JP3038217B2 - Color picture tube equipment - Google Patents

Description

Description: Object of the Invention (Field of Industrial Application) The present invention relates to a color picture tube, and more particularly to a color picture tube device having improved resolution by improving the structure and driving means of an electron gun. .

(Prior Art) At present, the mainstream of the color picture tube is a so-called three-electron gun system.
An in-line type electron gun for emitting an electron beam is used, and the electron beam emitted from the electron gun is applied to a pincushion-like horizontal deflection magnetic field (1) shown in FIG. 11 (a) and a barrel shown in FIG. 11 (b). By deflecting by an asymmetric magnetic field consisting of a vertical deflection magnetic field (2), a three electron beam (3
B), (3G), and (3R) systems that self-converge (self-convergence) have become widespread. Such a self-concentrating type color picture tube device has features that power consumption can be reduced and the quality and performance of the color picture tube can be improved.

However, on the other hand, the non-uniformity of the deflection magnetic field distorts the cross-sectional shape of the electron beam with the deflection angle of the electron beam, and as shown in FIG. 12, the beam spot (5a) at the center of the screen (4) Is a perfect circle, the peripheral beam spot (5b) has an elliptical high-luminance core portion (6) that is long in the horizontal direction (X-axis direction) and a low-luminance halo portion (long vertical direction). 7), and there is a problem that the resolution of the peripheral portion of the screen (4) is significantly deteriorated.

The distortion of the beam spot is caused by the fact that the horizontal focusing magnetic field in the pincushion shape and the vertical deflection magnetic field in the barrel shape weaken the horizontal focusing of the electron beam and conversely increase the vertical focusing.

It is known that the resolution degradation due to such deflection distortion can be reduced by reducing the diameter of the electron beam passing through the main lens of the electron gun and the deflection magnetic field. As has been done, there is a means for strongly focusing an electron beam with a prefocus lens of an electron gun. However, this method has a problem that the beam spot at the center of the screen becomes large because the crossover diameter increases.

As another means, there is a method of reducing deflection distortion by making the prefocus lens an asymmetric lens and making the electron beam incident on the center of the screen underfocus in the vertical direction. However, in this method, the beam spot at the center of the screen becomes an elliptical shape that is long in the vertical direction, and as a result, the resolution of the center of the screen deteriorates.

As still another means, Japanese Patent Application Laid-Open No. 61-39346 discloses an electrode having a non-circular electron beam passing hole whose major axis is a focusing electrode and a non-circular electron beam passing hole whose major axis is a horizontal direction. And an electrode having a quadrupole lens, and a focusing voltage that changes in synchronization with the deflection of the electron beam is applied to one of the electrodes.
Japanese Patent Application Laid-Open No. 61-39347 discloses that a focusing device is divided into two parts, a box-shaped electrode structure including a horizontal position electrode and a vertical position electrode is arranged between the divided electrodes, and one of the electrodes has an electron beam. FIG. 1 shows a configuration in which a focusing voltage that changes in synchronization with the deflection of the focus is applied.

According to these means, a good resolution can be obtained to some extent from the center to the periphery of the screen. However, there are serious problems as follows. That is, for the main lens, the focusing electric field and the diverging electric field are not separated, and the main lens itself cannot be a quadrupole lens. Therefore, in order to obtain a good resolution, it is necessary to provide a quadrupole lens on the cathode side of the main lens. However, this quadrupole lens can be obtained by changing the object point position viewed from the main lens in the horizontal and vertical directions. At the same time, the spread of the electron beam incident on the main lens is also different in the horizontal and vertical directions. The relationship between the object point position and the spread of the electron beam incident on the main lens is to improve the sensitivity (sensitivity) of the peripheral portion of the screen when the focusing voltage is changed in order to weaken the function of the quadrupole lens. Can not. In particular, the problem is that in the case of a large current operation, a large size and a wide deflection angle tube, it is necessary to sufficiently secure the above sensitivity. Therefore, the methods disclosed in these publications can sufficiently improve the resolution of the peripheral portion of the image. Can not.

