JPH113670A - Color picture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color picture tube having good operability and excellent adjustment efficiency. SOLUTION: In a convergence magnet 32, a pair of magnetic bodies 33a, (33b) extending in the Z-axis direction are disposed so as to face opposite to each other in the X-axis direction for shielding against an external magnetic field acting on three electron beams arranged in a line. Relative positions in the Z-axis direction of the magnetic bodies to the center of a ring-shaped six- pole magnet plate 30 are established such that a ratio of a length of the magnetic bodies in front of the six-pole magnet plate to a length of the magnetic bodies at the rear falls between 30:70 and 75:25. With this, a force component acting on a center beam can be reduced without reducing force components acting on two side beams and undesired movement of the center beam can be prevented.

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 and having improved convergence characteristics.

[0002]

2. Description of the Related Art Generally, an in-line type color picture tube is
As shown in FIG. 1 and FIG. 2, there is provided an envelope composed of a panel 1 and a funnel 1 connected to the panel 1. On the inner surface of the panel 1, a phosphor screen 3 composed of a three-color phosphor layer that emits red (R), green (G), and blue (B) light is provided. Mask 4
Is arranged.

In the neck 5 of the funnel 2, an in-line type electron gun that emits three electron beams arranged on the same horizontal axis, that is, the X axis is arranged.
Further, at the rear end of the deflecting device 6 mounted on the outer periphery from the funnel 2 to the neck 5, a pair of N-pole and S-pole magnets 7 arranged so as to face each other is arranged. I have. This two-pole magnet 7 is used for landing adjustment.

[0004] A convergence magnet 8 is arranged outside the neck 5. The convergence magnet 8 includes a pair of ring-shaped magnet plates 11 for generating at least a four-pole static magnetic field composed of two sets of N poles and S poles, and a six-pole static magnetic field composed of three sets of N poles and S poles. A pair of ring-shaped magnet plates 1 for generating a magnetic field
0.

[0005] As described above, the two-pole magnet 7 and the convergence magnet 8 are arranged so that, when there is no deflection, three electron beams emitted from the electron gun in one row, that is, a green electron beam as a center beam and a red electron beam as a side beam. The beam and the electron beam for blue are aligned at the center of the phosphor screen 3 and adjusted so as to achieve sufficient color purity and convergence.

Then, the three electron beams are deflected and scanned by the deflecting device 6 to reproduce a color image on the phosphor screen 3. In such an in-line type color picture tube, since a magnetic material is used for a cathode portion of an electron gun, an electron beam is easily affected by an external magnetic field such as geomagnetism. In addition, when the antenna is used by being arranged in a different direction from that at the time of adjustment or in an area where geomagnetic conditions are different, conditions of the external magnetic field are different.

For example, in the use environment, when an external static magnetic field such as terrestrial magnetism interlinks in the direction of the tube axis of the neck, that is, in the Z-axis direction, each of the three electron beams has a direction opposite to the side beam. Of force acts. That is,
For each side beam, the vertical direction, Y
Since a force acts in the positive direction and the negative direction in the axial direction, there arises a problem that the red image and the blue image displayed on the fluorescence facing surface by the side beam are relatively shifted up and down. For this reason, in order to shield an external magnetic field in the tube axis direction, a pair of magnetic bodies 9 long along the tube axis direction are arranged on both outer sides on the horizontal axis of the neck.

As shown in FIG. 2, the magnetic body 9 is fixed to the inner surface of the cylindrical holder H of the convergence magnet 8 along the tube axis direction so as to be as close as possible to the trajectory of the electron beam.

On the other hand, the six-pole magnet plate 10 is formed in a shape as shown in FIG. 3 by a total of six poles of N poles and S poles arranged at equal intervals and alternately on a ring-shaped magnet plate. Generates a magnetic field. This magnetic field applies a force in the same direction to the electron beams on both sides, that is, the side beams, depending on its shape, and can change the trajectory of the side beams. 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.

[0010]

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 in the dimensions, as shown in FIG. 2, a position occurs where the magnetic body and the magnet plate partially overlap in the tube axis direction.

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, and the following problems occur. Occurs.

FIG. 4 shows the distribution of the magnetic field formed by the six-pole magnet plate when the electron beam is corrected in the upward direction of the vertical axis, that is, the + direction in the Y-axis direction, and how the magnetic material is magnetized. I have.

