JPH09245661A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit center and side electron beams to readily match in the sensitivity for correcting astigmatism. SOLUTION: This cathode-ray tube has, for each of the electron beams of a first focusing electrode 4, a pair of vertical electrodes 41 installed and for a second focusing electrode 5 a pair of horizontal electrodes 51 installed which extend toward the first focusing electrode from a direction perpendicular to the direction of alignment of the electron beams in such a way as to sandwich each electron beam; a voltage that varies with the deflection angle of the electron beam is applied to the second focusing electrode 5, the pair of horizontal electrodes 51 are shaped so that they are asymmetrical on each side of a portion corresponding to the center of the path of a side beam, and the area on the side of a center beam across the center of the path of the side beam is made larger, at least near the center of the path of the side beam, than the outside area opposite to the center beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and in particular, it is equipped with an electron gun which emits three electron beams arranged in one direction toward a screen and is capable of obtaining high resolution on the entire screen. Color cathode ray tube.

[0002]

2. Description of the Related Art The resolution that influences the image quality of a color television picture tube or a color display tube largely depends on the electron beam spot diameter and its shape on the screen constituting the fluorescent screen.

That is, high resolution cannot be obtained unless the electron beam spot, which is a bright spot generated on the screen by the electron beam impact, is small in diameter and close to a perfect circle.

However, since the trajectory of the electron beam from the electron gun to the screen becomes longer toward the periphery of the screen as the deflection angle of the electron beam increases, an electron beam spot with a small diameter and a perfect circle is obtained at the center of the screen. Even if the focus voltage is maintained at an optimum value, it is impossible to obtain a good electron beam spot and a high resolution around the spot.

Therefore, as the deflection angle of the electron beam increases, the focus voltage is increased, and the electric field of the main lens is reduced.
So-called dynamic focus method is adopted,
When this method is applied to an in-line type color cathode ray tube having an electron gun which emits three electron beams arranged in one horizontal direction, there are problems as described below.

That is, in order to obtain a self-convergence effect, an in-line type color cathode ray tube in which three electron beam emitting portions are arranged on a straight line in the horizontal direction has a horizontal deflection magnetic field in a pincushion shape and a vertical deflection magnetic field in a barrel. Since the electron beams are respectively distorted in the same shape, the cross-sectional shape of the electron beam that has passed through the deflection magnetic field is distorted into a non-circular shape.

[0007] The screen surface is usually rectangular in shape, that is, its side is long, that is, the side in the electron beam arrangement direction (horizontal direction) is long.

FIG. 10 is a schematic diagram showing the relationship between the horizontal deflection magnetic field of the pincushion magnetic field distribution and the deflection of the electron beam, and FIG.
Is an explanatory view of a screen-like electron beam spot shape, where B (Bs, Bc, Bs) is an electron beam, H is a horizontal direction, V is a vertical direction, B _H is a horizontal deflection magnetic field, and B _H1 is a bipolar magnetic field. A component, B _H2 is a quadrupole magnetic field component, B _C is a high brightness part (core part), and B _L is a low brightness part (haze part).

As shown in FIG. 10A, the three electron beams B (Bs, Bc, Bs) are deflected in the direction of arrow H by passing through a pincushion-shaped horizontal deflection magnetic field _BH. . The pincushion magnetic field is considered to be composed of a dipole magnetic field component shown in FIG. 4B and a quadrupole magnetic field component shown in FIG. 4C. The quadrupole magnetic field component gives a self-convergence effect. Regarding the beam, a diverging effect is given in the horizontal direction and a focusing effect is given in the vertical direction, and the electron beam B has a horizontally long flat cross section in the horizontal direction.

The diverging action acts in such a direction as to cancel the overfocus of the electron beam spot due to an increase in the electron beam trajectory with an increase in the deflection angle of the electron beam. Therefore, in the in-line type color cathode ray tube, the electron beam spot In the horizontal direction, the optimal focus state is maintained during the deflection period. However, in the vertical direction, the degree of overfocus is significantly increased by the addition of the focusing action.

As a result, the electron beam spots formed in the central portion of the spot are circular as shown by B in FIG. 11A, while the electron beam spots formed in the peripheral portion in the horizontal direction are high. It is distorted into a non-circular shape composed of the brightness portion B _C and the low brightness portion _BL, and particularly the large extension of the low brightness portion _{BL in} the vertical direction adversely affects the focus characteristics.