In Japanese Patent Application Laid-Open No. 64-38947 of the present applicant, a quadrupole lens having different characteristics is provided in a convergence area and a divergence area of a main lens unit, and a constant voltage is applied between the two quadrupole lenses. By providing an intermediate electrode to be applied,
It shows that the resolution of the periphery of the screen is improved by substantially separating the two quadrupole lenses and changing the focusing voltage at the periphery of the screen.

This means is an effective method capable of solving the problems of the above publications and increasing the sensitivity. However, even if this method is applied to a 34-inch class super-large tube, there is a problem that the resolution at the peripheral portion of the screen cannot be sufficiently increased, and higher sensitivity is required.

(Problems to be Solved by the Invention) As described above, there are conventionally various means for reducing the degradation of resolution due to deflection distortion. However, conventional means
This is either a compromise that improves the resolution of the periphery at the expense of the resolution in the center of the screen, or some improvement can be obtained from the center of the screen to the periphery,
It is not enough for large, wide deflection angle tubes,
Furthermore, in order to apply a specific voltage, a special socket or base is required, which causes a problem such as a problem in compatibility.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not use a conventional compromise for resolution, and also has a high resolution over a wide area even for a large-sized and wide-deflection tube. It is an object of the present invention to provide a color picture tube device which can obtain a resolution and has no problem in socket and compatibility.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a focusing electrode, one or a plurality of intermediate electrodes, and a final accelerating electrode from the cathode side. An electron gun is arranged in the order of the final accelerating electrode, and a resistor for dividing a high voltage applied to the final accelerating electrode by resistance and applying a constant voltage to the intermediate electrode is disposed in proximity to the electron gun, In a color picture tube device for deflecting an electron beam emitted from the electron gun by a deflecting magnetic field formed by a deflecting device, the focusing electrode is divided into a plurality of divided focusing electrodes, and at least one of the divided focusing electrodes is provided. Applying a dynamic voltage that varies in synchronization with the deflection of the deflection device, applying a constant voltage to the divided focusing electrode other than the divided focusing electrode to which the dynamic voltage is applied, via the resistor, A first asymmetric focusing electric field having a stronger focusing action in the vertical direction than in the horizontal direction on the intermediate electrode side of the split focusing electrode to which a constant voltage is applied, and the split focusing electrode to which the dynamic voltage is applied. A second asymmetric focusing electric field having a stronger focusing action in the vertical direction than in the horizontal direction is formed between the divided focusing electrodes to which the constant voltage is applied, and is stronger near the final acceleration electrode in the vertical direction than in the horizontal direction. An asymmetric diverging electric field having a diverging action is formed, and when the electron beam is not deflected by the deflecting device, the first and second asymmetric focusing electric fields and the asymmetric diverging electric field are balanced.

Further, a horizontal electric field common to the three electron beams penetrates into the cathode side of the final acceleration electrode and the intermediate electrode side of the divided focusing electrode adjacent to the intermediate electrode.

Further, a constant voltage is applied to the electrodes on both sides of the divided focusing electrode to which the dynamic voltage is applied, and a first voltage is applied to the final acceleration electrode side of the divided focusing electrode to which the dynamic voltage is applied.
, And a second asymmetric focused electric field is formed on the cathode side.

(Operation) For example, if the in-line type electron gun that emits three electron beams is configured as described above, the penetration of the electric field into the focusing electrode adjacent to the intermediate electrode interferes with the penetration from the center and both sides in the horizontal direction. As a result, an asymmetric focusing electric field (first asymmetric focusing electric field) that is relatively weaker than vertical penetration and stronger in the vertical direction than in the horizontal direction is formed. The electric field that permeates the similar final accelerating electrode also becomes an asymmetric divergent electric field (first asymmetric divergent electric field) that is stronger in the vertical direction than in the horizontal direction.

