JP3439540B2 - Deflection yoke device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke device to be combined with a cathode ray tube used for a television receiver, and its influence has become a problem in recent years. The present invention relates to a deflection yoke that can reduce unnecessary magnetic fields. 2. Description of the Related Art Generally, unnecessary radiation in a television receiver is caused by a leakage magnetic field from a deflection yoke device through which a horizontal deflection current flows, a flyback transformer, a horizontal amplitude adjustment coil, a horizontal linearity coil, and the like. I have. Of the unnecessary radiation to the outside, the deflection yoke is about 70%,
The flyback transformer occupies about 20%, and the horizontal amplitude adjustment coil occupies about 10%. Therefore, there is a demand for suppressing unnecessary radiation from the deflection yoke. FIG. 8 shows a horizontal deflection coil 1 as a saddle coil.
It is a side view of a conventional deflection yoke device in which the vertical deflection coil 2 is also a saddle type coil, and the upper half shows a cross section for explaining the internal structure. 3 in the figure is a core. FIG. 9 is a side view of a conventional deflection yoke device in which a horizontal deflection coil 1 is wound directly on a saddle coil and a vertical deflection coil 4 is wound directly on a core 3 to constitute a toroidal deflection coil. Similarly, the cross section is shown in the upper half. As is apparent from FIGS. 8 and 9, the deflection yoke device mounted on a cathode ray tube (not shown) includes a horizontal deflection coil 1, a vertical deflection coil 2 or 4, and a It is assembled in the order of 3. In the case of the deflection yoke device having such a structure, the leakage magnetic field, which is radiated as unnecessary radiation to the outside of the television receiver and is considered to affect the human body, is generated by the horizontal deflection coil 1. A more leaky magnetic field,
As is clear from FIGS. 8 and 9, even if the forms of the vertical deflection coils 2 and 4 are different, the form of the horizontal deflection coil 1 is generally the same as a saddle type. [0007] Among the saddle-shaped horizontal deflection coils 1, the one that has the largest unnecessary radiation as a leakage magnetic field is the crossover portion of the horizontal deflection coil 1 at the wide end. Hereinafter, the magnetic field radiated from the crossover portion of the wide deflection end of the horizontal deflection coil 1 will be described. FIGS. 10A and 10B show one side of the horizontal deflection coil 1. FIG. 10A is a front view, FIG. 10B is a side view, and FIG. 10C is a top view. Here, 5 is a longitudinal portion for generating a magnetic field for deflecting the electron beam, 5a is a left longitudinal portion, 5b
Is a right longitudinal direction part. Reference numeral 6 is on the widening side of the deflecting coil, and is used for passing an electric wire from the left longitudinal direction portion 5a to the right longitudinal direction portion 5b. Is bent at an angle of about 120 ° at a connecting portion between the longitudinal portion 5 and the crossover portion 6.
Reference numeral 7 denotes a crossover portion on the neck side of the deflection coil 1. FIG. 11 shows the state of a leakage magnetic field from the horizontal deflection coil 1. The magnetic field A is a magnetic field generated in the longitudinal direction portion 5 of the deflection coil, and the magnetic field B is the spreading side of the deflection coil 1. This is a magnetic field generated by the crossover portion 6. Further, the magnetic field of Ba whose magnetic field lines are opposite to the magnetic field of A is a magnetic field that does not contribute to the deflection of the electron beam at all. The magnetic field C is a magnetic field generated by the crossover portion 7 on the neck side of the deflecting coil 1. The magnetic field of Ca, which is opposite to the direction of the magnetic field lines of the magnetic field A, does not contribute to the deflection of the electron beam. It is. [0011] Of these, the magnetic field called unnecessary radiation mainly leaks to the outer periphery of the core, and is mainly caused by the magnetic fields B and C that do not cover the core. That is, the magnetic fields B and C become unnecessary radiation magnetic fields and leak to the outside of the television receiver. [0012] Of the magnetic fields leaking from the two crossover wires 6, 7, especially on the magnetic field side of B, the position is on the surface of the cathode ray tube, so that there is a problem of influence on the person operating the cathode ray tube. It has become. In order to cope with this, conventionally, as shown in FIG. 12, a so-called cancel coil 8 for generating a leakage magnetic field in a direction opposite to that of the horizontal deflection coil 1 is provided, or the entire cathode ray tube device is surrounded by a magnetic shielding plate. Therefore, the level of unnecessary radiation leaking out of the television receiver has been kept low. As described above, in the conventional configuration, a canceling coil for intentionally leaking a magnetic field opposite to the horizontal deflection magnetic field for deflecting the electron beam is provided, or a magnetic shield is provided. It is necessary to take measures to cover the entire television receiver with a plate, and in the case of a cancel coil, from the viewpoint of its power supply, the cancel coil is merely a dummy coil. When this television receiver is used as a display device for a personal computer or the like, the horizontal deflection frequency changes depending on the target display content. Therefore, the amount of unnecessary radiation could not be suppressed, and the design of the optimum cancel coil was not achieved. Further, when the entire television receiver is covered with a magnetic shielding plate, not only is the structure of the television receiver greatly restricted, but also the heat radiation of the television receiver deteriorates. In addition, there is a problem that the television receiver has to be provided with a separate part completely different in purpose from the display device originally intended, resulting in an increase in cost. The present invention has been made to solve the above-mentioned conventional problems, and does not require the addition of a component such as a cancel coil which is not directly related to the deflection of the electron beam.
