JP2000030628A - Electron gun assembly for cathode ray tube - Google Patents

Abstract

(57) Abstract: Provided is an electron gun assembly for a cathode ray tube which can realize good resolution over the entire screen with a relatively simple configuration without increasing a parabolic voltage component applied to a focusing electrode. The purpose is to: In an electron gun assembly, a focusing electrode G5 constituting a main lens portion, intermediate electrodes Gm1 and Gm2 disposed adjacent to the focusing electrode, and a final accelerating electrode G6 disposed adjacent to the intermediate electrode are provided. , Arranged in a row in the horizontal direction
Three openings are respectively formed in the horizontal direction corresponding to the respective cathodes KB, KG, and KR.
A pair of convex portions 31 extending in the horizontal direction are provided on the surface facing the intermediate electrode side of the focusing electrode so as to sandwich the three apertures of the focusing electrode from the vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun assembly for a cathode ray tube, and more particularly to an electron gun assembly applied to a cathode ray tube such as a color cathode ray tube.

[0002]

2. Description of the Related Art In general, a color cathode ray tube, which is a typical example of a cathode ray tube, generates three electron beams emitted from an electron gun structure by a horizontal deflection coil and a vertical deflection coil of a deflection yoke mounted outside an envelope. Deflected by the deflection magnetic field,
The three electron beams are selected by a shadow mask, and are scanned on a phosphor screen in a horizontal direction and a vertical direction to display a color image.

[0003] Such a color cathode ray tube is provided with an in-line type electron gun which emits three electron beams arranged in a line composed of a center beam and a pair of side beams passing on the same horizontal plane. The deflection yoke generates an asymmetric magnetic field by combining a pincushion-type deflection magnetic field generated by a horizontal deflection coil and a barrel-type deflection magnetic field generated by a vertical deflection coil.

As described above, a so-called self-convergence type in-line type color cathode-ray tube, in which three electron beams emitted from an in-line type electron gun assembly are self-concentrated by an asymmetric magnetic field generated by a deflection yoke, is widely used. ing.

However, the electron beam of the color cathode ray tube suffers from a deflection distortion due to an increase in the deflection angle, and there is a disadvantage that the resolution at the periphery of the screen is deteriorated. That is, as shown in FIG. 1, even if the beam spot 4a at the center of the screen is substantially a perfect circle, the beam spot 4b at the periphery of the screen is
In addition to the elliptical high-luminance core portion 5 extending in the horizontal direction, the shape has a low-luminance halo portion 6 extending in the vertical direction. The distortion of the beam spot in the peripheral portion of the screen is caused by an increase in the vertical focusing force due to the non-uniformity of the deflection magnetic field.

According to Japanese Patent Application Laid-Open No. 64-38947, in order to improve the resolution degradation caused by the deflection distortion, the electron gun assemblies are arranged in a line in the horizontal direction as shown in FIGS. An electron beam generator configured by three arranged cathodes KR, KG, KB, a first electrode G1, a second electrode G2, and a third electrode G3; a third electrode G3, a fourth electrode G4, and an It includes an auxiliary lens unit constituted by five electrodes G5, and a main lens unit constituted by a fifth electrode G5, a first intermediate electrode Gm1, a second intermediate electrode Gm2, and a sixth electrode G6. The fifth electrode G5 functions as a focusing electrode, and the sixth electrode G6 functions as a final acceleration electrode. The electron gun assembly further includes a resistor 32 disposed along the electrode, and divides the high voltage supplied to the final accelerating electrode G6 by the resistor 32, thereby dividing the first and second intermediate electrodes Gm1 and Gm1. A predetermined voltage is supplied to Gm2.

In this manner, the focusing electrode G5, the first and second intermediate electrodes Gm1 and Gm2 constituting the main lens portion,
In addition, the voltage of the final acceleration electrode G6 is configured to gradually increase from the electron beam generation unit side toward the phosphor screen. The focusing electrode G5 is supplied with a focusing voltage in which a parabolic voltage that changes in synchronization with the deflection of the electron beam is superimposed on a constant DC voltage.

In the main lens portion of the electron gun assembly, a focusing electrode G5 and a first intermediate electrode Gm adjacent to the focusing electrode G5 are provided.
Due to the voltage difference formed between them, an asymmetric focusing electric field having an action of strongly focusing the electron beam relatively vertically is formed. In addition, the voltage difference between the second intermediate electrode Gm2 and the final accelerating electrode G6 adjacent to the second intermediate electrode Gm2 causes an asymmetric divergence having the effect of strongly diverging the electron beam relatively vertically. An electric field is formed.

Therefore, at the center of the screen, the asymmetric focusing electric field at the front stage and the asymmetric diverging electric field at the rear stage are balanced, and a substantially perfect beam spot is obtained. On the other hand, in the peripheral portion of the screen, the focusing voltage increases with an increase in the deflection angle of the electron beam, the voltage difference between the focusing electrode G5 and the first intermediate electrode Gm1 decreases, and the relative voltage in the asymmetric focusing electric field in the preceding stage increases. As a result, the focusing action in the vertical direction is weakened, and the electron beam is diverged mainly in the vertical direction, thereby canceling the deflection distortion that is strongly focused in the vertical direction and is received by the non-uniform magnetic field of the deflection yoke.

By the way, between the focusing electrode G5 and the first intermediate electrode Gm1, between the first intermediate electrode Gm1 and the second intermediate electrode Gm2, and between the second intermediate electrode Gm2 and the final acceleration electrode G6. Has a capacitance. Therefore, of the focusing voltage applied to the focusing electrode G5, the parabolic voltage component is converted into the first and second intermediate electrodes Gm via the capacitance.
1 and Gm2.

When the electron beam is deflected to the peripheral portion of the screen, the first and second intermediate electrodes Gm1 are deflected by this capacitance.
And the parabolic voltage component induced in Gm2
Assuming that the capacitance existing between the electrodes is substantially the same, the voltage component induced at the first intermediate electrode Gm1 is about ２ of the parabolic voltage component superimposed on the focusing electrode G5, The voltage component induced at the second intermediate electrode Gm2 is about 1/3 of the parabolic voltage component superimposed on the focusing electrode G5.

