JPS6376245A - Deflecting yoke - Google Patents

Abstract

PURPOSE:To reduce the unnecessary radiation more effectively, by installing two sets of auxiliary coils at the outside of a deflecting yoke, applying the horizontal deflecting current in the different directions, and covering the desired parts of the coil side of each auxiliary coil with a conductive membrane. CONSTITUTION:The second auxiliary coil 12 is almost equal in form to the first auxiliary coil 10 having the same rounds of winding, and installed to hold the transition wire of a horizontal deflecting coil 1b from the front and the rear sides. A horizontal deflecting current is applied to generate a leakage magnetic field of the polarity inverse to the horizontal deflection coil 1b at the first auxiliary coil 10, while to generate a leakage magnetic field of a normal polarity at the second auxiliary coil 12. Furthermore, a conductive membrane 13 such as a copper foil is installed to cover parts of the coil sides 12a at the front and the rear of the second auxiliary coil 12, and a part of the coil side 10c parallel to the axis of the first auxiliary coil 10 respectively, to prevent the generation of the leakage magnetic fields from those parts.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a deflection yoke that aims to reduce the level of unnecessary radiation.

[Prior art 1 For example, F! Verband De
utscber Elsktoratechniker
) The unnecessary radiation control frequency required by the standard is 10KH.
z or more, and in the cathode ray tube display device d, unnecessary radiation generated by the horizontal deflection current becomes a problem.

Unnecessary radiation comes from the deflection yoke through which the horizontal deflection current flows, the flyback transformer, and the horizontal width adjustment coil.

This is caused by the leakage magnetic field of the horizontal linearity adjustment coil, and of the amount of unnecessary radiation to the outside, the deflection yoke accounts for approximately 70%, the flyback transformer accounts for approximately 20%, and the horizontal width adjustment coil accounts for approximately 10%. ing.

FIG. 2(a) is a side view of the deflection yoke (1), and the core (1) is a side view of the deflection yoke (1).
a) and only the horizontal deflection coil (1b) are shown. Figure 2 (b) is a cross-sectional view taken along line bb in Figure 2 (a), and when a horizontal deflection current flows through the horizontal deflection coil (lb), at a certain moment a magnetic field is generated in the direction indicated by the dashed arrow. occurs. In this case, a horizontal deflection magnetic field (6C) in the vertical direction is generated in the space surrounded by the core (1a), and at the same time, a cross line (lc) is generated in the front and rear of the horizontal deflection coil (ib).
, (ld) respectively have leakage magnetic fields (8a),
(8b) is generated and radiated to the external space.

Figure 3 is a partially exploded perspective view of a cathode ray tube display device equipped with a conventional unnecessary radiation prevention device, including a deflection yoke (1) attached to a cathode ray tube (2) and unnecessary components such as a flyback transformer (not shown). The radiation source is a housing (3) made of a highly conductive metal plate or a magnetic material, and a heat sink (4).
and a cover (5) to confine the leakage magnetic field inside, thereby reducing the level of unnecessary radiation to the outside.

Conventional unnecessary radiation prevention devices have a structure in which the source of unnecessary radiation is surrounded by a magnetic shielding plate, which not only imposes significant restrictions on the structure of the display device, but also has the problem of poor heat dissipation from the device. Furthermore, there was a problem in that the cost was high.

In order to solve these problems, the applicant filed a patent application in Japanese Patent Application No. 60-232866 for a deflection yoke equipped with an auxiliary coil for canceling unnecessary radiation. The invention related to this earlier application will be explained below with reference to FIGS. 4 and 5.

FIG. 4 is a side view showing the configuration of an embodiment of the earlier-filed invention.
This is a side view showing the deflection yoke attached to the cathode ray tube and the auxiliary coil according to the invention of the prior application, where the auxiliary coil (10) has a winding number of 3 to 10% of the horizontal deflection coil (1b). The front and rear crossing wire portions (lc) and (l
The coil sides (1
0a) and (10b), and this coil side (10
a), (10b) is the crossing line part (lc),
The coil side (toe) extending along (ld) and parallel to the axis is fixed in a posture extending in the axial direction along the outer surface of the core (1a), and when a horizontal deflection current is applied, Leakage magnetic field (l) in the direction shown by the solid arrow in Figure 5
A leakage magnetic field (8a) is generated from the crossover portions (lc) and (ld) of the horizontal deflection coil.

(6b) respectively, and as a result,
Unnecessary radiation level can be reduced.

[Problems to be solved by the invention] However, the auxiliary coil (10) is not connected to the deflection yoke (1).
), due to the structural limitations of the deflection yoke (1), the shape and mounting position of the auxiliary coil (10) are restricted, so it may not be possible to sufficiently suppress unnecessary radiation. There was a problem.

This invention was made to solve these problems, and regardless of the structural limitations of the deflection yoke,
The object of the present invention is to obtain a deflection yoke equipped with an auxiliary coil that can more effectively reduce unnecessary radiation.

