally-sized horizontal slot electron beam through holes formed in the electron beam incident plane.

Accordingly, the electron beam emitted from the cathode 20 diverges in the vertical direction and in the horizontal direction while passing through the unpotential first quadrupole lens (hereinafter referred to as the first quadrupole lens) as shown in FIG. While passing through the bi-potential second quadrupole lens (hereinafter referred to as the second quadrupole lens), it was diverged in the vertical direction and focused in the horizontal direction to lengthen the focal length in the vertical direction to alleviate excessive compression of the electron beam spot.

That is, when the electron beam is deflected to the periphery of the fluorescent film, in the vertical direction, the light is focused in the first quadrupole lens B1 and incident on the second quadrupole lens B2 with a small vertical mirror, and then diverges. After being weakly sustained past, the deflected yoke focusing legs B4 are focused again to increase the focal length, thereby improving the vertical length of the electron beam spot.

However, the horizontal electron beam diverges from the first quadrupole lens B1 and is incident on the second quadrupole lens B2 with a large horizontal mirror, and is then focused, passed through the outside of the main lens B3, and deflected yoke divergence. Although emitted from the lens B4, the focal length does not decrease significantly compared to the single dynamic focusing electron gun, so that the horizontal lateralization of the electron beam spot is not improved.

In order to solve this problem, an object of the present invention is to improve the horizontalization of the electron beam spot in the horizontal direction when the electron beam is deflected to the periphery of the fluorescent film, so that the electron beam spot of uniform size can be obtained at full screen. It is to provide a focusing electron gun.

In order to achieve the above object, the present invention provides a cathode, a first grid and a second grid, and a third, fourth, and fifth grid forming a unipotential focus assist electrostatic lens. With fifth and sixth grids forming a lens. In the double dynamic electron gun for color cathode ray tube provided with a seventh grid formed adjacent to the sixth grid to form a main lens, one R, G, B continuous in the electron beam passing plane of the fourth grid The elongated pea shell of the shape of the electron beam through-holes (three isolated circles are connected to each other in a row) is formed, and three circular electron beam through-holes are emitted from the electron beam incidence plane of the fifth grid. In the plane are formed three elongated, medium-square rectangles: an arc-shaped cutout in the middle of the long side edge, with an intermediate opening extending in the middle thereof that extends beyond the length of the short side. In the electron beam incidence plane of the sixth grid, R, G and B consecutive one row-shaped pea shell electron beam through holes are formed, and in the outgoing plane three circular electron beam through holes are formed. Three circular electron beam through holes are formed in the electron beam incident plane of the seventh grid, and a predetermined focus voltage is applied to the third and fifth grids, and the focus voltage is applied to the fourth and sixth grids. It is characterized in that the base voltage is applied and a dynamic focus voltage modulated in synchronization with the deflection signal of the deflection oak is applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Example 1

3 shows a perspective view and an electron beam path diagram of a double dynamic focusing electron gun for a color cathode ray tube according to the present invention, which comprises a cathode 30, a first grid 31, and a second grid 32 that form a triode portion. ), The third, fourth and fifth grids 33 and 34 and 35 forming the unpotential focus lens C1 and the fifth and sixth grids 35 forming the bipotential focus lens C2. And a seventh grid 37 provided adjacent to the sixth grid 36 to form the main lens C3.

In the electron beam passing plane of the fourth grid 34, one horizontally-penetrated pea-shell electron beam through-hole is formed in a row of R, G, and B, and three electron beam through-holes of the fifth grid 35 are formed. Three circular electron beam through-holes, three elongated heavy-duty electron-beam through-holes are formed in the exit plane, and one transverse-continuous R, G, and B-continuous in the electron beam incident plane of the sixth grid 36 Pea shell-type electron beam through holes, three circular electron beam through holes are formed in the emission plane, and three circular electron beam through holes are formed in the electron beam incidence plane of the seventh grid 37.

In addition, a predetermined focus voltage Vf is applied to the third and fifth grids 33 and 35, and the focus voltage Vf is applied to the fourth and sixth grids 34 and 36. A dynamic focus voltage Vd modulated in synchronization with the deflection yoke's deflection signal is applied.

