JP2000294164A - Electron beam converging method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam converging method and its device capable of easily converging an electron beam and easy to manufacture. SOLUTION: A main magnetic field wherein a forward magnetic field having a magnetic field in the radiation direction of a green beam 33 and a backward magnetic field having a magnetic field in a direction reverse to the forward magnetic field are arranged on the same axis is formed with a cylindrical permanent magnet 38 magnetized in the axial direction. The permanent magnet 38 is installed in the circumferential part of a neck part 31 of a color cathode- ray tube 21 that is a position adjacent to the side generating electron beams 25 of an inline type electron gun 35 of the color cathode-ray tube 21. The green beam 33 passes the center axis of the permanent magnet 38. The electron beams 25 are deflected by varying at least one or more of the band width, direction and position of the main magnetic field formed by the permanent magnet 38. The three electron beams 25 are converged in an opening part 29 of a shadow mask 30. The convergence adjustment of the three electron beams 25 can easily be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for deflecting an electron beam generated from an in-line type electron gun of a color cathode ray tube to focus the electron beam on an opening of a shadow mask.

[0002]

2. Description of the Related Art Conventionally, as an electron beam converging device for deflecting an electron beam generated from an in-line type electron gun of a color cathode ray tube and converging the electron beam on an opening of a shadow mask, for example, a structure shown in FIGS. Are known.

The electron beam focusing apparatus shown in FIGS. 33 to 39 includes a magnetic field forming means 2 for forming a magnetic field for deflecting the electron beam 1. The magnetic field forming means 2 is formed in a substantially annular sheet shape as shown in FIGS. 33 (a) and 33 (b), and the inner peripheral portion 3 has four poles at equal intervals as shown in FIGS. 34 and 35. 36 and 37, and a six-pole permanent magnet 5 whose inner peripheral portion 3 is magnetized to six poles at equal intervals as shown in FIGS. 36 and 37. A knob 6 used for rotating the four-pole permanent magnet 4 and the six-pole permanent magnet 5 around the axis is provided on an outer peripheral portion of the four-pole permanent magnet 4 and the six-pole permanent magnet 5. The magnetic field forming means 2 is composed of two coaxially superposed
The four-pole permanent magnets 4 and the six-pole permanent magnets 5 superposed coaxially are arranged coaxially.

[0004] The two quadrupole permanent magnets 4 are arranged in advance so that the magnetic fields generated by the quadrupole permanent magnets 4 cancel each other. Similarly, the two six-pole permanent magnets 5 are also arranged so that the magnetic fields generated by the respective six-pole permanent magnets 5 are canceled in advance.

The magnetic field forming means 2 is located at a position near the in-line type electron gun mounted on the neck of the color cathode ray tube, and is attached to the outer periphery of the neck of the color cathode ray tube. As shown in FIGS. 38 and 39, this in-line type electron gun generates three electron beams 1 of a red beam 7, a green beam 8 and a blue beam 9 at equal intervals in parallel. Further, the in-line type electron gun is formed so that the red beam 7 and the blue beam 9 are generated from both sides of the position where the green beam 8 is generated. Further, the magnetic field forming means 2 is located at a position near the side of the in-line type electron gun that generates the electron beam 1 and is coaxially mounted in the irradiation direction of the green beam 8.

Here, the three electron beams 1 pass through the inner periphery 3 of the two four-pole permanent magnets 4 and the two six-pole permanent magnets 5, and the green beam 8 is The three electron beams 1 are generated from an in-line type electron gun so as to pass on the central axes of the four-pole permanent magnet 4 and the two six-pole permanent magnets 5. Then, three electron beams 1 become 2
As shown in FIG. 38, when passing through the four quadrupole permanent magnets 4, the magnetic field of the quadrupole permanent magnets 4 causes the red beam 7 and the blue beam 9 to move away from the green beam 8. , Respectively. When the three electron beams 1 pass through the six-pole permanent magnet 5, as shown in FIG. 39, the red beam 7 and the blue beam 9 are moved in the same direction by the magnetic field generated by the six-pole permanent magnet 5. Is deflected to

Then, the two four-pole permanent magnets 4 and the two six-pole permanent magnets 5 are appropriately displaced using a knob 6, and the magnetic field of the four-pole permanent magnets 4 and the six-pole permanent magnets 5 is reduced. Change direction and strength. Then, the electron beam converging device 10 converges the three electron beams 1 on the openings of the shadow mask of the color cathode ray tube.

[0008]

However, the electron beam focusing device 10 shown in FIGS.
When the three electron beams 1 are deflected and focused using the two four-pole permanent magnets 4 and the two six-pole permanent magnets 5,
The irradiation direction of the green beam 8 is shifted due to the non-uniformity of the magnetic poles of the pole permanent magnet 4 and the six-pole permanent magnet 5 and the positional accuracy of the in-line type electron gun. To do this, two 4-pole permanent magnets 4
Further, since it is necessary to repeatedly adjust each of the two six-pole permanent magnets 5 as needed, the adjustment operation for converging the three electron beams 1 is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an electron beam focusing method and an electron beam focusing method which can easily adjust the focusing of the electron beam and can be easily manufactured.

[0010]

According to a first aspect of the present invention, there is provided a method for focusing an electron beam, comprising three red, green, and blue beams generated from an in-line type electron gun mounted on a neck portion of a color cathode ray tube. Focusing the electron beam on the opening of the shadow mask of the color cathode ray tube,
In the electron beam focusing method of irradiating the red, green, and blue beams on the three-color fluorescent film of the screen of the color cathode-ray tube, respectively, the in-line type electron gun is positioned at a position near the electron beam generating side. ,
A main magnetic field, wherein at least one or more of a forward magnetic field having a magnetic field in a direction of irradiation of the green beam and a reverse magnetic field having a magnetic field in a direction opposite to the forward magnetic field are coaxially arranged in the direction of irradiation of the green beam; Forming, the bandwidth of this main magnetic field, direction, intensity, and changing at least one or more of the position to deflect the red beam, the green beam, and at least one or more of the blue beam, The red beam, the green beam, and the blue beam are focused on an opening of the shadow mask.

[0011] At least one of a forward magnetic field having a magnetic field in the irradiation direction of the green beam generated from the in-line type electron gun and at least one of a reverse magnetic field having a magnetic field in the opposite direction to the forward magnetic field is applied to the green beam. Arranged coaxially,
A main magnetic field is formed at a position near the side of the in-line type electron gun that generates an electron beam, and the bandwidth, direction, strength, and at least one of the positions of the main magnetic field are appropriately changed, At least one of the three electron beams is deflected, and the three electron beams are focused on the opening of the shadow mask of the color cathode-ray tube. Therefore, the focus adjustment of the three electron beams is simplified, and the adjustment work is performed. It will be easier.

According to a second aspect of the present invention, there is provided a method for focusing an electron beam.
2. The electron beam focusing method according to claim 1, wherein the main magnetic field is provided on a substantially cylindrical first coil connected to a first power supply unit, and on a second power supply disposed coaxially with the first coil. At least one or more of the substantially cylindrical second coil connected to the portion, coaxial and red beam in the irradiation direction of the green beam,
It is a position where the green beam and the blue beam pass through the inner peripheral portion, and is formed by being disposed on the outer peripheral portion of the neck portion of the color cathode ray tube.

When the main magnetic field is formed by using the substantially cylindrical first coil and the substantially cylindrical second coil, the value of the current flowing through the first coil is determined by the first coil. And the value of the current flowing through the second coil is adjusted by the first power supply unit connected to the second coil.
When appropriately adjusted by the second power supply unit connected to the coil, the red, green, and blue beams generated from the in-line type electron gun are deflected and focused on the opening of the shadow mask. Accordingly, since the three electron beams are focused only by appropriately adjusting the currents flowing through the first coil and the second coil, the focusing adjustment of the three electron beams is simplified.

According to a third aspect of the present invention, there is provided a method for focusing an electron beam.
2. The electron beam focusing method according to claim 1, wherein the main magnetic field comprises at least one or more permanent magnets formed in a substantially cylindrical shape and magnetized along the axial direction, and are coaxial with the green beam irradiation direction and red. It is a position where the beam, the green beam and the blue beam pass through the inner peripheral portion, and is formed by being disposed on the outer peripheral portion of the neck portion of the color cathode ray tube.

When the main magnetic field is formed by using a substantially cylindrical permanent magnet magnetized along the axial direction, the size of the permanent magnet and the magnetic field formed by the permanent magnet are constant. When the permanent magnet is appropriately moved along the axial direction, the three electron beams generated from the in-line type electron gun are deflected and focused on the opening of the shadow mask, so that the permanent magnet is moved along the axial direction. Since the three electron beams are focused only by moving, the focusing of the three electron beams can be easily adjusted.

According to a fourth aspect of the present invention, there is provided a method of focusing an electron beam.
2. The electron beam focusing method according to claim 1, wherein the main magnetic field is provided on a substantially cylindrical first coil connected to a first power supply unit, and on a second power supply disposed coaxially with the first coil. At least one or more of a substantially cylindrical second coil connected to the portion and a permanent magnet formed in a substantially cylindrical shape and magnetized along the axial direction, on the same axis in the green beam irradiation direction and It is a position where the red beam, the green beam, and the blue beam pass through the inner peripheral portion, and is formed on the outer peripheral portion of the neck portion of the color cathode ray tube.

When a main magnetic field is formed by using at least one of the first coil and the second coil and at least one of the permanent magnets, first, the three electron beams are located at positions where they are substantially converged. When the permanent magnet is positioned and fixed, and a current of an appropriate value is applied to each of the first coil and the second coil to change the main magnetic field to focus three electron beams, the three electron beams are Since the convergence is adjusted substantially by the main magnetic field formed by the permanent magnet, the amount of current supplied from the first power supply unit and the second power supply unit to the first coil and the second coil can be reduced. Focus adjustment of the beam is facilitated. When the permanent magnet is appropriately moved along the axial direction to focus the three electron beams, and then a current of an appropriate value is supplied to each of the first coil and the second coil, the in-line type electron Since the color misregistration of the three electron beams due to the positional accuracy of the gun and the like is corrected, it is easy to adjust the convergence of the electron beams more accurately.

According to a fifth aspect of the present invention, there is provided a method of focusing an electron beam.
5. The method for focusing an electron beam according to claim 1, wherein a main magnetic field and a multipole magnetic field orthogonal to a green beam irradiation direction are provided at a position near an electron beam generating side of the in-line type electron gun. At least one or more of each of the sub-magnetic fields having a deflecting magnetic field is formed coaxially with the irradiation direction of the green beam to form a deflecting magnetic field.
Intensity and / or position are changed to deflect at least one of the red, green, and blue beams, and the red, green, and blue beams are opened in a shadow mask opening. Is to be focused.

At least one of a main magnetic field and a sub-magnetic field having a multipolar magnetic field orthogonal to the direction of irradiation of the green beam is provided at a position near the electron beam generating side of the in-line type electron gun. When the deflection magnetic field is formed coaxially with the beam irradiation direction and at least one of the bandwidth, the direction, the intensity, and the position of the deflection magnetic field is appropriately changed, the main magnetic field is reduced to three. Since the color misregistration due to the positional accuracy of the in-line type electron gun that occurs when the electron beams are focused is corrected, the operation of adjusting the focus of the three electron beams more accurately is simplified.

According to a sixth aspect of the present invention, there is provided a method of focusing an electron beam.
In the method of converging an electron beam according to claim 5, the sub-magnetic field is formed by applying a multi-pole permanent magnet, which is formed into a substantially cylindrical shape and whose inner peripheral portion is magnetized to multiple poles along the circumferential direction, in the irradiation direction of the green beam. It is formed at the position where the red beam, the green beam, and the blue beam pass coaxially and passes through the inner peripheral portion, and is disposed on the outer peripheral portion of the neck portion of the color cathode ray tube.

A sub-magnetic field having a multi-pole magnetic field orthogonal to the irradiation direction of the green beam is formed by a substantially cylindrical multi-pole permanent magnet whose inner peripheral portion is magnetized to multi-poles along the circumferential direction. Since the size of the multipole permanent magnet and the magnetic field formed by the multipole permanent magnet are constant, when the multipole permanent magnet is rotated around the axis and moved appropriately along the axial direction, the main magnetic field The color shift due to the positional accuracy of the in-line electron gun, etc., generated when the three electron beams are focused is corrected, so that the more accurate focusing of the three electron beams can be easily adjusted.

