KR950002743B1 - Electron gun for c-crt - Google Patents

Abstract

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Description

Electron gun for colored cathode ray tube

1 is a sectional view of an electron gun for a conventional cathode ray tube,

2 is a diagram illustrating an electrode of a conventional main lens, in which (a) is a front view and (b) is a sectional view.

3 is a diagram illustrating another electrode constituting the conventional main lens, wherein (a) is a front view and (b) is a sectional view.

4 is a cross-sectional view of an electron gun for a cathode ray tube according to the present invention,

5 is a diagram showing an electrode forming a main lens of a cathode ray tube electron gun according to the present invention, where (a) is a front view and (b) is a sectional view.

6 shows the change of the cross-sectional shape of the electron beam according to the center movement of the two independent small-diameter electron beam passing holes forming the main lens.

* Explanation of symbols for main parts of the drawings

11 cathode 12 control electrode

13 screen electrode 15 focus electrode

16: final acceleration electrode 18: protrusion

15R, 15G, 15B, 16R, 16G, 16B: Independent small diameter electron beam through hole

The present invention relates to a cathode ray tube, and more particularly, to an electron gun for a cathode ray tube mounted on a neck portion of a cathode ray tube to emit hot electrons.

In general, a cathode ray tube electron gun has a panel in which red, green, and blue fluorescent films are formed in a predetermined pattern, and a shadow mask frame assembly is provided so as to be spaced apart from the fluorescent film, and is sealed to the panel. A funnel having an electron gun and a deflection yoke, respectively, is provided inside and outside the neck portion.

In the cathode ray tube configured as described above, three electron beams emitted from the electron gun are selectively landed on the red, blue, and green coronal membranes, thereby reproducing a desired image and color. Focus is important to determine the size of the electron gun and electron gun to determine the convergence property to focus the three electron beams in one place.

FIG. 1 shows an example of an electron gun that influences such fogger and convergence characteristics.

This is described in U.S. Patent No. 4,370,592 and shown in FIG. 1, which comprises a cathode 2, a control electrode 3 and a screen electrode 4 which form an anterior tripolar portion, a focus electrode 5 constituting a main lens system and The final acceleration electrode 6 is provided, and the emission side and the incident side of the focus electrode 5 pass through the large-diameter electron beam through which the red, blue, and green electron beams pass through, as shown in FIG. The first electrode members 5a and 6a having the holes 5H and 6H formed therein and a predetermined length from the edges of the large-diameter electron beam passing holes 5H and 6H of the first electrode members 5a and 6a. The second electrode member 5b provided inside the first electrode member 5a and 6a and having three independent small-diameter pendulum beam through holes 5R, 5G, 5B, 6R, 6G, and 6B. It consists of (6b).

As a predetermined potential is applied to the focus electrode 5 and the final accelerating electrode 6 configured as described above, a main lance is formed therebetween, and the large-diameter electron beam passing holes 5H and 6H constituting the main lens are formed. Because of the vertical and horizontal asymmetry, the focusing components in the vertical and horizontal directions of the respective electron beams were different, so that each electron beam spot landing on the fluorescent surface could not be made uniform.

In order to solve the problems as described above, the large-diameter electron beam through hole 6H of the final acceleration electrode 6 is conventionally described in US Patent Nos. 4,388,552 and 4,370,592 and shown in FIG. The width W2 of both edges is formed wider than the width W1. That is, the large-diameter electron beam passing hole 6H has a projection 6P in which a portion corresponding to the green independent small-diameter transfer beam passing hole 6G protrudes a predetermined length.

The large diameter electron beam through hole 6H of the final accelerating electrode 6 configured as described above can reduce spherical aberration due to the relatively low magnification, but when the beam current is high, the center portion of the large diameter electron beam through hole 6H is high. Since the electron beam is attracted by the protrusion 6P protruding from the force and a corresponding force is applied to the electron beam, the electron beam spot which is lit on the fluorescent film is distorted.

The present invention has been made to solve the above problems, it is possible to prevent the electron beam spot landing on the fluorescent film is distorted, and to provide an electron gun for the cathode ray tube that can prevent the deterioration of the focus characteristics in the peripheral portion of the fluorescent film The purpose is.

Another object of the present invention is to provide an electron gun for a cathode ray tube which can reduce astigmatism of both electron beams and prevent the spreading occurring in the horizontal direction of the electron beam spot.

In order to achieve the above object, the present invention provides a large-diameter electron beam through-hole having a protrusion through which an electron beam of red, green, and blue signals pass through, and an edge of a central portion through which the electron beam of the green electron beam signal protrudes protrudes to a predetermined width. An electrode layer for a cathode ray tube comprising a first electrode member and a second electrode member fixed inside the first electrode and having three independent small diameter electron beam through holes formed therein, the eccentric distance of the independent small diameter electron beam through holes. When A is the distance that the center of the two independent small-diameter electron beam passing holes moves from the center to the independent small-diameter electron beam passing hole, the value of A satisfies 0,15S <A <0.35S. It is characterized by that.

