JPH06197233A - Deflection yoke - Google Patents

Abstract

PURPOSE:To attain the accurate correction of the upper-lower bobbin distortions without using any additional object like a magnet, etc., by forming an adverse winding part by means of the winding of a horizontal deflection coil. CONSTITUTION:A current which deflects in the direction opposite to the deflecting direction is energized at the upper and lower half adverse winding parts 30c. So that a multipolar (6 polses) magnetic field is generated. This means that the tertiary higher harmonic component having a 3-fold cycle is increased to a horizontal deflection magnetic field. For this purpose, the parts 30c are arranged at the center part of the tube axis direction having an angle larger than 30 deg. against a horizontal axis. Thus a magnetic field of the opposite polarity is generated to a main horizontal deflection magnetic field by the presence of the parts 30c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke used in an in-line type color cathode ray tube (hereinafter referred to as CRT), and more particularly to a deflection yoke capable of easily and accurately correcting upper and lower pincushion distortion. Is.

[0002]

2. Description of the Related Art A conventional deflection yoke 1 as shown in FIG.
Generally, the horizontal deflection coil 3 is wound in a square shape on the inner surface of the coil frame 2 via the coil frame 2 and
A vertical deflection coil 4 having a square shape is attached to the outer circumference of the vertical deflection coil 4 and the outer circumference of the vertical deflection coil 4 is surrounded by a magnetic core 5. Guide portions 2a and 2b having a plurality of winding grooves 6 are formed at the end of the coil frame 2 on the screen (phosphor screen) side and the end of the coil frame 2 on the electron gun side.

FIG. 7 is a view showing the upper half of the horizontal deflection coil 3 wound around the coil frame 2. FIGS. 7A and 7B show the horizontal deflection coil 3 wound by a conventional method. 2A and 2B are a view seen from the screen side and a view seen along the tube axis, respectively. The coil 3c at the center is wound in the same direction from the electron gun side to the screen side end, like the coils 3a and 3b at both ends. ing.

When such a pair of horizontal deflection coils is mounted on the CRT in a pair, the upper and lower pincushion distortions are generated on the screen as shown by the solid line 7 in FIG. For this reason, in the conventional deflection yoke, a magnet is installed on the screen side to correct the upper and lower pincushion distortion as shown by a broken line 8 in FIG.

When the upper and lower pincushion distortions are corrected by a method of installing a magnet on the side of the deflection yoke screen, an in-line type CR is used due to the influence of the magnetic field generated by the magnet.
At T, horizontal misconvergence Y _H occurs between the red electron beam R and the blue electron beam B at the end of the vertical axis (Y axis) as shown in FIG. Although this Y _H amount can be corrected to Y _H = 0 by adjusting the barrel magnetic field distribution of the magnetic field of the vertical deflection coil, the upper and lower pincushion distortion changes in the direction of the solid line 7 shown in FIG. 8, and as shown in FIG. At the corner, vertical misconvergence PQ _V remains. Therefore, the size of the magnet is adjusted again, the magnetic field distribution of the horizontal deflection coil and the vertical deflection coil is adjusted, and the positions of the horizontal deflection coil and the vertical deflection coil are changed in the tube axis direction.
As well as the correct vertical pincushion distortion as shown by a broken line 8 shown in FIG. 8, Y _H, are corrected misconvergence PQ _V.

[0006]

As described above, in the conventional deflection yoke, the upper and lower pincushion distortions are corrected by installing a magnet at the end portion on the screen side. In this method, the horizontal direction due to the magnetic field of the magnet is used. Misconvergence Y _H occurs, and it is necessary to adjust the magnetic field distribution of the vertical coil again. To correct the change in the vertical misconvergence PQ _V , the position of the tube axis of the horizontal deflection coil is reviewed. There were some problems, such as the necessity.

