JPH0388244A - Color picture tube and deflection device - Google Patents

Abstract

PURPOSE:To reduce deflection aberration and prevent deterioration of focus characteristics at peripheral parts of a face plate by disposing pairs of permanent magnets in the three-electron beam disposition direction and the direction forming an angle theta respectively with their polarity opposite to each other axially symmetrically to the center axis of a deflection device. CONSTITUTION:A pair of permanent magnets 28a, 28b, 50a, 50b, 60a-60d are disposed respectively at up, down, right and left positions and positions having a predetermined angle theta clockwise and counterclockwise horizontally to be axially symmetric to the center axis (Z-axis) of a deflection device 21 and to have opposite polarity to each other at a side end part 27 of an electron gun structural body of the deflection device 21. A pin-cushion shaped magnetic field is thus formed by the permanent magnets 28a, 28b, 50a, 50b, 60a-60d, so the magnetic field of the deflection device 21 compensates deflection aberration applied to an electron beam, and the focus characteristics at the peripheral parts of a face plate can be improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a color picture tube and its deflection device that improves the deflection aberration caused by the deflection magnetic field of the deflection device and improves focus characteristics. Regarding.

(Prior Art) Generally, a color picture tube has an envelope (1) consisting of a panel (1), a funnel (2) and a neck (2) as shown in FIG. ■
is formed, and a shadow mask (2) is placed opposite this phosphor screen (2).

In addition, there are three electron beams (B) and (G) inside the neck ■.
.

An electron gun assembly 0 that emits (R) is provided, and three electron beams (B) and (G) are emitted from this electron gun assembly 0.

(R) is a deflection device attached to the outside of the envelope ■! ! The structure is such that a color image is displayed on the phosphor screen (2) by scanning the phosphor screen (2) with deflection in the horizontal and vertical directions by (2). Said deflection device! As shown in FIG. 11, (2) has a pair of horizontal deflection coils (10) that deflect the three electron beams in the horizontal direction, and a pair of vertical deflection coils (11) that deflect the three electron beams in the vertical direction.

In the color picture tube, in order to display a correct image on the phosphor screen (2), three electron beams (B), (G) are required to cover the entire surface of the phosphor screen (2).

It is necessary to concentrate (R) correctly. Therefore, there is a so-called self-convergence type in-line color picture tube in which the electron gun assembly 0 is an in-line electron gun assembly and the deflection magnetic field formed by the deflection device (2) is a specific non-uniform magnetic field. It is known that the deflection magnetic field of this self-convergence type in-line color picture tube consists of a pincushion-shaped horizontal deflection magnetic field and a barrel-shaped vertical deflection magnetic field.

However, even if the magnetic field is configured as described above, in-line color picture tubes still suffer from coma aberration in which the convergence of the center beam (G) and the side beams (B) and (R) shifts at the periphery of one screen. .

In order to correct this coma aberration, a magnetic material that combines with the rear leakage magnetic field of the deflection device is arranged in the electron gun structure, as published in Japanese Patent Publication Nos. 51-26208 and 54-23208.
It is shown in the publication No. In addition, without using a magnetic material that couples with the rear leakage magnetic field of such a deflection device, by passing a current synchronized with the deflection current flowing through the vertical deflection coil to the electron gun structure side of the deflection device, Japanese Utility Model Publication No. 57-45748 discloses a device in which an auxiliary coil is added to form a strong pincushion-shaped magnetic field. However, even with such a color picture tube, the spot of the electron beam on the phosphor screen is still distorted according to its deflection. That is, as shown in FIG. 12, the spot (13) of the electron beam deflected by the uniform magnetic field forms a nearly perfect circle over the entire surface of the screen (14).

However, as shown in Fig. 13, the spot (13) of the electron beam deflected by the nonuniform magnetic field is
At the horizontal axis (X-axis) end of the electron beam (B), each electron beam (B) is distorted into a horizontally elongated ellipse, as shown in FIG. 14(a).
The upper halves of (G) and (R) receive the Lorentz force that presses them downward, and their lower halves press upward, resulting in an elliptical shape with the horizontal axis as its major axis. Further, at the end of the vertical axis (Y axis) of the screen (14), each electron beam (B
), (G), and the right half of (R) to the right.