In this case, the north pole and the south pole of the six-pole magnet plate 10 are positioned so as to face each other on the horizontal axis, that is, the X axis. At this time, the magnetic bodies 9a and 9b opposed to each other on the X axis are arranged close to the N pole and the S pole of the six-pole magnet plate 10, respectively. For this reason, 6
A magnetic body 9a close to the pole of the pole magnet plate 10,
The portion 9b is magnetized to the polarity opposite to the polarity of the magnet plate. 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, an S pole is generated on the surface of the magnetic body 9a located on the + side of the X axis, which is in contact with the N pole of the magnet plate, and N poles are generated on 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 minus side of the X axis and in contact with the S pole of the magnet plate, and S poles are generated at the front end and the rear end of the magnetic body 9b.

As a result, a magnetic field from the magnetic body 9a to the magnetic body 9b, that is, a magnetic field from the + side to the-side along the X-axis direction is formed at the rear end of the magnetic bodies 9a and 9b. By such a magnetic field, an upward force acts on the electron beam passing through the rear end of the magnetic material.

In the vicinity of the surface of the magnet plate 10, the magnetic flux of the pole located on the X axis is guided to the magnetic material, so that the magnetic field formed by the magnet plate 10 from the + side to the-side on the X axis is Weakens. Magnet plate 10
Is designed such 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 horizontal axis and the four poles near the Y axis in a state where the magnetic body is not disposed, as described above. However, when a magnetic body is disposed, the magnetic field on the X axis is weakened.
The magnetic field from the minus side to the plus side in the X-axis direction where the four poles near the axis are generated becomes relatively strong. That is, at the front end of the magnetic body, a magnetic field is generated from the + side to the − side on the X axis similarly to the rear end, but from the − side to the + side in the X axis direction where four poles near the Y axis are generated. Is strong, a magnetic field is generated on the orbit of the center beam from the minus side to the plus side in the X-axis direction as the sum of the magnetic fields.

That is, on the trajectory of the side beam near the magnet plate 1, a magnetic field in the X + direction is generated from the X + direction, and on the trajectory of the center beam, a magnetic field in the X + direction is generated. The directions of the magnetic fields of the magnets on the track are opposite to each other.

Therefore, considering the effect of the magnetic field on the electron beam on the magnet surface, the side beam is directed upward.
The center beam receives the electromagnetic force in the opposite direction downward.

As a result, when adjusting the trajectory of the electron beam using the six-pole magnet, the center beam does not move when there is no magnetic material, and both side beams are moved to the + side in the Y-axis direction by 1.3.
When a magnetic material is mounted on a magnet plate that can be moved by 0.5 mm, both side beams
m, the center beam is 0.8 mm on the negative side in the Y-axis direction.
Moving.

This not only deteriorates the operability of the magnet plate, but also causes the center beam to move at the time of six-pole correction after the landing adjustment by the two-pole magnet. Therefore, it is necessary to adjust the landing again by the two-pole magnet. Occurs, 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 is reduced, and the center beam moves in the direction opposite to the side beam. Occurs. SUMMARY OF THE INVENTION It is an object of the present invention to provide a color picture tube having good operability and excellent adjustment efficiency.

[0021]

SUMMARY OF THE INVENTION The present invention has been made based on the above problems, and has an envelope including a panel having a phosphor surface formed on an inner surface thereof and a neck connected to the panel via a funnel. An electron gun including a cathode provided in the neck and emitting a plurality of electron beams arranged on a horizontal axis in a tube axis direction toward the panel, and attached to the outside of the neck and near the electron gun. A convergence magnet having at least a magnet plate that generates a six-pole magnetic field, and a pair of convergence magnets mounted on the horizontal axis outside the neck so as to face each other with the electron gun interposed therebetween and extending in the tube axis direction. And a ratio of the length of the cathode side to the length of the panel side from the position of the magnet plate is 3
A color picture tube is provided, wherein the color picture tube is arranged to be in the range of 0:70 to 75:25.

