KR20010009077A - Electrode and electron gun for CRT utilizing the same - Google Patents

Abstract

PURPOSE: An electron gun for a CRT(Cathode Ray Tube) with electrodes is provided to reduce aberration of electron beams caused by large-diameter holes, to change the sectional area of electron beams to a desired shape and to improve focusing of electron beams by reducing focus voltage difference between electron beams passing the holes. CONSTITUTION: A prefocus lens is formed between a control electrode and screen electrode(53) while a main lens is between the first and second condensing electrodes(60,70). The main lens forms an electron lens and the electron beams pass through the electron lens as an equipotential surface is formed in a normal direction of an electric force. The electron beams are influenced by different condensing elements through central and both small-diameter holes(63G,73G,63R,63B,73R,73B) because of asymmetric large-diameter holes(61,71). The focusing of electron beams is reduced by induction of focus voltage difference. The electron gun obtains distortion and extension of the pass holes by difference between horizontal and vertical diffusion force through a horizontal portion around the small-diameter holes and a curve portion at both sides. Lips(65,75) are formed on the small-diameter holes toward the electron beams to reduce influence by distortion of diffusion force of the large-diameter holes.

Description

Electrode and electron gun for CRT utilizing the same}

The present invention relates to a cathode ray tube, and more particularly, to an electrode for forming a large-diameter electron lens and an electron gun for a cathode ray tube using the electrode.

In general, in the electron gun for cathode ray tubes, spherical aberration and focus characteristics are greatly influenced by the main lens, so that the aperture of the main lens should be formed as large as possible to obtain good focus characteristics.

However, in the inline electron gun, three electron beam through holes are formed inline at least on two electrodes forming the electron lens, and the diameter of the neck portion of the funnel to which the electron gun is mounted is limited, so that the centers of two adjacent electron beam through holes are provided. It is impossible to make the electron beam through hole diameter larger than the distance between the electrodes (hereinafter referred to as “eccentric distance”).

The construction of an electron gun for improving spherical aberration in a conventional main lens is disclosed in US Pat. No. 4,370,592 and shown in FIG.

As shown, burring portions 1b and 2b are formed at the edge of the exit surface 1a of the focus electrode 1 and the entrance surface 2a of the final acceleration electrode 2, and a large diameter having a predetermined depth in the center portion thereof. Electron beam passing holes 1H and 2H are formed. Further, in the large-diameter electron beam passing holes 1H and 2H, small-diameter electron beam passing holes 1H 'and 2H' through which R, G, and B electron beams pass independently are formed.

When the electron beams pass through the main lens formed by the focus electrode 1 and the final acceleration electrode 2, the large-diameter electron beam through holes 1H and 2H are asymmetric, so they pass through the central small-diameter electron beam through holes. Since the vertical and horizontal focusing components of the electron beams passing through one electron beam and the small-diameter electron beam passing holes on both sides are different from each other, an electron beam spot landing on the fluorescent surface cannot be uniformly formed. That is, as shown in FIG. 2, both side electron beams RB (BB) having passed through the large-diameter electron beam passing holes 1H and 2H of the focus electrode 1 or the final acceleration electrode 2 have a low voltage or Close to the burring portions 1b and 2b where the high voltage is distributed, and the central electron beam GB is relatively far from the burring portions 1b and 2b. Therefore, the electron beams RB (BB) at both sides are relatively strongly focused and the electron beam GB at the center is weakly focused.

Further, since the distance between the both side electron beams RB (BB) and the burring portions 1b and 2b is different depending on the direction, the horizontal focusing force and the vertical focusing force on the electron beam are different from each other. In addition, since the vertical distance between the central electron beam GB and the burring portions 1b and 2b is closer than the horizontal distance, the electron beam receives a strong vertical focusing force. In addition, the central electron beam GB receives divergence in the diagonal direction of the large-diameter electron beam passing holes 1H and 2H. Therefore, the electron beams RB (BB) at both sides passing through the main lens have a substantially triangular cross section, and the central electron beam GB has a shape in which its cross section radially protrudes, thus being uniform throughout the fluorescent surface. The electron beam cross section cannot be obtained.

