JPS63294655A - Deflection yoke - Google Patents

Abstract

PURPOSE:To obtain a good image screen including no distortion by changing the length of each of upper and lower horizontal coils to change the deflection sensitivity or changing the winding numbers of the same to change the inductance for those coils. CONSTITUTION:The deflection sensitivity of the lower side horizontal coil 3 is increased by setting its length larger than the length of the upper side horizontal coil 2. In the upper and lower horizontal coils connected in parallel to each other, electric current iB flowing through the lower horizontal coil 3 is increased (iB>iA) by setting the inductance LB of the lower horizontal coil 3 smaller than the inductance LA of the upper horizontal coil 2. A good image screen free of distortion can be obtained in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a deflection yoke used in a cathode ray tube called a flat tube.

[Background of the invention]

In the conventional deflection yoke, the upper and lower horizontal coils had the same length, the same number of turns, and the same inductance, so naturally they had the same deflection force. For this reason, in vertically asymmetrical cathode ray tubes such as flat tubes, vertically asymmetrical screen distortion occurs, and this is corrected by a circuit, which is very expensive. Incidentally, related devices of this type include, for example, Japanese Patent Laid-Open No. 60-81743, but this society's known law deals with landing correction.

The prior art will be specifically explained below.

FIG. 3 shows the perspective view of the above-mentioned flat tube. In the same figure,
1 shows the screen of a flat tube.

FIG. 4(a) is a front view of a conventional deflection yoke, and FIG. 4(b) is a side view of the same. In these figures, 2 is an upper horizontal coil, 3 is a lower horizontal coil, and 4 is a magnetic piece.

FIG. 5(a) shows a good screen without distortion, and FIG. 5(b) shows a flat screen with distortion.

Now, in the case of flat quality as shown in Figure 3, Figure 4 especially
In a deflection yoke with a vertically balanced horizontal coil as shown in Figure (B), screen distortion as shown in Figure 5 (B) will occur due to differences in the travel distance of the electron beam. be.

Conventionally, to correct this, a circuit was used or a magnetic piece 4 was attached as shown in FIG.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a deflection yoke that can produce a good screen without distortion in a flat tube without requiring correction by a circuit or by a magnetic piece.

[Summary of the invention]

In order to achieve the above object, the deflection forces of the upper and lower horizontal coils must be made unbalanced. However, in the present invention, the deflection sensitivity can be changed by changing the coil length of each of the upper and lower horizontal coils, or This was achieved by changing the number of turns in the upper and lower horizontal coils to change the inductance.

[Embodiments of the invention]

The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a side view showing an embodiment of the present invention.

In the figure, 2 is an upper horizontal coil, and 3 is a lower horizontal coil. It is.

As seen in FIG. 1, by making the length of the lower horizontal coil 3 larger than the length of the upper horizontal coil 2, the deflection sensitivity of the lower horizontal coil 3 is increased.

The screen distortion shown in FIG. 5(0) is improved.

FIG. 2 is a wiring diagram of upper and lower horizontal coils to show another embodiment of the present invention.

Figure 2 shows that in each of the upper and lower horizontal coils connected in parallel,
By making the inductance LB of the lower horizontal coil 3 smaller than the inductances I and A of the upper horizontal coil 2, the amount of deflection is increased by increasing the current iB flowing through the lower horizontal coil 3 (iB>iA), The screen distortion shown in FIG. 5(B) is improved to a good screen without distortion as shown in FIG. 5(B).

〔Effect of the invention〕

According to the present invention, screen distortion, which was conventionally corrected using a circuit and a magnetic piece in a flat tube, can be corrected only by a deflection yoke, and a very inexpensive system can be obtained.

[Brief explanation of drawings]

Fig. 1 is a side view showing one embodiment of the present invention, Fig. 2 is a wiring diagram of upper and lower horizontal coils to show another embodiment of the invention, Fig. 3 is a perspective view of a flat tube, and Fig. 4 is a side view showing an embodiment of the present invention. Figure (A) is a front view of a conventional deflection yoke, Figure 5-) is a side view, Figure 5B) is an explanatory diagram showing good screen distortion, and Figure (CI) is a correction circuit and a conventional deflection yoke. FIG. 6 is an explanatory diagram showing screen distortion when no magnetic piece is used. 1...Flat tube screen 2...Upper horizontal coil 3
... Lower horizontal coil 4 ... Magnetic piece porridge 1 Figure 5 Punishment Figure 2

Claims (1)

[Claims] 1. A deflection yoke having a pair of upper and lower horizontal coils is characterized by having an unbalanced deflection force between the upper and lower sides by making the coil lengths of the upper and lower horizontal coils different or by making the number of turns of the upper and lower horizontal coils different. deflection yoke.