JPH07322277A - Method and device for magnetism mapping for cathode ray tube - Google Patents

Abstract

PURPOSE:To obtain the magnetism mapping device in which magnetic mapping is implemented simply by applying effectively magnetism mapping to a cathode ray tube and surely correcting a change in a landing pattern even when the change is caused by mechanical deviation of a color selection electrode or the like so as to prevent mis-landing of an electron beam thereby preventing color smear. CONSTITUTION:Magnetism is mapped to a frame supporting a color selection electrode of a cathode ray tube therearound in the tube axis direction by providing an AC attenuation magnetic field having a tube axis direction component to the frame while a DC bias magnetic field having the tube axis direction component is applied to the frame. The magnetism mapping device is provided with 1st and 2nd coils 21, 22 surrounding the vicinity of a frame 4 supporting the color selection electrode 3 therearound for the cathode ray tube and magnetism is mapped to the frame while a DC bias magnetic field is received by the 1st coil by providing an AC attenuation magnetic field by the 2nd coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube (CRT) used in a TV or the like, and more particularly to magnetic transfer thereof.

[0002]

2. Description of the Related Art FIG. 9 shows the structure of a general cathode ray tube.
FIG. 10 is a diagram for explaining a conventional magnetic transfer method for a cathode ray tube disclosed in, for example, Japanese Patent Laid-Open No. 62-290034. In the figure, 1 is a face plate panel having a phosphor screen 2, 3 is a color selection electrode provided inside the face plate panel 1, 4 is a frame that supports the color selection electrode, and FIG. 9B shows this frame. As shown in a plan view of the color selection electrode 4 viewed from the direction of the color selection electrode 3, the color selection electrode 3 is supported by the periphery. 5 is an electron gun, 6 is an electron beam, 7 is an internal magnetic shield installed so as to surround the electron beam 6 emitted from the electron gun 5, 8 is joined to the face plate panel 1, the color selection electrode 3, the frame 4 , A funnel that covers the internal magnetic shield 7 and the electron gun 5, 9 is a hole for a color selection electrode, 10 is a landing point of the electron beam 6,
Reference numeral 11 is a twist correction ring coil, which is a color selection electrode 3
Is disposed near the face plate panel 1 of the cathode ray tube. 12 is a spacer, 13 is a DC power supply, 15 is an arrow indicating the tube axis direction, and 17 is a triac.
It is a Degauss coil, and is arranged at a predetermined interval so as to surround the twist correction ring coil 11 around the cathode ray tube. 18 is a triac degauss coil 1
7 power supply.

In a cathode ray tube having such a structure,
The electron beam 6 emitted from the electron gun 5 passes through the hole of the color selection electrode 3 and strikes the phosphor screen 2 at the landing point 10 of the electron beam 6 to emit a desired color. However,
The landing pattern of the electron beam changes in the zero magnetic field state due to mechanical displacement of the color selection electrode 3.
In order to prevent this, in the conventional magnetic transfer of the cathode ray tube,
As shown in FIG. 10, the AC damping magnetic field is applied by the triac degauss coil 18 under the bias magnetic field generated by the twist correction ring coil 11, and the magnetic field generated by the twist correction ring coil 11 is applied to the color selection electrode. Transferred to 3.

[0004]

In the magnetic transfer of the conventional cathode ray tube as described above, the flow of the magnetic field generated from the twist correction ring coil 11 and the triac degauss coil 18 is generated by the coils 11 and 18 together. Since it is arranged in the vicinity of the selection electrode 3 so as to surround the faceplate panel 1 of the cathode ray tube, only a very small part thereof is in the central axis direction, that is, the tube axis direction 15, as shown in FIG. Since the rest of the flow is a curved magnetic field having a curvature, the effective magnetic field component in the tube axis direction 15 is small, and the magnetic field in the tube axis direction 15 is orthogonal to the color selection electrode 3, so the demagnetizing field Due to the action, the magnetic fields generated from the coils 11 and 18 are hardly transferred to the color selection electrode 3 in the tube axis direction 15. Further, since the color selection electrode is usually made of a thin plate material such as low carbon steel of 0.1 mm to 0.2 mm, it is demagnetized by the degaussing magnetic field (Auto Degauss) that acts when the power of the cathode ray tube is turned on, and the magnetic transfer effect disappears. Or there was the problem of a sharp decrease.

Furthermore, since the twist correction ring coil 11 and the triac degauss coil 18 are separate coils to apply the DC bias magnetic field and the AC demagnetizing attenuation magnetic field, the coils 11 and 18 are aligned with each other and A very complicated adjustment such as alignment between the coils 11 and 18 and the cathode ray tube was required.

