JPH10162753A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a color picture tube having its less convergence drift due to a potential in a neck inner face. SOLUTION: For this color picture tube, an electronic gun emitting three electronic beams disposed in an array is arranged in a neck 5 of a funnel, and a main lens finally focusing the three electron beams on a phosphor screen by plural electrodes G5, G6 selected from electrodes G1 to G6 of this electron gun is formed. In this case, an opposite part to an opposite electrode of an electrode forming the main lens is constituted by planar electrodes G5p, G6p with their thick place thickness in which threeelectrode-beam through holes 16B, 16G, 16R, 17B, 17G, and 17R are disposed in an array, and a distance from a peripheral rim of en electron beam through hole of this planar electrode to an electrode outer rim in the direction orthogonal to an alignment direction of the electron beam through holes is twice or more as much as an interval of the opposite electrode.

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 having an electron gun which emits three electron beams arranged in a line in the same plane, and more particularly to a color convergence tube by charging an inner wall of a neck provided with the electron gun. The present invention relates to a color picture tube in which fluctuation is prevented.

[0002]

2. Description of the Related Art In general, a color picture tube has an envelope composed of a panel and a funnel-shaped funnel. An electron gun is disposed in a cylindrical neck of the funnel. It is formed in such a structure that a color image is displayed by scanning a phosphor screen composed of a three-color phosphor layer provided on the inner surface of the panel with the beam. Currently, the mainstream of such a color picture tube is an in-line type color picture tube in which an electron beam emitted from an electron gun is a three-electron beam arranged in a line composed of a center beam passing on the same plane and a pair of side beams. Has become.

In general, the above-mentioned electron gun includes a control electrode (first electrode), an accelerating electrode (second electrode), which forms an electron beam generator together with at least three cathodes, and a three-electron beam from the electron beam generator. It has a focusing electrode and a final accelerating electrode that form a main lens that is finally focused on the phosphor screen, and these cathodes and electrodes are integrally supported and fixed by a pair of glass insulating supports. In particular, the focusing electrode and the final accelerating electrode face each other at an interval of about 1 mm.

A voltage obtained by superimposing an image signal on a DC voltage of one hundred and several tens of volts is applied to the cathode of the electron gun, zero volts are applied to the control electrode, several hundred volts are applied to the acceleration electrode, and a final acceleration electrode is applied to the focusing electrode. A voltage of about 20 to 40% of the applied anode high voltage is applied through a stem pin provided on the stem at the neck end. On the other hand, the final accelerating electrode has a valve attached to the inner conductive film coated on the inner surface of the funnel from the anode terminal provided at the large diameter portion of the funnel and the electrode at the tip of the electron gun and pressed against the inner conductive film. The anode high voltage is applied via a spacer or the like.

By applying such a voltage, the cathode,
The above-mentioned electron beam generator is formed by the control electrode and the acceleration electrode, and the above-mentioned main lens is formed by the focusing electrode and the final acceleration electrode.

The inner conductive film is applied from the large diameter portion of the funnel to the inner surface of the neck facing the intermediate portion of the tip electrode of the electron gun, and the inner conductive surface of the neck facing the intermediate portion of the tip electrode. From the direction of the stem. As a result, when an anode high voltage is applied to the inner conductive film, the inner surface of the neck on which the inner conductive film is not formed is gradually charged, and the inner potential of the neck increases. Then, the inner surface potential of the neck penetrates between the opposing electrodes of the electron gun and changes the trajectory of the electron beam.

[0007] The penetration of the inner surface potential of the neck between the opposing electrodes of the electron gun penetrates from the entire periphery of the inner surface of the cylindrical neck. The Coulomb force received from the inner surface potential is balanced and almost no orbital change occurs. On the other hand, as for the side beam, in the direction orthogonal to the arrangement direction of the three electron beams, the inner surface of the neck is located symmetrically, so the Coulomb force received from the direction orthogonal to the arrangement direction of the three electron beams is balanced, and the orbital change is Rarely happen. However, in the arrangement direction of the three electron beams, the position of the inner surface of the neck is asymmetric, so that the trajectory changes.

That is, the three electron beams emitted from the electron gun in a single line do not change the trajectory of the center beam even if the inner surface potential of the neck penetrates between the electrodes of the electron gun, but the trajectory of the pair of side beams does not change. Change, causing convergence drift.

In addition, the change in the trajectory of the electron beam due to the penetration of the inner surface potential of the neck is largest between the electrodes forming the main lens closest to the inner conductive film and having the widest electrode interval.

