JPH01236556A - Deflection yoke - Google Patents

Abstract

PURPOSE:To provide good focusing characteristic by incorporating such an arrangement that the intermediate regions of a horizontal deflecting magnetic field have a distortion smaller than the pin cushion tending distortion in the regions beside each intermediate region, or a distortion in barrel tending. CONSTITUTION:No.1 and No.2 magnetic substance pieces 4, 5 are equipped with respective main face parts 4a, 5a, which mate each other with a vertical plane interposed and are coupled magnetically with the electron gun side region of the vertical deflecting magnetic field, and two divergent parts 4b, 4c, 5b, 5c which extend horizontally from the top edges and bottom edges of these main face parts 4a, 5a and protrude along the external surface of a cylindrical part 3c toward the electron gun. A horizontally deflecting coil 1 is fitted with a row of windings to distort the intermediate regions of the horizontal deflecting magnetic field in a degree smaller than the pin cushion tending distortion in the regions beside each intermediate region, or in the barrel tending. This provides a good focusing characteristic in the whole area of the screen of an in-line type color image receiving tube, and image reproduction with high resolution is embodied.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a deflection yoke mounted on an in-line color picture tube having three electron beam emission ports arranged horizontally and linearly.

2. Description of the Related Art In general, a self-convergence deflection yoke mounted on an in-line color picture tube generates a horizontal deflection magnetic field that is distorted as a whole in a pincushion tendency and a vertical deflection magnetic field that as a whole is distorted as a barrel tendency. However, the cross-sectional shape of the electron beam that has passed through such a deflection magnetic field is distorted by so-called deflection distortion, making it impossible to obtain good focusing characteristics (that is, as shown in Figure 7, the cross-sectional shape of the electron beam is distorted by so-called deflection distortion. The beam spot b+g+r is distorted non-circularly at the periphery of the screen, and unless this problem is solved, high-resolution image reproduction cannot be expected.

Therefore, the present inventors developed a deflection yoke as disclosed in Japanese Patent Application Laid-open Nos. 62-217546 and 62-237648. This deflection yoke has a pair of magnetic pieces at the end on the electron gun side, and the magnetic pieces distort the electron gun side region of the vertical deflection magnetic field into a pincushion tendency.

When a deflection yoke constructed in this manner is used, a beam spot shape as shown in FIG. 8 is obtained, and good focusing characteristics can be obtained even in the peripheral area of the screen. However, the improvement effect in areas near the left and right edges of the screen was not sufficient.

Problems to be Solved by the Invention Accordingly, an object of the present invention is to provide a deflection yoke that can obtain good focus characteristics over the entire screen.

Means for Solving the Problems The deflection yoke of the present invention includes a horizontal deflection coil that generates a horizontal deflection magnetic field that is distorted as a whole in a pincushion tendency, and a vertical deflection coil that generates a vertical deflection magnetic field that is distorted as a whole in a barrel tendency. , an insulating frame that supports both horizontal and vertical deflection coils and has a cylindrical portion on the electron gun side, and first and second magnetic pieces. The first and second magnetic material pieces have a main surface portion facing each other via a vertical plane and magnetically coupled to the electron gun side chain region of the vertical deflection magnetic field, and an upper edge and a lower end of the main surface portion. The horizontal deflection coil has two branch parts extending horizontally from the edge and protruding toward the electron gun side along the outer surface of the cylindrical part, and the horizontal deflection coil has two branch parts extending horizontally from the edge thereof and protruding toward the electron gun side, and the horizontal deflection coil has two branch parts extending horizontally from the edge thereof and protruding toward the electron gun side. It has a winding arrangement for less than pincushion tendency distortion or barrel tendency distortion. However, by means of a magnetic piece or a permanent magnet piece added to the insulating frame, the intermediate region of the horizontal deflection magnetic field can be distorted in a barrel tendency or smaller than the pincushion tendency distortion in both side areas.

Effect With this configuration, the intermediate region of the horizontal deflection magnetic field is smaller than the pincushion tendency distortion (or barrel tendency distortion) in the regions on both sides, so that the electron beam cross section is greatly affected by the magnetic field distortion in the intermediate region. It is possible to reduce shape distortion in the horizontal direction.
If the overall pincushion tendency distortion of the horizontal deflection magnetic field is insufficient due to this configuration, barrel-type misconvergence will occur on both the left and right sides of the screen (near ml i ), or pincushion-type misconvergence will occur at the corners of the screen. Convergence is likely to occur. However, the former can be corrected by dynamic convergence means using a convergence correction circuit only in the horizontal direction, and the latter can be corrected by adjusting the winding distribution of both the horizontal and vertical deflection coils.

Embodiments Next, the deflection yoke of the present invention will be explained in detail together with embodiments shown in the drawings.

As shown in Figures 1 and 2, there is a saddle-shaped horizontal deflection coil 1 that generates a horizontal deflection magnetic field that is distorted as a whole in a pincushion tendency, and a toroidal type that generates a vertical deflection magnetic field that is distorted as a whole in a barrel tendency. vertical deflection coil 2
The synthetic resin insulating frame 3 supporting the cone-shaped portion 3
It has a box-shaped part 3b and a cylindrical part 3c, and first and second magnetic pieces 4.5 are attached to the cylindrical part 3c located on the electron gun side. Both magnetic pieces 4 and 5 are magnetically coupled with the leakage magnetic field from the vertical deflection coil 2 at the main surface portions 4a and 5a that face each other via a vertical plane including the tube axis, and the upper end edges of the main surface portions 4a and 5a are magnetically coupled to each other. and two branch portions 4b, 4c, and 5b extending horizontally from the lower end edge and protruding toward the electron gun side along the cylindrical portion 3C.

