JPH08129967A - Color picture tube device - Google Patents

Abstract

PURPOSE: To reduce collapse of a beam spot or the like by connecting electrodes to each other so that intensities of a focusing intensity-adjusted prefocus lens, a sub-lens and a main lens are simultaneously changed by a dynamic change of a quardrupole lens. CONSTITUTION: In a prefocus lens formed of second and third grids G2 and G3 , an electron beam is strongly focused in the perpendicular direction more than the horizontal direction. In a sub-lens formed of third and fourth grids G3 and G4 and a fifth grid G51 , it is strongly focused in the horizontal direction more than the perpendicular direction. When the electron beam is deflected, voltage of the grids G3 and G51 is raised, and a reducing effect of an object point diameter in the horizontal direction to a main lens formed of the fifth grid G53 and a sixth grid G6 is obtained. Since voltage of the grids G51 and G53 is raised, deflection aberration by a magnetic field of a deflection device is corrected by a quardrupole lens formed of the fifth grids G51 , G52 and G53 . Therefore, collapse on the whole surface of an image screen of a beam spot and a horizontal directional blur in a peripheral part are reduced.

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 apparatus, and more particularly to a color picture tube apparatus in which deterioration of image quality due to collapse of a beam spot is reduced.

[0002]

2. Description of the Related Art Generally, in a color picture tube device, a phosphor screen made of a phosphor layer of three colors is formed on the inner surface of a panel of an envelope made of a panel and a funnel. A shadow mask is placed on. On the other hand, an electron gun that emits three electron beams is arranged in the neck of the funnel. Then, the electron beam emitted from the electron gun is deflected by the horizontal and vertical deflection magnetic fields generated by the deflection device mounted outside the funnel, and the phosphor screen is horizontally and vertically scanned to display a color image. Is formed into a structure.

In such a color picture tube device, in particular, the electron gun is an in-line type electron gun which emits three electron beams arranged in a line consisting of a center beam passing through the same horizontal plane and a pair of side beams. hand,
Pincushion type horizontal deflection magnetic field generated by the deflection device,
A self-convergence in-line type color picture tube, which has a vertical deflection magnetic field of a barrel shape and self-focuses the three electron beams arranged in a row, is currently the mainstream of the color picture tube.

There are various structures of electron guns that emit three electron beams arranged in a row, and one of them is Q.
There is a PF (Quadra Potential Focus) type double focus electron gun. As shown in FIG. 5, this electron gun has three cathodes K arranged in a line in the horizontal (X-axis) direction, and first to fourth grids G1 to G1 arranged sequentially from the cathode K in the phosphor screen direction. G4, three divided fifth grids G51, G52, G53 and sixth grid G
It consists of six. In each grid, three electron beam passage holes are formed corresponding to the three cathodes K arranged in a row.

In this electron gun, the cathode K has about 150 V
Voltage is applied, the first grid G1 is grounded, and the second grid G1 is grounded.
Electron beam deflection to a voltage of about 800 V to the grid G2, about 6 kV to the third grid G3, about 800 V when the fourth grid G4 is connected to the second grid G2, and about 6 kV to the fifth grid G51. A dynamic voltage with a parabola-shaped voltage increasing in accordance with
The grid G52 is connected to the third grid G3 and is about 6 k
V and the fifth grid G53 are connected to the fifth grid G51 and the dynamic voltage is applied thereto, and a high voltage (anode voltage) of about 26 kV is applied to the sixth grid G6.

By applying the above voltage, the cathode K
And the first and second grids G1 and G2 form a triode that generates an electron beam and forms an object point for the main lens, which will be described later, and the second and third grids G2 and G3 form the triode. A prefocus lens for prefocusing the electron beam from the third and fourth grids G3 is formed.
, G4 and the fifth grid G51 form a sub-lens for further pre-focusing the electron beam pre-focused by the pre-focus lens.
And the sixth grid G6 forms the main lens which finally focuses the electron beam onto the phosphor screen.
Three fifth grids G51, G52, G divided into three
53 forms a quadrupole lens that changes according to the deflection of the electron beam.