As a means for solving the convergence drift caused by the penetration of the inner surface potential of the neck, it is conceivable to reduce the electrode interval of the electron gun.
It cannot be made very small in terms of withstand voltage, and is not an effective means.

As another means, it is conceivable to increase the outer diameter of the electrodes of the electron gun so as to make it difficult for the inner surface potential of the neck to penetrate between the electrodes. In this case, an insulating method for integrally supporting and fixing the electrodes together with the cathodes is considered. Due to the restrictions on the inner diameter of the support and the neck, there is a limit in increasing the outer diameter, and it cannot be increased until a sufficient effect is obtained.

[0012]

As described above, the conventional in-line type color picture tube has a problem that the trajectory of the pair of side beams changes due to the charging of the inner surface of the neck, causing convergence drift.

As means for solving the convergence drift, if the electrode spacing of the electron gun is reduced, the withstand voltage becomes a problem. Even if the outer diameter of the electrode of the electron gun is increased to make it difficult for the inner surface potential of the neck to penetrate between the electrodes, a sufficient effect is obtained due to the restriction of the insulating support that integrally supports and fixes the electrode together with the cathode and the inner diameter of the neck. However, there is a problem that the size cannot be increased until is obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a color picture tube with less convergence drift due to the potential on the inner surface of the neck.

[0015]

An electron gun which emits three electron beams arranged in a line composed of a center beam and a pair of side beams passing on the same plane is disposed in a neck of a funnel. A color picture tube having a plurality of electrodes arranged in the direction of the phosphor screen and forming a main lens for finally focusing three electron beams on the phosphor screen by the plurality of electrodes selected from these electrodes , An opposed portion of the electrode forming the main lens and the opposed electrode is constituted by a thick plate-like electrode in which three electron beam passage holes through which three electron beams individually pass are formed in a line, The distance from the peripheral edge of the electron beam passage hole of the plate-shaped electrode to the outer edge of the electrode in a direction orthogonal to the arrangement direction of the electron beam passage holes was set to be at least twice as large as the distance from the counter electrode.

Further, the distance from the periphery of the electron beam passage hole of the plate electrode to the outer edge of the electrode in the direction orthogonal to the arrangement direction of the electron beam passage holes is set closer to the pair of side beam passage holes than near the center beam passage hole. Was made larger.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a color picture tube which is one embodiment of the present invention. This color picture tube has an envelope composed of a panel 1 and a funnel 2 having a funnel shape. On the inner surface of the panel 1, a phosphor screen 3 composed of a three-color phosphor layer that emits blue, green and red light is provided. A shadow mask 4 is provided inside the phosphor screen 3 so as to face the phosphor screen 3. On the other hand, in the neck 5 of the funnel 2, a center beam 6G and a pair of side beams 6B passing on the same horizontal plane are provided.
, 6R, three electron beams 6B, 6G,
An electron gun 7 for emitting 6R, which will be described later, is provided. An anode terminal 9 is formed on the large-diameter portion 8 of the funnel 2, and an inner conductive film 10 is further formed from the inner surface of the large-diameter portion 8 to the inner surface of the adjacent portion of the neck 5. The three electron beams 6B, 6G, and 6R emitted from the electron gun 7 are horizontally and vertically deflected by a deflecting device 12 mounted outside the boundary between the large diameter portion 8 of the funnel 2 and the neck 5. The screen is formed to display a color image by horizontally and vertically scanning the phosphor screen 3 while being deflected by a magnetic field.

As shown in FIG. 1, the electron gun 7 includes three cathodes K arranged in a row in the horizontal direction (X-axis direction).
B, KG, KR, three heaters H for individually heating these cathodes KB, KG, KR, and the cathodes KB, KG
, KR and a first electrode G1 (control electrode) and a second electrode G2, which are arranged at predetermined intervals in the direction of the phosphor screen.
(Acceleration electrode), third electrode G3, fourth electrode G4, fifth electrode G5 (focusing electrode), sixth electrode G6 (final acceleration electrode), and a shield attached to the end of the phosphor screen of the sixth electrode G6. The heater H, the cathodes KB, KG, KR and the first to sixth electrodes G1 to G are provided.
6 are integrally supported and fixed by a pair of glass insulating supports 14.

