KR20010017583A - Electron gun for color cathode ray tube - Google Patents

Abstract

PURPOSE: An electron gun for a color cathode ray tube is provided to enhance a resolution of a screen by optimizing a shape of an outer electronic beam on the screen due to the collective force unconcerned with a direction. CONSTITUTION: The electron gun for a color cathode ray tube includes a plurality of electron emitting means emitting an electronic beam, three electrodes being consisting of a plurality of electrodes for controlling a quantity of electronic beams, main lens forming electrodes for collecting the electronic beam on the screen, openings(17,19) for allowing the electronic beam to pass through being formed on the opposite surfaces of the electrodes, and inner electrodes(18,20) fixed at positions spaced from the openings(17,19) at a predetermined distance. The openings(17,19) are formed at the focus electrode(14) or the anode electrode. At this time, inner parts of the openings for allowing the outer electronic beam to pass through are formed as a part of a circle, respectively. One axis perpendicular to the in-line meets with the above openings. At this time, a radius of curvature of the above openings decrease or is increased along a line extending between the axis and the in-line.

Description

Electron gun for color cathode ray tube

The present invention relates to an electron gun used in a color cathode ray tube or a high-definition industrial monitor, and more particularly, to a structure of an electrode forming a main lens in an electron gun.

FIG. 1 is a side view showing a part of a general color cathode ray tube, in which a cathode ray tube is disposed on an inner side of a panel 1 coated with red, green, and blue fluorescent materials, and is disposed in close proximity to an inner side of the panel. 2) a shadow mask (3) which serves as a color selection role, a funnel (4) fixed to the rear of the panel, and an electron gun mounted on the neck portion (4a) of the funnel to scan the electron beam (2) to the screen side ( 5) and a deflection yoke 6 or the like provided on the outer circumferential surface of the neck portion to deflect the electron beam emitted from the electron gun in a vertical or horizontal direction.

Each electrode of the electron gun 5 applied to the cathode ray tube is arranged in-line perpendicular to the path through which the electron beam passes so that the electron beam generated from the cathode can be controlled to a constant intensity and reach the screen.

Referring to this in more detail with reference to the accompanying Figure 2, the electron gun (5) is a heater (7) is built in each of the three negative electrodes (8) arranged side by side horizontally and independently of each other, and a predetermined distance from the cathode The first electrode 9 is disposed to be maintained to control the hot electrons generated from the cathode, and the first electrode 9 is arranged to be maintained at a predetermined distance from the first electrode and is collected on the electron emission material surface (not shown) of the cathode 8. A third electrode in the axial direction so as to form a second electrode 10 serving to accelerate and accelerate the hot electrons and a electrostatic focusing lens for focusing the electron beam on the fluorescent surface 11 applied to the panel 1. 12), the fourth electrode 13, the fifth electrode 14, and the sixth electrode 15 are sequentially arranged at regular intervals, and the shield cup 16 is disposed on the upper portion of the sixth electrode 15. It is fixed and the shield cup has an electron gun (5) and neck (4a) The electrically connected to giving (Bulb Space Connector) 3 B.S.C of which serves to secure the electron gun in the neck portion is fixed.

Each of the electrodes is fixed by a pair of bead glass (not shown) which is an insulating material.

The process in which the electron beam 2 starting from the cathode 8 of the electron gun 5 having the above structure reaches the screen will be described in more detail as follows.

When the heater 7 embedded in the cathode 8 receives power from the stem pin and generates heat, electrons are emitted from the cathode 8 by the heat generation. The electron beam 2 thus emitted is the first electrode (the control electrode). The amount is controlled by 9) and accelerated by the second electrode 10 which is an acceleration electrode.

A voltage of about 1,000 V or less is applied to the second electrode 10 and the fourth electrode 13, and the third electrode 12 and the fifth electrode (hereinafter referred to as a “focus electrode”) 14 are formed of a second electrode. A voltage corresponding to about 20 to 40% of the voltage applied to the six electrodes (hereinafter referred to as "anode electrodes") is applied.