According to a seventh aspect of the present invention, there is provided an electron beam focusing apparatus,
Electron beams of three red, green, and blue beams generated from an in-line type electron gun mounted on a neck portion of a color cathode ray tube are focused on an opening of a shadow mask of the color cathode ray tube, and the color cathode ray tube is An electron beam converging device for irradiating the three-color fluorescent film of the screen with the red beam, the green beam, and the blue beam, respectively, wherein the in-line type electron gun has the green color at a position near the electron beam generating side. A main magnetic field is formed by arranging at least one or more of a forward magnetic field having a magnetic field in a beam irradiation direction and a reverse magnetic field having a magnetic field in a direction opposite to the forward magnetic field on the same axis in the green beam irradiation direction. Magnetic field forming means, and changing at least one of a bandwidth, a direction, an intensity, and a position of a main magnetic field of the magnetic field forming means. The red beam, deflecting the green beam, and at least one blue beams, the red beam is a green beam, and a blue beam that includes a focus adjustment means for focusing the opening of the shadow mask.

[0023] At least one of a forward magnetic field having a magnetic field in the direction of irradiation of the green beam generated from the in-line type electron gun and a reverse magnetic field having a magnetic field in the direction opposite to the forward magnetic field is at least one of the directions of irradiation of the green beam. The main magnetic field arranged coaxially is formed by magnetic field forming means, and the focusing, adjusting means appropriately changes at least one of the bandwidth, direction, strength, and position of the main magnetic field to change the electron. When the beams are deflected, the three electron beams are focused on the opening of the shadow mask, so that the focusing of the three electron beams can be easily adjusted, thereby facilitating the manufacture of the apparatus main body.

The electron beam converging device according to claim 8 is
8. The electron beam focusing device according to claim 7, wherein the main magnetic field of the magnetic field forming means is provided on a substantially cylindrical first coil connected to the first power supply unit and coaxially with the first coil. At least one or more of the substantially cylindrical second coils connected to the second power supply unit are positioned coaxially with the irradiation direction of the green beam and at a position where the red, green, and blue beams pass through the inner periphery. In addition, the color cathode-ray tube is formed on the outer periphery of the neck portion of the color cathode-ray tube.

When the main magnetic field of the magnetic forming means is formed by the first coil and the second coil, the current flowing through the first coil and the second coil is appropriately adjusted by the focusing adjusting means. To deflect the electron beam, the three electron beams converge on the opening of the shadow mask.
Focus adjustment of the three electron beams is facilitated, and the three electron beams are focused only by appropriately adjusting the current flowing through the first coil and the second coil, so that the configuration of the apparatus main body is simplified. And the manufacturability is improved.

According to a ninth aspect of the present invention, there is provided an electron beam focusing device,
8. The electron beam converging device according to claim 7, wherein the main magnetic field of the magnetic field forming means includes at least one or more permanent magnets formed in a substantially cylindrical shape and magnetized along the axial direction in the green beam irradiation direction. It is formed at the position where the red beam, the green beam, and the blue beam pass coaxially and passes through the inner peripheral portion, and is disposed on the outer peripheral portion of the neck portion of the color cathode ray tube.

When the main magnetic field of the magnetic field forming means is formed by the permanent magnet magnetized along the axial direction, the size of the permanent magnet and the magnetic field formed by the permanent magnet are constant, so that the focusing is performed. When the adjusting means moves the permanent magnet appropriately in the axial direction to deflect the electron beam, the three electron beams are focused on the opening of the shadow mask.
The focus adjustment operation of the three electron beams is facilitated, and furthermore, the electron beams are focused only by appropriately moving the permanent magnet along the axial direction, so that the configuration of the apparatus body is simplified and the manufacturability is improved. improves.

According to a tenth aspect of the present invention, in the electron beam focusing apparatus according to the seventh aspect, the main magnetic field of the magnetic field forming means is a substantially cylindrical first magnetic field connected to the first power supply unit. And a substantially cylindrical second coil disposed coaxially with the first coil and connected to the second power supply unit, and a permanent coil formed in a substantially cylindrical shape and magnetized along the axial direction. At least one of each of the magnets is coaxial with the irradiation direction of the green beam and the red beam, the green beam, and the blue beam are located at positions passing through the inner peripheral portion, and at the outer peripheral portion of the neck portion of the color cathode-ray tube. It is arranged and formed.

Then, the main magnetic field of the magnetic field forming means is formed by using at least one of the first coil and the second coil, and at least one of the permanent magnets. Then, a permanent magnet is positioned and fixed, and a current of an appropriate value is applied to each of the first coil and the second coil to change the main magnetic field to focus three electron beams. Since the convergence is adjusted substantially by the main magnetic field formed by the permanent magnet, the amount of current supplied to the first coil and the second coil can be reduced. Is simplified, and the manufacture of the apparatus main body becomes easy. When the permanent magnet is appropriately moved along the axial direction to focus the three electron beams, and then a current of an appropriate value is supplied to each of the first coil and the second coil, the in-line type electron Since the color misregistration of the three electron beams due to the positional accuracy of the gun and the like is corrected, more accurate adjustment of the convergence of the electron beams is facilitated, and the configuration is simplified, so that the productivity is improved.

According to an eleventh aspect of the present invention, there is provided the electron beam focusing apparatus according to any one of the seventh to tenth aspects, wherein the in-line type electron gun is provided at a position near the electron beam generating side. A magnetic field, and magnetic field forming means for forming a deflection magnetic field by arranging at least one or more of each of a sub-magnetic field having a multipolar magnetic field orthogonal to the irradiation direction of the green beam on the same axis as the irradiation direction of the green beam; By changing at least one of the bandwidth, direction, intensity, and position of the deflecting magnetic field of the magnetic field forming means to deflect at least one of the red beam, the green beam, and the blue beam, , A green beam and a blue beam to the aperture of the shadow mask.

The magnetic field forming means arranges at least one of a main magnetic field and a sub-magnetic field having a multipolar magnetic field orthogonal to the green beam irradiation direction, at least one coaxially with the green beam irradiation direction. And a deflection magnetic field formed by
If at least one of the bandwidth, the direction, the intensity, and the position of the deflecting magnetic field is appropriately changed by using the convergence adjusting means, the in-line generated when three electron beams are focused by the main magnetic field. The color misregistration due to the positional accuracy of the type electron gun is corrected, so that the electron beam can be focused more accurately, and the electron beam can be more easily focused more easily. The manufacture of the device body becomes easy.

According to a twelfth aspect of the present invention, there is provided an electron beam focusing apparatus according to the eleventh aspect.
The sub-magnetic field of the magnetic field forming means is a multi-pole permanent magnet formed into a substantially cylindrical shape and having an inner peripheral portion magnetized in multiple poles along the circumferential direction. , And a position where the blue beam passes through the inner peripheral portion, and is disposed on the outer peripheral portion of the neck portion of the color cathode ray tube.

The sub-magnetic field of the magnetic field forming means is formed by a substantially cylindrical multipole permanent magnet whose inner peripheral portion is magnetized in multiple poles along the circumferential direction. Since the magnitude and the magnetic field to be formed are constant, the multi-pole permanent magnet is rotated around the axis and moved along the axial direction by appropriately using the focusing adjustment means to deflect the three electron beams.
Since the color shift caused by the positional accuracy of the in-line type electron gun is corrected, more accurate focusing of the electron beam can be easily performed, and the color shift such as the positional accuracy is corrected by using only the multi-pole permanent magnet. Therefore, the configuration of the apparatus main body is simplified, and the manufacture of the apparatus main body becomes easy.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of the electron beam focusing apparatus according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 21 denotes a color CRT.
The color cathode ray tube 21 is used for a monitor display or a television reception, and has a funnel 22 in a body portion. Also, this funnel 22
Is mounted with a screen 24 on which a large number of three-color fluorescent films 23 are regularly formed on the entire surface. When the electron beam 25 is applied to the three-color fluorescent film 23, the three-color fluorescent film 23 becomes red,
A red phosphor 26, a green phosphor 27, and a blue phosphor 28, each of which has a circular shape or a vertically thin rectangular shape that fluoresces green and blue, are regularly arranged. Further, a shadow mask 30 having a large number of openings 29 formed therein is attached inside the screen 24.

A red beam 32, a green beam 33, and a blue beam 34 are provided on the neck 31 of the color cathode ray tube 21.
Three in-line electron guns 35 for generating the three electron beams 25 at equal horizontal intervals are mounted. The three in-line type electron guns 35 are formed so that the red beam 32 and the blue beam 34 are generated from both sides of the position where the green beam 33 is generated. At a position near the side of the in-line type electron gun 35 on which the electron beam 25 is generated, a magnetic field forming means 36 for forming a magnetic field at a position where the red beam 32, the green beam 33, and the blue beam 34 pass.
Is attached. The magnetic field forming means 36 appropriately deflects at least one of the red beam 32, the green beam 33, and the blue beam 34 using the magnetic field forming means 36, and Focus adjustment means 37 for focusing the red beam 32, the green beam 33, and the blue beam 34 is attached to 29.

The magnetic field forming means 36 is provided as shown in FIG.
2 (a) and FIG. 2 (b), a permanent magnet 38 formed into a substantially cylindrical shape and magnetized along the axial direction;
As shown in FIG. 1 and FIG. 25, a multi-pole permanent magnet 40 is formed in a substantially cylindrical shape, and the inner peripheral portion 39 is magnetized to have multiple poles at equal intervals along the circumferential direction. The permanent magnet 38 and the multi-pole permanent magnet 40 are mounted on the same axis as the irradiation direction of the green beam 33 and at a position where the red beam 32, the green beam 33, and the blue beam 34 pass through the inner peripheral portion 39. ing. Also,
The permanent magnet 38 and the multi-pole permanent magnet 40 are arranged near the outer peripheral portion of the neck portion 31 of the color cathode ray tube 21. The permanent magnet 38 is disposed such that the side of the in-line type electron gun 35 that generates the electron beam 25 has an N pole.

Here, the permanent magnet 38 is
The direction from the S pole to the N pole along the axial direction of 38 is defined as the positive direction of the Z axis, and the Z axis of the permanent magnet 38 when the central portion of the permanent magnet 38 in the axial direction on the Z axis is set to 0. The upper portion is magnetized so as to have the magnetic field distribution shown in FIG. 3 and the magnetic field distribution characteristics shown in FIG. Further, this permanent magnet 38
(B) and the intermediate point A on the central axis shown in FIG. _{3, M} 1 m
And the direction of the magnetic field at point A is Z
It is magnetized so as to be in the negative direction of the axis.

Further, the permanent magnet 38 is provided with three electron beams 25 generated from the three in-line type electron guns 35.
But passes through the first part of the S ₁ region of the magnetic field distribution characteristic shown in FIG. 4, are arranged so as to further pass through the S ₂ region of the magnetic field distribution characteristics.

[0040] In this case, the S ₁ region shown in FIG. 4, the green forward field 41 having a magnetic field in the irradiation direction of the beam 33 is formed, at S ₂ area shown in FIG. 4, the reverse of the order of magnetic field 41 A reverse magnetic field 42 having a magnetic field in the direction is formed. Also,
The by S ₁ region and S ₂ regions, the forward field 41 and the reverse magnetic field 42 is the main magnetic field 43 which is disposed coaxially formed.

Further, the multi-pole permanent magnet 40 of the magnetic field forming means 36 is provided at a position near the side of the in-line type electron gun 35 where the electron beam 25 is generated, at a position perpendicular to the irradiation direction of the green beam 33. A sub-magnetic field 44 having the above-described magnetic field is formed.
The multipole permanent magnet 40 includes two quadrupole permanent magnets 45 that are formed in a substantially cylindrical shape and whose inner peripheral portions 39 are magnetized to four poles at equal intervals along the circumferential direction; The two six-pole permanent magnets 46 are formed into a substantially cylindrical shape having substantially the same shape as above, and the inner peripheral portion 39 is magnetized into six poles at equal intervals along the circumferential direction. It is arranged and formed. This 2
The four-pole permanent magnets 45 are arranged so as to cancel the sub-magnetic field 44 formed by the four-pole permanent magnets 45 in advance.
Similarly, the two six-pole permanent magnets 46 are also arranged so that the sub-magnetic fields 44 formed by the six-pole permanent magnets 46 cancel each other in advance. Further, the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46 are arranged such that when one of them is relatively rotated about the axis, a sub-magnetic field 44 is formed. I have.