In particular, the pair of side beams (B) and (R) are distorted into elliptical shapes with the long axis in the horizontal axis direction due to the Lorentz force that pushes the left half to the left. The magnitude of the force received by the electron beam (B) on the left side of the screen and the direction of the force received by the electron beam (R) on the right side of the screen are opposite, so the pair of side beams (B) at the end of the vertical axis ), (R) spots are shown in Figure 13 (
As shown in 13B) and (13R), the long axes are tilted in a direction that intersects with each other.As a result, the beam spot is deformed and tilted by the horizontal or vertical deflection magnetic fields (15) and (16), causing the periphery of the screen (14) The focus characteristics deteriorate significantly in some areas. Moreover, the deterioration of the focusing characteristics is a major cause of hindering the improvement of the performance of the electron gun assembly. Therefore.

To improve focus at the periphery of the screen (14).

Screen (14) Sacrificing focus in the center of the screen (
14) A compromise design that emphasizes uniformity of focus in the center and periphery is forced.

Furthermore, since the auxiliary coil of Japanese Utility Model Publication No. 57-45748 utilizes a current synchronized with the deflection current flowing through the vertical deflection coil, the following problem occurs. In other words, when an electron beam is deflected in the vertical axis direction, the electron beam is excessively deflected in the vertical axis direction on the electron gun assembly side of the deflection device due to the magnetic field generated in the horizontal direction of the horizontal thin clay, causing the neck of the funnel to They tend to collide with the inner walls, creating so-called neck shadows on the screen where the electron beams do not reach (areas where no light is emitted).

Furthermore, since this auxiliary coil has a structure in which a coil is wound around a magnetic material and a current is passed through the coil, it becomes expensive as a correction element and is difficult to reduce in price.

Deflection devices are often used with different impedances depending on the receiver of each set manufacturer.

The current flowing through the deflection coil varies depending on the difference in impedance. Therefore, in order to make the effect of the auxiliary coil appropriate for such a deflection device, it is necessary to change the specifications of the auxiliary coil in accordance with the impedance of the deflection coil, which results in a lack of mass productivity.

(Problems to be Solved by the Invention) As described above, conventionally, the in-line electron gun structure has an in-line type electron gun structure that emits three electron beams arranged in a row passing on the same horizontal plane, and the three electron beams are deflected by a pincushion horizontal deflection magnetic field. and a deflection device that forms a barrel-shaped vertical deflection magnetic field.
There are self-converging in-line color picture tubes that concentrate the light onto a phosphor screen. However, in this color picture tube, coma aberration occurs in which the convergence of the center beam and a pair of side beams deviates at the periphery of the screen. In order to correct this coma aberration, conventional methods have been to place a magnetic material in the electron gun body that combines with the leakage magnetic field at the rear of the deflection device, or to provide an auxiliary current that is synchronized with the vertical deflection current to the electron gun body side of the deflection device. Some have coils arranged. However, even with this configuration, the spot of the electron beam on the phosphor screen is distorted into a horizontally long ellipse with the long axis in the horizontal direction at the horizontal and vertical ends of the screen, especially at the vertical end. In this case, the spots of the pair of side beams are tilted in a direction that intersects with each other, significantly deteriorating the focusing characteristics at the periphery of one screen. This deterioration of the focus characteristics becomes a major cause of impeding the improvement of the performance of the electron gun assembly, and poses problems such as hindering the improvement of the focus characteristics over the entire screen.

This invention was made to solve the above problem, and reduces the distortion of the electron beam spot, that is, the deflection aberration, caused by the deflection magnetic field of the deflection device, and thereby prevents the deterioration of focus characteristics at the periphery of the screen. It is an object of the present invention to provide a color picture tube and its deflection device that prevent the above problems and have good focus characteristics over the entire screen.