A first object of the present invention is to effectively perform magnetic transfer to a cathode ray tube and to reliably perform correction even if the landing pattern changes due to mechanical deviation of the color selection electrode 3 or the like, and to land the electron beam 6. It is to prevent mistakes and prevent color misregistration.

The second object of the present invention is to provide a coil 1
The positioning of the coils 1 and 18 becomes unnecessary, and the positioning of the coils 11 and 18 and the cathode ray tube becomes easy.
An object of the present invention is to provide a magnetic transfer device that can easily perform magnetic transfer work.

[0008]

According to a first aspect of the present invention, there is provided a magnetic transfer method for a cathode ray tube, wherein an alternating current having a tube axial component is attenuated under application of a direct current bias magnetic field having a tubular axial component. A magnetic field is applied to magnetically transfer in the tube axis direction to a frame that supports the color selection electrodes of the cathode ray tube in the surroundings.

According to a second aspect of the present invention, there is provided a magnetic transfer device for a cathode ray tube, which comprises first and second coils surrounding a frame for supporting the color selection electrodes of the cathode ray tube at the periphery thereof. In the state in which a bias magnetic field is applied, an alternating attenuating magnetic field is applied by the second coil to magnetically transfer to the frame.

According to a third aspect of the present invention, there is provided a magnetic transfer device for a cathode ray tube, wherein the first and second coils according to the second aspect are both formed on the same frame.

According to a fourth aspect of the present invention, there is provided a magnetic transfer apparatus for a cathode ray tube, wherein the first and second coils according to the second aspect are combined into one coil, and a DC bias magnetic field applied current and an AC demagnetization are applied to this coil. It is configured to pass both currents.

According to a fifth aspect of the present invention, there is provided a magnetic transfer device for a cathode ray tube, wherein the coils according to any one of the second to fourth aspects are arranged at intervals in the tube axial direction of the cathode ray tube. Or a solenoid coil arranged so as to extend in the tube axis direction.

[0013]

In the method of magnetic transfer of a cathode ray tube according to claim 1,
Since a DC bias magnetic field having a tube axis direction component is applied, an AC damping magnetic field having a tube axis direction component is applied to magnetically transfer in the tube axis direction to a frame that supports the color selection electrodes of the cathode ray tube in the surroundings. As the frame has a large dimension in the tube axis direction, it is easy to magnetize in the tube axis direction and hard to erase, and the material can also be easily magnetized, and the landing pattern may change due to mechanical displacement of the color selection electrodes. Can be surely corrected, the landing mistake of the electron beam can be prevented, and the color shift can be prevented.

According to a second aspect of the present invention, there is provided a magnetic transfer device for a cathode ray tube, which comprises first and second coils surrounding a frame for supporting a color selection electrode of the cathode ray tube at a periphery thereof, and a DC bias magnetic field is generated by the first coil. The magnetic transfer method according to claim 1 can be realized by applying an alternating damping magnetic field by the second coil in the applied state to magnetically transfer to the frame. Even if the landing pattern changes, the correction can be surely performed, the landing mistake of the electron beam can be prevented, and the color shift can be prevented.

In the magnetic transfer apparatus for a cathode ray tube according to claim 3, since the first and second coils according to claim 2 are both formed on the same frame, it is not necessary to align the coils with each other. The position of each coil and the cathode ray tube can be easily aligned, and the magnetic transfer work can be facilitated.

In the cathode-ray tube magnetic transfer device according to a fourth aspect of the present invention, one coil serves as both the first and second coils according to the second aspect, and both the DC bias magnetic field applying current and the AC degaussing current are applied to this coil. Since the bias magnetic field and the damping magnetic field can be obtained by one coil, the structure is simplified, the alignment between the coils is not required, and the alignment between the coil and the cathode ray tube is simplified. The magnetic transfer work becomes very easy.

In a cathode ray tube magnetic transfer device according to a fifth aspect of the present invention, the coil according to any one of the second to fourth aspects is
Since it is a plurality of coils arranged at intervals in the tube axis direction of the cathode ray tube or a solenoid coil arranged so as to extend in the tube axis direction, a magnetic field effectively acting in the tube axis direction can be obtained. Therefore, magnetic transfer can be surely performed in the tube axis direction.

