JPH11144645A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube that has high operability and excellent adjustment efficiency. SOLUTION: In order to shield an external magnetic field on three electron beams linearly arranged in the X-axis direction, a pair of band-like first magnetic bodies 33a, 33b stretched in the Z-axis direction are arranged opposite to each other on the X-axis. In the vicinity of the Y-axis at a predetermined distance away from a ring-like six-pole magnet plate 30, a pair of arc-like second magnetic bodies 60a, 60b placed symmetrically with respect to the X-Z plane are arranged. By placing the first magnetic bodies, the second magnetic bodies and the six pole magnet plate in such a positional relationship, a predetermined magnetic field distribution is formed. A cathode 46 of an electron gun structure is placed at the position where the sum total of positive magnetic field components equals that of negative magnetic field components on the track of the center beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube, and more particularly to a color picture tube provided with an in-line type electron gun assembly and having improved convergence characteristics of a plurality of electron beams emitted from the in-line type electron gun assembly. About pipes.

[0002]

2. Description of the Related Art Generally, an in-line type color picture tube is
As shown in FIG. 1, there is provided an envelope composed of a panel 1 and a funnel 2 connected to the panel 1. Panel 1
Is provided with a phosphor surface 3 composed of a three-color phosphor layer that emits red (R), green (G), and blue (B) light, respectively. Further, a shadow mask 4 is arranged so as to be closely opposed to the phosphor surface 3.

Further, this color picture tube has a funnel 2
As shown in FIG. 2, a horizontal axis or X
An in-line type electron gun structure that emits three electron beams arranged in a line on the axis is provided. That is, the electron gun assembly includes a center beam emitted toward the green phosphor layer on the phosphor surface 3 and a pair of side beams emitted toward the red phosphor layer and the green phosphor layer on the phosphor surface 3. Release.

Further, as shown in FIG. 1, the color picture tube has a deflecting device 6 mounted on the outer periphery of the funnel 2 to the neck 5. At the rear end of the deflecting device 6, a two-pole magnet 7 having a pair of N and S poles arranged to face each other is arranged.
This two-pole magnet 7 is used to adjust the landing of the electron beam.

[0005] A convergence magnet 8 is arranged outside the neck 5. The convergence magnet 8 includes at least a ring-shaped four-pole magnet plate 11 and a ring-shaped six-pole magnet plate 1.
0. The four-pole magnet plate 11 has two sets of N poles and S poles arranged to face each other. The six-pole magnet plate 10 has three sets of N poles and S poles arranged to face each other.

As described above, the two-pole magnet 7 and the convergence magnet 8 align the three electron beams emitted from the electron gun assembly at the center of the fluorescent screen 3 when there is no deflection,
Adjustments are made to achieve sufficient color purity and convergence.

The color picture tube deflects the three electron beams emitted from the electron gun assembly by the non-uniform magnetic field formed by the deflecting device 6 and scans the phosphor surface to scan the electron beam.
A color image is reproduced on the phosphor screen 3.

In such an in-line type color picture tube, the electron beam is easily affected by an external magnetic field such as terrestrial magnetism. In addition, when the convergence adjustment is performed in a different direction from the convergence adjustment, or when the convergence adjustment is performed in an area different from the geomagnetic condition of the adjustment place, the condition of the external magnetic field is different. For this reason, a problem may occur in which the red image and the blue image displayed on the phosphor surface by the pair of side beams are relatively displaced in the vertical direction. The principle of occurrence of such a phenomenon is considered as follows.

According to Japanese Patent Application Laid-Open No. 7-250335,
The electron gun assembly is disposed in the neck as described above. This electron gun assembly has a cathode that generates thermal electrons when heated by a heater. This cathode is formed of a low thermal expansion material, that is, a magnetic material. For this reason, for example, in the use environment,
When an external static magnetic field such as terrestrial magnetism interlinks in the tube axis of the neck, that is, in the Z-axis direction, the external magnetic field is converged toward the cathode which is a magnetic material. This allows
A magnetic field acts on the pair of side beams, in particular, of the three electron beams in opposite directions in the horizontal direction. These opposing magnetic fields exert opposing forces on the respective side beams.

That is, the external magnetic field has horizontal components, ie, X-axis components, which are opposite to each other for each side beam. For example, when an external magnetic field in the positive direction of the X-axis acts on the electron beam for red, a force acts in a downward direction in the vertical direction, that is, a negative direction in the Y-axis direction. Shifts in the negative direction. On the other hand, since an external magnetic field in the negative X-axis direction acts on the blue electron beam, a force acts in the positive Y-axis direction, and the blue electron beam moves in the positive Y-axis direction. shift. This causes a problem that the red image and the blue image displayed on the phosphor surface by the pair of side beams are relatively shifted up and down.

According to Japanese Patent Application Laid-Open No. Hei 7-21938, when trying to converge three electron beams, a pair of side beams has magnetic field components that are opposite to each other in the X-axis direction. When an external magnetic field in the Z-axis direction is applied in this state, there is a concept that an image displayed by the side beam is relatively shifted up and down due to the Lorentz force as described above.

As shown in FIG. 2, a pair of magnetic members 9 for shielding an external magnetic field in the Z-axis direction are arranged to prevent the image displayed by the side beam from being displaced. The magnetic body 9 extends along the Z-axis direction,
It is arranged on both outer sides of the neck 5 located on the axis.

As shown in FIG. 2, the magnetic body 9 is usually provided on the inner surface of the cylindrical holder H of the convergence magnet 8 along the Z-axis direction in order to reduce the number of mounting steps and control the mounting accuracy. Fixed.

On the other hand, as shown in FIG. 3, the six-pole magnet plate 10 has three N poles and three S poles at equal intervals on a ring-shaped magnet plate. These poles are alternately arranged to form a magnetic field distribution as shown in FIG. This magnetic field distribution changes the trajectory of the side beams by applying a force in the same direction to the pair of side beams depending on the shape. On the other hand, on the trajectory of the center beam, that is, on the center axis of the color picture tube, the magnetic field intensity is canceled out to be almost zero, and the design is made so that a force that changes the trajectory does not act.

