JPH07326304A - Deflection yoke - Google Patents

Abstract

PURPOSE:To correct misconvergence caused by asymmetrical. winding of a vertical deflection coil. CONSTITUTION:An NS pole magnetic field generating device 9 arranged in a neck part of a deflection yoke and which can turn around a center axis of a cathode-ray tube i.s mounted. Thereby, a magnetic line of force caused by asymmetrical winding of a vertical deflection coil 3 and a magnetic line of force caused by rotation of the NS pole magnetic field generating device 9 are synthesized to make vertical component force of the both magnetic line of forces equal and misconvergence can be corrected surely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke mounted on a cathode ray tube used in a television receiver or the like.

[0002]

2. Description of the Related Art A conventional deflection yoke will be described below.

As shown in FIG. 4, in the electromagnetic deflection method, in order to scan the tube surface within the cathode ray tube 1 with an electron beam, a core of a magnetic material in which the deflection coils of the horizontal deflection coil 2 and the vertical deflection coil 3 are wound. The deflection yoke having the number 4 is held and disposed by the holder 5 on the neck side and the holder 6 on the opening side so as to surround the outside of the tube near the contact portion between the funnel and the neck of the cathode ray tube 1.

As shown in FIG. 5, when the winding 7 of the vertical deflection coil 3 of the toroidal winding is wound around the core 4 asymmetrically with respect to the y-axis (vertical) direction, as shown in FIG. ,
The magnetic force lines 8 of the magnetic field generated from the vertical deflection coil 3 are also asymmetrical with respect to the y-axis, causing misconvergence. The x-axis in the figure indicates the horizontal direction. That is, the force indicated by F _B acts on the blue beam _B and the force indicated by F _R acts on the red beam R by the magnetic force lines 8, but

[0005]

[Outer 1]

The vertical component force indicated by

[0007]

[Outside 2]

What is the vertical component force indicated by?

[0009]

[Outside 3]

As a result, there was a misconvergence as shown in FIG. A broken line B in the drawing indicates a blue beam, and a solid line R indicates a red beam.

In order to correct this misconvergence, a deflection yoke in which a pair of magnetic material pieces are arranged at the neck portion of the cathode ray tube 1 has been invented (for example, Japanese Patent Laid-Open No. 4-19).
No. 6034, Japanese Utility Model Publication No. 4-42037).

[0012]

However, the above-mentioned conventional structure has a problem in that the misconvergence caused by the asymmetric winding of the vertical deflection coil 3 cannot be reliably corrected.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a deflection yoke capable of reliably correcting misconvergence caused by asymmetric winding of a vertical deflection coil.

[0014]

In order to achieve this object, a deflection yoke of the present invention is an NS pole magnetic field generating device which is arranged at the neck portion of the deflection yoke and is rotatable around the central axis of a cathode ray tube. Is provided.

[0015]

In this structure, the NS pole magnetic field generator is rotated to form a proper magnetic field for correcting misconvergence.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In one embodiment of the present invention, the same components as those described in the above-mentioned conventional example are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 1, a feature of this embodiment is that a rotatable NS pole magnetic field generator 9 is added to the holder 5 of the neck portion in the above-mentioned conventional structure. That is, the disk-shaped cover 10 having the guide hole 10a formed therein to be fitted into the guide pin 5a provided upright on the holder 5.
In addition, the NS pole magnetic field generation device 9 including a pair of magnetic bodies is arranged. 9a in a figure shows a conducting wire.

The operation of the deflection yoke constructed as above will be described below. 6 and 7 of the above-mentioned conventional example.
In order to correct the misconvergence caused by the asymmetrical winding of the vertical deflection coil 3 described above, the NS pole magnetic field generator 9 is shown by an arrow A from the initial position shown by the chain double-dashed line as shown in FIG. When rotated in the direction, the magnetic field lines 1 of the magnetic field generated from the NS pole magnetic field generator 9 as shown in FIG.
1 is formed.

[0020] F in this case blue beam 'force indicated by _B is the red beam F' force acts indicated by _R, the each of the force

[0021]

[Outside 4]

And the vertical component shown by

[0023]

[Outside 5]

The vertical component indicated by is explained in FIG.

[0025]

[Outside 6]

The vertical component force indicated by

[0027]

[Outside 7]

Contrary to the relationship with the vertical component force shown by

[0029]

[Outside 8]

The relationship between the magnetic field lines shown in FIG. 6 and FIG.
By combining the magnetic field lines indicated by, the vertical component force of the blue beam force and the red beam force can be corrected to correct the misconvergence.

[0031]

As is apparent from the above description, the present invention has a configuration in which the NS pole magnetic field generator which is arranged around the central axis of the cathode ray tube and is arranged in the neck portion of the deflection yoke is provided. It is possible to realize an excellent deflection yoke capable of reliably correcting misconvergence caused by asymmetric winding of the vertical deflection coil.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a neck portion of a deflection yoke according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing an attaching operation of the NS pole magnetic field generator of the deflection yoke.

3 is an enlarged schematic plan view showing the magnetic force lines of the NS pole magnetic field generator in FIG. 2 and the force due to the magnetic force lines.

FIG. 4 is a partial sectional view of a conventional deflection yoke.

FIG. 5 is a schematic plan view showing a horizontally asymmetric winding state of a vertical deflection coil of the deflection yoke.

6 is an enlarged schematic plan view showing the magnetic force lines of the vertical deflection coil in FIG. 5 and the forces due to the magnetic force lines.

FIG. 7: Illustration of misconvergence

[Explanation of symbols]

 3 Vertical deflection coil (deflection coil) 9 NS pole magnetic field generator

Claims (1)

[Claims] 1. A deflection yoke having a deflection coil for deflecting an electron beam of a cathode ray tube, the NS polar magnetic field being arranged at a neck portion of the deflection yoke and rotatable about a central axis of the cathode ray tube. A deflection yoke provided with a generator.