JPH0278138A - Color television picture tube and deflection device - Google Patents

Abstract

PURPOSE:To decrease deflecting aberration so as to prevent deterioration of focusing properties in the periphery of a picture by placing permanent magnets on the way of three electron beam routes. CONSTITUTION:While their polarity being set to be in reverse, a pair of permanent magnets 28a, 28b having magnetic polar in the both ends are placed up and down-sides of a side end 27 of an electron gun composing body of a deflecting apparatus 21. By setting like this, the magnets 28a, 28b, corresponding to a barrel type perpendicularly deflecting magnetic field 42, form an intensive pin cushion type magnetic field 43 in an area three electron beams (B), (G), (R) passing. Formation of an ellipse having the major axis in horizontal direction of a beam spot depending on the magnetic field 42 and declining phenomenon of spots of a pair of side beams are corrected. Besides, correction corresponding to deflecting current of an apparatus is carried out by a magnetic field correcting device installed in the bottom of a convergence cup. Lorentz effect of moving side beams (B), (R) toward center beam (G) is caused by the magnetic field 43.

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 deflection aberration caused by the deflection magnetic field of the deflection device and improves focus characteristics. Regarding.

(Prior Art) In general, a color picture tube has an envelope (3) consisting of a panel (1) and a funnel (2), as shown in FIG. A phosphor screen (5) consisting of a three-color phosphor layer that emits blue, green, and red light is placed on the inner surface of the panel (1), facing the shadow mask (4) in which a large number of electron beam passage holes are formed. is formed. Also, in the neck (6) of the funnel (2) there is a 3'8
An electron gun structure (7) that emits quintuplet beams (B), (G), and (R) is provided, and this "electron gun structure (7)"
Three electron beams are emitted from (B) and (G).

(R) to the cone (8) of the funnel (2) and the neck (
The phosphor screen (5) is deflected horizontally and vertically by a deflection device (9) mounted outside the boundary with the phosphor screen (5).
) by scanning this phosphor screen (5〉
The structure is such that a color image is displayed on top.

As shown in FIG. 17, the deflection device (9) consists of a pair of horizontal deflection coils (l
O) and a pair of vertical deflection coils (1
■).

In the color picture tube, in order to display a correct image on the phosphor screen (5), three electron beams (B) are applied to the entire surface of the phosphor screen (5).

It is necessary to correctly concentrate (G) and (R).

Therefore, the center beam (G
) and a pair of side beams (B) and (R), three electron beams (B) arranged in a row passing on the same plane.

CG), (R), and by taking advantage of the characteristics of this inline electron gun structure,
By making the deflection magnetic field formed by the deflection device (9) a specific non-uniform magnetic field, the three electron beams (B), (G), (R) are concentrated over the entire surface of the phosphor screen (5). There is a self-convergence type in-line color picture tube. The deflection magnetic field of this self-convergence type in-line color picture tube is, for example, for a color picture tube that emits three electron beams (B), (G), and (R) arranged in a row passing on the same horizontal plane. is a pincushion-shaped horizontal deflection magnetic field and 2
It is known that the deflection field is composed of a barrel-shaped vertical deflection magnetic field. By creating such a magnetic field, three electron beams (B), (G), arranged in a row passing on the same horizontal plane
(lυ can be concentrated at one point on the phosphor screen (5).

However, even if the magnetic field is configured as described above, in-line color picture tubes still suffer from comatic aberration in which the convergence of the center beam (G) and the side beams (B) and (R) shifts at the periphery of the 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.
In addition, without using a magnetic material that couples with the rear leakage magnetic field of such a deflection device, a current synchronized with the deflection current flowing through the vertical deflection coil is applied to the electron gun assembly side of the deflection device. A model with an auxiliary coil that creates a strong pincushion-shaped magnetic field by flowing the current was developed in 1973.
It is disclosed in Japanese Patent No. 7-45748.