In such a case, when the conventional dynamic focus method is applied, the dynamic focus method uniformly weakens the lens action of the main lens regardless of the horizontal direction and the vertical direction. Even if B _L is removed, the horizontal direction, which is already in the optimum focus, is in an underfocus state, and the diameter in the horizontal direction increases.

As a result, the diameter of the electron beam spot becomes extremely long horizontally, and the resolution in the horizontal direction decreases.

Japanese Patent Laid-Open No. 63-32837 discloses a color cathode ray tube which solves such a problem and can obtain high resolution over the entire screen.

FIG. 12 is a perspective view for explaining the structure of the electron gun in the conventional color cathode ray tube disclosed in the above publication.

In the figure, three cathodes 1a, 1b and 1c arranged in a straight line in the horizontal direction are a control electrode 2, an acceleration electrode 3, a first focusing electrode 4, a second focusing electrode 5 and a final acceleration electrode (anode). ) 6 and constitutes an in-line type electron gun.

The first focusing electrode 4 has three circular electron beam passage holes on the surface facing the second focusing electrode 5, and four vertical electrodes sandwiching each of these electron beam passage holes from the horizontal direction. Has 41. The second focusing electrode 5 has three circular electron beam passage holes on the surface facing the first focusing electrode 4 and two vertical electrodes 51 sandwiching these electron beam passage holes from the vertical direction. are doing. Then, the main lens is formed between the second focusing electrode 5 and the anode 6.

The first focusing electrode 4 has a constant first focus voltage V _fc , the anode 6 has a constant high voltage V _a , and the second focusing electrode 5 has _a constant first focus voltage V _fc as the electron beam is deflected. A dynamic voltage V _d that changes to a value higher than V _fc is applied.

As a result, at the time when the horizontal deflection becomes zero, that is, when the first focusing electrode 4 and the second focusing electrode 5 both have the same potential, the electron beam passage holes of both electrodes are vertically or horizontally long. , These shapes have almost no effect on the electron beam.

Then, a potential difference is generated between the second focusing electrode 5 and the anode 6, a main lens is formed there, and the three electron beams are focused with optimum focus at the center of the screen. When the horizontal deflection angle is increased, the potential of the second focusing electrode 5 becomes higher than that of the first focusing electrode 4, and a quadrupole electric field is generated between the two electrodes by the vertical electrode pair 41 and the horizontal electrode pair 51. Further, since the potential difference between the second focusing electrode 5 and the anode 6 is reduced, the lens action of the main lens is weakened.

FIG. 13 is a partial plan view for explaining the main structure of FIG. 12, and is an explanatory view of the lens action by the quadrupole electric field.

V _{1 is} applied to the vertical electrode pair 41 of the first focusing electrode 4,
A potential V _{2 is} applied to the horizontal electrode pair 51 of the second focusing electrode 4,
The quadrupole lens electric field generated between both electrodes under the condition of V ₁ <V ₂ is as shown in the figure. The equipotential lines forming the electric field of the quadrupole lens have a potential vector as shown by B _H2 .

Due to the electric field of the quadrupole lens, forces F _{V and} F _H that diverge in the vertical direction (vertical direction) and focus in the horizontal direction (horizontal direction) act on the electron beam B and have a vertically long cross-sectional shape. Will be things. This is contrary to the case where the electron beam passing through the deflection magnetic field has a horizontally long cross-sectional shape due to the quadrupole component as shown in FIG. 10C, and the horizontal length of the electron beam is canceled by canceling the vertical and horizontal lengths. It is intended to prevent flattening.

Further, as the deflection angle increases, the focusing action in the main lens becomes weak as described above, so that overfocusing due to the deflection of the beam spot can be prevented at the same time, and the diameter is small in the peripheral portion of the screen. A beam spot close to a perfect circle is generated.

In the color cathode ray tube equipped with the above electron gun, it is necessary to converge three electron beams to one point on the screen. However, the application of the dynamic voltage to the second focusing electrode changes the force for converging the side beam with the change in the lens magnification with respect to the final accelerating electrode, resulting in convergence deviation.

