JPH04209448A - Deflection yoke - Google Patents

Abstract

PURPOSE:To accomplish compensation of pin cushion barrel distortion with high accuracy as well as focusing with high resolution by arranging a slot formed inside a ferrite core in a specified relation between an angle at a neck part and an angle of screen part. CONSTITUTION:In a deflection yoke for image pick-up tube, vertical deflection coiling is applied to a plurality of slots 13 formed at the inner face of annular magnetic ferrite core 11 in a funnel shape, and further onto the inner face horizontal deflection coiling is applied. A part of each slot 13 is cut slantly without cutting it radially. Namely, in an angle measured from a horizontal axis to the center of a groove is formed such that the angle of other slots at a neck part than a 1st or 2nd slot on the side of the horizontal axis is made smaller than the angle at a screen part. With a core with such a constitution, the distribution of vertical deflection magnetic field can be controlled in a barrel shape at the neck side while in a pin cushion shape at the screen side. It is thus possible to have focusing with high resolution and perform compensation of pin cushion-barrel distortion with high accuracy.

Description

[Detailed description of the invention]

[00011

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke for a picture tube device. [0002] Conventionally, as a deflection yoke mounted on a picture tube, a plurality of slots are formed on the inner surface of a bosh-shaped annular magnetic ferrite core and a vertical deflection winding is used for the purpose of improving deflection sensitivity. Wires and horizontal deflection windings inserted into these slots have been used. Since the slot precisely regulates the position of the coil winding, a highly accurate product with little variation is achieved. [0003] In conventional deflection yokes, the angles of the slots provided on the inner surface of the core are set to be equal. Therefore, the deflection winding inserted into the slot and wound is at the front end (screen side) and rear end (neck side) of the core.
The disadvantage is that the winding position (winding distribution) of the winding is limited and it is difficult to arbitrarily obtain a winding distribution that will obtain the desired deflection magnetic field. was there. [0004] Figures 11 to 15 show the structure of a conventional deflection yoke. Ferrite core 1 as shown in Figures 11 to 13
has a plurality of slots 3 extending in a direction along the tube axis,
It has teeth 5 in between. When viewed from the tube axis direction, the slots 3 are exactly radial. In addition, as shown in FIGS. 14 and 15 (the hooks for hooking the ends of the windings are omitted), there are a vertical winding 7 that generates a horizontal magnetic field and a horizontal winding 9 that generates a vertical magnetic field. When this is applied, the magnetic field strength distribution on the tube axis becomes as shown in FIG. When the magnetic field distribution on the tube axis is determined, the distribution is close to a uniform magnetic field as shown in FIG. 17. As can be seen from this figure, the magnetic field distribution in the cross section on the neck side and the screen side is a substantially uniform uniform magnetic field distribution, although it has a slight pincushion distribution as shown in FIGS. 18 and 19. When an actual electron beam is deflected using this deflection yoke, a pincushion-shaped raster as shown in FIG. 20 appears on the screen. When this is corrected using a conventional permanent magnet, a horizontal raster as shown in FIG. 21 appears. Although the figure is exaggerated, in reality, a raster with almost -like distortion and little distortion can be obtained. [0005]

Problems to be Solved by the Invention In the conventional ferrite cores shown in FIGS. 11 to 15, it is almost impossible to adjust the winding distribution, so it is impossible to independently control both focus and distortion to obtain a high-quality image. For example, if pincushion distortion or barrel distortion is properly corrected, the focus will drop and it will no longer be possible to obtain a high-resolution image. [0006] In order to solve this problem, a ferrite core has been proposed in which the direction of the slot is branched in a figure 7 shape from the radial direction on the screen side (Actual Fair 1
-21473). This allows the magnetic field distribution on the screen side to be controlled independently from the neck side. However, according to this method, although the winding distribution on the screen side can be arbitrarily adjusted to some extent, it is not only difficult to position the windings, but also because the neck side is not adjusted, it is necessary to achieve both distortion correction and focus correction. It becomes insufficient. [0007] Accordingly, it is an object of the present invention to provide a deflection yoke whose winding distribution is such that both distortion and focus can be corrected. [00081

