JP2000243314A - Electron beam deflecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the electric power required for deflecting electron beams by arranging a horizontal deflection yoke and a vertical deflection yoke at different positions in the longitudinal direction. SOLUTION: A horizontal deflection yoke 1 is arranged on the side of an electron gun 105 of a neck section 102, and a vertical deflection yoke 2 is arranged on the side of a front panel 103 separately from each other in this electron beam deflecting device. Three electron beams emitted from the electron gun 105 for displaying red, green and blue are horizontally applied with Lorentz' s force by the horizontal deflection yoke 1 arranged on the side of the electron gun 105, are vertically applied with Lorentz's force by the vertical deflection yoke 2 arranged on the side of the front panel 103, and are scanned two- dimensionally. The horizontal deflection yoke 1 is composed of a flat and annular deflection core and a pair of deflection coils and has two magnetic poles facing each other in a void space where the electron beams pass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam deflecting apparatus for scanning a front panel by deflecting an electron beam emitted from an electron gun in a cathode ray tube.

[0002]

2. Description of the Related Art A cathode ray tube conventionally used as a display device has an electron gun and a front panel facing the electron gun. And this cathode ray tube
The electron beam emitted from the hot cathode in the electron gun is accelerated and converged by an electrode group provided in the electron gun, and converges and collides on a phosphor screen applied to the front panel. At this time, visible light emitted from the phosphor is emitted. To display image information.

[0003] In a cathode ray tube for performing color display, three electron guns or one electron gun having three hot cathodes are used.
Three electron beams converge and collide with the phosphor screen on which phosphors for red, green, and blue are arranged to generate red, green, and blue light,
Color display is performed by additive color mixture. In this case, an opening such as a slit or a circle corresponds to a pixel on the electron gun side several hundred microns from the phosphor screen so that the three electron beams selectively collide with the phosphors for each of red, green and blue. A large number of color selection mechanisms are provided.

Since the image information has a two-dimensional spread, it is displayed by scanning the electron beam two-dimensionally on the phosphor screen. The cathode ray tube is provided with an electron beam deflecting device that generates a magnetic field or an electric field near the end of the electron gun in order to scan the electron beam. A device for deflecting an electron beam by a magnetic field is called a deflection yoke, and includes a horizontal deflection yoke having a horizontal deflection coil and a vertical deflection yoke having a vertical deflection coil. These horizontal deflection coils and vertical deflection coils generate magnetic fields orthogonal to each other. By changing the current flowing through each of these coils, the electron beam converged on the phosphor screen scans the phosphor screen two-dimensionally. The horizontal deflection coil and the vertical deflection coil have a laminated structure together with the deflection core.

[0005] The deflection yoke is disposed on the rear side of the cathode ray tube from a portion called a neck containing the electron gun to an outside of a portion called a funnel extending in a cone shape from the tip of the electron gun toward the front panel. The neck portion is cylindrical, and the funnel portion following this neck portion expands in a cone shape, so that the deflection yoke conforms to the outer shape of these neck portion and funnel portion.
The inner surface has a cone shape following a cylindrical shape.

[0006]

In the electron beam deflecting device as described above, the electron beam passes from the neck toward the funnel. In the neck portion and the funnel portion, the strength of the magnetic field formed by the deflection yoke is proportional to the reciprocal of the distance if the current supplied to the deflection coil is constant according to Ampere's law. Therefore, the smaller the diameter of the neck portion, the stronger the deflection magnetic field received by the electron beam in the neck portion, and the smaller the power required for deflection. However, when the diameter of the neck portion is reduced, the outer shape of the electron gun that can be mounted on the neck portion must be reduced. As a result, the diameter of the electron lens of the electron gun decreases, and aberration increases. When the aberration in the electron lens increases, the spot diameter of the electron beam on the phosphor screen increases, and the resolution of the displayed image deteriorates.

As described above, the power consumption of the deflection yoke and the image forming ability of the electron beam are in conflicting characteristics, and
In order to maintain a predetermined imaging capability, the diameter of the neck portion is φ
The limit of diameter reduction is up to about 22 mm, and there has been a problem that it is difficult to increase the efficiency of deflection power with a conventional deflection yoke.

The deflection power, specifically, the square product L of the inductance L of the deflection yoke and the current i supplied to the deflection yoke
Technologies that have improved i2 include “KKN Chang,“ An Exp
erimental “In-Neck” Integrated Yoke ”, SID84 Digest,
As described in P264 (Document [1]), there is a type in which a deflection yoke is built in a neck portion. This technique is intended to reduce the inner diameter of the deflection yoke and increase the deflection power by being incorporated in the neck portion.