In this quadrupole lens, when the electron beam is directed to the center of the phosphor screen without being deflected by the deflecting device, the voltage applied to the fifth grids G51 and G53 becomes the lowest, and the fifth grid G52. Same potential as (about 6
kV) and the lens is not formed, but as the electron beam is deflected by the deflecting device, the fifth grid G
The voltage applied to 51 and G53 increases, forming a lens and simultaneously increasing the strength of the sub-lens including the fifth grid G51 and weakening the strength of the main lens including the fifth grid G53. As a result, the lens magnification is changed in response to the distance from the electron gun to the phosphor screen becoming larger and the image point becoming farther away, and the pincushion-type horizontal deflection magnetic field and barrel-type vertical deflection magnetic field generated by the deflection device are changed. The deflection aberration caused by the non-uniform magnetic field is corrected.

That is, in order to improve the image quality of the color picture tube device, it is necessary to improve the focusing characteristics on the phosphor screen. Generally, the in-line type that emits three electron beams arranged in a row is used. In the color picture tube device, as shown in FIG. 6, a blur 2 occurs in the vertical (Y-axis) direction of the beam spot 1 at the peripheral portion of the screen due to the deflection aberration. However, when the fifth grid forming the low voltage electrode of the main lens is divided and the quadrupole lens is formed according to the deflection of the electron beam as in the double focus type electron gun, as shown in FIG. The vertical bleeding of the beam spot 1 at the peripheral portion of the screen caused by the deflection aberration can be eliminated.

However, in this double focus type electron gun, as shown in FIG. 7 for the beam spot 1 at the horizontal axis (X-axis) end and the diagonal axis end of the screen, the beam spot in the peripheral portion of the screen is crushed and becomes horizontally long. However, there is a problem that the horizontally elongated beam spot 1 interferes with the electron beam passage hole of the shadow mask to cause moire on the screen, making it difficult to see characters displayed on the screen. .

As an electron gun for solving such a problem,
Electrons that reach the center of the phosphor screen are formed by forming horizontally long grooves around the electron beam passage holes on the surface of the second grid facing the third grid to reduce the object point diameter in the horizontal direction with respect to the main lens. As shown in FIG. 8, the cross-sectional shape of the beam is set to be vertically long, and the horizontally long shape of the beam spot 1 at the peripheral portion of the screen is relaxed to eliminate moire due to interference with the electron beam passage hole of the shadow mask at the peripheral portion of the screen. There is something like this. In this case, the beam spot 1 at the center of the screen is vertically long.

According to this electron gun, the deeper the horizontally long groove of the second grid is, the smaller the diameter of the object point in the horizontal direction with respect to the main lens can be reduced, and the horizontally elongated shape of the beam spot 1 can be relaxed to a greater extent. However, with this electron gun, since the horizontal divergence angle of the electron beam expands simultaneously with the reduction of the horizontal object point diameter, spherical aberration in the main lens increases, and as shown in FIG. There is a problem that bleeding 2 occurs in the horizontal direction of the beam spot 1 of the part, and it becomes difficult to see characters and the like displayed on the screen.

[0012]

As described above, in order to improve the image quality of the self-converging in-line type color picture tube, the influence of the deflection aberration is minimized and the beam spot at the periphery of the screen is minimized. It is desirable to alleviate the laterally elongated shape and to reduce the bleeding of the beam spot.

In this respect, in the conventional QPF type double focus type electron gun, by applying a dynamic voltage increasing with the deflection of the electron beam to the electrodes forming the quadrupole lens, the vertical direction of the beam spot caused by the deflection aberration. Bleeding can be eliminated. However, with this QPF type double focus electron gun, the horizontally long shape of the beam spot in the peripheral portion of the screen cannot be relaxed, and this horizontally long beam spot interferes with the electron beam passage hole of the shadow mask to cause moire on the screen. Occurs, which causes a problem that it is difficult to see characters and the like displayed on the screen.

As an electron gun for alleviating the oblong shape of the beam spot in the peripheral portion of the screen, there is an electron gun in which a oblong groove is formed around the electron beam passage hole on the surface facing the third grid of the second grid. , With this electron gun, the horizontal shape of the beam spot around the screen can be relaxed,
Bleeding occurs in the horizontal direction of the beam spot in the peripheral portion of the screen, which makes it difficult to see characters displayed on the screen as with the electron gun.

The present invention has been made in order to solve the above problems, and is a color picture tube device in which the beam spot is less crushed over the entire screen, and the horizontal bleeding of the beam spot in the peripheral portion of the screen is small. The purpose is to configure.

