KR100190167B1 - Electron gun for color cathode ray tube - Google Patents

Abstract

The present invention discloses an electron gun for a color cathode ray tube.

The present invention provides a cathode comprising a three-pole portion, a control electrode and a screen electrode having three electron beam through holes, a plurality of focus electrodes forming an auxiliary lens and a main lens, and adjacent to the focus electrode and provided with a first convergence means. The present invention relates to an electron gun for a color cathode ray tube provided with a final acceleration electrode, characterized in that a second convergence means is provided on at least one focus electrode constituting the auxiliary lens, thereby improving the convergence characteristic of the electron gun. .

Description

Electron gun for colored cathode ray tube

1 is a cross-sectional view showing an electron gun for a conventional color cathode ray tube.

2 is a cross-sectional view of an electron gun for a color cathode ray tube according to the present invention.

3 is a perspective view of a focus electrode.

* Explanation of symbols for main parts of the drawings

21: cathode 22: control electrode

23: screen electrode 24: first focus electrode

25: second focus electrode 26: third focus electrode

27: final acceleration electrode

The present invention relates to an inline electron gun for a color cathode ray tube, and more particularly, to an electron gun for a color cathode ray tube with improved static convergence characteristic of converging three electron beams at one point.

Typically, an electron gun for an inline type cathode ray tube is fixed to the neck portion of the cathode ray tube and emits three electron beams of red, green, and blue signals. As shown in FIG. 1, three cathodes arranged in an inline shape ( 11), a control electrode 12 and a screen electrode 13 having three electron beam through holes formed therein, and a focus electrode 14 and a final acceleration electrode 15 constituting the main electron lens. The centers of the electron beam through holes 15R and 15B of the electron beam through holes 15R, 15G, and 15B formed in the final acceleration electrode 15 forming the main lens are static. For the correction of the convergence, the center is eccentrically outward from the center of the outer electron beam passing holes 14R and 14B formed in the focus electrode 14 by a predetermined length.

According to the conventional electron gun for color cathode ray tubes configured as described above, a predetermined voltage is applied to each electrode to form a predetermined electron lens between the electrodes. The electron beam passes through both sides of the focus electrode 14 and the final acceleration electrode 15. The electron lens formed between the balls 14R, 14B, 15R, and 15B is asymmetrically formed. Therefore, the electron beam emitted from the cathode is preliminarily focused and accelerated by a prefocus lens formed between the control electrode 12 and the screen electrode 13, and is then formed between the focus focus electrode 14 and the final acceleration electrode 15. The final lens is focused and accelerated by the main lens to be landed on the fluorescent film. In this process, the electron beams on both sides, that is, the electron beams of the red and blue signals, pass through the asymmetrically formed main lens, and the cone is directed to the electron beam side of the green signal which is the central electron beam. It will be versioned.

However, as described above, when both electron beam passing holes constituting the main lens are asymmetrically and static convergence toward the electron beam side of the center of the electron beams on both sides of the electron gun, the electron beam passing holes of the electrode on one side of the pair of electrodes forming the electron lens It is impossible to form a precise electronic lens because the centers must be staggered, and in particular, when the voltage applied to the focus electrode 14 constituting the main lens is variable, the intensity of the main lens is variable, thereby changing the convergence characteristics. . Accordingly, since three electron beams cannot be converged at one point of the fluorescent film, there is a problem that the image resolution of the cathode ray tube cannot be improved.

The present invention was created in order to solve the above-mentioned conventional problems. A color capable of converging an electron beam emitted from a cathode in multiple stages and converging at a point of a fluorescent film irrespective of a voltage change forming a main lens The purpose is to provide an electron gun in a cathode ray tube.

In order to achieve the above object, the present invention provides a cathode comprising a triode, a control electrode and a screen electrode having three electron beam through holes, a plurality of focus electrodes forming an auxiliary lens and a main lens, and adjacent to the focus electrode. In the electron gun for color cathode ray tubes provided with the final acceleration electrode provided with one convergence means, the second convergence means is provided in the at least one focus electrode which comprises an auxiliary lens.

In the present invention, the second convergence means is formed with an inlet groove whose center is eccentrically inward with respect to the center of both electron beam through holes, which is formed around the two electron beam through holes forming the auxiliary lens. The electrode piece is preferably formed by attaching an electrode piece having a through hole eccentric to the center of the electron beam through hole to a portion corresponding to the electron beam through hole on both sides of the electrode.

