JPH09237587A - Color picture tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube device which ca provide high resolu tion in a while area of a fluorescent material screen surface, by eliminating necessity for using a resistor is high resonator for generating focus voltage by dividing of anode voltage, and for supplying from the outside voltages two kinds of focus. SOLUTION: Cathodes 1a, 1b, 1c control electrode 2, acceleration electrode 3, first focusing electrode 4, second focusing electrode 22 and a final acceleration electrode 23 are successively arranged, and a voltage applying means 36 applying dynamic voltage, increased in accordance with increasing deflection angle of an electron beam, to the second focusing electrode 22 and a resistor 7 connected between the first/second focusing electrodes 4. 22 are provided. In an opposed surface of the second focusing electrode 22 and the final acceleration electrode 23, oblong electron beam passing holes 24a, 24b, 24c, 25a, 25b, 25c are respectively formed in a vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube device configured so that a high resolution can be obtained over the entire surface of a phosphor screen.

[0002]

2. Description of the Related Art In a color picture tube device, a so-called self-convergence method is widely used in order to concentrate three electron beams impinging on each phosphor emitting red, green and blue on the entire phosphor screen surface. Has been done. In this self-convergence type color picture tube device, if the optimum focus voltage is obtained so that a beam spot with a small diameter and a perfect circle can be obtained at the center of the phosphor screen surface, the horizontal beam spot will be produced at the periphery of the phosphor screen surface. The optimum focus state is maintained but the vertical direction is overfocused, and as a result, it becomes difficult to obtain a good beam spot and resolution in the peripheral portion. As a method for solving this problem and maintaining the optimum focus state in the horizontal direction and the vertical direction over the entire phosphor screen surface, the following method has been conventionally used.

As a conventional example 1, Japanese Patent Laid-Open No. 1-232643
Is described in Japanese Patent Application Publication No. In this conventional example, as shown in FIG. 15, a resistor 7 of about 200 kΩ is connected between the first focusing electrode 4 and the second focusing electrode 5, and the dynamic focus becomes higher as the deflection angle of the electron beam increases. A voltage is applied to the second focusing electrode 5.

As a conventional example 2, for example, Japanese Patent Laid-Open No. 7-67
There is one described in Japanese Patent Publication No. 09. In this conventional example,
A reference voltage is obtained by dividing the anode voltage by a high-resistance resistor arranged inside the tube, and only the dynamic focus voltage, which increases as the deflection angle of the electron beam increases, is supplied from outside the tube.

As a conventional example 3, for example, Japanese Patent Application Laid-Open No. 61-9
There is one described in Japanese Patent No. 9249. In this conventional example, a quadrupole lens electric field in which the focusing action in the horizontal direction and the diverging action in the vertical direction become stronger as the deflection angle of the electron beam increases, and the focusing action becomes weaker as the deflection angle of the electron beam increases. A main lens electric field is formed.

An electron lens system formed by this electron gun configuration is equivalently shown by an optical lens, as shown in FIGS.
It looks like 8. FIG. 16 shows an electron lens system formed when only the reference focus voltage Vc is applied to the second focusing electrode, that is, when the dynamic voltage Vp is not superimposed. FIG. 18 shows a dynamic focus voltage V obtained by superimposing the dynamic voltage Vp on the reference focus voltage Vc.
It is an electron lens system formed when d is applied to the second focusing electrode. In each figure, (a) is a horizontal lens configuration in the center of the phosphor screen surface, (b) is a vertical lens configuration in the center of the phosphor screen surface,
(A ') shows a horizontal lens configuration in the peripheral portion of the phosphor screen surface, and (b') shows a vertical lens configuration in the peripheral portion of the phosphor screen surface.

As shown in FIG. 16, the dynamic voltage V
When a constant reference focus voltage Vc that does not superimpose p is applied, the action of the diverging lens 13 in the horizontal direction and the action of the focusing lens 14 in the vertical direction occur at the peripheral portion of the phosphor screen surface 12 due to the deflection magnetic field. The distance between the phosphor screen surface 12 and the main lens 11 is large in the peripheral portion of the phosphor screen surface 12, but is corrected by the action of the diverging lens 13 in the horizontal direction due to the deflection magnetic field. Become. That is, in the horizontal direction, the optimum focus state is maintained over the entire phosphor screen surface. On the other hand, in the vertical direction, in addition to the distance between the phosphor screen surface 12 and the main lens portion 11 becoming large, the action of the converging lens 14 of the deflection magnetic field causes an overfocus state in the peripheral portion of the phosphor screen surface 12. In this case, the beam spot on the phosphor screen surface 12 has a vertically long shape with halos 15 in the vertical direction, that is, above and below the beam spot, as shown in FIG.

As shown in FIG. 18, the dynamic voltage V
When the dynamic focus voltage Vd superposed with p is applied to the second focusing electrode, the beam spot can maintain the optimum focus both in the horizontal and vertical directions. As shown in FIG. 19, the beam spot has a small diameter and is close to a perfect circle. Can be obtained. The reason will be described below.