Therefore, the first and second intermediate electrodes Gm1 and Gm1 are induced by the induction of such a parabolic voltage component.
The voltage of m2 changes in synchronization with the deflection of the electron beam. For this reason, the parabolic voltage component does not effectively act on the deflection distortion correction, so that sufficient correction cannot be performed. In addition, when the electron beam is deflected to the peripheral portion of the screen, if the parabolic voltage component is increased to correct the deflection distortion, a load is applied to the voltage power supply that supplies the parabolic voltage component. However, since the voltage change is large, the withstand voltage characteristic is deteriorated.

In order to eliminate the spot distortion at the center of the screen due to the induction of such a parabolic voltage component, according to Japanese Patent Laid-Open No. 4-147545, the electron gun assembly is shown in FIGS. As shown, a voltage difference between the focusing electrode G5 and the first intermediate electrode Gm1 adjacent to the focusing electrode G5 forms an asymmetric focusing electric field having an action of strongly focusing the electron beam relatively vertically. The voltage difference between the second intermediate electrode Gm2 and the final accelerating electrode G6 adjacent to the second intermediate electrode Gm2 forms an asymmetric diverging electric field having an action of relatively diverging the electron beam in the vertical direction. . Further, as shown in FIG. 6, the first intermediate electrode Gm1 in the electron gun assembly extends in the horizontal direction arranged so as to sandwich three apertures on the surface facing the second intermediate electrode Gm2. It has a pair of convex portions. Then, an asymmetric focusing electric field is formed between the first and second intermediate electrodes Gm1 and Gm2 to strongly focus the electron beam relatively vertically.

In this electron gun assembly, the parabolic voltage component superimposed on the focusing electrode G5 has the first and second intermediate electrodes G
In the state guided to m1 and Gm2, at the center of the screen,
The asymmetric focusing electric field formed between the focusing electrode G5 and the first intermediate electrode Gm1 and strongly focused in the relatively vertical direction is weakened, and is formed between the second intermediate electrode Gm2 and the final acceleration electrode G6. Although the asymmetric diverging electric field which diverges relatively strongly in the vertical direction becomes strong, at the same time, the first and second intermediate electrodes G
The relatively strongly focused asymmetric focusing field formed between m1 and Gm2 also becomes stronger. As a result, in the center of the screen, even if there is a parabola-like voltage component induction, the two asymmetric focusing electric field and the asymmetric diverging electric field are balanced,
Spot distortion will be suppressed.

However, in such a configuration, since the facing area between the first and second intermediate electrodes Gm1 and Gm2 is reduced, when a parabolic voltage component is applied to the focusing electrode G5, it is adjacent to the focusing electrode G5. Induction to the first intermediate electrode Gm1 increases.

Therefore, when correcting the deflection distortion at the peripheral portion of the screen, the potential difference between the focusing electrode G5 and the first intermediate electrode Gm1 is further increased as compared with the conventional electron gun assembly, and sufficient deflection is achieved. The distortion cannot be corrected.
Further, between the first and second intermediate electrodes Gm1 and Gm2,
Although the effective aperture is enlarged by reducing the potential gradient, in such a configuration, the first and second intermediate electrodes G
Since an asymmetric focusing electric field is formed between m1 and Gm2, the effective aperture, particularly in the vertical direction, is reduced, and the spot diameter is deteriorated.

Further, as a configuration for resolving the deficiency of the deflection distortion correction, in order to strengthen the effect of the asymmetric electric field, the vertical diameter of the aperture of the focusing electrode G5 and the final acceleration electrode G6 is relatively set as compared with the horizontal diameter. There are ways to make it smaller. However, in this method, the electron beam passing in the vertical direction of the opening relatively passes near the opening. That is, the light passes through the outside of the formed electric field lens, and the aberration of the electric field lens increases, thereby deteriorating the vertical diameter of the electron beam spot. In particular, on the focusing electrode G5 side, the final acceleration electrode G6
Since the cross-sectional area of the passing electron beam is larger than that of the side,
Reduction of the vertical diameter of the aperture of the focusing electrode deteriorates the electron beam spot diameter.

[0018]

In a self-convergence type in-line type color CRT, a deflection yoke is used because a combination of an electron gun assembly for emitting electron beams arranged in a row and a deflection yoke for generating an asymmetric magnetic field is used. Due to the non-uniform magnetic field, the cross-sectional shape of the electron beam is distorted with an increase in the deflection angle, and there is a disadvantage that the resolution particularly at the periphery of the screen is deteriorated.

In order to improve the degradation of resolution due to the deflection distortion, a main lens section in which a focusing electrode, two intermediate electrodes, and a final accelerating electrode are sequentially arranged from the electron beam generating section toward the phosphor screen is provided. There is an electron gun assembly provided with a resistor that divides a voltage supplied to a final acceleration electrode and supplies a predetermined voltage to each intermediate electrode. In this electron gun assembly, a voltage component that changes in a parabolic manner with an increase in the deflection angle of an electron beam is supplied to a focusing electrode with a focusing voltage superimposed on a constant DC voltage, and the focusing electrode and the focusing electrode are adjacent to the focusing electrode. The intermediate electrode forms an asymmetric focusing electric field that strongly focuses the electron beam relatively vertically, and the final acceleration electrode and the intermediate electrode adjacent to the final acceleration electrode form:
An asymmetric diverging electric field that diverges the electron beam strongly in the vertical direction is formed.

In such an electron gun assembly, for the electron beam landing at the center of the screen, the action of the asymmetric focusing electric field at the front stage and the action of the asymmetric diverging electric field at the rear stage are balanced, and the center of the screen is balanced. It is configured so that a substantially perfect beam spot can be obtained at the portion. Further, in such an electron gun assembly, the action of the asymmetric focusing electric field in the former stage is weakened for the electron beam landing on the periphery of the screen due to the deflection of the deflection yoke, and the asymmetric diverging electric field in the latter stage is relatively reduced. By strengthening the function and diverging the electron beam mainly in the vertical direction, it is configured so as to cancel the deflection distortion that is strongly focused in the vertical direction, which is received from the asymmetric magnetic field of the deflection yoke.

However, in this electron gun assembly, due to the capacitance existing between the electrodes, a parabolic voltage component of the focusing voltage applied to the focusing electrode is applied to the intermediate electrode via the capacitance. Therefore, there is a problem that the deflection distortion cannot be sufficiently corrected and the resolution cannot be sufficiently improved in the peripheral portion of the screen. Also, in the periphery of the screen,
If the parabolic voltage component is increased in order to enhance the effect of the deflection distortion correction, the voltage change increases, and the withstand voltage characteristics deteriorate.

