KR20030029658A - Electron gun for color cathode-ray tube - Google Patents

Abstract

PURPOSE: An electron gun for a color cathode ray tube is provided to achieve improved resolution by changing the path of electron beams at a predetermined angle and preventing distortion of the screen. CONSTITUTION: An electron gun comprises three cathodes(21) serving as an electron beam emitting source; a control electrode(22) for controlling electron beams emitted from each of three cathodes; a screen electrode(24) arranged in the vicinity of the control electrode, and which has a first lead-in portion formed at the exit side of a central electron beam passing hole(25a) and a second lead-in portion formed at side electron beam passing holes(25b), wherein the screen electrode changes the path of electron beams passing through the side electron beam passing holes; focusing electrodes(29) having electron beam passing holes(30), and which form a plurality of auxiliary lenses; and a final accelerating electrode arranged in the vicinity of the focusing electrodes, and which forms a main lens.

Description

Electron gun for color cathode-ray tube

The present invention relates to an electron gun for a color cathode ray tube, and more particularly, to an electron gun for a color cathode ray tube having an improved structure of a screen electrode constituting a triode of the electron gun.

In general, a color cathode ray tube is fused with a funnel in which a neck part is integrally formed on a panel, and the neck part emits three electron beams of red (R), green (G), and blue (B). An electron gun is enclosed, and a fluorescent film that emits light as the electron beam collides is applied to the inner surface of the panel. A deflection yoke is fixed across the panel along the outer circumference of the neck to deflect the electron beam emitted from the electron gun.

Fig. 1 is a side view showing the configuration of an electron gun in such a color cathode ray tube, and includes three cathodes 1 for mounting a heater (not shown) to emit hot electrons in accordance with an input electrical signal. The control electrode (2) for controlling the electron beam emitted in one direction of the (1), the screen electrode (3), which is an acceleration electrode to pull and accelerate the electron beam gathered on the surface of the cathode (1), and to accelerate and narrow the electron beam A plurality of focusing electrodes 4 and final acceleration electrodes 5 which are provided adjacent to the focusing electrodes 4 to form a main lens are sequentially arranged and fixed by the bead glass 6.

Self-convergence inline color cathode ray tubes typically have a deflection yoke that forms a non-uniform magnetic field to deflect the electron beam emitted from the electron gun. That is, the electron beams emitted from the electron gun are focused on the electron beam by a main lens installed in the electron gun, and convergence is performed throughout the screen by a non-uniform magnetic field consisting of a pincushion type horizontal deflection magnetic field and a barrel type vertical deflection magnetic field. do. When passing through the non-uniform magnetic field, the electron beam located in the periphery of the three electron beams arranged in the line is more distorted than the electron beam in the center.

In order to prevent such a phenomenon, a method of designing an asymmetric triode has been proposed.

Among them, the electron gun disclosed in U.S. Patent No. 4,523,123 has three through holes through which electron beams pass through the screen electrode in a row in a transverse direction, and each of the exit holes has a horizontal slot and an inner surface with a slot formed in a flat portion. It is. The slots formed in the through holes in the center of the through holes are formed symmetrically with respect to the center axis of the through holes, and the slots formed in the surrounding through holes are formed asymmetrically with respect to the center axis of the through holes. The inner width of the ball is greater than the outer width on the central axis of the ball, and the inner depth is the same as the outer depth. Therefore, in the peripheral through holes, the equipotential lines are asymmetrically arranged so that the electron beam passing through the peripheral through holes is bent at an angle from the center axis of the through hole to a pre-focus lens. Proceed to

As another example, the electron gun disclosed in U.S. Patent No. 5,198,719, like the above-described example, has a slot having a horizontal portion on each exit side of the three through holes and a planar portion on the inner surface thereof, and a center through hole among these through holes. Slots formed in the symmetrical with respect to the central axis of the through hole, while slots formed in each of the peripheral through holes are formed asymmetrically with respect to the central axis of the through hole. On the other hand, the slots formed in the through holes around the inner width is greater than the outer width on the border of the central axis of the through hole, the inner depth is greater than the outer depth. Therefore, in the peripheral through holes, the equipotential lines are asymmetrically arranged so that the electron beam passing through the peripheral through holes is bent at an angle from the center axis of the through hole to a pre-focus lens. Proceed to

The present invention is to solve the above problems, of the three through-holes formed in the screen electrode, the first inlet to form a symmetrical equipotential line is formed on the exit side of the through-hole in the center of the through-holes, For the color cathode ray tube which can increase the resolution by preventing the distortion phenomenon around the screen by changing the path of the electron beams passing through the periphery of the through holes, respectively, by forming a second inlet to form asymmetrical equipotential lines on each exit side The purpose is to provide an electron gun.