It is an object of the present invention to provide a deflection yoke device having a low unnecessary radiation level without being covered with a magnetic shielding plate. In order to achieve this object, a deflection yoke device according to the present invention comprises a saddle-shaped horizontal deflection coil whose cross-over portion on the widening side has a shape similar to that of the horizontal deflection coil. The configuration is such that it is formed to be smaller than the inner diameter of the core formed substantially parallel to the curve of the portion where the horizontal deflection coil of the cathode ray tube is located, extending to the crossover portion on the widening side. In this configuration, most of the magnetic field leaking from the horizontal deflection coil is absorbed by the core, so that the unnecessary radiation level to the outside of the television receiver can be suppressed to a low level. An embodiment of the present invention will be described below with reference to the drawings. In one embodiment of the present invention, the same reference numerals are given to the same components as those described in the conventional example, and description thereof will be omitted. The present invention is realized by combining the characteristics of the shape of the core and the characteristics of the shape of the horizontal deflection coil. Therefore, the features of the core shape and the features of the horizontal deflection coil will be described first. FIG. 1 is a side view of a deflection yoke device according to the present invention, and the upper half thereof is shown in a cross-sectional view for easy explanation of the structure. First, as a feature of the shape of the core, as is apparent from FIG. 1, the core 3 has a general shape (ie, a substantially arc-shaped smooth curve from the neck side to the widening side on the inner surface of the core). Has no steps)
2, or has a special form such as to cover the crossover portion 6 on the widening side of the horizontal deflection coil located at a position perpendicular to the tube axis of the cathode ray tube as shown in FIG. in this way,
The core 3 covers not only the longitudinal section 5 of the horizontal deflection coil 1 but also the crossover section 6 on the widening side. In order to prevent the inner surface of the core 3 from having a stepped portion, it is necessary to devise a horizontal deflection coil. Next, features of the shape of the horizontal deflection coil will be described. FIGS. 3A and 3B show one side of the horizontal deflection coil 1 of the present embodiment. FIG. 3A is a front view, FIG. 3B is a side view, and FIG. 3C is a top view. FIG. 4 shows the horizontal deflection coil 1 of FIG. 3 incorporated in a cathode ray tube. As is clear from this figure, the portion of the horizontal deflection coil 1 facing the cathode ray tube is formed substantially in accordance with the curve of the cathode ray tube 9. As can be seen from this figure, the horizontal deflection coil 1 has an outer surface having a gentle arc shape in both the longitudinal direction part 5 and the crossover part 6, so that the horizontal direction deflection coil 1 has a longitudinal direction as seen in the conventional example. It does not have any angle at the connection between the part and the crossover part. Although the horizontal deflection coil 1 has such features, its magnetic field distribution basically matches that of the conventional example. This will be described below. That is, regarding the coil distribution in the vicinity of the crossover wire 6 at the wide-angle end of the horizontal deflection coil 1 which is a problem here, the horizontal deflection coil seen in the conventional example gradually becomes closer to the crossover wire 6 as shown in FIG. The winding angle θ increases (FIG. 3C).
That is, the cross section A- is larger than the winding angle θ1 of the cross section BB ′.