[0016]

An electron gun composed of a cathode and a plurality of electrodes arranged in the phosphor screen direction from the cathode, and horizontal and vertical deflection magnetic fields for deflecting an electron beam emitted from the electron gun are generated. Tripolar part that is equipped with a deflector and generates an electron beam by the cathode and multiple electrodes, a prefocus lens that prefocuses the electron beam from this tripole part, and a prefocused electron beam that is prefocused by this prefocus lens. Focusing sub-lens, main lens that finally focuses the electron beam prefocused by these pre-focusing lens and sub-lens on the phosphor screen, and between the sub-lens and the main lens by applying dynamically changing voltage Dynamically changing quadrupole lens for correcting deflection aberration caused by a magnetic field generated by a deflecting device In the color picture tube apparatus for forming, to form a stronger lens than the focusing of the focusing in the horizontal direction of the pre-focus lens is vertically, sub-lens has the focusing in the horizontal direction to form a stronger lens than focusing in the vertical direction,
Pre-focus lens by dynamic change of quadrupole lens,
The electrodes forming these sub-lenses and the main lens were connected to the dynamically applied voltage-applied electrodes of the quadrupole lens so that the strengths of the sub-lens and the main lens changed simultaneously.

Further, an electron gun comprising a cathode and first, second, third and fourth electrodes arranged in the phosphor screen direction from the cathode, three divided fifth electrodes and a sixth electrode, and A deflection device for generating horizontal and vertical deflection magnetic fields for deflecting an electron beam emitted from this electron gun is provided, and a cathode and first and second electrodes are used to generate an electron beam. The prefocus lens for prefocusing the electron beam from the triode, the third and fourth electrodes, and one of the fifth electrodes adjacent to the fourth electrode further prefocus the electron beam prefocused by the prefocus lens. The sub-lens, the sixth electrode, and one of the fifth electrodes adjacent to the sixth electrode to finally generate the electron beam prefocused by the prefocus lens and the sub-lens. A dynamically changing voltage is applied to one of the main lens that focuses on the phosphor screen and the fifth electrode that is adjacent to the fourth electrode. By applying this voltage, the three lenses of the fifth electrode cause the main lens and the main lens to move. In a color picture tube device that forms a dynamically changing quadrupole lens that corrects the deflection aberration generated by the magnetic field generated by the deflecting device between the lens and the lens, the prefocus lens has vertical focusing rather than horizontal focusing. A strong lens is formed, the sub-lens forms a lens in which the horizontal focusing is stronger than the vertical focusing, and the dynamics of the quadrupole lens cause the strengths of the prefocus lens, sub-lens, and main lens to change simultaneously. One of the fifth electrode adjacent to the third electrode and the sixth electrode forming each of these lenses and one of the fifth electrodes adjacent to the fourth electrode to which a dynamically changing voltage is applied. It was connected to.

[0018]

With the above arrangement, when the electron beam emitted from the electron gun goes to the center of the phosphor screen without being deflected by the deflecting device, the electron beam from the triode part is emitted from the prefocus lens. Due to the stronger focusing effect in the vertical direction than in the horizontal direction, the negative astigmatism is stronger in the vertical direction than in the horizontal direction. In this case, the object point diameter in the horizontal direction with respect to the main lens is reduced, and the divergence angle in the horizontal direction changes as if it were enlarged. The electron beam focused by the prefocus lens is subjected to a stronger positive astigmatism in the horizontal direction than in the vertical direction due to a stronger focusing action in the horizontal direction than in the vertical direction of the sub lens. Thereby, the divergence angle of the electron beam in the horizontal direction is suppressed, and the divergence angle in the vertical direction is expanded. In this case, the quadrupole lens does not work, and the beam spot of the electron beam finally focused on the phosphor screen by the main lens has a slightly elongated shape.