[0026]

As one of the methods for improving the above-mentioned convergence deviation, in a quadrupole lens composed of a first focusing electrode and a second focusing electrode, the first focusing electrode is vertically long or electron Three circular electron beam passage holes corresponding to the number of beams are provided, and a plurality of parallel plate electrodes (vertical electrode pairs) are arranged in the second focusing electrode direction so as to sandwich the electron beam passage holes from the electron beam arrangement direction. Have,
The height of the vertical electrode plate outside the side electron beam passage hole is set higher than that of the vertical electrode plate on the side of the center electron beam passage hole, and the second focusing electrode is horizontally long or has three circular shapes corresponding to the number of electron beams. There is a system in which one or three pairs of parallel plate electrodes (horizontal electrode pairs) are provided in the direction of the first focusing electrode so as to sandwich the electron beam passage holes from the direction perpendicular to the electron beam arrangement direction.

In the color cathode ray tube including the electron gun constructed as described above, the beam spot diameter of each of the three electron beams on the screen or its shape is improved by adopting a quadrupole lens. However, in order to operate as a color cathode ray tube, the focusing points of the three electron gun beams must be converged to one point at all positions on the screen.

However, between the center and the periphery of the screen, the voltage applied to the second focusing display changes, and the lens strength of the main lens also changes, so the convergence characteristics of the main lens change and a convergence shift occurs.

One means for solving the above problem is Japanese Patent Laid-Open No. 2-
No. 189842.

FIG. 14 is an explanatory view of the structure of the electron gun disclosed in the above publication, (a) is a cross-sectional view taken along the arrangement plane of electron beams, and (b) is a direction A of (a). The front view seen from the direction, (c) is the front view seen from the B direction of (a).

In the figure, the same reference numerals as those in FIG. 12 correspond to the same portions, and a plurality of vertical electrode pairs 41 extending in the direction of the second focusing electrode 5 are installed on the first focusing electrode 4 and the second focusing electrode 4 is provided. 5 is provided with a pair of vertical electrodes 51 extending in the direction of the first focusing electrode 4.

The vertical electrode pair 41 of the first focusing electrode 4 is
Is the height h of the vertical electrode outside the side beam passage hole 4s.
₁ is higher than the height h ₂ of the inner vertical electrode in the second focusing electrode 5 direction.

Therefore, an inclined electric field is formed in the quadrupole lens portion, and the deviation of convergence in the main lens is canceled by deflecting the electron beam in the opposite direction, and the deviation of convergence in the periphery of the screen is improved.

However, the vertical plate on the inside of the side beam forms a quadrupole lens for the center beam, and lowering the height of the inside vertical plate lowers the correction sensitivity of astigmatism to the center beam. Will end up.

Therefore, there is a problem that it is difficult to independently adjust the correction sensitivity and the convergence deviation.

Further, the side beam is deflected in the direction of the center beam by the quadrupole lens in order to improve the convergence deviation, and passes through the part where the electric field is slightly off the center and the electric field is strong. Astigmatism correction sensitivity becomes stronger.

For this reason, there is a problem that the astigmatism correction sensitivities of the center and the side are more likely to spread.

The object of the present invention is to solve the above-mentioned problems of the prior art and to introduce a new electrode structure in the quadrupole lens section,
An object of the present invention is to provide a color cathode ray tube equipped with an electron gun in which the astigmatism correction sensitivities of the center and side electron beams can be easily matched.

[0039]

The above object is to apply a voltage that changes with a change in the deflection angle of an electron beam to at least the second focusing electrode, and to arrange an electron beam array to the second focusing electrode. A horizontal electrode pair extending in the direction of the first focusing electrode so as to sandwich each electron beam from a direction perpendicular to the direction is installed, and the horizontal electrode pair has an asymmetrical shape on both sides of a portion corresponding to the center of the trajectory of the side beam. And the area on the side of the central beam with respect to the center of the side beam orbit is larger than the area on the opposite side of the center beam, at least near the center of the side beam orbit.

In the above structure, the tilted electric field is formed by the horizontal electrode pair, and the horizontal electrode pair has the upper and lower parts (vertical direction upper and lower parts) of the center beam and the side beam which form quadrupole lenses independently of each other. In order to correct the convergence deviation for the beam, even if the shape is changed, it does not affect the astigmatism correction sensitivity of the center beam, so the astigmatism correction sensitivity and the convergence deviation should be adjusted independently. You can

That is, the first aspect of the present invention is to provide a cathode for emitting three electron beams arranged in one direction, and a control electrode, an acceleration electrode, and a focusing electrode facing the cathode. In a color cathode ray tube having an electron gun having an electrode and an anode in a tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and the second focusing electrode deflects at least an electron beam. A pair of horizontal electrodes are applied in parallel to the first focusing electrode direction so as to sandwich the three electron beams from a direction perpendicular to the electron beam arrangement direction and a voltage that changes with a change in angle is applied. An electron beam is provided which is provided with an electrode pair and is asymmetric with respect to the orbital center of the electron beam in a region sandwiching each electron beam located on each side of the three electron beams of the pair of horizontal electrode pairs and having a center. Wherein the area of with great comprising a shape than the area opposite to the electron beam of the center.