According to the color picture tube of the present invention, the magnetic material is arranged so that the ratio of the length of the cathode side to the length of the panel side from the position of the magnet plate is in the range of 30:70 to 75:25. ing. Therefore, it is possible to suppress the magnetic field acting on the center beam without reducing the magnetic field acting on both side beams of the center beam among the plurality of electron beams emitted from the electron gun,
Unwanted movement of the center beam can be reduced.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color picture tube according to the present invention, in particular, an in-line type color picture tube provided with an in-line type electron gun will be described in detail with reference to the drawings. As shown in FIGS. 5 and 6, the in-line type color picture tube according to this embodiment has a panel 21, a funnel 21 connected to the panel 21, and a neck as a small-diameter end connected to the funnel 21. 25. On the inner surface of the panel 21, a phosphor screen 23 composed of a three-color phosphor layer that emits red (R), green (G), and blue (B) light is provided.
A shadow mask 24 having a large number of electron beam passage holes is arranged so as to be close to and opposed to 3.

As shown in FIG. 6, an in-line type electron gun 40 for emitting three electron beams arranged on the same horizontal axis, that is, the X axis, is provided inside the envelope neck 25. Are located. This in-line type electron gun 40
Comprises a plurality of cathodes arranged in a line, in which a heater is provided, and has a plurality of electrodes for controlling, focusing, and accelerating the electron beam from each cathode in order from the cathode in the direction of the phosphor screen. Together with the insulating support. A stem pin 34 for supplying a predetermined voltage to the in-line type electron gun 40 is attached to the rear end of the neck 25.

Further, a deflecting device 36 is mounted on the outer periphery from the funnel 22 to the neck 25. 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.

By combining the in-line type electron gun 40 with a deflecting device for forming a non-uniform magnetic field, the three electron beams 41R, 41G,
1B can be achieved on the fluorescent screen 23 formed on the inner surface of the panel 21, so-called self-convergence can be achieved.

At the rear end of the deflecting device 36, a ring-shaped two-pole magnet 37 composed of a pair of N poles and S poles arranged to face each other is arranged. 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.

A convergence magnet 32 is arranged outside the neck 25. The convergence magnet 32 includes at least a pair of ring-shaped magnet plates 31 that generate a four-pole static magnetic field composed of two sets of N poles and S poles, and six pairs of three sets of N poles and S poles.
It has a pair of ring-shaped magnet plates 30 that generate a pole static magnetic field. The static magnetic field formed by the four-pole magnet plate 31 and the six-pole magnet plate 30 controls the side beam, particularly the side beam, of the three electron beams arranged in a row in the horizontal and vertical directions, and the green electron beam as the center beam. The three electron beams are aligned so that the side beams, that is, the red electron beam 41R and the blue electron beam 41B, are evenly arranged on both outer sides of 41G.

As described above, the two-pole magnet 37 and the convergence magnet 32 allow the electron gun 4
The three electron beams in a single row emitted from 0 are adjusted so that sufficient color purity and convergence can be achieved at the center of the phosphor screen 3.

Then, the three electron beams are deflected by a deflecting device 36.
The color image is reproduced on the phosphor screen 3 by deflecting and scanning. In such an in-line type color picture tube, as shown in FIG. 7, in order to shield an external magnetic field such as terrestrial magnetism which adversely affects an electron beam emitted from an electron gun, particularly an external magnetic field along the Z-axis direction. A pair of magnetic bodies 33a and 33b long along the Z-axis direction are arranged on both outer sides of the neck 25 on the X-axis.

That is, the convergence magnet 3
Reference numeral 2 has a ring-shaped magnet plate for generating a static magnetic field, which is attached to a cylindrical holder 50 for attachment to the neck 25. The convergence magnet 32 has at least a six-pole magnet plate 30.
And a four-pole magnet plate 31.

Each of the 6-pole magnet plate 30 and the 4-pole magnet plate 31 is a pair of two plates.
When the handles for adjusting the opening angle are combined, the two magnetic fields cancel each other, and the magnetic field generated by the magnet is minimized. The quadrupole magnet plate 31 generates the maximum magnetic field when the opening angle is 90 degrees. The six-pole magnet plate 30 generates a maximum magnetic field when the opening angle is 60 degrees.

In the convergence magnet 32, the six-pole magnet plate 30, the four-pole magnet plate 31,
And a fixing ring are arranged in order. Further, a first division spacer is arranged between the six-pole magnet plate 30 and the four-pole magnet plate 31, and a second division spacer is arranged between the four-pole magnet plate 31 and the fixing ring. ing.

