JPH04154027A - Deflection yoke device - Google Patents

Abstract

PURPOSE:To effectively cancel the leakage magnetic field leaked from a horizontal deflection coil by protrusively providing a leakage magnetic field inhibiting coil situated on the top part of a deflection yoke, almost at right angle to the end surface of the top part. CONSTITUTION:A leakage magnetic field inhibiting coil 3 for cancelling a leakage magnetic field leaked from the horizontal deflection coil of a deflection yoke 1, is put on either/both of the top side or/and the bottom side of the top 2 side of the deflection yoke 1, and the coil is protrusively provided at almost right angle to the end surface of the top 2 of the deflection yoke 1, in the direction of a neck side. When the deflection yoke 1 is driven, the leakage magnetic field is pulled out of the horizontal deflection coil to the top side as well as the bottom side of the deflection yoke 1, however, the leakage magnetic field is offset by a cancel magnetic field in the reverse direction generated from the cancel coil 3, and is thus reduced. The leakage magnetic field generated from the horizontal deflection coil can thus be effectively offset by using a small leakage magnetic field inhibiting coil 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a deflection yoke device equipped with means for canceling a leakage magnetic field leaking from a horizontal deflection coil.

[Conventional technology]

As is well known, a deflection yoke used in cathode ray tubes of television receivers and display devices includes a horizontal deflection coil and a vertical deflection coil.

Recently, 2KHz ~ leaking from the horizontal deflection coil
Reports have been published one after another that low frequency leakage magnetic fields of 400KHz have an adverse effect on the human body, and the conclusion as to whether low frequency leakage magnetic fields are harmful or harmless to the human body is not yet definitive.
Measures are being taken to prevent this.

FIG. 5 shows a deflection yoke device equipped with this type of low frequency leakage magnetic field canceling means.

This deflection yoke device has a pair of leakage magnetic field prevention coils 3 on the top side and bottom side of the head 2 side of the deflection yoke l.
The deflection yoke 1 protrudes toward the neck side of the deflection yoke 1 with an oblique angle θ (an angle smaller than 90 degrees) with respect to the end face of the deflection yoke 1. This leakage magnetic field prevention coil 3 has a coil wound in a ring shape housed in a coil bobbin 4, and the coil bobbin 4 is fixed to the head 2 of the deflection yoke l via an angle 5 by engagement adhesive or the like. There is.

This leakage magnetic field prevention coil 3 is wound in a direction that generates a canceling magnetic field in the opposite direction to the leakage magnetic field leaking from the horizontal deflection coil, and the lead of the coil is connected to the horizontal deflection coil, so that the horizontal deflection current prevents the leakage magnetic field. By flowing through the coil 3, a canceling magnetic field is generated from the leakage magnetic field prevention coil 3, and the leakage magnetic field generated from the horizontal deflection coil is canceled and reduced by the canceling magnetic field generated from the leakage magnetic field prevention coil 3. This eliminates concerns about negative effects on the human body.

[Problem to be solved by the invention]

However, since the conventional leakage magnetic field prevention coil 3 is installed diagonally at an angle θ with respect to the head end surface of the deflection yoke 1, it is difficult to accurately adjust the diagonal angle θ, which prevents the leakage magnetic field. There is a problem that the workability of attaching the coil 3 becomes worse. Furthermore, since the leakage magnetic field prevention coil 3 is installed at an oblique angle, the mechanical strength of the joint (bent portion) of the leakage magnetic field prevention coil 3 to the deflection yoke 1 is weakened, making it easy for damage to occur from that part. There was a problem.

Furthermore, in the method in which the leakage magnetic field prevention coil 3 is attached obliquely to the deflection yoke l, the leakage magnetic field prevention coil 3
The deflection yoke 1 protrudes outward from the deflection yoke l, which poses a problem of increasing the size of the deflection yoke device. here,
As a means of solving the problem of increasing the size of the deflection yoke device, it is possible to reduce the shape of the leakage magnetic field prevention coil 3. Even if the shape of the leakage magnetic field prevention coil 3 is made small, the leakage magnetic field can be effectively canceled. However, as described above, problems still arise due to the installation of the leakage magnetic field prevention coil 3 at an oblique angle.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to improve the workability of attaching the leakage magnetic field prevention coil to the deflection yoke, and to improve the mechanical strength of the joint. It is an object of the present invention to provide a deflection yoke device which can increase the height of the magnetic field and further reduce the size of the leakage magnetic field prevention coil.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, in the deflection yoke device of the present invention, the leakage magnetic field prevention coil for canceling the leakage magnetic field leaking from the horizontal deflection coil of the deflection yoke is located on at least one side of the top side and the bottom side of the head side of the deflection yoke. It is characterized in that it protrudes toward the neck while keeping an angle substantially perpendicular to the end surface of the head.