A second aspect of the present invention is directed to a cathode for emitting three electron beams arranged in one direction, and a control electrode, an acceleration electrode, and a focusing electrode facing the cathode. In a color cathode ray tube having an electron gun having an electrode and an anode in a tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and the second focusing electrode deflects at least an electron beam. A voltage that changes with a change in angle is applied, and three extending parallel to the first focusing electrode direction so as to sandwich each of the three electron beams from a direction perpendicular to the electron beam arrangement direction. A pair of horizontal electrode pairs is installed, and the horizontal electrode pair sandwiching an electron beam located on each side of the three pairs of horizontal electrode pairs is asymmetric with respect to the orbital center of the electron beam and the electron from the center of the orbital center Bee Wherein the area of the side is provided with a shape which is larger than the area of the opposite side to the electron beam of the center.

Further, the third invention according to claim 3 is
A color cathode ray tube having a cathode for emitting three electron beams arranged in one direction, and an electron gun provided with a control electrode, an acceleration electrode, a focusing electrode and an anode in the tube axial direction facing the cathode. In the above, the focusing electrode includes at least a first focusing electrode and a second focusing electrode, and the second focusing electrode is applied with a voltage that changes at least in accordance with a change in the deflection angle of the electron beam, and the electron beam array is arranged. A pair of horizontal electrode pairs extending toward the first focusing electrode direction so as to sandwich the three electron beams from a direction perpendicular to the direction is installed, and electrons located on each side of the pair of horizontal electrode pairs are arranged. It is characterized in that it has a shape in which the electrode interval in the region sandwiching the beam gradually increases in the direction away from the tube axis.

Further, a fourth invention according to claim 4 is
A color cathode ray tube having a cathode for emitting three electron beams arranged in one direction, and an electron gun provided with a control electrode, an acceleration electrode, a focusing electrode and an anode in the tube axial direction facing the cathode. In the above, the focusing electrode includes at least a first focusing electrode and a second focusing electrode, and the second focusing electrode is applied with a voltage that changes at least in accordance with a change in the deflection angle of the electron beam, and the electron beam array is arranged. Three pairs of horizontal electrode pairs extending toward the first focusing electrode direction so as to sandwich each of the three electron beams from a direction perpendicular to the direction are installed, and among the three pairs of horizontal electrodes, It is characterized in that the electrode interval of the horizontal electrode pair sandwiching the electron beam located on each side is gradually increased in the direction away from the tube axis.

Further, the fifth invention according to claim 5 is
A color cathode ray tube having a cathode for emitting three electron beams arranged in one direction, and an electron gun provided with a control electrode, an acceleration electrode, a focusing electrode and an anode in the tube axial direction facing the cathode. In the above, the focusing electrode includes at least a first focusing electrode and a second focusing electrode, and the second focusing electrode is applied with a voltage that changes at least in accordance with a change in the deflection angle of the electron beam, and the electron beam array is arranged. A pair of horizontal electrode pairs extending toward the first focusing electrode direction so as to sandwich the three electron beams from a direction perpendicular to the direction is installed, and the electrode interval of the pair of horizontal electrode pairs is located at the center. It is characterized in that it has a shape that gradually increases in the direction away from the tube axis with respect to the electron beams located at the minimum on both sides in the area facing the electron beam.

Further, the sixth invention according to claim 6 is
A color cathode ray tube having a cathode for emitting three electron beams arranged in one direction, and an electron gun provided with a control electrode, an acceleration electrode, a focusing electrode and an anode in the tube axial direction facing the cathode. In the above, the focusing electrode includes at least a first focusing electrode and a second focusing electrode, and the second focusing electrode is applied with a voltage that changes at least in accordance with a change in the deflection angle of the electron beam, and the electron beam array is arranged. A pair of horizontal electrode pairs extending parallel to the first focusing electrode direction so as to sandwich the three electron beams from a direction perpendicular to the direction, and an electron beam arrangement direction of the pair of horizontal electrode pairs. The length is shorter than the length of the line connecting the orbital centers of the electron beams located on each side.