(Structure of the Invention) (Means for Solving the Problem) The electron gun structure has an in-line electron gun structure that emits three electron beams arranged in a row, each consisting of a center beam and a pair of side beams and passing on the same plane. a first deflection coil that forms a mainly pincushion-shaped deflection magnetic field that deflects the three electron beams emitted from the phosphor screen onto a phosphor screen; and a mainly barrel-shaped deflection magnetic field that deflects the three electron beams in a direction perpendicular to the direction in which the three electron beams are arranged. In a color picture tube and its deflection device, the center of the deflection device is located on the path of three electron beams between the deflection device and the electron lens section of the electron gun assembly. Axisymmetric with respect to the axis and with opposite polarities, one pair is placed in the same direction as the three electron beams, and one pair is placed in the direction orthogonal to the three electron beams. A pair of magnetic fields are each arranged at positions rotated counterclockwise by an angle θ, and the strength and arrangement of the individual magnetic fields are such that they generate pincushion-shaped deflection magnetic fields that compensate for deflection aberrations caused by the deflection magnetic field formed by the second deflection coil. A color picture tube and a deflection device including a plurality of permanent magnets whose positions are set relative to each other.

(Function) As described above, a pincushion magnetic field is provided on the path of the three electron beams between the deflection device and the electron lens section of the electron gun assembly to compensate for the deflection aberration caused by the deflection magnetic field formed by the second deflection coil. If a pair of permanent magnets are placed in directions that are axially symmetrical with respect to the central axis of the deflection device and have opposite polarities so as to form an angle θ with the direction in which the three electron beams are arranged, then
The pincushion magnetic field formed by this permanent magnet exerts a Lorentz force on the electron beam in the direction perpendicular to the inclination of the pair of side beams due to the deflection aberration of the barrel-shaped deflection magnetic field of the second deflection coil, and as a result, the pair of side beams The tilt of the side beam can be corrected.

In addition, 3 points between the deflection device and the electron lens section of the electron gun assembly are
In order to generate a pincushion-shaped magnetic field on the path of the electron beam that compensates for the deflection aberration caused by the deflection magnetic field formed by the second deflection coil, the three When a permanent magnet is placed in a direction perpendicular to the arrangement direction of the electron beams, the pincushion-shaped magnetic field formed by this permanent magnet is in the opposite direction to the Lorentz force exerted on the third electron beam by the barrel-shaped deflection magnetic field of the second deflection coil. A Lorentz force is applied to the three electron beams to correct the ellipticalization of the electron beam caused by the barrel-shaped deflection magnetic field of the second deflection coil, and to strengthen the effect of correcting the inclination of the pair of side beams.

In this case, if the distance between the polarities of the permanent magnets arranged in the direction forming an angle θ with the arrangement direction of the three electron beams is made as small as possible within the range that allows the required magnetization strength to be obtained, the inclination of the pair of sub-beams can be further reduced. Correction can be made more effectively. Furthermore, if the distance between the polarities of the permanent magnets arranged in the direction orthogonal to the direction in which the three electron beams are arranged is made smaller than the distance in the direction in which the pair of side beams are arranged, an effective magnetic field can be formed in the electron beam passing region. .

The permanent magnets, which are arranged at an angle θ with the alignment direction of the three electron beams, form a wide and strong pincushion magnetic field in the side beam passage area, so the improvement effect on the deflection aberration of the side beam is This can be corrected more effectively than the pincushion-shaped magnetic field formed by permanent magnets arranged in a direction perpendicular to the arrangement direction of the pincushion magnetic field.

Furthermore, the pincushion-shaped magnetic field formed by the permanent magnets arranged at an angle θ with the direction in which the three electron beams are arranged reduces the amount of vertical deflection of the pair of side beams and improves the convergence, or coma aberration, at the periphery of the 61 screen. be able to.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Embodiment 1> First, an embodiment of a self-convergence type in-line color picture tube is shown. This color picture tube has a panel ω
The inner surface of the panel (1) has an envelope (■) consisting of a funnel (1) and a funnel (2), and a shadow mask (1) in which a large number of electron beam passage holes are formed. A phosphor screen (2) consisting of a three-color phosphor layer that emits red light is formed. In addition, an in-line electron gun assembly (20), which will be described later, is disposed within the neck ■ of the funnel ■, which emits three electron beams (B), (G), and (R) arranged in a line that pass on the same horizontal plane. . moreover,
The three electron beams (B), (G), (R) emitted from the electron gun assembly (20) are deflected horizontally and vertically to the outside of the boundary between the cone part ■ of the funnel ■ and the neck 0. Amount of deflection to scan the phosphor screen ■! (2
1) is installed. Said deflection device! (21) is.