Each of the first and second electrodes G1, G2 is an elliptical plate-like electrode having a major axis in the horizontal direction (X-axis direction). Each of the third and fourth electrodes G3 and G4 is an elliptical cylindrical electrode having a major axis extending in the horizontal direction and abutting two cup-shaped electrodes. The fifth and sixth electrodes G5 and G6 have an elliptical cylindrical electrode having a major axis in the horizontal direction where two cup-shaped electrodes are abutted, and a major axis in the horizontal direction attached to one end of these cylindrical electrodes. Oval thick plate-like electrode G5p,
G6P and these plate-like electrodes G5p, G6P
Are disposed at the opposing portions of the fifth electrode G5 and the sixth electrode G6, respectively.

In the first and second electrodes G1 and G2, three small circular electron beam passage holes having a diameter of 1 mm or less correspond to the three cathodes KB, KG and KR arranged in a line. Is formed. On the second electrode G2 side of the third electrode G3, circular electron beam passage holes having a diameter of about 2 mm larger than the opening of the second electrode G2 are arranged in a row corresponding to the three cathodes KB, KG and KR. Is formed. Third
The fourth electrode G4 side of the electrode G3, the fourth electrode G4, the fifth electrode G5
In the sixth electrode G6 and the shield cup SC, large circular electron beam passage holes having a diameter of about 4 to 6 mm are formed in a line.

In particular, in the electron gun 7, the plate electrode G5
p and G6P are the electron beam passage holes 16B, 16G and 16R.
, 17B, 17G, 17R from the periphery of these electron beam passage holes 16B, 16G, 16R, 17B, 17G, 1
The distance d to the outer edge of the electrode in the vertical direction (Y-axis direction) perpendicular to the arrangement direction (horizontal direction) of the 7R is at least twice the distance between the fifth electrode G5 and the sixth electrode G6. Moreover, as shown in FIG. 2 (illustrated with respect to the plate electrode G5p), the electron beam passage holes 16B, 16G, 16R, 17B, 17G, 17R.
The outer edges of the electrodes in the vertical direction perpendicular to the arrangement direction of the electrodes project around the pair of side beam passage holes 16B, 16R, 17B, 17R, and form a pair of side beam passage holes 16B, 16R.
, 17B, 17R, the outer diameter in the vertical direction is large, and the electron beam passage holes 16B, 16G, 16R, 1
The distance from the periphery of 7B, 17G, 17R to the outer edge of the electrode in a direction orthogonal to the arrangement direction is closer to the pair of side beam passage holes 16B, 16R, 17B, 17R than to the vicinity of center beam passage holes 16G, 17B. Is getting bigger.

In this electron gun 7, three cathodes KB,
A voltage obtained by superimposing an image signal on a DC voltage of about 150 V is applied to KG and KR, the first electrode G1 is grounded, the second electrode G2 is about 800 V, and the third electrode G3 is about 6 to 9 kV.
Is applied. The fourth electrode G4 is connected to the second electrode G2 and has a voltage of about 800 V. The fifth electrode G5 is connected to the third electrode G3 and has a voltage of about 6 to 9 kV.
An anode voltage of about 30 kV is applied to 6. The cathodes KB, KG, KR and the first to fifth electrodes G1 to G5
Is applied via a stem pin 19 provided on the stem 18 at the end of the neck 5, while the anode voltage applied to the sixth electrode G6 is the anode voltage provided on the large diameter portion of the funnel. The terminal, the inner conductive film 10 coated on the inner surface of the funnel, and the valve spacer 20 which is attached to the shield cup Sc and presses against the inner conductive film 10 are supplied.

By applying such a voltage, the cathode K
B, KG, KR and first and second electrodes G1, G2 control electron emission from each of the cathodes KB, KG, KR and generate and emit an electron beam by focusing and accelerating the emitted electrons to form an electron beam. The second and third electrodes G2 and G3 form a prefocus lens for prefocusing the electron beam from the electron beam generator. The third, fourth and fifth electrodes G3, G4, G5 form a sub-lens for further pre-focusing the electron beam pre-focused by the pre-focus lens. Further, the fifth and sixth electrodes G5 and G6 form a main lens for finally focusing the electron beam prefocused by the sub-lens on the phosphor screen.

By the way, the fifth and sixth lenses forming the main lens
When the opposing portions of the electrodes G5 and G6 are formed as described above, the influence of the neck potential penetrating between the fifth and sixth electrodes G5 and G6 on the three electron beams 6B, 6G and 6R is reduced, and the pair of side electrodes is used. By reducing the orbital change caused by the asymmetrical effect of the neck potential on the beams 6B and 6R,
The convergence drift of the three electron beams 6B, 6G, 6R can be greatly reduced.