However, even if the color picture tube is constructed in this way, the spot of the electron beam on the phosphor screen will still be distorted according to its deflection. That is, as shown in Fig. 18, the spot (13) of the electron beam deflected by the uniform magnetic field becomes almost a perfect circle over the entire screen (■4), but as shown in Fig. 19, the spot (13) of the electron beam deflected by the uniform magnetic field becomes almost a perfect circle. The spot (13) of the electron beam deflected by the screen (
14), the pincushion horizontal deflection magnetic field (15) causes the top of each electron beam (B), (G), (R) to Under the influence of the Lorentz force, which presses one half downward and the lower half upward, it is distorted into a horizontally elongated ellipse with its long axis in the horizontal direction. Also, at the end of the vertical axis (Y axis) of the screen (14), the 20th
As shown in Figure (b), the barrel-shaped vertical deflection magnetic field (16
), each electron beam (B), (G), (R
) is distorted into a horizontally elongated ellipse with its long axis in the horizontal axis direction due to the Lorentz force that pushes the right half of the shape to the right and the left half to the left. In particular, regarding the pair of side beams (B) and (R), the magnitude of the force received on the left and right sides of the beams is different,
In addition, since the direction of the force received by the electron beam (B) on the left side of the screen and the electron beam (R) on the right side of the screen is opposite, a pair of side beams (B) and (R) at the end of the vertical axis
The spots are (13B) and (13R) in Figure 19.
tilt in directions that intersect with each other as shown in . As a result, due to the deformation and inclination of the beam spot due to the horizontal or vertical deflection magnetic fields (15) and (1B), the focusing characteristics in the peripheral area of the screen (14) are significantly deteriorated. Moreover, the deterioration of the focusing characteristics is a major cause of hindering the improvement of the performance of the electron gun assembly.

Therefore, in order to improve the focus at the periphery of the screen (14), a compromise is made that emphasizes uniformity of focus at the center and periphery of the screen (14) at the expense of focusing at the center of the screen (14). This has forced us to create a new design.

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 on the horizontal axis, 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).

Further, 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. Further, the deflection device is often used with its impedance changed depending on the receiver of each set manufacturer, and the current flowing through the deflection coil varies depending on the difference in impedance. therefore,
In order to make the action 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 childbirth properties.

(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 devices have coils arranged, but even with this configuration, the spot of the electron beam on the phosphor screen is a horizontally long ellipse with the long axis in the horizontal direction at the horizontal and vertical ends of the screen. In particular, at the end of the vertical axis, 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 the 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 Problems) An in-line electron gun structure includes 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. Released from
a first deflection coil that mainly forms a pincushion-shaped deflection magnetic field that deflects the three electron beams in the direction in which the three electron beams are arranged; In a color picture tube equipped with a deflection device having two deflection coils and its deflection device, a path of three electron beams between the deflection device and an electron lens section of an electron gun assembly that focuses the three electron beams on a phosphor screen. The strength and arrangement position of each generated magnetic field are adjusted 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 and statically focuses the three electron beams. A plurality of permanent magnets are provided which are mutually set.

In addition, in a similar color picture tube and its deflection device, there is a
On the path of the electron beam, a pair are arranged 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, axially symmetrical with respect to the central axis of the deflection device and with opposite polarities, A plurality of permanent magnets are provided in which the strength and arrangement position of each generated magnetic field are mutually set so as to generate a pincushion-shaped deflection magnetic field that compensates for the deflection aberration caused by the deflection magnetic field formed by the second deflection coil. Ta.

Furthermore, in a similar color picture tube, in addition to the permanent magnet, coma aberration correcting means made of a magnetic material that combines with the rear leakage magnetic field of the deflection device is provided.

Furthermore, in the same direction as the arrangement direction of the 3 electron beams and in the 3
Among the permanent magnets arranged in the direction perpendicular to the arrangement direction of the electron beams, the spacing between the magnetic poles of the individual permanent magnets arranged in the direction perpendicular to the arrangement direction of the three lightning beams is determined by the arrangement of the pair of side beams. It is smaller than the direction spacing.