Three electron beams (B), (G), (
This is a self-convergence system that concentrates R) on the phosphor screen. It has a horizontal deflection coil (23) and a pair of vertical deflection coils (25), which are wound, for example, around a core (24) and attached to the outside of the separator (22). A pair of horizontal deflection coils (
23) forms a mainly pincushion-shaped deflection magnetic field that deflects the three electron beams emitted from the electron gun assembly (20) in the horizontal direction (X-axis direction), and a pair of vertical deflection coils (25) 3. A mainly barrel-shaped deflection magnetic field is formed that deflects the three electron beams in a vertical direction (Y-axis direction) perpendicular to the direction in which the electron beams are arranged. By the way, what is meant by a mainly pincushion-type or mainly barrel-type deflection magnetic field?

Respectively, they collectively mean a pincushion-shaped deflection field and a barrel-shaped deflection field.

The color picture tube of this example is a self-convergence type in-line color picture tube, but as shown in FIG. one pair each at the top, bottom, left and right positions so that they are axially symmetrical with respect to the central axis (Z-axis) (generally coincides with the tube axis when installed in a color picture tube) and have opposite polarities. a pair of permanent magnets (28a) located at predetermined angles θ clockwise and counterclockwise with respect to the horizontal direction;
(28b) = (50a) - (50b), (60a)
, (60b), (60c), and (60d) are arranged. In this example, θ is set to about 40@. These permanent magnets (28a), (28b),
(50a).

(50b), (60a) = (60b) - (60c)
, (60d) is a cubic oxide magnet as shown in Fig. 3, and the distance between the magnetic poles at both ends is the length S ==
Permanent magnets (28
The surface magnetic flux density at the center of am in a) and (2ab) is 70
0 Gaugs/cd, permanent magnets placed on the left and right (50
The surface magnetic flux density at the center of the magnetic poles in a) and (50b) is 35
0 Gauss/aJ, permanent magnets (60a), (60b), (60c) placed in the θ direction = (60d
) The surface magnetic flux density at the center of the magnetic pole is 400Gautxs/
It is set to d.

By the way, in this way, a pair of permanent magnets (28a) - (28b) = (50a) - (50
b) * (60a)-(60b), (60c), (
60d) has the following effects.

■ Permanent magnets (60a) = (60b) arranged in pairs, axially symmetrical with respect to the central axis of the deflection device, with opposite polarities, and in a direction forming an angle θ with the arrangement direction of the three electron beams.
, (60cL (60d) is a pair of side beams (B) corresponding to the angle θ, as shown in FIGS. 4 and 6.
, (R) has a strong pincushion magnetic field (53
) to form. A pair of side beams (
The spots of B) and (R) are subjected to a Lorentz force that distorts them into an elliptical shape with the long axis in the direction perpendicular to the θ direction, which causes a phenomenon in which the spots of the pair of side beams are tilted based on the barrel-shaped deflection magnetic field (42). to correct.

■ In addition, a permanent magnet (28aL (2
8b) corresponds to the barrel-shaped deflection magnetic field (42) of the second deflection coil, as shown in FIGS. A strong pincushion magnetic field (43) is applied to the pincushion magnetic field, and three electron beams (8) pass through this pincushion magnetic field.

A Lorentz force is applied to (G) and (R) to distort the beam spot into an elliptical shape with the long axis in the vertical direction, and the horizontal direction of the beam spot based on the barrel-shaped vertical deflection magnetic field (42) is taken as the long axis. This corrects the phenomenon of elliptical formation and tilting of the spots of a pair of side beams.

In order to effectively correct the side beams (B) and (R), a pair of upper and lower permanent magnets (28a) are required.

It is preferable that the spacing S■ between the magnetic poles (28b) is smaller than the spacing in the arrangement direction of the pair of side beams.