Further, as a conventional technique which does not use a magnet as described above, as shown in, for example, Japanese Patent Laid-Open No. 3-145039, a reverse winding is added to a part of a horizontal deflection coil to partially deflect the deflection magnetic field. There is also a method of changing it, but there is a problem that the additional method such as requiring a complicated coil frame is very cumbersome and not practical, and the upper and lower pincushion distortion cannot always be sufficiently corrected.

The present invention has been made in order to solve the above-mentioned problems, and does not require a special magnet for correcting the upper and lower pincushion distortions, and simply crosses a part of the horizontal deflection coil winding. It is an object of the present invention to provide a deflection yoke suitable for an in-line type CRT, in which the upper and lower pincushion distortions can be easily and accurately corrected.

[0009]

In the deflection yoke according to the present invention, the horizontal deflection coil winding is made to intersect at the central portion in the tube axis direction at a position where the angle from the horizontal axis is larger than 30 degrees. A reverse winding portion is formed from the central portion in the tube axis direction to the screen side, and a magnetic field having a polarity opposite to that of the main horizontal deflection magnetic field is generated.

[0010]

In the deflection yoke according to the present invention, the magnetic field generated from the reverse winding portion of the horizontal deflection coil winding and the magnetic field generated from the main horizontal deflection coil wound in the normal direction are combined to form a screen of the deflection yoke. A stronger pincushion-shaped magnetic field is formed at the side edges to accurately correct upper and lower pincushion distortions.

[0011]

EXAMPLES Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 (A) is a view of the upper half of the pair of horizontal deflection coils as seen from the screen side, and FIG. 1 (B) is a view of the same deflection coil as seen along the tube axis. It represents. In FIG. 1, reference numeral 20 denotes a coil frame, which has guide grooves 20a and 20b for restricting the positions of the main deflection coil portions at positions near the horizontal axis on the screen side and the electron gun side, respectively, and has an angle of 30 degrees from the horizontal axis. A screen side guide portion 20c and an electron gun side guide portion 20d for forming a reverse winding portion of a horizontal deflection coil winding, which will be described later, are provided at larger positions. Winding guide grooves are formed around the screen side guide portion 20c and the electron gun side guide portion 20d, and a space portion 20e for intersecting the horizontal deflection coil winding is formed between the guide portions. There is.

Reference numeral 30 denotes a horizontal deflection coil winding, which is a coil frame 2.
Main deflection coil portions 30a and 30b wound in the zero deflection guide grooves 20a and 20b in the normal deflection direction, and the reverse winding portion 30c wound in the screen side guide portion 20c in the opposite direction to the main deflection coil portion. And a winding portion 30d wound around the electron gun side guide portion 20d in the same direction as the main deflection coil portion.
And an intersecting portion 30e located in the space 20e, a horizontal deflection current is passed through the inlet end 30f and the outlet end 30g in the direction of the arrow in the figure.

FIG. 2 shows a reverse winding portion 30c when the horizontal deflection coils shown in FIG.
FIG. 4 is a schematic cross-sectional view perpendicular to the tube axis, including the direction of the horizontal deflection current when the electron beam emitted from the electron gun of the CRT is scanned leftward when viewed from the CRT screen side. A current is applied to the reverse winding portions 30c of the upper half portion and the lower half portion in a direction of deflection in the direction opposite to the deflection direction.

When the electric current is applied in this manner, the direction of the magnetic field formed by each coil portion becomes as shown by the arrow in FIG. 2, and a multipole magnetic field of 6 poles is formed. This means that the third-order harmonic component whose period is tripled is stronger than the main horizontal deflection magnetic field. In order to strengthen the third harmonic component, the reverse winding portion 30c is arranged at the central portion in the tube axial direction at a position where the angle from the horizontal axis is larger than 30 degrees. FIG. 3 shows the harmonic components of the magnetic potential shown in polar coordinates for such a horizontal deflection magnetic field, where Ha is the fundamental wave portion, and Hb
Is the third harmonic. The composite magnetic field of the fundamental wave and the third harmonic is Hc shown by the broken line. This composite magnetic field is shown in FIG.
The equipotential magnetic lines shown by the solid lines are formed and have a strong pincushion shape.