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

As shown in FIG. 4, the cathode ray tube electron gun according to the present invention has the cathode 11, the control electrode 12, the screen electrode 13, and the focus electrode 15 forming the main lens and the final acceleration as the prepolar triode. An electrode 16 is provided, and the electrodes located on the emission side of the focus electrode 15 and the incident side of the final acceleration electrode 16 have a large diameter through which three electron beam signals pass through as shown in FIG. First electrode members 15a and 16a formed with electron beam passing holes 15H and 16H, and projections 18 having a predetermined length extending in the center direction of the upper and lower edges of the large-diameter electron passing hole; The second electrode member 15b fixedly installed in the electrode members 15a and 16a and having three independent small-diameter electron beam passing holes 15R, 15G, 15B, 16R, 16G, and 16B. 16b). Herein, the independent small diameter electron beam passing holes positioned at both sides of the independent small diameter electron beam passing holes 15R, 15G, 15B, 16R, 16G and 16B formed in the second electrode members 15b and 16b ( The centers of the 15R, 15B, 16R, and 16B are moved from the center to the independent small-diameter electron beam passing holes 15G and 16G by the predetermined distance A. Here, the distance A has a value satisfying the following floating equation when the eccentric distance of the independent small diameter electron load passing hole is S.

Floating type; 0.15S <A <0.35S

The operation of the cathode ray tube electron gun configured as described above is as follows.

In the electron beam gun for cathode ray light according to the present invention, as a predetermined voltage is not applied to each electrode, a prefocus lens is formed between the screen electrode 13 and the focus electrode 15, and the focus electrode 15 and the final acceleration electrode 16 are formed. The main lens is formed between the? Therefore, the electron beam emitted from the electron gun is prefocused and accelerated by the prefocus lens and finally focused and accelerated by the main lens to be landed at each fluorescent point of the fluorescent film, wherein the electron beam spot landing at each fluorescent point is focused. The first electrode members 15b and 16b of the electrode 15 or the final acceleration electrode 16 have independent centers of independent small-diameter electron beam through holes 15R, 15B, 16R, and 16B on both sides. Since the predetermined length is moved toward the small-diameter electron beam passing holes 15G and 16G, it can be prevented from being crushed when landing on the fluorescent film.

That is, the centers of the two independent small-diameter electron beam passing holes l5R, 15B, 16R and 16B formed in the second electrode members 15b and 16b are centered and independent small-diameter electron beam passing holes 15G and 16G. Since both sides are moved by a distance between 0.15 times and 0.35 times the eccentric distance S, both sides are separated from the protrusions 18 formed at the center of the large-diameter electron beam passing holes 15H and 16H of the first electrode members 15a and 16a. It is possible to prevent the penetration of the electric field moved to the aperture electron beam passing hole side, thereby preventing distortion of the electron beam spot landing on the fluorescent film.

The present inventors experimented the relationship between the eccentric distance (the eccentricity is 5.6mm applied) and the distortion state of the spot of the electron beam with respect to the amount of movement of the center of the two independent small diameter electron beam passing holes toward the center of the independent small diameter electron beam passing hole. As a result, the following table 6 was obtained.

As can be seen from the table shown in FIG. 6, when the A / S value is between 0.17 and 0.35, it can be seen that the cross section of the electron beam landing on the fluorescent film has a circular shape without distortion. .

As described above, the electron gun for the cathode ray panel of the present invention prevents the electron beam spot landing on the fluorescent film from being distorted by moving the center of the outer electron beam through hole of the second electrode member constituting the main lens to a predetermined length in the center of the independent small diameter electron through hole. In addition, it is possible to obtain an electron beam spot having a uniform size in the conventional fluorescent film, which has the advantage of improving the resolution of the cathode ray tube employing the same.

Claims (1)

A first electrode member having a large-diameter electron beam through-hole having a protruding portion protruding a predetermined width from an edge of a center portion through which the electron beam of the red, green, and blue signal passes, and the first electrode of the first electrode; In a cathode ray gun electron beam fixed to the inside and including a second electrode member formed of three independent small diameter electron beam through holes, the eccentric distance of the independent electron beam through holes is S and the centers of the two independent small diameter electron beam through holes are An electron gun for cathode ray tubes, wherein the value of A satisfies a floating 0.15S &lt; A &lt; 0.35S when the distance traveled from this to the center independent small-diameter electron beam passing hole side is A.