In the electron gun structure as shown in FIG. 15, the second
When the dynamic focus voltage Vd is applied to the focusing electrode 5, a substantially constant potential Vd1 lower than the peak value of the dynamic focus voltage Vd and higher than the reference focus voltage Vc is generated on the first focusing electrode 4 as shown in FIG. . Therefore, in the peripheral portion of the phosphor screen surface 12, the potential Vd1 of the first focusing electrode 4 is equal to the potential Vd of the second focusing electrode 5.
It becomes lower than d. In addition, three vertically long non-circular electron beam passage holes are provided on the end face of the first focusing electrode 4 on the side of the second focusing electrode 5, and 3 elongate non-circular electron beam passage holes are provided on the end face of the second focusing electrode 5 on the first focusing electrode 4 side. Two horizontally long non-circular electron beam passage holes are provided.

With these configurations, an electric field between the first focusing electrode 4 and the second focusing electrode 5 becomes the action of the focusing lens 20 in the horizontal direction and the action of the diverging lens 21 in the vertical direction, as shown in FIG. A lens, the so-called quadrupole lens electric field, is formed. Further, the intensity of the main lens electric field 17 formed between the second focusing electrode 5 and the final accelerating electrode 6 due to the dynamic focus voltage Vd applied to the second focusing electrode 5 becomes weaker as the deflection angle of the electron beam increases. Become.

Therefore, the action of the main lens electric field 17 weakened in the horizontal direction around the phosphor screen surface 12 and the action of the focusing lens 20 of the quadrupole lens electric field cancel each other out, so that the optimum focus state is maintained. On the other hand, the overfocus state is corrected by the action of the weakened main lens electric field 17 in the vertical direction and the action of the divergent lens 21 of the quadrupole lens electric field, and it is possible to maintain the optimum focus state also in the vertical direction. In this manner, a beam spot having a small diameter and a shape close to a perfect circle can be obtained at the peripheral portion of the phosphor screen surface, and high resolution can be realized.

[0012]

However, in the above-mentioned conventional example 1, the dynamic focus voltage whose voltage increases as the deflection angle of the electron beam increases and the reference focus which is constant regardless of the deflection angle of the electron beam. It is necessary to supply two types of focus voltages, namely voltage.
This reference focus voltage is almost equal to the dynamic focus voltage when the deflection angle is zero, that is, at the center of the phosphor screen surface.

Further, in Conventional Example 2, the anode voltage is 25 kV to
It is a high voltage of 30 kV, and it is necessary to use a resistor of several GΩ (giga ohm) or more in order to suppress the power consumption of the resistor that divides such a high voltage. Such a high resistance resistor is expensive, and it is difficult to secure reliability regarding electrical characteristics and breakdown voltage.

Further, in the conventional example 3, as shown in FIG. 5, points at which the dynamic focus voltage Vd applied to the second focusing electrode has a peak are a and a ', and the potential Vd1 of the first focusing electrode is When bd and b ′ are coincident with Vd, the potential Vd1 generated at the first focusing electrode is lower than Vd between ab and b′-a ′, but Vd1 is reduced between bb ′. It becomes higher than Vd. As shown in FIGS. 18A and 18B, b− including the center of the phosphor screen
The quadrupole lens electric field formed between the first focusing electrode and the second focusing electrode between b ′ produces the action of the diverging lens 18 in the horizontal direction and the action of the focusing lens 19 in the vertical direction. Therefore, the beam spot is slightly underfocused in the horizontal direction and slightly overfocused in the vertical direction. Therefore, as shown in FIG. 20, the beam spot near the center of the phosphor screen surface has a shape that is slightly crushed up and down from the perfect circle, causing a deviation from the optimum focus state.

Furthermore, the smoothing resistance used in Conventional Example 3 is about 200 kΩ, and it cannot be said that the impedance due to the interelectrode capacitance is sufficiently large to be ignored. As a result, the quadrupole lens electric field is not completely formed. Therefore, also due to this factor, the beam spot near the central portion of the phosphor screen surface is deviated from the optimum focus state in both the horizontal direction and the vertical direction, and it is difficult to obtain high resolution over the entire phosphor screen surface.

The present invention has been made in view of the above-mentioned conventional problems.
It is not necessary to use a high-resistance resistor for generating a focus voltage by dividing the anode voltage, and it is not necessary to supply two kinds of focus voltages from the outside, and a high resolution can be obtained over the entire phosphor screen surface. An object is to provide a color picture tube device that can be obtained.

[0017]

SUMMARY OF THE INVENTION A color picture tube apparatus according to the present invention comprises three cathodes, a control electrode, an accelerating electrode, a first focusing electrode, a second focusing electrode, and a final accelerating electrode, which are horizontally arranged inline. And an electrode group in which
A voltage applying unit that applies a dynamic focus voltage having a higher voltage as the deflection angle of the electron beam increases to the second focusing electrode; and a resistor connected between the first focusing electrode and the second focusing electrode. When the potential of the second focusing electrode is higher than the potential of the first focusing electrode, a quadrupole electric field between the first focusing electrode and the second focusing electrode has a focusing action in the horizontal direction and a diverging action in the vertical direction. When the quadrupole electric field lens forming means forming a lens and the first focusing electrode and the second focusing electrode have the same potential, a combined focusing action of a plurality of electric field lenses formed from the cathode to the final accelerating electrode. Is provided in the horizontal direction rather than in the vertical direction.

