KR20030067094A - Electron gun for CRT - Google Patents

Abstract

PURPOSE: An electron gun is provided to achieve improved resolution of a cathode ray tube by controlling the degree of thermal expansion of electrode and removing an element having an influence on the trajectory of electron beam. CONSTITUTION: An electron gun comprises a cathode for emitting electron beams toward a phosphor screen; and a plurality of electrodes having three electron beam passing holes arranged in a horizontal line so as to control, accelerate and focus electron beams. The distance between electron beam passing holes(17) in one or more electrodes and the distance between outer electron beam passing holes(18) in the outermost portion on the horizontal line of the electrode, have a difference of 5% or lower.

Description

Electron gun for color cathode ray tube {Electron gun for CRT}

The present invention relates to an electron gun of a cathode ray tube.

The electrodes of the in-line electron gun for the cathode ray tube are mutually perpendicular to the path through which the electron beam 13 passes so that the electron beam generated from the cathode 3 can be controlled in a constant intensity to reach the fluorescent surface 15. Located at regular intervals.

Referring to the drawings in detail, as shown in FIG. 1, the first electrode 4 and the first lattice, which are common lattice of three independent cathodes 3 and three cathodes 3 which are arranged at a predetermined distance from the cathode, are formed. The second electrode 5, the third electrode 6, the fourth electrode 7, the 5-1 electrode 8-1, and the 5-2 electrode 8-2 disposed at a predetermined interval from one electrode. In the order of the sixth electrode (9), and in the order of the shield cup (10) with the BSC (bulb space connector) 11 for supporting the upper end of the electron gun to the cathode ray tube on the sixth electrode Different voltages are supplied to the three independent cathodes 3 to form a constant electron gun and to obtain a constant current value so that the cut-off voltage of each electron gun is necessarily the same.

In addition, the electron gun is a heater (2) embedded in the cathode (3) is supplied with power from the stem pin (1) generates heat and electrons are emitted from the cathode by this heat, the electron is a first electrode which is a control electrode The electron beam 13 is controlled by (4), and the electron beam 13 is accelerated by the second electrode 5 which is an acceleration electrode, and the fifth electrode 8 and the sixth electrode 9, which are main lens forming electrodes, are accelerated. After passing through the shadow mask 14 provided on the inner surface of the fluorescent surface 15, it collides with the fluorescent surface 15 to emit light.

In addition, a deflection yoke 12 for deflecting the electron beam 13 emitted from the electron gun to the entire fluorescent surface 15 is located on the outer wall of the funnel of the cathode ray tube.

2 shows an electron gun for a cathode ray tube, in which a plurality of electrodes configured to generate an electron beam and reach the fluorescent surface 15 by divergence and focusing are fixed at regular intervals by a plurality of insulating supports 16, respectively.

3A and 3B show an electrode shape of a conventional electron gun.

As shown in FIG. 3A, three electron beam through holes are horizontally formed in one plane, and a distance a ′ between the central electron beam through hole 17 and the outer electron beam through hole 18 is determined by the electrode. It is configured to be smaller than the distance b 'between the outer electron beam passing holes 18 at the outermost part on the horizontal in-line of.

In addition, as shown in FIG. 3B, the distance a 'between the central electron beam through hole 17 and the outer electron beam through hole 18 is the outer electron beam through hole at the outermost portion on the horizontal inline of the electrode. 18) larger than the distance b '.

In the conventional electron gun composed of the above electrodes, when heat is generated in a heater installed inside the cathode, electrons are emitted from the cathode by the heat, and the electrons emitted are the control electrodes of the first electrode 4 and the second electrode 5. Passing through the electron beam through hole, the heat generated from the cathode when the electron gun is operated affects each electrode made of a metal material to generate a thermal deformation of the electrode.

The thermal deformation of the electrode generated at this time changes the initial design value set for the realization of a good resolution, thereby affecting the trajectory of the electron beam 13, so that the designer cannot obtain the desired performance.

Orbits of the electron beams affected by the thermal deformation of the electrode will be described in detail with reference to FIGS. 4A, 4B, and 4C.

When one electrode receives heat, the heat is changed in thermal expansion according to the area of the electrode. As shown in FIGS. 3A and 3B, in a conventional electrode structure, the distance a 'between the electron beam passing holes and the horizontal inline of the electrode Since the distance b 'between the outer electron beam through holes 18 is different from the outermost part, thermal expansion affects the direction of the central electron beam through holes 17 when thermal expansion occurs, and thus is not concentrated in one place as shown in FIG. 4A. Instead, as shown in FIG. 4B, the trajectory of the electron beam 13 is affected.

In FIG. 4B, the outer main lens 22 moves to the center main lens unit 21 so that the electron beam distance s' is smaller than the electron beam distance s of the initial design value, so that the trajectory of the electron beam 13 As a result, the phenomenon appearing on the screen 15 results in a central portion and a faint portion of the halo, resulting in a fatal coupling to the resolution.

In addition, when the main lens part 22 on the outside moves outward from the main lens part 21 due to material factors and thickness factors of the electrode, as shown in FIG. 4C, the distance between the electron beams s ″ is initially designed. The value is greater than the distance s, which affects the trajectory of the electron beam 13.

As shown in FIG. 4C, the outer electron beam 13 is not concentrated in one place, resulting in an indefinite shape on the screen 15, thereby causing a fatal defect in the resolution of the cathode ray tube.