The electron beam 2 is a shear formed between the electrostatic lens formed between the second electrode 10 and the third electrode 12 and between the third electrode 12, the fourth electrode 13 and the focus electrode 14. Partial focusing and acceleration are achieved by the focusing lens, and the incident angle at which the electron beam is incident on the main lens side is determined.

When a high voltage of about 20,000 V or more is applied to the anode electrode 15 and a voltage corresponding to about 20 to 40% of the anode electrode 15 is applied to the focus electrode 14 provided at a distance of about 0.8 mm or more from the anode electrode. Since the electrostatic focusing lens (main lens) is formed between the two electrodes, the electron beam is focused and accelerated while passing through the main lens.

The main focused and accelerated electron beam 2 passes through the shadow mask 3 provided in close proximity to the fluorescent surface 11 and is color-coded to collide with the fluorescent surface 11 to emit phosphors, thereby reproducing the screen.

As described above, when the electron beam 2 emitted from the electron gun 5 leaves the electron gun and proceeds to the screen side, the deflection yoke 6 installed on the neck portion 4a deflects the electron beam vertically and horizontally over the entire area of the screen. Let it be.

In the above-described operation, hot electrons in the cathode 8 are focused by the capacitive focusing lens to form a screen, where the sharpness of the electron beam spot on the screen depends on the following three components.

Where Dx: magnification component of the crossover point by the magnification of the electrostatic focusing lens

Dsa: electron beam dispersion component due to spherical aberration of main lens

Dsc: electron beam dispersion component by space charge effect

Among them, spherical aberration has a great influence on the focus characteristics of the electron gun, and therefore, an effective large-diameter electron gun is used to reduce spherical aberration and improve resolution. FIG. 3 shows an example of the electrostatic focusing lens unit in the effective large-diameter electron gun. It was.

Although the figure is shown in an exploded manner for the sake of understanding, in practice, the focus electrode 14 and the anode electrode 15 face each other.

An inner electrode having a common opening 17 in the form of a race track through which three electron beams pass in common in the focus electrode 14 and three independent electron beam through holes 18a are formed in the focus electrode 14. (18) is fixed.

In addition, a common opening 19, such as a chain linnk, through which three electron beams pass in common, is formed in the anode electrode 15, which is disposed to face the focus electrode 14 at a distance of 0.8 to 1.3 mm. The inner electrode 20 having three independent electron beam through holes 20a is fixed inside the anode electrode 15.

When a high voltage of about 20,000 V is applied to the anode electrode 15 and a voltage of about 5,000 to 10,000 V is applied to the focus electrode 14, an electrostatic lens is formed between the two electrodes.

At this time, each of the openings 17 and 19 formed in the focus electrode 14 and the anode electrode 15 has a smaller diameter in the vertical direction than the diameter in the horizontal direction (array of the three electron beams) and thus has a stronger focusing force in the vertical direction. Have

However, the weakened electric field that penetrates through the openings 17 and 19 of the focus electrode 14 and the anode electrode 15 is horizontal focusing force and vertical collecting force by inner electrodes 18 and 20 fixed in each electrode. The speed will remain somewhat similar.

In addition, the outer electron beams 2a and 2c are collected toward the central electron beam 2b by an electric field formed in the common openings 17 and 19 of the focus electrode 14 and the anode electrode 15, which is called “static”. Convergence ".

The moving speed of the electron beam in the electric field can be expressed by the following equation.

Where v is the velocity of electrons (m / sec)

e: Charge amount of electron (1.6 × 10 ^-19 Coulomb)

m: mass of electrons (9.1 × 10 ^-31 Kg)

V: potential

According to the above equation, since the moving speed of the electron beam is proportional to the square root of the voltage, the electron beam moves faster in the anode electrode 15 having a higher potential, and thus the anode electrode than the time focused in the focus electrode 14. The time taken for divergence in (15) is shortened.

That is, the focusing action by the focus electrode 14 is stronger than the diverging action by the anode electrode 15.

When the focus electrode 14 and the anode electrode 15 have substantially the same dimensions, in order to properly focus the electron beam in the vertical direction, the opening vertical diameter of the anode electrode 15 is generally designed to be smaller than the opening vertical diameter of the focus electrode 14. You must

In addition, the opening vertical diameter at the position of the center electron beam 2b of the anode electrode 15 must be smaller than the diameter of the opening at the position of the outer electron beams 2a and 2c, so that the gap between the center electron beam 2b and the outer electron beams 2a and 2c. The uniform focusing power can be obtained.