It is preferable that the electric field lens correcting means is composed of an electron beam passage hole which is formed in the facing surface of each of the second focusing electrode and the final accelerating electrode and which is long in the vertical direction. Alternatively, it may be constituted by an electron beam passage hole formed in the control electrode and extending in the vertical direction.

According to the above structure, the voltage is applied to the second focusing electrode according to the ratio of the capacitance between the acceleration electrode and the first focusing electrode and the capacitance between the first and second focusing electrodes. A substantially DC potential smaller than the peak value of the dynamic focus voltage is generated at the first focusing electrode. As a result, a potential difference is generated between the first focusing electrode and the second focusing electrode with an increase in the deflection angle of the electron beam, and the focusing action is horizontal and the diverging action is vertical between the first focusing electrode and the second focusing electrode. A quadrupole lens electric field is formed. Further, the focusing action of the main lens electric field formed between the second focusing electrode to which the dynamic focus voltage is applied and the final accelerating electrode is weakened as the deflection angle increases. The quadrupole lens electric field and the main lens electric field correct the vertical overfocus state due to the deflection magnetic field, so that the optimum focus state can be maintained in both the horizontal and vertical directions on the entire phosphor screen surface.

Further, when the first focusing electrode and the second focusing electrode have the same potential, the combined focusing action of the electric field lens formed by the electron gun is stronger in the horizontal direction than in the vertical direction. Divergence in the horizontal direction formed between the first focusing electrode and the second focusing electrode occurring in the center of the surface,
A quadrupole lens electric field that has a focusing action in the vertical direction is given by, for example,
It can be canceled by the strong horizontal focusing action and the weak vertical focusing action of the main lens field.

In order to obtain the quadrupole lens electric field having the above-mentioned action, it is desirable that the potential generated on the first focusing electrode is a constant potential, and the potential generated on the first focusing electrode is electrostatic between the acceleration electrode and the first focusing electrode. It is determined by the capacitance and the ratio of the capacitances of the first focusing electrode and the second focusing electrode. Therefore, it is preferable to connect the accelerating electrode and the first focusing electrode with a capacitance element.

Further, the quadrupole field lens forming means includes a substantially rectangular electron beam passage hole vertically elongated in the plate surface of the first focusing electrode on the side of the second focusing electrode, and the second focusing electrode. And a substantially rectangular electron beam passage hole elongated in the horizontal direction formed on the plate surface of the electrode on the side of the first focusing electrode,
At least one of the facing plate surfaces of the first focusing electrode and the second focusing electrode has a partition portion that stands up from the vicinity of the long side of the electron beam passage hole of the plate surface and projects toward the other plate surface side. Preferred structure. Thereby, the electrostatic capacitance between the first focusing electrode and the second focusing electrode forming the quadrupole lens can be suppressed to be small. Instead of the partition section, a structure may be adopted in which a square tube section that projects toward the other plate surface is provided so as to surround the electron beam passage hole.

At least one of the resistor and the capacitance element may be arranged outside the picture tube. As a result, it is possible to avoid the possibility that the vacuum degree of the picture tube is lowered due to the gas release of the resistor or the capacitance element. Specifically, in the outer pin of the stem portion that closes the neck end of the picture tube, a structure in which a resistor is connected between the connecting pin for the first focusing electrode and the connecting pin for the second focusing electrode is preferable.

Alternatively, in the socket portion connected to the outer pin of the stem portion for closing the neck end portion of the picture tube,
The resistor may be connected between the first focusing electrode terminal and the second focusing electrode terminal. Alternatively, in the base portion interposed between the outer pin of the stem portion closing the neck end portion of the picture tube and the socket portion connected thereto, the contact hole of the first focusing electrode connecting pin and the second focusing electrode. The resistor paste may be applied between the contact holes of the connection pins for use.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a color picture tube device to which the present invention is applied has an envelope 8 composed of a panel and a funnel, and blue, green, and red phosphors are applied to the inner surface of the panel. A phosphor screen surface 9 is formed. The electron gun 10 is housed inside the neck portion of the envelope 8 that faces the phosphor screen surface 9.