On the other hand, the constant voltage applied to the intermediate electrode is generally higher than the potential corresponding to the position of the intermediate electrode in the case of an electric field expansion lens in which the gap between the electrodes is simply widened (there is no intermediate electrode) from the viewpoint of focus performance. A low voltage is also applied.
Therefore, the asymmetric diverging electric field is stronger between the asymmetric focusing electric field and the asymmetric diverging electric field formed between the focusing electrode and the final acceleration electrode. Further, at least one location between the opposing surfaces of the plurality of divided focusing electrodes is another asymmetric integrated electric field (second asymmetric focusing electric field).
Is formed.

Moreover, since the concentrated electric field on the focusing electrode side and the diverging electric field on the final accelerating electrode side are separated and independent by the intermediate electrode to which a constant voltage is applied, even if the focusing voltage is changed, the diverging electric field has almost no effect. I will not give.

Therefore, at least two asymmetric focusing electric fields and an asymmetric diverging electric field are balanced with respect to the central portion of the screen, so that the electron beam can be focused in a perfect circular shape or a slightly elongated shape. In addition, for the peripheral portion of the screen, the dynamic voltage that rises in synchronization with the deflection of the electron beam weakens the at least two asymmetric focusing electric fields,
The divergent electric field becomes relatively strong as a whole lens. Therefore, it causes the electron beam to undergo a strong divergence in the vertical direction and underfocus in the vertical direction,
Strong focusing in the vertical direction is reduced. In addition, as the dynamic voltage increases, at least two asymmetric focusing electric fields weaken, so that sufficient sensitivity can be obtained.

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 6 shows a color picture tube device according to one embodiment. This color picture tube device has an envelope (12) composed of a panel (10) and a funnel (11) integrally joined to the panel (10).
A phosphor screen (13) comprising a three-color phosphor layer emitting blue, green, and red light is formed, and the phosphor screen (13) is formed.
A jaw mask (14) in which a number of electron beam passage holes are formed is mounted inside the mask. Also,
In the neck (15) of the funnel (11), the following electron gun (16) for emitting three electron beams arranged in parallel on the same horizontal plane is provided. Further, a deflection device (18) is mounted outside the funnel (11).

The deflecting device (18) includes a horizontal deflecting coil that forms a pincushion-shaped horizontal deflecting magnetic field that deflects the electron beam in the horizontal direction, and a vertical deflecting coil that forms a barrel-shaped vertical deflecting magnetic field that deflects in the vertical direction. And 3 emitted from the electron gun (16) by its horizontal and vertical deflection magnetic fields.
The color image is displayed by deflecting the electron beam and scanning the phosphor screen (13) with the three electron beams.

As shown in FIG. 1, the electron gun (16) has heaters (not shown) inserted therein, and the electron guns (16) are arranged in a row in a horizontal direction.
The first to sixth electrodes (21) to (26) are sequentially arranged from the cathode (20) in the direction of the phosphor screen. In particular, in the electron gun (16) of this example, the fifth
The electrode (25) includes three divided focusing electrodes (251) to (253) which are divided and adjacent to each other. Further, the divided focusing electrode (253) located on the phosphor screen side and the sixth electrode (2)
6), two intermediate electrodes (27) and (28) are arranged. These cathode (20), first to sixth electrodes (21)
To (26) and the intermediate electrodes (27) and (28) are integrally fixed by a pair of insulating supports (not shown), and the end surface of the sixth electrode (26) fixed to the phosphor screen side is integrally fixed. Is fitted with a convergence cup (29). Further, a resistor (30) is arranged in the electron gun (16) so as to approach each electrode fixed integrally. This resistor (30) is arranged in the neck together with the electron gun (16).