(Function) As described above, the deflection aberration due to the deflection magnetic field formed by the second deflection coil on the path of the three electron beams between the deflection device and the electron lens part of the electron gun assembly is compensated for, and the deflection aberration of the three electron beams is compensated for. When a permanent magnet is arranged to generate a pincushion-shaped magnetic field that concentrates the electron beam, the pincushion-shaped magnetic field generated by this permanent magnet is opposite to the Lorentz force of the barrel-shaped deflection magnetic field of the second deflection coil that acts on the three electron beams. A directional Lorentz force can be exerted on the three electron beams to correct the ellipticalization of the electron beam and the tilt of the pair of side beams caused by the barrel-shaped deflection magnetic field of the second deflection coil.

In addition, 3 points between the deflection device and the electron lens section of the electron gun assembly are
Three electron beams are axially symmetrical with respect to the central axis of the deflection device and have opposite polarities so as 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. When a pair of permanent magnets is arranged in the same direction as the beam arrangement direction and in a direction perpendicular to the arrangement direction of the three electron beams, a pincushion-shaped magnetic field is formed by the permanent magnets arranged in the direction perpendicular to the arrangement direction of the three electron beams. In addition to the action of , a magnetic field is formed between the magnetic poles of adjacent permanent magnets that exerts a Lorentz force on the pair of side beams in the opposite direction to the Lorentz force of the barrel-shaped deflection magnetic field of the second deflection coil that acts on the pair of side beams, The inclination of the pair of side beams can be corrected more effectively.

In any color picture tube, when a magnetic field control element that couples with the rear leakage magnetic field of the deflection device is used together with the permanent magnet, in addition to the effect of the permanent magnet, the magnetic field control element improves the convergence of the entire screen. be able to.

Furthermore, if the distance between the magnetic poles of the permanent magnets arranged in the direction perpendicular 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. .

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

Embodiment 1 FIG. 1 shows an embodiment of a self-convergence type in-line color picture tube. This color picture tube has an envelope (3) consisting of a panel (1) and a funnel (2), and a shadow mask (3) with a large number of electron beam passage holes attached to the inside of the panel (1). A phosphor screen (5) consisting of a three-color phosphor layer that emits blue, green, and red light is formed on the inner surface of the panel (1) opposite to 4). In addition, three electron beams (B), (G) are arranged in a line passing on the same horizontal plane inside the neck (6) of the funnel (2).
, (R), which will be described later, is provided. In addition, funnel (2
) on the outside of the boundary between the cone part (8) and the neck (6),
Three electron beams (
A deflection device (21) is installed that deflects B), (G), and (R) horizontally and vertically to scan the phosphor screen (5).

The deflection device (21) is of a self-convergence type that focuses the three electron beams (B), (G), and (R) on the phosphor screen (5) using a non-uniform magnetic field, and is, for example, wound in a saddle shape. The separator (
A pair of horizontal deflection coils (23) are mounted symmetrically up and down (in the Y-axis direction) inside the separator (22), and a pair of vertical deflection coils (23) are wound around a core (24) and mounted on the outside of the separator (22), for example. and a deflection coil (25). A pair of horizontal deflection coils (23) of the deflection device (21) mainly generates a 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). The pair of vertical deflection coils (25)
A mainly barrel-shaped deflection magnetic field is formed that deflects the electron beam in the vertical direction (Y-axis direction) perpendicular to the direction in which the electron beam is arranged. Note that the term "mainly pincushion-shaped deflection magnetic field" and "mainly barrel-type deflection magnetic field" as used herein means that they are collectively a pincushion-type deflection magnetic field and a barrel-type deflection magnetic field, respectively.

Further, in the color picture tube of this example, as shown in FIG.
7), the central axis (Z-axis) of the deflection device (21) (generally, when attached to a color picture tube, it coincides with the tube axis)
A pair of permanent magnets (28a) axially symmetrical and above and below
, (28b) are attached. This permanent magnet (2
8a) and (28b) are cubic oxide magnets, as shown in Figure 3, and the distance (length) between the magnetic poles at both ends is
Smm 6 +n+s, thickness 1mm 3mm, width D
It is formed to a size of about a+ -3.5+am, and the surface magnetic flux density at the center of the magnetic pole is about 1500 Gauss/cJ, and the upper and lower permanent magnets (28a) and (28b) are arranged so that their polarities are opposite. .

Furthermore, the electron gun assembly (20) of the color picture tube in this example is as follows:
As shown in FIG. 4, there are three independent cathodes (30) arranged in a row in the horizontal direction, and first and second grids (31) for controlling electron emission from the cathodes (30).