[Means for Solving the Problems] The present invention provides a deflection tube for picture tubes in which vertical deflection windings are applied to a plurality of slots formed on the inner surface of a morning glory-shaped annular magnetic ferrite core, and horizontal deflection windings are further provided on the inner surface of the slots. In the yoke, the angle of the slot measured from the horizontal axis perpendicular to the tube axis to the center line of the slot is larger at the screen part than at the neck part of only one or two slots on the horizontal axis side. (Figure 1)
, the same (Fig. 2) or smaller (Fig. 3), and in the remaining majority, the angle at the screen part is larger than the angle at the neck part, and the barrel-shaped magnetic field is formed at the neck side. This is a deflection yoke for picture tubes in which vertical deflection windings are wound around these grooves so that a pincushion-type magnetic field distribution is formed on the screen side. Preferably, the horizontal winding is also wound to produce a similar magnetic field distribution. [00091] According to the present invention, since focus and distortion can be corrected simultaneously, an excellent image with high resolution and low distortion can be obtained. [00101] [Description of Embodiments] FIGS. 1 to 10 are explanatory diagrams of a deflection yoke according to the present invention and its function. [00111 FIGS. 1 to 3 are front views of the morning glory-shaped magnetic ferrite core of the present invention as viewed from the screen side. [0012] FIG. 1 shows a ferrite core 1 according to a first embodiment.
1 and has slots 13 separated by teeth 15. In this example, the slots are almost uniformly distributed on the neck side, but the width of the slot-free area near the horizontal axis (X-axis) increases as you move toward the screen side. Further approaching the vertical axis (Y-axis), the slot 13 tilts toward the vertical axis. To specify more strictly, core 11
The angle measured from the horizontal axis to the center line 16 of the slot 13 on the neck side is θl, and the same angle O2 on the screen side is determined to be θl minus θ2. However, it becomes radial on the vertical axis. The vertical windings 17 are then saddled into these slots 13 using known end hooks (not shown), and the horizontal windings 19 are then saddled into known support frames (not shown). It is configured as shown in FIG. In the figure, the bent portions of the ends of both windings are schematically shown in a state where they are supported by the end hooks. [0013] FIG. 2 shows a morning glory-shaped ferrite core 11 according to a second embodiment. In this example, there is no slot near the horizontal axis on the neck side either. Also, a radial slot is formed at an angle θ3, and at other angles θ1 and θ2 are defined. Vertical windings 17 are then saddled into these slots 13 using known end hooks (not shown), and horizontal windings 19 are then saddled into known support frames (not shown).
It is rolled up into a saddle shape and constructed as shown in Fig. 4. [0014] FIG. 3 shows a morning glory-shaped ferrite core 11 according to a third embodiment. In this example, there is no slot near the horizontal axis on the neck side either. Near the horizontal axis, the slot 13 is parallel to the horizontal axis, and near the vertical axis, the slot 13 is parallel to it. Between the horizontal and vertical axes, θ1〈
02. Vertical windings 17 are then saddled into these slots 13 using known end hooks (not shown), and horizontal windings 19 are then saddled into known support frames (not shown). Roll it up into a shape and configure it as shown in Figure 4. [0015] Furthermore, if horizontal winding is performed using the same winding method, a barrel magnetic field will be generated on the neck side and a pincushion magnetic field will be generated on the screen side. [0016] The results for the horizontal winding set to satisfy the above conditions are listed below. Figure 5 is Figures 1-3
3 shows a rough magnetic field strength distribution on the tube axis of the deflection yoke of the embodiment. [00171 Figure 6 shows the deflection distortion magnetic field of the deflection yoke of the same embodiment. The magnetic field distribution is clearly different from the conventional one, with the neck side being barrel-shaped and the screen side being pincushion-shaped. [00181 FIG. 7 shows the magnetic field distribution on the neck side of the same example. This distribution is quite different from the conventional one. [0019] FIG. 8 shows the magnetic field distribution on the screen side of the same example. [00201 The deflection yoke of this embodiment produces a raster image on the fluorescent screen as shown in FIG. Here is the strain Δ
X' and Δy' can be controlled to be equal to or lower than the strains ΔX and Δy of the conventional core shown in FIG. [00211 If this is subjected to magnetic correction, correction as shown in FIG. 10 is possible, and the distortion can be made equal to or lower than that shown in FIG. 21. [0022] Next, Table 1 shows a comparison between the focus of this embodiment and that of the conventional example. [0023] [Table 1] The measurement conditions are CRT, 110 degrees, 2QpFS tube, high pressure 18 KV, amplitude 370 x 280 mm, residual strain 60
% Remaining pin distortion on one side of part of Usta. Note that the vertical distortion is the percentage of ΔY+ +ΔY2 with respect to the amplitude (280 mm), and the residual distortion is the deviation from a straight line and the half width of 50%. [0024]