■ Furthermore, these permanent magnets (28a), (28b
).

(50a), (50b), (60a), (60b
The beam spot correction effect by L (60c) and (60d) is obtained by synchronizing the deflection current flowing in the vertical deflection coil on the electron gun structure side of the deflection device, as disclosed in the above-mentioned Japanese Utility Model Publication No. 57-45748. Compared to a method that adds an auxiliary coil that conducts current, the correction means is simpler and smaller, can be configured at a lower cost, and is more easily mass-produced.In addition, in the case of an auxiliary coil, the magnetic field is changed by the deflection current flowing through the vertical deflection coil. Therefore, if an attempt is made to properly correct the beam spot shape near the vertical axis end of the screen using the auxiliary coil, the magnetic field becomes too weak in the middle of the vertical axis, making it impossible to sufficiently correct the beam spot shape. On the other hand, in order to properly correct the beam spot shape in the middle part of the vertical axis, a considerably strong magnetic field is required. In this case, due to the strong magnetic field, the beam spot shape near the end of the vertical axis is not only overcorrected and degraded, but also has an adverse effect on convergence characteristics. In other words, it is extremely difficult to properly correct the beam spot of the entire screen using the auxiliary coil, but the four pairs of permanent magnets (28a) and (28b).

(50a), (50b), (60a), (60b
), (60c), and (60d) each generate a steady magnetic field, so if the beam spot near the vertical axis end of the screen is optimally corrected, the beam spot in the middle can also be sufficiently corrected at the same time, and the screen The overall beam spot shape can be improved.

■ This color picture tube is capable of correction according to the deflection current of the deflection device using a magnetic field correction element installed at the bottom of the convergence cup, and corrects convergence, or coma aberration, at the periphery of the two screens, resulting in good performance over the entire screen. Convergence can be obtained. Especially in large color picture tubes with two large screens, from the center of the screen to the periphery.
Since uniformity of focus and convergence is required, an auxiliary coil that is difficult to adjust between the center and periphery of the screen is at a significant disadvantage, but the permanent magnet (28a) in this example
, (28b), (50a), (50b), (6
0a), (60b).

In (60c), (60d) this can be done advantageously.

■ Due to its structure, it is difficult to arbitrarily change the shape and size of the auxiliary coil to form the required magnetic field.
However, it is easy to make the whole thing larger.

Permanent magnet (28a), (28b), (50a),
(50b), (60a).

(60b), (60c), and (60d) can easily change the magnetic pole spacing, magnetization strength, shape, etc.
Moreover, the entire structure can be made compact. In addition, the placement position has a greater degree of freedom than the auxiliary coil; for example, it can be placed between the electron gun structure side end of the deflection device and the core. A good correction effect can be obtained.

<Example 2> In the above example, four pairs of permanent magnets were arranged around the end of the deflection device on the electron gun structure side. It may be located in the area, or may be provided independently apart from the deflection device.

FIGS. 7(a) and 7(b) show three independent cathodes (30) arranged in a row in the horizontal direction, first and second grids (31) for controlling electron emission from the cathodes (30), (
32), and a third electron beam forming section that accelerates and focuses the three electron beams emitted through the electron beam forming section. This is a pi-potential type electron gun structure consisting of an electron lens section consisting of fourth grids (33) and (34), and a convergence cup (37) attached to the fourth grid (34) constituting the electron lens section. A magnetic field control element consisting of magnetic materials (41a) and (41b) is provided at the bottom, and a magnetic field control element consisting of magnetic materials (41a) and (41b) is provided on the inner surface of the convergence cup (37), which is axially symmetrical and polarized with respect to the central axis (55) of the electron gun assembly (20). Four pairs of permanent magnets (1
28a), (128b)= (150a), (15
0b).

(160a), (160b), (160c), (
160d) as up, down, left and right.

It is arranged at a position rotated by θ clockwise and counterclockwise from the horizontal direction. In this case, the distance between the magnetic poles of the permanent magnets (128a) and (128b) distributed vertically is smaller than the distance Sg in the arrangement direction of the pair of side beams passing through the electron lens section in FIG. The surface magnetic flux density of the magnets (128a) and (128b) is.