On the other hand, when the electron beam is deflected to the peripheral portion of the screen by the deflecting device, the quadrupole lens dynamically changes due to the application of the dynamically changing voltage, and this quadrupole lens acts. Thus, the deflection aberration caused by the magnetic field generated by the deflecting device is corrected. At the same time, the vertical focusing is stronger than the horizontal focusing.The action of the prefocus lens is strengthened, and the horizontal object point diameter with respect to the main lens is further reduced compared to when it is not deflected, and the horizontal divergence angle is expanded. It becomes the direction to do. In addition, the action of the sub-lens, which is stronger in focusing in the horizontal direction than in focusing in the vertical direction, becomes stronger, and positive astigmatism that is stronger in the horizontal direction than in the vertical direction becomes larger. Thereby, the divergence angle of the electron beam in the horizontal direction is suppressed, and the divergence angle in the vertical direction is increased, and the divergence angle expanded by the prefocus lens is reduced. After that, the electron beam is focused by the main lens, and the beam spot on the phosphor screen has a horizontal eccentric shape with less horizontal bleeding.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 3 shows a color picture tube device as one embodiment of the invention. This color picture tube device has an envelope composed of a panel 10 and a funnel-shaped funnel 11 integrally joined to the panel 10, and an inner surface of the panel 10 has
A phosphor screen 12 is provided which is composed of a vertically elongated striped three-color phosphor layer that emits blue, green, and red light, and a shadow mask 13 is arranged inside the phosphor screen 12 so as to face the phosphor screen 12. There is. On the other hand, in the neck 14 of the funnel 11, a single row of three beams, each of which is composed of a center beam and a pair of side beams that pass on the same horizontal plane, is arranged.
An electron gun 16, which will be described later, that emits an electron beam 15 is provided. The electron gun 1 is provided outside the funnel 11.
A deflection device 17 for generating horizontal and vertical deflection magnetic fields for deflecting the 3 electron beam 15 emitted from the 6 is mounted.
Then, the three electron beams 1 emitted from the electron gun 16 are
5 is deflected by the magnetic field generated by the deflecting device 17, and the phosphor screen 12 is horizontally and vertically scanned to form a color image display structure.

The electron gun 16 is a QPF type double focus type electron gun, and as shown in FIG.
Three cathodes K arranged in a line in the axial direction, three heaters (not shown) for heating the cathodes K respectively, and first to fourth heaters sequentially arranged in the phosphor screen direction from the cathode K. The grids G1 to G4 are composed of three divided fifth grids G51, G52, G53 and a sixth grid G6. These cathodes K, heaters and first to sixth grids G1 to G4, G51, G52, G5.
3, G6 are integrally fixed by a pair of insulating supports (not shown).

The first to fourth grids G1 to G4 and the fifth grid G52 are plate electrodes and the fifth grids G51, G.
53 and the sixth grid G6 consist of tubular electrodes. Of these electrodes, the fourth grid G4 and the fifth grid G52
Corresponding to the three cathodes K, three circular electron beam passage holes each having a predetermined size are formed in a row in the horizontal direction in the electrodes other than the above. Particularly, on the surface of the second grid G2 on the third grid G3 side, as shown in FIG. 2 (a), three circular electron beam passage holes 19a, 19b, 19c are formed.
The three laterally long grooves 20 having a major axis in the horizontal direction are formed so as to surround each of them. As for the fourth grid G4 and the fifth grid G52, as shown for the fourth grid G4 in FIG. 2 (b), three vertical electrons corresponding to the three cathodes and having a major axis in the vertical direction are used. Beam passing holes 21a, 21b and 21c are formed.

In this electron gun, a voltage in which a video signal corresponding to an image is superimposed is applied to the cathode K at a voltage of 150 V, the first grid G1 is grounded, and the second grid G is grounded.
A voltage of about 800 V is applied to 2 and a dynamic voltage in which a parabolic voltage, which increases with the deflection of the electron beam, is applied to the voltage of about 6 kV to the third grid G3.
The grid G4 is connected to the second grid G2 and is approximately 800
V, the fifth grid G51 is connected to the third grid G3,
A dynamic voltage is applied to the third grid G3, the fifth grid G52 is connected to about 6 kV, the fifth grid G53 is connected to the third and fifth grids G3 and G51, and the third and fifth grids are connected. The dynamic voltage applied to G3 and G51 is applied to the sixth grid G6 at about 26.
A high voltage (anode voltage) of kV is applied.

By applying these voltages, the cathode K and the first and second grids G1 and G2 form a three-pole portion that generates an electron beam and forms an object point of the main lens, which will be described later. A prefocus lens for prefocusing the electron beam from the triode is formed by the third grids G2 and G3, and the third and fourth grids G3 and G3
The G4 and the fifth grid G51 form a sub-lens for further pre-focusing the electron beam pre-focused by the pre-focus lens, and the fifth grid G53 and the sixth grid G6 finally project the electron beam to the phosphor screen. A main lens is formed that focuses on top. A quadrupole lens that changes according to the deflection of the electron beam is formed between the sub-lens and the main lens by the three fifth grids G51, G52, and G53 divided into three.