In particular, since the size of the small-diameter electron beam passing holes (1H ', 2H') is limited by the neck portion diameter of the cathode ray tube, there is a limit to increasing the eccentric distance between the small-diameter electron beam passing holes (1H ', 2H'). have. In addition, since the diameter of the neck portion has recently been reduced in order to reduce the deflection power, there is a problem in that the spacing between the small-diameter electron beam passing holes 1H 'and 2H' is also reduced, so that spherical aberration and focus characteristics are deteriorated.

The electrode configuration of the electron gun for solving the above problems is disclosed in US Patent No. 5,414,323. As shown in FIG. 3, the electrode of the electron gun was provided with an electrode piece 12 in the center of the outer electrode 11 having the large-diameter electron beam passing hole, and a long-sized small-diameter electron beam passing hole in the center of the electrode piece 12 ( 13) is formed, and both edges of the electrode pieces 12 are drawn in a semi-ellipse shape so as to form side electron beam through holes 14 and 15.

By forming the central small-diameter electron beam passing hole in the vertical shape, the astigmatism caused by the large-diameter electron beam passing hole is canceled out. However, in the electrode, the 8-pole comma aberration of the center electron beam through hole and the 6-pole comma aberration of both electron beam through holes cannot be easily corrected.

Another example of a conventional large diameter electrode is disclosed in US Pat. No. 4,626,738. As shown in FIG. 4, the electrode includes an external electrode 21 having a large-diameter electron beam through hole, and an inner electrode formed in the external electrode 21 and having a polygonal small-diameter electron beam through hole 22R, 22G, 22B. Electrode 22. Here, although the aberration generated by the large-diameter electron beam passing hole can be corrected by the polygonal electron beam passing holes 22R, 22G, and 22B, the polygonal electron beam passing hole is not easy to manufacture.

The present invention has been made to solve the above problems, and an object thereof is to provide an electrode of an electron gun for a cathode ray tube that can easily correct aberration of an electron lens formed by a large-diameter electron beam passing hole and improve focus characteristics. .

Another object of the present invention is to provide an electron gun for a cathode ray tube which can reduce astigmatism by compensating for the distortion of an electron beam due to a voltage difference acting on three electron beam through holes arranged in an inline phase.

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

2 is a front view showing an electrode of a conventional electron gun, showing a cross section of an electron beam.

3 and 4 are front views showing other examples of the conventional electron gun electrode,

5 is a cross-sectional view showing an electrode forming a main lens of an electron gun according to the present invention;

6 is an exploded perspective view showing an extract of an electrode according to the present invention;

7 is a perspective view showing another embodiment of the electrode according to the present invention.

In order to achieve the above object, the electrode of the cathode ray tube electron gun of the present invention

An outer rim electrode member having a large-diameter electron beam passing hole through which three electron beams pass; To be installed inside the outer rim electrode member,

Upper and lower edges are located between the horizontal part formed on both sides of the horizontal portion and the horizontal electron beam through-holes on both sides having a curved portion connecting the horizontal portion and the electron beam through-holes on both sides and the upper and lower edges through the central electron beam formed with a lip extending in the traveling direction of the electron beam The ball is characterized in that it comprises an internal electrode member formed in an inline shape.

In the present invention, the horizontal length and the vertical length of the electron beam through hole is formed to be the same, and the electron beam through hole in the center is formed in an elongated shape.

The electron gun for the color cathode ray tube of the present invention for achieving the above object comprises a cathode control electrode and a screen electrode constituting the triode, and a focusing electrode which is installed adjacent to the screen electrode to form at least one electron lens,

An outer rim electrode member having a large-diameter electron beam passing hole through which the three electron beams pass through the focusing electrodes is installed inside the external electrode, and has a horizontal portion formed at upper and lower edges and a curved portion connected to the horizontal portion at both sides of the horizontal portion. The central electron beam through-hole having a lip extending between the electron beam through-holes on both sides of the excitation and the electron beam through-holes on both sides and extending in the traveling direction of the electron beam on the upper and lower edges includes an inner electrode member formed in an inline shape.