Permanent magnets (
150a), (150b), (160a), (160
b), (160c).

Permanent magnets (150a), which are larger than the surface magnetic flux density of (160d) and arranged on the left and right sides and in the θ direction, (15
0b).

(160a), (160b), (160c), (
160d) is configured to form a pincushion-shaped magnetic field stronger than the magnetic field strength formed by 160d). These permanent magnets (128a).

(128b), (150a), (150b), (
160a), (160b), (160c).

The structure and arrangement of (160d) correspond to the arrangement of the permanent magnets in the first embodiment.

In this way, the permanent magnet (128a) is attached to the electron gun structure (20).
.

(128b), (150a), (150b), (
160a), (160b), (160c).

(160d), it is possible to obtain a color picture tube that produces the same effects as in the first embodiment.

In this embodiment, four pairs of permanent magnets are arranged inside the convergence cup, but these permanent magnets can also be arranged, for example, in a grid forming the main lens part of the electron gun assembly. However, in this case, when the pincushion-shaped magnetic field formed by the permanent magnet acts on the main lens of the electron gun structure, coma aberration occurs due to the side beam not passing through the center of the main lens. It is desirable that the electron lens be placed in a position where the magnetic field does not reach the electron lens section.

Note that the present invention is not limited to the electron gun structures shown in the above embodiments, but can be applied to color picture tubes equipped with various other electron gun structures, and in particular, a permanent magnet is disposed in the electron gun structure. The same applies to the case. Further, the magnetic field control element is not limited to the coma aberration correction element of each of the embodiments described above, but can be selected from various shapes depending on the size and system of the color picture tube and deflection device.

For example, as shown in FIGS. 9(a) and 9(b), three independent cathodes (30) arranged in a row in the horizontal direction and electron beams R, G, and B emitted from these cathodes (30) are The first thing to control. An electron beam forming section consisting of a second grid (31) and (32), and a third electron beam forming section that accelerates and focuses the three electron beams R, G, and B emitted through this electron beam forming section.
．． 4th. Fifth. 6th Grid (33).

(34)? It is also possible to have an electron gun assembly consisting of an electron lens section consisting of (35) and (36). A convergence cup (
Magnetic material (141a), (141b) at the bottom of 137)
At the same time, a pair of permanent magnets (228a), (228b), (250a) are provided on the inner surface of the convergence cup (137), respectively on the upper, lower, left and right sides.
), (250b) and a pair of permanent magnets (260a
), (260c)-(260b), and (260d) can also be arranged. In this case as well, a color picture tube having the same effects as in the above-mentioned embodiments can be obtained.

〔Effect of the invention〕

To the electron gun structure side end of the deflection device that forms a deflection magnetic field that deflects three electron beams arranged in a row passing on the same plane in the arrangement direction and the direction orthogonal to the arrangement direction or the main lens part of the electron gun structure. When pairs of permanent magnets forming pincushion-shaped magnetic fields are placed near the electrodes located on the phosphor, the pincushion-shaped magnetic fields formed by these permanent magnets reduce the deflection aberration caused by the magnetic field of the deflection device on the electron beam. It is possible to correct this and improve the focus characteristics at the periphery of the screen.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a self-convergence type in-line color picture tube according to the present invention, Fig. 2 is a perspective view of a deflection device which is the main part of Fig. 1, and Fig. 3 is a perspective view showing the shape of a permanent magnet. Figure, Figure 4. 5 and 6 are diagrams for explaining the effect that the permanent magnet attached to the color picture tube according to the present invention has on the electron beam spot, and FIG. A schematic diagram of the gun, Figure 10 is a configuration diagram of a conventional self-convergence type in-line color picture tube,
FIG. 11 is a perspective view showing the configuration of a deflection device attached to the color picture tube, FIG. 12 is an explanatory diagram of the spot shape of an electron beam deflected by the uniform magnetic field of the deflection device, and FIG. 13
The figure is an explanatory diagram of the spot shape of an electron beam deflected by the nonuniform magnetic field of the deflection device, and Figures 14 (a) and (b) are the effects of the pincushion-shaped horizontal deflection magnetic field and the barrel-shaped vertical deflection magnetic field, respectively, on the electron beam. FIG. 5... Fluorescent screen 20... Electron gun structure 2
DESCRIPTION OF SYMBOLS 1... Deflection device 23... Horizontal deflection coil 24... Core 25... Vertical deflection coil 27... Electron gun structure side end 28a of the deflection device,
28b, 128a, 128b, 228a, 228b - a pair of upper and lower permanent magnets 31...first grid 32...second grid 33...third grid 34...fourth grid 35...fifth grid 36...Sixth grid 37...Convergence cups 39a, 39b...Center beam passage hole 40a
~40d...Side beam passing holes 41a, 41b, 1
41a, 141b - Magnetic body 42...Barrel-shaped vertical deflection magnetic field 43...Pincushion-shaped magnetic field 50a, 50b, 150a, 150b, 250a, 25 formed by a pair of upper and lower permanent magnets
0b-Pair of left and right permanent magnets 51...pincushion-shaped horizontal deflection magnetic field 52...pincushion-shaped magnetic field 53 formed by a pair of left and right permanent magnets...magnetic field B formed between the permanent magnets in the θ direction
. R...Pair of side beams G...Center beam