Therefore, an electron gun assembly that eliminates spot distortion at the center of the screen due to the induction of a parabolic voltage component, the electron beam is relatively controlled by a focusing electrode and a first intermediate electrode adjacent to the focusing electrode. Forming an asymmetric focusing electric field having a function of strongly focusing in the vertical direction, and by the final acceleration electrode and the second intermediate electrode adjacent to the final acceleration electrode,
Creates an asymmetric diverging electric field that has the effect of diverging the electron beam in the vertical direction relatively strongly, and forms an asymmetric focusing electric field that focuses the electron beam in the vertical direction relatively between the two intermediate electrodes. I do.

With such a configuration, in the state where the parabolic voltage component superimposed on the focusing electrode is guided to the two intermediate electrodes, the central portion of the screen is located between the focusing electrode and the first intermediate electrode. The asymmetric focusing electric field which is relatively strongly focused in the vertical direction is weakened, and the asymmetrically divergent electric field which is relatively strongly diverged in the vertical direction between the second intermediate electrode and the final accelerating electrode is strong. The asymmetric focusing electric field that is relatively strongly focused between the intermediate electrodes is strengthened so as to suppress the distortion of the spot.

However, in this electron gun assembly, since the facing area between the two intermediate electrodes is reduced, when a parabolic voltage component is applied to the focusing electrode, the voltage is guided to the first intermediate electrode adjacent to the focusing electrode. Will increase.

Therefore, when correcting the deflection distortion at the peripheral portion of the screen, the voltage difference between the focusing electrode and the first intermediate electrode becomes
The size remains larger than that of the conventional electron gun structure, and sufficient correction cannot be performed. In addition, the effective aperture is enlarged by reducing the potential gradient between the two intermediate electrodes, but in the above-described means, since an asymmetric focusing electric field is formed between the two intermediate electrodes, The effective aperture in the vertical direction is reduced, and the electron beam spot diameter is deteriorated.

In order to reduce the parabolic voltage component, the vertical diameter of the aperture of the focusing electrode and the final accelerating electrode is set to be horizontal in order to enhance the effects of the asymmetric focusing electric field at the front stage and the asymmetric diverging electric field at the rear stage. There is a method of reducing the size compared to the diameter. However, since the vertical diameter of the aperture is reduced, the aberration that the electron beam receives from the electric field lens increases, thereby deteriorating the vertical diameter of the beam spot.

The present invention has been made in order to solve the above-mentioned problems, and has a relatively simple structure without increasing the parabolic voltage component applied to the focusing electrode, and providing a satisfactory image over the entire screen. It is an object of the present invention to provide a cathode ray tube electron gun assembly capable of realizing resolution.

[0028]

According to the first aspect of the present invention, there are provided three cathodes arranged in a line on a same horizontal plane in a horizontal direction. A focusing electrode provided with three apertures formed in parallel in the horizontal direction corresponding to the electron beams emitted from the cathodes, to which a first level voltage is supplied; And an aperture formed corresponding to each electron beam passing through the aperture of the focusing electrode, and a second level voltage higher than the first level is supplied. At least one intermediate electrode and an aperture disposed adjacent to the intermediate electrode and having an aperture formed corresponding to each electron beam that has passed through the aperture of the intermediate electrode. A final accelerating electrode supplied with a third level voltage higher than two levels , A resistor supplied to the intermediate electrode by dividing a voltage supplied to the final accelerating electrode to a predetermined value,
Forming an asymmetric focusing electric field having an action of strongly focusing each electron beam relatively vertically in a direction between the focusing electrode and the intermediate electrode, between the intermediate electrode and the final accelerating electrode. An electron gun for a cathode ray tube which forms an asymmetric diverging electric field having an action of strongly diverging an electron beam relatively vertically and changes a voltage supplied to the focusing electrode in synchronization with the deflection of the electron beam. In the structure,
The surface of the focusing electrode facing the intermediate electrode is
An electron gun assembly for a cathode ray tube, comprising a pair of projections extending in the horizontal direction that is the same as the arrangement direction of the three openings so as to sandwich the openings from the vertical direction. Is provided.

According to the second aspect of the present invention, three cathodes arranged in a row in the horizontal direction on the same horizontal plane, and the aperture formed corresponding to each electron beam emitted from each of the cathodes A focusing electrode to which a first level voltage is supplied, and a focusing electrode arranged adjacent to the focusing electrode;
It has three apertures formed in parallel in the horizontal direction corresponding to each electron beam passing through the aperture of the focusing electrode,
At least one intermediate electrode to which a second level voltage higher than the first level is supplied, and at least one intermediate electrode that is disposed adjacent to the intermediate electrode and passes through the opening of the intermediate electrode. Having a correspondingly formed aperture,
A final acceleration electrode to which a third level voltage higher than the second level is supplied; and a resistor which divides a voltage supplied to the final acceleration electrode into a predetermined value and supplies the voltage to the intermediate electrode. An asymmetric focusing electric field having an action of strongly focusing each electron beam relatively vertically in an electrode is formed between the electrode and the intermediate electrode, and an electron beam is formed between the intermediate electrode and the final acceleration electrode. In an electron gun assembly for a cathode ray tube, which forms an asymmetric diverging electric field having an action of diverging strongly in the vertical direction and changes a voltage supplied to the focusing electrode in synchronization with the deflection of an electron beam. An electron gun assembly for a cathode ray tube, characterized in that a convex portion extending in the vertical direction is provided on the surface facing the focusing electrode side of the electrode so as to sandwich the three openings of the intermediate electrode from the horizontal direction. Provided .

According to the third aspect of the present invention, the three cathodes arranged in a line in the horizontal direction on the same horizontal plane and the electron beams emitted from the respective cathodes are arranged in parallel in the horizontal direction. A focusing electrode to which a first-level voltage is supplied, and which is disposed adjacent to the focusing electrode and has passed through the opening of the focusing electrode. It has three openings formed in parallel in the horizontal direction corresponding to each electron beam, and a second opening higher than the first level.
At least one intermediate electrode to which a voltage of a level is supplied, and disposed adjacent to the intermediate electrode;
A final acceleration electrode having an aperture formed corresponding to each electron beam passing through the aperture of the intermediate electrode, to which a third level voltage higher than the second level is supplied; A resistor that divides a voltage supplied to the electrode into a predetermined value and supplies the voltage to the intermediate electrode, and between the focusing electrode and the intermediate electrode, strongly focuses each electron beam relatively vertically. Forming an asymmetric focusing electric field having an effect, and forming an asymmetric diverging electric field having an action of strongly diverging an electron beam relatively vertically in the intermediate electrode and the final accelerating electrode; and In a cathode ray tube electron gun assembly for changing a voltage supplied to a focusing electrode in synchronization with the deflection of an electron beam, three apertures of the focusing electrode are vertically formed on a surface facing the intermediate electrode side of the focusing electrode. Horizontal direction to pinch A pair of extending protrusions is provided, and a protrusion extending in a vertical direction is provided on a surface facing the focusing electrode side of the intermediate electrode so as to sandwich three openings of the intermediate electrode from a horizontal direction. An electron gun structure for a cathode ray tube is provided.

