JP3479555B2 - Deflection yoke - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke used for a television receiver or the like. 2. Description of the Related Art A deflection yoke system used for a television receiver is of an upper and lower pincushion distortion free type.
As a countermeasure, bar-shaped permanent magnets are used above and below the opening of the deflection yoke. FIG. 5 shows an example of a conventional deflection yoke. Reference numeral 7 denotes an insulating frame to which a core 8 is attached. The deflection yoke includes a horizontal deflection coil for deflecting the electron beam, a vertical deflection coil, and a pair of bar-shaped permanent magnets 9 on the front side and below. In the above deflection yoke, a cathode ray tube (CR)
The electron beam emitted from the electron gun T) is deflected upward by one of the rod-shaped permanent magnets 9, and is deflected by the other.
And the upper and lower pincushion distortions are corrected. The upper and lower pincushion distortion is corrected by the upper and lower bar-shaped permanent magnets,
The correction amount was adjusted by examining the size and arrangement of the permanent magnet. However, in the above-described conventional deflection yoke, when the bar-shaped permanent magnet is weak, the correction of the upper and lower pincushion distortions is reduced as shown by the dotted line in FIG. Is strong, only the central portion is pulled as shown by the dotted line in FIG. 7, and the linearity is lost. Therefore, in order to correct the upper and lower pincushion distortions, the size, shape, and arrangement of the bar-shaped magnet must be sufficiently considered in accordance with the correction amount, and if the correction amount is large, the permanent magnet must be increased. There has been a problem that other characteristics are disadvantageous. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and to efficiently apply a magnetic field of a permanent magnet to an electron beam, thereby reducing inconvenience to other characteristics while reducing the size, shape, and mounting position of the permanent magnet. It is an object of the present invention to provide a deflection yoke that facilitates the study of the above. In order to achieve the above object, the present invention provides a deflection magnetic field for deflecting an electron beam of a cathode ray tube and has a pair of bar-shaped permanent magnets on the upper and lower sides of a front side. In the deflection yoke, substantially L-shaped magnetic pieces are arranged at both ends of the rod-shaped permanent magnet, and the magnetic pieces are arranged to collect a magnetic field (discharge) facing a surface forming a magnetic pole at a longitudinal end of the rod-shaped permanent magnet. ) And a curvature of the opening of the deflection yoke, and a magnetic field emitting (collecting) portion which is curved and extended to the same curvature. According to the present invention, as described above, both ends of a bar-shaped permanent magnet are provided.
A substantially L-shaped magnetic piece is disposed, and the magnetic piece has a magnetic field pickup (emission) portion facing a surface forming a magnetic pole at a longitudinal end of the bar-shaped permanent magnet, and a curvature equal to a curvature of a deflection yoke opening. Since it has a magnetic field emitting (collecting) portion that extends in a curved manner, the bar-shaped permanent magnet and the magnetic piece are arranged at the same distance from the electron beam, so that the range of the magnetic field can be expanded and the magnetic field can be used effectively. It became so. Therefore, the upper and lower pincushion distortions are adjusted by changing the shapes of the bar-shaped permanent magnet and the magnetic piece. FIG. 1 shows an embodiment of a deflection yoke according to the present invention.
This will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes an insulating frame, and 2 denotes a core, which comprises a horizontal deflection coil and a vertical deflection coil for deflecting an electron beam to constitute a deflection yoke. Reference numerals 3 and 3 denote a pair of bar-shaped permanent magnets, which are provided on the periphery of the insulating frame 1 so as to be positioned above and below the front side of the deflection yoke. Reference numerals 4 and 4 denote magnetic pieces, which are arranged at both ends of the bar-shaped permanent magnets 3 and 3, respectively. FIG. 2 is an enlarged perspective view showing the magnetic piece 4.
Is a magnetic field collecting (emitting) section, and 4b is a magnetic field emitting (collecting) section. The magnetic field emission (collection) section 4b has a shape that is curved and extended at the same curvature as the curvature of the opening of the deflection yoke. FIG. 3 is an explanatory diagram of a magnetic field when the magnetic pieces 4 and 4 are arranged at both ends of the bar-shaped permanent magnet 3. The magnetic field collecting (emitting) portions 4a of the magnetic pieces 4, 4 face the ends of the bar-shaped permanent magnet 3, respectively, and the magnetic field emitting (collecting) portion 4b is curved and extends at the same curvature as the curvature of the deflection yoke opening. ing. Therefore, the magnetic piece 4,
4 and the bar-shaped permanent magnet 3 are located at the same distance from the electron beam. In the magnetic piece and the bar-shaped permanent magnet arranged as described above, the magnetic flux coming out of the N pole of the bar-shaped permanent magnet 3 passes through the magnetic field collecting portion 4a of the magnetic piece 4 as shown by the arrow.
The magnetic flux is emitted from the magnetic field emission part 4b. Then, the magnetic flux is collected by the magnetic field collection part 4b of the magnetic piece 4 and enters the S pole of the rod-shaped magnet 3 through the magnetic field emission part 4a. In this way, the roles of the magnetic field collection and emission portions of the magnetic pieces 4, 4 change. If only the rod-shaped permanent magnet 3 is used, the effect on the electron beam is in the range of X in FIG. 3, but when the magnetic pieces 4 and 4 are used as in this embodiment, the effect on the electron beam is not shown. 3, the range was Y, and the upper and lower pincushion distortion correction ranges could be increased. Therefore, as shown in FIG. 4, the distortion of the electron beam 5 before correction can be improved to the electron beam 6 after correction. As described above, the upper and lower pincushion distortions can be easily improved by considering the size, shape, arrangement, and the like of the magnetic pieces. According to the present invention, the magnetic field of the bar-shaped permanent magnet can be efficiently applied to the electron beam by the shape and size of the magnetic piece as described above. Therefore, in order to improve the upper and lower pincushion distortion, the shape and size of the magnetic piece can be changed without increasing the size of the permanent magnet as in the prior art, thereby increasing the correction range and responding to other characteristics. Problems can also be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a deflection yoke shown as one embodiment of the present invention. FIG. 2 is an enlarged perspective view of a magnetic piece. FIG. FIG. 4 is an explanatory view showing before and after correction of an electron beam according to the present invention. FIG. 5 is a side view of a conventional deflection yoke. FIG. 6 shows correction of an electron beam by a conventional deflection yoke. FIG. 7 is an explanatory view showing correction of an electron beam. [Description of References] 3 Bar-shaped permanent magnet 4 Magnetic piece 4a Magnetic field collecting (emitting) section 4b Magnetic field emitting (collecting) section

Claims (1)

(57) Claims 1. In a deflection yoke having a pair of bar-shaped permanent magnets on the front side and above and below, which generates a deflection magnetic field for deflecting an electron beam of a cathode ray tube, A substantially L-shaped magnetic piece is disposed at each of both ends, and the magnetic piece is provided with a magnetic field pickup (emission) part and a deflection part facing a surface forming a magnetic pole at a longitudinal end of the bar-shaped permanent magnet. A deflection yoke, comprising: a curvature of a yoke opening; and a magnetic field emission (collection) portion that is curved and extended to the same curvature.