Among the above electrodes, first and second electrodes (21) and (22)
Consists of thin plate-like electrodes. These electrodes (21), (2)
In 2), three small-diameter circular openings are formed corresponding to the three cathodes (20) arranged in a line. Third electrode (23)
Is formed in a structure in which the open ends of two cup-shaped electrodes abut each other, and the end face on the side of the second electrode (22) has three pieces slightly larger in diameter than the opening of the second electrode (22). The second electrode (22) is formed on the end face on the fourth electrode (24) side.
Three circular openings having a diameter larger than that of the side end surface are formed. The fourth electrode (24) is also formed in a structure in which the open ends of two cup-shaped electrodes abut each other. Fifth electrode (25) -3
Of the divided focusing devices (251) to (253), the divided focusing electrodes (251) and (252) have a structure in which two cup-shaped electrodes are butted at the open end, and the divided focusing electrode (253) is It is formed in a structure in which two cup-shaped electrodes whose open ends are butted together are combined. The intermediate electrodes (27) and (28) are originally composed of thick plate-like electrodes. The sixth electrode (26) is formed in a structure in which the open ends of two cup-shaped electrodes are abutted. Each of the end faces of the fourth electrode (24), the divided focusing electrodes (251) to (253), the sixth electrode (26) and the plate-like intermediate electrodes (27) and (28) has a third electrode ( 23) 4th
Three circular apertures having the same diameter as the aperture on the end face on the electrode (24) side are formed. Further, three circular holes having the same diameter are formed on the bottom surface of the convergence cup (29).

The resistor (30) has one end connected to the sixth electrode (26),
The other end is grounded. An intermediate point (31) is connected to the intermediate electrode (27) via the divided focusing electrode (252) and the divided focusing electrode (252), and the anode voltage (supplied to the anode terminal provided on the side wall of the funnel) The final accelerating voltage is divided by resistance, and the divided focusing electrode (251) and the intermediate electrode (2
A constant voltage is applied to 7), and a constant voltage different from that is applied to the intermediate electrode (28) from the intermediate point (32).

The voltage applied to each electrode is, for example, 15
A DC voltage of about 0 V and an image modulation signal are applied, and the first electrode (21) is grounded. The second electrode (22) is grounded to the fourth electrode (24) in the tube, and a voltage of about 600 V is applied to the third electrode (23).
Is connected to the split focusing electrodes (251) and (253) in the tube,
A dynamic focusing voltage of about 7 kV, which is variable in synchronization with the electron beam deflection, is applied. The sixth electrode (26)
Is applied with a high final accelerating voltage of about 25 to 30 kV, and the split focusing device (252) and the intermediate electrode (27) apply about 40% of the final accelerating voltage applied to the sixth electrode (26). A voltage and about 65% of the final acceleration voltage are applied to the intermediate electrode (28).

By the application of the voltage, a triode portion is formed by the cathode (20) and the first and second electrodes (21) and (22).
A crossover is formed while radiating an electron beam from the substrate. Further, the pre-focusing lens for pre-focusing the electron beam emitted from the triode by the second and third electrodes (22) and (23) is further provided with the split focusing electrodes (251) and
According to (252) and (253), an auxiliary lens for further pre-focusing the electron beam pre-focused by the pre-focus lens is provided by the split focusing electrode (253), the intermediate electrodes (27) and (28), and the second lens. The six electrodes (26) form a main lens that focuses the electron beam on the phosphor screen. The main lens is composed of intermediate electrodes (27) and (28)
, The lens area is expanded, and this is called an extended electric field lens, and constitutes a long focal length lens.

By the way, when the electron gun (16) is configured as described above,
As shown in FIGS. 2A and 2B, the divided focusing electrode (253), the intermediate electrodes (27) and (28) and the sixth electrode (2
In the main lens section formed by 6), the split focusing electrode (2
The horizontal focusing electric field that penetrates into the intermediate electrode (27) side of 53) is formed by the central aperture (34a), the apertures on both sides (34b),
The equipotential line corresponding to (34c) is common. On the other hand, as shown in FIG.
Due to the effect of 5), the radius of the equipotential line in the vertical direction is smaller than that in the horizontal direction, and the focusing effect in the vertical direction is relatively stronger than that in the horizontal direction.

Also, as shown in FIGS. 3A and 3B, the auxiliary lens portion formed by the divided focusing electrodes (251), (252), and (253) also has a relatively vertical focusing action in the horizontal direction. Stronger than the direction.