According to the fourth aspect of the present invention, the three cathodes arranged in a row in the horizontal direction on the same horizontal plane, and the cathodes are arranged in parallel in the horizontal direction corresponding to the electron beams emitted from the respective cathodes. A focusing electrode to which a first-level voltage is supplied, and which is disposed adjacent to the focusing electrode and has passed through the opening of the focusing electrode. It has an opening formed corresponding to each electron beam,
At least one intermediate electrode to which a second level voltage higher than the first level is supplied, and at least one intermediate electrode that is disposed adjacent to the intermediate electrode and passes through the opening of the intermediate electrode. Having a correspondingly formed aperture,
A final acceleration electrode to which a third level voltage higher than the second level is supplied; and a resistor which divides a voltage supplied to the final acceleration electrode into a predetermined value and supplies the voltage to the intermediate electrode. An asymmetric focusing electric field having an action of strongly focusing each electron beam relatively vertically in an electrode is formed between the electrode and the intermediate electrode, and an electron beam is formed between the intermediate electrode and the final acceleration electrode. An electron gun assembly for a cathode ray tube which forms an asymmetric diverging electric field having an action of diverging strongly in a vertical direction and changes a voltage supplied to the focusing electrode in synchronization with the deflection of an electron beam. An electron gun assembly for a cathode ray tube, wherein a cylindrical electrode common to the three apertures of the focusing electrode and having a long side in the horizontal direction is provided on a surface facing the intermediate electrode side of the electrode. Is done.

According to the electron gun assembly for a cathode ray tube of the present invention, the focusing electrode is provided on the surface facing the intermediate electrode side.
A pair of protrusions extending in the horizontal direction may be provided so as to sandwich the opening portions from the vertical direction, or three opening portions of the intermediate electrode may be provided on the intermediate electrode and on the opposing surface on the focusing electrode side. A tube having a convex portion extending in the vertical direction so as to be sandwiched from the horizontal direction, or a tube having a long side in the horizontal direction common to the three apertures of the focusing electrode on the surface facing the intermediate electrode on the focusing electrode. It is configured by providing a shaped electrode or by combining these configurations.

For this reason, when a focused voltage in which a constant DC voltage is superimposed on a parabolic voltage component is supplied to the focusing electrode, the area of opposition between the focusing electrode and the intermediate electrode adjacent to the focusing electrode is reduced by the projection. In addition, the capacitance existing between the electrodes decreases. Therefore, it is possible to prevent the parabolic voltage component from being induced to the intermediate electrode via the capacitance, and it is possible to maintain the voltage of each electrode at a predetermined value.

In addition, an asymmetric focusing electric field stronger than before can be formed between the focusing electrode and the intermediate electrode adjacent to the focusing electrode. Can be improved without increasing the voltage component of

Furthermore, by providing the convex portion, the relative diameter between the focusing electrode and the intermediate electrode adjacent to the focusing electrode can be reduced without making the vertical diameter of the opening of the focusing electrode smaller than the horizontal diameter. Since an asymmetric focusing electric field having a strong focusing action in the vertical direction can be formed, aberration components in the vertical direction of the electric field lens can be suppressed. Therefore, a good beam spot can be obtained, and a good resolution can be obtained over the entire screen.

[0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of an electron gun assembly for a cathode ray tube according to the present invention. Here, a QPF (Quadra Potential Focus) type electron gun structure will be described as an example of an electron gun structure applied to a cathode ray tube.

FIG. 6 is a plan view schematically showing a structure of a self-convergence type in-line type color cathode ray tube as an example of a cathode ray tube to which the electron gun assembly of the present invention is applied. That is, this color cathode ray tube has an envelope composed of a funnel 21 integrally joined to the panel 20. On the inner surface of this panel 20, blue,
A phosphor screen 22 having phosphor layers of three colors that emit green and red light is provided. At a position facing the phosphor screen 22, a shadow mask 23 having a large number of electron beam passage holes is provided. An electron gun assembly 26 that emits three electron beams 25B, 25G, and 25R in the tube axis direction, that is, the Z-axis direction, is provided in the neck 24 of the funnel 21. The electron beam emitted from the electron gun assembly 26 is composed of a center beam 25G and a pair of side beams 25B and 25R arranged in a line in the horizontal direction on the same horizontal plane, that is, in the H-axis direction. An anode terminal 27 is provided on the funnel 21, and an inner conductive film 2 is provided on the inner surface of the funnel 21.
8 are formed.

Outside the funnel 21, the electron gun assembly 2
3 electron beams 25B, 25G, 25R emitted from 6
A deflection yoke 29 having a horizontal deflection coil for generating a pincushion-type deflection magnetic field and a vertical deflection coil for generating a barrel-type deflection magnetic field is provided to form a non-uniform magnetic field for deflecting the light. .

In this color cathode ray tube, the three electron beams 25B, 25B emitted from the electron gun assembly 26 are used.
G, 25R are deflected while being self-concentrated, that is, self-converged, on the phosphor screen 22 by the non-uniform magnetic field generated by the deflection yoke 29.
2 is configured to display a color image on the phosphor screen 22 by scanning horizontally and vertically.

FIG. 8 is a horizontal sectional view schematically showing the structure of an electron gun assembly applied to the color CRT according to the present embodiment. FIG. 9 is a vertical sectional view schematically showing the structure of the electron gun structure shown in FIG.

