JP2002237261A - Cathode-ray tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube device allowing electron beams to be focused in the optimum condition on the whole surface of a phosphor screen, elliptic distortion of a beam spot to be relaxed and a good quality image to be displayed. SOLUTION: A electron gun structure comprises an electron beam generation part for generating electron beams and an electron lens part for accelerating the electron beams toward the phosphor screen and focusing them on the phosphor screen. At least one electrode GS forming the electron lens part is a predetermined-thickness plate electrode having electron beam passing holes 31 (R, G, B) and the edge of the plate electrode forming the electron beam passing holes 31 (R, G, B) contains protruded portions 32 which are formed partially thicker in the horizontal direction than predetermined thickness in a region where an electron lens substantially effected on the electron beams is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube device, and more particularly to a color cathode ray tube device which displays a high quality image by reducing elliptic distortion of a beam spot in a peripheral portion of a screen.

[0002]

2. Description of the Related Art At present, BPF (Bi-Potentia)
l Focus) DAC & F (Dynamic As)
Tigmatism Correction and
2. Description of the Related Art A self-convergence in-line type color cathode ray tube device having an electron gun structure of a (Focus) type has been widely put into practical use.

As shown in FIG. 13, this BPF type DAC & F type electron gun assembly has three cathodes K arranged in a line, and a first grid G1 arranged in the direction of the phosphor screen from the cathodes K in order. Second grid G2
Two segments G3-1 and G3- of the third grid G3
2 and a fourth grid G4. Each grid has three electron beam passage holes arranged in a row corresponding to the three cathodes K, respectively.

A voltage obtained by superimposing a video signal on a voltage of about 150 V is applied to the cathode K. First grid G1
Is grounded. In the second grid G2, about 600
A voltage of V is applied. A DC voltage of about 6 kV is applied to the first segment G3-1 of the third grid. Third
A dynamic voltage is applied to the second segment G3-2 of the grid in which a DC voltage of about 6 kV is superimposed with a parabolic AC voltage component Vd that rises with an increase in the amount of deflection of the electron beam. The fourth grid G4 has approximately 26k
A voltage of V is applied.

[0005] The electron beam generator is formed by the cathode K, the first grid G1, and the second grid G2.
It generates an electron beam and forms an object point for the main lens. The prefocus lens is formed by the second grid G2 and the first segment G3-1, and prefocuses the electron beam generated from the electron beam generator. BPF
The mold main lens is formed by the second segment G3-2 and the fourth grid G4, accelerates the pre-focused electron beam toward the phosphor screen, and finally focuses on the phosphor screen.

When the electron beam is deflected to the corner of the phosphor screen, the potential difference between the second segment G3-2 and the fourth grid G4 is minimized, and the intensity of the main lens formed between them is reduced. Is the weakest. at the same time,
A maximum potential difference is formed between the first segment G3-1 and the second segment G3-2, and a quadrupole lens having a focusing action in the horizontal direction and a diverging action in the vertical direction is formed.
At this time, the intensity of the quadrupole lens becomes the strongest.

When the electron beam is deflected to the corner of the phosphor screen, the distance from the electron gun structure to the phosphor screen becomes the largest, and the image point becomes far. In the above-mentioned BPF type DAC & F electron gun assembly, the distant image point is compensated by weakening the strength of the main lens. The deflection aberration generated by the pincushion-type horizontal deflection magnetic field and the barrel-type vertical deflection magnetic field for deflecting the electron beam is compensated by forming a quadrupole lens.

Incidentally, in order to improve the image quality of the color cathode ray tube device, it is necessary to improve the focus characteristics and the shape of the beam spot over the entire area of the phosphor screen. However, in the conventional in-line type color cathode ray tube device, as shown in FIG. 14A, the beam spot at the center of the phosphor screen is circular.
The beam spot at the periphery of the phosphor screen is distorted (collapsed) in the shape of a long ellipse in the horizontal axis (X axis) direction and bleeds in the vertical axis (Y axis) direction due to deflection aberration, thereby deteriorating the image quality.

In order to cope with this, in the above-mentioned BPF type DAC & F type electron gun assembly, the low voltage side grid forming the main lens is divided into a plurality of segments like a third grid G3 as shown in FIG. By forming a quadrupole lens in which the lens intensity dynamically changes according to the amount of deflection of the electron beam between these segments, the bleeding of the beam spot is reduced as shown in FIG. Can be eliminated.

However, also in the BPF type DAC & F type electron gun structure, as shown in FIG.
The beam spot at the periphery of the phosphor screen causes a collapse in the horizontal direction. For this reason, moire or the like is generated due to interference with the shadow mask, and when characters or the like are displayed at the beam spot, there is a problem that it is difficult to see.

The crushing of the beam spot will be described with reference to optical models shown in FIGS. FIG. 15A is an optical model in a case where the electron beam is incident on the center of the phosphor screen without being deflected, and FIG. 15B is a diagram in which the deflected electron beam is emitted from the phosphor screen. It is an optical model in a case where light enters a peripheral portion. Here, ML is a main lens, QL is a quadrupole lens, D
Y is a deflection aberration component formed by the deflection magnetic field.

Generally, the size of the beam spot on the phosphor screen depends on the magnification M. The magnification M
Is represented by a ratio M = α0 / αi between the divergence angle α0 of the electron beam and the incident angle αi on the phosphor screen. Therefore, the horizontal magnification Mh1 and the vertical magnification Mv1 are:
When the divergence angle in the horizontal direction is α0h1, the incident angle is αih1, the divergence angle in the vertical direction is α0v1, and the input angle is αiv1, Mh1 = α0h1 / αih1 Mv1 = α0v1 / αiv1.

Therefore, when α0h1 = α0v1, when there is no deflection as shown in FIG. 15 (a), αih1 = αiv1 mainly due to the main lens ML having a uniform focusing action in the horizontal and vertical directions. Mh1 = Mv1. Therefore, the beam spot is circular at the center of the phosphor screen. On the other hand, at the time of the deflection shown in FIG. 15B, in order to compensate for the deflection aberration component DY of the deflection magnetic field having a diverging action in the horizontal direction and a focusing action in the vertical direction, the focusing action in the horizontal direction is performed. Since the quadrupole lens QL having the diverging function in the vertical direction is formed before the main lens ML, αih1 <αiv1 and Mh1> Mv1. Therefore, at the periphery of the phosphor screen,
The beam spot is horizontally long.

As a method of alleviating the lateral distortion of the beam spot at the periphery of the phosphor screen, there is a method of forming a quadrupole lens in the main lens. This method is described in FIG.
This will be described with reference to the optical model shown in FIG.