(32) and three electron beams (B) and (G) emitted from this electron beam forming section.
.

The third to sixth grids (33) that accelerate and focus (R)
(36), and a convergence cup (37) is attached to the sixth grid (36). Note that (3g) is a heater that heats the cathode (30). The first and second electron gun structures (20)
, 4th grid (31), (32), (34)
is a plate-shaped integral structure in which three electron beam passing holes corresponding to three cathodes (30) are formed, and third, fifth,
The sixth grids (33), (35), and (3B) each consist of a cylindrical electrode having an integral structure in which three electron beam passage holes are formed.

In particular, each grid (33) to (3) constituting the electronic lens section
The electron beam passing hole B) is located in the above-mentioned - as shown in FIG.
Center beam passage hole (corresponding to the arrangement of the pair of permanent magnets)
Not only 39a), (39b) but also a pair of side beam passing holes (40a), (40b), (40c)
, (40d) are also coaxial, and the interval between the side beam passing holes, that is, the interval Sg in the arrangement direction of the pair of side beams passing through the main lens part is determined by the permanent magnet (40d) of the above-mentioned size.
Sa+=6 mm), it is approximately 6.6 mm. Furthermore, a magnetic field control element for correcting coma aberration consisting of magnetic bodies (41a) and (41b) that combines with the rear leakage magnetic field of the deflection device is installed around the side beam passage hole at the bottom of the base cup (39). It is being

By the way, as mentioned above, a pair of permanent magnets (28a) and (28b) having both ends as magnetic poles are placed above and below the electron gun assembly side end (27) of the deflection device (21) so that the polarities are opposite to each other. When placed, it has the following effects.

■ Permanent magnets (2B
a) , (2gb) corresponds to the barrel-shaped vertical deflection magnetic field (42) of the vertical deflection coil, as shown in FIG.
A strong pincushion-shaped magnetic field (43) is formed in the region through which the three electron beams (B), (G), and (R) pass. Therefore, three electron beams (B) reach the phosphor screen through this pincushion-shaped magnetic field (43),
(G).

The spot (R) receives a Lorentz force that is distorted into an ellipse with the long axis in the vertical direction, which is opposite to the Lorentz force received from the barrel-shaped vertical deflection magnetic field (42), and is based on the barrel-shaped vertical deflection magnetic field (42). This corrects the phenomenon in which the beam spot becomes oval with its long axis in the horizontal direction and the spots of a pair of side beams are tilted.

The beam spot correction effect by this pair of permanent magnets (28a) and (28b)
As disclosed in Japanese Patent No. 48, the correction means is simpler and smaller than the one in which an auxiliary coil is added to the side of the electron gun side body of the deflection device for passing a current in synchronization with the deflection current flowing through the vertical deflection coil. It can be constructed at low cost and is highly suitable for mass production.

In addition, in the case of an auxiliary coil, the magnetic field changes depending on the deflection current flowing through the vertical deflection coil, so if you try to properly correct the beam spot shape near the vertical axis end of the screen with the auxiliary coil, the magnetic field will change in the middle of the vertical axis. becomes too weak and the beam spot shape cannot be sufficiently corrected. 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 for the entire screen with the auxiliary coil.
The pair of permanent magnets (28a) and (28b) constantly generate a 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. It is possible to improve the beam spot shape over the entire screen.

■ This color picture tube has a convergence cup (37
) can perform correction according to the deflection current of the deflection device, and can correct convergence at the periphery of the screen, that is, coma aberration, to obtain good convergence over the entire screen. Particularly in large color picture tubes with large screen sizes, uniformity of focus and convergence is required from the center of the screen to the periphery, so auxiliary coils that are difficult to adjust between the center and periphery of the screen are at a significant disadvantage. , the permanent magnet (28a) in this example
, (28b), this can be done advantageously.

■ The strong pincushion-shaped magnetic field (43) generated by the pair of permanent magnets (28a) and (28b) is shown by the arrow (
44).