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

The magnetic members 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 magnetic bodies 33a, 33b
Is provided on the outer wall of the neck 25.

In this embodiment, the magnetic members 33a, 33
b is formed using a cold-rolled silicon steel sheet, as an example of its dimensions, a sheet pressure of 0.35 mm, a length of 35 mm,
The width is 4 mm.

The magnetic bodies 33a and 33b are 18 mm from the center of the six-pole magnet plate 30 in the Z-axis direction to the deflection device side whose front end is forward, that is, on the minus side on the Z-axis.
, And the rear end thereof is located at a position of 17 mm rearward, that is, on the stem pin side on the + side on the Z axis. That is, the front-rear ratio, that is, the ratio of the length in front of the center of the six-pole magnet plate in the Z-axis direction to the entire length of the magnetic body is about 51%.

FIG. 8 shows the positional relationship between the six-pole magnet plate and the magnetic body when the electron beam is corrected in the upward direction of the vertical axis, that is, in the + direction of the Y-axis direction. In this case, the six-pole magnet plate 3 is placed on the horizontal axis, that is, the X axis.
The N and S poles of 0 are located so as to face each other. At this time,
Magnetic bodies 33a and 33b arranged facing each other on the X axis
Are located near the N-pole and S-pole of the six-pole magnet plate 30, respectively. For this reason, the portions of the magnetic bodies 33a and 33b close to the poles of the six-pole magnet plate 30 are magnetized to the opposite polarity to the poles of the magnet plate. 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 on the Z-axis side, and the rear end of the magnetic body, that is, the end on the Z-axis + side. Generates a two-pole magnetic field.

That is, at a substantially central portion of the magnetic body 33a,
An S pole is formed by the action of the N pole of the magnet plate 30, and N poles are formed at the front end and the rear end. Also,
A magnet plate 30 is provided substantially at the center of the magnetic body 33b.
The N pole is formed by the action of the S pole, and the S pole is formed at the front end and the rear end.

As a result, a magnetic field from the magnetic body 33a toward the magnetic body 33b, that is, a magnetic field from the + side to the-side along the X-axis direction is formed at the front end and the rear end of the magnetic bodies 33a and 33b. By such a magnetic field, the magnetic body 33
An upward force acts on the electron beam passing through the front end and rear end of a and 33b.

In the vicinity of the surface of the magnet plate 10, the magnetic flux of the pole located on the X axis is generated by the magnetic members 33a and 33b.
, The magnetic field formed by the magnet plate 30 from the + side to the − side on the X axis is weakened. As described above, the magnet plate 30 is set 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 horizontal axis and the four poles near the Y axis in a state where the magnetic material is not arranged. Although it is designed, when a magnetic material is disposed, the magnetic field on the X axis weakens, so that the magnetic field from the minus side to the plus side in the X axis direction where four poles near the Y axis in the magnet plate 30 are generated is relatively high. Become stronger. In other words, a magnetic field from the + side to the-side on the X axis is generated at substantially the center of the magnetic bodies 33a and 33b as in the front end and the rear end.
Since the magnetic field from the negative side to the positive side in the X-axis direction generated by the four poles near the axis is strong, the total magnetic field is generated from the negative side to the positive side in the X-axis direction.

FIG. 9 shows an intensity distribution curve of a horizontal magnetic field on each trajectory of three electron beams arranged in a line in a conventional color picture tube. FIG. 10 shows the color picture tube of this embodiment. The intensity distribution curve of the horizontal magnetic field on each orbit of the three electron beams arranged in a row is shown.

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.

In the example shown in FIG. 9, the magnetic material is arranged so that the front end is located at a position of -5 mm and the rear end is located at a position of +30 mm. That is, the front-to-back ratio is about 14%.

In the example shown in FIG. 10, the magnetic material is arranged such that the front end is located at the position of -18 and the rear end is located at the position of +17 mm. That is, the front-to-back ratio is 5
1%.