In addition, the outer electron beams 2a and 2c show a difference in the focusing force in the central electron beam direction and the opposite focusing force relative to the center of the outer electron beams 2a and 2c due to the asymmetry of the passage path. (coma) is called aberration.

In order to solve the coma aberration of the outer electron beams 2a and 2c, the outer electron beam through holes of the inner electrodes 18 and 20 are eccentrically designed to be eccentrically outward from the traveling center of the electron beam.

FIG. 4 is a diagram illustrating the overlapping of FIG. 3 for convenience of description, and the anode electrode 15 is indicated by a dotted line.

The horizontal end of the opening 17 of the focus electrode 14 and the horizontal end of the opening 19 of the anode electrode 15 generally coincide to obtain the maximum aperture, but the vertical diameter of the opening is the anode electrode 15 of the focus electrode. Less than 14

The horizontal focusing and diverging force by the electrodes is closely related to the vertical diameter of the opening, and the number of the openings 19 formed in the anode electrode 15 is larger than that of the opening 17 formed in the focus electrode 14. When the diameter is made smaller, the divergence force in the vertical direction is increased, but the inflow of the electric field from the opening 17 of the focus electrode 14 facing each other is weakened, thereby weakening the divergence force in the horizontal direction by the anode side inner electrode 20. Can be.

In the conventional electron gun, the electron beam can be designed to focus properly in the horizontal and vertical directions on the screen, but the center axis FC and the anode electrode 15 of the outer electron beam passing hole of the focus electrode 14 having different curvature radii are different from each other. Since the central axis (AC) of the outer electron beam through hole of the center is "D" eccentric, the distance from the openings 17 (19) of the focus electrode 14 and the anode electrode 15 to the electron beam is adjusted at an arbitrary angle. Could not adjust the focusing power.

Due to this rotationally asymmetrical focusing force, the outer electron beams 2a and 2c cause some distortion in the screen as shown in FIG. 5.

FIG. 5 illustrates the shape of an outer electron beam on a screen as a result of computer simulation of an electron gun to which an electrode forming the electrostatic focusing lens of FIG. 4 is applied.

As such, when the electron beam is deflected toward the periphery of the screen by the deflection yoke 6 in an unoptimized state at the center of the screen, the error component is enlarged and displayed, resulting in a decrease in resolution at the periphery of the screen.

The present invention has been made to solve such a problem in the prior art, the focusing force of the lens affecting the focusing of the outer electron beam in the main lens is almost independent of the direction (direction perpendicular to the tube axis) of the outer electron beam on the screen The goal is to improve the resolution across the entire screen by optimizing the shape.

According to an aspect of the present invention for achieving the above object, a three-pole portion consisting of a plurality of electron emitting means for emitting an electron beam, a plurality of electrodes for adjusting the radiation amount of the electron beam, and a main lens for focusing the electron beam on the screen In a cathode ray tube electron gun having a common passage opening of three electron beams formed on an opposing surface of the main lens forming electrode forming an inner portion, and an inner electrode is fixed at a point away from the opening, at least one of the focus electrode and the anode electrode. The shape of the outer electron beam through-hole of the opening formed in the electrode is formed from one axis perpendicular to the inline to the inside to be part of a circle, and the point where the axis and the electron beam through-hole meet, from the point where the outer shape of the outer electron beam through-hole meets the inline axis The curvature radius increases or decreases as it is formed. An electron gun for color cathode ray tubes is provided.

According to another aspect of the present invention, a main lens for forming a three-pole portion consisting of a plurality of electron emitting means for emitting an electron beam, a plurality of electrodes for adjusting the radiation amount of the electron beam, and a main lens for focusing the electron beam on the screen In a cathode ray tube electron gun in which three common electron beam openings are formed on opposite sides of the formation electrode, and inner electrodes are fixed at a predetermined distance from the opening, the openings formed in at least one of the focus electrode and the anode electrode. The radius of curvature increases from one axis perpendicular to the inline to the outside to be part of a circle, and goes from the point where the axis meets the electron beam through hole to the point where the outside electron beam through hole meets the central electron beam through hole. Color cathode ray tube, characterized in that formed to reduce Dragon guns are provided.