5C, a vertical deflection magnetic field region with a pincushion tendency as shown by the solid line a in FIG. 3 is generated on the electron gun side.

The characteristic shown by the broken line in FIG. 3 is the distribution on the tube axis of the vertical deflection magnetic field generated in the self-convergence deflection yoke without the magnetic pieces 4 and 5, and the thin vertical line indicates the deflection center position.

On the other hand, the horizontal deflection magnetic field has a distribution with a pincushion tendency as a whole, as shown by the solid line a in Fig. 4, but in the intermediate region including the deflection center position, it is distorted in a barrel tendency, and in the regions on both sides It is distorted into a pincushion tendency. The characteristic already shown by the broken line in FIG. 4 is the distribution on the tube axis of the horizontal deflection magnetic field generated in a typical self-convergence deflection yoke.

Means for distorting the intermediate region of the horizontal deflection magnetic field, which should be distorted in a pincushion tendency as a whole, to be smaller than the pincushion tendency distortion in the regions on both sides or in a barrel tendency, is to change the window width in the middle part of the horizontal deflection coil 1 or the winding. This can be obtained by simply adjusting the winding arrangement such as distribution. Also, the opposite 1
This can also be achieved by attaching magnetic field control means consisting of a pair of arcuate magnetic pieces or permanent magnet pieces to appropriate locations on the outer or inner surface of the insulating frame.

If the distortion in the intermediate region of the horizontal deflection magnetic field is made to have a barrel tendency as described above, the effect may extend to the electron gun side and give an asymmetrical deflection effect to the electron beams on both sides.

Therefore, the electron gun side region of the horizontal deflection magnetic field is distorted to have a pincushion tendency.

When a deflection yoke constructed in this manner is attached to an in-line color picture tube and operated, a beam spot shape as shown in Fig. 5 can be obtained, and good focusing characteristics can be obtained over the entire screen area. can.

However, if the pincushion tendency distortion of the horizontal deflection magnetic field is insufficient compared to the conventional one, as shown in Figure 6, the electron beams on both sides may A barrel-shaped misconvergence may occur between the red raster R and the blue raster B. Such misconvergence can be solved by, for example, providing a plurality of pairs of pole pieces at the tip of the electron gun, a convergence yoke that is magnetically coupled to the pole pieces outside the tube, and applying a dynamic current for correction to the coil of the convergence yoke. This can be corrected by communicating with each other, and since this correction only needs to be done in the horizontal direction, it can be configured relatively simply.

Effects of the Invention According to the present invention, as described above, it is possible to obtain good focus characteristics over the entire screen of an in-line color picture tube, and it is possible to reproduce images at high resolution.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views of a deflection yoke according to the present invention, Figure 3 is a distribution characteristic diagram of the vertical deflection magnetic field generated by the deflection yoke on the tube axis, and Figure 4 is the horizontal deflection generated by the deflection yoke. Figure 5 is a schematic diagram showing the shape of the beam spot generated on the screen surface of an in-line color picture tube equipped with the same deflection yoke, and Figure 6 is a diagram showing the distribution characteristics of the magnetic field on the tube axis. Figures 7 and 8 are schematic diagrams for explaining the misconvergence that occurs, and are diagrams schematically showing the shape of a beam spot generated on the screen surface of a color picture tube equipped with a conventional deflection yoke. . l...Horizontal deflection coil, 2...Vertical deflection coil, 3...Insulation frame, 4, 5...
・Magnetic material piece. Name of agent: Patent attorney Toshio Nakao and one other person
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Claims (2)

[Claims] (1) A horizontal deflection coil that generates a horizontal deflection magnetic field that is distorted as a whole in a pincushion tendency, and a vertical deflection coil that generates a vertical deflection magnetic field that is distorted as a whole in a barrel tendency;
An insulating frame supporting both horizontal and vertical deflection coils and having a cylindrical portion on the electron gun side, and first and second magnetic pieces,
The first and second magnetic pieces have a main surface portion that faces each other via a vertical plane and is magnetically coupled to the electron gun side region of the vertical deflection magnetic field, and a horizontal portion that extends from the upper and lower edges of the main surface portion. and two branch portions extending along the outer surface of the cylindrical portion and protruding toward the electron gun side, and the horizontal deflection coil has a pincushion tendency distortion in the intermediate region of the horizontal deflection magnetic field on both sides thereof. A deflection yoke characterized in that the windings are arranged to cause distortion to be smaller or to have a barrel tendency. (2) a horizontal deflection coil that generates a horizontal deflection magnetic field that is distorted as a whole in a pincushion tendency, and a vertical deflection coil that generates a vertical deflection magnetic field that as a whole is distorted as a barrel tendency;
an insulating frame supporting both horizontal and vertical deflection coils and having a cylindrical portion on the electron gun side; first and second magnetic material pieces; and magnetic field control means; The piece includes a main surface portion that faces each other via a vertical plane and is magnetically coupled to the electron gun side region of the vertical deflection magnetic field, and a main surface portion that extends horizontally from the upper and lower edges of the main surface portion of the cylindrical portion. and two branch portions protruding toward the electron gun along the outer surface, and the magnetic field control means distorts the intermediate region of the horizontal deflection magnetic field to be smaller than the pincushion tendency distortion in both side regions or to a barrel tendency. A deflection yoke comprising a magnetic piece or a permanent magnet piece added to the insulating frame.