[0015]

As described above, the convergence magnet for forming the static magnetic field for correcting the trajectory of the three electron beams and the magnetic material for shielding the external magnetic field are limited in the neck portion. When arranged within the dimensions, as shown in FIG. 2, a part of the band-shaped magnetic body and a part of the ring-shaped magnet plate intersect.

As described above, when the magnetic body and the magnet plate are arranged close to each other, the magnetic body is magnetized by the action of the magnetic poles of the magnet plate, particularly the six-pole magnet plate. This causes the following problem.

FIGS. 4A and 4B show the distribution of the magnetic field formed by the six-pole magnet plate when correcting the trajectories of both side beams of the three electron beams in the positive direction in the Y-axis direction. , And how the magnetic material is magnetized.

In this case, the six-pole magnet plate 10
Are arranged such that one N pole and one S pole face each other on the X axis. At this time, a part of the magnetic bodies 9a and 9b opposed to each other on the X axis is arranged close to the N pole and the S pole of the six-pole magnet plate 10, respectively. Therefore, the portions of the magnetic bodies 9a and 9b adjacent to the poles of the six-pole magnet plate 10 are magnetized to have the opposite polarity to the adjacent magnetic poles. The entire magnetic body is magnetized along the length direction, that is, the Z-axis direction. As a result, the front end of the magnetic body, that is, the end near the magnet plate, and the rear end of the magnetic body have a dipole magnetic field. Occurs.

That is, the magnetic body 9 located on the + side of the X axis
An S pole is generated on the surface of the magnetic plate 9a in contact with the N pole, and an N pole is generated at the front end and the rear end of the magnetic body 9a. Similarly, an N pole is generated on the surface of the magnetic body 9b located on the negative side of the X axis and in contact with the S pole of the magnet plate 10,
An S pole is generated at the front end and the rear end of the magnetic body 9b.

Thus, at the rear end of the magnetic bodies 9a and 9b, a magnetic field from the magnetic body 9a to the magnetic body 9b, that is, a negative magnetic field component from the + side to the-side along the X-axis direction is formed. Due to such a magnetic field component, an upward force acts on the electron beam passing near the rear end of the magnetic body.

In the vicinity of the surface of the six-pole magnet plate 10, the magnetic flux of the pole located on the X axis is changed by the magnetic members 9a, 9b.
, The negative magnetic field component formed by the magnet plate 10 from the + side to the − side on the X axis weakens.
As described above, the magnet plate 10 is arranged so that the magnetic field strength becomes zero on the center beam trajectory by the balance of the magnetic field between the two poles on the X axis and the four poles near the Y axis in a state where the magnetic body is not disposed. Designed. However, when a magnetic body is disposed, the magnetic field due to the two poles on the X axis is induced by the magnetic body and weakened, and the magnet plate 10 has + poles from the minus side in the X axis direction where four poles near the Y axis are generated. The positive magnetic field component toward the side becomes relatively strong.

That is, in the vicinity of the front end of the magnetic material, a negative magnetic field component is generated from the + side to the − side on the X axis, as in the vicinity of the rear end. Since the positive magnetic field component from the − side to the + side in the axial direction is relatively strong, a positive magnetic field component is generated by the sum of the magnetic fields on the center beam trajectory.

That is, a negative magnetic field component is generated on the trajectory of the side beam near the magnet plate 10, and a positive magnetic field component is generated on the trajectory of the center beam. And the directions of the magnetic fields on the orbit are opposite to each other.

As described above, in each trajectory of the three electron beams, the magnetic field received by each electron beam emitted from the cathode 16 before reaching the deflecting device 6 is general with respect to the trajectory of the center beam. A positive magnetic field acts on the trajectory of the side beam, and a negative magnetic field acts on the trajectory of the side beam as a whole. Therefore, the side beam passing through the surface of the six-pole magnet plate receives a force in the positive direction of the Y-axis, and the center beam receives a force in the reverse direction of the negative direction of the Y-axis.

As a result, when the trajectory of the electron beam is adjusted, the movement of the center beam is zero with no magnetic material,
When a magnetic material is attached to a magnet plate that can move both side beams by 1.3 mm in the Y axis direction + side, both side beams move by 0.5 mm in the Y axis direction + side, and the center beam moves in the Y axis direction-side. Move 0.8 mm.

This not only deteriorates the operability of the magnet plate, but also causes the center beam to move when the beam trajectory is corrected by the six-pole magnet plate after the landing adjustment by the two-pole magnet plate. As a result, it becomes necessary to adjust the landing, and the efficiency of the adjustment operation is reduced.

As described above, in correcting the trajectory of the electron beam in the vertical direction when the magnetic body is mounted, the amount of movement of both side beams decreases, and the center beam moves in the direction opposite to the side beam. Occurs.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a color picture tube having excellent operability and excellent adjustment efficiency.

[0029]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the object, the present invention provides an outer enclosure comprising a panel having a phosphor surface formed on an inner surface thereof and a neck connected to the panel via a funnel. A vessel, provided in the neck,
An electron gun assembly including a cathode that emits three electron beams arranged on a horizontal axis in a tube axis direction toward the panel side, and mounted on the outside of the neck, on an orbit of the electron beam emitted from the cathode. A multi-pole magnetic field generating means having at least a multi-pole magnetic plate for generating a multi-pole magnetic field, and the horizontal axis being the X axis, the tube axis being the Z axis, and the vertical axis being orthogonal to the horizontal axis and the tube axis. A pair of band-shaped first magnetic bodies attached to each other with the electron gun structure interposed therebetween so as to be symmetric with respect to the YZ plane when defined as the Y axis, and extending in the tube axis direction; X- in the XY plane
A second magnetic body symmetrically arranged with respect to the Z plane; and three electrons emitted from the cathode by the pair of the first magnetic body, the second magnetic body, and the multipole magnet plate. A positive magnetic field component from the one first magnetic body toward the other first magnetic body along the Z-axis direction on the trajectory of the center beam of the beams;
Forming a magnetic field distribution having a negative magnetic field component from the other first magnetic body toward the one first magnetic body, wherein the cathode is located on a trajectory of the center beam at a position along the Z-axis direction. It is an object of the present invention to provide a color picture tube characterized by being arranged at a position where the sum of the positive magnetic field components and the sum of the negative magnetic field components are substantially equal.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color picture tube according to the present invention, in particular, an embodiment of an in-line color picture tube having an in-line type electron gun assembly will be described in detail with reference to the drawings. The in-line type color picture tube according to this embodiment has a panel 21 as shown in FIGS.
A funnel 22 connected to the panel 21 and a neck 25 as a small-diameter end connected to the funnel 22.
And an envelope consisting of: The panel 21 has on its inner surface a phosphor surface 23 having three-color phosphor dots that emit red (R), green (G), and blue (B), respectively. Further, the color picture tube includes a shadow mask 24 having a large number of electron beam passage holes at a position close to and opposed to the phosphor surface 23.

