JP3279328B2 - Cathode ray tube image display - Google Patents

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 image display device for TV and business use, and more particularly to a means for reducing unnecessary radiation generated from a deflection yoke used in the image display device.

[0002]

2. Description of the Related Art Deflection yokes, flyback transformers, and other coils are sources of unwanted radiation in TVs and professional video display devices.
The main source among them is the deflection yoke. Various means have been proposed for reducing unnecessary radiation generated from the deflection yoke, one example of which is disclosed in Japanese Patent Application Laid-Open No. 62-826.
No. 33 discloses this. This eliminates unnecessary radiation generated from fringes at the front end (the end of the cathode ray tube on the panel side) and the rear end (the end of the cathode ray tube on the neck side) of the horizontal deflection coil.

[0003] More specifically, a clad coil substantially similar to a horizontal deflection coil, this cancellation coil is connected in series to the horizontal deflection coil, and the magnetic flux generated at the front end and the rear end fringe of the cancellation coil. This cancels the magnetic flux generated from the fringes at the front end and the rear end of the horizontal deflection coil, that is, unnecessary radiation.

[0004]

The above prior art requires the winding of the canceling coil and the mounting of the wound coil, and the connection of the coil to the horizontal deflection coil, and these operations are added. Naturally, the cost of the members also increases, and the cost of the deflection yoke increases. In addition, there is a problem that a stable characteristic cannot be obtained because a variation in the canceling effect occurs due to the variation in the mounting state.

The present invention solves the above-mentioned drawbacks of the conventional device,
It is an object of the present invention to provide a cathode ray tube image display device capable of reducing unnecessary radiation while reducing cost.

[0006]

In order to achieve the above object, the present invention does not use a wound canceling coil or the like, but simply employs a horizontal deflection coil and a vertical deflection coil at the opening side and at the neck, respectively. By tilting the side fringe shape, a deflection yoke with stable characteristics is provided.

[0007]

When a deflection current flows through the horizontal deflection coil, the direction of the main magnetic flux for deflecting the electron beam emitted from the cathode ray tube to the left / right direction, the fringe portion on the opening side of the horizontal deflection coil and the neck portion side The directions of the magnetic flux generated from the fringe portion are opposite to each other. However, very low frequency magnetic fields (VLM
Unnecessary radiation in F) is dominated by the main magnetic flux. Unnecessary radiation can be reduced by weakening the main magnetic flux.
Therefore, in order to weaken the main magnetic flux, it is sufficient to increase the magnetic flux which is opposite to the main magnetic flux and which emerges from the fringe portions on the opening side and the network side.

Similarly, when a deflection current flows through the vertical deflection coil, the direction of the main magnetic flux for deflecting the electron beam in the up / down direction and the fringe portion and the neck portion on the opening side of the vertical deflection coil are determined. The directions of the magnetic flux generated from the fringe portion are opposite to each other. The unnecessary radiation of the extremely low frequency magnetic field (ELMF) is dominated by the main magnetic flux. If the main magnetic flux is weakened, the unnecessary radiation is reduced, and at the same time, the extremely low frequency magnetic field (RF) due to the high frequency component flowing through the vertical deflection coil is reduced. ULM
Unnecessary radiation of F) is also reduced.

[0009]

An embodiment of the present invention will be described below. FIG. 1 is a schematic side view of the deflection yoke. In FIG.
Is a horizontal deflection coil, 2 and 2 'are vertical deflection coils, and 3 is a magnetic core. In this deflection yoke, the magnetic flux emitted from the horizontal deflection coils 1 and 1 'is as shown in FIG.

In FIG. 2, the magnetic flux measured as unnecessary radiation of the very low frequency magnetic field of the deflection yoke includes a main magnetic flux 4 for deflecting the electron beam emitted from the cathode ray tube to left / right directions.
4 'is dominant. However, this horizontal deflection coil 1,
The magnetic fluxes 6, 6 'emitted from the fringe portions 5, 5' on the opening side of 1 'and the fringe portions 7, 7' on the neck side are magnetic fluxes in the direction opposite to the direction of the main magnetic flux. Therefore, if the reverse magnetic flux coming out of the fringe portion is strengthened, the main magnetic flux can be weakened, and unnecessary radiation can be reduced.

Therefore, as shown in FIG. 3, the fringe portions 5, 5 'on the opening side of the horizontal deflection coils 1, 1' are inclined to the funnel side of the cathode ray tube, and the fringe portions 7, 7 'on the neck side are connected. If it is inclined in the opposite direction to the funnel side, the magnetic fluxes 6, 6 'from these fringe portions are weakened, the effect of canceling the main magnetic fluxes 4, 4' is increased, and unnecessary radiation is reduced. Further, in order to enhance or weaken the canceling effect, the inclination angle θ ₁ of the fringe portion with respect to the axis ZZ,
It is sufficient to change θ ₁ ′ and θ ₂ , θ ₂ ′.