As shown in FIGS. 8 and 9, the electron gun assembly 2
Reference numeral 6 denotes 3 arranged in a row in the horizontal direction, that is, in the H-axis direction.
Cathodes KB, KG, KR, each of these cathodes KB, K
Three heaters (not shown) inserted inside G and KR, a first electrode G1, a second electrode G2, a third electrode G3, and a first electrode G1, which are sequentially arranged along the Z-axis direction from the cathode side toward the phosphor screen. It has a fourth electrode G4, a fifth electrode G5, ie, a focusing electrode, a first intermediate electrode Gm1, a second intermediate electrode Gm2, a sixth electrode G6, ie, a final acceleration electrode, and a shield cup SC attached to the sixth electrode G6. Among these components, the heater excluding the shield cup SC,
Cathodes KB, KG, KR, first to sixth electrodes G1 to G
6, and the first and second intermediate electrodes Gm1 and Gm2 are vertically connected to each other by a pair of insulating supports (not shown).
It is integrally fixed by being clamped in the axial direction.

Each of the first electrode G1 and the second electrode G2 is formed by a plate-like electrode having a relatively small thickness and having an integral structure. On the plate surface of this plate-shaped electrode, the cathodes K arranged in a row are arranged.
Three relatively small circular openings arranged in the horizontal direction corresponding to B, KG, and KR are formed.

The third electrode G3, the fourth electrode G4, the fifth
The electrode G5 and the sixth electrode G6 are each formed by a cylindrical electrode having an integral structure formed by attaching a cup-shaped electrode.

On the bottom surface of the cup-shaped electrode located on the second electrode G2 side of the third electrode G3, the cathodes KB, KG,
Three circular openings arranged in the horizontal direction corresponding to KR are formed. These three circular apertures are used for the second electrode G2.
Has a larger opening diameter than the opening formed in the hole.

Further, a cup-shaped electrode located on the fourth electrode G4 side of the third electrode G3, a pair of cup-shaped electrodes forming the fourth electrode G4, two pairs of cup-shaped electrodes forming the fifth electrode G5, and On each bottom surface of the cup-shaped electrode located on the shield cup SC side of the sixth electrode G6, the cathodes KB, K
Three circular openings arranged in the horizontal direction corresponding to G and KR are formed. These three circular apertures are the third
It has a larger opening diameter than the circular opening formed on the second electrode G2 side of the electrode G3.

Further, the second intermediate electrode Gm of the sixth electrode G6
On the bottom surface of the cup-shaped electrode located on the second side, 3 are arranged in a horizontal direction corresponding to the cathodes KB, KG, and KR arranged in a line.
Individual apertures are formed. The three openings have a larger opening diameter than the circular opening formed on the second electrode G2 side of the third electrode G3, and are formed in a circular or non-circular shape.

The first intermediate electrode Gm1 and the second intermediate electrode Gm2 located between the fifth electrode G5 and the sixth electrode G6 are each formed of a plate-like electrode having a relatively large plate thickness and an integral structure. On the plate surface of the plate-like electrode, three electrodes 3 arranged in a horizontal direction corresponding to the cathodes KB, KG, and KR arranged in a line.
A plurality of circular apertures are formed. These three circular apertures have substantially the same diameter as the circular aperture of the fifth electrode G5.

As shown in FIG. 9, a resistor 32 is arranged on the electron gun assembly 26 along a plurality of electrodes integrally fixed by a pair of insulating supports. The resistor 32 has one end connected to the sixth electrode G6 and the other end hermetically penetrating a stem (not shown) sealing a stem (not shown) sealing the neck end of the color cathode-ray tube. , Or grounded via a variable resistor 35 outside the tube. The resistor 32 is connected to the first intermediate electrode Gm1 at the other end of the intermediate portion, and at one end of the intermediate portion,
It is connected to the second intermediate electrode Gm2.

The anode terminal 27, the inner conductive film 28, and the shield cup SC provided on the funnel are attached to the anode conductive film 28 via a plurality of valve spacers (not shown) and the shield cup SC which are pressed against the inner conductive film 28. , The anode high voltage supplied to the sixth electrode G6 is divided,
A predetermined voltage is applied to the first intermediate electrode Gm1 and the second intermediate electrode Gm
2 respectively.

A first intermediate electrode Gm to which an anode high voltage is applied from an anode terminal 27 is applied to each electrode of the electron gun assembly 26.
Except for the first and second intermediate electrodes Gm2, a predetermined voltage is supplied via a stem pin that penetrates the stem airtightly. That is, the cathodes KB, KG, and KR have, for example, about 190
A voltage in which the image signal is superimposed on the V DC voltage is applied. Further, the first electrode G1 is grounded. The second electrode G2 and the fourth electrode G4 are connected in a tube to about 800
V DC voltage is applied. A focusing voltage is applied to the third electrode G3 and the fifth electrode G5, which is connected in a tube and superimposed on a DC voltage of about 8 to 9 kV and a voltage that changes in a parabolic manner in synchronization with the deflection of the electron beam.

An anode high voltage of about 30 kV is applied to the sixth voltage G 6 from the anode terminal 27. A voltage of about 40% of the anode high voltage is applied to the first intermediate electrode Gm1 via the resistor 32, and a voltage of about 65% of the anode high voltage is also applied to the second intermediate electrode Gm2. It is applied via the device 32.

By applying the above-described voltages to the respective electrodes of the electron gun assembly 26, the electrons emitted from the cathodes KB, KG, and KR are applied to the first electrode G1.
When passing through three circular apertures of the second electrode G2 and the second electrode G2, respectively, a crossover is formed in the vicinity of the first electrode G1 and the second electrode G2 and then diverged, and the second electrode G2 and the third electrode G3 respectively. When passing through the three circular apertures, prefocusing is performed by a prefocus lens formed by the second electrode G2 and the third electrode G3.

That is, the cathodes KB, KG, and KR and the first to third electrodes G1 to G3 form the cathodes KB, KG, and KR.
An electron beam generator is configured to control the emission of electrons from the electron beam and to focus the emitted electrons to form an electron beam.

When the three electron beams formed by the electron beam generator pass through the three circular apertures of the third electrode G3, the fourth electrode G4, and the fifth electrode G5, that is, the focusing electrodes, the three electron beams are generated. Preliminary focusing is performed by an auxiliary lens formed by the third electrode G3 to the fifth electrode G5.

The three electron beams pre-focused by the auxiliary lens are further supplied to a fifth electrode G5, a first intermediate electrode Gm1, a second intermediate electrode Gm2, and a sixth electrode G6.
That is, when passing through the three circular apertures of the final acceleration electrodes, the light is finally focused by the main lens portion formed by these electrodes and reaches the phosphor screen 22.