That is, the horizontal magnification Mh2, and
The magnification in the vertical direction is Mv2, and the divergence angle in the horizontal direction is α0h
2. The incident angle is αih2, the vertical divergence angle is α0v2,
Assuming that the input angle is αiv2, Mh2 = α0h2 / αih2 Mv2 = α0v2 / αiv2.

Further, when the quadrupole lens QL approaches the deflection aberration component DY, α0h1 = α0h2, α0v1 = α0v2, αih1> αih2, and αiv1> αiv2. That is, Mh2 <Mh1, Mv2> Mv1. Therefore, the ellipticity of the beam spot at the periphery of the phosphor screen is reduced as shown in FIG.

More specifically, as a method of forming a quadrupole lens in the main lens, as shown in FIG. 18, a disc-shaped additional electrode Gs is arranged at the center between the focus electrode G3 and the anode electrode G4. A method of applying an intermediate voltage between the applied voltage of the focus electrode G3 and the applied electrode of the anode electrode G4. As shown in FIG. 19, this additional electrode Gs has three vertically long electron beam passing lights corresponding to three cathodes.

A parabolic voltage that rises with an increase in the amount of electron beam deflection is applied to the focus electrode G3 in synchronization with the change in the deflection magnetic field as shown in FIG. When the voltage of the focus electrode G3 increases, the potential difference between the focus electrode G3 and the additional electrode Gs decreases, and the potential difference between the additional electrode Gs and the anode electrode G4 increases. As a result, potential penetration occurs in the electron beam passage hole of the additional electrode Gs, and a focusing force difference occurs between the horizontal direction and the vertical direction of the electron beam, thereby forming a quadrupole lens function in the main lens.

However, in practice, this method has a disadvantage that the quadrupole action of the lens formed by the potential penetration into the electron beam passage hole of the additional electrode Gs is small.
That is, the necessary quadrupole action is insufficient when the electron beam is deflected to the periphery of the phosphor screen. As shown in FIG. 21, the electron beam deflected toward the periphery of the phosphor screen is focused in the horizontal direction. Phenomena such as insufficiency and overfocusing in the vertical direction occur, and good image quality cannot be obtained.

[0020]

As described above, in order to improve the image quality of the color cathode ray tube device, it is necessary to maintain a good focus state over the entire phosphor screen and to reduce the elliptic distortion of the beam spot. is necessary.

In a conventional BPF-type DAC & F type electron gun assembly, a quadrupole lens which dynamically changes at the same time as changing the main lens strength is formed by applying an appropriate parabola voltage to a focus electrode forming the main lens. are doing.
This eliminates vertical bleeding of the beam spot due to deflection aberration and focuses on the entire phosphor screen.

However, in the BPF type DAC & F type electron gun assembly, it is not possible to eliminate the collapsing of the beam spot at the periphery of the phosphor screen. This phenomenon occurs because the horizontal magnification Mh and the vertical magnification Mv are in a relationship of Mv> Mh due to astigmatism of the electron lens and the deflection magnetic field when the electron beam is deflected toward the periphery of the phosphor screen. Things.

As a countermeasure against this, a method of forming a quadrupole lens in the main lens by configuring as shown in FIGS. 18 to 20 is effective. However, in the above-described configuration, a sufficient quadrupole lens effect cannot be obtained, and the beam spot around the phosphor screen is insufficiently focused in the horizontal direction and overfocused in the vertical direction, thereby obtaining good image quality. Can not do.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The present invention focuses an electron beam on the entire surface of a phosphor screen in an optimal state, reduces elliptic distortion of a beam spot, and provides good image quality. It is an object to provide a cathode ray tube device capable of displaying an image.

[0025]

According to a first aspect of the present invention, there is provided a cathode ray tube device for generating an electron beam, and an electron beam generating unit for generating an electron beam. An electron lens unit that accelerates the electron beam toward the phosphor screen and focuses the electron beam on the phosphor screen, and emits the electron beam emitted from the electron gun assembly in the horizontal direction of the phosphor screen and A deflection yoke that generates a deflection magnetic field that deflects in the vertical direction, wherein at least one electrode forming the electron lens portion is a plate-shaped electrode having a predetermined thickness and having an electron beam passage hole. The edge of the plate-like electrode forming the electron beam passage hole has a horizontal plate thickness in a region where an electron lens substantially acting on an electron beam is formed. Wherein the predetermined plate is thicker than the thickness to.

According to a third aspect of the present invention, there is provided a cathode ray tube device, wherein an electron beam generating section for generating an electron beam, and an electron beam generated from the electron beam generating section are accelerated toward the phosphor screen, and are accelerated on the phosphor screen. A cathode ray line comprising: an electron gun assembly having an electron lens portion for focusing; and a deflection yoke for generating a deflection magnetic field for deflecting an electron beam emitted from the electron gun assembly in a horizontal direction and a vertical direction of a phosphor screen. In the tube device, at least one electrode forming the electron lens portion is a plate-shaped electrode having a predetermined thickness provided with an electron beam passage hole, and an edge of the plate electrode forming the electron beam passage hole is In a region where an electron lens which substantially acts on an electron beam is formed, a plate thickness in a vertical direction is partially formed to be larger than the predetermined plate thickness.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the cathode ray tube device of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a cathode ray tube device, that is, an in-line type color cathode ray tube device, comprises an enclosure comprising a panel 1, a neck 5, and a funnel funnel 2 integrally joining the panel 1 and the neck 5. It has a vessel. The panel 1 has on its inner surface a phosphor screen 3 composed of a three-color phosphor layer in the form of dots or stripes that emit blue, green, and red light. The shadow mask 4 has a number of electron beam passage holes inside thereof, and is arranged to face the phosphor screen 3.

The neck 5 has an in-line type electron gun structure 7 disposed therein. This electron gun structure 7
Emits three electron beams 6B, 6G, 6R arranged in a line composed of a center beam 6G and a pair of side beams 6B, 6R passing on the same horizontal plane.

The deflection yoke 8 is mounted from the large diameter portion of the funnel 2 to the neck 5. This deflection yoke 8
Are three electron beams 6B and 6 emitted from the electron gun assembly 7.
A non-uniform deflection magnetic field that deflects G and 6R in the horizontal direction (X) and the vertical direction (Y) is generated. This non-uniform magnetic field is formed by a pincushion-type horizontal deflection magnetic field and a barrel-type vertical deflection magnetic field.

The three electron beams 6 B, 6 G, and 6 R emitted from the electron gun assembly 7 are deflected by the asymmetric magnetic field generated by the deflection yoke 8 and move the phosphor screen 3 through the shadow mask 4 in the horizontal direction X and the vertical direction. Scan in the direction Y. Thereby, a color image is displayed.