Then, the main magnetic field 43 and the sub-magnetic field 44 are coaxially positioned by the permanent magnet 38 and the multipole permanent magnet 40 at a position near the side of the in-line type electron gun 35 where the electron beam 25 is generated. An arranged deflection magnetic field 47 is formed.

Next, the convergence adjusting means 37 is connected to the permanent magnet 38 and the multi-pole permanent magnet 40 of the magnetic field forming means 36. The convergence adjusting unit 37 is a unit for positioning the permanent magnet 38 and the multi-pole permanent magnet 40 by appropriately moving the permanent magnet 38 and the multi-pole permanent magnet 40 by an operator.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, as shown in FIG. 5, three in-line type electron guns 35 generate three electron beams 25, a red beam 32, a green beam 33, and a blue beam 34.

Then, the three electron beams 25 are turned into permanent magnets 38.
When passing through a part of the S ₁ region shown in FIG. 4, the forward magnetic field 41 from the permanent magnet 38 acts on the three electron beams 25, red beam 32 and the blue beam 34, according to Fleming's left-hand rule, The light is deflected toward the central axis of the permanent magnet 38 while rotating clockwise around the green beam 33 in the irradiation direction of the green beam 33. Further, since the three electron beams 25 when it passes through the S ₂ region of FIG. 4 of the permanent magnet 38, opposite magnetic field 42 acts by the permanent magnet 38 to the three electron beams 25, red beam 32 and the blue beam 34 is deflected toward the central axis of the permanent magnet 38 while rotating counterclockwise around the green beam 33 in the direction of irradiation of the green beam 33 according to Fleming's left-hand rule. Here, the red beam 32 and the blue beam 34
It is returned to the horizontal state by the deflection of the direction of rotation of the two according to some and S ₂ regions of S ₁ region. In addition, since the green beam 33 passes on the central axis of the permanent magnet 38 and is not affected by the main magnetic field 43 of the permanent magnet 38, it is not deflected.

[0047] Further, as shown in FIG. 4, the magnetic flux density of the S ₁ region is larger than the magnetic flux density of the S ₂ regions, the red beam 32 and the blue beam 34 deflected by the permanent magnet 38 is , As shown in FIG.

Here, the magnetic field formed by the permanent magnet 38 is constant, and the electron beam 25 is
Since the deflection sensitivity decreases as the electron beam 25 is generated, the convergence adjusting means 37 appropriately moves the permanent magnet 38 of the magnetic field forming means 36 along the axial direction. Is the shadow mask of the color CRT 21
30 and the red phosphor 26, the green phosphor 27, and the blue phosphor 28 of the three-color phosphor film 23 of the screen 24.
A red beam 32, a green beam 33, and a blue beam 34 irradiate, respectively.

The size of the permanent magnet 38 is constant,
As shown in FIG. 4, the permanent magnet 38, the magnetic flux density M ₁ is changed, the magnetic flux density M ₂ is changed with a change in magnetic flux density M _1, the optimum magnetic flux density M for the color CRT 21 to be mounted _{When the} permanent magnet 38 is magnetized so as to have the value ₁ , the mounting position of the permanent magnet 38 is determined.

Next, referring to FIGS. 6 to 11, a method of correcting a color shift caused when the three electron beams 25 are focused by appropriately adjusting the main magnetic field 43 by using the sub-magnetic field 44 will be described with reference to FIGS. explain.

The color shift of the convergence of the three electron beams 25 is caused by the positional accuracy of the in-line type electron gun 35 of the color CRT 21 and the like.

First, a correction method in the case where three electron beams 25 are arranged horizontally, but the red beam 32 and the blue beam 34 are shifted from the expected convergence position of the green beam 33 with reference to FIG. explain.

In order to correct the color shift of the convergence of the electron beam 25 shown in FIG. 6, two six-pole permanent magnets shown in FIG.
Use 46. Then, the two six-pole permanent magnets 46 are appropriately rotated about their axes by the convergence adjusting means 37 to form an appropriate auxiliary magnetic field 44, and the two six-pole permanent magnets 46 are formed.
Is appropriately moved in the axial direction to correct the point P shown in FIG. 6 by superimposing it on the point O shown in FIG.

Next, as shown in FIG. 7, the three electron beams 25 are arranged vertically, but the red beam 32 and the blue beam 34 are horizontally displaced from the expected convergence position of the green beam 33. The correction method will be described.

In order to correct the deviation of the convergence of the electron beam 25 shown in FIG. 7, two six-pole permanent magnets 46 shown in FIG.
Is used. Then, the convergence adjusting means 37 appropriately rotates the two six-pole permanent magnets 46 around the respective axes, thereby obtaining an appropriate auxiliary magnetic field.
44 to form a, suitably moved in the axial direction P ₁ point shown in Figure 7. The two 6-pole permanent magnet 46, it is corrected to overlap the O ₁ point shown in FIG. Here, the color shift of the focusing of the electron beam shown in FIGS.
It is corrected only by

Further, as shown in FIG. 8, the three electron beams 25 are arranged at equal horizontal intervals, but the red beam 32 and the blue beam 34 are symmetrically separated from the position where the green beam 33 is to be focused. A description will be given of a correction method when the state, that is, the focus position of the three electron beams 25 is shifted to the outside of the opening 29 of the shadow mask 30 of the color cathode ray tube 21.

8 can be corrected by increasing the magnetic force of the permanent magnet 38 shown in FIGS. 2 to 5, the two-pole permanent magnet shown in FIG. 1 can be corrected. The correction can also be made by using the sub-magnetic field 44 formed by the magnet 45. Then, the convergence adjusting means 37 appropriately rotates each of the two four-pole permanent magnets 45 around the axis to form an appropriate sub-magnetic field 44, and appropriately adjusts the two four-pole permanent magnets 45 in the axial direction. move the O ₃ points shown in FIG. 8, is corrected to overlap the O ₂ points shown in FIG. 8.

As described above, in the above embodiment,
At a position near the side of the in-line type electron gun 35 that generates the electron beam 25, a permanent magnet 38 formed into a substantially cylindrical shape and magnetized along the axial direction is coaxial with the irradiation direction of the green beam 33, and Since the permanent magnet 38 is disposed near the outer peripheral portion of the neck portion 31 of the color cathode ray tube 21, the green beam
Forward magnetic field 41 having a magnetic field of 33 irradiation directions, and forward magnetic field 41
A main magnetic field 43 is formed in which a reverse magnetic field 42 having a magnetic field in the opposite direction is arranged coaxially. Since the convergence adjusting means 37 is connected to the permanent magnet 38, the convergence adjusting means 37 simply moves the permanent magnet 38 appropriately in the axial direction, and the red beam 32, the green beam 33, and Since the three electron beams 25 of the blue beam 34 can be focused on the opening 29 of the shadow mask 30, the focusing of the three electron beams 25 can be easily adjusted. Further, if one permanent magnet 38 is appropriately adjusted, 3
Since the electron beam 25 is focused, the number of parts of the apparatus main body is reduced, and the manufacturing cost can be reduced.

The electron beam of the in-line type electron gun 35
In the vicinity of the side generating 25, and near the outer periphery of the neck portion of the color cathode-ray tube, a substantially cylindrical shape was formed, and the inner periphery 39 was magnetized to four poles at equal intervals along the circumferential direction. A 4-pole permanent magnet 45, and a 6-pole permanent magnet formed into a substantially cylindrical shape and having an inner peripheral portion 39 magnetized to 6 poles at equal intervals along the circumferential direction.
The two 46-pole permanent magnets 45 and the two 6-pole permanent magnets 46 are arranged in the irradiation direction of the green beam 33 because the two 46 are arranged coaxially in the irradiation direction of the green beam 33. A sub-magnetic field 44 having orthogonal multi-pole magnetic fields is formed.
Since the convergence adjusting means 37 is connected to the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46, the convergence adjusting means 37 controls the two four-pole permanent magnets 45 and the two six-pole permanent magnets. The pole permanent magnet 46 is appropriately rotated around the axis to form the sub-magnetic field 44, and the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46 are appropriately moved along the axial direction. Since the color shift of the electron beam 25 caused by the positional accuracy of the in-line electron gun 35 can be corrected, the two four-pole permanent magnets 45 and the two six-pole permanent magnets when the color shift of the electron beam 25 is corrected. If 46 is positioned and fixed, in-line electron gun 35
The displacement of the electron beam caused by the positional accuracy of the electron beam is always corrected.

The sub-magnetic field 44 formed by the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46 is formed so as to enclose the three electron beams 25, so that the main magnetic field
The three electron beams 25 generated by the positional accuracy of the in-line electron gun 35 without deteriorating the focus characteristics due to 43
Can be easily corrected by the sub-magnetic field 44.

Further, the sub-magnetic field 44 formed by the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46 corrects the color shift of the electron beam caused by the positional accuracy of the in-line electron gun 35 and the like. However, since the three electron beams 25 are almost converged by the deflection by the main magnetic field 43 formed by the permanent magnet 38, the correction amount by the sub-magnetic field 44 is small, so that two four-pole permanent magnets are used. Correction by the 45 and two six-pole permanent magnets 46 can be easily performed.

The neck portion 31 of the color CRT 21
9 focuses the red beam 32, the green beam 33, and the blue beam 34 generated from the in-line type electron gun 35 mounted on the opening 29 of the shadow mask 30 in the irradiation direction of the green beam 33. And a magnetic field in a direction along the irradiation direction of the green beam 33 is not used.
Therefore, when a magnetic field in the direction along the irradiation direction of the green beam 33 is formed at the passage position of the three electron beams 25 from the outside, the amount of change in the magnetic field in the direction along the irradiation direction of the green beam 33 is: Since it changes from 0 to the strength of the magnetic field formed from the outside, the rate of change is M = M = the magnetic field strength for focusing the electron beam 25 and m = the external magnetic field strength. Since it is 0, the rate of change = m / (M + m) = m / m = 1.

However, in the method of converging an electron beam according to the above-described embodiment, the main magnetic field 43 in the direction along the irradiation direction of the green beam 33 is mainly used. And a magnetic field of intensity M is formed with respect to the passing position of the blue beam 34, and a magnetic field of intensity m further from the outside in a direction along the irradiation direction of the green beam 33, the red beam 32, green beam 33, And at the passage position of the blue beam 34, the rate of change of the magnetic field in the direction along the irradiation direction of the green beam 33 is as follows: rate of change = m / (M + m) <1.

Therefore, the main magnetic field 43 having a magnetic field in the direction along the irradiation direction of the green beam 33 causes the red beam 32, the green beam 33,
When the blue beam 34 is focused, the influence of the external magnetic field m in the direction along the irradiation direction of the green beam 33 is small. That is, the external magnetic field m is a magnetic field due to terrestrial magnetism, and is about 0.03 mT. In addition, the main magnetic field 43M is set to 0.
Since the value is set to a large value of about 5 mT, the rate of change is small, and color shift due to terrestrial magnetism generated when three electron beams 25 are focused can be greatly reduced.

For this reason, the electron beam focusing device shown in FIG. 9 has two four-pole permanent magnets 45 and two six-pole permanent magnets.
A strip-shaped terrestrial magnetism shield plate 48 is attached to the radially symmetric position of the inner peripheral portion 39 of 46 to correct the color shift caused by terrestrial magnetism that occurs when three electron beams 25 are focused. Since the shield plate 48 is made of a material having high magnetic permeability, the magnetism of the four-pole permanent magnet 45 and the six-pole permanent magnet 46 flows into the shield plate 48. For this reason, the adjustment for converging the three electron beams 25 while compensating the color misregistration due to the terrestrial magnetism by the terrestrial magnetism shield plate 48 is complicated.

However, the electron beam focusing apparatus according to the above embodiment focuses the three electron beams 25 using the main magnetic field 43 along the irradiation direction of the green beam 33.
Since the influence of the geomagnetism is small, the geomagnetic shield plate 48 becomes unnecessary. Therefore, since the number of parts of the apparatus main body can be reduced, manufacturability can be improved.