(Embodiment 1) As shown in FIG. 2, three cathodes 1a, 1b, 1c arranged horizontally, a control electrode 2, an acceleration electrode 3, a first focusing electrode 4, and a second focusing electrode. Two
2 and the final acceleration electrode 23 constitute an electron gun of an in-line type color picture tube device. First focusing electrode 4
Has three vertically elongated electron beam passage holes on the end face on the second focusing electrode 22 side. Further, the second focusing electrode 22 has three horizontally long (longitudinal to the horizontal direction) end faces on the first focusing electrode 4 side.
The non-circular electron beam passage hole is formed on the final accelerating electrode 23 side, and three vertically elongated (longitudinal in the vertical direction) non-circular electron beam passage holes are formed. Further, three vertically elongated non-circular electron beam passage holes are formed on the end surface of the final acceleration electrode 23 on the second focusing electrode 22 side. Further, three circular electron beam passage holes are formed on the end faces of the control electrode 2, the acceleration electrode 3, and the first focusing electrode 4 on the acceleration electrode 3 side.

As an example of the first embodiment, the hole diameter of the electron beam passage hole of each electrode and the electrode plate thickness are determined as follows. That is, the diameter of the round hole provided in the control electrode is 0.3 to 0.7 mm, and the electrode plate thickness is 0.05 to 0.09 m.
m, the accelerating electrode has a hole diameter of 0.3 to 0.7 mm, and an electrode plate thickness of 0.
2 to 0.5 mm, and the hole diameter of the first focusing electrode on the acceleration electrode side was 0.7 to 1.2 mm. Further, the electron beam passage hole of the first focusing electrode 4 on the second focusing electrode 22 side and the non-circular electron beam passage hole of the second focusing electrode 22 on the first focusing electrode 4 side both have a long side length of 4. 5mm, short side length 3.6m
m rectangular holes, and the distance between both electrodes was 0.7 mm.

Typical values of the DC potential applied to each electrode during operation are as follows: the cathodes 1a to 1c are 50 to 150V,
The control electrode 2 is 0 V, the acceleration electrode 3 is 300 to 700 V, and the final acceleration electrode 23 (Va) is 25 to 30 kV. Second
Voltage is applied to the focusing electrode by the voltage applying means 36. This dynamic focus voltage Vd is a voltage obtained by superimposing a dynamic voltage Vp that changes in a parabolic shape in synchronization with the deflection of the electron beam on a reference focus voltage Vc of about 20 to 35% of the voltage Va applied to the final acceleration electrode. And has a waveform as shown in FIG. The peak interval of this dynamic focus voltage waveform is one horizontal scanning period 1H.
The point where the dynamic focus voltage Vd becomes the reference focus voltage Vc is the point where the horizontal deflection angle becomes zero. Further, the first focusing electrode 4 is connected to the second focusing electrode 22 via the resistor 7 as shown in FIG. The resistor 7 is arranged inside the envelope 8.

In the electron gun having the above-mentioned structure, a capacitance (C23) is formed between the facing surfaces of the acceleration electrode 3 and the first focusing electrode 4, and between the facing surfaces of the first focusing electrode 4 and the second focusing electrode 22. Also, a capacitance (C34) is formed. as a result,
A circuit by capacitive coupling as shown by an equivalent circuit in FIG. 4 is formed. The first focusing electrode 4 is electrically coupled to the accelerating electrode 3 via the capacitance C23. In one embodiment, the capacitances C23 and C34 are a few pF. When the resistance value R of the resistor 7 is sufficiently large, for example, about 10 MΩ, the first focusing electrode 4 has a value smaller than the peak voltage of the dynamic focus voltage Vd and larger than the reference focus voltage Vc as shown in FIG. An almost constant voltage Vd1 is generated. Although it depends on the values of the electrostatic capacitances C23 and C34 and the value of the horizontal deflection frequency, if the resistance value R of the resistor 7 is 5 MΩ or more, Vd1 becomes a substantially constant voltage.

In the present embodiment, the deviation from the optimum focus state in the vicinity of the central portion of the phosphor screen surface is made difficult to occur as follows. As shown in FIG. 2, in the electron gun of the color picture tube device according to the present embodiment, the electron beam passage holes 24a, 24b, 24c and the final holes of the end surface of the second focusing electrode 22 on the final acceleration electrode 23 side and the final Acceleration electrode 23
Electron beam passage hole 25 on the end surface of the second focusing electrode 22 side
A, 25b, and 25c are non-circular (elliptical) holes that are long in the vertical direction. Further, in one embodiment, the electron beam passage hole of the first focusing electrode 4 on the second focusing electrode 22 side and the electron beam passage hole of the second focusing electrode 22 on the first focusing electrode 4 side are both in the long side direction. It is a rectangular hole with a length of 4.5 mm and a length of 3.6 mm in the short side direction, and the distance between both electrodes is 0.7.
mm, and the ratio of the major axis to the minor axis of the electron beam passage holes on the final accelerating electrode 23 side of the second focusing electrode 22 and on the second accelerating electrode 22 side of the final accelerating electrode 23 is 1.1 to.
It was set to 1.4.

FIG. 6 is an equivalent view of an electron lens system in the above electron gun configuration with an optical lens system. In FIG. 6, (a) is a horizontal lens configuration in the center of the phosphor screen surface, (b) is a vertical lens configuration in the center of the phosphor screen surface, (a ′)
Shows a horizontal lens structure in the peripheral part of the phosphor screen surface, and (b ′) shows a vertical lens structure in the peripheral part of the phosphor screen surface. When the dynamic focus voltage shown in FIG. 3 is applied to the second focusing electrode 22, the substantially constant potential Vd1 shown in FIG. 5 is generated at the first focusing electrode 4. Therefore, the phosphor screen surface 12
At the center, the potential Vd of the second focusing electrode 22 is lower than the potential Vd1 of the first focusing electrode 4.

