JP3348867B2 - Method of manufacturing color picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color picture tube, and more particularly to a method of manufacturing a color picture tube by disposing a magnetic body at a predetermined position in a neck with respect to an electron gun arranged in the neck. The present invention relates to a method for manufacturing a color picture tube for adjusting the trajectories of a plurality of electron beams emitted from an electron gun by locally magnetizing the magnetic material from outside the neck.

[0002]

2. Description of the Related Art As shown in FIG. 5, a color picture tube generally has a panel 1 and an envelope composed of a funnel 2 integrally joined to the panel 1, and is arranged in a neck 3 of the funnel 2. 3 electron beams emitted from the installed electron gun 4
Deflection yoke 6 with 5B, 5G, 5R mounted outside funnel 2
The screen is deflected by the magnetic field generated, and the phosphor screen 8 formed on the inner surface of the panel 1 is horizontally and vertically scanned through a shadow mask 7 arranged inside the panel 1, thereby obtaining the phosphor screen. 8 is configured to display a color image.

In order to improve the quality of a color image drawn on the phosphor screen 8, the three electron beams 5B, 5G, 5R emitted from the electron gun 4 are concentrated on one point on the phosphor screen 8 ( (Static convergence) and the three electron beams 5B, 5G, and 5R must properly land the three-color phosphor layers constituting the phosphor screen 8 so that a predetermined color purity can be obtained. However, the actually manufactured color picture tube has an electron beam 5 due to an assembly error of the electron gun 4 and an assembly error of the color picture tube itself.
Concentration of B, 5G, 5R and 3 electron beams 5 for 3 color phosphor layer
The landing of B, 5G, 5R shifts, and the screen quality deteriorates.

For this reason, a magnet is attached to an ordinary color picture tube in order to correct static convergence and landing deviation. In the color picture tube shown in FIG.
The magnet 9 is mounted outside the neck 3. Usually, this magnet 9 has two poles along the periphery of a substantially annular magnetic body,
Consisting of three sets of permanent magnets, one set of two magnets forming four poles and six poles, each set of magnets being rotated,
Static convergence and color purity are adjusted by appropriately shifting the pair of magnetic poles in the circumferential direction.

[0005] However, the method of adjusting static convergence and color purity using three sets of permanent magnets consisting of a pair of two magnets requires not only skill but a considerable amount of time for adjustment, and adjustment work. Being empirical,
It is difficult to make accurate and sufficient adjustments.

To compensate for the problem caused by the external magnet, as shown in FIG. 6, a magnetizable substantially annular magnetic body 11 is arranged between the electron gun 4 and the inner wall of the neck 3 so as to form a color picture tube. At the time of adjustment after completion of assembly, the magnetic body 11
It is known that a magnetic pole is formed by magnetizing two poles, four poles, six poles, twelve poles or the like by a magnetizing device arranged outside to adjust static convergence and color purity in the same manner as the above color picture tube. I have.

Japanese Patent Publication No. 59-33931 discloses a method of magnetizing a color picture tube in which a magnetic substance is disposed in the neck, in which static convergence and color purity are adjusted in advance by an adjusting auxiliary device. A method (first method) of supplying adjustment information obtained from the device to a magnetizing device, controlling a magnetic field generated by the magnetizing device, and magnetizing a magnetic body is shown.

However, in this method, when the magnetic material is polarized and magnetized in multiple poles, it is difficult to accurately control the magnetization state. That is, in this method, for example, two poles, four
When the poles and the six poles are formed in combination, the magnetized poles are apt to change, and because of the magnetization characteristics of the magnetic material,
The magnetization intensity of the magnetic pole at the exact position of the magnetic pole to be formed cannot have a linear relationship with the magnetizing magnetic field generated by the magnetizing device. Therefore, in this method, it is extremely difficult to form a combination of a plurality of magnetic poles. Further, when a plurality of magnetic poles are formed in combination, the magnetization characteristics of other portions of the magnetic material change, so that the magnetic poles cannot be formed by a method of sequentially magnetizing the plurality of magnetic poles. Further, since the distance between the magnetic body in the neck and the magnetizing magnetic pole of the magnetizing device is large, it is difficult to precisely control the magnetic flux.

In Japanese Patent Publication No. 61-6966,
A method (second method) of magnetizing by applying an attenuated alternating magnetic field that magnetizes into a saturated state on both sides of a hysteresis curve of a magnetic body is shown.

In this case, after the alternating magnetic field is attenuated, hard magnetization matching the external magnetic field remains in the magnetic material. However, in this method, it is necessary to apply an attenuated alternating magnetic field that varies equally to the entire magnetic body in order to allow the magnetized portion having a linear relationship with the external magnetic field to remain in the magnetic body. Further, it is necessary to set the initial maximum value of the damping alternating magnetic field to 3 to 4 times the holding force. Therefore, if the magnetic body is formed from a magnetic material having a large coercive force, the initial maximum value of the attenuated alternating magnetic field must be made considerably large, and it becomes difficult to generate such a large magnetic field. Therefore, this method requires a magnetic
Not suitable for sex .