BRIEF DESCRIPTION OF THE DRAWINGS The side view which shows the structure of an electron gun in the normal color cathode ray tube.

Figure 2a is a perspective view showing a triode according to an embodiment of the present invention.

FIG. 2B is a perspective view of the screen electrode according to the first embodiment of FIG. 2A; FIG.

FIG. 2C is a cross-sectional view illustrating the path of an electron beam passing through the screen electrode and the focusing electrode of FIG. 2A; FIG.

3A is a perspective view illustrating a screen electrode according to a second embodiment of the present invention.

3B is a cross-sectional view illustrating the path of an electron beam passing through the screen electrode and the focusing electrode of FIG. 3A;

4A is a perspective view illustrating a screen electrode according to a third embodiment of the present invention.

4B is a cross-sectional view illustrating the path of an electron beam passing through the screen electrode and the focusing electrode of FIG. 4A;

5A is a perspective view illustrating a screen electrode according to a fourth embodiment of the present invention.

FIG. 5B is a cross-sectional view illustrating the path of an electron beam passing through the screen electrode and the focusing electrode of FIG. 5A; FIG.

Figure 6a is a perspective view showing a screen electrode according to a fifth embodiment of the present invention.

6B is a cross-sectional view illustrating the path of an electron beam passing through the screen electrode and the focusing electrode of FIG. 6A;

<Brief description of the major symbols in the drawings>

21. Cathode 22. Control electrode

24, 61. Screen electrode 25. Second electron beam passing hole

26 .. Passing study 27. First entry

28. 2nd inlet 28a, 65b.

28b.Steps 28c, 65a.

29. Focusing electrode

Electron gun for color cathode ray tube according to the present invention for achieving the above object,

Three cathodes which are the emission sources of the electron beam;

A control electrode for controlling electron beams emitted from the cathodes;

It is installed adjacent to the control electrode, the first inlet symmetrical with respect to the central axis of the through hole is formed on the exit side of the through hole of the center of the electron beam passing through each electron beam passing through the control electrode, On the exit side of the through hole of the horizontal width is smaller than the horizontal width of the horizontal type, the inner surface is formed with a second inlet portion having an inclined portion inclined along the transverse direction, the path of the electron beam passing through the surrounding through holes A screen electrode for changing;

Focusing electrodes each having electron beam passing holes having a predetermined shape formed from the screen electrodes to form a plurality of auxiliary lenses; And

And a final acceleration electrode installed adjacent to the focusing electrode to form a main lens.

In addition, the electron gun for a color cathode ray tube according to the present invention,

Three cathodes which are the emission sources of the electron beam;

A control electrode for controlling electron beams emitted from the cathodes;

It is installed adjacent to the control electrode, among the through holes formed to pass each electron beam passing through the control electrode is formed on the exit side of the through hole in the center symmetrical with respect to the central axis of the through hole is formed, On the exit side of the through-holes of the periphery, the horizontal width is smaller than the horizontal width, and based on each central axis of the through-holes, a flat portion is formed on one side, the other side inclined downward in the horizontal direction from the vertical end of the exit side A second lead portion having an inclined portion, wherein the screen electrode changes the path of the electron beam passing through the peripheral through holes;

Focusing electrodes each having electron beam passing holes having a predetermined shape formed from the screen electrodes to form a plurality of auxiliary lenses; And

And a final acceleration electrode installed adjacent to the focusing electrode to form a main lens.

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

In the color cathode ray tube, the electron gun is installed in the neck portion of the cathode ray tube to emit an electron beam to excite the fluorescent film, the cathode and the control electrode and the screen electrode constituting the triode, a plurality of focusing electrodes to form an auxiliary lens and And a final acceleration electrode forming the main lens.