Then, the permanent magnet 38, two 4-pole permanent magnets
45, and three red beams 32 and three green beams 3 generated from an in-line type electron gun 35 using two six-pole permanent magnets 46.
3, and the blue beam 34 is focused on the opening 29 of the shadow mask 30. Therefore, compared to the focusing state in the electron beam focusing method shown in FIG. Since the number is small, the three electron beams 25 can be accurately and easily focused.

The main magnetic field 43 formed by the permanent magnet 38
A forward magnetic field 41 having a magnetic field in the irradiation direction of the green beam 33, and a reverse magnetic field 42 having a magnetic field in the opposite direction of the forward magnetic field 41 are disposed coaxially in the irradiation direction of the green beam 33, and This is a magnetic field along the irradiation direction. A deflection yoke (not shown) is attached to the outer periphery of the neck portion 31 of the color cathode-ray tube 21. The deflection yoke forms a multipolar magnetic field orthogonal to the irradiation direction of the green beam 33. ing. Therefore, since the direction of the main magnetic field 43 formed by the permanent magnet 38 and the direction of the magnetic field formed by the deflection yoke are orthogonal, the magnetic field between the permanent magnet 38 that focuses the three electron beams 25 and the deflection yoke Interference can be reduced.

The magnetic field forming means 36 includes permanent magnets 38, 2
It has four four-pole permanent magnets 45 and two six-pole permanent magnets 46. When the three electron beams 25 are focused by the main magnetic field 43 formed by the permanent magnets 38, the color cathode ray tube 21 If the color misregistration caused by the positional accuracy of the in-line type electron gun 35 does not occur, the two 4-pole permanent magnets
A sub-magnetic field 44 formed by 45 and two six-pole permanent magnets 46
It is not necessary to perform correction by
The pole permanent magnet 45 and the two six-pole permanent magnets 46 need not be provided.

Although the permanent magnet 38, the 4-pole permanent magnet 45, and the 6-pole permanent magnet 46 of the magnetic field forming means 36 are formed separately from each other, they may be formed integrally.
For example, instead of permanent magnet 38 and quadrupole permanent magnet 45,
Permanent magnet formed into a substantially cylindrical shape and magnetized along the axial direction
The inner circumference of 38 was magnetized to 4 poles at equal intervals along the circumferential direction.
Even with the use of the pole multiplex permanent magnet 71, the same effect as in the case of a separate body can be obtained.

Next, another embodiment of the electron beam focusing apparatus according to the present invention will be described with reference to FIGS.

In the embodiment shown in FIGS. 10 and 11, the permanent magnet 38 of the magnetic field forming means 36 in the embodiment shown in FIGS. 1 to 8 is replaced with a permanent magnet 38 and a second permanent magnet 49. Is the case.

As shown in FIG. 10, the second permanent magnet 49 is formed into a substantially cylindrical shape having substantially the same shape as the permanent magnet 38, and is magnetized along the axial direction. The permanent magnet
38 and the second permanent magnet 49 are coaxial and
They are arranged with the same poles facing each other. The permanent magnet 38 is disposed such that the side of the in-line type electron gun 35 that generates the electron beam 25 is an N pole.

Here, the permanent magnet 38 and the second permanent magnet 49 are directed toward the in-line type electron gun 35 along the axial direction from the center of the central axis of the permanent magnet 38 and the second permanent magnet 49. The direction is the positive direction of the Z axis,
The magnetic field distribution shown in FIG. 10 and the magnetic field shown in FIG. 11 are plotted on the Z axis of the permanent magnet 38 and the second permanent magnet 49 when the center on the Z axis of the second permanent magnet 49 is set to 0. It is magnetized to have distribution characteristics.

[0075] Further, the permanent magnet 38 and the second permanent magnets 49, three electron beams 25 generated from the in-line type electron gun 35 of the three are first S ₃ region of magnetic field distribution characteristic shown in FIG. 11 passes through, are arranged so as to further pass through the S ₄ region of the magnetic field distribution characteristics.

[0076] In this case, the _{S 3} region shown in FIG. 11, the forward magnetic field 41 is formed, in _{S 4} region shown in FIG. 11,
A reverse magnetic field 42 is formed. Further, the main magnetic field 43 is formed in the S ₃ region and S ₄ region.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, as shown in FIG. 10, three in-line type electron guns 35 generate three electron beams 25, a red beam 32, a green beam 33, and a blue beam 34.

Then, the three electron beams 25 are turned into the permanent magnets 38.
And it passes through the S ₃ region shown in FIG. 11 of the second permanent magnet 49, because the forward magnetic field 41 acting on the three electron beams 25, red beam 32 and the blue beam 34, electrons around the green beam 33 The beam is deflected toward the central axis of the permanent magnet 38 while rotating clockwise in the irradiation direction of the beam 25. Also, 3
When the electron beam 25 passes through the S ₄ region shown in FIG. 11, since the opposing magnetic field 42 acts on the three electron beams 25, red beam 32 and the blue beam 34, electrons around the green beam 33 The beam is deflected toward the central axis of the second permanent magnet 49 while rotating counterclockwise in the direction of irradiation of the beam 25.

The red beam 32 and the blue beam 34
It is returned to the horizontal state by the deflection of the two rotational directions by the _three areas and S ₄ region. Furthermore, the green beam 33
Since it passes on the central axis of the permanent magnet 38 and the second permanent magnet 49, it is not deflected because it is not affected by the main magnetic field 43.

[0081] Further, as shown in FIG. 11, the S ₃ regions flux density M ₃ of the larger form than S ₄ regions flux density M ₄ of the electron beam 25, the electron beam 25 in-line type electron gun 35 Since the deflection sensitivity decreases as the position approaches the side where the wobble is generated, this permanent magnet 38 and the second permanent magnet 49
The red beam 32 and the blue beam 34 deflected by the green beam 33
Focus on Then, using the focusing adjustment means 37, the permanent magnet
When the 38 and the second permanent magnet 49 are appropriately moved along the axial direction, the three electron beams 25 converge on the opening 29 of the shadow mask 30 and irradiate the three-color fluorescent film 23 of the screen 24. .

The permanent magnet 38 and the second permanent magnet 49
Since the size of each of them is constant, as shown in FIG. 11, the color cathode ray tube 21 to which the magnetic flux density M ₃ of the permanent magnet 38 and the magnetic flux density M ₄ of the second permanent magnet 49 are attached.
By adjusting the permanent magnet 38 and the second permanent magnet 49 to an optimum value, the mounting positions of the permanent magnet 38 and the second permanent magnet 49 are determined.

As described above, the two permanent magnets, separate from the permanent magnet 38 and the second permanent magnet 49, use the forward magnetic field of the main magnetic field 43.
Since the permanent magnet 41 and the reverse magnetic field 42 are formed, the permanent magnet 38 and the second permanent magnet 49 having different magnetic flux densities can be appropriately combined, so that the applicable range of magnets that can be used is widened. Further, since the three electron beams 25 are focused on the opening 29 of the shadow mask 30 only by appropriately moving the permanent magnet 38 and the second permanent magnet 49 along the axial direction,
The focusing of the electron beam 25 can be easily adjusted.

Also, using the permanent magnet 38 and the second permanent magnet 49, the red beam 32, the green beam 33, and the blue beam 34 are focused by the convergence adjusting means 37 and the opening of the shadow mask 30 of the color CRT 21. Since the beam can be focused to the position 29, the same operation and effect as those of the electron beam focusing device shown in FIGS. 1 to 8 can be obtained.

Next, still another embodiment of the electron beam focusing apparatus according to the present invention will be described with reference to FIGS.

The embodiment shown in FIGS. 12 and 13 corresponds to the magnetic field forming means 36 of the embodiment shown in FIGS.
Is replaced with a first coil 50 and a second coil 51.

As shown in FIG. 12, the first coil 50 is formed in a substantially cylindrical shape, and is connected to a first power supply 52 for supplying a current to the first coil 50. Also,
The second coil 51 is formed in a substantially cylindrical shape having substantially the same shape as the first coil 50, and is connected to a second power supply unit 53 that supplies a current to the second coil 51. The first coil 50 and the second coil 51 are formed by winding a copper wire or the like along the circumferential direction. And the second coil
Reference numeral 51 is provided coaxially with the first coil 50.
Further, the first power supply unit 52 and the second power supply unit 53
It is provided in the convergence adjusting means 37 shown in FIG.

The first coil 50 and the second coil 51 are connected to the electron beam of the in-line type electron gun 35.
The green beam 33 is located on the same side as the emission direction of the green beam 33. Further, the first coil 50 and the second coil 51 are disposed near the outer peripheral portion of the neck portion 31 of the color cathode ray tube 21.

Here, a current is supplied to the first coil 50 from the first power supply section 52 in a forward direction, for example, a clockwise direction in the direction of irradiation of the green beam 33, and the second coil 51 , A counterclockwise current is supplied from the second power supply unit 53 in the opposite direction, for example, in the irradiation direction of the green beam 33. When the current is supplied, the first coil 50 and the second coil 51 are separated from the second coil 51 by the first coil 50 and the second coil 51.
The first coil 50 and the second coil 51 when the axial direction toward the first coil 50 is defined as the positive direction of the Z axis, and the intermediate portion between the first coil 50 and the second coil 51 is defined as 0. An electromagnetic field is formed on the central axis so as to have the magnetic field distribution shown in FIG. 12 and the magnetic field distribution characteristics shown in FIG.

Further, the first coil 50 and the second coil 51 are arranged so that the three electron beams 25 generated from the three in-line electron guns 35 have the magnetic field distribution characteristics shown in FIG. passes through the S ₅ regions are arranged so as to further pass through the S ₆ region of the magnetic field distribution characteristics.

[0091] In this case, the _{S 5} region shown in FIG. 13, the forward magnetic field 41 is formed, at _{S 6} region shown in FIG. 12,
A reverse magnetic field 42 is formed. Further, the main magnetic field 43 is formed by the S ₅ regions and S ₆ region.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, as shown in FIG. 12, three in-line type electron guns 35 generate three electron beams 25 of a red beam 32, a green beam 33, and a blue beam.

[0094] Then, when passing through the electron beam 25 in three of the S ₅ region shown in FIG. 13, because the forward magnetic field 41 acting on the three electron beams 25 by the electromagnetic force of the first coil 50, the red beam
32 and the blue beam 34 are deflected toward the central axis of the first coil 50 while rotating clockwise around the green beam 33 in the direction of irradiation of the electron beam 25. FIG.
The S ₆ region shown in 3 when three electron beams 25 to pass through, since the reverse magnetic field 42 due to the electromagnetic force of the second coil 51 acts on the three electron beams 25, red beam 32 and the blue beam 34
Is deflected toward the central axis of the second coil 51 while rotating counterclockwise around the green beam 33 in the direction of irradiation of the electron beam 25.

The red beam 32 and the blue beam 34
It is returned to the horizontal state by the deflection of the two rotational directions by ₅ regions and S ₆ region. Furthermore, the green beam 33
Since it passes on the central axis of the first coil 50 and the second coil 51, it is not affected by the main magnetic field 43 and is not deflected.

Further, the magnetic flux density M _{5 in the} S ₅ region is
Because it is formed by the electromagnetic force of the coil 50, thereby adjusting the supply current of the first power source unit 52 appropriately in the focusing adjusting means 37, the magnetic flux density M ₆ of S ₆ region, the second coil
Since it is formed by the electromagnetic force of 51, the focusing adjustment means 37
When the supply current value of the second power supply unit 53 is appropriately adjusted,
The electron beam 25 is focused on the opening 29 of the shadow mask 30 and is irradiated on the three-color fluorescent film 23 of the screen 24.

As described above, if the supply current flowing through the first coil 50 and the second coil 51 is appropriately adjusted, FIG.
The value of the magnetic flux density M ₆ of the magnetic flux density M ₅ and an opposing magnetic field 42 of the forward field 41 shown in 3 changes freely. Therefore, the first coil
By appropriately adjusting the value of the current supplied to each of the first coil 50 and the second coil 51, the focusing positions of the red beam 32, the green beam 33, and the blue beam 34 can be moved.
Even if the second coil 51 is used, the three electron beams 25 can be easily focused on the opening 29 of the shadow mask 30.