In FIGS. 9 and 10, the integrated value of each magnetic field distribution curve corresponds to the magnetic field intensity acting on each electron beam, and this determines the amount of movement of the electron beam in the Y-axis direction. In the example shown in FIG. 9, the positive magnetic field strength is strong near the front end of the magnetic material on the trajectory of the center beam, that is, in the region from −5 mm to around 0, and the rear end of the magnetic material is The negative magnetic field is strong near the position, that is, in the region of 10 mm or more. Relatively, since the positive magnetic field strength is stronger, a downward force on the center beam, that is, a negative force in the Y-axis direction acts on the center beam. Therefore, in order to reduce the amount of movement of the center beam, it is necessary to reduce this positive magnetic field strength.

In the example shown in FIG. 10, a negative magnetic field is generated on the stem pin side on the trajectory of the center beam.
A positive magnetic field is generated near the pole magnet, and a negative magnetic field is generated on the deflecting device side. Then, relatively positive and negative magnetic field strengths cancel each other. Therefore, it is possible to minimize the force acting on the center beam.

In this embodiment, the moving amount 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 amount of change in landing at this time is 2 μm,
It is within the range of the allowable adjustment error.

Next, another case of the front-rear ratio will be described. In the case where the magnetic material is arranged at a position of 12 mm in front and 23 mm in back so that the front-to-back ratio of the magnetic body to the center position of the 6-pole magnet plate is 35% front and 65% rear,
The amount of movement of the electron beam is as follows.
When the center beam is 1.3 mm, the center beam is 0.4 mm on the − side in the Y-axis direction, and the amount of change in the landing is 4 mm.
Improves to μm.

Further, the front-back ratio of the magnetic body to the center position of the six-pole magnet plate is 30% in front and 70% in back.
10.5mm forward and 23.5m backward so that
m, the center beam is 0.5 mm on the negative side in the Y-axis direction when both side beams are 1.3 mm on the positive side in the Y-axis direction. Is improved to 5 μm.

Further, the front-back ratio of the magnetic body to the center position of the six-pole magnet plate is 65% in front and 35% in back.
When the electron beam is arranged at a position of 23 mm forward and 12 mm rearward, the moving amount of the electron beam is such that when both side beams are 1.3 mm on the + side in the Y axis direction, the center beam is in the Y axis direction. Is 0.3 mm on the negative side, and the variation in landing is improved to 3 μm.

The relationship between the front-to-back ratio of the magnetic material and the amount of beam movement is summarized as follows. FIG. 11 shows the relationship between the front-to-back ratio of the magnetic body and the movement amount of the center beam. The horizontal axis indicates the front-to-back ratio of the magnetic material, and the vertical axis indicates the movement amount of the center beam.

As shown in FIG. 11, in order to set the moving amount of the center beam to 0.5 mm or less within the range of the allowable adjustment error, the position of the magnetic body must be set at the center position of the six-pole magnet plate. It is desirable to arrange the magnetic material so that the front-to-back ratio of the body is in the range of 30% to 75%, preferably 40% to 60%. In other words, the magnetic body is located in the central region of the magnetic body, that is, the Z of the magnetic body.
20% of the total length before and after the center of the axial length,
It is desirable that the center of the six-pole magnet plate be located within a region corresponding to 10% of the entire length.

As described above, according to the color picture tube of the present invention, in order to correct the trajectory of the electron beam in the vertical direction when the magnetic body is mounted, the color cathode ray tube is arranged to shield the external magnetic field acting on the electron beam. The magnetic material is arranged such that the center position of the six-pole magnet plate is in the range of 30% or more and 75% or less, preferably 40% or more and 60% or less. Thereby, 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. This allows
With little force applied to the center beam,
A force can be applied to the side beam in the vertical direction.

For this reason, the operability of the convergence magnet is improved, and the center beam can be prevented from moving at the time of six-pole correction after the landing adjustment by the two-pole magnet. Therefore, it is necessary to adjust the landing again by the two-pole magnet. As a result, an in-line type color picture tube excellent in adjustment efficiency can be provided.

[0056]

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 the six-pole magnet plate shown in FIG. 2;

FIG. 4 is a diagram illustrating a relationship between arrangement positions of a convergence magnet and a magnetic body illustrated in FIG. 2;

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 provided in a neck of the in-line type color picture tube shown in FIG.