The seventh invention according to claim 7 is:
An electron beam in which three electron beams pass through each of the facing surfaces of the first focusing electrode and the second focusing electrode according to any one of the first, second, third, fourth, fifth, and sixth inventions. A vertical hole having a through hole and extending in the second focusing electrode direction and between the electrodes of the horizontal electrode pair so as to sandwich each of the three electron beams in the first focusing electrode from the arrangement direction of the electron beams. It is characterized in that an electrode pair is installed.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a color cathode ray tube according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view taken along a center electron beam parallel to the vertical direction for explaining an example of an in-line type electron gun used for a color cathode ray tube of the present invention. Control electrode, 3 is accelerating electrode, 4 is first
Focusing electrode, 4 second focusing electrode, 5 final accelerating electrode (anode), 41 vertical electrode pair, 51 horizontal electrode pair, and 4s
Is a side electron beam (side beam) of the first focusing electrode 4.
Passage holes 4c are center electron beam (center beam) passage holes of the first focusing electrode 4, 5s are side electron beam (side beam) passage holes of the second focusing electrode 5, and 5c is a center electron beam of the second focusing electrode 5. It is a (center beam) passage hole.

In the figure, the first focusing electrode 4 has three circular electron beam passage holes on the surface facing the second focusing electrode 5, and each of these electron beam passage holes 4 is sandwiched from the horizontal direction. It has a single vertical electrode 41. The second focusing electrode 5 has three circular electron beam passage holes on the surface facing the first focusing electrode 4, and two vertical electrodes 51 sandwiching these electron beam passage holes from the vertical direction.
have. Then, the main lens is formed between the second focusing electrode 5 and the anode 6.

A dynamic voltage that changes with the deflection of the electron beam is applied to either the first focusing electrode 4 or the second focusing electrode 5.

FIG. 2 is an explanatory view of the main structure of FIG.
1A is a front view of the first focusing electrode 4 viewed from the AA ′ direction in FIG. 1, FIG. 1B is a front view of the second focusing electrode 4 viewed from the BB ′ direction in FIG. 1, and FIG. It is sectional drawing of the quadrupole lens part cut | disconnected along CC 'line of FIG.

As shown in FIG. 7A, the quadrupole lens is an electron beam passage hole 5s, 5c, 5s of the second focusing electrode 5.
Horizontal electrode pairs 51, 5 installed so as to sandwich the electron beam passing through it from the direction perpendicular to the arrangement direction of the electron beams.
1'and electron beam passage holes 4s, 4 of the first focusing electrode 4
Each of the electron beams passing through c and 4s is composed of a pair of vertical electrodes 41 arranged so as to sandwich each of the electron beams from the arrangement direction of the electron beams.

As shown in FIG. 7C, the horizontal electrode pair 5
Since the corners of 1, 51 ′ are cut off from the horizontal plane of the electron beam passage hole of the second focusing electrode 5 toward the first focusing electrode 4 and toward the center electron beam, the outside of the first focusing electrode pair 41. Vertical electrode pair (one outside)
A gradient electric field for correcting the deviation of the side beam convergence is formed inside.

This tilted electric field exerts a focusing action on the electron beam, and acts so as to bend the side beam in the direction of the center beam.

As a result, the astigmatism correction sensitivity and the convergence shift can be adjusted independently, and the color equipped with an electron gun that easily matches the astigmatism correction sensitivities of the center and side electron beams. A cathode ray tube can be provided.

FIG. 3 is a schematic plan view of a horizontal electrode pair installed on the second focusing electrode for explaining another example of the in-line type electron gun used for the color cathode ray tube of the present invention.

In this example, the horizontal electrode pairs shown in FIGS. 1 and 2 are divided into three electron beam pairs to form three pairs.

In the electron gun adopting this horizontal electrode pair, a gradient electric field for correcting the deviation of the side beam convergence is formed outside the first focusing electrode 4 inside the vertical electrode pair, and the same as in the above example. The effect of is obtained.

FIG. 4 shows a structure of a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode for explaining still another example of the in-line type electron gun used for the color cathode ray tube of the present invention. FIG. 3 is a schematic view of the device viewed from the axial direction of the electron gun.

In this example, three electron beam passage holes s,
The horizontal electrode pairs 51 and 51 'sandwiching c and s from the vertical direction are arranged such that the electrode spacing therebetween is larger than the center beam along the side beam direction.