Similarly, the diverging electric field that penetrates into the sixth electrode (26) of the main lens unit also has a relatively stronger focusing action in the vertical direction than in the horizontal direction.

That is, in the electron gun (16), the lens system is constituted by a combination of two asymmetric focusing electric fields and one asymmetric diverging electric field, and the central part of the phosphor screen is not deflected without deflecting the electron beam. , A predetermined focusing voltage is applied to the divided focusing electrodes (251) and (253). Thereby, the two asymmetric focusing electric fields and the one asymmetric diverging electric field are in an equilibrium state, and the electron beam is focused on the phosphor screen in a perfect circle. In contrast,
When deflecting the electron beam to enter the periphery of the phosphor screen, the focusing voltage applied to the divided focusing electrodes (251) and (253) is increased to increase the divided focusing electrode (252) and the intermediate electrode (27). ) Approach the voltage to be applied. Thereby, the two asymmetric focusing electric fields are weakened, while the asymmetric diverging electric field does not change, so that the asymmetric diverging electric field becomes relatively strong as a whole of the main lens. In addition, since the asymmetry is weakened twice, it becomes largely under-focused in the vertical direction, thereby eliminating the over-focus state received from the deflecting magnetic field, and furthermore, the variable width of the focusing voltage which is changed in synchronization with the deflection of the electron beam. Can be reduced.

The operation of the electron gun (16) is shown by an optical model in FIGS. That is, as shown in FIG.
When the electron beam (36) is not deflected, two relatively weak focusing lenses (37) and (38) and one relatively weak diverging lens (39) are arranged in the horizontal direction. As shown in FIG. 3B, two relatively strong focusing lenses (37) and (38) and one relatively strong diverging lens (39) are formed, and the phosphor is used in both the horizontal and vertical directions. The beam is focused on the screen (13) in the best condition and an almost perfect beam spot is obtained. On the other hand, when the electron beam (36) is deflected, as shown in FIG. 5 (a), in the horizontal direction, the two focusing lenses (37) and (38) allow the focusing voltage to rise even if the focusing voltage increases. Since the sensitivity is low, when the electron beam (36) is not deflected, there is almost no change, and the diverging lens (39)
Also, even if the focusing voltage rises, it does not change because the voltage of the intermediate electrode is constant. On the other hand, in the vertical direction, as shown in FIG. 3B, the two focusing lenses (37) and (38) weaken due to the rise of the focusing voltage, and a large underfocus state occurs in the vertical direction.

Therefore, in the color picture tube device provided with the electron gun (16), the beam spot at the center of the phosphor screen (13) is made almost a perfect circle, and the peripheral portion also has a low brightness of the conventional vertical direction. The halo portion can be almost completely removed, sufficient sensitivity can be obtained even for a large and wide deflection tube, and high resolution can be obtained over the entire screen with a margin. Further, since the voltage to be varied in synchronization with the deflection can be obtained only by superimposing it on the conventional focusing voltage, it can be supplied from the same terminal as the conventional color picture tube. Furthermore, since a voltage is applied to the intermediate electrode (27) via the divided focusing electrode (252), the pattern of the resistor (30) can be directed in a direction in which the potential gradient becomes smooth, and the intermediate electrode (27) ) And (28), the voltage output terminals are effectively separated from each other to improve the withstand voltage characteristics such as discharge in the tube. At the same time, the reliability of the resistor (30) can be improved.

 Next, another embodiment will be described.

In the above embodiment, the electron beam passage hole of each electrode is circular. However, the divided focusing electrode (253) located on the intermediate electrode side, the aperture on the intermediate electrode side of the sixth electrode, and the second asymmetric focused electric field As shown in FIG. 7, the apertures of the multi-divided divided focusing electrodes that form may be non-circular holes (41) whose major axis is in the arrangement direction (horizontal direction) of the three electron beams.