As shown in (45), a pair of side beams (B),
(R) exerts a Lorentz force that moves them toward the center beam (G). Therefore, this permanent magnet (2
By appropriately setting the magnetization strength of 8a) and (28b), three electron beams (I3) , , (G) , (
R) can be provided with a static concentration function to concentrate R) at a point on the center of the phosphor screen.

In the conventional electron gun assembly, these three electron beams (B), (G), and (R) are statically concentrated on two opposing grids (35a) that constitute the main lens, as shown in FIG.

Regarding (Ha), the side beam passing holes of the other grid (3tia) are eccentrically arranged outwardly, that is, in the direction away from the center beam passing hole, with respect to the side beam passing holes of one grid (35a), and the opposing grid ( 3
Electrostatic lens (4) formed between (5a) and (36a)
6) is made asymmetric, or as shown in Figure 9,
Three electron beams (B) are formed by tilting the electrostatic lens (46) formed between two opposing grids (34b) and (35b) with respect to the side beams (B) and (R).

(G) and (R) are concentrated at one point on the phosphor screen. Therefore, such a conventional static convergence method requires two types of electrodes with different shapes.

However, as mentioned above, a pair of permanent magnets (28a).

(28b), this permanent magnet (28a),
Due to the electron beam concentration function of (28b), there is no need for the electron gun structure to have a static convergence function.
As shown in FIGS. 4 and 5, the side beam passing holes of each grid (33) to (3B) constituting the main lens are formed coaxially to form three electron beams CB), (G),
It is possible to adopt a structure in which (R) is not concentrated on the phosphor screen, for example, a structure in which three electron beams (B), (G), and (R) are emitted in parallel. In such an electron gun structure, the grid can be manufactured at a lower cost and the assembly accuracy of the electron gun structure can be improved compared to a conventional electron gun structure in which the electrostatic lens is asymmetrical or tilted.

In addition, a pair of permanent magnets (28a) and (28
b) By appropriately selecting the size, arrangement, intensity, etc., three electron beams can be emitted from the electron gun structure not only in parallel to each other, but also in an inclined state toward the phosphor screen. It can also be applied when

■ A strong pincushion-shaped magnetic field (43) formed by a pair of permanent magnets (28a) and (28b)
As shown by arrows (47) and (4g) in Figure O, a Lorentz force is exerted that distorts the electron beam spot into an elliptical shape with the long axis in the vertical direction even at the center of the screen.

In conventional electron gun structures, the beam spot is distorted at the center of the screen in order to compensate for the distortion of the beam spot at the periphery of the screen into a horizontally elongated ellipse with the long axis in the horizontal direction due to the barrel-shaped vertical deflection magnetic field of the deflection device. There is one that has an elliptical shape with its long axis in the vertical direction. This is generally achieved by configuring the electron gun structure to consist of a non-rotationally symmetric lens with different focusing strengths in the vertical and horizontal directions, but the electrodes that make up this non-rotationally symmetric lens are made of ordinary electrodes. The structure is more complex than that of the previous model, and high processing precision is required, making the electron gun assembly expensive.

However, the beam spot shape at the center of the screen created by the permanent magnets (28a) and (28b) itself means that it has a non-rotationally symmetric lens function, and unlike conventional electron gun structures, the beam spot shape has a non-rotationally symmetric lens function. There is no need to hold it,
Therefore, all the electrodes of the electron gun assembly can be formed of simple electrodes forming a rotationally symmetric lens, making it possible to reduce the cost of the electron gun assembly and improve its reliability.

■ Due to its structure, it is difficult to arbitrarily change the shape and size of the auxiliary coil to form the required magnetic field.
The whole can easily be enlarged. However, the permanent magnet (28a)
, (28b), the magnetic pole spacing, magnetization strength, shape, etc. can be easily changed, and 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 The color picture tube of this example is a self-convergence type in-line color picture tube similar to the color picture tube of Example 1, but as shown in FIG.
1), a pair of permanent magnets (28a) are provided on the upper, lower, left and right sides of the electron gun structure side end (27) so as to be axially symmetrical with respect to the central axis of the deflection device (21) and have opposite polarities.