In general, the winding angle θ2 of A ′ is larger. On the other hand, in the case of the horizontal deflection coil of this embodiment,
As shown in the top view of FIG. 6, the flow of the electric wire in the crossover portion 6 on the widening side is wound so that the winding width gradually increases toward the end. That is, the longitudinal portion 5 is a portion that forms the main magnetic field of the deflection coil 1, and the interval W between the points where the longitudinal portion 5 and the crossover portion 6 are connected increases as approaching the end. That is, W2 is wider than W1 in FIG. Therefore, the winding angle θ of the portion gradually increases as approaching the end. That is, similarly to FIG. 5, the winding angle θ2 of the cross section AA ′ is larger than the winding angle θ1 of the cross section BB ′, which is a general coil distribution. A deflection yoke made by combining the horizontal deflection coil 1 and the core 3 having such a shape characteristic is as follows.
The opening-side crossover portion 6 of the horizontal deflection coil 1 is completely housed inside a core made of a magnetic material. Therefore, most of the unnecessary radiation due to the leakage magnetic field generated by the horizontal deflection coil 1 is absorbed by the core 3. FIG. 7 shows the state of magnetic lines of force which do not contribute to the deflection, which cause unnecessary radiation from the crossover portion 6 on the widening side of the horizontal deflection coil 1. As is clear from this figure, the lines of magnetic force generated from the crossover wire 6 at the wide-angle end of the horizontal deflection coil 1 are absorbed by the core, which is mostly a magnetic material, at the outer periphery of the core 3. It can be seen that unnecessary radiation to the outer peripheral part is reduced. In the above embodiment, the deflection yoke device in which both the horizontal deflection coil and the vertical coil are formed in a saddle type has been described. However, the present invention can also be applied to a deflection yoke device in which the vertical deflection coil is formed in a toroidal type coil. The operation is exactly the same, and the effect can be regarded as the same. As is apparent from the above description of the embodiment, according to the present invention, the longitudinal portion of the horizontal deflection coil and the crossover portion on the widening side are located on the horizontal deflection coil of the cathode ray tube. By making it approximately parallel to the curve of the part and making it smaller than the inner diameter of the core, the required magnetic field is the same as that of the conventional example, and the magnetic field leaking from the horizontal deflection coil is large to the core. Since the portion is absorbed, the unnecessary radiation level to the outside of the television receiver can be kept low.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional side view of a deflection yoke device according to an embodiment of the present invention. FIG. FIG. 3 (a) is a front view of one side of a horizontal deflection coil in the deflection yoke device, FIG. 3 (b) is a side view thereof, and FIG. 3 (c) is a top view thereof. FIG. FIG. 5 (a) is a side view showing a horizontal deflection coil spreading side coil distribution observed in a conventional example, FIG. 5 (b) is a side view showing the same, and FIG. FIG. 6 (a) is a side view showing the spread side coil distribution of the horizontal deflection coil of the present invention. FIG. 6 (b) is a top view showing the winding angle. FIG. Explanatory drawing of magnetic lines of force that do not contribute to deflection causing unnecessary radiation from the crossover part on the widening side of the coil. FIG. 9 is a cross-sectional side view of a conventional deflection yoke device in which a vertical deflection coil is also a saddle type coil. FIG. 9 is a toroidal deflection coil in which a horizontal deflection coil is wound in a saddle type coil and a vertical deflection coil is wound in a straight line around an electric wire. FIG. 10 (a) is a front view showing one side of a conventional horizontal deflection coil, FIG. 10 (b) is a side view, FIG. 10 (c) is a top view, and FIG. FIG. 12 is a diagram showing a leakage magnetic field from a deflection coil. FIG. 12 is a schematic configuration diagram of a deflection coil provided with a cancel coil. Explanation of reference numerals: 1 saddle-type horizontal deflection coil 2 saddle-type vertical deflection coil 3 core 5 longitudinal portion 6 Spreading side crossing section 7 Neck side crossing section

Claims (1)

(1) An open side and a neck for connecting the left and right longitudinal portions to each other with a vertical axis extending from the electron gun side to the tube surface side of the cathode ray tube as a boundary. Saddle-shaped horizontal deflection coil composed of a crossover portion on the side, a toroidal type for directly winding an electric wire around a core, or a vertical deflection coil of the same saddle type as the horizontal deflection coil, and a deflection yoke including the core In the apparatus, the shape of the crossover portion of the saddle-shaped horizontal deflection coil on the widening side extends to the crossover portion of the horizontal deflection coil on the widening side, and a curve of a portion where the horizontal deflection coil of the cathode ray tube is located A deflection yoke device characterized in that the deflection yoke device is made smaller than the inner diameter of a core made substantially parallel to the yoke.