[0018]

【Example】

Example 1. FIG. 1 is a cross-sectional configuration diagram for explaining a magnetic transfer method and apparatus for a cathode ray tube according to an embodiment of the present invention as set forth in claims 1, 2 and 5, in which 21 is a frame 4
A first coil that surrounds the vicinity, that is, a coil for applying a DC bias magnetic field, a reference numeral 22 denotes a second coil that surrounds the vicinity of the frame 4, that is, a coil for AC demagnetization. In this embodiment, both coils 21 and 22 are tube axes of a cathode ray tube. 2A and 2B, both coils 21 and 22 have two circular coils with a radius a, which are coaxial and parallel to each other, as shown in FIG. 2B. It shows the case of a Helmholtz coil set equal to a. Two
4a and 4b are frames of the first and second coils 21 and 22, respectively. In the above-described structure, the first coil, that is, the DC bias magnetic field applying coil 21 applies the DC bias magnetic field, and the second coil, that is, the AC degaussing coil 22 applies the AC damping magnetic field to the frame 4 Magnetically transfer to.

The frame 4 has, for example, a thickness of 5 mm and a dimension of 20 mm in the tube axis direction. The frame 4 has a larger dimension in the tube axis direction than the color selecting electrode 3 used for magnetic transfer in the conventional example and is easily magnetized in the tube axis direction. In addition to being difficult to use, it is possible to use a material that is easily magnetized, such as chromium molybdenum steel or martensitic stainless steel, so that even if the landing pattern changes due to mechanical displacement of the color selection electrode 3, it can be reliably corrected. Therefore, the landing mistake of the electron beam 6 can be prevented, and the color shift can be prevented.

Further, as shown in FIG. 2 (b), when two circular coils having a radius of a are coaxially arranged in parallel and the Helmholtz coil has a distance equal to a, a current I is applied to the two coils in the same direction. The magnetic field generated near the center is almost uniform when the magnetic field is applied to the magnetic field, and its strength H is H = 0.716I / a (A / m). Definitely done. This is described in, for example, a publication ("Iwanami Physics and Chemistry Dictionary", 4th edition, page 1187, published in 1992).

In this embodiment, both the DC bias magnetic field applying coil 21 and the AC degaussing coil 22 are composed of a plurality of coils arranged at intervals in the tube axis direction of the cathode ray tube. However, even if only one of the DC bias magnetic field applying coil 21 and the AC degaussing coil 22 has the same effect, there is an advantage that the structure is simplified. Further, even if the pair of coils are not Helmholtz coils arranged at a special interval, they are arranged intensively in the vicinity of the frame 4 even if they are arranged at appropriate intervals in the tube axis direction of the cathode ray tube. Magnetic transfer can be performed more reliably in the tube axis direction than when using one coil. further,
Instead of a plurality of coils arranged at intervals in the tube axis direction of the cathode ray tube, it may be a solenoid coil arranged so as to extend in the tube axis direction, also in this case in the tube axis direction Magnetic transfer is possible without fail.

Example 2. 3 is a sectional view showing a magnetic transfer apparatus for a cathode ray tube according to an embodiment of the present invention. In the drawing, 24 is a coil frame, 25 is a first coil, that is, a DC bias magnetic field applying coil, and 26. Is the second
A coil, that is, an AC degaussing coil, and a DC bias magnetic field applying coil 25 and an AC degaussing coil 26 are formed on the same coil frame 24 to form a magnetic transfer coil 23. In the above-described structure, the second coil, that is, the AC degaussing coil 26 applies an AC damping magnetic field to the frame 4 while the first coil, that is, the DC bias magnetic field applying coil 25 applies the DC bias magnetic field. Magnetically transfer to.

Also in this embodiment, as in the above-mentioned embodiment, the magnetic transfer is carried out to the frame 4 which can be easily magnetized in the tube axis direction and hard to be erased, and can be easily magnetized in terms of material.
Even if the landing pattern changes due to a mechanical shift of the color selection electrode 3 or the like, the landing pattern can be surely corrected, a landing mistake of the electron beam 6 can be prevented, and a color shift can be prevented. Further, in this embodiment, the DC bias magnetic field applying coil 2 is used.
5 and the AC degaussing coil 26 are formed on the same coil frame, the frame 4 is magnetized to perform the magnetic transfer, so that the coils 25 and 26 need not be aligned with each other. Positioning of the coils 25, 26 and the cathode ray tube is also simplified, and the magnetic transfer work is greatly simplified.

Example 3. FIG. 4 is a sectional view showing a magnetic transfer apparatus for a cathode ray tube according to an embodiment of the invention described in claims 3 and 5, and in this example, the DC bias magnetic field applying coil 25 and the AC degaussing coil 26 are in the same coil frame. Magnetic transfer coils 23 formed on 24 are arranged at a predetermined interval in the tube axis direction of the cathode ray tube to form a pair of Helmholtz coils. In the thus configured device, the AC degaussing coil 26 is applied in a state in which the DC bias magnetic field is applied by the DC bias magnetic field applying coil 25.
The magnetic field is transferred to the frame 4 by applying an alternating magnetic field.