Means for Solving Problem c] The deflection yoke according to the present invention includes two sets of auxiliary coils wound in a hollow shape that are substantially similar to the horizontal deflection coil, on each coil side of the horizontal deflection coil. The auxiliary coils are attached to the outside of the deflection yoke in a parallel orientation, and the horizontal deflection current is applied in different directions, and a desired portion of the coil side of each auxiliary coil is covered with a conductive member.

[Function] The two sets of auxiliary coils in this invention are arranged with their respective coil sides almost parallel and generate magnetic fields in opposite directions, so by selecting the parts to be covered with the conductive member, The position, direction, and strength of the magnetic field generated by the auxiliary coil can be adjusted to a distribution pattern suitable for suppressing unnecessary radiation of the deflection yoke, and unnecessary radiation can be effectively reduced.

[Embodiment of the Invention] Fig. 1 is a side view of an embodiment of the invention, in which (12) is a second auxiliary coil, which has almost the same shape as the first auxiliary coil (lO) and has the same number of turns. The first auxiliary coil (10) has a polarity opposite to that of the horizontal deflection coil (lb). generates a leakage magnetic field of
A horizontal deflection current is applied to the auxiliary coil (12) in a direction that generates a forward polarity leakage magnetic field.

(13) is a conductive member such as copper foil, and in this example, the front coil side (12a) of the second auxiliary coil (12).
and the coil side parallel to the axis of the first auxiliary coil (lO) (
10c), respectively, to prevent leakage magnetic fields from being generated from each part. Since the frequency of the horizontal deflection current is generally 15 KHz or more, the auxiliary coil (10) is
, (12) can easily be partially shielded from leaking magnetic flux.

By the way, it is easier to attach the two sets of auxiliary coils (10) and (12) along the outer shape of the deflection yoke (1) as shown in FIG.
This is considered to be the most rational way to reduce deformation of the auxiliary coils (10) and (12) during handling when attaching 1) to the cathode ray (1).

The deflection yoke according to the prior invention shown in Fig. 4 also has an auxiliary coil (10) attached based on this idea, but the distribution of the leakage magnetic field from the deflection yoke (1) is affected by the presence of the core (1a) and the horizontal Due to the complicated shape of the deflection coil (1b) itself, the magnetic field distribution is extremely complicated. Therefore, as in the prior invention, a set of auxiliary coils (lO) formed in a simple hollow shape is used. It was difficult to counteract it effectively by using only one method.

However, as in this embodiment, two sets of auxiliary coils whose generated magnetic fields are in opposite directions are arranged in parallel to the horizontal deflection coil (1b), and conductive members ( 13) by covering the desired portion of the desired coil side with the auxiliary coil (10).

Even if the shape of (12) is a simple hollow shape, a complex magnetic field distribution can be formed, and leakage magnetic fields can be effectively canceled.

In addition, in the above embodiment, the first and second auxiliary coils (10
) and (12) are set to have the same number of turns, but the number of turns may be different depending on the applied deflection yoke.

Furthermore, the two sets of auxiliary coils (to), (12) and the horizontal deflection coil (1b) may be connected in series or in parallel, but one of the auxiliary coils is connected so as to emit a magnetic field of opposite polarity. Must.

[Effects of the Invention] As described above, according to the present invention, the two sets of auxiliary coils wound in a similar shape to the horizontal deflection coil are mounted on the deflection yoke in a posture along the coil side of the horizontal deflection coil. One auxiliary coil is attached to the outside of the auxiliary coil, and a horizontal deflection current is applied so as to generate a magnetic field of opposite polarity to the other auxiliary coil.
By covering with a conductive member, a canceling magnetic field matching the distribution of the leakage magnetic field of the deflection yoke is generated, so that unnecessary radiation of the deflection yoke can be effectively reduced.

[Brief explanation of the drawing]

FIG. 1 is a side view of one embodiment of the present invention, FIG. 2 is a diagram for explaining unnecessary radiation radiated from the deflection yoke, and FIG.
The figure is an exploded perspective view of a conventional unnecessary radiation prevention device, FIG. 4 is a side view of an embodiment of the invention of the prior application by the present applicant, and FIG. 5 is a diagram for explaining its operation. (1)...deflection yoke, (ll))...horizontal deflection coil, (lO)...first auxiliary coil, (12)...
- Second auxiliary coil, (13)... conductive member. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) Two sets of a pair of auxiliary coils formed in a shape similar to the shape of the horizontal deflection coil are attached to the outside in an attitude along each coil side of the horizontal deflection coil, and the two sets of auxiliary coils are The coil is configured to be energized with a horizontal deflection current that is passed through the horizontal deflection coil to generate a magnetic field in the same direction and in the opposite direction to the horizontal deflection coil,
and a deflection yoke in which part of the coil sides of the two sets of auxiliary coils are shielded with a conductive member. (2) The deflection according to claim 1, wherein the two sets of auxiliary coils are connected in series or parallel with the horizontal deflection coil, and the numbers of turns of the two sets of auxiliary coils are different. yoke.