Also, as shown in FIG. 8, two cup-shaped electrodes of the split focusing electrode (253) involved in the formation of two asymmetric focusing electric fields, and the sixth cup-like electrode involved in the formation of the asymmetric diverging electric field.
As for the cup-shaped electrode of the electrode (26), a pair of plate-like members (42) are vertically arranged so as to sandwich three holes inside the cup-shaped electrode, and the horizontal and vertical directions formed between the electrodes are formed. The electric field may be adjusted.

Further, in the above embodiment, the focusing electrode (fifth electrode) is
The division of the focusing electrode is not limited to this, but may be any multiple division of two or more.

Further, the asymmetric focusing electric field may be provided at a plurality of positions of the divided focusing electrode. For example, as shown in FIG. 9, a divided focusing electrode (251), (252) is divided into two, and the divided focusing device (251) located on the fourth electrode (24) side is connected to the third electrode (23). One focused voltage identical to the applied voltage is applied to the other divided voltage by resistance to the divided electrode (252), and a second asymmetric focused electric field is applied between the divided focused electrodes (251) and (252). May be formed.

In the above embodiment, the asymmetric focusing electric field is formed between the divided focusing electrodes. However, the asymmetric electric field formed between the focusing electrodes may be a diverging electric field.

Further, in the above embodiment, the case where the number of the intermediate electrodes is two has been described. However, the number of the intermediate electrodes may be one or three or more.

Further, as for the resistor, as shown in FIG. 10, a variable resistor (43) is installed outside the tube, and the variable resistor (43)
, The other end of the resistor (30) may be grounded so that the focus adjustment of the beam spot in the horizontal direction can be performed independently. With this configuration, focus adjustment can be performed more precisely.

In the above embodiment, the quadra-potential type electron gun has been described. However, the present invention can be applied to other compound type electron guns, and also to a bi-potential type or uni-potential type electron gun. it can. Also,
The present invention is applicable not only to an in-line type electron gun but also to a delta array electron gun. Further, the present invention can be applied to not only an electron gun emitting three electron beams but also an electron gun emitting a plurality of beams and all electron guns emitting a single electron beam.

In the above embodiment, the dynamic focus method in which the focusing voltage is varied in synchronization with the deflection of the electron beam has been described. However, the present invention can be applied to a normal case in which the focusing voltage is fixed and used.

[Effect of the Invention] As described above, the focusing electrode, one or more intermediate electrodes, and the final accelerating electrode are arranged in the order of the focusing electrode, the intermediate electrode, and the final accelerating electrode from the cathode side, and are applied to the final accelerating electrode. A resistor for dividing a high voltage to be applied and applying a constant voltage to the intermediate electrode has an electron gun arranged in close proximity, and an electron beam emitted from this electron gun is deflected by a deflection magnetic field formed by a deflection device. In a color picture tube device that deflects,
The focusing electrode is divided into a plurality of divided focusing electrodes, and a dynamic voltage varying in synchronization with the deflection of the deflecting device is applied to at least one of the divided focusing electrodes, and the divided focusing electrode to which the dynamic voltage is applied is applied. A constant voltage is applied to the divided focusing electrodes other than the above through the resistor, and a first asymmetry having a stronger focusing action in the vertical direction than in the horizontal direction on the intermediate electrode side of the split focusing electrode to which the fixed voltage is applied. Forming a focused electric field, and forming a second asymmetric focused electric field having a stronger focusing action in the vertical direction than in the horizontal direction between the divided focusing electrode to which the dynamic voltage is applied and the divided focusing electrode to which a constant voltage is applied. In the vicinity of the final accelerating electrode, an asymmetric diverging electric field having a stronger diverging action in the vertical direction than in the horizontal direction is formed, and when the electron beam is not deflected by the deflecting device,
When the first and second asymmetric focusing electric fields are balanced with the asymmetric diverging electric field, the focusing voltage that rises in synchronization with the deflection of the electron beam without sacrificing the resolution at the center of the screen. The resolution at the peripheral portion of the screen can be significantly improved with a relatively small increase width. In addition, the number of supply terminals for the focused voltage can be reduced to one as in the related art, and the supply can be performed without the need for a special base or socket, and the compatibility problem can be eliminated.