With this structure, a gradient electric field for correcting the convergence deviation of the side beam is formed inside the pair of vertical electrodes (one side) which is partitioned outside the first focusing electrode 4. Similar to the above, this gradient electric field exerts a focusing effect on the electron beam to act to bend the side beam toward the center beam.

FIG. 5 is a constitution of a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode for explaining still another example of the in-line type electron gun used for the color cathode ray tube of the present invention. FIG. 3 is a schematic view of the device viewed from the axial direction of the electron gun.

In this example, three electron beam passage holes s,
Horizontal electrode pairs 51 and 51 'sandwiching c and s from the vertical direction are composed of three pairs of electrodes divided for each electron beam, and the electrode interval corresponding to the side beam is large toward the outside in the side beam direction. It is installed so that.

With this structure, a gradient electric field for correcting the convergence deviation of the side beam is formed inside the pair of vertical electrodes (one of) which is partitioned outside the first focusing electrode 4. Similar to the above, this gradient electric field exerts a focusing effect on the electron beam to act to bend the side beam toward the center beam.

FIG. 6 is a constitution of a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode for explaining still another example of the in-line type electron gun used for the color cathode ray tube of the present invention. FIG. 3 is a schematic view of the device viewed from the axial direction of the electron gun.

In this example, three electron beam passage holes s,
c, the horizontal direction length D ₂ of the horizontal electrode pairs 51 and 51 'sandwiching s from the vertical direction is shorter than the electron beam passage holes s, distance D ₁ of the inter-s of side electron beams.

With this structure, an inclined electric field for correcting the convergence deviation of the side beam is formed inside (one of) the vertical electrode pairs partitioning outside the first focusing electrode 4. Similar to the above, this gradient electric field exerts a focusing effect on the electron beam to act to bend the side beam toward the center beam.

FIG. 7 is a constitution of a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode for explaining still another example of the in-line type electron gun used for the color cathode ray tube of the present invention. FIG. 3 is a schematic view of the device viewed from the axial direction of the electron gun.

In this example, three electron beam passage holes s,
The electrode thickness of the horizontal electrode pair 51, 51 'is outside so that the electrode spacing of the horizontal electrode pair 51, 51' sandwiching c and s from the vertical direction becomes gradually larger along the side beam direction than the center beam. It is installed as a shape that gradually becomes thinner toward.

With this configuration, a gradient electric field for correcting the side beam convergence deviation is formed inside the vertical electrode pair (one side) partitioning outside the first focusing electrode 4. Similar to the above, this gradient electric field exerts a focusing effect on the electron beam to act to bend the side beam toward the center beam.

FIG. 8 is a constitution of a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode for explaining still another example of the in-line type electron gun used for the color cathode ray tube of the present invention. FIG. 3 is a schematic view of the device viewed from the axial direction of the electron gun.

In this example, three electron beam passage holes s,
The electrodes of the horizontal electrode pair 51, 51 'are curved so that the electrode interval of the horizontal electrode pair 51, 51' sandwiching c and s from the vertical direction becomes gradually larger along the side beam direction than the center beam. is set up.

With this structure, a gradient electric field for correcting the convergence deviation of the side beam is formed inside the pair of vertical electrodes (one side) which is partitioned outside the first focusing electrode 4. Similar to the above, this gradient electric field exerts a focusing effect on the electron beam to act to bend the side beam toward the center beam.

As described above, by providing the color cathode ray tube with the electron gun having the quadrupole lens structure shown in each of the above examples, it is possible to reproduce a high resolution image in the entire area of the screen.

As described above, the present invention is not limited to the electron gun having a single-stage focusing electrode, but can be applied to an electron gun having multi-stage focusing electrodes. Further, in the above embodiment, an in-line type electron gun having three cathodes was described as an example, but the invention is not limited to this, and an electron gun having a single beam or various kinds of electrons having a plurality of beams other than three beams is used. It can also be applied to various cathode ray tubes equipped with guns and their electron guns.

FIG. 9 is a sectional view for explaining the construction of an example of an in-line type color cathode ray tube according to the present invention, in which 80 is a panel portion, 81 is a neck portion, 82 is a funnel portion, and 83.
Is a fluorescent screen, 84 is a shadow mask, 85 is a mask frame, 86 is a magnetic shield, 87 is a mask suspension mechanism, 88
Is an electron gun, 89 is a deflection yoke, 90 is a correction magnetic device, B
c and Bs are electron beams.