Therefore, when using the conventional electrode as described above, since the quality of the resolution not found in the production of the cathode ray tube is found in the operation after completion of the cathode ray tube, the important characteristics of the cathode ray tube as well as the productivity decrease due to the rise of the defective rate are important. Since it causes a decrease in phosphorus resolution, a problem occurs that causes a fatal loss in the reliability of the cathode ray tube.

Accordingly, an object of the present invention is to solve a conventional problem, and when the trajectory of the three electron beams initially set in the cathode ray tube electron gun is changed by expansion due to the thermal effect of the electron gun and formed on the screen, Halo Alternatively, the purpose of the present invention is to prevent degradation of resolution characteristics due to blooming characteristics.

1 is a longitudinal cross-sectional view of a typical cathode ray tube,

2 is a schematic view of an electron gun for a color cathode ray tube;

3a and 3b is a view showing a conventional electrode structure,

4A is an explanatory diagram of focusing of a main lens unit according to the present invention;

4B is an explanatory diagram of focusing of the main lens unit in FIGS. 3A and 3B;

4C is an explanatory diagram of focusing of a main lens unit due to material factors and thickness factors of an electrode;

5 is a view showing an electrode structure according to the present invention,

FIG. 6 is a graph illustrating a difference in thermal expansion of an electrode according to a difference between a distance between an electron beam passing hole and a distance between an outer electron beam passing hole at the outermost part on a horizontal inline of the electrode.

Explanation of symbols on the main parts of the drawings

4: first electrode 5: second electrode

6: third electrode 7: fourth electrode

12: deflection yoke 15: fluorescent surface

21: center main lens unit 22: outer main lens unit

The present invention for achieving the object as described above, for a cathode ray tube comprising a cathode for emitting an electron beam toward the phosphor screen and a plurality of electron beam through holes arranged in a horizontal line to control, accelerate and focus the electron beam In the electron gun, the distance between the electron beam through hole in at least one of the electrodes and the distance between the outer electron beam through hole in the outermost part of the horizontal in-line of the electrode is less than 5%.

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

The present invention prevents the structure of the electrode constituted by the electron gun of the cathode ray tube from being deformed by the heat generated from the cathode when the electron gun is operated, thereby preventing the influence of the trajectory of the electron beam by maintaining the distance between the initially set electron beams. It is.

Figure 5 shows the electrode structure of the electron gun according to the present invention.

The overall shape of the electrode structure according to the present invention is configured in the same manner as the conventional electrode structure, as shown in Figure 5, the distance (a) between the electron beam through hole formed in one electrode and the outermost portion on the horizontal inline of the electrode The distance b between the outer electron beam passing holes is identical.

FIG. 6 illustrates an amount of change in thermal expansion of an electrode according to a ratio between the distance a between the electron beam passing holes formed in one electrode as shown in FIG. 5 and the distance b between the outer electron beam passing holes at the outermost part of the horizontal inline of the electrode. It is a graph.

As shown in FIG. 6, when the distance a between the electron beam passing holes and the distance b between the outer electron beam passing holes at the outermost part of the horizontal inline of the electrode are the same, the amount of change in the electrode structure due to thermal expansion can be reduced.

In the actual process, the difference between the distance a between the electron beam passing holes and the distance b between the outer electron beam passing holes at the outermost part of the horizontal inline of the electrode may cause an error of about 5%. When the distance a between the through holes a and the distance b between the outer electron beam through holes in the outermost part on the horizontal inline of the electrode exceeds 5%, the change amount of the electrode due to thermal expansion increases.

Therefore, when the electrode configured to have the same distance (a) between the electron beam passing holes and the distance (b) between the outer electron beam passing holes in the outermost part on the horizontal inline of the electrode according to the present invention is expanded by the heat, the expansion by the heat Since the distance a between the electron beam passing holes and the distance b between the outer electron beam through holes at the outermost part on the horizontal inline of the electrode are not directly affected, as shown in FIG. The lens unit 22 maintains the interval s between the electron beams, which is an initial design value.

As described above, since the interval s between the electron beams, which is an initial design value, is maintained as it is, three electron beams 13 can be concentrated in one place on the screen 15, thereby improving the resolution characteristic.

In addition, it can be manufactured without any additional device and can be manufactured in the same way as in the conventional case when manufacturing an electron gun, which is advantageous in improving productivity, and the outer peripheral part of the electrode becomes smaller, so that the gap between the neck portion of the cathode ray tube becomes farther. It is possible to improve the discharge characteristics.

The present invention is to verify the effect on the plate-like electrode, it can be said that the shape of the electrode of the cap and cup shape, not one plate-shaped electrode is within the scope of the present invention.

Therefore, according to the present invention, by adjusting the distance between the electron beam through hole formed in the electrode of the cathode ray tube electron gun and the distance between the outer electron beam through hole at the outermost part on the horizontal inline of the electrode, the degree of thermal expansion of the electrode is adjusted and the By removing the factors affecting the orbit, the resolution characteristic, which is an important characteristic of the cathode ray tube, can be improved.

In addition, the size of the outer periphery of the electrode is reduced, thereby improving the discharge characteristics of the electron gun, thereby achieving an effect of simultaneously improving productivity and reliability of the cathode ray tube.

Claims (2)

An electron gun for a cathode ray tube comprising a cathode for emitting an electron beam toward a phosphor screen and a plurality of electrodes arranged in a horizontal line to control, accelerate, and focus the electron beam. And a distance difference between a distance between the electron beam through holes in at least one of the electrodes and an outer electron beam through hole in the outermost part of the horizontal inline of the electrode is 5% or less. The method of claim 1, And a distance (b) between the electron beam passing holes and the distance (b) between the outer electron beam passing holes at the outermost part on the horizontal inline of the electrode.