Of the operations of the electron gun assembly 26 having such a configuration, the operation of the main lens portion thereof will be described in more detail. That is, the main lens unit of the conventional electron gun structure is the fifth lens unit.
In the vicinity of the electrode G5 and the first intermediate electrode Gm1 adjacent to the electrode G5, an asymmetrical focusing electric field for strongly focusing the electron beam relatively vertically is formed, and the second intermediate electrode Gm2 and the sixth electrode G6 adjacent thereto are formed. , An asymmetrically diverging electric field is formed in which the electron beam is strongly diverged relatively vertically.

In the conventional electron gun structure having such a configuration, when a parabolic voltage component is superimposed on the fifth electrode G5 in order to correct the deflection distortion at the peripheral portion of the screen, the parabolic voltage component is changed to the second voltage. First intermediate electrode Gm1 and second intermediate electrode G
m2. As an example, assuming that a parabolic voltage component is applied at 1 kV in the periphery of the screen, a voltage of about 660 V is superimposed on the first intermediate electrode Gm1, and a voltage of about 330 V is superimposed on the second intermediate electrode Gm2. Due to the superposition of such voltages, the action of the asymmetric focusing electric field in the former stage becomes stronger than the predetermined action, and the action of the asymmetric diverging electric field in the subsequent stage becomes weaker than the predetermined action, so that the correction of the deflection distortion becomes insufficient. However, the resolution at the periphery of the screen cannot be sufficiently obtained.

On the other hand, in the electron gun assembly 26 according to this embodiment, the first intermediate electrode G5 of the fifth electrode G5
As shown in FIGS. 9 and 10, a pair of convex portions 31 extending in the horizontal direction, that is, in the H-axis direction are provided on the bottom surface of the cup-shaped electrode located on the m1 side. The pair of projections 31 are provided so as to sandwich the opening 30 formed on the bottom surface of the cup-shaped electrode located on the first intermediate electrode Gm1 side in the vertical direction, that is, the V-axis direction.

As shown in FIGS. 8 and 11, a plurality of convex portions 42 extending in the vertical direction, that is, in the V-axis direction, are provided on the surface of the first intermediate electrode Gm1 facing the focusing electrode G5. Is provided. The plurality of convex portions 42
The aperture 41 is provided so as to sandwich the opening 41 on the facing surface on the focusing electrode G5 side from the horizontal direction, that is, the H-axis direction side. That is,
Four convex portions 42 are provided so as to sandwich the three opening portions 41 from the horizontal direction side.

As described above, the convex area 31 provided on the fifth electrode G5 and the convex area 42 provided on the first intermediate electrode Gm1 reduce the facing area between the fifth electrode G5 and the first intermediate electrode Gm1. This is reduced to about 1/10, and the capacitance between these electrodes is greatly reduced. For this reason, when a parabolic voltage component that changes in synchronization with the deflection of the electron beam is supplied to the fifth electrode G5, the first intermediate electrode Gm1 and the second intermediate electrode Gm
2 can be suppressed.

The fifth electrode G5 and the first intermediate electrode Gm1
A stronger asymmetric focusing electric field can be formed between the above and the conventional electron gun assembly. Therefore, the parabolic voltage component for correcting the deflection distortion is more than the conventional electron gun structure.
More effective action can be obtained, and good resolution can be obtained without increasing the parabolic voltage component at the periphery of the screen.

In this embodiment, the fifth electrode G5
By providing a pair of protrusions 31 extending in the horizontal direction with the opening 30 formed therebetween, the vertical diameter of the opening 30 of the fifth electrode G5 can be increased. The vertical diameter of the electric field lens can be increased, and the aberration that the electron beam receives from the electric field lens formed between the plurality of electrodes, particularly the vertical aberration, can be reduced. Therefore, the vertical diameter of the beam spot can be reduced, and good resolution can be obtained over the entire screen.

Next, an electron gun structure according to another embodiment of the present invention will be described. In the other embodiments, for the same components as those in the above-described embodiment,
The same reference numerals are given and the detailed description is omitted.

That is, similarly to the above-described embodiment, the electron gun assembly according to the other embodiment has three cathodes KB, KG, KR arranged in a line in the horizontal direction and sequentially along the tube axis direction. The arranged first electrode G1, second electrode G2, third electrode G3, fourth electrode G4, fifth electrode G5, first intermediate electrode Gm1, second intermediate electrode Gm2, sixth electrode G6, and shield cup SC Have. The cathode and the plurality of electrodes are integrally fixed by being sandwiched between a pair of insulating indicators.

Each of the plurality of electrodes has 3 electrodes.
Three circular openings arranged in the horizontal direction corresponding to the three cathodes are formed. Further, a predetermined voltage is supplied to each electrode of the electron gun assembly 26. That is, the cathode K
For example, a voltage in which an image signal is superimposed on a DC voltage of about 190 V is applied to B, KG, and KR. Further, the first electrode G1 is grounded. A DC voltage of about 800 V is applied to the second electrode G2 and the fourth electrode G4 in a tube. A focusing voltage is applied to the third electrode G3 and the fifth electrode G5, which is connected in a tube and superimposed on a DC voltage of about 8 to 9 kV and a voltage that changes in a parabolic manner in synchronization with the deflection of the electron beam. An anode high voltage of about 30 kV is applied from the anode terminal 27 to the sixth voltage G6. Also, the first
A voltage of about 40% of the anode high voltage is applied to the intermediate electrode Gm1 via the resistor 32, and a voltage of about 65% of the anode high voltage is also applied to the second intermediate electrode Gm2 via the resistor 32. Applied.

Thus, the cathodes KB, KG, KR,
An electron beam generator is formed by the first to third electrodes G1 to G3, an auxiliary lens is formed by the third to fifth electrodes, and a fifth electrode G5, first and second intermediate electrodes Gm1 and Gm2, And the sixth electrode G6 forms a main lens portion.

In the embodiment described with reference to FIGS. 8 to 11, the cup-shaped electrode located on the surface of the fifth electrode G5 facing the first intermediate electrode Gm1 side, that is, on the first intermediate electrode Gm1 side of the fifth electrode G5. A pair of convex portions 31 extending in the horizontal direction so as to sandwich the opening portion 30 from the vertical direction on the bottom surface of the
Is provided, and the fifth electrode G5 of the first intermediate electrode Gm1 is provided.
A plurality of protrusions 42 extending in the vertical direction are provided on the side facing surface so as to sandwich the opening 41 from the horizontal direction.