As shown in FIG. 2, the electron gun assembly 7 has three cathodes K (R, R, R) arranged in a line in the horizontal direction (X).
G, B), three heaters for individually heating these cathodes K (R, G, B), and five electrodes. The five electrodes, namely the first grid G1, the second grid G2, the third grid (focus electrode) G3, the additional electrode Gs, and the fourth grid (anode electrode) G4,
The cathodes K (R, G, B) are sequentially arranged in the direction of the phosphor screen. These heater, cathode K
(R, G, B) and the five electrodes are integrally fixed by a pair of insulating supports.

Each of the first and second grids G1 and G2 is constituted by a plate electrode having an integral structure. These plate-like electrodes have three circular electron beam passage holes formed in a row in the horizontal direction X corresponding to the three cathodes K (R, G, B). The third grid G3 is configured by a cylindrical electrode having an integral structure. This cylindrical electrode has three cathodes K on its both end surfaces, that is, a surface facing the second grid G2 and a surface facing the additional electrode Gs.
It has three circular electron beam passage holes formed in a row in the horizontal direction X corresponding to (R, G, B). The fourth grid G4 is configured by a cylindrical electrode having an integral structure. This cylindrical electrode has both end faces, that is, the additional electrode G
s and three end faces on the phosphor screen side having three circular electron beam passage holes formed in a row in the horizontal direction corresponding to the three cathodes K (R, G, B). I have.

The additional electrode Gs is connected to the third grid G3 and the fourth grid G3.
It is arranged at a geometric center between the grid G4, that is, at a position equidistant from the third grid G3 and the fourth grid G4. This additional electrode Gs, as shown in FIG.
Three non-circular electron beam passage holes 31R formed in a row in the horizontal direction X corresponding to the three cathodes K (R, G, B); 31G,
31B. These electron beam passage holes 31
(R, G, B) are, for example, vertically long holes having the long axis in the vertical direction Y as shown in FIG.

This plate-like electrode is provided with an electron beam passage hole 31.
At the edge forming (R, G, B), there is a protruding portion 32 that is formed partially thicker. This protrusion 32
Are integrally formed by forming the plate-shaped electrode to be thicker than a predetermined plate thickness. The protruding portion 32 is provided symmetrically in the horizontal direction in a region where an electron lens substantially acting on an electron beam is formed.

Here, a method for forming a quadrupole lens having a sufficiently dynamic lens strength in the main lens, in which the electron beam is finally accelerated on the phosphor screen and converged, will be described.

First, a general rotationally symmetric BPF type main lens will be described.

The rotationally symmetric BPF type main lens is formed by an electric field symmetrical in the horizontal direction (X) and the vertical direction (Y) as shown by the equipotential surface 20 in FIG. This main lens focuses the electron beam 9 in the vertical direction and the electron beam 10 in the horizontal direction with the same focusing power. The center axis Z of the focus electrode 11 and the anode electrode 12 forming this main lens
The upper potential (on-axis potential) increases along the traveling direction of the electron beams 9, 10 as shown by the curve 22a. In this case, for example, the applied voltage to the focus electrode 11 is 6 kV,
Assuming that the voltage applied to the anode electrode 12 is 26 kV, the equipotential surface 23 formed at the geometric center of this main lens (position equidistant from the focus electrode and the anode electrode)
Becomes a plane and has a potential of 16 kV.

Next, the case where the additional electrode 13 is arranged at the geometric center of the main lens as shown in FIG. 5 will be described. The additional electrode 13 is formed by a plate-like electrode having a vertically long electron beam passage hole having a long axis in the vertical direction Y on the plate surface. 6k for focus electrode 11
When a voltage of V is applied and a voltage of 26 kV is applied to the anode electrode 12, a potential of 16 kV is applied to the additional electrode 13. At this time, the on-axis potential of the main lens is represented by a curve 2
As shown by 2b, the potential distribution is the same as when the additional electrode shown in FIG. 4 is not arranged. Therefore, this main lens focuses the electron beams 9 and 10 in the horizontal and vertical directions with the same focusing force.

Subsequently, as shown in FIG.
A case in which a voltage lower than 16 kV is applied to the above will be described. The potential of the additional electrode 13 on the anode electrode 12 side penetrates into the focus electrode 11 side through the electron beam passage hole of the additional electrode 13. Thus, an aperture lens (quadrupole lens) is formed inside the main lens. In this case, the on-axis potential of the main lens is as shown by the curve 22c. Since the electron beam passage hole of the additional electrode 13 is vertically long, the aperture lens formed in the main lens has a relatively strong focusing force with respect to the electron beams 9 and 10 in the horizontal direction and also has a strong focusing force in the vertical direction. Has relatively weak focusing power. That is, the main lens has astigmatism. However, since the aperture lens focuses the electron beam in both the horizontal and vertical directions, it cannot form sufficiently strong astigmatism.

On the other hand, the projecting portion 32 symmetrical along the horizontal direction as shown in FIG.
Additional electrodes Gs provided along the edges of (R, G, B)
The case where the lens is arranged at the geometric center of the main lens will be described. That is, the additional electrode Gs disposed at the geometric center of the rotationally symmetric BPF type main lens has the vertically elongated electron beam passage holes 31 (R, G, B) having a long axis in the vertical direction. This non-circular electron beam passage hole 31 (R,
G, B), the edge of the plate electrode forming the electron beam 9,
In a region through which 10 passes, a protruding portion 32 having a plate thickness is provided in the horizontal direction.

When the applied voltage of the focus electrode G3 is set to 6 kV, the applied voltage of the additional electrode Gs is set to 16 kV, and the applied voltage of the anode electrode G4 is set to 26 kV, the main lens having the above-mentioned configuration has a curve 22d. 5 has the same potential distribution as the on-axis potential of the main lens. Therefore, this main lens focuses the electron beams 9 and 10 in the horizontal direction and the vertical direction with the same focusing force, similarly to the main lens having no additional electrode.

Next, a case where a voltage lower than 16 kV is applied to the additional electrode Gs will be described. As shown in FIG. 8, the potential of the additional electrode Gs on the anode electrode G4 side penetrates into the focus electrode G3 side through the electron beam passage hole 31 of the additional electrode Gs. Thus, an aperture lens (quadrupole lens) is formed inside the main lens. In this case, the axial potential of the main lens is as shown by the curve 22e.