That is, when an anode voltage is supplied to the inner conductive film 10 applied to the inner surface of the funnel 2, the inner conductive film 10 on the stem 18 side is formed from the end of the inner conductive film 10 on the neck 5 side. The inner surface of the neck 5 which is not charged is charged, but the potential of the inner surface of the neck due to the charging changes with time, and it takes time until it is stabilized. Moreover, the reproducibility of the stable potential is unstable and not constant.

The neck inner surface potential penetrates between the electrodes forming each electron lens of the electron gun 7 to change the trajectory of the pair of side beams 6B and 6R. In particular, a pair of side beams 6B and 6B in which the penetration of the inner surface potential of the neck is asymmetric.
This causes a change in the horizontal trajectory of R. In addition, the influence of the neck inner surface potential is caused by the fifth and sixth electrodes G5, G5, which form the main lens having the widest electrode interval and being close to the inner conductive film 10.
It is largest between G6. Since the penetration of the neck inner surface potential between the electrodes penetrates from the entire inner surface of the neck 5, as shown in FIG. 4, for example, the horizontal component 21H of the electric field 21 due to the oblique neck inner surface potential is also reduced to the side. Involved in beam trajectory changes. The change in the trajectory of the side beam due to the penetration of the neck inner surface potential from this oblique direction is as follows:
It is considered that about half of the total change in the trajectory of the side beam due to the inner surface potential of the neck.

Therefore, the outer edges of the vertical electrodes near the side beam passage holes 16B, 16R, 17B, 17R of the plate-like electrodes G5p, G6P forming the opposing portions of the fifth and sixth electrodes G5, G6 forming the main lens. When the diameter in the vertical direction is increased, the electric field 21 due to the inner surface potential of the neck from the oblique direction is less likely to penetrate between the fifth and sixth electrodes G5 and G6, and the orbital change of the pair of side beams 6B and 6R is reduced. It can be significantly reduced.

That is, the fifth and sixth elements forming the main lens
Plate-shaped electrodes G5p, G6P constituting opposing portions of the electrodes G5, G6
, A pair of side beam passage holes 16B, 16R, 17B,
If the vertical outer diameter near 17R is increased as shown in FIG. 5A with respect to the conventional size shown in FIG.
The neck inner surface potential 22 that penetrates between the fifth and sixth electrodes G5 and G6 moves away by Δe (illustrated with respect to the side beam passage holes 16R and 17R) according to the difference in the magnitude, and affects the side beam. Can not be.

It has been calculated by calculation that the effect of the electric field due to the inner surface potential of the neck on the electron beam (side beam) substantially extends to about twice the electrode interval. Therefore, the fifth and sixth electrodes G5 forming the main lens as described above
, G6, the electron beam passage holes 16B, 16G, 16R, 17B, 17 of the plate-shaped electrodes G5p, G6P.
Electron beam passage holes 16B, 16G from the periphery of G, 17R
, 16R, 17B, 17G, 17R, by setting the distance to the electrode periphery in the vertical direction perpendicular to the arrangement direction to be at least twice the distance between the fifth electrode G5 and the sixth electrode G6, the inner surface of the neck from an oblique direction. The penetration of the potential is caused by the side beam 6B,
The influence on 6R can be almost eliminated, and the change in orbit of the side beams 6B and 6R can be greatly reduced.

As described above, the fifth and sixth electrodes G5, G
When the plate-like electrodes G5p, G6P constituting the opposed portion of FIG. 6 are formed to protrude in the vertical direction in the vicinity of the pair of side beam passage holes 16B, 16R, 17B, 17R, an insulating member for integrally supporting and fixing the electrodes. Since the support 14 is disposed in the direction perpendicular to the center beam passage hole 16G, the electrodes can be integrally supported and fixed while maintaining the conventional positional relationship and dimensions between the insulating support 14 and the electrodes.

In the electron gun shown in FIG. 1, the vertical direction near the pair of side beam passage holes of the plate-like electrode forming the facing portion of the fifth and sixth electrodes forming the main lens is integrally extended. The plate-like electrodes constituting the opposing portions of the fifth and sixth electrodes are almost the same as the plate-like electrodes G5p and G6P as shown in FIG. 6A for the plate-like electrodes G5p. An overhang 24 having a thickness or, as shown in FIG. 2B, an overhang 24 having a small thickness bent in an L-shape is separately formed, and these overhangs 24 are formed by the side beams of the plate electrodes G5p and G6P. The structure may be welded to the vertical electrode side wall near the through holes 16B, 16R, 17B, 17R.