Furthermore, Japanese Patent Publication No. 63-7420 discloses that a magnetic material is heated to a temperature below its magnetic transformation point or a high temperature at which spontaneous magnetization disappears, and an external magnetic field is applied to the magnetic material to obtain a predetermined magnetic material. A method of forming a predetermined magnetic pole at a position (third method) is shown.

According to this method, the hard magnetization can be left in the magnetic material, and a magnetic field having a desired strength required for adjusting the static convergence and the color purity of the color picture tube can be formed.

However, in the first to third methods disclosed in the above publications, for example, when two magnetic bodies are attached to an electron gun and each of the magnetic bodies has a different function, the magnets are separately magnetized. Can not do. Because, in the first and second methods, the magnetic flux generated from the magnetizing device arranged outside the neck spreads to reach the magnetic material,
Not only the desired magnetic material but also another magnetic material is magnetized. Also in the third method, when a desired magnetic material is heated using a high-frequency induction heating coil, the magnetic field generated from the high-frequency induction heating coil spreads over a wide range, so that not only the desired magnetic material but also another magnetic material can be used. Also heat. Therefore, not only a desired magnetic material but also another magnetic material is magnetized. Furthermore, one magnetic body was attached to the electron gun, and this one
In the case where a plurality of kinds of adjustments for correcting the trajectory of an electron beam are performed by using a plurality of magnetic bodies, the first to third methods described above require
It is necessary to form magnetic poles necessary for adjusting all of them at once, but there is a problem that such magnetization is difficult.

[0014]

As described above, a magnetizable substantially annular magnetic body is conventionally disposed between the electron gun and the inner wall of the neck, and the adjustment is performed during the adjustment after the completion of the assembly of the color picture tube. The magnetizing device with the magnetic material placed outside the neck
2. Description of the Related Art A color picture tube is known which polarizes, polarizes, polarizes, polarizes, polarizes, and forms a magnetic pole to form plural magnetic poles, and performs a plurality of kinds of adjustments to correct electron beam trajectories such as static convergence and color purity. . However, according to a known method of magnetizing a magnetic body disposed in the neck, for example, when two magnetic bodies are disposed in the neck and each of the magnetic bodies has a different function, the magnets cannot be separately magnetized. . When one magnetic body is arranged in the neck and a plurality of kinds of adjustments for correcting the trajectory of the electron beam are performed by this one magnetic body, magnetic poles necessary for adjusting all of them at once are formed. However, there is a problem that such magnetization is difficult.

The present invention has been made to solve the above-mentioned problems. For example, two magnetic bodies are arranged between an electron gun and an inner wall of a neck, and the two magnetic bodies have different functions. When they are separately magnetized to give them, even if one magnetic body is magnetized, the other magnetic body is not affected by the magnetization, and one magnetic body is arranged. When a plurality of different functions are provided, an object of the present invention is to enable the different functions to be independently provided.

[0016]

According to the present invention, at least one magnetizable magnetic material is disposed at a predetermined position in a neck of an electron gun for emitting a plurality of electron beams disposed in the neck of an envelope. After the assembly of the color picture tube, the magnetic body is heated to a temperature below the magnetic transformation point or to the extent that spontaneous magnetization disappears, and an external magnetic field is applied to the magnetic body after or before the heating to form a predetermined magnetic pole. In the method of manufacturing a color picture tube in which the trajectory of an electron beam is adjusted by a laser beam, a predetermined position of a magnetic body is irradiated with laser light from outside the neck to locally heat the magnetic body below a magnetic transformation point or to an extent that spontaneous magnetization disappears. Then, an external magnetic field was applied to the heated portion to locally magnetize the heated portion.

[0017]

As described above, when a predetermined position of a magnetic body is irradiated with a laser beam to heat the magnetic body to a temperature lower than a magnetic transformation point or to an extent that spontaneous magnetization disappears, the heating is performed by the laser beam. A predetermined position of the magnetic body can be locally heated to a high temperature, and only the heated portion can be locally magnetized. Therefore, for example, when two magnetic materials are separately magnetized so as to have different functions, it is necessary that even if one magnetic material is magnetized, the other magnetic material is not affected by the magnetization. it can. Also, when a plurality of magnetic poles are formed on one magnetic body, each magnetic pole can be provided independently without affecting other magnetic poles.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments.

FIG. 2 shows the structure of a color picture tube manufactured by the manufacturing method according to the embodiment. This color picture tube has a panel 1 and an envelope composed of a funnel 2 integrally joined to the panel 1, and a shadow mask having a large number of electron beam passage holes formed inside the panel 1. On the inside of panel 1, facing blue,
A phosphor screen 8 including a three-color phosphor layer that emits green and red light is formed. Also, funnel 2 neck 3
An electron gun 4 is arranged inside.