On the other hand, in another embodiment,
As shown in FIGS. 12 to 14, the first electrode G5
On the bottom surface of the cup-shaped electrode located on the intermediate electrode Gm1 side,
The cylindrical electrode 36 is provided on the side facing the first intermediate electrode Gm1. The cylindrical electrode 36 has an opening 37 common to three electron beams having the long side in the horizontal direction which is the same as the arrangement of the three cathodes.

That is, similarly to the above-described embodiment, by providing the cylindrical electrode 36 on the surface of the fifth electrode G5 facing the first intermediate electrode Gm1, the fifth electrode G5 and the first intermediate electrode Gm1 are connected to each other. Of the cylindrical electrode 36 is reduced.
Is the same horizontal direction as the arrangement of the three cathodes KB, KG, and KR, so that the fifth electrode G5 and the first intermediate electrode G
A relatively strong asymmetric focusing electric field is formed between m1 and m1. Therefore, an electron gun structure having the same effects as those of the above-described embodiment can be formed.

In the above-described embodiment, the QPF type electron gun assembly has been described as an example.
(Bi-Potential Focus) type electron gun assembly, UPF (Uni-Poten
It is also applicable to other types of cathode ray tube electron gun structures, such as a tialFocus) type electron gun structure.

As described above, according to the electron gun structure for a cathode ray tube of the present invention, three cathodes arranged in a row in the horizontal direction on the same horizontal plane correspond to the electron beams emitted from the respective cathodes. A focusing electrode to which a first-level voltage is supplied, and a focusing electrode provided with three apertures formed in parallel in the horizontal direction.
At least one intermediate electrode having an opening formed corresponding to each electron beam that has passed through the opening of the focusing electrode, to which a second level voltage higher than the first level is supplied; While being arranged adjacent to the intermediate electrode,
A final acceleration electrode having an aperture formed corresponding to each electron beam passing through the aperture of the intermediate electrode, to which a third level voltage higher than the second level is supplied; A resistor that divides a voltage supplied to the electrode into a predetermined value and supplies the voltage to the intermediate electrode, and between the focusing electrode and the intermediate electrode, strongly focuses each electron beam relatively vertically. Forming an asymmetric focusing electric field having an effect, and forming an asymmetric diverging electric field having an action of strongly diverging an electron beam relatively vertically in the intermediate electrode and the final accelerating electrode; and In a cathode ray tube electron gun assembly for changing a voltage supplied to a focusing electrode in synchronization with the deflection of an electron beam, three apertures of the focusing electrode are vertically formed on a surface facing the intermediate electrode side of the focusing electrode. Horizontal direction to pinch Whether to provide a pair of convex portions extending or to provide a convex portion extending in the vertical direction on the opposing surface of the intermediate electrode on the focusing electrode side so as to sandwich the three opening portions of the intermediate electrode from the horizontal direction. , Combining these configurations,
Alternatively, a cylindrical electrode common to the three apertures of the focusing electrode and having a long side in the horizontal direction is provided on the surface facing the intermediate electrode of the focusing electrode.

The focusing electrode is supplied with a voltage in which a predetermined DC component voltage is superimposed on a voltage that changes in a parabolic manner as the deflection angle of the electron beam increases. With such a configuration, the capacitance between the focusing electrode and the intermediate electrode facing the focusing electrode is reduced, and the induction of a voltage to the intermediate electrode via the capacitance is prevented, and a predetermined electric field action is performed. Since the beam spot can be maintained and a strong asymmetric focusing electric field can be formed, the beam spot can be improved in the peripheral portion of the screen without increasing the parabolic electric field component superimposed on the focusing electrode. Since the vertical diameter of the electric field lens at the aperture of the focusing electrode can be increased, the electron beam can be focused without receiving the aberration of the electric field lens formed between the electrodes, and a good beam can be obtained over the entire screen. You can get a spot.

[0073]

As described above, according to the present invention, a good resolution can be realized over the entire screen with a relatively simple structure without increasing the parabolic voltage component applied to the focusing electrode. An electron gun assembly for a cathode ray tube can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the deflection aberration of a conventional self-convergence type in-line type color CRT.

FIG. 2 is a horizontal sectional view schematically showing a first structural example of an electron gun structure applied to a conventional cathode ray tube.

FIG. 3 is a vertical sectional view schematically showing a first structural example of an electron gun assembly applied to a conventional cathode ray tube.

FIG. 4 is a horizontal sectional view schematically showing a second structural example of an electron gun assembly applied to a conventional cathode ray tube.

FIG. 5 is a vertical sectional view schematically showing a first structural example of an electron gun structure applied to a conventional cathode ray tube.

FIG. 6 is a first view of the electron gun assembly shown in FIG. 5;
It is a perspective view which shows the structure of an intermediate electrode schematically.

FIG. 7 is a horizontal sectional view schematically showing the structure of a cathode ray tube to which the electron gun assembly of the present invention is applied.

FIG. 8 is a horizontal sectional view schematically showing a first structural example of an electron gun assembly for a cathode ray tube according to the present invention.

FIG. 9 is a vertical sectional view schematically showing a first structural example of an electron gun assembly for a cathode ray tube according to the present invention.

FIG. 10 is a perspective view schematically showing a structure of a fifth electrode in the electron gun structure shown in FIG. 9;

FIG. 11 is a perspective view schematically showing a structure of a first intermediate electrode in the electron gun assembly shown in FIG. 8;

FIG. 12 is a horizontal sectional view schematically showing a second structural example of the electron gun assembly for a cathode ray tube according to the present invention.

FIG. 13 is a vertical sectional view schematically showing a second structural example of the electron gun assembly for a cathode ray tube according to the present invention.

FIG. 14 is a perspective view schematically showing a structure of a cylindrical electrode disposed on a first intermediate electrode side of a fifth electrode in the electron gun structure shown in FIGS. 12 and 13.