The operation of the dynamic focusing electron gun for color cathode ray tube according to the present invention configured as described above is as follows.

As shown in FIG. 3, when a predetermined voltage is applied to each electrode, the electron beam emitted from the cathode 30 is scanned into a fluorescent film to form one pixel, and the pixels are gathered to form a screen. In this case, the scanning state of the electron beam is divided into the center and the periphery of the fluorescent film and described as follows.

First, when the electron beam is scanned to the center of the fluorescent film, since it is not deflected by the deflection yoke, the dynamic focus voltage Vd of equipotential equal to the focus voltage Vf is applied to the fourth and sixth grids 34 and 36. Since this is applied, the quadrupole lens is not formed between the third, fourth, fifth, and sixth grids 33, 34, 35, and 36. Therefore, the electron beam is landing in the best state in the center of the fluorescent film with its circular cross section.

When the electron beam is scanned to the periphery of the fluorescent film, the dynamic focus modulated by the fourth and sixth grids 34 and 36 in synchronization with the deflection signal of the deflection yoke and modulated by using the focus voltage Vf as a base voltage. Since a voltage Vd is applied, R, G, and B consecutively formed horizontally formed in the fourth grid plane 34 between the third, fourth, fifth grid 33, 34, 35. The unipotential type first quadrupole lens C1 is formed by the pea shell electron beam through hole of and the three circular electron beam through holes formed in the electron beam incident plane of the fifth grid 35. In addition, between the fifth and sixth grids 35 and 36, three long-shaped medium-square electron beam passing holes formed in the electron beam exit plane of the fifth grid 35 and the sixth grid 36 are formed. The bipotential-type second quadrupole lens C2 is formed by R, G, and B continuous pea skin electron beam passing holes formed in the electron beam incident plane.

Therefore, the electron beam emitted from the cathode 30 is diverged in the vertical direction and focused in the horizontal direction while passing through the unpotential first quadrupole lens (hereinafter referred to as the first quadrupole lens) as shown in FIG. While passing through the bi-potential second quadrupole lens (hereinafter referred to as the second quadrupole lens), the beam diverges in the vertical direction and focuses in the horizontal direction. Therefore, the astigmatism correction effect and the focus correction effect of the electron beam due to the geometric curvature of the fluorescent film and the nonuniform magnetic field of the deflection yoke can be improved. In addition, since the dynamic focus voltage Vd having the focus voltage Vf as the base voltage is applied to the sixth grid 36, the sixth grid 36 and the sixth grid 36 are applied to the sixth grid 36. As a result, the potential difference between the seven grids 37 becomes small, and as a result, the intensity of the main lens C3 is weakened, and thus the focal length of the electron beam becomes long, so that the optimum focus can be obtained at the periphery of the fluorescent film.

In more detail, when the electron beam is deflected to the periphery of the fluorescent film, it is emitted from the first quadrupole lens C1 in the vertical direction and is incident on the second quadrupole lens C2 with a large vertical mirror, and then the second quadrupole lens ( C2) diverges again to a large vertical mirror to increase the angle of incidence to the main lens C3, thereby excluding the strong focusing action at the outermost side of the main lens C3, which is weak in intensity, thereby lengthening the focal length in the vertical direction. In addition, the electron beam in the horizontal direction is focused by the first quadrupole lens C1 and incident on the second quadrupole lens C2 with a small horizontal mirror, and then focused again by the second quadrupole lens C2 with a small horizontal mirror, thereby increasing its intensity. After entering the deflection yoke diverging lens C4 at a small angle of incidence past the weak main lens C3, the beam is diverged at a small angle to shorten the focal length.

As a result, the vertical distance of the electron beam spot can be increased by increasing the focal length in the vertical direction, and the lateralization of the electron beam spot can be reduced by shortening the focus distance in the horizontal direction.

Example 2

4 is a perspective view and electron beam path diagram of the double dynamic focusing electron gun for the color cathode ray tube according to the present embodiment, which are the cathode 40, the first grid 41, and the second grid, which form a triode; (42), third, fourth, and fifth grids 43, 44, and 45 forming the unpotential focus lens D1, and the fifth and sixth grids forming the bipotential focus lens D2. 45 and 46, and a seventh grid 47 provided adjacent to the sixth grid 46 to form a main lens D3.