(28b), (50a), and (50b) are arranged. These permanent magnets (28a), (2&b
), (50a), and (50b) are cubic oxide magnets similar to the permanent magnets of Example 1, but the surfaces of the central portions of the magnetic poles of the permanent magnets (28a) and (28b) arranged above and below While the magnetic flux density is 1500 Gauss/c+#, permanent magnets (50a) placed on the left and right,
The surface magnetic flux density at the center of the magnetic pole (50b) is 1300
It is set to Gauss/cj and less.

By the way, in this way, a pair of permanent magnets (2
8a), (28b), (50a), (50
Placing b) has the following effects.

That is, a pair of permanent magnets (28a) arranged above and below
, (28b) exhibits the same effects as those of the first embodiment. In other words, this pair of permanent magnets (28a).

(28b) forms a strong pincushion-shaped magnetic field in response to the barrel-shaped vertical deflection magnetic field of the vertical deflection coil (25), and reverses the Lorentz force received from the barrel-shaped vertical deflection magnetic field to vertically deflect the spot of the electron beam. It exerts a Lorentz force that distorts the beam spot into an ellipse with the long axis in the direction, and corrects the phenomenon of the beam spot becoming oval with the long axis in the horizontal direction and the tilting of the spots of the pair of side beams due to the vertical deflection magnetic field.

On the other hand, a pair of permanent magnets <50a) placed on the left and right.

(50b) forms a pincushion-shaped magnetic field (52) in the same direction as the pincushion-shaped horizontal deflection magnetic field (51), as shown in FIG. At the same time each permanent magnet (28a).

(28b), (50a), (50b) are arranged so that their polarities are opposite, so as shown in Fig. 13, a pair of permanent magnets (50a), (50b)
are adjacent permanent magnets (28a) and (2sb), respectively.
A magnetic field (53) is also formed between the magnetic poles. This magnetic field (
53) is a pair of side beams (B).

A pair of side beams (B) based on the barrel-shaped vertical deflection magnetic field.

To more effectively correct the inclination of the spot (R).

The magnetic field (5
In order to make the effect of 3) effective, the distance between the magnetic poles of the upper and lower pair of permanent magnets (28a) and (28b) is 5I11.
It is preferable that Sg be smaller than the spacing Sg between the pair of side beams in the arrangement direction. However, as mentioned above, the pincushion-shaped magnetic field (43) formed by the upper and lower permanent magnets (28a) and (28b)
, (R) toward the center beam (G), the pincushion-shaped magnetic field (52) formed by the left and right permanent magnets (50a), (50b) acts to bring the pair of side beams (B), (R) closer to the center beam (G). ) away from the center beam (G), in combination with the electron gun assembly that emits parallel beams like the color picture tube of Example 1, a phosphor screen is attached to the pair of side beams. It is best to combine it with an electron gun structure that tilts toward the center.

Furthermore, regarding coma aberration, similarly to the color picture tube of Example 1, a magnetic field control element provided in the electron gun structure corrects convergence in the peripheral area of the screen, making it possible to provide a color picture tube free of coma aberration.

Furthermore, the color picture tube in this example also has each permanent magnet (28a).
, (28b), (50a), and (50b), by changing the spacing between the magnetic poles, magnetization strength, shape, etc., the required magnetic field can be easily formed, and the entire structure can be made compact. can. Further, there is a large degree of freedom in its placement position; for example, by placing it between the electron gun structure side end of the deflection device and the core, an extremely good correction effect can be obtained.

Example 3 In Examples 1 and 2, a pair of permanent magnets were arranged above and below the electron gun structure side end of the deflection device, or on the top, bottom, left and right sides of the deflection device. It is sufficient that it is located in the electron beam passing region, or it may be provided independently apart from the deflection device.

FIG. 14 shows the electron gun assembly (20), three independent cathodes (30) arranged in a row in the horizontal direction, and the cathodes (30).
) for controlling electron emission from the first and second grids (31
), (32), and an electron lens section consisting of third and fourth grids (33) and (34) that accelerate and focus the three electron beams emitted through the electron beam forming section. This is a pi-potential type electron gun structure consisting of a fourth grid (34
) A magnetic material (41a) is placed around the side beam passage hole at the bottom of the convergence cup (37) attached to the
(41b) and providing a magnetic field control element consisting of
A pair of permanent magnets (28a) are placed on the inner surface of the convergence cup (37) so that they are axially symmetrical with respect to the central axis (55) of the electron gun assembly (20) and have opposite polarities.
(28b) are arranged one above the other, and each permanent magnet (
The spacing between the magnetic poles 28a) and (28b) is smaller than the spacing in the arrangement direction of the pair of side beams passing through the electron lens section. This permanent magnet (28a).