In the quadrupole lens, when the electron beam is directed to the center of the phosphor screen without being deflected by the deflecting device, the voltage applied to the fifth grids G51 and G53 becomes the lowest and the fifth grid G52. Same potential as (about 6
kV) and no lens is formed. Therefore, when the electron beam is not deflected by the deflecting device, the electron beam from the triode is first prefocused by the prefocus lens formed by the second and third grids G2 and G3. In this case, the third grid G3 of the second grid G2
The laterally elongated groove 20 formed on the side surface causes the electron beam to
It is more strongly focused in the vertical direction than in the horizontal direction, and receives negative astigmatism that is stronger in the vertical direction than in the horizontal direction. Therefore, the electron beam reduces the object diameter in the horizontal direction with respect to the main lens by the prefocus lens, and expands the divergence angle in the horizontal direction. The electron beam focused by this prefocus lens is then fed to the third and fourth grids G3 and G3.
It is pre-focused by the sub-lens formed by the fourth and fifth grids G51. In this case, since the electron beam passage holes 21a, 21b, 21c of the fourth grid G4 are formed vertically long, the electron beam is focused more strongly in the horizontal direction than in the vertical direction and stronger in the horizontal direction than in the vertical direction. Subject to astigmatism. Thereby, the divergence angle of the electron beam in the horizontal direction is suppressed, and the divergence angle in the vertical direction is expanded. Therefore, the divergence angle in the horizontal direction enlarged by the prefocus lens is reduced by the sublens, and the stronger focusing in the vertical direction than in the horizontal direction of the prefocus lens is offset. The electron beam then passes without the lens action of the quadrupole lens and is finally focused by the main lens in the center of the phosphor screen. In this case, as shown in FIG. 4, the beam spot 23 at the center of the screen has a vertically long shape as in the case of the conventional electron gun shown in FIG.

On the other hand, when the electron beam is deflected to the peripheral portion of the screen by the deflecting device, the voltage of the third grid G3 rises in accordance with the deflection of the deflecting device and is formed by the second and third grids G2 and G3. The action of the prefocus lens that focuses more strongly in the vertical direction than in the horizontal direction becomes stronger, and the horizontal object point diameter with respect to the main lens due to the horizontally elongated groove 20 formed on the surface of the second grid G2 on the side of the third grid G3. And the effect of enlarging the horizontal divergence angle become stronger. Further, since the voltage of the fifth grid G51 increases together with the third grid G3 in accordance with the deflection of the deflecting device, the focusing is stronger in the horizontal direction than in the vertical direction formed by the third, fourth grids G3, G4 and the fifth grid G51. The action of the sub-lens becomes stronger. This suppresses the horizontal divergence angle of the electron beam, expands the vertical divergence angle, reduces the horizontal divergence angle expanded by the prefocus lens, and reduces the horizontal object point diameter with respect to the main lens. The effect is obtained. The electron beam focused by this sub-lens is formed by the fifth grids G51, G52, G53 because the voltage of the fifth grids G51, G53 rises as the deflector deflects.
The polar lens corrects the deflection aberration caused by the magnetic field generated by the deflecting device. Furthermore, the fifth grid G53 and the sixth
The main lens, which is finally formed by the grid G6 and focuses the electron beam on the phosphor screen, becomes weak because the voltage of the fifth grid G53 rises as the deflector deflects. As a result, as shown in FIG. 4, the beam spot 23 at the peripheral portion of the screen has a small horizontal bleeding and a relaxed laterally long shape, and the beam spot 23 at the peripheral portion of the conventional screen has horizontal bleeding. It is possible to solve the problem that characters or the like on the screen that are generated due to the occurrence or the oblong shape are difficult to see.