Next, the electron beam focusing device shown in FIG. 14 includes a deflection coil 54 for focusing three electron beams 25. The deflection coil 54 is coaxially attached to the outer periphery of the neck portion 31 of the color cathode-ray tube 21 and the electron beam 25 of the in-line type electron gun 35.
And a position near the deflection yoke (not shown) and the in-line type electron gun 35. Further, the deflection coil 54 has an inner peripheral portion of a core 55 which is formed of a material having high magnetic permeability in a substantially cylindrical shape.
4-pole V correction coil 57 to 56, 4-pole H correction coil 58, 6-pole V
A correction coil 59 and a six-pole H correction coil 60 are mounted. The four-pole V correction coil 57, the four-pole H correction coil 58, the six-pole V correction coil 59, and the six-pole H correction coil 60 have a 4V power supply unit (not shown) for supplying an appropriate current to each coil. , 4H power unit, 6V power unit, and 6H power unit are connected to each other.

Then, a 4V power supply section of the deflection coil 54,
When currents of appropriate values are supplied to the 4H power supply unit, the 6V power supply unit, and the 6H power supply unit, three electron beams 25 generated from the in-line type electron gun 35 are focused. The deflection coil 54 includes a 4-pole V correction coil 57, a 4-pole H correction coil 58,
It is composed of a total of 20 coils of a 6-pole V correction coil 59 and a 6-pole H correction coil 60, and a total of 4 power supply units of a 4V power supply unit, a 4H power supply unit, a 6V power supply unit, and a 6H power supply unit. Therefore, adjustment when focusing the three electron beams 25 is complicated.

However, in the electron beam focusing apparatus shown in FIGS. 12 and 13, the first power supply section 52 connected to the first coil 50 and the second power supply section connected to the second coil 51 are provided. By properly controlling 53, three electron beams 25
Are focused, and the configuration is simpler than that of the electron beam focusing apparatus shown in FIG. 14, so that the manufacturing cost can be reduced and the manufacturability can be improved.

When the current value flowing through the first coil 50 and the current value flowing through the second coil 51 are appropriately adjusted by the convergence adjusting means 37, the red beam 32, the green beam 33, and the blue beam Since the light is focused on the opening 29 of the shadow mask 30 of the color cathode ray tube 21, the same operation and effect as those of the embodiment shown in FIGS. 1 to 8 can be obtained.

Next, still another embodiment of the electron beam focusing apparatus of the present invention will be described with reference to FIG.

The embodiment shown in FIG. 15 is different from the embodiment shown in FIGS. 1 to 8 in that the first coil of the magnetic field forming means 36 in the embodiment shown in FIGS. There is provided a magnetic field forming means 36 in which the 50 and the second coil 51 are combined.

As shown in FIG. 15, the permanent magnet 38 is located near the outer peripheral portion of the first coil 50 and is disposed coaxially with the first coil 50. The main magnetic field 43 is formed on the inner periphery of the permanent magnet 38 as shown in FIGS.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, as shown in FIG. 15, three electron beams 25 of a red beam 32, a green beam 33, and a blue beam 34 are generated from three in-line type electron guns 35.

Then, when the three electron beams 25 pass through the inner peripheral portion of the permanent magnet 38, the forward magnetic field 41 and the reverse magnetic field 42 of the main magnetic field 43 act, so that the red beam 32 and the blue beam 34 While turning clockwise around the irradiation direction of the electron beam 25 around 33, the electron beam 25 is deflected toward the center axis of the first coil 50. Further, the red beam 32 and the blue beam 34
The light is deflected toward the central axis of the second coil 51 while rotating counterclockwise around the irradiation direction of the electron beam 25 about the green beam 33.

At the same time, a current of an appropriate value is applied to the first coil 50 and the second coil 51 by using the convergence adjusting means 37, and the three electron beams 25 are applied to the opening of the shadow mask 30 of the color CRT 21. Focus on 29.

As described above, when a current of an appropriate value is applied to the first coil 50 and the second coil 51, the forward magnetic field 41 and the reverse magnetic field 42 of the permanent magnet 38 change. If the supply current values of the first power supply unit 52 and the second power supply unit 53 are appropriately adjusted using this method, the focus positions of the red beam 32, the green beam 33, and the blue beam 34 can be adjusted without moving the permanent magnet 38. The three electron beams 25 can be easily focused on the openings 29 of the shadow mask 30 of the color CRT 21 because they can move.

The main magnetic field formed by the permanent magnet 38
43 is changed by the electromagnetic force of the first coil 50 and the second coil 51 so that the three electron beams 25
The current value supplied to the first coil 50 and the second coil 51 can be small because the light is focused on the opening 29 of the first coil 50.

The first coil 50 and the second coil
When a current of an appropriate value is passed through 51, three electron beams 25 are focused on the opening 29 of the shadow mask 30, so that the same operation and effect as in the embodiment shown in FIGS. 12 and 13 can be obtained. it can.

Next, still another embodiment of the electron beam focusing apparatus of the present invention will be described with reference to FIG.

The embodiment shown in FIG. 16 is different from the embodiment shown in FIGS. 10 and 11 in that the inner peripheral portions of the permanent magnet 38 and the second permanent magnet 49 of the magnetic forming means 36 are provided with the first and second permanent magnets.
The magnetic field forming means 36 is provided with the coil 50 and the second coil 51 arranged coaxially.

The main magnetic field 43 is formed on the inner peripheral portions of the permanent magnet 38 and the second permanent magnet 49 as shown in FIGS.

Next, the operation of the above embodiment will be described with reference to the drawings.

First, as shown in FIG. 16, three electron beams 25 of a red beam 32, a green beam 33, and a blue beam 34 are generated from three in-line type electron guns 35.

Then, the permanent magnet 38 and the second permanent magnet
When three electron beams 25 pass through the inner periphery of 49, the main magnetic field
Since the forward magnetic field 41 and the reverse magnetic field 42 of 43 act, the red beam 32 and the blue beam 34
It is deflected toward the central axis of the first coil 50 while rotating clockwise in the 25 irradiation direction,
32 and the blue beam 34 are deflected toward the center axis of the second coil 51 while rotating counterclockwise around the green beam 33 in the direction of irradiation of the electron beam 25.

At the same time, by using the convergence adjusting means 37, currents of appropriate values are passed from the first power supply unit 52 and the second power supply unit 53 to the first coil 50 and the second coil 51, and the three coils are adjusted. The electron beam 25 is focused on the opening 29 of the shadow mask 30 of the color CRT 21.

As described above, when a current of an appropriate value is applied to the first coil 50 and the second coil 51, the forward magnetic field 41 and the reverse magnetic field 42 by the permanent magnet 38 and the second permanent magnet 49 change. Therefore, the first power supply 52
If the supply current value of the second power supply unit 53 is appropriately adjusted, the focus positions of the red beam 32, the green beam 33, and the blue beam 34 move without moving the permanent magnet 38 and the second permanent magnet 49. Because it is possible, shadow mask of color CRT 21
The three electron beams 25 can be easily focused on the 30 openings 29. Therefore, the same operation and effect as those of the embodiment shown in FIG. 15 can be obtained.

Next, still another embodiment of the electron beam focusing apparatus of the present invention will be described with reference to FIG.

In the embodiment shown in FIG. 17, two quadrupole permanent magnets 45 superposed coaxially and coaxially on both ends in the axial direction of a spacer 65 formed in a substantially cylindrical shape. The two superposed six-pole permanent magnets 46 are mounted coaxially. The permanent magnet 38 and the second permanent magnet 49 are coaxially disposed on both axial ends of the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46, respectively. . Furthermore, this permanent magnet 38
The first coil 50 and the second coil 51 are coaxially disposed on the inner peripheral portion 39 of the second permanent magnet 49.

Then, a current is supplied to the first coil 50 from the first power supply unit 52 in a forward direction, for example, a clockwise current in the direction of irradiation of the green beam 33, and to the second coil 51. A counterclockwise current is supplied from the second power supply unit 53 in the opposite direction, for example, in the irradiation direction of the green beam 33. Then, the forward magnetic field 41 is formed on the inner periphery of the first coil 50 by the electromagnetic force of the first coil 50.
Further, the reverse magnetic field 42 is formed on the inner peripheral portion of the second coil 51 by the electromagnetic force of the second coil 51. Further, the main magnetic field 43 is formed by the forward magnetic field 41 and the reverse magnetic field.

The permanent magnet 38 and the second permanent magnet 49 are respectively magnetized in the axial direction, and the same poles are opposed to each other and arranged coaxially. The main magnetic field 43 as shown in FIGS. 10 and 11 is formed only by 38 and the second permanent magnet 49.

Here, the first coil 50 of the magnetic field forming means 36
When the current value supplied to the second coil 51 is appropriately adjusted, the three electron beams 25 are focused on the opening 29 of the shadow mask 30 of the color CRT 21. Also, two 4-pole permanent magnets 45 and two 6-pole permanent magnets 46
Is appropriately rotated relatively around the axis to form an appropriate sub-magnetic field 44, thereby correcting the color shift caused by the positional accuracy of the in-line type electron gun 35 and the like.

As described above, the values of the currents supplied to the first coil 50 and the second coil 51 are appropriately adjusted, and the two four-pole permanent magnets 45 and the two six-pole permanent magnets 46 are used.
When the sub-magnetic field 44 is formed by rotating the sub-field 44 appropriately about the axial center, the three electron beams 25 are used to correct the color shift caused by the positional accuracy of the in-line type electron gun 35 and the like. Since focusing is performed by the unit 29, more accurate focusing adjustment of the electron beam can be easily performed, so that the same operation and effect as the embodiment shown in FIG. 16 can be obtained.

[0126]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for focusing an electron beam according to the present invention will be described below with reference to FIGS.

The magnetic field forming means 36 shown in FIGS.
As shown in FIGS. 18A and 18B, the permanent magnet 38 is formed into a cylindrical shape having an inner diameter of 33.5 mm, an outer diameter of 36.5 mm, and a height of 10 mm. The permanent magnet 38 has a magnetic field distribution shown in FIG. 19, and as shown in FIG.
It is magnetized along the axial direction so as to be 42 mT.

The three permanent magnets 38 are coaxially arranged in the direction of irradiation of the green beam 33 generated from the in-line type electron gun 35 mounted on the neck 31 of the 15-inch type color cathode ray tube 21. The color CRT 21 is mounted near the outer periphery of the neck portion 31 at the position where the beam 25 passes through the inner periphery.

Next, the color cathode ray tube 21 is operated to generate a cross hatch signal by the pattern generator 66 connected to the rear end of the neck portion 31 of the color cathode ray tube 21, and is connected to the pattern generator 66. A cross hatch signal is input from the CRT driving circuit 72 to the color CRT 21. Then, the color CRT
The 21 screen 24 has a red cross hatch pattern 6 by a red beam 32, a green beam 33, and a blue beam 34, respectively.
8, a state where the green cross hatch pattern 69 and the blue cross hatch pattern 70 are separated is displayed.

Then, the mounting position is adjusted by appropriately moving the permanent magnet 38 along the axial direction. Then, the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 overlap, and a white cross hatch pattern is displayed on the screen 24 of the color CRT 21.

As described above, in this embodiment, when the permanent magnet 38 is appropriately moved along the axial direction, the red beam 32,
The green beam 33 and the blue beam 34 are focused on the opening 29 of the shadow mask 30 of the color CRT 21 and irradiate the three-color fluorescent film 23 on the screen 24 of the color CRT 21, and the cross hatch generated by the pattern generator 66 Since the signal is output to the screen 24, the three electron beams 25 can be easily focused only by adjusting the movement of the permanent magnet 38 along the axial direction.

Next, the permanent magnet 38 is mounted on the 29-inch color CRT 21. Then, as in the case where the color cathode ray tube 21 of the 15-inch type is mounted, 3
Focusing of the electron beam 25 is performed. Then, the cross hatch signal generated by the pattern generator 66 is output to the screen 24 of the color CRT 21 as a white cross hatch pattern, similarly to the case where the color CRT 21 is mounted on the 15-inch color CRT 21. Therefore, the focusing of the electron beam 25 can be easily adjusted.

Next, the permanent magnet shown in FIGS.
The color cathode-ray tube 21 on which 38 is mounted is rotated in the horizontal direction, and a shift generated when the electron beam 25 with respect to terrestrial magnetism is focused is measured.