Since the projection 32 having a large thickness is provided at a position intersecting the horizontal axis X of the additional electrode Gs, the potential permeated through the electron beam passage hole 31 is equal to the equipotential surface as shown in FIG. 20a. That is, the equipotential surface 20a
In the horizontal direction (X), as it approaches the central axis Z from the periphery of the electron beam passage hole 31, it gradually penetrates to the focus electrode G3 side and penetrates most near the central axis Z. Further, in the vertical direction (Y), the equipotential surface 20a penetrates most in the middle of permeating the focus electrode G3 as it approaches the central axis Z from the periphery of the electron beam passage hole 31 and further penetrates the central axis Z. As you get closer,
The degree of penetration is reduced. As a result, the aperture lens (quadrupole lens) formed by the penetration of the electric potential has a relatively strong focusing action in the horizontal direction X and a relatively divergent action in the vertical direction Y. Thus, the aperture lens focuses the electron beam 10 in the horizontal direction and diverges the electron beam 9 in the vertical direction. Therefore, the main lens can form sufficiently strong astigmatism.

Next, a case where a voltage higher than 16 kV is applied to the additional electrode Gs will be described. As shown in FIG. 9, the potential of the additional electrode Gs on the focus electrode G3 side is
It penetrates to the anode electrode G4 side through the electron beam passage hole 31 of the additional electrode Gs. Thus, an aperture lens (quadrupole lens) is formed inside the main lens. In this case, the potential on the axis of the main lens is as shown by the curve 22f.

By providing the projecting portion 32 at a position intersecting with the horizontal axis X of the additional electrode Gs, the potential penetrating through the electron beam passage hole 31 is equal to the equipotential surface 20b as shown in FIG. Become. That is, this equipotential surface 20b
In the horizontal direction X, as the distance from the periphery of the electron beam passage hole 31 to the central axis Z increases, the anode electrode G gradually decreases.
It penetrates to the side 4 and penetrates most near the central axis Z. Further, in the vertical direction Y, as the equipotential surface 20b approaches the central axis Z from the periphery of the electron beam passage hole 31,
It penetrates most on the way to the anode electrode G4 side, and the degree of penetration becomes smaller as it approaches the central axis Z. As a result, the aperture lens (quadrupole lens) formed by the penetration of the electric potential has a relatively diverging action in the horizontal direction X and a relatively focusing action in the vertical direction Y. Accordingly, the aperture lens diverges the electron beam 10 in the horizontal direction X and converges the electron beam 10 in the vertical direction Y. Therefore, the main lens can form sufficiently strong astigmatism.

That is, the rotationally symmetric BPF type main lens according to this embodiment has the additional electrode Gs disposed at the geometric center. The additional electrode Gs has a vertically long electron beam passage hole 31 having a long axis in the vertical direction (Y). The edge of the plate-like electrode forming the non-circular electron beam passage hole 31 forms an electron lens acting on the electron beam passing through the electron beam passage hole 31 near a position intersecting the horizontal axis X. For this purpose, it has a protruding portion 32 having a large plate thickness. By applying a dynamically changing voltage higher than the voltage applied to the focus electrode G3 and lower than the voltage applied to the anode electrode G4 to the additional electrode Gs, without impairing the aperture of the main lens, Astigmatism that controls the horizontal focusing power and the vertical focusing power can be formed.

In the above description, the case where the voltage applied to the additional electrode is changed has been described. Instead of changing the voltage applied to the additional electrode, [(applied voltage of additional electrode) − (applied voltage of focus electrode) )] / [(Applied voltage of anode electrode) − (applied voltage of focus electrode)], the same result can be obtained.

In the electron gun assembly 7 having the above-described configuration, a voltage obtained by superimposing a video signal on a DC voltage of 150 V is applied to the cathode K. The first grid G1 is grounded. A DC voltage of about 600 V is applied to the second grid G2. As shown in FIG. 20, to the third grid G3, a dynamic focus voltage 40 in which an AC voltage component Vd that changes in a parabolic manner is superimposed on a DC voltage of about 6 kV is applied. The AC voltage component Vd is synchronized with the sawtooth-shaped deflection current 9 and rises in a parabolic manner as the amount of deflection of the electron beam increases. In the fourth grid G4,
An anode voltage Eb of about 26 kV is applied. Additional electrode Gs
Is applied with a DC voltage of about 16 kV.

The electron gun assembly 7 forms an electron beam generator, a prefocus lens, and a main lens by applying the above-described voltage to each grid. The electron beam generator is formed by the cathode K, the first grid G1, and the second grid G2. The electron beam generator generates an electron beam and forms an object point with respect to the main lens. The prefocus lens is formed by the second grid G2 and the third grid G3. The prefocus lens preliminarily focuses the electron beam generated from the electron beam generation unit.

The main lens is formed by the third grid G3 (focus electrode), the additional electrode Gs, and the fourth grid G4 (anode electrode). The main lens finally focuses the electron beam prefocused by the prefocus lens on the phosphor screen. In addition, at the time of deflection, the main lens includes the third grid G3 and the fourth grid G4.
And the additional electrode Gs disposed between the
Form a pole lens.

When the electron beams 6B, 6G and 6R are focused on the central portion of the phosphor screen 3 when there is no deflection, the main lens formed by the third to fourth grids G3 to G4 is as shown in FIG. Since it is formed by a simple electric field 20, it has no astigmatism. Therefore, each of the electron beams 6B, 6G, and 6R generated from the electron beam generator is focused by the prefocus lens and the main lens with the same focusing force in the horizontal and vertical directions. For this reason, each of the electron beams 6B, 6G, 6R is focused on the central portion of the phosphor screen 3, and forms a substantially circular beam spot.

When each electron beam 6B, 6G, 6R is deflected toward the periphery of the phosphor screen 3, the dynamic focus voltage applied to the third grid G3 as the amount of electron beam deflection increases. 40 increase. At this time, [(applied voltage of additional electrode) − (applied voltage of third grid)] / [(applied voltage of fourth grid) − (applied voltage of third grid)] That is, [(applied voltage of additional electrode) ) − (Applied voltage of focus electrode)] / [(applied voltage of anode electrode) − (applied voltage of focus electrode)] becomes smaller than when no deflection is performed.

In this case, the projections 3 are formed at the edges of the additional electrodes Gs where the electron beam passage holes 31B, 31G, 31R are formed.
2, the main lens is formed by the electric field 20 as shown in FIG. Therefore, this main lens has astigmatism. That is, an aperture lens (quadrupole lens) having a converging action in the horizontal direction and a diverging action in the vertical direction is formed inside the main lens. At the same time, the potential difference between the third grid G3 and the fourth grid G4 decreases. As a result, an effect of reducing the horizontal focusing power and the vertical focusing power of the main lens occurs.