Therefore, the quadrupole lens electric field formed between the first focusing electrode 4 and the second focusing electrode 22 causes the action of the diverging lens 30 in the horizontal direction and the action of the focusing lens 31 in the vertical direction. On the other hand, the second focusing electrode 22 and the final accelerating electrode 2
3, a main lens electric field is formed in which the action of the vertical focusing lens 27 is weaker than that of the horizontal focusing lens 26. This is the final acceleration electrode 23 of the second focusing electrode 22.
This is because the electron beam passage holes on the side of the second focusing electrode 22 of the side and the final accelerating electrode 23 are vertically long in the vertical direction. This point is different from the above-mentioned conventional example 3. The action of the divergent lens 30 in the horizontal direction of the quadrupole lens electric field and the action of the focusing lens 31 in the vertical direction are canceled by the action of the strong focusing lens 26 in the horizontal direction of the main lens electric field and the action of the weak focusing lens 27 in the vertical direction, and the beam spot Can maintain the optimum focus state in both horizontal and vertical directions.

On the other hand, in the peripheral portion of the phosphor screen surface 12, the action of the diverging lens 13 in the horizontal direction and the action of the focusing lens 14 in the vertical direction occur due to the deflection magnetic field. Since the potential of the second focusing electrode becomes higher than the potential of the first focusing electrode, the action of the focusing lens 32 in the horizontal direction and the action of the diverging lens 33 in the vertical direction are between the first focusing electrode 4 and the second focusing electrode 22. A quadrupole lens electric field that acts is generated. Further, the potential of the second focusing electrode increases as the deflection angle of the electron beam increases, so that the focusing lens 2 for the electric field of the main lens 2
The actions of Nos. 8 and 29 are weakened as the deflection angle increases.

The distance between the phosphor screen surface 12 and the main lens is larger in the peripheral portion than in the central portion of the phosphor screen surface 12, but this distance difference is corrected by the action of the diverging lens 13 in the horizontal direction due to the deflection magnetic field. . The action of the converging lens 14 on the deflection field generated in the vertical direction is the action of the diverging lens 33 on the quadrupole lens field and the action of the weakened main lens field 2
The beam spots are offset by 9, and the beam spot is in the optimum focus state in both the horizontal and vertical directions. In this way, the beam spot can be kept in the optimum focus state from the central portion to the peripheral portion of the phosphor screen, and as a result, a beam spot with a small diameter and a nearly perfect circle can be obtained over the entire phosphor screen surface.

When the first focusing electrode and the second focusing electrode are at the same potential, as the electric field lens correction means for strengthening the combined focusing action of the plurality of electric field lenses formed by the electron gun in the horizontal direction rather than in the vertical direction, In the present embodiment, the vertically long electron beam passage holes are provided on the facing surfaces of the second focusing electrode and the final accelerating electrode, respectively, but the present invention is not limited to this and other specific configurations may be adopted. For example, center gun (G) and side gun (R,
The present invention is applied to the main lens for overlapping the lens electric field of B) or the main lens in which the electric field in the tube axis direction of the electron gun is expanded to strengthen the synthetic focusing action of a plurality of electric field lenses in the horizontal direction than in the vertical direction. You can also

Further, instead of making the focusing action of the main lens stronger in the horizontal direction than in the vertical direction, for example, JP-A-55-21
As in the cathode ray tube device described in JP-A-832, JP-A-55-141051, or JP-A-59-111237, the end faces of the control electrode, the acceleration electrode, and the first focusing electrode on the acceleration electrode side. A structure in which a non-circular electron beam passage hole is provided in at least one of them may be adopted. For example, the control electrode is provided with a vertically long non-circular electron beam passage hole, specifically, a rectangular electron beam passage hole having a horizontal direction of 0.3 mm and a vertical direction of 0.4 mm.

In this case, since the horizontal hole diameter is small,
Since the operating area of the cathode becomes smaller and the current density becomes larger, the object point becomes smaller, and at the same time, the cathode lens works strongly, so that the position of the object point can be near the cathode. on the other hand,
Since the hole diameter is large in the vertical direction, the object point becomes large and, at the same time, the object point moves away from the cathode. That is, the electric field lens action in the horizontal direction becomes stronger than that in the vertical direction due to the positional difference of the object points generated in the vertical electron beam passage hole of the control electrode.

At this time, the focusing action of the prefocus becomes strong in the horizontal direction and the electron beam is narrowed down, and the electron beam spreads in the vertical direction. Therefore, a slit-shaped plate can be attached to the first focusing electrode side of the acceleration electrode. preferable. As a result of suppressing the spread of the electron beam in the vertical direction by the slit-shaped plate, the combined focusing action of the plurality of electric field lenses formed by the electron gun is likely to be stronger in the horizontal direction than in the vertical direction.