FIG. 7 is a perspective view schematically showing a convergence magnet of the in-line type color picture tube of the present invention shown in FIG. 5;

FIG. 8 is a diagram illustrating a relationship between arrangement positions of a convergence magnet and a magnetic body illustrated in FIG. 7;

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 graph showing a relationship between a front-to-back ratio of a magnetic body and an amount of movement of a center beam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Panel 22 ... Funnel 23 ... Phosphor screen 24 ... Shadow mask 25 ... Neck 36 ... Deflection device 37 ... 2-pole magnet 30 ... 6-pole magnet plate 31 ... 4-pole magnet plate 32 ... Convergence magnet 33 (a, b) ... Magnetic Body 40: In-line type electron gun 41 (R, G, B): Electron beam

Claims (8)

[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 a plurality of electrons provided in the neck and arranged on a horizontal axis. An electron gun including a cathode for emitting a beam in a tube axis direction toward the panel; a convergence magnet mounted outside the neck and having at least a magnet plate for generating a six-pole magnetic field near the electron gun; A pair of magnetic members attached to the outer side of the horizontal axis so as to face each other with the electron gun interposed therebetween and extending in the tube axis direction, wherein the magnetic member is positioned at the position of the magnet plate. And the ratio of the length of the cathode side to the length of the panel side is 30:
A color picture tube, which is arranged so as to fall within a range of 70 to 75:25. 2. An enclosure comprising a panel having a phosphor surface formed on an inner surface thereof and a neck connected to the panel via a funnel; and a plurality of electrons provided in the neck and arranged on a horizontal axis. An electron gun including a cathode for emitting a beam in a tube axis direction toward the panel; a convergence magnet mounted outside the neck and having at least a magnet plate for generating a six-pole magnetic field near the electron gun; A pair of magnetic members attached to the outer side of the horizontal axis so as to face each other with the electron gun interposed therebetween and extending in the tube axis direction, wherein the magnetic member is positioned at the position of the magnet plate. And the ratio of the length of the cathode side to the length of the panel side is 40:
A color picture tube, which is arranged so as to fall within a range of 60 to 60:40. 3. The color picture tube according to claim 1, wherein the magnetic body is provided on an outer surface of the neck. 4. The color picture tube according to claim 1, wherein said magnetic material is provided integrally with said convergence magnet. 5. The convergence magnet comprises a cylindrical holder, a ring-shaped first magnet plate for generating a quadrupole magnetic field, and a ring-shaped second magnet plate for generating a hexapole magnetic field.
3. The apparatus according to claim 1, further comprising a magnet plate and a spacer provided between the first and second magnet plates, wherein the magnetic body is disposed on an inner surface of the cylindrical holder. 2. The color picture tube according to 1. 6. 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 a plurality of electrons provided in the neck and arranged on a horizontal axis. An electron gun including a cathode for emitting a beam in a tube axis direction toward the panel; a convergence magnet mounted outside the neck and having at least a magnet plate for generating a six-pole magnetic field near the electron gun; A pair of magnetic bodies attached to the outer side of the horizontal axis so as to sandwich the electron gun with the electron gun interposed therebetween, and extending in the tube axis direction, and along the tube axis direction of the magnetic body. A color picture tube, wherein the magnet plate is located in a central region. 7. The magnetic recording medium according to claim 7, wherein the central region extends from the center of the magnetic body in the tube axis direction to the cathode side and the panel side in a length of 20% of the total length of the magnetic body. 7. The color picture tube according to 6. 8. 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 enclosures provided in the neck and arranged on a horizontal axis. An in-line type electron gun that emits a three-electron beam including a cathode and a plurality of electrodes arranged in a tube axis direction toward the panel of the cathode, and a three-electron beam emitted from the in-line type electron gun. A deflecting device for deflecting in the direction and the vertical direction, a convergence magnet attached to the outside of the neck and having at least a magnet plate for generating a six-pole magnetic field near the electron gun, and on the horizontal axis outside the neck. An external magnetic field attached to the electron gun so as to oppose each other and acting on both side electron beams of the three electron beams near the cathode; And a pair of magnetic bodies extending in the tube axis direction to adjust the horizontal axis direction component, wherein the magnetic body has a length on the cathode side and a length on the panel side from the position of the magnet plate. Is 30:
A color picture tube, which is arranged so as to fall within a range of 70 to 75:25.