This pincushion-shaped magnetic field exerts a force on the screen in the direction indicated by the arrow in FIG. 5, and corrects the upper and lower pincushion distortion shown in FIG. Therefore, the magnitude of the third high-frequency component is changed according to the number of windings and the position of the reverse winding portion 30c, and the pincushion-shaped magnetic field is adjusted to accurately adjust the correction amount according to the remaining amount of the upper and lower pincushion distortions. Can be adjusted to

Example 2. In the above embodiment, the increase and decrease of the third high-frequency component is explained, but by providing a plurality of reverse winding portions 30c, the higher fifth-order harmonic component of the 10-pole magnetic field component and the 14-pole magnetic field component, The 7th harmonic component can be controlled, and the upper and lower pincushion distortions can be corrected with higher accuracy.

[0017]

In the deflection yoke according to the present invention, the horizontal deflection coil winding is intersected at the central portion in the axial direction of the tube at a position where the angle from the horizontal axis is larger than 30 degrees, so that the central portion of the horizontal deflection coil in the axial direction of the tube is expanded. Since it is configured to form a reverse winding portion from the section to the screen side and generate a magnetic field of opposite polarity with respect to the main horizontal deflection magnetic field, it is possible to generate harmonics with respect to the main deflection magnetic field without using an additive such as a magnet. By controlling the components, the upper and lower pincushion distortions can be accurately corrected. Further, since it is only necessary to provide the intersecting portion in a part of the horizontal deflection coil winding, there is an effect that it can be easily implemented without requiring a complicated coil frame or the like.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG.
Is a front view of the upper half of the pair of horizontal deflection coils as seen from the screen side, and FIG.
It shows a plan view of the same deflection coil as seen along the tube axis.

FIG. 2 is a schematic cross-sectional view perpendicular to the tube axis when the horizontal deflection coils shown in FIG. 1 are mounted in a pair on the CRT in a vertical arrangement, and show the directions of magnetic poles and magnetic lines of force by each coil portion.

FIG. 3 is a diagram for explaining a magnetic field component by the horizontal deflection coil shown in FIG.

FIG. 4 is an explanatory diagram showing a combined magnetic field generated by the horizontal deflection coil shown in FIG.

5A and 5B are views for explaining the pincushion distortion correction action by the combined magnetic field of FIG.

FIG. 6 is a side view showing an example of a conventional deflection yoke.

FIG. 7 is a diagram showing an example of a conventional horizontal deflection coil,
(A) is a front view and (B) is a plan view.

FIG. 8 is an explanatory diagram showing upper and lower pincushion distortions on the screen.

FIG. 9 is a diagram for explaining horizontal misconvergence.

FIG. 10 is a diagram for explaining misconvergence in the vertical direction.

[Explanation of symbols]

 20 ... Coil frame 20a ... Guide groove 20b ... Guide groove 20c ... Screen side guide part 20d ... Electron gun side guide part 20e ... Space part 30 ... Horizontal deflection coil winding 30a ... Main deflection coil part 30b ... Main deflection coil part 30c ... Reverse winding part 30e ... Intersection part 30f ... Inlet end 30g ... Outlet end

Claims (2)

[Claims] 1. In a deflection yoke used for an in-line type color cathode ray tube, horizontal deflection is achieved by intersecting horizontal deflection coil windings at a central portion in the tube axial direction at a position where an angle from the horizontal axis is larger than 30 degrees. A deflection yoke, characterized in that a reverse winding portion for generating a magnetic field having a polarity opposite to that of the main horizontal deflection magnetic field is formed from the central portion of the coil in the tube axis direction to the screen side. 2. The deflection yoke according to claim 1, wherein the reverse winding portion controls a magnetic field of a harmonic component with respect to the main horizontal deflection magnetic field.