As shown in FIG. 6, this color picture tube has an in-line type electron gun structure 40 for emitting three electron beams arranged in a line on a horizontal axis, that is, an X axis, inside a neck 25. It has. The in-line type electron gun assembly 40 has a center beam 41G emitted toward the green phosphor dots on the phosphor surface 23, and a pair of red beams and green phosphor dots emitted toward the red and green phosphor dots on the phosphor surface 23, respectively. The side beams 41R and 41B are emitted. This type electron gun assembly 40 has three cathodes 46 arranged in a line in which heaters are provided, and a plurality of electrodes sequentially arranged in the tube axis direction, that is, the Z axis direction from the cathodes 46 toward the phosphor surface 23. . Each of the plurality of electrodes functions to control, focus, and accelerate each electron beam emitted from each cathode. Both the cathode 46 and the plurality of electrodes are integrally fixed by an insulating support. A stem pin 34 for supplying a predetermined voltage to the in-line type electron gun structure 40 is attached to the rear end of the neck 25.

Further, the color picture tube is mounted on the outer periphery of the funnel 22 from the funnel 22 to the neck 25.
A deflection device 36 for forming a non-uniform magnetic field is provided. This deflecting device 36 has a pair of saddle-type horizontal deflection coils and a pair of saddle-type vertical deflection coils. The horizontal deflection coil forms a pincushion-type deflection magnetic field, and the vertical deflection coil forms a barrel-type deflection magnetic field.

The color picture tube is provided with a deflecting device 36.
A ring-shaped two-pole magnet 37 and a convergence magnet 32 are provided outside the neck 25 located on the rear end side of the rim.

The two-pole magnet 37 has a pair of N pole and S pole arranged to face each other.
The magnetic field formed by the two-pole magnet 37 adjusts the axial deviation of the electron beam, that is, the deviation of the incident angle of the electron beam with respect to the shadow mask, and corresponds to the phosphor dots of each color formed on the phosphor screen. The electron beam to be projected. That is, the two-pole magnet 37 is used for such landing adjustment. In this landing adjustment, the side beam 41R is set to the red phosphor dot on the phosphor surface 23, the center beam 41G is set to the green phosphor dot on the phosphor surface 23, and the side beam 41B is set to the
It is adjusted so as to project on the blue phosphor dots on the phosphor surface 23, respectively.

The convergence magnet 32 includes at least two ring-shaped four-pole magnet plates 31.
And two ring-shaped six-pole magnet plates 32. The four-pole magnet plate 31 has two pairs of N poles and S poles arranged to face each other.
Generates a pole static magnetic field. 6-pole magnet plate 31
Are three sets of north poles and S
It has poles and generates a 6-pole static magnetic field.

The static magnetic field formed by the 4-pole magnet plate 31 and the 6-pole magnet plate 30 controls the center beam 41G by operating the side beams, particularly both side beams, of the three electron beams arranged in a row in the horizontal and vertical directions. The three electron beams are aligned so that the side beams 41R and 41B are evenly arranged on both outer sides.

As described above, the two-pole magnet 37 and the convergence magnet 32 align the three electron beams arranged in a line in the center of the phosphor surface 3 when the electron gun assembly 40 is not deflected, and provide sufficient color purity and sufficient color purity. Adjusted to achieve convergence.

The three electron beams are supplied to the deflection device 3
6 deflects in the horizontal direction, that is, the X-axis direction and the vertical direction, that is, the Y-axis direction that is orthogonal to the horizontal direction, to converge while scanning on the phosphor surface 23 to form a color image on the phosphor surface 23. I have.

In such an in-line type color picture tube, in order to shield an external magnetic field such as terrestrial magnetism which adversely affects the electron beam emitted from the electron gun structure, in particular, an external magnetic field along the Z-axis direction, As shown in FIG. 7A, a pair of band-shaped first magnetic bodies 33a and 33b extending along the Z-axis direction are arranged on both outer sides of the neck 25. The pair of first magnetic bodies 33a and 33b are arranged to face each other on the X axis.

That is, the convergence magnet 3
2 has a ring-shaped six-pole magnet plate 30 and a four-pole magnet plate 31 that generate at least a static magnetic field, and is attached to a cylindrical holder 50 for attaching these ring-shaped magnet plates to the neck 25. I'm hanging.

As described above, each of the six-pole magnet plate 30 and the four-pole magnet plate 31 is composed of two plates. Two 4-pole magnet plates,
By adjusting the rotation angle of each magnet plate in the XY plane orthogonal to the Z axis, the intensity of the magnetic field generated by the quadrupole magnet plate can be adjusted. That is, when the handle portions of the two magnet plates are combined, the S and N poles of one magnet plate are arranged so as to face the N and S poles of the other magnet plate, respectively. Thereby, the magnetic fields of the respective magnet plates cancel each other, and the magnetic field intensity generated by the magnet plates is minimized. On the other hand, when one magnet plate is rotated by 90 degrees with respect to the other magnet plate, the S and N poles of one magnet plate are arranged so as to face the S and N poles of the other magnet plate, respectively. . This maximizes the magnetic field intensity generated by the magnet plate.