In this embodiment, the magnetic transfer can be surely performed as in the case of the second embodiment, and the magnetic transfer work becomes very simple. Further, since the Helmholtz type magnetic transfer coil 23 is used in this embodiment, there is an advantage that the magnetic transfer in the tube axis direction can be performed more reliably as in the first embodiment.

As in the case of the first embodiment, even if the pair of coils are not Helmholtz coils arranged at special intervals, they are arranged at appropriate intervals in the tube axis direction of the cathode ray tube. Even in such a case, magnetic transfer can be surely performed in the tube axis direction rather than using one coil concentratedly arranged in the vicinity of the frame 4.

Example 4. FIG. 5 is a sectional view showing a magnetic transfer device for a cathode ray tube according to another embodiment of the present invention. In this example, the DC bias magnetic field applying coil 25 and the AC degaussing coil 26 are the same. Coil frame 2
The magnetic transfer coil 23 formed on the upper part 4 is arranged so as to extend in the tube axis direction of the cathode ray tube and constitutes a solenoid coil. In the one configured in this way,
First coil, ie, DC bias magnetic field applying coil 25
With a DC bias magnetic field applied, a second coil, that is, an AC degaussing coil 26 applies an AC damping magnetic field to magnetically transfer to the frame 4.

Also in this embodiment, the magnetic transfer can be surely performed as in the case of the second embodiment, and the magnetic transfer work becomes very simple. Further, since the solenoid type magnetic transfer coil 23 is used in this embodiment, most of the magnetic field distribution in the coil is in the central axis direction as shown in FIG. The advantage is that magnetic transfer can be performed.

Example 5. FIG. 6 is a sectional view showing a magnetic transfer apparatus for a cathode ray tube according to an embodiment of the present invention. In FIG. 6, reference numeral 27 is a magnetic transfer coil for passing both a DC bias magnetic field applying current and an AC degaussing current at the same time. Is. In such a configuration, in the state where both the DC bias magnetic field applying current and the AC degaussing current are simultaneously applied to the magnetic transfer coil 27 and the DC bias magnetic field is applied,
An AC damping magnetic field is applied to magnetically transfer to the frame 4.

In this embodiment, the magnetic transfer can be surely performed as in the case of the second embodiment, and the magnetic transfer work becomes very simple. Further, in this embodiment, the bias magnetic field and the damping magnetic field are obtained by one coil 27, and the number of parts is reduced, and the structure is simplified.

Example 6. FIG. 7 is a cross-sectional view showing a magnetic transfer device for a cathode ray tube according to an embodiment of the present invention, and in this example, a magnetic transfer coil in which both a DC bias magnetic field applying current and an AC degaussing current are made to flow simultaneously. 27
Are arranged at a predetermined interval in the tube axis direction of the cathode ray tube to form a pair of Helmholtz coils.

Also in this embodiment, the magnetic transfer can be surely performed as in the case of the fifth embodiment, the magnetic transfer work and the structure are simplified, and the Helmholtz coil can surely perform the magnetic transfer in the tube axial direction.

Even if the pair of coils are not Helmholtz coils arranged at special intervals, even if they are arranged at appropriate intervals in the tube axis direction of the cathode ray tube, they are concentrated near the frame 4. As in the case of the first and third embodiments, magnetic transfer can be performed more reliably in the tube axis direction than by using one coil arranged.

Example 7. FIG. 8 is a sectional view showing a magnetic transfer device for a cathode ray tube according to another embodiment of the present invention. In this example, a DC bias magnetic field applying current and an AC degaussing current both flow at the same time. Coil 2
A solenoid coil 7 is arranged so as to extend in the tube axis direction of the cathode ray tube.

Also in this embodiment, the magnetic transfer can be surely performed as in the case of the fifth embodiment, the magnetic transfer work and the structure are simplified, and the magnetic transfer can be surely performed in the axial direction of the tube by the solenoid coil.

[0036]

As described above, according to the first aspect of the present invention, in the state where the DC bias magnetic field having the tube axial direction component is applied, the AC damping magnetic field having the tube axial direction component is applied to the cathode ray. Since the color selection electrodes of the tubes are magnetically transferred in the tube axis direction to the frame that supports the surroundings, the frame has a large dimension in the tube axis direction, is easily magnetized in the tube axis direction, is hard to disappear, and is also easily materialized. Even if the landing pattern changes due to mechanical displacement of the color selection electrodes, it is possible to surely correct the landing pattern, prevent landing mistakes of the electron beam, and prevent color misregistration.