In the electron gun assembly 29, the main lens having the quadrupole lens formed therein has a focusing force which is increased in the horizontal direction by the projection 32 of the additional electrode Gs, and the third grid G3 and the fourth grid G4. And the focusing power, which is weakened by the decrease in the potential difference between the two, is canceled out.

Further, in the electron gun assembly 29, the main lens has a protruding portion 32 of the additional electrode Gs in the vertical direction.
Divergence formed by the third grid G3 and the fourth grid G3
It has a relatively divergent effect due to the focusing power which is weakened by the decrease in the potential difference from the grid G4.

As described above, at the time of deflection, the main lens has astigmatism, that is, it has a relatively weak focusing power in its horizontal direction and a diverging power in its vertical direction. As a result, conditions for optimally focusing the electron beam on the phosphor screen 3 are satisfied, and the ellipticity of the beam spot shape of the focused electron beam can be improved, and a substantially circular beam spot can be obtained. It becomes possible.

The third grid G3 and the fourth grid G
In the case where the bipotential main lens formed by step 4 is configured as an electron lens in which the horizontal focusing power is stronger than the vertical focusing power, the voltage applied to the additional electrode Gs is lower than 16 kV during non-deflection. By setting (that is, applying a potential lower than the potential at the geometric center of the main lens to the additional electrode Gs), the same effect as in the above-described embodiment can be obtained. Further, an AC voltage component that changes in a parabolic manner is superimposed on the third grid G3 during deflection, and [(applied voltage of additional electrode) − (applied voltage of third grid)] / [(applied voltage of fourth grid) − (Applied voltage of the third grid)] is smaller than that in the non-deflection state, and is weakened by the horizontal focusing force that is increased by the effect of the additional electrode and the decrease in the potential difference between the third grid G3 and the fourth grid G4. By configuring so as to cancel the horizontal focusing force, the same effect as in the above-described embodiment can be obtained.

The shape of the thick protrusion 32 formed on the additional electrode Gs is not limited to the shape shown in FIG. 3, but is formed in a screen shape as shown in FIG. You may. Even when the additional electrode Gs having the protrusion 32 having such a shape is used, the same effect as that of the above-described embodiment can be obtained.

Further, as shown in FIG.
The plate-like electrode constituting s is formed with an electron beam passage hole 31 (R,
G, B), at the edges forming the projections 32, which are partially thick,
(R, G, B) may be configured to have a constricted portion 33 that minimizes the horizontal diameter of a region through which the electron beam passes. That is, the edge of the plate-like electrode forming the constricted portion 33 is formed by the protrusion 32 which is formed partially thick.

As described above, in the case where the electron beam passage hole formed in the additional electrode Gs is formed in such a shape that the plate thickness is large in the horizontal direction and the constriction is such that the electron beam passage hole in the horizontal direction is small. The effect of the astigmatism that occurs can be further enhanced by the same operation as that of the embodiment.

That is, as shown in FIG. 10, the projection 32 symmetrical along the horizontal direction is
An additional electrode Gs provided along the edge of (R, G, B) and having a constricted portion 33 that minimizes the horizontal diameter of the electron beam passage hole 31 (R, G, B) is provided on the main lens. The case of disposing at the geometric center will be described. In other words, the additional electrode Gs disposed at the geometric center of the rotationally symmetric BPF type main lens has a vertically elongated major axis and a vertically elongated electron beam passage hole 31 having a constricted portion 33 having a minimum horizontal diameter. (R, G, B). The edge of the plate-like electrode forming the non-circular electron beam passage hole 31 (R, G, B) has a plate-like projection 32 in the horizontal direction in a region where the electron beams 9 and 10 pass. Have.

When the applied voltage of the focus electrode G3 is set to 6 kV, the applied voltage of the additional electrode Gs is set to 16 kV, and the applied voltage of the anode electrode G4 is set to 26 kV, the main lens having the above-mentioned configuration has a curve 22d as shown in FIG. 7 has the same potential distribution as the on-axis potential of the main lens. Therefore, this main lens focuses the electron beams 9 and 10 in the horizontal direction and the vertical direction with the same focusing force, similarly to the main lens having no additional electrode.

Next, a case where a voltage lower than 16 kV is applied to the additional electrode Gs will be described. As shown in FIG. 11, the potential of the additional electrode Gs on the anode electrode G4 side is:
It penetrates into the focus electrode G3 side through the electron beam passage hole 31 of the additional electrode Gs. Thus, an aperture lens (quadrupole lens) is formed inside the main lens. In this case, the axial potential of the main lens is as shown by the curve 22e.

At the position intersecting with the horizontal axis X of the additional electrode Gs, the projection 32 having a large thickness and the constriction 33 for regulating the horizontal diameter of the electron beam passage hole are provided. The electric potential penetrating through becomes the equipotential surface 20c as shown in FIG. That is, in the horizontal direction (X), as the equipotential surface 20 c approaches the central axis Z from the periphery of the electron beam passage hole 31,
It gradually penetrates to the focus electrode G3 side and penetrates most near the central axis Z. Further, in the vertical direction (Y), the equipotential surface 20 c penetrates the most in the middle of the permeation toward the focus electrode G <b> 3 as it approaches the central axis Z from the periphery of the electron beam passage hole 31, and further penetrates the central axis Z. As it approaches, the degree of penetration decreases.

As a result, the aperture lens (quadrupole lens) formed by the penetration of the electric potential has a relatively strong focusing action in the horizontal direction X and a relatively divergent action in the vertical direction Y. Thus, the aperture lens focuses the electron beam 10 in the horizontal direction, and
The electron beam 9 diverges in the vertical direction. Accordingly, the main lens can form stronger astigmatism than when the additional electrode shown in FIG. 3 is used.

Next, a case where a voltage higher than 16 kV is applied to the additional electrode Gs will be described. As shown in FIG. 12, the potential of the additional electrode Gs on the focus electrode G3 side penetrates to the anode electrode G4 side through the electron beam passage hole 31 of the additional electrode Gs. Thus, an aperture lens (quadrupole lens) is formed inside the main lens.
In this case, the potential on the axis of the main lens is as shown by the curve 22f.

The projection 32 is provided at a position intersecting the horizontal axis X of the additional electrode Gs, and the constriction 33 for regulating the horizontal diameter of the electron beam passage hole is provided. The potential that has permeated through becomes the equipotential surface 20d as shown in FIG. That is, in the horizontal direction X, the equipotential surface 20d gradually penetrates to the anode electrode G4 side from the periphery of the electron beam passage hole 31 to the central axis Z, and penetrates most near the central axis Z. In the vertical direction Y, the equipotential surface 20d penetrates the most along the anode electrode G4 side as it approaches the central axis Z from the periphery of the electron beam passage hole 31, and further approaches the central axis Z. , The degree of penetration decreases.