This electron gun 4 is an electron gun that emits three electron beams 5B, 5G, 5R arranged in a line composed of a center beam 5G and a pair of side beams 5B, 5R passing on the same plane, as shown in FIG. So, three cathodes K arranged in a row
(Only one is shown in the drawing), three heaters (not shown) for heating each of the cathodes K, and each of the cathodes K is arranged adjacent to the cathode screen side of the cathode K in order.
A plurality of electrodes G1 to G, which control the emission of electrons from K, focus the emitted electrons into an electron beam, and accelerate and focus this electron beam toward the phosphor screen.
5, and a convergence cup C attached to the final electrode G5, the cathode K, the heater and the plurality of electrodes G1 to G5 are integrally fixed by a pair of insulating supports 20, 20. I have.

Further, in the color picture tube of this embodiment, a magnetic pole for adjusting the trajectory of the electron beam is formed between the predetermined electrode of the electron gun 4 and the inner wall of the neck 3. The magnetic bodies 21a and 21b are arranged.
In the illustrated example, the two magnetic bodies 21a and 21b are respectively arranged outside the bottom of the convergence cup C and outside the electrode G4. In particular, the magnetic body 21b arranged outside the electrode G4 is a pair of insulating supports. It is arranged to surround the outside of the bodies 20,20.

In manufacturing the color picture tube, a phosphor screen 8 is formed on the inner surface of the panel 1 in the same manner as a normal color picture tube, and the panel 1 on which the phosphor screen 8 is formed is formed.
After attaching the shadow mask 7 inside the panel,
1 is joined to funnel 2 integrally. Next, in the neck 3 of the funnel 2, a magnetizable magnetic material
21a and 21b seal and evacuate the electron gun 4 attached at a predetermined position. Thereafter, in the inspection process of the assembled color picture tube, in order to adjust the trajectories of the electron beams 5B, 5G, and 5R emitted from the electron gun 4, the magnetic material 21a disposed in the neck 3 together with the electron gun 4 is used. , 21b are magnetized as follows.

As shown in FIG. 1, the magnetization of the magnetic bodies 21a and 21b is performed by disposing the magnetizing device 22 at a position facing the magnetic body 21a or 21b outside the neck 3.

The magnetizing device 22 includes the magnetic members 21a, 21b
One or more magnetic pole forming parts 23 capable of polarizing and magnetizing one or a plurality of magnetic poles necessary for adjusting the trajectory of the electron beam. The magnetic pole forming portion 23 is composed of a coil 24 for generating a magnetic field necessary for forming a magnetic pole and a magnetic permeability for concentrating a magnetic field generated from the coil 24 on a portion of the magnetic bodies 21a and 21b where a magnetic pole is to be formed. High core 25
And a laser beam for locally heating the portions of the magnetic bodies 21a and 21b where the magnetic poles are to be formed to a temperature below the magnetic transformation point of the magnetic bodies 21a and 21b or a temperature at which the spontaneous magnetization disappears. Optical fiber 26 and this optical fiber 26
Lens optical system 27 for appropriately condensing and diverging laser light from
And In particular, in the magnetization device 22 shown in FIG. 1, the optical fiber 26 passes through the inside of the core 25.

The polarization magnetization of the magnetic poles necessary for adjusting the trajectories of the electron beams 5B, 5G and 5R is, for example, as shown in FIG. 3 and FIG. The magnetic pole forming part 23 of the magnetizing device 22 is arranged outside the neck 3, and the magnetic material 21 is first passed through the optical fiber 26.
A part of the magnetic pole a is irradiated with a laser beam 29, and the part of the magnetic pole is heated to a temperature below the magnetic transformation point or a temperature at which spontaneous magnetization disappears. The irradiation range of the laser light 29 at this time is adjusted by the lens optical system 27. After or before heating by the laser beam 29, a DC current adjusted to generate a magnetic field necessary for forming a magnetic pole having a desired magnetic field strength is passed through the coil 24 of the magnetic pole forming unit 23, and The portion heated to a temperature below the magnetic transformation point or a temperature at which spontaneous magnetization disappears is magnetized.

The magnetization of the magnetic body 21b is performed in the same manner.