This color cathode ray tube has a neck portion 81 for accommodating a panel portion 80 constituting a screen and an electron gun 88.
Also, a vacuum envelope is constituted by the funnel portion 82 connecting the panel portion 80 and the neck portion 81, and the fluorescent surface 83 formed of a phosphor mosaic of three colors applied to the inner surface of the panel portion 80.
A predetermined image is formed by selecting the three electron beams emitted from the electron gun 88 by a shadow mask 84 suspended in close proximity to and then projecting them onto a predetermined phosphor.

The electron gun 88 is equipped with the quadrupole lens having the above-mentioned structure, and a high resolution image can be obtained over the entire area of the screen.

[0080]

As described above, according to the present invention,
It is possible to provide a high-quality color cathode ray tube in which the spot diameter of the electron beam is small and a high resolution can be obtained while maintaining a close to a perfect circle, and the deviation of the convergence is corrected over the entire area of the screen.

Also, since the axis alignment and assembly of the electron gun are easy, a highly reliable electron gun having good reproducibility can be obtained, and a high quality color cathode ray tube can be obtained by using the electron gun.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along a center electron beam parallel to a vertical direction for explaining an example of an in-line type electron gun used for a color cathode ray tube of the present invention.

FIG. 2 is an explanatory diagram of a main part configuration of FIG.

FIG. 3 is a schematic plan view of a horizontal electrode pair installed on a second focusing electrode for explaining another example of the in-line type electron gun used for the color cathode ray tube of the present invention.

FIG. 4 is a schematic view showing still another example of the in-line type electron gun used for the color cathode ray tube of the present invention, in which the vertical electrode pair installed on the first focusing electrode and the horizontal electrode pair installed on the second focusing electrode are electron-configured. It is a schematic diagram seen from the axial direction of the gun.

FIG. 5 is a view showing another example of the in-line type electron gun used for the color cathode-ray tube of the present invention, in which a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode are configured as an electron. It is a schematic diagram seen from the axial direction of the gun.

FIG. 6 is a schematic view showing still another example of the in-line type electron gun used in the color cathode ray tube of the present invention, in which the vertical electrode pair installed on the first focusing electrode and the horizontal electrode pair installed on the second focusing electrode are electron-configured. It is a schematic diagram seen from the axial direction of the gun.

FIG. 7 is a view showing still another example of the in-line type electron gun used for the color cathode ray tube according to the present invention, in which a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode are configured as an electron. It is a schematic diagram seen from the axial direction of the gun.

FIG. 8 is a view showing still another example of an in-line type electron gun used for the color cathode ray tube of the present invention, in which a vertical electrode pair installed on the first focusing electrode and a horizontal electrode pair installed on the second focusing electrode are electron-configured. It is a schematic diagram seen from the axial direction of the gun.

FIG. 9 is a cross-sectional view illustrating the configuration of an example of an in-line type color cathode ray tube according to the present invention.

FIG. 10 is a schematic diagram showing the relationship between the horizontal deflection magnetic field of the pincushion magnetic field distribution and the deflection of the electron beam.

FIG. 11 is an explanatory diagram of a screen-shaped electron beam spot shape.

FIG. 12 is a perspective view illustrating a structure of an electron gun in a conventional color cathode ray tube.

13 is a partial plan view illustrating the structure of the main part in FIG.

FIG. 14 is an explanatory diagram of a structure example of a conventional electron gun.

[Explanation of symbols]

1 Cathode 2 Control Electrode 3 Accelerating Electrode 4 First Focusing Electrode 4 Second Focusing Electrode 5 Final Accelerating Electrode (Anode) 41 Vertical Electrode Pair 51 Horizontal Electrode Pair 4s Side Electron Beam (Side Beam) Passage Hole 4c of First Focusing Electrode 4c Center electron beam (center beam) passage hole of the first focusing electrode 5s Side electron beam (side beam) passage hole of the second focusing electrode 5c Center electron beam (center beam) passage hole of the second focusing electrode 5

Claims (7)