(Embodiment 2) In Embodiment 1 described above,
As shown in FIG. 5, when the dynamic focus voltage Vd is applied to the second focusing electrode, the potential of the first focusing electrode becomes a substantially constant potential Vd1 smaller than the peak value of Vd and larger than the reference focus voltage Vc. The potential Vd1 generated at the first focusing electrode is preferably a constant DC potential. The magnitude of the AC component superimposed on Vd1 is influenced by the electrostatic capacitance C23 between the acceleration electrode and the first focusing electrode, and the larger the value of the electrostatic capacitance C23, the smaller the AC component.
On the other hand, the capacitance C between the first focusing electrode and the second focusing electrode
The smaller 34 is, the smaller the magnitude of the AC component superimposed on Vd1 is. The capacitance between the electrodes largely depends on the shape of the facing electrodes, that is, the facing area and the distance between the electrodes. However, the capacitance between such electrodes is typically a few pF. Since the electrode shape is designed so as to obtain the necessary characteristics of the electric field lens formed between the electrodes, it is difficult to increase the capacitance between the electrodes to about several hundred pF.

The second embodiment is the same as the first embodiment described above.
The AC component of the potential generated at the focusing electrode is reduced, and its electron gun structure is as shown in FIG. The acceleration electrode 3 and the first focusing electrode 4 are connected via a capacitance element 35 (capacitance Co) provided inside the envelope.
Other electrode structures, applied voltage, etc. are the same as those in the first embodiment. In one example, the capacitance Co of the capacitance element 35 was 150 pF.

An equivalent circuit formed by the electron gun structure as described above is shown in FIG. Since the electrostatic capacitance Co is connected in parallel with the electrostatic capacitance C23 between the acceleration electrode 3 and the first focusing electrode 4, the electrostatic capacitance between the acceleration electrode 3 and the first focusing electrode 4 is effective. It has increased. In this case, the potential Vd1 generated on the first focusing electrode 4 is a DC voltage that is almost constant as shown in FIG. 9, and Vd1 in the first embodiment.
It can be seen that the AC component is smaller than that of No. 1 (FIG. 5). Therefore, a slight deviation from the optimum focus state of the beam spot due to the AC component of the potential generated at the first focusing electrode 4 is reduced.

(Third Embodiment) In the third embodiment, in order to suppress the AC component of the potential generated at the first focusing electrode, C
An electrode structure in which 34 is reduced is provided. As shown in FIG. 10A, a partition 37 is provided on the long side of the electron beam passage hole on the end surface of the first focusing electrode 4 on the second focusing electrode 22 side.
As shown in (b), a partition 37 is provided on the long side of the electron beam passage hole on the end surface of the second focusing electrode 22 on the first focusing electrode 4 side. By providing the partition 37, the quadrupole lens electric field formed between the facing surfaces of the first focusing electrode 4 and the second focusing electrode 22 becomes strong unless the distance between the facing surfaces changes.

This quadrupole lens action depends on the synergistic action of the shape of the electron beam passage hole itself and the partition. That is, by providing the partitions 37 and widening the distance between the facing surfaces, a quadrupole lens electric field having the same strength as the quadrupole lens electric field in the case where the partitions 37 are not provided can be obtained, and the first focusing electrode 4 and The capacitance C34 between the second focusing electrode 22 and the second focusing electrode 22 can be reduced. Therefore, the AC component generated in the first focusing electrode can be reduced.

Also, as shown in FIG. 11, when the rectangular tube portion 39 is provided around the electron beam passage hole 38 on the facing surface of the first focusing electrode 4 and the second focusing electrode 22, as in the case of FIG. The same effect can be obtained. Further, the quadrupole lens may be formed in a structure in which the electron beam passage hole is a round hole and a partition or a square tube is provided around the hole.

(Embodiment 4) In the above-described embodiment, a resistor connected between the first focusing electrode and the second focusing electrode, or a resistor connected between the acceleration electrode and the first focusing electrode. A capacitance element was provided inside the picture tube. However, for example, the case of using the resistor using carbon as a conductive _{material, CO, C 2 H 4,} C 3 H 6, CO 2, C 4 H 6 or the like is generated from the resistor, reduction in the degree of vacuum tube May cause For a vacuum device such as a color picture tube, the gas emitted from the resistor or the capacitance element tends to shorten the product life. In particular, the closer the cathode of the color picture tube is to the cathode of the electron gun, the greater the influence of the released gas, and the higher the possibility of shortening the life of the color picture tube.

Therefore, in the fourth embodiment, by disposing the resistor or the capacitance element outside the picture tube, the vacuum degree of the picture tube is lowered due to the gas release of the resistor or the capacitance element. Avoid the fear. Specifically, in the stem portion or the socket portion that closes the end portion of the picture tube neck in which the plurality of electrical connection pins are arranged in a circle, a resistor is provided between the first focusing electrode terminal and the second focusing electrode terminal. Connect. Alternatively, the resistor paste is applied between the contact hole of the first focusing electrode pin and the contact hole of the second focusing electrode pin in the base portion interposed between the stem portion and the socket portion.