In the electron gun, an embodiment of the tripolar portion forming the emission of the electron beam and the water point is shown in Figure 2a. In FIG. 2B, the screen electrode according to the first embodiment is illustrated in FIG. 2A, and FIG. 2C is a cross-sectional view illustrating a path of an electron beam passing through the screen electrode and the focusing electrode.

As shown, the three cathodes 21 constituting the triode include an electron-emitting part 21a impregnated or coated with an electron-emitting material, and a heater 21b for heating the electron-emitting part 21a. .

The first electron beam through hole 23 is formed at a position corresponding to each of the cathodes 21 in the control electrode 22 disposed adjacent to the cathode 21. The control electrode 22 controls the electron beams emitted from the cathodes 21, respectively. The first electron beam passing hole 23 is formed in a circular shape, but is not limited thereto and may be modified in various forms for changing the cross-section of the electron beam.

In addition, a screen electrode 24 is installed adjacent to the control electrode 22. The screen electrode 24 is formed in a plate shape, and each of the cathode 21 and the first electron beam passing holes 23 is formed. The second electron beam through holes 25 are formed coaxially, respectively.

In addition, a focusing electrode 29 is provided to correspond to the screen electrode 24, and a pre-focus lens is formed between the screen electrode 24 and the focusing electrode 29. A third electron beam through hole 30 is formed coaxially with the second electron beam through hole 25 in the focusing electrode 29.

Through holes 26 are formed in the second electron beam through holes 25 of the screen electrode 24, and the first inlet part 27 is formed on the exit side of the through hole 25a in the center. The second lead portion 28 is formed in the through holes 25b.

The outer shape of the first and second inlet portions 27 and 28 is a horizontal shape in which the vertical width W1 is smaller than the horizontal width W2. The through hole 26 is shown in a circular shape, but is not limited thereto. In addition, the vertical width (W1) of the first and second inlet portion 27, 28 is preferably formed to be greater than or equal to the diameter (D) of the through hole 26, but is not limited thereto.

The first lead portion 27 is formed to be drawn to a predetermined depth, the bottom surface is a flat portion (27a). The first inlet part 27 is formed symmetrically with respect to the central axis of the through hole 26.

Incidentally, the second inlet portion 28 has an inclined portion 28a formed on its inner surface in the transverse direction. The inclined portion 28a is inclined from the vertical tip of the exit side to the vertical end opposite thereto.

The vertical length L1 from the emission side surface to the flat portion 27a in the first inlet portion 27 is vertical from the emission side surface in the second inlet portion 28 to the end of the inclined portion 28a. Although shown smaller than the length (L2), it is not limited thereto.

The inclined portion 28a is inclined downward toward the center of the screen electrode 24, or as in the screen electrode 24 according to the second embodiment shown in FIGS. 3A and 3B, both vertical sides of the screen electrode 24 are vertical. Can be inclined downward.

The second lead portion 28 is asymmetrical with respect to the central axis of the through hole 26, such that asymmetric equipotential lines are formed in the surrounding through holes 25b. A different pre-focus lens can be obtained depending on the direction in which the inclined portion 28a is inclined. When the inclined portion 28a is inclined downward toward the center of the screen electrode 24, the through hole 25b around the periphery is formed. Electron beams incident through the pre-focus lenses through the light beams are deflected inwardly at a predetermined angle. That is, the electron beam that has passed through the peripheral passage holes 25b is focused. On the other hand, when the inclined portion 28a is inclined downward to the vertical both sides of the screen electrode 24, the electron beam passing through the peripheral through holes 25b and incident to the pre-focus lens is deflected outward at a predetermined angle. That is, the electron beam passing through the peripheral passage holes 25b is diverged.

In the second lead portion 28, as in the screen electrode 24 according to the third embodiment shown in FIGS. 4A and 4B, a step portion 28b is formed inward from the vertical tip of the emission side. An inclined portion 28a that is inclined from the end of the step portion 28b to the vertical end of the emission side surface opposite thereto may be formed.

In addition, as in the screen electrode 24 according to the fourth embodiment shown in FIGS. 5A and 5B, a flat portion 28c is respectively defined at the front end of the step portion 28b and the vertical end of the emission side opposite thereto. It can be formed in width.