[0009] However, the inner wall of the neck is 20 kV.
Since the pressure is high as described above, if the deflection coil is made of a conventional enameled wire, insulation becomes a problem. For this reason, the above-mentioned document [1] proposes to use a polyimide-based resin for covering a conductor constituting a deflection coil. However, the polyimide resin is not only very expensive, but also pollutes the inside of the cathode ray tube by outgassing,
There is a problem that a problem such as electric discharge occurs and the life of the cathode ray tube is deteriorated. Further, when the deflection yoke is incorporated in the neck portion, it is extremely difficult to adjust the arrangement position of the deflection yoke and the magnetic field correction from the outside of the cathode ray tube, which is not practical.

[0010] Also, the document "Y. Sano etc," A High-Deflec
tion-sensitivity CDT with Reefangular Yoke ", SID98
Digest, P85 ”(reference [2]) states that the deflection yoke is squared in accordance with the vertical and horizontal deflection angles, and the neck is squared in accordance with this. A technique of forming a groove for winding a coil has been proposed. In this configuration, the coupling between the magnetic field generated from the deflection coil and the core is strengthened, and the deflection power can be reduced.

However, in this technique, although the space in which the deflecting magnetic field is generated is smaller than in the prior art, the space for deflecting the electron beam is the same as in the prior art. Is reduced by only about 23%. In addition, since the distribution of the coils for adjusting the convergence is determined by the grooves on the inner wall of the core having strong magnetic coupling, the manufacturing accuracy of the grooves must be increased, which causes a problem in manufacturing and cost.

Accordingly, the present invention has been proposed in view of the above situation, and aims to reduce the power required to deflect an electron beam without causing problems in manufacturing and cost. It is an object of the present invention to provide an electron beam deflecting device capable of performing the above.

[0013]

An electron beam deflecting device according to the present invention deflects an electron beam emitted forward from an electron gun disposed in a rear neck portion of a cathode ray tube in a horizontal direction. An electron beam deflecting device, comprising a deflection yoke for horizontal deflection and a deflection yoke for vertical deflection for deflecting the electron beam in a vertical direction, for scanning the electron beam two-dimensionally on a front panel, In order to solve the above problem, the deflection yoke for horizontal deflection and the deflection yoke in the vertical direction are arranged at different positions in the front-rear direction. At least one of the deflection yoke for horizontal deflection and the deflection yoke for vertical deflection includes a magnetic core having an opposite magnetic pole provided with a gap through which an electron beam passes.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

The present invention provides an electron beam deflecting device capable of greatly reducing deflection power as compared with a conventional deflection yoke.

FIG. 1 shows an electron beam deflection apparatus according to the present invention.
As shown in (1), it is attached to the outer surface of the tube 101 of the cathode ray tube to constitute a part of the cathode ray tube. The tube 101 of the cathode ray tube has a substantially cylindrical neck portion 102 at a rear portion and a substantially rectangular flat front panel 103 at a front portion. The neck portion 102 and the front panel 103 are connected to the neck portion 10.
They are connected via a funnel portion 103 which is formed in a conical shape and is continuously provided with the diameter increased in the forward direction from 1.

An electron gun 105 is built in the neck 102. The electron gun 105 emits three electron beams for red display, green display, and blue display from the hot cathode toward the front side. These electron beams are accelerated and converged by an electrode group provided in the electron gun, and the front panel 1
03 converges and collides on a phosphor screen formed by applying a phosphor on the back surface. In this way, when the electron beam collides with a predetermined portion of the phosphor screen, visible light of a predetermined color is emitted from the phosphor forming the phosphor screen, and image information is displayed. Further, a color selection mechanism (not shown) in which a large number of slits or circular openings are provided in accordance with the pixels at a position several hundred microns away from the phosphor screen on the electron gun 105 side.

The electron beam deflecting device is configured such that the horizontal deflection yoke 1 and the vertical deflection yoke 2 are separately disposed on the electron gun 105 side and the front panel 103 side of the neck portion 102, respectively. In this electron beam deflecting device, as shown in FIG. 2, three electron beams emitted from the electron gun 105 for red display, green display, and blue display are:
The horizontal deflection yoke 1 disposed on the side of the electron gun 105 receives the Lorentz force in the horizontal direction, and then the front panel 103
The scanning is performed two-dimensionally by receiving the Lorentz force in the vertical direction by the vertical deflection yoke 2 arranged on the side.