Claims (2)

[Claims] (1) It has an electron beam forming part that forms three electron beams consisting of a center beam and a pair of side beams, and an electron lens part that focuses the three electron beams, and emits three electron beams arranged in a row that pass on the same plane. an in-line electron gun structure; a first deflection coil that forms a mainly pincushion-shaped deflection magnetic field that deflects the three electron beams in the direction in which they are arranged; and a mainly barrel-shaped deflection coil that deflects the three electron beams in a direction perpendicular to the direction in which they are arranged; a second forming a deflection magnetic field;
a deflection device including a deflection coil; and a deflection device arranged on the path of the three electron beams between the deflection device and the electron lens section of the electron gun assembly in response to the deflection magnetic field formed by the second deflection coil. a pair of electron beams axially symmetrical with respect to the central axis and having opposite polarities in the same direction as the arrangement direction of the three electron beams and in a direction orthogonal to the arrangement direction of the three electron beams, respectively;
Axisymmetrically with respect to the central axis in a direction rotated by an acute angle θ clockwise with respect to the arrangement direction of the three electron beams, and in a direction rotated by an acute angle θ counterclockwise with respect to the arrangement direction of the three electron beams, respectively. A plurality of permanent magnets are arranged in pairs, and the strengths and arrangement positions of the respective generated magnetic fields are mutually set so as to generate a pincushion-shaped magnetic field that compensates for the deflection aberration caused by the deflection magnetic field formed by the second deflection coil. A color picture tube characterized by having a magnet. (2) It is attached to a color picture tube that deflects and scans the three electron beams emitted from the in-line electron gun structure onto a phosphor screen and reproduces images, and is mainly a pincushion that deflects the three electron beams in the direction in which they are arranged. A deflection device comprising: a first deflection coil that forms a shaped deflection magnetic field; and a second deflection coil that mainly forms a barrel-shaped deflection magnetic field that deflects the three electron beams in a direction perpendicular to the direction in which the three electron beams are arranged; On the path of the three electron beams on the electron gun assembly side, a beam is placed on the path of the three electron beams on the electron gun assembly side in response to the deflection magnetic field formed by the deflection device, and is axially symmetrical with respect to the central axis of the deflection device and has opposite polarity and is the same as the arrangement direction of the three electron beams. one pair each in a direction perpendicular to the direction and the arrangement direction of the three electron beams, and a direction rotated by an acute angle θ clockwise with respect to the arrangement direction of the three electron beams, and counterclockwise with respect to the arrangement direction of the three electron beams. A pair of pincushion magnetic fields are arranged in pairs axially symmetrically with respect to the central axis in a direction rotated by an acute angle θ, and each generates a pincushion-shaped magnetic field that compensates for the deflection aberration caused by the deflection magnetic field formed by the second deflection coil. A deflection device comprising a plurality of permanent magnets whose magnetic field strengths and arrangement positions are mutually set.