The step portion 28b and the planar portion 28c formed on the second lead portion 28 may be formed on the screen electrode 24 shown in FIG. 3A as well as the screen electrode 24 shown in FIG. 2A. .

The second inlet portions 28 formed in the peripheral through holes 25b are preferably symmetrical with respect to the center through hole 25a.

As described above, the inclination value of the inclined portion 28a is θ, the vertical length from the exit side to the end of the inclined portion 28a is L2, the vertical length of the stepped portion 28b is L3, and the stepped portion is When the horizontal lengths of the flat portion 28c formed at the front end of the 28b and the vertical end of the exit side opposite to each other are L4 and L5, the θ, L2, L3 is used when designing the second lead portion 28. , L4, and L5 and the distribution of the asymmetric equipotential lines according to the values of the vertical width W1 and the horizontal width W2 of the second lead portion 28 can be adjusted so that the screen electrode 24 and the focusing electrode can be adjusted. It is possible to deform the pre-focus lens formed between the 29 to a predetermined shape.

6A and 6B show a screen electrode according to the fifth embodiment.

6A and 6B, in the screen electrode 61, the second inlet 65 formed in the peripheral through holes 62b is based on each central axis of the through holes 63, and is flat on one side thereof. The part 65a is formed, and the inclination part 65b is formed in the other side.

The planar portion 65a is formed on a bottom surface drawn by the vertical length L6 from the emission side surface, and the inclined portion 65b is formed to be inclined downward at a predetermined angle in the transverse direction from the vertical tip of the emission side surface.

The vertical length L6 from the exit side to the flat portion 65a and the vertical length L7 from the exit side to the end of the inclined portion 65b may be the same as in the drawing. However, it is not limited to this. In addition, although L6 and L7 are shown in figure like the vertical length L1 from the emission side surface in the 1st lead-in part 64 to the flat part 64a, it is not limited to this. In addition, the outer shape of the second lead portion 65 formed in each of the peripheral through holes 62b is horizontal.

On the other hand, the second lead portion 65 may be formed with a flat portion (65a) on the inside, the inclined portion (65b) on the outside with respect to the central axis of the through hole (63). In this case, the electron beam passing through the peripheral through holes 62b is deflected at a predetermined angle inward to proceed to the focusing electrode 29. That is, the electron beam passing through the surrounding through holes 62b is focused.

The present invention is not limited thereto, and the inclined portion may be formed inwardly and the planar portion may be formed outward from the center axis of the through hole. In this case, the electron beam passing through the surrounding through holes may be deflected outward at a predetermined angle. That is, the electron beam passing through the peripheral through holes 62b is diverged.

The second lead portions 65 formed in the peripheral through holes 62b may be symmetrical with respect to the center through hole 62a.

In the electron gun, other focusing electrodes other than the focusing electrode 29 may be provided. In these focusing electrodes, electron beam through holes forming quadrupole lenses may be formed. The final acceleration electrode may be installed adjacent to the focusing electrode positioned at the outermost part of the focusing electrodes, and a main lens is formed between the final acceleration electrode and the focusing electrode.

In the electron gun configured as described above, electrons are emitted from the electron emission unit 21a by the heater 21b of each cathode 21. The electrons emitted as described above pass through a cathode lens formed between the control electrode 22 and the screen electrodes 24 and 61, and then, after forming an object beam of the electron beam, the control electrode 22 and the screen electrode 24. It passes through a beam-forming lens formed between 61.

The electron beam formed through the beam-forming lens is incident on the pre-focus lens formed by the screen electrodes 24 and 61 and the focusing electrode 29.

Meanwhile, among the second electron beam through holes 25 and 62 formed in the screen electrodes 24 and 61, asymmetrical second inlets 28 and 65 are formed in the peripheral through holes 25b and 62b. Since is formed, the electron beam passing through the peripheral through holes 26b and 62b is deflected and travels through the pre-focus lens. That is, the screen electrodes according to the first, third, fourth, and fifth embodiments are focused and progressed, and the screen electrodes according to the second embodiment are diverged and progress.

The electron beam that is focused or diverged as described above passes through the third electron beam through hole 30 of the focusing electrode 29, and an auxiliary lens formed by the focusing electrode 29, other focusing electrodes adjacent thereto, and the final accelerometer lens. Incident and focused on the light and the main lens sequentially.