According to the experimental results, θ₁ , Θ₁ '> Θ_Two ,
θ_Two 'Gives better results and θ ₁ , Θ₁ ′ Is 45 °
~ 70 °, θ_Two , Θ_Two 'Is the smallest when it is 15 ° to 25 °
It was the unnecessary radiation value. In addition, these angles θ₁ , Θ
₁ ', Θ_Two , Θ_Two 'Is a TV set or commercial video
A deflection yoke and a cathode ray tube are assembled in the display unit.
Is necessarily necessarily θ₁ = Θ₁ ', Θ_Two = Θ
_Two ′, There is no need to₁ ≠ θ₁ ', Θ_Two ≠ θ_Two ′
It was also confirmed that in the case of, the minimum unnecessary radiation value was obtained.

Similarly, a very low frequency magnetic field and a very low frequency magnetic field are generated as unnecessary radiation from the vertical deflection coil.
One embodiment of a countermeasure for this is shown in FIG. FIG. 4 is a side view of FIG. 3 viewed from above, that is, FIG. 3 is a view obtained by rotating FIG. 3 by 90 °. The magnetic fluxes generated by the vertical deflection coils 8, 8 'are combined with main magnetic fluxes 9, 9' for deflecting the electron beam emitted from the cathode ray tube upward / downward and the vertical deflection coils 8, 8 '.
The magnetic fluxes 10, 1 emerging from the fringe portions 11, 11 'on the opening side of 8' and the fringe portions 12, 12 'on the side of the neck portion
0's are in opposite directions.

Therefore, the fringe portions 11, 11 'and 12, 12' on the opening side and the neck side of the vertical deflection coil.
In the same manner as the horizontal deflection coil,
1,11 'The Fuan'neru side theta _3, theta _3' inclined, it is possible to reduce unwanted radiation by tilting 'theta _4, theta ₄ a in the direction opposite to Fuan'neru side' fringe portion 12, 12 of the take root portion . This inclination angle is also θ ₃ , θ ₃ ′> θ ₄ ,
θ ₄ ′ is more effective.

[0015]

As described above, according to the present invention, as compared with the conventional apparatus for mounting the wound canceling coil, the number of man-hours and member costs for producing the deflection yoke are greatly reduced, and the cost is greatly reduced. Can be reduced. In addition, since there is no attachment of the canceling coil or the like, there is no variation in characteristics due to the attachment, so that the characteristics of the deflection yoke are stabilized.

Further, since a canceling coil is attached and connected to the horizontal deflection coil in series or parallel,
This canceling coil becomes a loss when viewed from the horizontal deflection circuit, and it is inevitable that the horizontal deflection efficiency is reduced. However, according to the present invention, the reduction of the horizontal deflection efficiency is almost negligible, and the circuit constant is reduced. No changes are required.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a deflection yoke according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a direction of a magnetic flux generated from a horizontal deflection coil of the deflection yoke.

FIG. 3 is an explanatory diagram of a horizontal deflection coil according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a vertical deflection coil according to the embodiment of the present invention.

[Description of Signs] 1,1 'horizontal deflection coil 2, 2' vertical deflection coil 3 core 4, 4 'main magnetic flux of horizontal deflection coil 5, 5' opening side fringe portion of horizontal deflection coil 6, 6 'horizontal deflection fringe portion flux 7,7 'take root portion side fringe portions theta ₁ of the horizontal deflection coil, theta _1' of coil tilt angle theta ₂ of the opening side fringe portion of the horizontal deflection coil, theta ₂ 'take root side fringe of the horizontal deflection coil 8,8 'Vertical deflection coil 9,9' Main magnetic flux of vertical deflection coil 10,10 'Fringe magnetic flux of vertical deflection coil 11,11' Fringe portion 12,12 'on opening side of vertical deflection coil Fringes at the neck of the vertical deflection coil θ ₃ , θ ₃ ′ Tilt angles of the fringes at the opening of the vertical deflection coil θ ₄ , θ ₄ ′ Tilt angles of the fringes at the neck of the vertical deflection coil

Continuation of the front page (56) References JP-A-3-112038 (JP, A) JP-A-3-145042 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 29 / 76 H04N 3/16 H04N 9/29

Claims (1)

(57) [Claims] 1. A cathode ray tube image display device comprising a saddle-saddle-type deflection yoke in which a pair of clad-type horizontal deflection coils and a pair of clad-type vertical deflection coils are disposed inside a wrapper-shaped core. The fringe portion on the opening side of the deflection coil is tilted toward the funnel side of the cathode ray tube, and the fringe portion on the net portion side is tilted in the direction opposite to the funnel side of the cathode ray tube. Similarly, the fringe portion on the opening side of the vertical deflection coil is shifted toward the cathode ray tube. A cathode ray tube image display device characterized in that the cathode ray tube is tilted toward the funnel side and the fringe portion on the neck side is tilted in the direction opposite to the funnel side of the cathode ray tube.