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

As shown in FIG. 2, the electron gun for a color cathode ray tube according to the present invention focuses and accelerates an electron beam by forming a main lens system with a cathode 21, a control electrode 22, and a screen electrode 23 constituting an anterior triode. In addition, the first, second and third focus electrodes 24, 25 and 26 and the final acceleration electrode 25 for converging the electron beams on both sides are provided.

Here, the electron beam passing holes on both sides of the three electron beam through holes 26R, 26G, 26B, and 27R, 27G, 27B are respectively formed in the third focus electrode 26 and the final acceleration electrode 27 (( 26R (26B) and (27R) (27B) are formed to be mutually offset so that a first convergence means for converging the electron beams on both sides to the electron beam side of the center is provided, and the second focus electrode 25 forming the auxiliary lens is provided. ) Is provided with a second convergence means for converging both electron beams. The second converging means has a leading centered around both electron beam passing holes 25R and 25B of the second focus electrode 25 inwardly eccentric with respect to the center of both electron beam passing holes 25R and 25B. Grooves 25R 'and 253' are formed. At this time, the inlet grooves 25R 'and 25B' are formed at both sides of the three electron beam through holes 25R 'and 25G' and 25B 'on the incident side of the second focus electrode 25 as shown in FIG. The electron beam passing holes 25R 'and 25B' are preferably formed by attaching the electrode pieces 25 'eccentrically toward the center of the electron beam passing holes 25R. A third convergence means is provided between the screen electrode 23 and the first focus electrode 24, and the third convergence means is provided with electron beam passing holes 24R on both sides of the first focus electrode 24 ( The center of 24B is eccentrically outward from the center of both electron beam through holes 23R and 23B of the screen electrode 23. Although not shown in the drawing, a predetermined voltage is applied to each electrode.

Referring to the operation of the electron gun for the color cathode ray tube according to the present invention configured as described above are as follows.

In the electron gun for color cathode ray glasses according to the present invention, a predetermined potential is applied to each electrode to form a prefocus lens between the screen electrode 23 and the first focus electrode 24, and the first, second, and third focus electrodes 24. ), (25), and (26) are different depending on the voltage application method, but an auxiliary lens including an asymmetric lens is formed, and a main lens is formed between the third focusing electrode 26 and the final acceleration electrode 27. Will be formed.

At this time, the third convergence means formed between the screen electrode 23 and the first focus electrode 24, that is, both electron beam through holes 23R, 23B, 24R, 24B formed on the above-described electrodes, respectively Since the centers are shifted from each other, the prefocus lenses formed on the electron beam through holes 23R, 235 and 24R, 24B on both sides are formed asymmetrically. The center of the electron beam through hole 25R (the second converging means formed in the second focus electrode 25, that is, around the incident side of the two electron beam through holes 25R and 25B of the second focus electrode 25) Since the inlet grooves 25R 'and 25B' which are eccentric inward with respect to the center of 25B are formed, the auxiliary lenses formed on both sides of the electrode are formed asymmetrically.

Therefore, the two electron beams emitted from each cathode 21 are converged to the central electron beam in the process of being focused by the prefocus lens, and are secondaryly converged while passing through the auxiliary lenses. Will be converged.

Therefore, since the electron beams on both sides emitted from the cathode 21 are converged in multiple stages, the focus voltage applied to the third focus electrode 26 constituting the main lens is changed so that the overall convergence characteristic of the electron gun is lowered. You can prevent it.

As described above, the electron gun for the cathode ray tube of the present invention can improve static convergence characteristics by concentrating both electron beams toward the center electron beam side, and further, has the advantage of improving the resolution of the cathode ray tube employing the electron beam.

Claims (4)

A cathode comprising a triode, a control electrode and a screen electrode having three electron beam through holes, a plurality of focus electrodes forming an auxiliary lens and a main lens, and adjacent to one of the focus electrodes, and provided with a first convergence means. An electron gun for a color cathode ray tube comprising a final acceleration electrode, wherein a second convergence means is provided in at least one focus electrode constituting the auxiliary lens. The color cathode ray beam according to claim 1, wherein the second convergence means is formed of an inlet groove whose center is eccentrically inward with respect to the center of the two electron beam through holes around the two electron beam through holes forming the auxiliary lens. Tolerance gun. The method of claim 1, wherein the second convergence means is attached to the electrode piece having a through hole eccentric to the center of the electron beam through hole in a portion corresponding to the electron beam through hole on both sides of the focus electrode. Electron gun for colored cathode ray tubes. The electron gun for color cathode ray tube according to any one of claims 1 to 3, wherein the electron beam passing holes on both sides of the screen electrode are eccentric inward from the center of the electron beam passing holes on both sides of the focus electrode provided adjacent thereto.