Similarly, the six-pole magnet plate 30
Take the two magnet plates and put them together,
When the magnetic field strength is minimized and one magnet plate is rotated 60 degrees with respect to the other magnet plate,
The magnetic field strength is maximized.

In the convergence magnet 32, the cylindrical holder 50 has six stems from the stem pin 34 side.
Pole magnet plate 30, 4-pole magnet plate 3
1, and a fixing ring are arranged in order. A 6-pole magnet plate 30 and a 4-pole magnet plate 31
A first division spacer is disposed between the two to mechanically separate the two magnet plates. Also, 4
A second division spacer is arranged between the pole magnet plate 31 and the fixing ring.

The convergence magnet 32 having such a structure is fixed to the neck 25 by a fastening band 51 and a fastening screw 52 attached to the end of the holder 50.

The pair of first magnetic bodies 33a and 33b are fixed at positions on the X axis on the inner surface of the cylindrical holder 50 so as to face each other. That is, the pair of first magnetic bodies 33a and 33b are fixed to the holder 50 so as to be in contact with the outer wall of the neck 25.

In this embodiment, a pair of first magnetic members 3
Each of 3a and 33b is formed using a cold-rolled silicon steel sheet, and has an example of dimensions of a thickness of 0.35 mm, a length of 35 mm, and a width of 4 mm.

As shown in FIG. 7A, the second magnetic bodies 60a, 60b are located 1.5 mm away from the center of the six-pole magnet plate 30 along the Z-axis toward the deflecting device.
Is arranged. The second magnetic bodies 60a and 60b
The holder 50 is provided symmetrically with respect to the XZ plane in the XY plane. That is, the second magnetic bodies 60a and 60b are formed by a pair of magnetic bodies 60a and 60b which are cut in the vicinity of the X-axis and are opposed to each other over a range of 50 degrees near the Y-axis. This second
The magnetic bodies 60a, 60b are
A plate-like member shaped into an arc shape so as to have substantially the same curvature as the inner shape of, for example, a width of 1.0 mm and a thickness of 0.2
mm of a cold-rolled silicon steel sheet.

As shown in FIG. 7B, a pair of cylindrical second magnetic members 61a are provided at a position 1.5 mm away from the center of the six-pole magnet plate 30 along the Z-axis toward the deflecting device. , 61b may be arranged. The pair of second magnetic bodies 61a and 61b are cylindrical members shaped to have substantially the same curvature as the inner shape of the six-pole magnet plate 30, for example, a cold member having a width of 1.0 mm and a plate thickness of 0.2 mm. It is formed by cold rolled silicon steel sheet.

The pair of second magnetic bodies 61a and 61b are
It is provided on the inner surface of the holder 50 so as to be symmetric with respect to the XZ plane in the XY plane. That is,
The pair of second magnetic bodies 61a and 61b are cut in the vicinity of the X-axis and are opposed to each other in the vicinity of the Y-axis over a range of 50 degrees.

Even when a pair of cylindrical second magnetic bodies 61a and 61b as shown in FIG.
A pair of arc-shaped second magnetic bodies 6 as shown in FIG.
The same effect as in the case where 0a and 60b are applied can be obtained.
Here, the effect of the case where the second magnetic body having the shape shown in FIG. 7A is applied will be described.

FIG. 8 shows the positional relationship between the six-pole magnet plate and the first and second magnetic bodies when the trajectory of the electron beam is corrected in the upward direction of the vertical axis, that is, in the + direction of the Y-axis direction. ing.

In this case, the six-pole magnet plate 30
Is a 6-pole magnet plate 3 on the horizontal axis, that is, the X axis.
The N pole and the S pole of 0 are arranged so as to face each other. At this time, the front ends of the pair of first magnetic bodies 33a and 33b, which are opposed to each other on the X axis, that is, the ends on the Z-axis side are close to the N pole and the S pole of the six-pole magnet plate 30, respectively. doing. Therefore, the surfaces of the first magnetic bodies 33 a and 33 b adjacent to the poles of the six-pole magnet plate 30 are magnetized to have the opposite polarity to the magnetic poles of the six-pole magnet plate 30. The entire first magnetic body is magnetized along the length direction, that is, the Z-axis direction. As a result, the front end of the first magnetic body, that is, Z
A bipolar magnetic field is generated at the end on the negative side of the axis and at the rear end of the magnetic material, that is, on the positive end of the Z axis.

That is, the magnetic body 33 located on the X axis + side
a, an S pole is generated on the surface in contact with the N pole of the six-pole magnet plate 30, and N poles are formed at the front end and the rear end of the magnetic body 33a.
Poles occur. Similarly, the magnetic body 33 located on the negative side of the X axis
b, an N pole is generated on the surface in contact with the S pole of the six-pole magnet plate 30, and S poles are formed at the front end and the rear end of the magnetic body 33b.
Poles occur.

Thus, the pair of first magnetic bodies 33a, 3a
At the rear end of 3b, a magnetic field from the magnetic body 33a to the magnetic body 33b, that is, a magnetic field from the + side to the-side along the X-axis direction, that is, a negative magnetic field is formed. A pair of first magnetic bodies 3
Since the rear ends of the magnets 3a and 33b are located on the stem pin side of the cathode 46 of the electron gun structure, the magnetic members 33a and 33b
Does not act on the electron beam emitted from the cathode 46.

At the intermediate portion between the pair of first magnetic bodies 33a and 33b, a negative magnetic field is formed similarly to the rear end portion, since they are magnetized to the N pole and the S pole, respectively. Due to such a magnetic field, an electron beam passing through an intermediate portion between the pair of first magnetic bodies 33a and 33b receives an upward force.

In the vicinity of the surface of the six-pole magnet plate 30 and at the front ends of the pair of first magnetic bodies 33a and 33b,
The magnetic flux of the pole located on the X axis is the first magnetic body 33a, 33b
, The negative magnetic field formed by the six-pole magnet plate 30 on the electron beam trajectory from the + side to the − side on the X axis is weakened.