[Claims] 1. A cathode for emitting three electron beams arranged in one direction, and a control electrode facing the cathode.
In a color cathode ray tube having an electron gun provided with an accelerating electrode, a focusing electrode, and an anode in the tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and at least the second focusing electrode has at least the second focusing electrode. A voltage that changes with a change in the deflection angle of the electron beam is applied, and the voltage is extended in parallel toward the first focusing electrode direction so as to sandwich the three electron beams from a direction perpendicular to the electron beam arrangement direction. A pair of horizontal electrode pairs to be installed, asymmetric with respect to the orbital center of the electron beam in the region sandwiching each electron beam located on each side of the three electron beams of the pair of horizontal electrode pairs and A color cathode ray tube, characterized in that the area of the center on the electron beam side is larger than the area of the center on the side opposite to the electron beam. 2. A cathode for emitting three electron beams arranged in one direction, a control electrode facing the cathode,
In a color cathode ray tube having an electron gun provided with an accelerating electrode, a focusing electrode, and an anode in the tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and at least the second focusing electrode has at least the second focusing electrode. A voltage that changes with a change in the deflection angle of the electron beam is applied, and the three electron beams are sandwiched in parallel from the direction perpendicular to the electron beam arrangement direction toward the first focusing electrode direction. Three extending horizontal electrode pairs are installed, and horizontal electrode pairs sandwiching an electron beam located on each side of the three horizontal electrode pairs are asymmetric with respect to the orbital center of the electron beam and the orbital center. A color cathode ray tube having a shape in which an area on the electron beam side of the center is larger than an area on the side opposite to the electron beam of the center. 3. A cathode for emitting three electron beams arranged in one direction, a control electrode facing the cathode,
In a color cathode ray tube having an electron gun provided with an accelerating electrode, a focusing electrode, and an anode in the tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and at least the second focusing electrode has at least the second focusing electrode. A pair of voltages is applied along with a change in the deflection angle of the electron beam, and extends in the direction of the first focusing electrode so as to sandwich the three electron beams from a direction perpendicular to the electron beam arrangement direction. The horizontal cathode electrode pair is installed, and the electrode interval of the region sandwiching the electron beam located on each side of the pair of horizontal electrodes is gradually increased in the direction away from the tube axis. 4. A cathode for emitting three electron beams arranged in one direction, a control electrode facing the cathode,
In a color cathode ray tube having an electron gun provided with an accelerating electrode, a focusing electrode, and an anode in the tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and at least the second focusing electrode has at least the second focusing electrode. A voltage that changes in accordance with a change in the deflection angle of the electron beam is applied and extends in the direction of the first focusing electrode so as to sandwich each of the three electron beams from a direction perpendicular to the electron beam arrangement direction. 3 pairs of horizontal electrode pairs are installed, and the electrode spacing of the horizontal electrode pairs sandwiching the electron beam located on each side of the 3 pairs of horizontal electrode pairs is gradually increased in a direction away from the tube axis. Is a color cathode ray tube. 5. A cathode for emitting three electron beams arranged in one direction, a control electrode facing the cathode,
In a color cathode ray tube having an electron gun provided with an accelerating electrode, a focusing electrode, and an anode in the tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and at least the second focusing electrode has at least the second focusing electrode. A pair of voltages is applied along with a change in the deflection angle of the electron beam, and extends in the direction of the first focusing electrode so as to sandwich the three electron beams from a direction perpendicular to the electron beam arrangement direction. Horizontal electrode pairs are installed, and the electrode spacing of the pair of horizontal electrode pairs is the smallest in the region facing the electron beam located in the center and gradually increases in the direction away from the tube axis with respect to the electron beams located on both sides. A color cathode ray tube characterized by having. 6. A cathode for emitting three electron beams arranged in one direction, a control electrode facing the cathode,
In a color cathode ray tube having an electron gun provided with an accelerating electrode, a focusing electrode, and an anode in the tube axis direction, the focusing electrode comprises at least a first focusing electrode and a second focusing electrode, and at least the second focusing electrode has at least the second focusing electrode. A voltage that changes with a change in the deflection angle of the electron beam is applied, and the voltage is extended in parallel toward the first focusing electrode direction so as to sandwich the three electron beams from a direction perpendicular to the electron beam arrangement direction. A pair of horizontal electrode pairs is provided, and the length of the pair of horizontal electrode pairs in the electron beam array direction is shorter than the length of a line connecting the orbit centers of the electron beams located on each side. 7. An electron beam according to claim 1, 2, 3, 4, 5, or 6, wherein three electron beams pass through respective facing surfaces of the first focusing electrode and the second focusing electrode. A vertical hole having a through hole and extending in the second focusing electrode direction and between the electrodes of the horizontal electrode pair so as to sandwich each of the three electron beams in the first focusing electrode from the arrangement direction of the electron beams. A color cathode ray tube having a pair of electrodes installed.