First, a 15-inch type color cathode ray tube 21
The two 4 coaxially arranged 4
A pole permanent magnet 45 and two 6-pole permanent magnets 46 disposed coaxially are mounted coaxially. Here, a 15-inch type color CRT 21 to which the geomagnetic shield plate 48 is not attached is used.

Then, three electron beams 25 are generated from the in-line type electron gun 35 mounted on the neck portion 31 of the color cathode ray tube 21. Then, the two quadrupole permanent magnets 45 and the two six-pole permanent magnets 46 are appropriately rotated relatively about the axis to form an appropriate sub-magnetic field 44, and the two quadrupole permanent magnets 45 are formed. Then, the three six-pole permanent magnets 46 are appropriately moved along the axial direction to focus the three electron beams 25. Then, the screen 24 of the color CRT 21
Has a color shift of about 0.1 mm.

Also, the permanent magnet shown in FIGS.
38 is attached to the outer periphery of the neck 31 and a geomagnetic shield plate
15-inch color CRT without 48
The three electron beams 25 generated from the in-line type electron gun 35 are appropriately moved along the axial direction of the permanent magnet 38 to change the position of the main magnetic field 43 by using the three electron beams 21. When focusing 25, the screen of color CRT 21
24 had a color shift of about 0.03 mm.

As described above, when three electron beams 25 are focused using the permanent magnet 38 shown in FIGS. 18 to 20, the permanent magnet 38 forms a main magnetic field 43 along the axial direction. Therefore, since the influence of the geomagnetism is reduced, accurate focusing of the electron beam 25 can be easily performed without mounting the geomagnetic shield plate 48.

Next, another embodiment of the electron beam focusing method of the present invention will be described with reference to FIGS.

The embodiment shown in FIG. 21 to FIG.
This is a method of correcting a color shift caused by the positional accuracy of the in-line type electron gun 35 generated when the three electron beams 25 are focused by the main magnetic field 43.

First, as shown in FIGS. 21 (a) and 21 (b), the magnet was magnetized along the axial direction, and the inner peripheral portion 39 was magnetized with six poles along the circumferential direction at equal intervals. A cylindrical six-pole multiple permanent magnet 67 is formed. The six-pole multiple permanent magnet 67 is magnetized so that the magnetic flux density at a position separated from the inner peripheral surface by 7 mm in the direction of the central axis becomes about 0.1 mT. The six-pole multi-permanent magnet 67 is positioned coaxially with the irradiation direction of the green beam 33 at a position where the three electron beams 25 pass through the inner peripheral portion.
It is arranged in the vicinity of the outer peripheral portion of the neck portion 21.

Next, the 15-inch type color cathode ray tube 21 is operated, a cross hatch signal is generated by the pattern generator 66, and the cross hatch signal is inputted from the cathode ray tube driving circuit 72 to the color cathode ray tube 21. Then, three electron beams 25, a red beam 32, a green beam 33, and a blue beam 34, are generated from the three in-line electron guns 35, and the red beam 32 is displayed on the screen 24 of the color CRT 21.
The state where the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 by the 32, green beam 33, and blue beam 34 are separated is displayed.

Then, the six-pole multi-permanent magnet 67 is appropriately moved along the axial direction, and as shown in FIG.
Red cross hatch pattern 68 and blue cross hatch pattern
Overlay with 70. Next, by appropriately rotating the six-pole multi-permanent magnet 67 around the axis and changing the sub-magnetic field 44 formed by the six-pole multi-permanent magnet 67, as shown in FIG. The blue cross hatch pattern 70 and the green cross hatch pattern 69 are overlapped to focus the three electron beams 25.

As described above, the color misregistration caused by the positional accuracy of the in-line type electron gun 35 changes the sub-magnetic field 44 by appropriately rotating the six-pole multiplex permanent magnet 67 forming the sub-magnetic field 44 about the axis. At the same time, when the six-pole multiplex permanent magnet 67 is appropriately moved along the axial direction, the color shift is corrected,
The positional accuracy of the in-line type electron gun 35 can be easily corrected.

As shown in FIG. 22, a six-pole multiple permanent magnet 67 having a six-pole permanent magnet 46 disposed coaxially is used.
The color shift caused by the positional accuracy of the in-line type electron gun 35 may be corrected. These six-pole multiple permanent magnets 67 and 6
When each of the pole permanent magnets 46 is appropriately rotated around the axis,
Since the multipole magnetic field orthogonal to the central axis changes, this color shift can be corrected. In addition, by appropriately rotating the six-pole multi-permanent magnet 67 and the six-pole permanent magnet 46 around the axis and moving them along the axial direction, the multipole magnetic field orthogonal to the central axis changes in a complicated manner. Color misregistration due to positional accuracy and the like can be corrected with high accuracy and in a wide range.

Also, instead of the six-pole multiple permanent magnet 67,
Even if the pole permanent magnet 46 is used, it is possible to correct the color shift caused by the positional accuracy of the in-line type electron gun 35 and the like.

Next, still another embodiment of the electron beam focusing method of the present invention will be described with reference to FIGS.

The embodiment shown in FIG. 25 to FIG.
The main magnetic field 43 depends on the position accuracy of the in-line type electron gun 35, etc.
Is a method of correcting a color shift that occurs when three electron beams 25 are focused.

First, as shown in FIGS. 25 (a) and 25 (b), a four-pole multi-permanent magnet 71 magnetized in the axial direction and having an inner peripheral portion magnetized to four poles at equal intervals. Is molded. The quadrupole permanent magnet 71 is magnetized so that the magnetic flux density at a position 7 mm away from the inner peripheral surface in the axial center direction is about 0.1 mT. Further, as shown in FIG. 25B, the four-pole multi-permanent magnet 71 is magnetized so that the magnetic flux density at the central point C on the central axis becomes about 0.35 mT.

The four-pole multi-permanent magnet 71 is positioned coaxially with the irradiation direction of the green beam 33 at a position where the three electron beams 25 pass through the inner peripheral portion. It is arranged near the outer peripheral portion of the neck portion 31.

Next, the color cathode ray tube 21 is operated, a cross hatch signal is generated by the pattern generator 66, and the color cathode ray tube 21 is output from the cathode ray tube driving circuit 72.
Input the cross hatch signal. Then, three electron beams 25 of a red beam 32, a green beam 33, and a blue beam 34 are generated from the three in-line electron guns 35, and the red beam 32, the green beam 33,
The state where the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 by the blue beam 34 are separated is displayed.

Then, the four-pole multiplex permanent magnet 71 is appropriately moved along the axial direction, and as shown in FIG. 26, each of the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 Are overlapped, and the vertical lines of the red cross hatch pattern 68 and the blue cross hatch pattern 70 are made closer to the vertical lines of the green cross hatch pattern 69. Then, the quadrupole permanent magnet 71 is appropriately rotated about its axis to change the sub magnetic field 44, and as shown in FIG. 27, the vertical lines of the red cross hatch pattern 68 and the blue cross hatch pattern 70 respectively. Is superimposed on a vertical line of the green cross hatch pattern 69 to focus the three electron beams 25.

As described above, when the four-pole multi-permanent magnet 71 is appropriately moved along the axial direction and rotated about the axis, when the three electron beams 25 are focused by the main magnetic field 43, the in-line type Since color misregistration caused by the positional accuracy of the gun 35 can be corrected, convergence adjustment and correction of the positional accuracy and the like can be easily performed by a series of operations.

It is to be noted that, even if a four-pole permanent magnet 45 or a four-pole multiple permanent magnet 71 having the four-pole permanent magnet 45 disposed coaxially is used instead of the four-pole multiple permanent magnet 71, The same operation and effect as when the multiple permanent magnets 71 are used can be obtained.

Next, still another embodiment of the electron beam focusing method of the present invention will be described with reference to FIGS.

The magnetic field forming means 36 of the embodiment shown in FIGS. 28 to 31 has an outer diameter of 37 mm, an inner diameter of 30 mm, and a height of 5 mm.
mm, a second coil 51 formed in the same shape as the first coil 50, and a cylindrical shape formed in a cylindrical shape having an inner diameter of 37 mm and a height of 10 mm along the axial direction. A magnetized permanent magnet 38 is provided.

In the magnetic field forming means 36, a second coil 51 is attached via a spacer 65 coaxially at a position 6 mm away from the first coil 50. A second coil 51 is coaxially mounted on the inner peripheral portion 39 of the permanent magnet 38 of the magnetic field forming means 36 via a spacer 65.

The first coil 50 and the second coil 51 are made of a polyurethane round copper wire having a diameter of 0.18 mm.
It is formed by winding 00 turns. The first coil 50 is connected to a first power supply 52 for supplying an appropriate current to the first coil 50, and the second coil 51 is similarly connected to the second coil 51. Pass the appropriate value of current to 51
Are connected. Further, the first coil 50 and the second coil 51 are formed to have a magnetic flux density of about 0.3 mT when a current of 100 mA flows.

Next, the permanent magnet 38 is
The center D point on the center axis of 38 is magnetized to have a magnetic flux density of 0.42 mT. Further, on the Z axis on the central axis of the magnetic field forming means 36, there is a magnetic field distribution characteristic shown in FIG.

Then, the magnetic field forming means 36 is turned on by the green beam 33.
The three electron beams 25 are arranged coaxially with each other in the irradiation direction, and are disposed near the outer periphery of the neck portion 31 of the 15-inch color cathode-ray tube 21 at the position where the three electron beams 25 pass through the inner periphery.

Here, the color cathode ray tube 21 is operated, a cross hatch signal is generated from the pattern generator 66, and a cross hatch signal is input from the cathode ray tube driving circuit 72 to the color cathode ray tube 21, and the inline type electron gun
From 35, a red beam 32, a green beam 33, and a blue beam 34 are generated. Then, the screen 24 of the color CRT 21
The red cross hatch pattern 68 and the green cross hatch pattern 6 by the red beam 32, the green beam 33, and the blue beam 34
9 and the state where the blue cross hatch pattern 70 is separated is displayed.

Then, the permanent magnet 38 is appropriately moved along the axial direction to obtain a red cross hatch pattern 68, a green cross hatch pattern 69, and a blue cross hatch pattern 70.
Overlay each vertical line. At this time, the magnetic field distribution characteristics shown in FIG. 29 move along the positive direction of the Z axis with the movement of the permanent magnet 38 along the axial direction.
Further, when the vertical lines of the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 overlap at the center of the screen 24, the vertical lines at the periphery of each screen 24 are The vertical lines of the red cross hatch pattern 68 and the blue cross hatch pattern 70 deviate from the vertical lines of the green cross hatch pattern 69 by about 0.2 mm in a bilaterally symmetric manner.

This is because, as shown in FIG.
2.Because the focusing positions of the green beam 33 and the blue beam 34 are different between the central part of the screen 24 and the peripheral part of the screen 24, the peripheral part of the screen 24 is smaller than the opening 29 of the shadow mask 39 of the color CRT 21. In-line type electron gun
This is because it is shifted to the side where 35 is located.

Next, the first power supply 52 supplies the first coil
A current of an appropriate value is supplied to the first coil 50 and a current of an appropriate value is supplied from the second power supply unit 53 to the second coil 51 in a direction opposite to the direction of the current applied to the first coil 50. Then, the main magnetic field 43 by the permanent magnet 38 is weakened. The magnetic field distribution characteristics on the central axis of the permanent magnet 38 at this time are as follows.
By passing a current through the coil 50 and the second coil 51, the values of the vertex M _{9 in} the positive direction and the vertex M _{10 in} the negative direction of the magnetic field distribution characteristics shown in FIG. 29 decrease. Then, the convergence position moves to the screen side, and the horizontal lines of the red cross hatch pattern 68 and the blue cross hatch pattern 70 approach the horizontal lines of the green cross hatch pattern 69, respectively. Then, at a certain current value, the horizontal lines of the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 overlap. At this time, the red beam 32, the green beam 33, and the blue beam 34 are focused on the opening 29 of the shadow mask 30 of the color CRT 21 as shown in FIG.