Further, the pair of second magnetic bodies 60a and 60b arranged on the deflection device side along the Z-axis direction from the center of the six-pole magnet plate 30 generate four poles near the Y-axis of the six-pole magnet plate. The magnetic field from the negative side to the positive side in the X-axis direction, that is, the positive magnetic field is bypassed. As a result, of the magnetic fields generated by the four poles near the Y-axis, the positive magnetic field from the − side to the + side in the Y-axis direction that interlinks on the center beam trajectory decreases.

That is, the pair of first magnetic bodies 33a, 33
b, and a pair of second magnetic bodies 60a, 60b
The negative magnetic field generated by two poles on the X axis of the pole magnet plate 30 is weakened, and the positive magnetic field generated by four poles near the Y axis is weakened. Therefore, the center beam of the magnetic field generated by the six poles of the six-pole magnet plate 30 is:
On its orbit, it is affected by a relatively small positive magnetic field. The positive magnetic field acting on the trajectory of the center beam is smaller than before, and can be made substantially zero.

On the other hand, the side beam is applied to the first magnetic body 33.
On its trajectory at the front end of a, 33b, it is affected by a negative magnetic field. Therefore, the first magnetic body 33a,
At the front end of the beam 33b, a positive magnetic field acts on the center beam to receive a downward force, that is, a force toward the minus side in the Y-axis direction. That is, the force is applied to the positive side in the Y-axis direction.

FIG. 9 shows a horizontal magnetic field intensity distribution curve on each orbit of three electron beams arranged in a line in a conventional color picture tube. FIG. 10 shows a horizontal magnetic field intensity distribution curve on each orbit of three electron beams arranged in a line in the color picture tube according to the present embodiment.

The horizontal axes of the graphs shown in FIG. 9 and FIG.
The position in the tube axis direction, that is, the Z-axis direction is shown. 0 is the center position of the six-pole magnet plate, negative is on the deflection device side, and positive is on the stem pin side. The vertical axis indicates the relative value of the magnetic field intensity on each orbit of the center beam and the side beam of the three electron beams, and the sign indicates the direction of the magnetic field. Positive indicates a magnetic field directed in the + direction on the X axis, and negative indicates a magnetic field directed in the negative direction on the X axis. The solid line in the figure shows the distribution of the magnetic field strength on the trajectory of the center beam, and the broken line in the figure shows the distribution of the magnetic field strength on the trajectory of the side beam.

In FIGS. 9 and 10, the difference between the sum of the positive magnetic field components and the sum of the negative magnetic field components along the tube axis direction from the cathode position toward the deflection device is determined by the magnetic field acting on each electron beam. Equivalent to strength. The moving amount of the electron beam in the Y-axis direction is determined by the magnetic field strength. That is, if the difference between the magnetic field components is positive, as shown in FIG. 8, the electron beam causes a downward force toward the − side in the Y axis direction due to the magnetic field component going from the − side to the + side on the X axis. Receive. If the difference between the magnetic field components is negative, the electron beam receives an upward force toward the + side in the Y-axis direction due to the magnetic field component going from the + side to the − side on the X axis.

The example shown in FIG. 9 is an example in which only a pair of first magnetic bodies 9a and 9b are arranged on a convergence magnet in a positional relationship as shown in FIG. The front end is arranged close to the six-pole magnet. The first magnetic body is arranged such that its front end is located at a position of -5 mm and its rear end is located at a position of +30 mm. The position of the cathode is a position of +6 mm.

In this case, in the region on the stem pin side where the first magnetic body is provided, a negative magnetic field is generated on each of the orbits of the center beam and the side beam. A strong positive magnetic field is generated on the beam trajectory.

The cathode is arranged at a position of +6 mm. On the deflecting device side from the cathode position, a strong positive magnetic field component acts on the trajectory of the center beam as shown in FIG. Therefore, a force acts on the center beam in a downward direction, that is, a negative direction in the Y-axis direction.

When the trajectory of the side beam is changed, it is desirable that the amount of movement of the center beam be zero, and therefore, it is desirable that the difference between the magnetic field components in the trajectory of the center beam be zero. That is, in this example, in order to reduce the amount of movement of the center beam, it is necessary to reduce the positive magnetic field strength.

At the time of adjusting the electron beam trajectory by the six-pole magnet plate, the side beam is moved upward by 1.3 with the center beam moving amount being 0 and the magnetic body being not disposed.
By mounting a magnetic body as shown in the example shown in FIG. 9 on a magnet plate that can be moved mm, the center beam moves 0.8 mm downward and the side beam moves 0.5 mm upward.

In the example shown in FIG. 10, as shown in FIG. 8, a pair of first magnetic bodies 33a and 33b and a pair of second magnetic bodies 33a and 33b are used.
This is an example of a convergence magnet including magnetic bodies 60a and 60b. The first magnetic body has a front end of −5 mm.
And the rear end is located at a position of +30 mm.

The cathode is located at a position of +9 mm. The position of the cathode is near the point where the magnetic field component reverses from positive to negative on the trajectory of the center beam, and is closer to the stem pin than the point where the polarity of the magnetic field component reverses. Since the electron beam emitted from the cathode travels toward the deflection device side, that is, toward the minus side in the tube axis direction, the magnetic field on the stem pin side from the cathode position does not act on the electron beam. For this reason, it is possible to limit a negative magnetic field component that is stronger on the stem pin side than the cathode from acting on the electron beam.

The distribution of the magnetic field intensity on the deflecting device side from the cathode position on the trajectory of the center beam is such that a negative magnetic field component is generated from the cathode position of +9 mm to the position of about +3 mm along the tube axis direction. The polarity of the magnetic field is reversed at a position of about +3 mm. Then, a positive magnetic field component is generated from the position of +3 mm to the range on the deflection device side.