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

An electron gun for a cathode ray tube employing an electrode according to an embodiment of the present invention includes a cathode, a control electrode, and a screen electrode constituting a triode, and includes at least one pair of first and second focusing electrodes for forming an auxiliary and / or main lens. Include them. A predetermined voltage is applied to the cathode and the electrodes, respectively. As an example, a voltage of 0 to 200 V may be applied to the control electrode, and a voltage of 200 to 700 V may be applied to the screen electrode, and an inner conductive film of a cathode ray tube may be provided at the first focusing electrode located on the cathode side. A voltage of 28 to 30% of the voltage applied to the second focusing electrode to which the same voltage is applied is applied. Here, the dynamic focus voltage synchronized with the deflection signal may be applied to the first focusing electrode positioned on the side positioned on the cathode side. A voltage of 25 to 30 KV is applied to the second focusing electrode.

As shown in FIGS. 5 and 6, the first and second focusing electrodes include outer rim electrode members 62 and 72 having large diameter electron beam passing holes 61 and 71 through which three electron beams pass. The inner electrode member 63 is provided inside the outer rim electrode members 62 and 72, and is formed with independent small-diameter electron beam passing holes 63R, 63G, 63B, and 73R, 73G, 73B. (73).

By forming the horizontal centers of the large-diameter electron beam passing holes of the respective external electrodes to be offset from each other, the convergence characteristics between the three battery beams can be adjusted.

Independent small-diameter electron beam passing holes positioned at both sides of the three independent small-diameter electron beam passing holes 63R, 63G, 63B and 73R, 73G and 73B respectively formed in the internal electrodes 63 and 73 ( The horizontal portions 63RH, 73RH, 63BH, and 73BH, which are parallel to each other, are formed at the upper and lower edges, and the upper and lower horizontal portions are formed at both edges of the independent small-diameter electron beam passing hole. A central small diameter located between the electron beam passing holes 63R, 63B, 73R, and 73B on both sides; The upper and lower edges of the electron beam through holes 63G and 73G are formed with ribs 65 and 75 extending in the traveling direction of the electron beam, where the horizontal length and the vertical length of the electron beam through holes formed on both sides are the same length. It is preferable to have.

In another embodiment of the focusing electrode according to the present invention, as shown in FIG. 7, three independent small-diameter electron beam passing holes are lip 63RL, 63GL, 63BL, 73RL, 73GL, which are mutually parallel to the upper and lower edges, respectively. 73BL, and curved portions are formed at both edges of the three electron beam through holes. Here, the lengths of the lips 63GL, 73GL formed at the center of the lips 63RL, 63GL, 63BL, 73RL, 73GL, and 73BL formed at the upper and lower portions of the three independent electron beam passing holes are located at both sides. It is formed longer than the lengths of the lips 63RL, 63BL, 73RL, 73BL of the electron beam passing hole. In addition, the lips 63RL, 63BL, 73RL, 73BL formed at upper and lower edges of both electron beam passing holes are preferably formed to have the same length.

The operation of the electrode of the electron gun according to the present invention configured as described above and the electron gun for color cathode ray tube employing the electrode will be described in detail as follows.

As described above, a predetermined voltage is applied to the cathode constituting the electron gun and the respective electrodes. When voltage is applied as described above, a prefocus lens is formed between the control electrode and the screen electrode, and a main lens is formed between the first and second focusing electrodes.

The main lens formed between the first and second focusing electrodes 60 and 70 has an equipotential surface in the normal direction of the electric line of force formed between the first and the second focusing electrodes 60 and 70. Is formed, and the electron beams pass through this electron lens.