As a result, the aperture lens (quadrupole lens) formed by the penetration of the electric potential has a relatively diverging effect in the horizontal direction X and a relatively focusing effect in the vertical direction Y. Thereby, the aperture lens diverges the electron beam 10 in the horizontal direction X,
Focus in the vertical direction Y. Therefore, the main lens is shown in FIG.
It is possible to form stronger astigmatism than when the additional electrode shown in FIG.

That is, the rotationally symmetric BPF type main lens according to this embodiment has the additional electrode Gs disposed at the geometric center. The additional electrode Gs has a vertically long electron beam passage hole 31 having a long axis in the vertical direction (Y). The edge of the plate-like electrode forming the non-circular electron beam passage hole 31 forms an electron lens acting on the electron beam passing through the electron beam passage hole 31 near a position intersecting the horizontal axis X. For this purpose, it has a protruding portion 32 having a large plate thickness. Further, the electron beam passage hole 31
Has a constricted portion 33 that minimizes the horizontal diameter of a region through which the electron beam passes. By applying a dynamically changing voltage higher than the voltage applied to the focus electrode G3 and lower than the voltage applied to the anode electrode G4 to the additional electrode Gs, without impairing the aperture of the main lens, Even stronger astigmatism for controlling the horizontal focusing power and the vertical focusing power can be formed.

In the case of the additional electrode having such a structure, a case has been described in which the voltage applied to the additional electrode is changed in the same manner as described above. Instead of changing the voltage of the additional electrode, [( Similar results can be obtained by changing the value of (applied voltage of additional electrode)-(applied voltage of focus electrode)] / [(applied voltage of anode electrode)-(applied voltage of focus electrode)].

Next, another embodiment of the present invention will be described.

The in-line type color cathode ray tube device of this embodiment has the same configuration as that of the above-described embodiment. Electron gun assembly 7 applied to this color cathode ray tube device
As shown in FIG. 28, is basically configured similarly to the embodiment shown in FIG. In particular, in this embodiment, the additional electrode Gs between the third grid G3 and the fourth grid G4 is a horizontally long non-circular electron beam having a long axis in the horizontal direction (X) as shown in FIG. Passing holes 34B, 3
4G, 34R. Alternatively, the additional electrode Gs
As shown in FIG. 24, a non-circular electron beam passage hole 34 common to three electron beams having a major axis in the horizontal direction may be provided.

The additional electrode Gs is provided in the electron beam passage hole 3
4 (R, G, B) has a protruding portion 35 that is partially thicker at the edge portion. This protrusion 35
Are integrally formed by forming the plate-shaped electrode to be thicker than a predetermined plate thickness. The protrusion 35 is provided symmetrically in the vertical direction in a region where an electron lens that substantially acts on the electron beam is formed.

In the electron gun structure 7 having such a configuration,
The cathode K, the first grid G1, the second grid G2, the third grid G3, and the fourth grid G4 have the first embodiment.
And the same voltage is applied. As shown in FIG. 29, a dynamic focus voltage 50 in which a DC voltage of about 16 kV and an AC component voltage changing in a parabolic manner are superimposed on the additional electrode Gs, as shown in FIG. The AC component voltage is synchronized with the sawtooth deflection current, and rises in a parabolic manner with an increase in the deflection amount of the electron beam.

In this electron gun assembly, when there is no deflection,
The main lens formed between the third grid G3 and the fourth grid G4 has no astigmatism. Therefore, each electron beam is focused with the same focusing force in the horizontal and vertical directions. For this reason, each electron beam is focused on the central portion of the phosphor screen 3 to form a substantially circular beam spot.

At the time of deflection, as the amount of deflection of the electron beam increases, the dynamic focus voltage 40 applied to the third grid G3 increases, and the dynamic focus voltage 50 applied to the additional electrode Gs also increases. Therefore, the value of [(applied voltage of additional electrode) − (applied voltage of third grid)] / [(applied voltage of fourth grid) − (applied voltage of third grid)] is larger than when no deflection is performed. Become.

In this case, since the projection 35 is provided at the edge of each of the additional electrodes Gs where the electron beam passage holes 34 (R, G, B) are formed, the main lens has astigmatism. That is, an aperture lens (quadrupole lens) having a converging action in the horizontal direction and a diverging action in the vertical direction is formed inside the main lens. At the same time, the third grid G3
And the fourth grid G4 have a reduced potential difference. As a result, an effect of reducing the horizontal focusing power and the vertical focusing power of the main lens occurs.

In the electron gun assembly 7, the horizontal focusing force which is increased by the protrusion 35 of the additional electrode Gs and the horizontal focusing force which is weakened by the decrease in the potential difference between the third grid G3 and the fourth grid G4 are reduced. It is configured to be offset.

Thus, similarly to the above-described embodiment, the condition for optimally focusing each electron beam is established in the peripheral portion of the phosphor screen 3 and the main lens is provided with astigmatism. The ellipticity of the beam spot shape of the focused electron beam can be improved, and a substantially circular beam spot can be obtained.

The third grid G3 and the fourth grid G
In the case where the bipotential main lens formed by step 4 is configured as an electron lens whose horizontal focusing power is stronger than the vertical focusing power, the voltage applied to the additional electrode Gs is higher than 16 kV when no deflection is performed. The same effect can be obtained by setting (that is, applying a potential higher than the potential at the geometric center of the main lens to the additional electrode Gs). Further, an AC voltage component that changes in a parabolic manner is superimposed on the third grid G3 during deflection, and [(applied voltage of additional electrode) − (applied voltage of third grid)] / [(applied voltage of fourth grid) − (Applied voltage of the third grid)] is increased as compared with the non-deflection state, and is weakened by the horizontal focusing force that is increased by the effect of the additional electrode and the decrease in the potential difference between the third grid G3 and the fourth grid G4. By configuring so as to cancel the horizontal focusing force, the same effect as in the above-described embodiment can be obtained.

The shape of the thick projection 35 formed on the additional electrode Gs is not limited to the shape shown in FIGS. 23 and 24, but is shown in FIGS. 25 and 26. Such a screen may be formed. Even when the additional electrode Gs having the projection 35 having such a shape is used, the same effect as in the above-described embodiment can be obtained.