When the magnetic field intensity distribution on the orbit of the center beam shown in FIG. 10 is compared with that shown in FIG.
In the vicinity of the six-pole magnet, the positive magnetic field component is reduced by the action of the second magnetic body. In addition, since the position of the cathode with respect to the six-pole magnet plate is located closer to the stem pin than in the related art, the negative magnetic field component increases.

Accordingly, the magnetic field in the X-axis direction acting on the center beam of the electron beams emitted from the cathode toward the deflection device has an integral value of a positive magnetic field component and an integral value of a negative magnetic field component substantially equal to each other. Equal and offset each other.

Assuming that the sum of the absolute value of the integral value of the positive magnetic field component and the integral value of the negative magnetic field component in the magnetic field strength distribution is 100%, the integral value of the positive magnetic field component in the example shown in FIG. Is 10
At 0%, the integral value of the negative magnetic field component is 0%, and only the positive magnetic field component exists. On the other hand, in the example shown in FIG. 10, the integral value of the positive magnetic field component is 45% and the integral value of the negative magnetic field component is 55%, and the integral values of the magnetic field strength for each component are almost equal. Has become.

Therefore, it is possible to minimize the difference between the sum of the positive magnetic field components acting on the center beam and the sum of the negative magnetic field components, thereby minimizing the force acting on the center beam. It becomes possible.

On the other hand, a negative magnetic field component acts on the side beam, and its integral value is larger than that of the conventional one shown in FIG. Therefore, it is possible to effectively move the side beam upward.

In this embodiment, the amount of movement of the electron beam is 1.3 mm for both side beams on the + side in the Y-axis direction and 0.2 mm for the center beam on the-side in the Y-axis direction. The variation in landing at this time is 1 μm, which is within the range of the allowable adjustment error. The amount of movement of the side beam is equivalent to the amount of movement in a state where no magnetic material is arranged when the trajectory of the electron beam is adjusted by the six-pole magnet plate.

This is because the magnetic field generated from the four poles near the Y-axis of the six-pole magnet plate is bypassed by the second magnetic body to the adjacent pole. Thus, the positive magnetic field component acting on the center beam orbit of the six-pole magnet plate and the negative magnetic field component are balanced. The adjustment of the magnetic field strength can be arbitrarily adjusted according to the plate thickness, magnetic permeability, width and the like of the second magnetic body.

In the color picture tube according to this embodiment, as shown in FIG.
Of a pair of arc-shaped second members shaped to have substantially the same curvature as the inner shape of the
The magnetic bodies 60a, 60b (61a, 61b) are arranged at positions near the Y axis with the X axis as the axis of symmetry.

That is, when the six-pole magnet plate 30 is formed in a ring shape having a circular inner shape, the second magnetic bodies 60a, 60b (61a, 61b) are centered on the intersection O between the X axis and the Y axis. It is formed in a flat plate shape (or a cylindrical shape) extending on an XY plane along the circumference. Then, the pair of second magnetic bodies 60a, 60b (61a, 6
1b) is arranged symmetrically about the Y axis over a range of a predetermined occupation angle A from the Y axis with respect to the intersection O. Second magnetic body 60a, 60b (61a, 61b)
Is proportional to the occupation angle A about the intersection O.

The second magnetic body is formed by arranging a pair of magnetic bodies cut in the vicinity of the intersection with the X axis to face each other, but may be formed in a series of rings. In the case of such a shape, it can be used as a spacer for mechanically separating a six-pole magnet plate and a four-pole magnet plate or a fixed ring, for example. Therefore, in assembling the convergence magnet, it is possible to assemble the convergence magnet more efficiently than in a structure in which a pair of magnetic bodies are arranged to face each other. In addition, the number of components can be reduced by also using the function as the spacer.

FIG. 12 shows the occupation angle A of the second magnetic material = 30.
FIG. 9 is a diagram showing a magnetic field intensity distribution curve on the orbit of the center beam when the plate thickness of the second magnetic body is changed in the case of °. Note that the second magnetic body is arranged at a position of -1.5 mm in the tube axis direction, as in the case shown in FIG. 7A.

In FIG. 12, the thickness of the second magnetic body is 0.1 m.
The magnetic field strength distribution for each of m, 0.2 mm, and 0.3 mm is shown. As shown in FIG. 12, it can be seen that, by increasing the thickness of the second magnetic body, a tendency is observed that the positive magnetic field component decreases and the negative magnetic field component increases. In particular, in the vicinity of the center of the six-pole magnet plate (position 0 in the tube axis direction), by increasing the thickness of the second magnetic body, it becomes possible to effectively reduce the positive magnetic field component.

As described above, by appropriately selecting the thickness of the second magnetic body, the center beam can be moved on the orbit of the center beam.
It is possible to adjust the balance between the positive magnetic field component and the negative magnetic field component.

FIG. 13 shows the shape of the second magnetic body in FIG.
FIG. 10 is a diagram showing a magnetic field intensity distribution curve on the trajectory of the center beam when the distance in the tube axis direction between the second magnetic body and the six-pole magnet plate is changed as in the case shown in FIG. The occupation angle A of the second magnetic body is 30 °,
The plate thickness and width are the same as those shown in FIG.

FIG. 13 shows a case where the second magnetic body is arranged at a predetermined distance from the center position of the six-pole magnet plate to the deflection device along the tube axis direction, and the interval is 0.8 mm (−). 0.8mm position), 1.0mm (-
The respective magnetic field strength distributions are shown for each of the cases of 1.0 mm (position of 1.0 mm) and 1.2 mm (position of -1.2 mm).

As shown in FIG. 13, by reducing the distance between the second magnetic body and the six-pole magnet plate,
It can be seen that there is a tendency that the positive magnetic field component decreases and the negative magnetic field component increases. In particular, near the center of the six-pole magnet plate, the distance between the second magnetic body and the six-pole magnet plate is reduced, so that the positive magnetic field component can be effectively reduced.

As described above, by properly selecting the distance between the third magnetic body and the six-pole magnet plate, the balance between the positive magnetic field component and the negative magnetic field component can be adjusted on the trajectory of the center beam. Is possible.