As described above, the pre-focus lens between the screen electrodes 24 and 61 and the focusing electrode 29 is changed by changing the structure of the second lead portion 28 when designing the screen electrodes 24 and 61. It can be transformed. Therefore, the path of the electron beam passing through the pre-focus lens can be changed at a predetermined angle, thereby preventing distortion around the screen and improving the resolution.

As described above, the electron gun for the color cathode ray tube according to the present invention, among the three through holes formed in the screen electrode, in each of the exit side of the through holes in the periphery, by forming a second inlet formed with a slope on the inner surface, By allowing asymmetric equipotential lines to be formed, the path of the electron beams passing through the pre-focus lens formed between the screen electrode and the focusing electrode can be changed. Therefore, by changing the path of the electron beams to a predetermined angle, it is possible to increase the resolution by preventing the distortion around the screen.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (13)

Three cathodes which are the emission sources of the electron beam; A control electrode for controlling electron beams emitted from the cathodes; It is installed adjacent to the control electrode, the first inlet symmetrical with respect to the central axis of the through hole is formed on the exit side of the through hole of the center of the electron beam passing through each electron beam passing through the control electrode, On the exit side of the through hole of the horizontal width is smaller than the horizontal width of the horizontal type, the inner surface is formed with a second inlet portion having an inclined portion inclined along the transverse direction, the path of the electron beam passing through the surrounding through holes A screen electrode for changing; Focusing electrodes each having electron beam passing holes having a predetermined shape formed from the screen electrodes to form a plurality of auxiliary lenses; And And a final acceleration electrode disposed adjacent to the focusing electrode to form a main lens. The method of claim 1, Electron gun for the color cathode ray tube, characterized in that the second inlet portion formed in the peripheral through holes are symmetrical with respect to the center through hole. The method of claim 1, Electron gun for the color cathode ray tube, characterized in that the bottom through-hole is formed in the bottom surface of the first and second inlet. The method of claim 1, The inclined portion of the second inlet portion is inclined from the vertical end of the emission side to the vertical end opposite to the electron gun for color cathode ray tube. The method of claim 1, And an inclined portion of the second inlet portion is formed with a stepped portion at a predetermined depth inwardly from the vertical leading end of the exit side, and is inclined from the end of the stepped portion to the vertical end of the exiting side opposite thereto. The method of claim 5, Electron gun for a color cathode ray tube, characterized in that the planar portion is formed at each of the front end of the step portion and the vertical end of the exit side opposite to each other. The method according to any one of claims 1 to 6, The inclined portion is an electron gun for a color cathode ray tube, characterized in that inclined downward toward the center of the screen electrode. The method according to any one of claims 1 to 6, The inclined portion of the electron gun for a color cathode ray tube, characterized in that inclined downward to both vertical sides of the screen electrode. Three cathodes which are the emission sources of the electron beam; A control electrode for controlling electron beams emitted from the cathodes; It is installed adjacent to the control electrode, among the through holes formed to pass each electron beam passing through the control electrode is formed on the exit side of the through hole in the center symmetrical with respect to the central axis of the through hole is formed, On the exit side of the through-holes of the periphery, the horizontal width is smaller than the horizontal width, and based on each central axis of the through-holes, a flat portion is formed on one side, the other side inclined downward in the horizontal direction from the vertical end of the exit side A second lead portion having an inclined portion, wherein the screen electrode changes the path of the electron beam passing through the peripheral through holes; Focusing electrodes each having electron beam passing holes having a predetermined shape formed from the screen electrodes to form a plurality of auxiliary lenses; And And a final acceleration electrode disposed adjacent to the focusing electrode to form a main lens. The method of claim 9, Electron gun for the color cathode ray tube, characterized in that the second inlet portion formed in the peripheral through holes are symmetrical with respect to the center through hole. The method of claim 9, Electron gun for the color cathode ray tube, characterized in that the bottom through-hole is formed in the bottom surface of the first and second inlet. The method according to any one of claims 9 to 11, The inclined portion is an electron gun for a color cathode ray tube, characterized in that inclined downward toward the center of the screen electrode. The method according to any one of claims 9 to 11, The inclined portion of the electron gun for a color cathode ray tube, characterized in that inclined downward to both vertical sides of the screen electrode.