Further, as shown in FIG.
The plate-like electrode constituting s is formed by the electron beam passage holes 34 (R,
G, B), at the edges forming the projections 35, the projections 35 are partially thickened, and the electron beam passage holes 34
(R, G, B) may have a constricted portion 36 that minimizes the vertical diameter of the region through which the electron beam passes. That is, the edge of the plate-like electrode forming the constricted portion 36 is formed by the protruding portion 35 formed to be partially thick.

As described above, in the case where the electron beam passage hole formed in the additional electrode Gs is formed in a shape having a thick portion in the vertical direction and a constricted portion in which the electron beam passage hole in the vertical direction is reduced, The effect of the astigmatism that occurs can be further enhanced by the same operation as that of the embodiment.

As described above, the electron gun structure applied to the color cathode ray tube device has the main lens that finally focuses the electron beam on the phosphor screen. The main lens is formed by a focus electrode arranged on the cathode side, an anode electrode arranged on the phosphor screen side, and an additional electrode arranged between the focus electrode and the anode electrode. The additional electrode is located at the geometric center of the main lens. The additional electrode is a plate-like electrode having a predetermined plate thickness and has a non-circular electron beam passage hole. The edge of the plate-like electrode forming the electron beam passage hole is formed so that its horizontal or vertical plate thickness is partially larger than a predetermined plate thickness in a region where an electron lens substantially acting on the electron beam is formed. Have been.

The main lens formed by such a focus electrode, an additional electrode, and an anode electrode has astigmatism that dynamically changes with an increase in the amount of electron beam deflection. This astigmatism increases as the deflection amount of the electron beam increases. The main lens having such astigmatism has a converging action in the horizontal direction and a diverging action in the vertical direction. For this reason, the horizontal collapse of the beam spot in the peripheral portion of the phosphor screen can be reduced. Thus, the beam spot is optimally focused over the entire phosphor screen. Further, it is possible to configure a color cathode ray tube which displays a high quality image by relaxing elliptic distortion of the beam spot.

[0087]

As described above, according to the present invention, an electron beam is focused in an optimum state over the entire surface of a phosphor screen, elliptic distortion of a beam spot is reduced, and an image of good image quality is displayed. Can be provided.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view schematically showing a structure of a color cathode ray tube device according to one embodiment of the present invention.

FIG. 2 is a horizontal sectional view schematically showing a structure of an electron gun assembly applied to the color cathode ray tube device shown in FIG.

FIG. 3 is a perspective view schematically showing a structure of an additional electrode applied to the electron gun assembly shown in FIG. 2;

FIG. 4 is a diagram showing horizontal and vertical electric fields forming a rotationally symmetric bipotential electron lens and a voltage distribution on a central axis of an electron beam passage hole.

5 shows horizontal and vertical directions when an additional electrode is arranged at the geometric center of the electron lens shown in FIG. 4 and a voltage corresponding to the potential of the geometric center is applied to the additional electrode; FIG. 4 is a diagram illustrating an electric field in a direction and a voltage distribution on a central axis of an electron beam passage hole.

FIG. 6 is a diagram showing electric fields in a horizontal direction and a vertical direction when a voltage lower than a potential at a geometric center is applied to the additional electrode shown in FIG. 5, and a voltage distribution on a central axis of an electron beam passage hole; FIG.

FIG. 7 is a view showing the horizontal and vertical directions when the additional electrode shown in FIG. 3 is arranged at the geometric center of the electron lens and a voltage corresponding to the potential at the geometric center is applied to the additional electrode; FIG. 4 is a diagram illustrating an electric field in a direction and a voltage distribution on a central axis of an electron beam passage hole.

FIG. 8 is a view showing the horizontal and vertical directions when the additional electrode shown in FIG. 3 is arranged at the geometric center of the electron lens and a voltage lower than the potential of the geometric center is applied to the additional electrode; FIG. 3 is a diagram showing an electric field of FIG. 1 and a voltage distribution on a central axis of an electron beam passage hole.

FIG. 9 is a view showing the horizontal and vertical directions when the additional electrode shown in FIG. 3 is arranged at the geometric center of the electron lens, and a voltage higher than the potential at the geometric center is applied to the additional electrode; FIG. 3 is a diagram showing an electric field of FIG. 1 and a voltage distribution on a central axis of an electron beam passage hole.

FIG. 10 is a perspective view schematically showing a structure of another additional electrode applied to the electron gun structure shown in FIG. 2;

FIG. 11 is a view showing the horizontal and vertical directions when the additional electrode shown in FIG. 10 is arranged at the geometric center of the electron lens and a voltage lower than the potential of the geometric center is applied to the additional electrode; FIG. 3 is a diagram showing an electric field of FIG.

FIG. 12 is a view showing the horizontal and vertical directions when the additional electrode shown in FIG. 10 is arranged at the geometric center of the electron lens and a voltage higher than the potential at the geometric center is applied to the additional electrode; FIG. 3 is a diagram showing an electric field of FIG.

FIG. 13 is a diagram showing a configuration of an electron gun assembly in a conventional color cathode ray tube device.

FIG. 14A is a diagram showing a shape of a beam spot on a phosphor screen in a conventional self-convergence in-line type color cathode ray tube device,
FIG. 14B is a diagram showing the shape of the beam spot on the phosphor screen when the electron gun assembly is of the BPF ADC & F type.

FIG. 15 (a) is an optical model of a conventional self-convergence in-line type color cathode ray tube device at the time of no deflection, and FIG. 15 (b) is an optical model at the time of deflection.

FIG. 16 is a diagram showing an optical model of an electron gun assembly in which a quadrupole lens is formed inside a main lens.

FIG. 17 is a diagram showing a beam spot shape on a phosphor screen by an electron gun assembly corresponding to the optical model shown in FIG. 16;

FIG. 18 is a horizontal sectional view schematically showing a configuration of an electron gun assembly corresponding to the optical model shown in FIG.

FIG. 19 is a perspective view schematically showing a structure of an additional electrode applied to the electron gun assembly shown in FIG.

FIG. 20 is a diagram showing a relationship between a deflection current applied to a deflection yoke applied to a color cathode ray tube device and a voltage applied to a focus electrode of an electron gun assembly.

FIG. 21 is a view showing a shape of a beam spot on a phosphor screen by the electron gun assembly shown in FIG. 18;

FIG. 22 is a perspective view schematically showing another structure of the additional electrode applied to the electron gun assembly shown in FIG. 2;

FIG. 23 is a perspective view schematically showing a structure of an additional electrode provided in another electron gun assembly applied to the color cathode ray tube device of the present invention.

FIG. 24 is a perspective view schematically showing another structure of an additional electrode provided in another electron gun assembly applied to the color cathode ray tube device of the present invention.

