Deflection coil and colour cathode-ray tube fitted with same

Abstract

A deflection yoke which is capable of sufficiently reducing a high order raster distortion (gullwing) at the upper and lower edges of the screen without damaging coil wires of the screen side flange portion at the time of winding the horizontal deflection coil. A deflection yoke is formed with a saddle shaped horizontal deflection coil 1, a saddle shaped vertical deflection coil 2 located outside the horizontal deflection coil 1, and a ferrite core 3 located outside the vertical deflection coil 2. The screen side cone portion 1a of the horizontal deflection coil 1 is wound with a winding angle range from 1 DEG to 80 DEG with a higher density of winding distribution in the range from 18 DEG to 30 DEG with the horizontal axis as the standard. The head point in the direction of screen side tube axis 4 of the screen side cone portion 1a of the horizontal deflection coil 1 is located 30 mm away from the screen side tip portion 3a of the ferrite core 3.

Description

technical field [0001] The present invention relates to a deflection yoke and a color cathode ray tube equipped with the deflection yoke. Background technique [0002] In color cathode ray tubes used in display monitors in recent years, windows (windows) are typified, and the frequency of displaying information on the peripheral portion of the screen is very high. Therefore, it is required that a fine image can be expressed in this portion. [0003] Raster distortion is one of the important factors that determine the image quality of the peripheral part of the screen, and the requirements for the raster distortion of the screen (its quality is controlled by the magnetic field distribution of the deflection yoke itself) are very strict. [0004] Generally, the magnetic field distribution in the screen-side cone portion of the saddle coil used as a horizontal deflection yoke has strong pincushion distortion in order to remove raster distortion at the upper and lower ends of t...

AI Technical Summary

Problems solved by technology

[0007] However, in the method disclosed in U.S. Patent No. 4,233,582, in the pressing process in which only the central portion of the flange of the horizontal deflection coil or the vertical deflection coil on the screen side is collapsed toward the central axis of the cathode ray tube, there is a winding of the coil. A manufacturing problem in which the wire material is stretched abnormally and has a high probability of being damaged

In addition, if the concave shape is formed too deep, there will be problems in the following manufacturing and design aspects: when the deflection yoke is mounted on the cathode ray tube, since the concave shape should be properly engaged with the funnel portion of the cathode ray tube, Therefore, it is difficult to form a sufficient concave shape to remove high-order raster distortion such as "gull wings"

In addition, if the concave shape is formed too deep, there will be the following manufacturing and design problems: when the deflection yoke is installed, it is difficult to form the concave shape due to the proper engagement of the concave shape with the tapered portion of the horizontal deflection yoke. Sufficient concave shape to remove "gull wings"

In addition, the method disclosed in U.S. Patent No. 4,229,720 has a problem in manufacturing that the winding material of the coil is abnormally abnormal at the corner portion of the polygonal shape of the screen side flange of the horizontal deflection yoke or the vertical deflection yoke. deformed, more likely to be damaged

Therefore, even if the distortion of the horizontal magnetic field is controlled by the winding distribution of the deflection yoke to minimize the deflection aberration, the distortion of the magnetic field becomes gentle due to the "core magnetic field effect" of the iron core body core, so in this state There is a problem that the correction sensitivity of deflection aberration decreases

[0009] In addition, in the method disclosed in JP-A-2-216738, there is a problem in manufacturing that abnormality occurs in the winding material of the coil in the pressing process for providing convex shapes at the left and right ends of the screen-side flange portion of the saddle-shaped coil. Stretches, so there is a greater chance of injury

In addition, if the convex shape is formed too high, there are problems in the following manufacturing and design aspects: when mounting the deflection yoke, the horizontal deflection yoke, the vertical deflection yoke, and the ferrite core must be properly bonded to each other. Therefore, it is difficult to form a sufficient convex shape to remove high-order grating distortion

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