According to the second aspect of the present invention, there are provided first and second coils surrounding the vicinity of the frame for supporting the color selection electrodes of the cathode ray tube on the periphery thereof, and a DC bias magnetic field is applied by the first coil. The magnetic transfer method according to claim 1 can be realized because an alternating damping magnetic field is applied by the second coil to magnetically transfer to the frame, and the landing pattern is changed due to mechanical deviation of the color selection electrodes. Even if it changes, it can be surely corrected, the landing mistake of the electron beam can be prevented, and the color shift can be prevented.

According to the invention described in claim 3, since the first and second coils according to claim 2 are both formed on the same frame, it becomes unnecessary to align the coils with each other and Positioning with the cathode ray tube becomes easy,
Magnetic transfer work becomes easy.

According to the invention described in claim 4, one coil serves as both the first and second coils described in claim 2, and both the DC bias magnetic field applying current and the AC degaussing current are made to flow through this coil. Since the bias magnetic field and the damping magnetic field are obtained by one coil, the structure is simplified, and the coils are not required to be aligned with each other, and the alignment between the coils and the cathode ray tube is also facilitated. Becomes very easy.

According to the invention described in claim 5, the coil according to any one of claims 2 to 4 is a plurality of coils arranged at intervals in the tube axis direction of the cathode ray tube or the tube axis. Since the solenoid coil is arranged so as to extend in the direction, a magnetic field that effectively acts in the tube axis direction can be obtained, and magnetic transfer can be reliably performed in the tube axis direction.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram illustrating a magnetic transfer method and apparatus for a cathode ray tube according to a first embodiment.

FIG. 2 is an explanatory diagram showing a difference in magnetic field distribution depending on a coil configuration.

FIG. 3 is a sectional configuration diagram showing a magnetic transfer device for a cathode ray tube according to a second embodiment.

FIG. 4 is a sectional configuration diagram showing a magnetic transfer device for a cathode ray tube according to a third embodiment.

FIG. 5 is a sectional configuration diagram showing a magnetic transfer device for a cathode ray tube according to a fourth embodiment.

FIG. 6 is a sectional configuration diagram showing a magnetic transfer device for a cathode ray tube according to a fifth embodiment.

FIG. 7 is a sectional configuration diagram showing a magnetic transfer device for a cathode ray tube according to a sixth embodiment.

FIG. 8 is a sectional configuration diagram showing a magnetic transfer device for a cathode ray tube according to a seventh embodiment.

9A and 9B show a structure of a general cathode ray tube, FIG. 9A is a cross-sectional view, and FIG. 9B is a plan view of a frame as viewed from a direction of a color selection electrode.

FIG. 10 is an explanatory diagram showing a state of magnetic transfer in a conventional cathode ray tube device.

[Explanation of symbols]

 1 Face plate panel 2 Fluorescent screen 3 Color selection electrode 4 Frame 5 Electron gun 6 Electron beam 10 Landing point 11 Twist correction ring coil 12 Spacer 17 Triac Degauss coil 21, 25 DC bias magnetic field applying coil 22, 26 For AC degaussing Coil 23 Magnetic transfer coil 24, 24a, 24b Coil frame 27 Magnetic transfer coil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Tanabe 8-1-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Corporation Material Device Research Center (72) Inventor Yoshihiro Tani 8-1-1 Tsukaguchihonmachi, Amagasaki Mitsubishi Electric Device Co., Ltd. Material Device Research Center

Claims (5)

[Claims] 1. A DC bias magnetic field having a tube axial direction component is applied, and an AC damping magnetic field having a tube axial direction component is applied to the frame for supporting the color selection electrodes of the cathode ray tube in the tube axial direction. A magnetic transfer method for a cathode ray tube, characterized in that magnetic transfer is performed on the cathode. 2. A first and a second coil surrounding the vicinity of a frame for supporting the color selection electrode of the cathode ray tube on the periphery thereof, wherein a DC bias magnetic field is applied by the first coil,
A magnetic transfer apparatus for a cathode ray tube, characterized in that an AC damping magnetic field is applied by the second coil to magnetically transfer to the frame. 3. The magnetic transfer device for a cathode ray tube according to claim 2, wherein the first and second coils are both formed on the same frame. 4. The cathode wire according to claim 2, wherein one coil serves as the first coil and the second coil, and both of the DC bias magnetic field applying current and the AC degaussing current are caused to flow through the coil. Tube magnetic transfer device. 5. The coil is a plurality of coils arranged at intervals in the tube axis direction of the cathode ray tube or a solenoid coil arranged so as to extend in the tube axis direction. A magnetic transfer device for a cathode ray tube according to claim 2.