1 is a side view showing a part of a typical color cathode ray tube cut away

FIG. 2 is a longitudinal sectional view showing a structure of an inline electron gun applied to FIG. 1. FIG.

3 is an exploded perspective view showing a conventional focus electrode and an anode electrode

4 is a front view illustrating the electrodes of FIG. 3 overlapping each other;

5 is an electron beam formation formed on the screen by a conventional capacitive focusing lens

6 is a front view showing a first embodiment of the present invention.

7 is a front view showing a second embodiment of the present invention.

8 is a front view showing a third embodiment of the present invention.

9 is a front view showing a fourth embodiment of the present invention.

10 is an electron beam formation formed on the screen by the electrostatic focusing lens of the present invention

Explanation of symbols for main parts of the drawings

2a, 2c: outer electron beam 14: focus electrode

15: anode electrode 17, 19: opening

18, 20: inner electrode

Hereinafter, the present invention will be described in more detail with reference to FIGS. 6 to 10.

FIG. 6 is a front view showing a first embodiment of the present invention, and FIG. 7 is a front view showing a second embodiment of the present invention. The present invention provides an inner electrode 18 for lowering the resolution of the outer electron beams 2a and 2c. In order to solve the problem of rotational asymmetry focusing of the electrostatic lens formed due to misalignment between the center of the outer electron beam passing hole and the center of the outer electron beam 2a, 2c, and the rotational asymmetrical structure of the opening, the anode electrode 15 Or the focusing force in each direction is balanced with respect to the center of the outer electron beams 2a and 2c by improving the shape of the openings 17 and 19 of the focus electrode 14.

As in the first embodiment shown in FIG. 6, the opening 19 formed in the anode electrode 15 is shaped like a race track having a semicircle on the outside thereof. In this case, the outer electron beam in the focus side opening 17 is formed. The outer focusing force of (2a) and (2c) becomes stronger than the focusing force of the center electron beam 2b side.

Therefore, the focusing force of the outer side and the focusing force of the center electron beam 2b side are similar, that is, the outward divergence force of the outer electron beams 2a, 2c in the anode side opening 19 is equal to the divergence force of the center electron beam 2b side. The shape of the anode-side opening 19 is made into a chain link shape in which three circles are overlapped so as to be larger, and the shape of the outer electron beam passing part surrounding the outer electron beams 2a and 2c among the three overlapping circles. Is configured so that the center electron beam 2b side becomes a part of the circle and the outer side becomes a horizontal oblong shape ob <oa.

When the amount of eccentricity and position of the inner electrode is changed, the outer direction of the outer electron beams 2a and 2c is rather caused by the strong horizontal focus or weak horizontal divergence of one side by the focus side inner electrode 18 or the anode side inner electrode 20. As a result, weak divergence may be required.

To this end, the outer side of the outer electron beam passing portion of the anode-side opening portion 19, as shown in FIG.

Accordingly, the focusing force in each direction can be maintained almost evenly with respect to the center of the outer electron beams 2a and 2c, and the outer electron beams 2a and 2c can be uniformly focused in a circular or elliptical shape on the screen. This improves the resolution across the screen.

10 shows the shape of the outer electron beam on the screen of the computer simulation results of the electron gun having the shape as described above.

The outer electron beams 2a and 2c are formed close to the circle by the focusing force which is almost rotationally symmetrical at the center of the screen.

According to the present invention, the degree of focusing on the outer electron beams 2a and 2c is rotationally symmetrical, so that when the outer electron beams 2a and 2c are deflected to the periphery of the screen by the deflection yoke 6, the difference in the focusing forces It does not show the change of shape by.

As a result, small and distinct beam spots are formed throughout the screen, thereby improving resolution.

FIG. 8 shows a third embodiment in which the anode-side opening 19 is in the shape of a dog bone, the outer side of the outer electron beams 2a and 2c is part of an ellipse, and the inner side is a circle. Some are wrapped around.