FIG. 25 is a perspective view schematically showing another structure of an additional electrode provided in another electron gun assembly applied to the color cathode ray tube device of the present invention.

FIG. 26 is a perspective view schematically showing another structure of an additional electrode provided in another electron gun assembly applied to the color cathode ray tube device of the present invention.

FIG. 27 is a perspective view schematically showing another structure of an additional electrode provided in another electron gun assembly applied to the color cathode ray tube device of the present invention.

FIG. 28 is a vertical sectional view schematically showing the structure of an electron gun assembly to which the additional electrodes shown in FIGS. 23 to 27 can be applied.

FIG. 29 is a diagram illustrating a relationship between a voltage applied to an additional electrode illustrated in FIG. 28 and a deflection current supplied to a deflection yoke.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 2 ... Funnel 3 ... Phosphor screen 4 ... Shadow mask 5 ... Neck 6 (R, G, B) ... Electron beam 7 ... Electron gun assembly 31 (R, G, B) ... Electron beam passage hole 32 ... Projection Part 33: Constricted part 34 (R, G, B) Electron beam passage hole 35: Projection part 36: Constricted part K (R, G, B) Cathode G1 First grid G2 Second grid G3 Third Grid G4: Fourth grid Gs: Additional electrode

Continuation of the front page (72) Inventor Tsutomu Takekawa 8F, Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 5C041 AA03 AA10 AA14 AB07 AC01 AC05 AC35 AC42 AD02 AD03 AE01

Claims (11)

[Claims] An electron beam generating section for generating an electron beam, and an electron lens section for accelerating an electron beam generated from the electron beam generating section toward a phosphor screen and converging the electron beam on the phosphor screen. A cathode ray tube device comprising: an electron gun assembly; and a deflection yoke that generates a deflection magnetic field that deflects an electron beam emitted from the electron gun assembly in a horizontal direction and a vertical direction of a phosphor screen. At least one electrode to be formed,
A plate-like electrode having a predetermined thickness with an electron beam passage hole, the edge of the plate-like electrode forming the electron beam passage hole, in a region forming an electron lens that substantially acts on the electron beam, A cathode ray tube device wherein the horizontal plate thickness is partially formed to be larger than the predetermined plate thickness. 2. The cathode ray according to claim 1, wherein said electron beam passage hole formed in said plate-shaped electrode has a constricted portion for minimizing a horizontal diameter of a region through which an electron beam passes. Tube equipment. 3. An electron beam generating section for generating an electron beam, and an electron lens section for accelerating the electron beam generated from the electron beam generating section toward the phosphor screen and converging the electron beam on the phosphor screen. A cathode ray tube device comprising: an electron gun assembly; and a deflection yoke that generates a deflection magnetic field that deflects an electron beam emitted from the electron gun assembly in a horizontal direction and a vertical direction of the phosphor screen. At least one electrode to be formed,
A plate-shaped electrode having a predetermined thickness provided with an electron beam passage hole, the edge of the plate-shaped electrode forming the electron beam passage hole, in a region forming an electron lens that substantially acts on the electron beam, A cathode ray tube device characterized in that the plate thickness in the vertical direction is partially thicker than the predetermined plate thickness. 4. The cathode ray according to claim 3, wherein the electron beam passage hole formed in the plate-like electrode has a narrow portion that minimizes a vertical diameter of a region through which the electron beam passes. Tube equipment. 5. An electron beam generator for generating an electron beam, a plurality of electron lens units for accelerating an electron beam generated from the electron beam generator toward a phosphor screen and converging the electron beam on the phosphor screen; An electron gun assembly having
A deflection yoke for generating a deflection magnetic field for deflecting the electron beam emitted from the electron gun assembly in the horizontal and vertical directions of the phosphor screen, wherein at least one of the electron lens units comprises: A focus electrode, an anode electrode, and at least one additional electrode disposed between the focus electrode and the anode electrode, wherein the additional electrode has a plate shape having a predetermined thickness and an electron beam passage hole. An edge portion of the plate-like electrode forming the electron beam passage hole, in a region where an electron lens substantially acting on an electron beam is formed, a horizontal plate thickness thereof is partially equal to the predetermined plate. A cathode ray tube device characterized by being formed thicker than thick. 6. The cathode ray according to claim 5, wherein the electron beam passage hole formed in the plate-like electrode has a narrow portion that minimizes a horizontal diameter of a region through which the electron beam passes. Tube equipment. 7. A voltage higher than the voltage applied to the focus electrode and lower than the voltage applied to the anode electrode is applied to the additional electrode, [(additional electrode voltage) − (focus electrode voltage). ] /
The value of [(anode electrode voltage) − (focus electrode voltage)] changes in synchronization with the deflection of the electron beam by the deflection yoke, and the value decreases as the deflection amount of the electron beam increases. The cathode ray tube device according to claim 5, characterized in that: 8. An electron beam generator for generating an electron beam, a plurality of electron lens units for accelerating an electron beam generated from the electron beam generator toward a phosphor screen and converging the electron beam on the phosphor screen. An electron gun assembly having
A deflection yoke for generating a deflection magnetic field for deflecting the electron beam emitted from the electron gun assembly in the horizontal and vertical directions of the phosphor screen, wherein at least one of the electron lens units comprises: A focus electrode, an anode electrode, and at least one additional electrode disposed between the focus electrode and the anode electrode, wherein the additional electrode has a plate shape having a predetermined thickness and an electron beam passage hole. An edge portion of the plate-like electrode forming the electron beam passage hole, in a region where an electron lens substantially acting on an electron beam is formed, a vertical thickness of the edge portion is partially equal to the predetermined plate. A cathode ray tube device characterized by being formed thicker than thick. 9. The cathode ray according to claim 8, wherein the electron beam passage hole formed in the plate-like electrode has a narrow portion that minimizes a vertical diameter of a region through which the electron beam passes. Tube equipment. 10. A voltage higher than the voltage applied to the focus electrode and lower than the voltage applied to the anode electrode is applied to the additional electrode, [(additional electrode voltage) − (focus electrode voltage). ] /
The value of [(anode electrode voltage) − (focus electrode voltage)] changes in synchronization with the deflection of the electron beam by the deflection yoke, and the value increases as the deflection amount of the electron beam increases. The cathode ray tube device according to claim 8, characterized in that: 11. The electron lens section comprising the focus electrode to the anode electrode, as the deflection amount of the electron beam by the deflection yoke increases, the focusing force in the vertical direction becomes weaker than the focusing force in the horizontal direction. The cathode ray tube device according to claim 5, wherein the cathode ray tube device has a lens function that changes as follows.