The horizontal deflection yoke 1 is, as shown in FIG.
Flat annular deflection core 3 fitted in neck 102
And a pair of deflection coils 4 and 4. On the inner edge of the deflecting core 3, coil winding portions 5, 5 opposing each other are protruded. These coil winding parts 5, 5
The deflection coils 4 and 4 are wound around the outer peripheral surface, so that the tip becomes a magnetic pole. The direction in which the coil winding portions 5 and 5 face each other is the minor diameter direction of the deflection core 3. The through hole at the center of the deflecting core 3 becomes a void space through which the electron beam passes. Therefore, the deflection core 3 has a structure having two magnetic poles facing each other in a gap space through which an electron beam passes.

Although the overall size of the vertical deflection yoke 2 is larger than that of the horizontal deflection yoke 1, the vertical deflection yoke 2 has substantially the same configuration as the horizontal deflection yoke 1. However, in the vertical deflection yoke 2, the opposing magnetic pole is arranged at a position rotated by 90 degrees with respect to the position of the opposing magnetic pole of the horizontal deflection yoke 1, that is, the direction in which the coil winding portions oppose each other is determined by It is in the major axis direction. In the horizontal deflection yoke 2, since the frequency is high, the reduction in deflection power is more important than in the vertical deflection yoke 1.

The neck portion 102 of the cathode ray tube has a horizontally long flat shape in accordance with the gap between the opposing magnetic poles of each deflection core, as shown in FIG.

Here, the deflection core of the electron beam deflecting device according to the present invention will be compared with the deflection yoke of the conventional electron beam deflecting device. A deflection yoke of a conventional electron beam deflection device has an annular deflection core 106 as shown in FIG. Since the deflection core 106 is annular, the inner diameter L is substantially equal to the outer diameter of the cylindrical neck in any direction. On the other hand, in the deflection yoke of the electron beam deflecting device according to the present invention, as shown in FIG. 5, the width (length in a direction orthogonal to the direction between the magnetic poles) L ′ of the coil winding portion 5 is the same as the conventional one. And the distance Lg between the magnetic poles is not more than half of the inner diameter L. As described above, the space where the deflection magnetic field acting on the electron beam is generated is made narrower because of the opposed magnetic pole structures. Therefore,
In the deflection yoke using the deflection core 3, the space having a high magnetic resistance is reduced, the entire core can be reduced, the magnetic path length is reduced, and the magnetic resistance is reduced. It is possible to generate a magnetic field twice or more. Furthermore, in this deflection yoke, since the magnetic path is smaller than that of the conventional deflection yoke, the inductance can be reduced.

The electron beam deflecting device according to the present invention is
As a result of measurement by mounting the device on an inch-size cathode ray tube, it was possible to reduce the deflection power to half for the same deflection angle as compared with the case where a conventional deflection yoke was used.

As shown in FIG. 6, the electron beam deflecting device according to the present invention uses a horizontal deflection yoke 1 having the same structure as that of the above-described embodiment, and a vertical deflection yoke 2 as shown in FIG. It is also possible to use a cylindrical vertical deflection core 6 having a structure in which a plurality of vertical deflection coils 7 are formed by toroidally winding the outer peripheral surface of the vertical deflection core 6. When the vertical deflection yoke 2 having this structure is used, the electron beam subjected to horizontal deflection receives the vertical deflection magnetic field inside the cylindrical vertical deflection core 6 having a wide deflection space, so that the deflection angle can be increased. The advantage is that convergence can be easily adjusted.

Further, in the electron beam deflecting device according to the present invention, as shown in FIG. 7, a horizontal deflection yoke 1 having the same structure as that of the above-described embodiment is used.
As the vertical deflection yoke 2, a vertical deflection core 8 having a rectangular frame shape and having a plurality of vertical deflection coils 7 formed by applying a toroidal winding to the outer surface of the vertical deflection core 8 may be used. . In the case of using the vertical deflection yoke 2 having this structure, the electron beam subjected to horizontal deflection receives a vertical deflection magnetic field inside the rectangular frame-shaped vertical deflection core 8 having a wide deflection space, so that the deflection angle can be increased. The advantage is that convergence can be easily adjusted. Further, in this case, the size of the vertical deflection yoke 2 can be reduced, and the magnetic path length can be reduced, so that the deflection power of the vertical deflection yoke can be reduced as compared with the case where the cylindrical vertical deflection core 6 is provided. Note that this rectangular frame-shaped vertical deflection core 8 is
It may have a square cone shape (pyramid shape) that extends from the horizontal deflection yoke 1 side to the front panel 103 side.