Effects of the Invention As described above, according to the core of the present invention, at least the magnetic field distribution of the vertical deflection magnetic field is shaped like a barrel on the neck side.
And since pincushion-type control can be performed on the screen side, high-resolution focus and high-precision pincushion barrel distortion correction are possible, and the drawbacks of the conventional system can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front view of a ferrite core used in a picture tube deflection yoke according to the present invention, viewed from the screen side.

FIG. 2 is a front view of a ferrite core according to a second embodiment of the present invention, viewed from the screen side.

FIG. 3 is a front view of a ferrite core according to a third embodiment of the present invention, viewed from the screen side.

4 is a schematic diagram showing the assembly of a deflection yoke incorporating one of these cores of FIG. 3 or 4; FIG.

FIG. 5 is a graph showing the approximate magnetic field strength distribution on the tube axis of the embodiments shown in FIGS. 1 to 3;

FIG. 6 is a graph showing the magnetic field distribution of the same example.

FIG. 7 is a diagram showing the magnetic field distribution on the neck side of the embodiment of FIG. 6;

8 is a diagram showing the magnetic field distribution on the screen side of the embodiment of FIG. 6. FIG.

FIG. 9 is a diagram showing a raster image on a fluorescent screen according to the same embodiment of FIG. 6;

101 is a diagram showing a raster image obtained by magnetically correcting the deflection yoke of the embodiment of FIG. 6; FIG. FIG. 11 is a perspective view of a ferrite core used in a conventional deflection yoke for a picture tube.

FIG. 12 is a front view of a conventional core viewed from the screen side.

FIG. 13 is a cross-sectional view of a conventional core perpendicular to the tube axis.

FIG. 14 is a front view of a conventional deflection yoke provided with windings, viewed from the screen side.

FIG. 15 is a schematic diagram showing the assembly of a deflection yoke incorporating a.

FIG. 16 is a graph showing the magnetic field distribution on the tube axis of a conventional deflection yoke.

FIG. 17 is a graph showing a distorted magnetic field in an example.

FIG. 18 is a diagram showing the magnetic field distribution on the neck side of the example.

FIG. 19 is a diagram showing the magnetic field distribution on the screen side of the same example.

FIG. 20 is a diagram showing a raster image on a fluorescent screen according to the same embodiment.

FIG. 21 is a diagram showing a raster image obtained by magnetically correcting the deflection yoke of the same embodiment.

[Fig. 8] The measurement conditions are 110 degrees on the CRT and 29 degrees. φ-FS pipe, high pressure 18KV, amplitude 370X280mm, residual strain 60
%Remaining one-sided bin distortion in part of the raster. Note that the vertical distortion is the percentage of △Y+++△Y2 with respect to the amplitude (280 mm), the residual distortion is the deviation from a straight line, and the focus is the half width of 50%.
It is the width.

[Procedural amendment 2]

[Name of document to be amended] Specification

[Correction target item name] Figure 4

[Correction method] Change

[Correction details]

FIG. 4 is a schematic diagram showing the assembly of a deflection yoke incorporating one of the cores of FIG. 3 or FIG. 4;

[Procedural amendment 3]

[Name of document to be amended] Specification

[Correction target item name] Figure 16

[Correction method] Change

[Correction details]

FIG. 16 is a graph showing the magnetic field distribution on the tube axis of a conventional deflection yoke.

[Procedural amendment 4]

[Name of document to be amended] Specification

[Correction target item name] Figure 17

[Correction method] Change

[Correction details]

FIG. 17 is a graph showing magnetic field distribution in an example.

Claims (1)

[Claims] 1. A picture tube deflection yoke in which vertical deflection windings are provided in a plurality of slots formed on the inner surface of a morning glory-shaped annular magnetic ferrite core, and horizontal deflection windings are further provided on the inner surface of the slots, wherein the slots are arranged along the horizontal axis. Is the angle measured from A deflection yoke for picture tubes in which the vertical deflection windings are wound around these grooves so that the neck side has a barrel-shaped magnetic field distribution and the screen side has a pincushion-shaped magnetic field distribution. .