In the electron beam passing plane of the fourth grid 44, one horizontally-penetrated pea-shell electron beam through-hole of R, G, and B is continuous, and three electron beam incidence planes of the fifth grid 45 are formed. An elongated medium-square electron beam pass-through hole has three long elongated mid-angle electron beam pass-holes formed at its exit plane, and one transversely continuous R, G, and B in the electron beam incident plane of the sixth grid 46. In the long pea shell electron beam through hole, three circular electron beam through holes are formed in the emission plane, and three circular electron beam through holes are formed in the electron beam incidence plane of the seventh grid 47.

In addition, a predetermined focus voltage Vf is applied to the third and fifth grids 43 and 45, and the focus voltage Vf is applied to the fourth and sixth grids 44 and 46. The dynamic focus voltage Vd modulated in synchronization with the deflection yoke's deflection signal is applied. The result is the same as that of the first embodiment.

As described above, the double dynamic focusing electron gun for color cathode ray tube according to the present invention has the same polarity as the horizontal and vertical intensities of the first and second quadrupole lenses C1 and D1 (C2 and D2) when the electron beam is deflected toward the periphery of the fluorescent film. By changing the focusing and divergence intensity in the direction of astigmatism, the astigmatism correction effect and the focusing characteristic are improved, thereby preventing the electron beam from being lateralized and obtaining an electron beam spot of uniform size on the full screen. In addition, since the quadrupole electrodes are formed in a circular shape, the alignment of the quadrupole electrodes can be improved by using a central jig, which is a circular mandrel, when assembling the electron gun.

5 shows a conventional electron gun at the side of the fluorescent film (SIDE: 3 o'clock and 9 o'clock) of the fluorescent film and the corner (CORNER: the outermost point of the diagonal end of the fluorescent film) for a certain amount of Ik (cathode current). And the change in the size of the horizontal beam diameter of the electron gun according to the present invention was compared and shown using the following percentage equation.

Claims (2)

The cathode, the first grid and the second grid forming the tripolar portion, the third, fourth, and fifth grids forming the unipotential focus auxiliary electrostatic lens, and the fifth, sixth grid constituting the bipotential focus auxiliary electrostatic lens; In the double dynamic electron gun for color cathode ray tube provided with a seventh grid is formed adjacent to the sixth grid to form a main lens, the electron beam passing plane of the fourth grid (34) is R, G, B burned one row-shaped pea shell electron beam through-hole is formed, three circular electron beam through-holes are formed in the electron beam incidence plane of the fifth grid 35, and three elongated heavy circles (middle) Iii) A square electron beam through hole is formed, and in the electron beam incidence plane of the sixth grid 36, one horizontal, pea-pea type electron beam through hole successively R, G, and B is formed, and three circular circles are provided in the emission plane. An electron beam through hole is formed, and three circular electron beam through holes are formed in the electron beam incidence plane of the seventh grid 37, and a predetermined focus voltage is formed in the third and fifth grids 33 and 35. (Vf) is applied, and the fourth and sixth grids 34 and 36 have a dynamic focus voltage Vd modulated in synchronization with the deflection signal of the deflection yoke and the focus voltage Vf as a base voltage. A double dynamic focusing electron gun for color cathode ray tubes, characterized in that it is applied. The electron beam passing hole of the fourth grid 44 is formed with one horizontally-penetrated pea shell electron beam through-hole formed in succession of R, G, and B, and incident of the electron beam of the fifth grid 45. In the plane, three elongated, medium-square electron beam through holes are formed, and in the emission plane, three elongated, medium-square electron beam through holes are formed, and in the electron beam incident plane of the sixth grid 46, R, G, and B consecutive One horizontal pea-peam-type electron beam through-hole has three circular electron beam through-holes formed at its exit plane, and three circular electron beam through-holes are formed at the electron beam incident plane of the seventh grid 47. A double dynamic focusing gun for color cathode ray tubes.