In FIG. 12, a resistor 7 is connected between the connecting pin for the first focusing electrode and the connecting pin for the second focusing electrode on the outer pin 44 side of the stem portion 43 for closing the neck end portion of the picture tube. Here is an example: FIG. 13 shows an example in which the resistor 7 is connected between the first focusing electrode terminal and the second focusing electrode terminal of the socket portion 40 connected to the outer pin 44 of the stem portion 43. Further, FIG. 14 shows a base portion 41 interposed between the stem portion 43 of the picture tube and the socket portion 40.
An example in which the resistor paste 42 is applied between the contact hole of the first focusing electrode pin and the contact hole of the second focusing electrode pin on the stem side of FIG. After applying the resistor paste, the base portion 41 is fixed to the stem 43 with an insulating adhesive material. An example of the resistor paste is a ruthenium oxide paste.

The present invention is not limited to an electron gun in which one quadrupole lens electric field is formed between the accelerating electrode and the final accelerating electrode, but an electron gun in which a plurality of quadrupole lens electric fields are formed, For example, it can be applied to a color picture tube having an electron gun described in JP-A-3-93135 or JP-A-3-95835.

The electron guns described in these publications are
First and second auxiliary electrodes are provided between the acceleration electrode and the first focusing electrode, the first auxiliary electrode and the first focusing electrode are connected by a conductive wire, and the second auxiliary electrode and the second focusing electrode are connected. Are connected by a conductor. In this case, the location where the resistor is connected is not limited to between the first focusing electrode and the second focusing electrode,
It may be connected between the auxiliary electrode and the second focusing electrode, or may be connected between the first auxiliary electrode and the second auxiliary electrode.

The present invention can also be applied to a color picture tube equipped with an electron gun having one or more electrodes between the acceleration electrode and the first focusing electrode. As a specific example, two electrodes are provided between the accelerating electrode and the first focusing electrode, and the electrode on the cathode side of these electrodes has the same potential as the first focusing electrode, and the other electrode has the same potential as the accelerating electrode. To do. And, for example, the first
And a resistor is connected between the second focusing electrode and the second focusing electrode. As a result,
Since the electrostatic capacitance C23 between the acceleration electrode and the first focusing electrode is increased, the AC component of the potential generated in the first focusing electrode is reduced, and the shift from the optimal focus state is reduced.

[0051]

As described above, according to the color picture tube device of the present invention, it is not necessary to use a high resistance resistor for generating a focus voltage by dividing the anode voltage, and two types of There is no need to supply the focus voltage externally, that is, by simply supplying the dynamic focus voltage, it is possible to maintain the beam spot in the optimum focus state over the entire phosphor screen surface, thereby achieving high resolution over the entire screen. It

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an entire color picture tube device to which the present invention is applied.

FIG. 2 is a perspective view showing a structure of an electron gun of the color picture tube device according to the first embodiment of the present invention.

3 is a waveform diagram of a dynamic focus voltage applied to a second focusing electrode of the electron gun of FIG.

4 is an equivalent circuit diagram of the electron gun of FIG.

5 is a diagram showing a potential change waveform generated in the first focusing electrode of the electron gun of FIG.

FIG. 6 is a diagram showing horizontal and vertical electron lens models at a central portion and a peripheral portion of a phosphor screen when a dynamic voltage is applied in the electron gun of FIG.

FIG. 7 is a configuration diagram of an electron gun of a color picture tube device according to a second embodiment of the present invention.

8 is an equivalent circuit diagram of the electron gun of FIG.

9 is a diagram showing a potential change waveform generated in the first focusing electrode of the electron gun of FIG. 7.

FIG. 10 (a) is a perspective view of a first focusing electrode device having a partition for suppressing the electrostatic capacitance between the first and second focusing electrodes, and (b) the electrostatic capacitance between the first and second focusing electrodes. Perspective view of a second focusing electrode device having a partition for restraining

FIG. 11 (a) is a perspective view of a first focusing electrode device having a rectangular tube portion for suppressing the electrostatic capacitance between the first and second focusing electrodes. FIG. 11 (b) is an electrostatic diagram between the first and second focusing electrodes. FIG. 3 is a perspective view of a second focusing electrode device having a rectangular tube portion for suppressing the capacity.

FIG. 12 is a side view showing a structure in which a resistor connected between the first focusing electrode and the second focusing electrode is provided on the outer pin of the stem portion of the color picture tube device.

FIG. 13 is a perspective view showing a structure in which a resistor connected between the first focusing electrode and the second focusing electrode is provided in the socket portion of the color picture tube device.

FIG. 14 is a perspective view showing a structure in which a resistor connected between the first focusing electrode and the second focusing electrode is provided in the base portion of the color picture tube device.

FIG. 15 is a configuration diagram of an electron gun of a conventional color picture tube device.