Further, when the main magnetic field 43 by the permanent magnet 38 is weakened by using the first coil 50 and the second coil 51, the horizontal line of the green cross hatch pattern 69 is shifted to the red cross hatch pattern 68. The horizontal lines of the blue cross hatch pattern 70 and the horizontal lines of the blue cross hatch pattern 70 are opposite to each other in the state before the overlap and shift symmetrically.

As described above, when the permanent magnet 38 is moved along the axial direction, the vertical lines of the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 overlap, and the first coil 50 and 2nd
When a current of an appropriate value is passed through the coil 51, the horizontal lines of the red cross hatch pattern 68, the green cross hatch pattern 69, and the blue cross hatch pattern 70 overlap,
The first coil 50 and the second coil 51 can correct the shift of the focusing position of the three electron beams 25 by the permanent magnet 38.

The electron beam focusing method shown in FIG. 9 mainly uses a magnetic field orthogonal to the irradiation direction of the green beam 33 and does not use a magnetic field in a direction along the irradiation direction of the green beam 33. When geomagnetism is applied from the outside in the direction along the irradiation direction of the green beam 33, the amount of change in the magnetic field in the direction along the irradiation direction of the green beam 33 changes from 0 to the intensity m of the external magnetic field. The rate is 1. On the other hand, the electron beam focusing method shown in FIGS. 28 to 31 applies a magnetic field in the direction along the irradiation direction of the green beam 33 to the main magnetic field.
Since the main magnetic field 43 forms a magnetic field of intensity M with respect to the three electron beams 25, the main magnetic field 43 extends along the irradiation direction of the green beam 33 with respect to the three electron beams 25 from the outside. The change rate when geomagnetism is formed is 1 or less. Therefore, since the magnitude of the magnetic field due to the terrestrial magnetism is about 0.03 mT, when the electron beam 25 is focused using the magnetic field forming means 36 shown in FIGS. The beam 25 can be easily focused.

In the electron beam focusing method shown in FIG. 14, the deflection coil 54 is connected to the neck portion 31 of the color CRT 21.
Of the deflection coil 54, a 4V power supply unit, a 4H power supply unit, a 6V power supply unit, and a 6H power supply unit. Is appropriately adjusted to correct the color shift of the electron beam 25 due to the positional accuracy of the in-line type electron gun 35. This deflecting coil 54 includes 20 coils and four circuits. is necessary. However,
In the electron beam focusing method shown in FIGS.
Since the three electron beams 25 are focused only by the two circuits that control the direction and magnitude of the current flowing through the first coil 50 and the second coil 51, the configuration is simplified and the manufacturing cost can be reduced.

A deflection yoke for deflecting the electron beam 25 coaxially with the neck 31 is attached to the outer periphery of the neck 31 of the color cathode ray tube 21. A magnetic field in a direction perpendicular to the direction is formed on the neck portion 31 of the color cathode-ray tube 21 to deflect the three electron beams 25. Also, in the electron beam focusing device shown in FIGS.
Three electron beams with main magnetic field 43 along the irradiation direction of
Deflected 25. Therefore, even if this deflection yoke is further attached to the electron beam focusing device shown in FIGS. 28 to 31 to deflect the three electron beams 25, there is little magnetic interference. Focusing on precision is possible.

When the permanent magnet 38 is fixed to the neck portion 31 of the color cathode-ray tube 21, the first coil 50
By passing currents of appropriate values from the first power supply section 52 and the second power supply section 53 to the second coil 51 and the second coil 51, respectively, the red cross hatch pattern beam 68, the green cross hatch pattern 69, and the blue cross hatch Vertical lines of the pattern 70 can also overlap.

As the focus of the three electron beams 25 moves away from the center of the screen 24 of the color cathode-ray tube 21 to the peripheral portion in the width direction, the first coil necessary to focus the electron beams 25 50 and second coil 51
Since the value of the current flowing through the first coil 50 and the second coil 51 is large, the waveform of the current wave flowing through the first coil 50 and the second coil 51 is, as shown in FIG. 32, a parabolic wave 73 having the waveform shown in FIG. FIG. 32 having a waveform shorter in wavelength than the parabolic wave 73
A composite parabolic wave 75 having a waveform shown in FIG. 32C, which is a composite of a parabolic wave 74 shown in FIG.

Further, the permanent magnet 38 of the magnetic field forming means 36 shown in FIG. 28 and FIG.
Alternatively, the dimensions and the magnetic field to be formed may be determined as appropriate depending on the deflection yoke to be combined.

[0172]

According to the first aspect of the present invention, a forward magnetic field having a magnetic field in a direction of irradiation of a green beam of an electron beam and a reverse magnetic field in a direction opposite to the forward magnetic field are coaxially arranged. Then, a main magnetic field is formed at a position near an electron beam generating side of the in-line type electron gun, and the bandwidth, direction, intensity, and position of the main magnetic field are appropriately changed to generate three electron beams. When deflected, the three electron beams are focused on the opening of the shadow mask, so that the adjustment when focusing the three electron beams can be easily performed.

According to the electron beam focusing method according to the second aspect, in addition to the effect of the electron beam focusing method according to the first aspect, a main magnetic field is formed by the substantially cylindrical first and second coils. In this case, when the electron beam is deflected by appropriately adjusting the value of the current flowing through each of the coils, the three electron beams are focused on the opening of the shadow mask, so that the current is passed through the first coil and the second coil. Since the three electron beams are focused only by appropriately adjusting the current, the focusing of the three electron beams can be easily adjusted.

According to the method for converging an electron beam according to the third aspect, in addition to the effect of the method for converging an electron beam according to the first aspect, a main magnetic field is generated by a substantially cylindrical permanent magnet magnetized along the axial direction. When the permanent magnet is appropriately moved along the axial direction, the three electron beams are focused on the opening of the shadow mask. Therefore, only three permanent beams are moved along the axial direction. Since the electron beams are focused, the focusing of the electron beams can be easily adjusted.

According to the method for converging an electron beam according to the fourth aspect, in addition to the effect of the method for converging an electron beam according to the first aspect, the three electron beams are appropriately moved along the axial direction of the permanent magnet. When the three electron beams are focused and fixed at a position where they are substantially focused, and the values of the currents supplied to the first coil and the second coil are appropriately adjusted to focus the three electron beams, the three electron beams are Are approximately focused beforehand, so that the current value flowing through the first coil and the second coil can be small, so that the focusing of the electron beam can be easily adjusted,
Also, after appropriately moving the permanent magnet along the axial direction to focus the three electron beams, and supplying an appropriate value of current to the first coil and the second coil, the in-line type electron gun can be used. Since the color shift of the three electron beams due to positional accuracy and the like is corrected, more accurate focusing adjustment of the electron beams can be easily performed.

According to the electron beam focusing method of the fifth aspect, in addition to the effect of the electron beam focusing method according to any one of the first to fourth aspects, the forward magnetic field in the irradiation direction of the green beam and the reverse of the forward magnetic field can be obtained. A main magnetic field in which a reverse magnetic field in the direction is arranged coaxially, and a sub-magnetic field having a multipolar magnetic field orthogonal to the irradiation direction of the green beam are arranged coaxially in the irradiation direction of the green beam. A deflection magnetic field is formed at a position near the side of the type electron gun that generates an electron beam, and the bandwidth of this deflection magnetic field is
By appropriately changing the direction, intensity, and position, the color shift due to the positional accuracy of the in-line type electron gun that occurs when three electron beams are focused by the main magnetic field is corrected. Beam focusing can be easily adjusted.

According to the electron beam focusing method of the sixth aspect, in addition to the effect of the electron beam focusing method of the fifth aspect, a substantially cylindrical magnet whose inner peripheral portion is magnetized in multiple poles along the circumferential direction. A sub-magnetic field is formed by a multipole permanent magnet having a shape. When the multipole permanent magnet is appropriately rotated around the axis and moved along the axial direction, when the three electron beams are focused using the main magnetic field, The color shift caused by the positional accuracy of the in-line type electron gun can be corrected, so the color generated by the position accuracy of the in-line type electron gun can be corrected by a series of focusing adjustments by rotating the multi-pole permanent magnet around the axis and moving along the axial direction. Since the deviation is corrected, it is possible to easily adjust the focusing of the electron beam more accurately.

According to the electron beam focusing apparatus of the seventh aspect, the magnetic field forming means is configured so that the forward magnetic field having the magnetic field in the direction of irradiation of the green beam and the reverse magnetic field having the magnetic field in the direction opposite to the forward magnetic field are coaxial. When the main magnetic field disposed in the shadow mask is formed and the bandwidth, direction, intensity, and position of the main magnetic field are appropriately changed by the convergence adjusting means, three electron beams converge on the opening of the shadow mask. The focus adjustment of the three electron beams can be easily performed, and the configuration for adjusting the focus of the electron beams can be simplified, so that the productivity of the apparatus main body can be improved.

According to the electron beam focusing apparatus of the eighth aspect, in addition to the effect of the electron beam focusing apparatus of the seventh aspect, the magnetic forming means can be formed by the first and second coils having a substantially cylindrical shape. When the currents flowing through the first coil and the second coil are appropriately changed by the convergence adjusting means when the main magnetic field is formed, three electron beams are focused on the opening of the shadow mask. Since the electron beam is focused only by changing the value of the current flowing through the second coil and the second coil, the focusing of the electron beam can be easily adjusted.

According to the electron beam focusing device of the ninth aspect, in addition to the effect of the electron beam focusing device of the seventh aspect, in addition to the substantially cylindrical permanent magnet magnetized along the axial direction,
When the main magnetic field of the magnetic forming unit is formed, the three electron beams are focused on the opening of the shadow mask when the convergence adjusting unit appropriately moves the permanent magnet along the axial direction.
Since the electron beam is focused only by moving the permanent magnet along the axial direction, the focusing of the electron beam can be easily adjusted, and the device for focusing the electron beam is simplified, thereby improving the manufacturability of the device body. it can.

According to the electron beam focusing device of the tenth aspect, in addition to the effect of the electron beam focusing device of the seventh aspect, a permanent magnet is positioned and fixed in advance at a position where three electron beams are substantially focused. When an appropriate value of current is supplied to the first coil and the second coil to further focus the three electron beams, the current value supplied to the first coil and the second coil can be small. When the three electron beams are focused by a permanent magnet and then focused by a first coil and a second coil, the focusing of the three electron beams can be easily adjusted. In addition, since the color misregistration due to the positional accuracy of the in-line type electron gun is corrected, more accurate adjustment of the electron beam convergence can be easily performed, and the configuration is simplified, so that the productivity can be improved.

According to the electron beam focusing device of the eleventh aspect, in addition to the effect of the electron beam focusing device according to any one of the seventh to tenth aspects, the magnetic forming means sets the main magnetic field and the sub magnetic field to the green beam. When a deflection magnetic field is formed coaxially with the irradiation direction, and the bandwidth, direction, intensity, and position of the deflection magnetic field are appropriately changed by the focusing adjustment means, the three electron beams are converted into a shadow mask. Focusing on the aperture of the electron beam facilitates accurate focusing adjustment of the electron beam, and color shift due to the positional accuracy of the in-line type electron gun that occurs when the main magnetic field of the magnetic field forming means is adjusted to focus the electron beam However, since the correction can be made by the sub-magnetic field of the magnetic field forming means, it is possible to easily adjust the focusing of the electron beam more easily. .

According to the electron beam focusing apparatus according to the twelfth aspect, in addition to the effect of the electron beam focusing apparatus according to the eleventh aspect, in addition to the effect of the electron beam focusing apparatus according to the eleventh aspect, a substantially cylindrical magnet whose inner peripheral portion is magnetized in multiple poles along the circumferential direction. When the multi-pole permanent magnet forms a sub-magnetic field of the magnetic forming means with the shape of the magnet, and the convergence adjusting means rotates the multi-pole permanent magnet appropriately around the axis and moves along the axial direction, the three electron beams are mainly emitted. Since the color shift due to the positional accuracy of the in-line type electron gun caused by focusing with a magnetic field is corrected, the focusing of the electron beam can be adjusted more easily, and the magnetic field forming means is simplified. Can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of an electron beam focusing apparatus according to the present invention.