Here, as described above, since the large-diameter electron beam passing holes 61 and 71 are asymmetric, they pass through the central small-diameter electron beam passing holes 63R, 63G, 63B and 73R, 73G and 73B. The vertical focusing component and the horizontal focusing component of the electron beams passing through one electron beam and small-diameter electron beam passing holes 63R, 63B, and 73R, 73B on both sides are different, respectively, so that the electron beams have different focusing and diverging forces, respectively. Will receive. That is, the horizontal distance and the diagonal distance between the central electron beam passing through the large-diameter electron beam passing hole 61 and the edge of the electron beam passing hole in which low voltage and high voltage are distributed are relatively far, so that the electron beam is large in the horizontal direction and the diagonal direction. You will receive divergence. This action causes a difference in focus voltage between the three electron beams, thereby degrading the focus characteristic between the three electron beams.

However, the electron gun passes through the large-diameter electron beam because the independent small-diameter electron beam passing holes positioned at both sides of the first and second focusing electrodes 60 and 70 constituting the main lens have horizontal portions formed at upper and lower edges and curved portions formed at both sides thereof. Distortion and enlargement effect of electron beam through hole can be obtained according to the difference in the divergence power in the horizontal and vertical direction of the ball.

In addition, since the ribs 65 and 75 are formed in the independent small-diameter electron beam passing holes 63G and 73G located at the center, the ribs 65 and 75 are formed in the advancing direction of the electron beam. The effects of distortion can be reduced.

As shown in FIG. 7, when lips 63RL, 63GL, 63BL, 73RL, 73GL, and 73BL are formed at the upper and lower edges of the three electron beam through holes, ribs formed on the upper and lower parts of both electron beam through holes, respectively. By (63RL) 63BL and 73RL (73BL), it is possible to compensate for the distortion caused by the asymmetry difference between the vertical length and the horizontal length of the large-diameter electron beam passing hole. In particular, since the length of the lip formed at the edge of the electron beam passing hole in the center is longer than the length of the lip formed at the edges of the electron beam passing holes in both sides, it is possible to exclude the influence of the non-uniform electric field on the electron beam located at the center.

According to the electrode of the electron gun for color cathode ray tube according to the present invention, it is possible to reduce the aberration of the electron beam caused by the large-diameter electron beam passing hole, and has the advantage of changing the cross-sectional shape of the electron beam to a desired shape. In particular, it is possible to improve the focus characteristic of the electron beam by reducing the difference in focus voltage of the electron beams passing through the large-diameter electron beam passing hole.

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

Claims (6)

An outer rim electrode member having a large-diameter electron beam passing hole through which three electron beams pass; To be installed inside the outer rim electrode member, The upper and lower edges are formed between the electron beam passing holes on both sides having horizontal portions formed on both sides of the horizontal portions and connecting the horizontal portions, and the ribs extending between the electron beam passing holes on both sides and extending in the advancing direction of the electron beam on the upper and lower edges. The electrode of the electron gun, wherein the formed central electron beam passing hole includes an internal electrode member formed in an inline shape. The method of claim 1, Electrodes of the electron gun, characterized in that the horizontal length and the vertical length of the two electron beam passing holes are formed to be the same, and the electron beam passing hole in the center is formed in a longitudinal shape. The method of claim 1, Electrodes of the electron gun, characterized in that the ribs are formed on the upper and lower edges of the electron beam passing holes on both sides. A cathode control electrode and a screen electrode constituting the triode, and focusing electrodes disposed adjacent to the screen electrode to form at least one electron lens, The outer rim electrode member having the large-diameter electron beam passing hole through which the three electron beams pass through the focusing electrodes is installed inside the outer electrode, and is positioned at both sides of the horizontal part formed at the upper and lower edges and connects the horizontal parts. A central electron beam through-hole having a lip extending between the two electron beam through-holes having curved portions and the electron beam through-holes on both sides and extending in the traveling direction of the electron beam at upper and lower edges includes an inner electrode member formed in-line. Electron gun for color cathode ray tube to say. The method of claim 4, wherein Electron gun, characterized in that the horizontal length and the vertical length of the two electron beam through hole is formed to be the same, and the electron beam through hole in the center is formed in a longitudinal shape. The method of claim 4, wherein Electron guns, characterized in that the ribs are formed on the upper and lower edges of the electron beam through hole on both sides.