[0026]

As described above, in the electron beam deflecting device according to the present invention, the deflection power required to deflect the electron beam can be greatly reduced. In particular, the deflection power of the horizontal deflection yoke, which has a high frequency and causes an increase in deflection power, can be significantly reduced.

In this electron beam deflector, the size of the deflection yoke can be reduced and the inductance can be reduced, so that the frequency characteristics can be improved. In particular, for horizontal deflection, the deflection frequency may be 100 kHz or more. Therefore, reducing the inductance of the driver circuit enables reduction in driving load and power consumption.

Further, in this electron beam deflecting device, the horizontal deflection yoke and the vertical deflection yoke are independent of each other, and the deflection cores are also independent of each other. Therefore, the characteristics of the deflection core, that is, magnetic permeability, core loss, saturation magnetic flux Each deflection yoke, including the density and the like, can be designed independently, and optimization of each deflection yoke is easy.

That is, the present invention can provide an electron beam deflecting device capable of reducing the power required to deflect an electron beam without causing problems in manufacturing and cost. is there.

[Brief description of the drawings]

FIG. 1 is a horizontal cross-sectional view, a partial vertical cross-sectional view, and a main part vertical cross-sectional view illustrating a configuration of a cathode ray tube to which an electron beam deflector according to the present invention is applied.

FIG. 2 is a side view showing an electron beam deflecting operation in the electron beam deflecting device.

FIG. 3 is a front view and a side view showing a configuration of a deflection yoke of the electron beam deflector.

FIG. 4 is a front view of a conventional deflection yoke shown for comparison with a deflection yoke of the electron beam deflector.

FIG. 5 is a longitudinal sectional view showing a configuration of the electron beam deflecting device.

FIG. 6 is a main part perspective view showing another embodiment of the configuration of the electron beam deflector.

FIG. 7 is a main part perspective view showing still another embodiment of the configuration of the electron beam deflector.

[Explanation of symbols]

Reference Signs List 1 horizontal deflection yoke, 2 vertical deflection yoke, 3 deflection core, 4 deflection coil, 5 coil winding part, 6, 8 vertical deflection core, 7 vertical deflection coil, 101 tube, 1
02 neck, 103 front panel, 104 funnel, 105 electron gun

Claims (6)

[Claims] 1. A horizontal deflection deflection yoke for horizontally deflecting an electron beam emitted forward from an electron gun disposed in a rear neck portion of a cathode ray tube, and deflecting the electron beam in a vertical direction. And a deflection yoke for vertically deflecting the electron beam.
An electron beam deflecting device for scanning in a three-dimensional manner, wherein a deflection yoke for horizontal deflection and a deflection yoke for vertical direction are arranged at mutually different positions in the front-back direction. Deflection device. 2. A deflection yoke for horizontal deflection and a deflection yoke for vertical deflection include a magnetic core having an opposing magnetic pole provided with a gap through which an electron beam passes. Electron beam deflector for cathode ray tube. 3. The deflection yoke for horizontal deflection and the deflection yoke for vertical deflection have a space through which the electron beam can pass if the magnetic core does not have an opposing magnetic pole provided with a gap through which the electron beam passes. 3. An electron beam deflector for a cathode ray tube according to claim 2, further comprising a cone-shaped magnetic core. 4. The electron beam deflector for a cathode ray tube according to claim 3, wherein the cone-shaped magnetic core has a shape of a circle, a square, or a combination of a circle and a square. . 5. A deflection yoke provided with a magnetic core having opposed magnetic poles provided with a gap through which an electron beam passes, wherein the deflection yoke is formed by forming at least a part of a neck portion of a cathode ray tube into a flat shape. 3. The electron beam deflector for a cathode ray tube according to claim 2, wherein the electron beam deflector is mounted on a part. 6. The deflection yoke for horizontal deflection and the deflection yoke for vertical deflection have a space through which the electron beam can pass if the magnetic core does not have an opposing magnetic pole provided with a gap through which the electron beam passes. 6. An electron beam for a cathode ray tube according to claim 5, wherein the electron beam has a cone-shaped magnetic core, and the cone-shaped magnetic core has a shape of a circle, a square, or a combination of a circle and a square. Deflection device.