This structure is also formed near the circle by the rotational symmetrical focusing force at the center of the screen as the outer electron beams 2a and 2c as shown in FIG. 10 as a result of the first and second embodiments described above.

The present invention provides a focus electrode 14 and an anode electrode 15 having an opening in the form of a race track and a chain link or a focus electrode 14 and an anode electrode 15 having an opening in the form of a race track and a dog bone. Although described as, it is not necessarily limited thereto.

That is, in the case where the electron beam through-holes, which are single openings, face each other, the curved portion of the inner side (center electron beam direction) is formed based on the center axis AC (FC) of the outer electron beam-passing portion. This is because it may be formed asymmetrically with the outer portion.

In particular, the radius of curvature of the outer electron beam passing portion is increased or decreased along the point where the outer shape of the outer electron beam passing portion meets the center axis of the electron beam passing portion, or the inner shape of the outer electron beam passing portion meets the central electron beam passing portion. The rotational symmetry focusing force of the outer electron beams 2a and 2c can be obtained by increasing or decreasing the radius of curvature that follows the point from the point to the point where the outer electron beam passing part meets the central axis.

In addition, it is understood that the present invention can be used as a means of balancing the horizontal and vertical focusing forces of the central electron beam 2b and the outer electron beams 2a and 2c, which are always felt in the design of the electron gun.

As described above, according to the present invention, the shape of the outer electron beam passing portion of the openings 17 and 19 which are formed to face the focus electrode 14 and the anode electrode 15, respectively, is appropriately changed, and thus the collection in each direction with respect to the outer electron beam is performed. By balancing the speed and sharpening the shape of the electron beam formed on the screen, it is possible to obtain a highly accurate electron gun corresponding to the high definition and wide angle of the cathode ray tube.

Claims (8)

Three electron beams on opposite sides of the main lens forming electrode forming a three-pole portion consisting of a plurality of electron radiating means for emitting an electron beam, a plurality of electrodes for adjusting the radiation amount of the electron beam, and a main lens for focusing the electron beam on the screen In a cathode ray tube electron gun in which inner common electrodes are formed and the inner electrodes are fixed at a point away from the opening, the outer electron beam through hole shape of the opening formed in at least one of the focus electrode and the anode electrode is inlined. The inner side is formed to be a part of a circle from a vertical axis, and the radius of curvature increases or decreases while the outer shape of the outer electron beam through hole meets the point where it meets the inline axis. Electron gun for colored cathode ray tubes. The method of claim 1, An electron gun for a color cathode ray tube, characterized in that the outer shape of the outer electron beam passing hole is formed as part of an ellipse of a horizontal or longitudinal shape. The method of claim 1, Electron gun for color cathode ray tube, characterized in that the opening of the focus electrode is formed in a race track shape. The method of claim 1, The electron gun for a color cathode ray tube, characterized in that the opening of the anode electrode is formed in the shape of a dog bone. Three electron beams on opposite sides of the main lens forming electrode forming a three-pole portion consisting of a plurality of electron radiating means for emitting an electron beam, a plurality of electrodes for adjusting the radiation amount of the electron beam, and a main lens for focusing the electron beam on the screen In a cathode ray tube electron gun in which inner common electrodes are formed at a predetermined distance from the openings, the inner electron beam through holes of the openings formed in at least one of the focus electrode and the anode electrode are inlined. The collar is formed to increase or decrease the radius of curvature from the one axis to the outside to form a portion of the circle, and from the point where the axis meets the electron beam passing hole to the point where the outer electron beam passing hole and the central electron beam passing hole meet. Electron gun for cathode ray tube. The method of claim 5, An electron gun for a color cathode ray tube, wherein the inner shape of the outer electron beam passing hole is formed as a part of an ellipse of a horizontal or longitudinal shape. The method of claim 5, Electron gun for color cathode ray tube, characterized in that the opening of the focus electrode is formed in a race track shape. The method of claim 5, The electron gun for a color cathode ray tube, characterized in that the opening of the anode electrode is formed in the shape of a dog bone.