[Brief description of the drawings]

1 to 10 are explanatory views of an embodiment of the present invention. FIGS. 1 (a) and 1 (b) are a front view and a side view showing a cross section of an electron gun according to the embodiment, respectively. 2 (a) and 2 (b) are a front view and a side view, respectively, showing the equipotential distribution of the main lens portion, and FIGS. 3 (a), 3 (b) show the equipotential distribution of the auxiliary lens portion, respectively. FIGS. 4 (a) and 4 (b) are front and side views, and FIGS. 4 (a) and 4 (b) are optical models for explaining the operation of the electron gun, respectively, in the horizontal and vertical directions when the electron beam is not deflected, and FIG. (A) and (b) are optical models for explaining the operation of the electron gun, respectively, in the horizontal and vertical directions when an electron beam is deflected, and FIG. 6 is a color picture tube according to one embodiment. FIG. 7 shows a divided focusing electrode, a sixth electrode, and FIG. FIG. 8 shows another opening shape of an electrode forming an asymmetric focusing electric field, and FIG. 8 shows another structure of a split focusing electrode forming an asymmetric focusing electric field and a sixth electrode forming an asymmetric diverging electric field. FIG. 9 is a partially cutaway perspective view showing a configuration of an electron gun in which a focusing electrode is divided into two parts.
FIG. 10 is a view of an electron gun having a resistor grounded via a variable resistor, and FIGS. 11 (a) and 11 (b) show a pincushion-like horizontal deflection magnetic field and a barrel-like vertical deflection magnetic field, respectively. Diagram for explaining the effect on
The figure shows the shape of the beam spot on the screen. 16 ... electron gun, 18 ... deflection device, 20 ... cathode 21 ... first electrode, 22 ... second electrode, 23 ... third electrode 24 ... fourth electrode, 25 ... fifth electrode, 251 to 253: split focusing electrode 26: sixth electrode, 30: resistor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-38947 (JP, A) JP-A-59-49142 (JP, A) JP-A-61-42841 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01J 29/56 H01J 29/50

Claims (3)

(57) [Claims] 1. A focusing electrode, one or more intermediate electrodes, and a final accelerating electrode are arranged in this order from the cathode side in the order of the focusing electrode, the intermediate electrode, and the final accelerating electrode, and a high voltage applied to the final accelerating electrode is provided. A resistor for dividing a voltage by resistance and applying a constant voltage to the intermediate electrode has an electron gun arranged in close proximity, and deflects an electron beam emitted from the electron gun by a deflecting magnetic field formed by a deflecting device. In the color picture tube device, the focusing electrode is divided into a plurality of divided focusing electrodes, and a dynamic voltage varying in synchronization with the deflection of the deflecting device is applied to at least one of the divided focusing electrodes. A constant voltage is applied to the divided focusing electrodes other than the divided focusing electrode to which the constant voltage is applied through the resistor. Also forms a first asymmetric focusing electric field having a strong focusing action in the vertical direction, and a vertical direction rather than a horizontal direction between the divided focusing electrode to which the dynamic voltage is applied and the divided focusing electrode to which the constant voltage is applied. A second asymmetric focusing electric field having a strong focusing action is formed, and an asymmetric diverging electric field having a stronger diverging action in the vertical direction than in the horizontal direction is formed near the final accelerating electrode. A color picture tube apparatus wherein the first and second asymmetric focusing electric fields and the asymmetric diverging electric field are balanced when not deflected. 2. A horizontal electric field common to the three electron beams penetrates both the cathode side of the final acceleration electrode and the intermediate electrode side of the divided focusing electrode adjacent to the intermediate electrode. Color picture tube device. 3. A fixed voltage is applied to the electrodes on both sides of the divided focusing electrode to which the dynamic voltage is applied, and a first asymmetric focused electric field and a cathode are provided on the final acceleration electrode side of the divided focusing electrode to which the dynamic voltage is applied. 3. A color picture tube device according to claim 1, wherein a second asymmetric focused electric field is formed on the side.