16 is a diagram showing electron lens models in the horizontal and vertical directions in the central portion and the peripheral portion of the phosphor screen when the dynamic voltage is not superimposed on the focus voltage in the electron gun of FIG.

17 is a diagram showing the shape of a beam spot in the peripheral portion of the phosphor screen when the dynamic voltage is not superimposed on the focus voltage in the electron gun of FIG.

18 is a diagram showing horizontal and vertical electron lens models in the central portion and the peripheral portion of the phosphor screen when a dynamic voltage is superimposed on the focus voltage in the electron gun of FIG.

FIG. 19 is a diagram showing the shape of a beam spot around the phosphor screen when a dynamic voltage is superimposed on the focus voltage in the electron gun of FIG. 15.

20 is a diagram showing the shape of a beam spot at the center of the phosphor screen when a dynamic voltage is applied to the focus voltage in the electron gun of FIG.

[Explanation of symbols]

1a, 1b, 1c cathode 2 control electrode 3 acceleration electrode 4 first focusing electrode 7 resistor 8 envelope 9 phosphor screen 10 electron gun 22 second focusing electrode 23 final accelerating electrode 24a, 24b, 24c of the second focusing electrode Electron beam passage hole on final accelerating electrode side 25a, 25b, 25c Electron beam passage hole on second focusing electrode side of final accelerating electrode 35 Capacitive element 36 Voltage applying means 37 Partition portion 38 Electron beam passing hole 39 Square tube portion 40 Socket part 41 Base part 42 Resistor paste 43 Stem part 44 Outer pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Sukeno 1-1 Sachimachi, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd.

Claims (11)

[Claims] 1. An electrode group in which three cathodes, a control electrode, an accelerating electrode, a first focusing electrode, a second focusing electrode, and a final accelerating electrode, which are arranged inline in the horizontal direction, are arranged in order, and an electron beam A voltage applying unit that applies a dynamic focus voltage having a higher voltage as the deflection angle increases to the second focusing electrode; a resistor connected between the first focusing electrode and the second focusing electrode; When the potential of the focusing electrode is higher than the potential of the first focusing electrode, a quadrupole field lens is formed between the first focusing electrode and the second focusing electrode that has a focusing action in the horizontal direction and a diverging action in the vertical direction. When the first focusing electrode and the second focusing electrode are at the same potential, the composite focusing action of the plurality of electric field lenses formed from the cathode to the final accelerating electrode is performed. And it has a color picture tube apparatus comprising a field lens correcting means for stronger than a straight direction in the horizontal direction. 2. The color picture tube according to claim 1, wherein said electric field lens correction means comprises a vertically elongated electron beam passage hole formed in the facing surface of each of said second focusing electrode and said final accelerating electrode. apparatus. 3. A color picture tube device according to claim 1, wherein said electric field lens correction means is composed of a vertically elongated electron beam passage hole formed in the control electrode. 4. The color picture tube device according to claim 1, wherein the acceleration electrode and the first focusing electrode are connected by a capacitance element. 5. The quadrupole field lens forming means includes a substantially rectangular electron beam passage hole vertically elongated in the plate surface of the first focusing electrode on the side of the second focusing electrode, and the second focusing. And a substantially rectangular electron beam passage hole that is long in the horizontal direction and is formed on the plate surface of the electrode on the side of the first focusing electrode.
At least one of the facing plate surfaces of the focusing electrode and the second focusing electrode has a partition portion that stands up from the vicinity of the long side of the electron beam passage hole on the plate surface and projects toward the other plate surface side. The color picture tube device according to any one of claims 1 to 4. 6. The quadrupole electric field lens forming means includes an electron beam passage hole, which is formed in a plate surface of the first focusing electrode on the side of the second focusing electrode and is substantially rectangular in the vertical direction, and the second focusing. And a substantially rectangular electron beam passage hole that is long in the horizontal direction and is formed on the plate surface of the electrode on the side of the first focusing electrode.
At least one of the facing plate surfaces of the focusing electrode and the second focusing electrode has a rectangular tube portion protruding toward the other plate surface so as to surround the electron beam passage hole of the plate surface. 4. The color picture tube device according to claim 4. 7. The color picture tube device according to claim 1, wherein the resistor is arranged outside the picture tube. 8. The color picture tube device according to claim 4, wherein the capacitance element is arranged outside the picture tube. 9. A resistor is connected between the connecting pin for the first focusing electrode and the connecting pin for the second focusing electrode in the outer pin of the stem portion that closes the neck end of the picture tube. Color picture tube device. 10. A socket portion connected to an outer pin of a stem portion for closing a neck end portion of a picture tube, wherein the resistor is connected between the first focusing electrode terminal and the second focusing electrode terminal. The color picture tube device according to claim 7. 11. A contact hole and a second focusing hole for a first focusing electrode connecting pin in a base portion interposed between an outer pin of a stem portion for closing a neck end portion of a picture tube and a socket portion connected thereto. 8. The color picture tube device according to claim 7, wherein the resistor paste is applied between the electrode connection pin and the contact hole.