[0028]

EFFECT OF THE INVENTION An electron gun including a cathode and a plurality of electrodes arranged in the phosphor screen direction from the cathode is provided, and the cathode and the electrodes are used to generate an electron beam. A pre-focus lens for pre-focusing the electron beam, a sub-lens for further pre-focusing the electron beam pre-focused by the pre-focus lens, and an electron beam pre-focused by the pre-focus lens and the sub-lens finally a phosphor screen A main lens that converges on the top, and a dynamically changing quadrupole lens that corrects the deflection aberration generated by the magnetic field generated by the deflecting device is formed between the sub lens and the main lens by applying a dynamically changing voltage. In a color picture tube device, the vertical focusing of the prefocus lens is more than that of the horizontal focusing. The sub-lens forms a lens in which the horizontal focusing is stronger than the vertical focusing, and the strength of the prefocus lens, the sub-lens, and the main lens simultaneously changes due to the dynamic change of the quadrupole lens. As described above, the electrodes forming each lens are connected to the electrodes of the quadrupole lens to which a dynamically changing voltage is applied, and more specifically, the cathode and the cathode are arranged in the phosphor screen direction. First, second, third and fourth electrodes, three divided fifth electrodes and a sixth electrode
An electron gun comprising electrodes, its cathode and first,
A triode that generates an electron beam by the second electrode, a prefocus lens that prefocuses the electron beam from the triode by the second and third electrodes, a third electrode, a fourth electrode, and a fourth electrode that is adjacent to the fourth electrode. A sub-lens for further pre-focusing the electron beam pre-focused by the pre-focus lens by one of the five electrodes, a sixth electrode and a fifth electrode adjacent to the sixth electrode.
The electron beam pre-focused by the pre-focus lens and the sub-lens by one of the electrodes is dynamically changed to the main lens which finally focuses on the phosphor screen and one of the fifth electrodes adjacent to the fourth electrode. A color image is formed by applying a voltage, and by applying this voltage, a quadrupole lens is formed between the sub-lens and the main lens by the three electrodes of the fifth electrode to correct the deflection aberration caused by the magnetic field generated by the deflecting device. In the tube device, the prefocus lens forms a lens in which the vertical focusing is stronger than the horizontal focusing, the sub-lens forms a lens in which the horizontal focusing is stronger than the vertical focusing, and the quadrupole lens Adjacent to the third and sixth electrodes that form the prefocus lens, the sublens, and the main lens so that the strengths of the prefocus lens, the sublens, and the main lens change at the same time due to dynamic changes. When one of the fifth electrodes is connected to one of the fifth electrodes adjacent to the fourth electrode and to which a dynamically changing voltage is applied, the electron beam emitted from the electron gun is deflected by the deflecting device. When it goes to the center of the screen without being deflected, the electron beam from the triode part has a negative astigmatism that is stronger in the vertical direction than in the horizontal direction due to the focusing action stronger in the vertical direction than the horizontal direction of the prefocus lens. Due to the aberration, the object point diameter in the horizontal direction with respect to the main lens is reduced,
The horizontal divergence angle changes as if it had expanded. The electron beam focused by this prefocus lens is
The next sub-lens receives a stronger positive astigmatism in the horizontal direction than in the vertical direction due to the stronger focusing action in the horizontal direction than in the vertical direction, which suppresses the divergence angle in the horizontal direction of the electron beam, The divergence angle is increased.
Since the quadrupole lens is not formed in the electron beam focused by this sub lens, it is finally focused by the main lens, and the beam spot on the phosphor screen is
It has a slightly vertical shape.

On the other hand, when the electron beam is deflected to the peripheral portion of the screen by the deflecting device, the quadrupole lens dynamically changes due to the application of the dynamically changing voltage, and the action of the quadrupole lens The deflection aberration is corrected by. At the same time, the vertical focusing is stronger than the horizontal focusing, and the action of the prefocus lens is strengthened, and the horizontal object point diameter with respect to the main lens is further reduced as compared to when it is not deflected, and the horizontal divergence angle is expanded. Direction. Also, the sub-lens, which has a stronger horizontal focus than the vertical focus, becomes stronger,
The positive astigmatism that is stronger in the horizontal direction than in the vertical direction becomes larger, the effect of suppressing the divergence angle of the electron beam in the horizontal direction and increasing the divergence angle in the vertical direction becomes stronger, and the divergence angle magnified by the prefocus lens is increased. to shrink. After that, the electron beam is focused by the main lens, and the beam spot on the phosphor screen has a horizontal eccentric shape with less horizontal bleeding. As a result, it is possible to solve the problem that the conventional beam spot in the peripheral portion of the screen has horizontal bleeding or the characters are difficult to see due to the horizontally long shape.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electron gun of a color picture tube device which is an embodiment of the present invention.