FIGS. 14 and 15 show the relationship between the occupation angle A of the second magnetic body and the integrated value of the magnetic field intensity acting on the center beam. In FIG. 14, the horizontal axis indicates the occupation angle A of the second magnetic body, and the vertical axis indicates the magnetic field intensity ratio acting on the center beam. The occupation angle of 0 ° on the horizontal axis indicates a case where the second magnetic body is not provided, and the occupation angle of 90 ° indicates a case where the second magnetic body is formed in a series of ring shapes.

The magnetic field strength ratio in FIG. 14 is the integral of the magnetic field strength acting on the center beam when the second magnetic body is not present (occupation angle = 0 °), that is, the absolute value of the positive magnetic field component and the negative magnetic field component. The ratio of the integral value of the magnetic field strength when the second magnetic body having a predetermined occupying angle is provided when the sum of the values is 100%.

As shown in FIG. 14, when the occupation angle of the second magnetic body is about 30 °, the magnetic field intensity ratio becomes minimum,
It can be seen that the sum of the magnetic field strengths generated on the center beam orbit is small regardless of the polarity.

FIG. 15 shows the ratio of the integral value of the positive magnetic field component to the integral value of the magnetic field intensity acting on the center beam and the ratio of the integral value of the negative magnetic field component separately. is there. In the state where the second magnetic body is not provided, most of the positive magnetic field component is provided. However, when the second magnetic body is disposed, the positive magnetic field component decreases as the occupied angle of the second magnetic body increases, and the negative magnetic field component decreases. The components tend to increase.

When the occupation angle A is about 25 ° to about 50
In the range of °, preferably about 30 ° or 45 °, the ratio between the integral value of the positive magnetic field component and the integral value of the negative magnetic field component becomes almost equal, and it can be seen that the ratio is optimal.

The occupation angle A exceeds this optimum range.
Increases, the positive magnetic field component begins to increase and the negative magnetic field component decreases. Thus, the occupation angle A of the second magnetic body
By appropriately selecting, it is possible to adjust the balance between the positive magnetic field component and the negative magnetic field component on the trajectory of the center beam.

As described above, the thickness of the second magnetic material,
By appropriately selecting the distance between the magnetic body and the six-pole magnet plate and the occupation angle A of the second magnetic body, the integrated value of the positive magnetic field component and the negative magnetic field component of the magnetic field strength acting on the center beam It is possible to adjust the balance with the integral value of. Thus, by disposing the cathode under conditions that cancel the positive magnetic field component and the negative magnetic field component, it is possible to suppress undesired movement of the center beam.

As described above, according to the color picture tube of the present invention, in addition to the pair of first magnetic bodies that are opposed to each other to shield the external magnetic field acting on the electron beam,
In the vicinity of the six-pole magnet plate, a pair of second magnetic bodies are arranged symmetrically with respect to the horizontal axis. The second magnetic body is shaped to have substantially the same curvature as the inner shape of the six-pole magnet plate.

Therefore, the magnetic field directed to the center beam generated from the pole near the vertical axis in the six-pole magnet is bypassed by the second magnetic body. Therefore, it is possible to suppress the magnetic field acting on the center beam without reducing the magnetic field acting on both side beams among the three electron beams arranged in a line. As a result, the center beam is hardly affected by the force that changes the trajectory, and the side beam is affected by the force that changes the trajectory in the vertical direction. Therefore, it is possible to change the trajectory of the side beam in the vertical direction without changing the trajectory of the center beam.

As a result, the operability of the convergence magnet is improved, and the center beam can be prevented from moving during correction by the six-pole magnet plate after the landing adjustment by the two-pole magnet.
There is no need to adjust the landing with the pole magnet plate, and an inline color picture tube with excellent adjustment efficiency can be provided.

[0098]

As described above, according to the present invention, it is possible to provide a color picture tube having good operability and excellent adjustment efficiency.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing the entire structure of a conventional in-line type color picture tube.

FIG. 2 is a perspective view schematically showing a convergence magnet of the conventional in-line type color picture tube shown in FIG.

FIG. 3 is a diagram showing a state of a magnetic field distribution formed by a six-pole magnet plate among convergence magnets.

FIG. 4A is a diagram showing the relationship between the arrangement positions of the convergence magnet and the magnetic body shown in FIG. 2, and FIG. 4B is a diagram showing the six poles shown in FIG. 4A; It is the figure which expanded the vicinity of the intersection of a magnet plate and a magnetic body.

FIG. 5 is a side view schematically showing the entire structure of the in-line type color picture tube of the present invention.

FIG. 6 is a partial cross-sectional view schematically showing a structure of an electron gun assembly provided in a neck of the in-line type color picture tube shown in FIG.

7A is a perspective view schematically showing a convergence magnet applied to the in-line type color picture tube shown in FIG. 5, and FIG. 7B is a perspective view showing the in-line type color picture tube shown in FIG. FIG. 10 is a perspective view schematically showing another convergence magnet applied to a mold color picture tube.

FIG. 8 is a diagram showing a relationship between arrangement positions of a six-pole magnet plate of the convergence magnet shown in FIG. 7A and first and second magnetic bodies.

FIG. 9 is a graph showing the horizontal magnetic field strength on the electron beam trajectory of the conventional in-line type color picture tube.

FIG. 10 is a graph showing the horizontal magnetic field strength on the electron beam trajectory of the in-line type color picture tube of the present invention.

FIG. 11 is a diagram for explaining an occupation angle A at which a second magnetic body is arranged.

FIG. 12 shows an occupation angle A of a second magnetic body of 30 °.
FIG. 10 is a diagram illustrating a magnetic field intensity distribution curve on the trajectory of the center beam when the plate thickness of the second magnetic body is changed in the case of FIG.

FIG. 13 shows a case where the shape of the second magnetic body is the same as that shown in FIG. 7 (A), and the distance between the second magnetic body and the six-pole magnet plate in the tube axis direction is changed. FIG. 4 is a diagram showing a magnetic field intensity distribution curve on the orbit of the center beam of FIG. .