The structure and arrangement of (28b) correspond to the arrangement of the permanent magnets in the first embodiment.

Further, FIG. 15 shows an electron gun assembly (20) having the same structure, in which a magnetic field control element made of magnetic materials (41a) and (41b) is provided at the bottom of the convergence cup (37), and the convergence cup (37) A pair of permanent magnets (2
8a), (28b), (50a), (50
b) are arranged vertically and horizontally. In this case, the distance between the magnetic poles of the permanent magnets (2+!a) and (28b) arranged above and below is smaller than the distance in the arrangement direction of the pair of side beams passing through the electron lens section. Also, this permanent magnet (
The surface magnetic flux densities of 28a) and (28b) are permanent magnets (50a) arranged on the left and right.

It is configured to form a pincushion-shaped magnetic field that is larger than the surface magnetic flux density of (50b) and stronger than the magnetic field strength formed by the permanent magnets (50a) and (50b) arranged on the left and right sides. These permanent magnets (28a)
.

The configuration and arrangement of (28b), (50a), and (50b) correspond to the arrangement of the permanent magnets in the second embodiment.

In this way, the permanent magnet (28a) is attached to the electron gun structure (20).
.

(28b) or permanent magnet (28a), (28b
), (50a).

Even if (50b) is arranged, it is possible to obtain a color picture tube that exhibits the same effects as those of the corresponding embodiments 1 and 2.

In the third embodiment, a pair of permanent magnets are arranged inside the convergence cup at the top and bottom or at the top, bottom, left and right, but these permanent magnets can also be arranged, for example, in a grid that constitutes the main lens part of the electron gun structure. . 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-mentioned embodiments flr, 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.

[Effects of the Invention] The electron gun assembly 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 on the electron gun assembly side. When a pair of permanent magnets is placed above and below or on the left and right of the top and bottom to form a pincushion-shaped magnetic field near the electrode located on the phosphor side with respect to the main lens part, the pincushion-shaped magnetic field formed by these permanent magnets causes the deflection device to It is possible to correct the deflection aberration that the magnetic field exerts on the electron beam, and to improve the focusing characteristics in the periphery of the screen.

[Brief explanation of the drawing]