FIG. 2 is an explanatory view showing a part of the magnetic field forming means. (A) Front view of a part of the magnetic field forming means (b) aa of a part of the magnetic field forming means shown in FIG.
Sectional view

FIG. 3 is an explanatory diagram showing a magnetic field distribution by a part of the magnetic field forming means shown in FIG. 2;

FIG. 4 is an explanatory diagram showing magnetic field distribution characteristics on a central axis of a part of the magnetic field forming means shown in FIG. 2;

FIG. 5 is an explanatory diagram showing how the electron beam is focused.

FIG. 6 is an explanatory diagram showing a focusing method of the electron beam according to the first embodiment.

FIG. 7 is an explanatory diagram showing a focusing method of the electron beam according to the third embodiment.

FIG. 8 is an explanatory diagram showing a focusing method of the electron beam according to the first embodiment.

FIG. 9 is a cross-sectional view showing a part of a comparative example for explaining the electron beam focusing device of the present invention.

FIG. 10 is an explanatory view showing a magnetic field distribution by a magnetic forming means in another embodiment of the electron beam focusing apparatus of the present invention.

FIG. 11 is an explanatory diagram showing a magnetic field distribution characteristic on a central axis of a part of the magnetic field forming means shown in FIG. 10;

FIG. 12 is an explanatory view showing a magnetic field distribution by a part of a magnetic forming means in still another embodiment of the electron beam focusing apparatus of the present invention.

FIG. 13 is an explanatory diagram showing a magnetic field distribution characteristic on the central axis of the magnetic field forming means shown in FIG. 12;

FIG. 14 is a plan view showing a part of another comparative example for explaining the electron beam focusing device of the present invention.

FIG. 15 is a cross-sectional view showing a part of a magnetic forming means in still another embodiment of the electron beam focusing apparatus of the present invention.

FIG. 16 is a cross-sectional view showing a part of a magnetic forming means in still another embodiment of the electron beam focusing apparatus of the present invention.

FIG. 17 is a cross-sectional view showing a part of a magnetic forming means in still another embodiment of the electron beam focusing apparatus of the present invention.

FIG. 18 is a plan view showing a part of the magnetic forming means in the embodiment of the electron beam focusing apparatus of the present invention. (A) Front view of a part of the magnetic field forming means (b) b- of a part of the magnetic field forming means shown in FIG.
b sectional view

FIG. 19 is an explanatory diagram showing a magnetic field distribution by a part of the magnetic field forming means shown in FIG. 18;

FIG. 20 is an explanatory diagram showing a magnetic field distribution characteristic on a central axis of a part of the magnetic field forming means shown in FIG. 18;

FIG. 21 is a plan view showing a part of a magnetic forming means in another embodiment of the electron beam focusing apparatus of the present invention. (A) Front view of a part of the magnetic field forming means (b) c- of a part of the magnetic field forming means shown in FIG.
c sectional view

FIG. 22 is an explanatory view showing another embodiment of a part of the magnetic forming means. (A) Front view of part of magnetic field forming means (b) d- of part of magnetic field forming means shown in FIG.
d sectional view

FIG. 23 is an explanatory diagram showing how the electron beam is focused.

FIG. 24 is an explanatory diagram showing how the electron beam is focused.

FIG. 25 is a plan view showing a part of magnetic forming means in still another embodiment of the electron beam focusing apparatus of the present invention. (A) Front view of part of magnetic field forming means (b) e-part of magnetic field forming means shown in FIG.
e cross section

FIG. 26 is an explanatory diagram showing how the electron beam is focused.

FIG. 27 is an explanatory diagram showing how the electron beam is focused.

FIG. 28 is a sectional view showing a part of the magnetic forming means in still another embodiment of the electron beam focusing apparatus of the present invention.

FIG. 29 is an explanatory diagram showing a magnetic field distribution characteristic on a central axis of a part of the magnetic field forming means shown in FIG. 28;

FIG. 30 is an explanatory diagram showing how the electron beam is focused.

FIG. 31 is an explanatory diagram showing how the electron beam is focused.

FIG. 32 is an explanatory diagram showing a composite parabolic wave according to the third embodiment; (A) Explanatory diagram showing the waveform of a parabolic wave (b) Explanatory diagram showing the waveform of a parabolic wave (c) Explanatory diagram showing the waveform of a composite parabolic wave

FIG. 33 is an explanatory view showing a part of a magnetic field forming means in the form of a conventional electron beam focusing device. (A) Partial front view of magnetic field forming means (b) Partial side view of magnetic field forming means

FIG. 34 is a front view showing a part of a magnetic field forming means of another embodiment of the conventional electron beam focusing device.

FIG. 35 is a front view showing a part of a magnetic field forming means of still another embodiment of the conventional electron beam focusing device.

FIG. 36 is a front view showing a part of a magnetic field forming means of still another embodiment of the conventional electron beam focusing device.

FIG. 37 is a front view showing a part of the magnetic field forming means of still another embodiment of the conventional electron beam focusing device.

FIG. 38 is an explanatory view showing a conventional electron beam focusing method.

FIG. 39 is an explanatory view showing a conventional electron beam focusing method.

[Explanation of symbols]

 21 color cathode ray tube 23 three-color fluorescent film 24 screen 25 electron beam 29 aperture 30 shadow mask 31 neck 32 red beam 33 green beam 34 blue beam 35 in-line type electron gun 36 magnetic field forming means 37 focusing adjustment means 38 permanent magnet 39 inner circumference Unit 40 multi-pole permanent magnet 41 forward magnetic field 42 reverse magnetic field 43 main magnetic field 44 auxiliary magnetic field 47 deflecting magnetic field 50 first coil 51 second coil 52 first power supply unit 53 second power supply unit

Claims (12)

[Claims] 1. Three red beams generated from an in-line type electron gun mounted on a neck portion of a color cathode ray tube;
An electron beam for converging an electron beam of a green beam and a blue beam to an opening of a shadow mask of the color cathode-ray tube, and irradiating the three-color fluorescent film of the screen of the color cathode-ray tube with the red, green and blue beams, respectively. In the beam focusing method, a forward magnetic field having a magnetic field in the irradiation direction of the green beam and a reverse magnetic field having a magnetic field in a direction opposite to the forward magnetic field are provided at positions near the electron beam generating side of the in-line type electron gun. A main magnetic field is formed by arranging at least one or more magnetic fields coaxially with the irradiation direction of the green beam, and at least one of at least one of a bandwidth, a direction, an intensity, and a position of the main magnetic field; To deflect at least one of the red, green, and blue beams; and to deflect the red, green, and blue beams. Focusing method of an electron beam, characterized in that focusing on the opening of the shadow mask. 2. A main magnetic field includes a substantially cylindrical first coil connected to a first power supply, and a substantially cylinder disposed coaxially with the first coil and connected to a second power supply. At least one of the second coils is coaxial with the irradiation direction of the green beam and is located at a position where the red, green, and blue beams pass through the inner peripheral portion. 2. The method for focusing an electron beam according to claim 1, wherein the electron beam is formed by being arranged on an outer peripheral portion. 3. The main magnetic field includes at least one or more permanent magnets formed in a substantially cylindrical shape and magnetized along the axial direction, coaxially with the irradiation direction of the green beam and the red, green, and blue beams. It is the position where the beam passes through the inner circumference,
2. The electron beam focusing method according to claim 1, wherein said electron beam is formed by being arranged on an outer peripheral portion of a neck portion of said color cathode ray tube. 4. A main magnetic field includes a substantially cylindrical first coil connected to a first power supply, and a substantially cylinder disposed coaxially with the first coil and connected to a second power supply. At least one or more of a second coil and a permanent magnet formed in a substantially cylindrical shape and magnetized along the axial direction, coaxially with a green beam irradiation direction and a red beam, a green beam, and 2. The electron beam focusing method according to claim 1, wherein the blue beam is located at a position where the blue beam passes through an inner peripheral portion, and is formed on an outer peripheral portion of a neck portion of the color cathode ray tube. 5. An in-line type electron gun in which at least one of a main magnetic field and at least one sub-magnetic field having a multipole magnetic field orthogonal to the irradiation direction of a green beam is provided at a position near an electron beam generating side. A deflection magnetic field is formed by being arranged coaxially with the irradiation direction of the green beam. A red beam, a green beam by changing at least one of the bandwidth, direction, intensity, and position of the deflection magnetic field. And deflecting at least one of the blue beam and the red beam, the green beam, and the blue beam to focus the aperture of the shadow mask. Focusing method. 6. A sub-magnetic field is generated by applying a multi-pole permanent magnet, which is formed into a substantially cylindrical shape and whose inner peripheral portion is magnetized to multiple poles along the circumferential direction, on the same axis as the irradiation direction of the green beam and with the red and green beams. 6. The electron according to claim 5, wherein at least one of the beam and the blue beam passes through the inner peripheral portion and is arranged at least one at the outer peripheral portion of the neck portion of the color cathode-ray tube. How to focus the beam. 7. Three red beams generated from an in-line type electron gun mounted on a neck portion of a color cathode ray tube,
An electron beam for converging an electron beam of a green beam and a blue beam to an opening of a shadow mask of the color cathode-ray tube, and irradiating the three-color fluorescent film of the screen of the color cathode-ray tube with the red, green and blue beams, respectively. In the beam focusing device, a forward magnetic field having a magnetic field in a direction of irradiation of the green beam and a reverse magnetic field having a magnetic field in a direction opposite to the forward magnetic field are provided at a position near a side of the in-line type electron gun that generates the electron beam. Magnetic field forming means for forming a main magnetic field by arranging at least one of the magnetic fields coaxially with the irradiation direction of the green beam; bandwidth, direction, intensity, and position of the main magnetic field of the magnetic field forming means By changing at least one of the red beam, the green beam, and deflects at least one of the blue beam, the red beam, Beam, and focusing device of the electron beam of the blue beam characterized by comprising a focusing adjusting means for focusing the opening of the shadow mask. 8. The main magnetic field of the magnetic field forming means is connected to the first cylindrical coil connected to the first power supply unit and to the second power supply unit disposed coaxially with the first coil. At least one of the formed substantially cylindrical second coils is positioned coaxially with the direction of irradiation of the green beam and at a position where the red, green, and blue beams pass through the inner peripheral portion. 8. The electron beam focusing device according to claim 7, wherein the electron beam focusing device is formed by being disposed on an outer peripheral portion of the neck portion. 9. The main magnetic field of the magnetic field forming means is configured to apply at least one or more permanent magnets formed in a substantially cylindrical shape and magnetized along the axial direction to the same direction as the irradiation direction of the green beam and to the red and green beams. 8. The electron beam focusing apparatus according to claim 7, wherein the beam and the blue beam are located at positions where they pass through the inner peripheral portion, and are formed on the outer peripheral portion of the neck portion of the color cathode ray tube. . 10. The main magnetic field of the magnetic field forming means includes a substantially cylindrical first coil connected to a first power supply unit,
At least one of a substantially cylindrical second coil disposed coaxially with the second power supply unit and connected to the second power supply unit; and a permanent magnet formed into a substantially cylindrical shape and magnetized along the axial direction. One or more, coaxial with the irradiation direction of the green beam and the red beam,
8. The focusing of an electron beam according to claim 7, wherein the green beam and the blue beam are located at positions where they pass through an inner peripheral portion, and are disposed on an outer peripheral portion of a neck portion of the color cathode-ray tube. apparatus. 11. An in-line type electron gun in which at least one of each of a main magnetic field and a sub-magnetic field having a multi-pole magnetic field orthogonal to the irradiation direction of a green beam is provided at a position near an electron beam generating side. Magnetic field forming means disposed coaxially with the direction of irradiation of the green beam to form a deflecting magnetic field; and changing at least one of the bandwidth, direction, intensity, and position of the deflecting magnetic field of the magnetic field forming means. And focusing means for deflecting at least one of the red beam, the green beam, and the blue beam to focus the red beam, the green beam, and the blue beam on the opening of the shadow mask. An electron beam focusing apparatus according to any one of claims 7 to 10. 12. A sub-magnetic field of the magnetic field forming means is formed by a multi-pole permanent magnet which is formed in a substantially cylindrical shape and whose inner peripheral portion is multi-pole magnetized along the circumferential direction, coaxially in the green beam irradiation direction and The red beam, the green beam, and the blue beam are located at positions where they pass through the inner peripheral portion, and at least one is disposed and formed on the outer peripheral portion of the neck portion of the color cathode-ray tube. 12. An electron beam focusing apparatus according to claim 11.