FIG. 14 is a diagram showing a ratio of a magnetic field intensity acting on a center beam to an occupation angle A of a second magnetic body.

FIG. 15 is a graph showing a ratio of an integral value of a positive magnetic field component among integral values of a magnetic field strength and a ratio of an integral value of a negative magnetic field component to an occupation angle A of a second magnetic body. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Panel 22 ... Funnel 23 ... Phosphor screen 24 ... Shadow mask 25 ... Neck 30 ... 6 pole magnet plate 31 ... 4 pole magnet plate 32 ... Convergence magnet 33 (a, b) ... 1st magnetic body 36 ... Deflection device 37 ... 2-pole magnet 40 ... in-line type electron gun structure 41 (R, G, B) ... electron beam 46 ... cathode 60 (a, b) ... second magnetic body 61 (a, b) ... second magnetic body

Claims (16)

[Claims] 1. An envelope comprising a panel having a phosphor surface formed on an inner surface thereof and a neck connected to the panel via a funnel, and three electron beams provided in the neck and arranged on a horizontal axis. An electron gun assembly including a cathode that emits in a tube axis direction toward the panel side; and a multipole magnet plate attached to the outside of the neck to generate a multipole magnetic field on the trajectory of the electron beam emitted from the cathode. And a multi-pole magnetic field generating means having at least the horizontal axis as the X axis, the tube axis as the Z axis, and the vertical axis orthogonal to the horizontal axis and the tube axis as the Y axis.
A pair of band-shaped first magnetic bodies that are attached to face each other with the electron gun body therebetween so as to be symmetric with respect to the YZ plane, and extend in the tube axis direction; A second magnetic body symmetrically arranged with respect to an XZ plane, wherein the first magnetic body, the second magnetic body, and the multipolar magnet plate emit the light emitted from the cathode. A positive magnetic field component from the one first magnetic body toward the other first magnetic body along the Z-axis direction on the trajectory of the center beam of the three electron beams; Forming a magnetic field distribution having a negative magnetic field component from the body toward the one first magnetic body, wherein the cathode is a sum of positive magnetic field components on the trajectory of the center beam at a position along the Z-axis direction. And the sum of the negative magnetic field components are almost equal Color picture tube, characterized in that disposed in that position. 2. The magnetic field distribution on the center beam trajectory has a plurality of intensity peaks in which the positive magnetic field component and the negative magnetic field component are alternately repeated. 2. The color picture tube according to claim 1, wherein the color picture tube is arranged at a position between the eye intensity peak and the third intensity peak. 3. A sum of magnetic field components including a first intensity peak from the panel side acting on the center beam among the intensity peaks of the magnetic field distribution, and a second intensity peak. 3. The color picture tube according to claim 2, wherein the sum of the magnetic field components is substantially equal. 4. The color picture tube according to claim 2, wherein said magnetic field distribution has three intensity peaks which alternately repeat said positive magnetic field component and said negative magnetic field component. 5. The apparatus according to claim 1, wherein the pair of first magnetic bodies are provided on an outer surface of the neck so as to cover a position of a cathode of the electron gun assembly provided in the neck. 2. The color picture tube according to 1. 6. The color picture tube according to claim 1, wherein said pair of first magnetic bodies are provided integrally with said multipole magnetic field generating means. 7. The multipole magnetic field generating means includes a cylindrical holder mounted on the neck, a ring-shaped first magnet plate for generating a quadrupole magnetic field, and a ring-shaped first magnet plate for generating a hexapole magnetic field. 2. The color picture tube according to claim 1, further comprising two magnet plates, wherein the pair of first magnetic bodies are provided on an inner surface of the holder 50. 3. 8. An electron gun assembly comprising: three cathodes arranged in a line on the horizontal axis; and a plurality of electrodes arranged from the cathodes in the tube axis direction. 2. The color picture tube according to claim 1, wherein the color picture tube is an in-line type electron gun structure that emits three electron beams in an array. 9. The second magnetic body is formed so as to be discontinuous in the vicinity of an X-axis, and has an X-Y plane within an XY plane.
2. The color picture tube according to claim 1, comprising a pair of arc-shaped magnetic bodies symmetrically arranged with respect to the -Z plane. 10. A pair of cylinders formed so as to be discontinuous in the vicinity of the X axis and symmetrically arranged in the XY plane with respect to the XZ plane. 2. The color picture tube according to claim 1, wherein said color picture tube is made of a magnetic material. 11. The second magnetic body has an X-Y plane in an XY plane.
2. The color picture tube according to claim 1, wherein the color picture tube is made of an integral magnetic body formed in a ring shape symmetric with respect to the Z plane. 12. A color picture tube according to claim 1, wherein said second magnetic body is formed to have substantially the same curvature as the inner surface of said multi-pole magnet plate. 13. The second magnetic body, when the intersection of the X-axis, Y-axis, and Z-axis is set as the origin near the multi-pole magnet plate, the center is centered on the origin in the XY plane. The center angle from the Y axis near the Y axis on the circle
2. The color picture tube according to claim 1, comprising a pair of magnetic materials arranged symmetrically about an XZ plane over a range of 5 degrees or more and 40 degrees or less. 14. The color picture tube according to claim 1, wherein said second magnetic body is provided integrally with said multipole magnetic field generating means. 15. The multipole magnetic field generating means includes: a cylindrical holder; a ring-shaped first magnet plate for generating a quadrupole magnetic field; a ring-shaped second magnet plate for generating a hexapole magnetic field; A spacer provided between the first and second magnet plates, wherein the second magnetic body comprises:
2. The color picture tube according to claim 1, wherein the color picture tube is provided so as to face an inner surface of the cylindrical holder. 16. The second magnetic body has an X-Y plane in an XY plane.
16. The multi-pole magnetic field generating means is made of an integral magnetic body formed in a ring shape symmetrical with respect to the Z plane and provided as a spacer of the multipole magnetic field generating means.
2. The color picture tube according to 1.