1 to 15 are detailed explanatory diagrams of this invention.
The figure shows the configuration of a self-convergence type in-line color picture tube, which is the first embodiment of the invention. FIG. 3 is a perspective view showing the shape of the permanent magnet, and FIGS. 5 is a diagram showing the configuration of the electron lens section of the electron gun assembly, FIG. 6 is a diagram for explaining the effect that the pincushion-shaped magnetic field formed by the pair of upper and lower permanent magnets has on the spot of the electron beam, and FIG. The figure is also a diagram for explaining the static concentration effect of the pincushion-shaped magnetic field formed by the pair of upper and lower permanent magnets, and Figures 8 and 9 are for comparison with the static concentration effect of the pair of upper and lower permanent magnets, respectively. Figure 10 shows the configuration of the electron lens section for static concentration of the conventional electron gun assembly shown in Figure 10, and Figure 10 explains the non-rotationally symmetrical lens function of the pincushion-shaped magnetic field formed by the pair of upper and lower permanent magnets. FIG. 11 is a perspective view showing the arrangement of pairs of permanent magnets on the upper, lower, left, and right sides of the electron gun assembly side end of the deflection device, which is a main component of the second embodiment, and FIG. 12 is a perspective view showing the pair of left and right permanent magnets. 13 is a diagram for explaining the pincushion-shaped magnetic field formed by the permanent magnets in the upper, lower, left, and right pairs. Figure 14 (a) and ( b) is a cross-sectional view showing the configuration of an electron gun assembly in which upper and lower pairs of permanent magnets are arranged, which are the main components of the third embodiment, and a diagram showing the arrangement of upper and lower pairs of permanent magnets and a magnetic field control element, respectively. , Figure 15 (a
) and (b) are sectional views showing the structure of an electron gun assembly in which pairs of permanent magnets are arranged on the upper, lower, left and right sides, respectively, and views showing the arrangement of the pairs of permanent magnets on the upper, lower, left and right sides and magnetic field control elements,
Fig. 16 is a block diagram of a conventional self-convergence type in-line color picture tube, Fig. 17 is a perspective view showing the structure of a deflection device attached to the color picture tube, and Fig. 18 shows deflection by the uniform magnetic field of the deflection device. Figure 19 is an explanatory diagram of the spot shape of the electron beam deflected by the nonuniform magnetic field of the deflection device, and Figures 20 (a) and (b) are the pinpoints for the electron beam, respectively. FIG. 3 is a diagram for explaining the effects of a cushion-shaped horizontal deflection magnetic field and a barrel-shaped vertical deflection magnetic field. 5... Fluorescent screen 20... Electron gun structure 21.
...Deflection device 23...Horizontal deflection coil 24.
...Core 25...Vertical deflection coil 27.
...Electron gun structure side ends 28a, 28b of the deflection device...
・Pair of upper and lower permanent magnets 31...first grid 32
...Second grid 38...Third grid 34.
...4th grid 35...5th grid 35...
・Sixth grid 37...Convergence cups 39a, 39b...Center beam passage holes 40a-4
Qd... Side beam passage holes 41a, 41b -...
Magnetic body 42... Barrel-shaped vertical deflection magnetic field 43... Pincushion-shaped magnetic field 50a, 5Qb formed by a pair of upper and lower permanent magnets... 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 fields B and R formed between adjacent permanent magnets
...Pair of side beams G...Center beam Agent Patent attorney Norihiro Ogo Figure 6 Figure 8 Figure 10 Figure 11 Figure 12 Figure 13 Figure 15

Claims (7)

[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 deflection device including a second deflection coil that forms a deflection magnetic field; and a deflection device that connects 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. The strength and position of each generated magnetic field are determined so as to generate a pincushion-shaped magnetic field that compensates for the deflection aberration due to the deflection magnetic field formed by the second deflection coil on the path and statically concentrates the three electron beams. and a plurality of permanent magnets set mutually. (2) 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 deflection device including a second deflection coil that forms a deflection magnetic field; and a deflection device that connects 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 are disposed on the path, axially symmetrical with respect to the central axis of the deflection device, with 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, and the and a plurality of permanent magnets in which the strength and arrangement position of each generated magnetic field are mutually set so as to generate a pincushion-shaped magnetic field that compensates for the deflection aberration due to the deflection magnetic field formed by the second deflection coil. A color picture tube featuring (3) Claim 1, further comprising a coma aberration correction means made of a magnetic material that couples with the rear leakage demagnetizing field of the deflection device.
or the color picture tube described in 2. (4) The distance between the magnetic poles of each of the pair of permanent magnets arranged in a direction perpendicular to the direction in which the three electron beams are arranged is smaller than the distance in the direction in which the pair of side beams are arranged. color picture tube. (5) 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; The second beam is placed on the path of the three electron beams on the electron gun structure side in response to the deflection magnetic field formed by the coil.
The strength and arrangement position of each generated magnetic field were mutually set so as to generate a pincushion-shaped magnetic field that compensates for deflection aberration due to the deflection magnetic field formed by the deflection coil and statically focuses the three electron beams. A deflection device characterized by having a plurality of permanent magnets. (6) 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; A pair of coils are arranged on the path of the three electron beams on the electron gun structure side 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, corresponding to the deflection magnetic field formed by the coil. , a plurality of permanent magnets whose respective magnetic field strengths and placement positions 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 deflection device comprising: (7) According to claim 4 or 5, the distance between the magnetic poles of each of the pair of permanent magnets arranged in a direction perpendicular to the direction in which the three electron beams are arranged is smaller than the distance in the direction in which the pair of side beams are arranged. deflection device.