Further, when a plurality of magnetic poles are polarized and magnetized on one magnetic body 21a or 21b, the magnetic pole forming portions 23 are sequentially arranged facing portions where the plurality of magnetic poles are to be formed.
The above-described magnetic pole forming method is repeated, or a plurality of magnetic pole forming portions are provided in the magnetizing device, and the magnetic pole forming portions are arranged to face the portions of the magnetic body where a plurality of magnetic poles are to be formed, respectively. A laser beam is applied to a portion where each magnetic pole is to be formed through an optical fiber disposed at a temperature, and locally heated to a temperature below a magnetic transformation point or a temperature at which spontaneous magnetization disappears, and forming each magnetic pole. A plurality of magnetic poles may be simultaneously polarized and magnetized by supplying a direct current for generating a magnetic field necessary for forming magnetic poles of a desired magnetic field strength to the coils of the respective sections.

By the way, as described above,
Magnetizable bodies 21a, 21b between the inner wall 4 and the neck 3
After the assembling of the color picture tube, when the magnetic poles necessary for adjusting the trajectories of the electron beams 5B, 5G, 5R are formed on the magnetic bodies 21a, 21b, the magnetic bodies 21a, 21b are formed. Laser light is applied to the part where the magnetic pole of 21b is to be formed
Irradiate the laser beam 29 to a temperature below the magnetic transformation point or a temperature at which spontaneous magnetization disappears.
After heating by or before heating, when a magnetic field is applied to a portion where the magnetic pole is to be formed and magnetized, it is possible to heat only the magnetic pole forming portion by laser light 19,
When the magnetic bodies 21a and 21b are arranged close to each other and magnetized so that they have different functions, even if one magnetic body is magnetized, the other magnetic body is not affected by the magnetization. be able to. Also, one magnetic substance 21a or 21
Similarly, when a plurality of magnetic poles are formed in b, independent magnetization can be performed without affecting other magnetic poles. Therefore, according to this magnetizing method, it is possible to easily form a magnetic pole for correcting the trajectory of the electron beam as expected.

In the above-described embodiment, the optical fiber for transmitting the laser light is disposed inside the core of the magnetic pole forming portion. However, this optical fiber is used to guide the laser light to the portion where the magnetic pole of the magnetic material is to be formed. And it may be arranged outside the magnetic pole forming portion.

[0030]

According to the present invention, at least one magnetizable magnetic body is arranged at a predetermined position in the neck with respect to the electron gun arranged in the neck, and after the assembly of the color picture tube is completed, the magnetic body is changed to a magnetic transformation point. In order to adjust the trajectory of the electron beam by applying an external magnetic field to the magnetic body after or before heating to form a predetermined magnetic pole after heating or to the extent that spontaneous magnetization disappears, the magnetic body from outside the neck locally irradiated with laser light at a predetermined position to heat the magnetic material to the extent that locally the magnetic transformation point or spontaneous magnetization disappears, the addition of external magnetic field to the heated portion, a predetermined position of the magnetic body To a high temperature, and only the heated portion can be locally magnetized. Therefore, for example, when two magnetic materials are separately magnetized to have different functions, even if one magnetic material is magnetized, the other magnetic material is not affected by the magnetization. be able to. Further, even when one magnetic body has a plurality of different functions, the different functions can be independently provided. As a result, a magnetic pole that corrects the trajectory of the electron beam as expected can be easily formed.

[Brief description of the drawings]

FIG. 1 is a view showing a magnetic body and a magnetizing device arranged in an electron gun of a color picture tube according to an embodiment of the present invention.

FIG. 2 is a diagram showing an overall configuration of a color picture tube in which a magnetic material is arranged on the electron gun.

FIG. 3 is a diagram for explaining a method of magnetizing a magnetic body arranged in the electron gun.

FIG. 4 is an enlarged view of a main part for explaining the magnetization method.

FIG. 5 is a diagram showing a configuration of a conventional color picture tube in which a permanent magnet is arranged outside a neck.

FIG. 6 is a view showing a configuration of a conventional color picture tube in which a magnetic material is arranged between an electron gun and an inner wall of a neck.

[Explanation of symbols]

 1 ... panel 2 ... funnel 3 ... neck 4 ... electron gun 5B, 5G, 5R ... 3 electron beam 8 ... phosphor screen 21a, 21b ... magnetic substance 22 ... magnetizing device 23 ... magnetic pole forming part 24 ... coil 25 ... core 26 ... Optical fiber 27… Lens optical system 29… Laser light

Claims (1)

(57) [Claims] 1. A color image receiving apparatus comprising: an electron gun configured to emit a plurality of electron beams disposed in a neck of an envelope; After assembling the tube, the magnetic material is heated to a temperature below the magnetic transformation point or to the extent that spontaneous magnetization disappears, and an external magnetic field is applied to the magnetic material after or before the heating to form a predetermined magnetic pole. A method for manufacturing a color picture tube for adjusting a beam trajectory, comprising irradiating a laser beam to a predetermined position of the magnetic body from outside the neck to locally lower the magnetic body below a magnetic transformation point or spontaneously.
A method for manufacturing a color picture tube, comprising heating the film to such an extent that the magnetization disappears, and locally magnetizing the heated portion by applying the external magnetic field.