FIG. 2 (a) is a diagram showing the structure of the second grid, and FIG. 2 (b) is a diagram showing the structure of the fourth grid.

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

FIG. 4 is a diagram for explaining the shape of a beam spot on the screen of the color picture tube device.

FIG. 5 is a diagram showing a configuration of a QPF type double focus type electron gun of a conventional color picture tube device.

FIG. 6 is a diagram for explaining the shape of a beam spot on the screen of a conventional in-line type color picture tube device.

FIG. 7 is a diagram for explaining the shape of a beam spot on a screen by the QPF type double focus type electron gun.

FIG. 8 is a diagram for explaining the shape of a beam spot on a screen by a conventional improved QPF type double focus type electron gun.

[Explanation of symbols]

 12 ... Phosphor screen 14 ... Electron gun 15 ... 3 Electron beam 17 ... Deflection device 19a, 19b, 19c ... Electron beam passage hole 20 ... Oblong groove 21a, 21b, 21c ... Electron beam passage hole 23 ... Beam spot G1 ... 1st Grid G2 ... Second grid G3 ... Third grid G4 ... Fourth grid G51, G52, G53 ... Three divided fifth grids G6 ... Sixth grid K ... Cathode

Claims (2)

[Claims] 1. An electron gun comprising a cathode and a plurality of electrodes arranged in the phosphor screen direction from the cathode, and a deflection device for generating horizontal and vertical deflection magnetic fields for deflecting an electron beam emitted from the electron gun. A three-pole part for generating an electron beam by the cathode and the plurality of electrodes, a prefocus lens for prefocusing the electron beam from the three pole part, and a subfocus for further prefocusing the electron beam prefocused by the prefocus lens lens,
The main lens that finally focuses the electron beam prefocused by the prefocus lens and the sublens on the phosphor screen, and the deflection between the sublens and the main lens by applying a dynamically changing voltage. In a color picture tube device that forms a dynamically changing quadrupole lens that corrects for deflection aberrations caused by the magnetic field generated by the device, the prefocus lens forms a lens in which the vertical focusing is stronger than the horizontal focusing. The sub-lens forms a lens in which the horizontal focusing is stronger than the vertical focusing, and the strengths of the prefocus lens, the sub-lens, and the main lens simultaneously change due to the dynamic change of the quadrupole lens. The electrodes forming each of these lenses are
A color picture tube device, which is connected to an electrode of a polar lens to which a dynamically changing voltage is applied. 2. An electron gun comprising a cathode and first, second, third and fourth electrodes arranged in the phosphor screen direction from the cathode, and three divided fifth electrodes and a sixth electrode, and A three-pole part for generating an electron beam by the cathode and the first and second electrodes is provided with a deflecting device for generating horizontal and vertical deflection magnetic fields for deflecting the electron beam emitted from the electron gun, and the second and third electrodes. Electron prefocused by the prefocus lens by one of the prefocus lens for prefocusing the electron beam from the triode by the electrode, the third and fourth electrodes and the fifth electrode adjacent to the fourth electrode The pre-focus lens and the sub-lens pre-focus by the sub-lens for further pre-focusing the beam, the sixth electrode and one of the fifth electrodes adjacent to the sixth electrode. A dynamically changing voltage is applied to one of the main lens and the fifth electrode adjacent to the fourth electrode to finally focus the generated electron beam on the phosphor screen, and the fifth voltage is applied by applying this voltage. In the color picture tube device, a three-electrode electrode forms a dynamically changing quadrupole lens between the sub-lens and the main lens to correct the deflection aberration generated by the magnetic field generated by the deflecting device. The focus lens forms a lens in which the vertical focusing is stronger than the horizontal focusing, the sub-lens forms a lens in which the horizontal focusing is stronger than the vertical focusing, and the sub-lens is formed by a dynamic change of the quadrupole lens. One of the third electrode and the fifth electrode adjacent to the sixth electrode forming each of the prefocus lens, the sublens and the main lens is changed to the first electrode so that the strength of the lenses changes simultaneously. A color picture tube device, characterized in that it is connected to one of the fifth electrodes to which a dynamically changing voltage is applied adjacent to the four electrodes.