[Explanation of symbols]

 K (R, G, B) cathode 20 panel 21 funnel 22 phosphor screen 23 shadow mask 24 neck 25 (R, G, B) electron beam 26 electron gun assembly 27 anode terminal 28 Internal conductive film 30 Opening part 31 Projecting part 32 Resistor 35 Variable resistor 36 Tubular electrode 37 Opening part 41 Opening part 41 Projecting part G1 First electrode G2 Second electrode G3: Third electrode G4: Fourth electrode G5: Fifth electrode G6: Sixth electrode SC: Shield cup Gm1: First intermediate electrode Gm2: Second intermediate electrode

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazunori Sato 1-9-2 Hara-cho, Fukaya-shi, Saitama F-term in Fukaya Electronics Factory, Toshiba Corporation (reference) 5C041 AA02 AA14 AB07 AB14 AC19 AC26 AC35 AD02 AE01

Claims (5)

[Claims] 1. Three cathodes arranged in a row in the horizontal direction on the same horizontal plane, and three apertures formed in parallel in the horizontal direction corresponding to each electron beam emitted from each cathode. A focusing electrode to which a first level voltage is supplied; and a focusing electrode disposed adjacent to the focusing electrode and formed corresponding to each electron beam that has passed through the aperture of the focusing electrode. At least one intermediate electrode, which has a hole formed therein and to which a second level voltage higher than the first level is supplied, and which is disposed adjacent to the intermediate electrode and has a hole formed in the intermediate electrode. A final accelerating electrode having an aperture formed corresponding to each electron beam passing through the portion, to which a third level voltage higher than the second level is supplied; and a voltage supplied to the final accelerating electrode. A resistor that is divided into predetermined values and supplied to the intermediate electrode; Forming an asymmetric focusing electric field having an action of strongly focusing each electron beam in the vertical direction relatively between the focusing electrode and the intermediate electrode; and forming an asymmetric focusing electric field between the intermediate electrode and the final accelerating electrode. An electron beam for a cathode ray tube which forms an asymmetric diverging electric field having an action of relatively strongly diverging an electron beam in a vertical direction and changes a voltage supplied to the focusing electrode in synchronization with the deflection of the electron beam. In the gun structure, a surface of the focusing electrode facing the intermediate electrode is
An electron gun assembly for a cathode ray tube, comprising a pair of projections extending in the horizontal direction that is the same as the arrangement direction of the three openings so as to sandwich the openings from the vertical direction. . 2. A cathode having three cathodes arranged in a row in the horizontal direction on the same horizontal plane, and an opening formed corresponding to each electron beam emitted from each cathode, A focusing electrode to which a voltage is supplied; and three focusing electrodes arranged adjacent to the focusing electrode and formed in parallel in the horizontal direction corresponding to each electron beam that has passed through the aperture of the focusing electrode. At least one intermediate electrode to which a second-level voltage higher than the first level is supplied, and which is disposed adjacent to the intermediate electrode and has a hole formed in the intermediate electrode. A final accelerating electrode having an aperture formed corresponding to each electron beam passing through the portion, to which a third level voltage higher than the second level is supplied; and a voltage supplied to the final accelerating electrode. A resistor that is divided into predetermined values and supplied to the intermediate electrode; Forming an asymmetric focusing electric field having an action of strongly focusing each electron beam in the vertical direction relatively between the focusing electrode and the intermediate electrode; and forming an asymmetric focusing electric field between the intermediate electrode and the final accelerating electrode. In between, an asymmetric diverging electric field having an action of strongly diverging the electron beam relatively vertically is formed, and the voltage supplied to the focusing electrode is changed in synchronization with the deflection of the electron beam. In the gun structure, the surface of the intermediate electrode facing the focusing electrode is
An electron gun assembly for a cathode ray tube, wherein a projection extending in a vertical direction is provided so as to sandwich the apertures from a horizontal direction. 3. Three cathodes arranged in a row in the horizontal direction on the same horizontal plane, and three apertures formed in parallel in the horizontal direction corresponding to each electron beam emitted from each cathode. A focusing electrode to which a first-level voltage is supplied; and a focusing electrode arranged adjacent to the focusing electrode, the horizontal direction corresponding to each electron beam passing through the aperture of the focusing electrode. At least one intermediate electrode having three apertures formed in parallel to each other and supplied with a second level voltage higher than the first level; and being arranged adjacent to the intermediate electrode. A final accelerating electrode having an aperture formed corresponding to each electron beam passing through the aperture of the intermediate electrode, wherein a third level voltage higher than the second level is supplied; Dividing the voltage supplied to the final accelerating electrode into a predetermined value, A resistor for supplying to the inter-electrode, between the focusing electrode and the intermediate electrode, forming an asymmetric focusing electric field having an action of strongly focusing each electron beam relatively vertically. Between the electrode and the final accelerating electrode, an asymmetric diverging electric field having an action of strongly diverging the electron beam relatively vertically is formed, and a voltage supplied to the focusing electrode is used to deflect the electron beam. In the electron gun assembly for a cathode ray tube, which is changed synchronously, a surface of the focusing electrode,
A pair of protrusions extending in the horizontal direction are provided so as to sandwich the opening portions from the vertical direction.
An electron gun assembly for a cathode ray tube, wherein a projection extending in a vertical direction is provided so as to sandwich the apertures from a horizontal direction. 4. Three cathodes arranged in a row in the horizontal direction on the same horizontal plane, and three apertures formed in parallel in the horizontal direction corresponding to each electron beam emitted from each cathode. A focusing electrode to which a first level voltage is supplied; and a focusing electrode disposed adjacent to the focusing electrode and formed corresponding to each electron beam that has passed through the aperture of the focusing electrode. At least one intermediate electrode, which has a hole formed therein and to which a second level voltage higher than the first level is supplied, and which is disposed adjacent to the intermediate electrode and has a hole formed in the intermediate electrode. A final accelerating electrode having an aperture formed corresponding to each electron beam passing through the portion, to which a third level voltage higher than the second level is supplied; and a voltage supplied to the final accelerating electrode. A resistor that is divided into predetermined values and supplied to the intermediate electrode; Forming an asymmetric focusing electric field having an action of strongly focusing each electron beam in the vertical direction relatively between the focusing electrode and the intermediate electrode; and forming an asymmetric focusing electric field between the intermediate electrode and the final accelerating electrode. An electron beam for a cathode ray tube which forms an asymmetric diverging electric field having an action of relatively strongly diverging an electron beam in a vertical direction and changes a voltage supplied to the focusing electrode in synchronization with the deflection of the electron beam. In the gun structure, a surface of the focusing electrode facing the intermediate electrode is
An electron gun assembly for a cathode ray tube, wherein a common cylindrical electrode having a long side in the horizontal direction is provided in each of the openings. 5. A voltage in which a predetermined DC component voltage is superimposed on a voltage that changes in a parabolic manner with an increase in the deflection angle of an electron beam is supplied to the focusing electrode. The electron gun assembly for a cathode ray tube according to any one of claims 1 to 4.