Further, in the electron gun shown in FIG. 1, the vertical directions near the pair of side beam passage holes of the plate-like electrode forming the opposed portions of the fifth and sixth electrodes forming the main lens are respectively extended. However, as shown in FIG. 7, one of the plate-like electrodes G5p and G6P constituting the facing portion of the fifth and sixth electrodes G5 and G6 forming the main lens is located near a pair of side beam passage holes. The fifth and sixth electrodes G can be extended only in the vertical direction.
5, the penetration of the neck inner surface potential between G6 and G6 can be reduced, and the orbital change of the pair of side beams due to the penetration of the neck inner surface potential can be reduced.

In the above embodiment, the case where the basic structure of the electron gun is a QPF (Quadra Potential FOCUS) type has been described. However, the present invention can be applied to a color picture tube having an electron gun having a different basic structure. .

[0035]

According to the present invention, an electron gun which emits three electron beams arranged in a line composed of a center beam and a pair of side beams passing on the same plane is disposed in the neck of the funnel. The main lens is formed in a color picture tube which forms a main lens for finally focusing three electron beams on the phosphor screen by a plurality of electrodes selected from these electrodes. The portion of the electrode that faces the counter electrode is made up of a thick plate-like electrode in which three electron beam passage holes through which three electron beams individually pass are formed in a row, and the electron of the plate-like electrode is formed. The distance from the peripheral edge of the beam passage hole to the outer edge of the electrode in a direction orthogonal to the arrangement direction of the electron beam passage holes is set to be at least twice the distance between the counter electrode,
When the distance from the periphery of the electron beam passage hole of the plate-shaped electrode to the outer edge of the electrode in the direction orthogonal to the arrangement direction of the electron beam passage holes is made larger near the pair of side beam passage holes than near the center beam passage hole. With a simple structure, the convergence drift of three electron beams due to the inner surface potential of the neck can be greatly reduced, and a color picture tube with good characteristics can be obtained.

[Brief description of the drawings]

FIG. 1A is a horizontal sectional view showing a configuration of an electron gun of a color picture tube according to an embodiment of the present invention, and FIG.
(B) is a vertical sectional view.

FIG. 2 is a diagram showing a configuration of a plate-like electrode constituting a facing portion of fifth and sixth electrodes forming a main lens of the electron gun.

FIG. 3 is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining penetration of a neck inner surface potential between electrodes of an electron gun.

FIG. 5A is an explanatory diagram of a neck inner surface potential penetrating between fifth and sixth electrodes according to an embodiment of the present invention;
FIG. 5B shows fifth and sixth conventional structures shown for comparison.
It is explanatory drawing of the neck inner surface potential which penetrates between electrodes.

6 (a) and 6 (b) show a fifth and a sixth, respectively.
It is a figure which shows the different structure of the plate-shaped electrode which comprises the opposing part of an electrode.

7A is a horizontal sectional view showing a different configuration of an electron gun of a color picture tube according to an embodiment of the present invention, and FIG. 7B is a vertical sectional view.

[Explanation of symbols]

 2: Funnel 3: Phosphor screen 5: Neck 6B, 6R: A pair of side beams 6G: Center beam 7: Electron gun 10: Inner conductive film 16B, 16R: A pair of side beam passage holes 16G: Center beam passage hole 17B, 17R ... a pair of side beam passage holes 17G ... center beam passage hole 22 ... neck inner surface potential 24 ... overhang portion G1 ... first electrode G2 ... second electrode G3 ... third electrode G4 ... fourth electrode G5 ... fifth electrode G6 ... Sixth electrode G5p: plate electrode G6p: plate electrode KB, KG, KR: cathode

Claims (2)

[Claims] 1. An electron gun which emits three electron beams arranged in a line consisting of a center beam and a pair of side beams passing on the same plane in a neck of a funnel is provided. A color picture tube having a plurality of electrodes arranged in a color picture tube forming a main lens that finally focuses the three electron beams on a phosphor screen with the plurality of electrodes selected from the plurality of electrodes; The facing portion of the electrode forming the lens and the facing electrode is formed of a thick plate-like electrode in which three electron beam passage holes through which the three electron beams individually pass are formed in a line. The distance from the peripheral edge of the electron beam passage hole of the electrode to the outer edge of the electrode in a direction orthogonal to the arrangement direction of the electron beam passage hole is at least twice as large as the distance from the counter electrode. The color picture tube according to features. 2. The distance from the periphery of the electron beam passage hole of the plate-shaped electrode to the outer edge of the electrode in a direction orthogonal to the arrangement direction of the electron beam passage holes is closer to the pair of side beam passage holes than to the vicinity of the center beam passage hole. 2. The color picture tube according to claim 1, wherein is larger.