[Effect]

In the present invention, when the deflection yoke is driven, a leakage magnetic field is emitted from the horizontal deflection coil to the top and bottom sides of the deflection yoke, but this leakage magnetic field is canceled out and reduced by the canceling magnetic field in the opposite direction generated from the canceling coil.

In the present invention, since the leakage magnetic field prevention coil is located on the head side of the deflection yoke and protrudes almost perpendicularly to the head end surface, the leakage magnetic field emitted from the horizontal deflection coil is suppressed using a small leakage magnetic field prevention coil. can be effectively canceled out.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. In the description of this embodiment, the same parts as those of the conventional example shown in FIG. 5 are denoted by the same reference numerals, and detailed redundant explanation thereof will be omitted.

In the first part, an external configuration of an embodiment of a deflection yoke device according to the present invention is shown. The characteristic feature of this embodiment that is different from the conventional example is that the leakage magnetic field prevention coil 3 attached to at least one of the top side and bottom side of the deflection yoke l is attached to the end surface of the head 2 on the head 2 side of the deflection yoke l. This means that it was installed at an almost right angle. Normally, the bobbin 6, core 7, and vertical deflection coil 8 of the deflection yoke 1 are fixed with a thermoplastic hot melt adhesive 10, and this hot melt adhesive lO is applied to the back surface 6a of the head 2 of the bobbin 6. In this embodiment, a leakage magnetic field prevention coil 3 is installed on the outer side of the rib 11 at right angles to the head end surface of the deflection yoke 1, using the rib 11 as a guide. The base side is fixed to the back surface 6a of the head of the bobbin 6 using an appropriate fixing means such as adhesive, and the tip side of the leakage magnetic field prevention coil 3 is fixed to the deflection yoke l.
It protrudes toward the neck side.

If the bobbin 6 of the deflection yoke l is of the type in which the rib 11 is not formed, a short jig is used so that the leakage magnetic field prevention coil 3 is oriented perpendicular to the head end surface of the deflection yoke 1. The leakage magnetic field prevention coil 3 is mounted so as to be aligned perpendicularly to the head end surface of the deflection yoke 1. In this case, the bottom surface 3 of the leakage magnetic field prevention coil 3
If a is made flat, the leakage magnetic field prevention coil 3 can be prevented by contacting the bottom surface 3a with the back surface 6a of the bobbin 6 on the head side.
can be automatically oriented perpendicular to the back surface 6a of the bobbin head, and the mounting angle of the leakage magnetic field prevention coil 3 can be easily set to 90 degrees.

In this embodiment, the leakage magnetic field prevention coil 3 is formed into a rectangular shape, as shown in FIG.

This rectangular coil may be formed by winding the wire into a rectangular ring shape, but in this embodiment, the coil wound into a rectangular ring shape is housed in a rectangular box-shaped coil bobbin 4. It is formed as follows. This leakage magnetic field prevention coil 3 is attached to the deflection yoke 1 and connected in series to the horizontal deflection coil with the polarity set in a direction to cancel the leakage magnetic field emitted from the horizontal deflection coil.

3 and 4 show an experimental example of the canceling effect of the leakage magnetic field prevention coil 3 on the leakage magnetic field in this embodiment. In this experimental example, the deflection yoke 1 is attached to a cathode ray tube, and while the cathode ray tube is rotated at intervals of 22° and 5°, the leakage magnetic field from the deflection yoke 1 at each rotational angular position is transmitted to the tube 50C11 away from the screen of the cathode ray tube. Measured at the axial position. Note that the leakage magnetic field prevention coil 3 is a coil wound with 15 turns, and the experiment was conducted with one coil 3 attached only to the top side of the deflection yoke.

The pie chart in Figure 3 compares the canceling effect with respect to the size of the leakage magnetic field prevention coil 3, and the line to indicates the magnitude of the leakage magnetic field when no leakage magnetic field prevention coil is provided. The line B shows the measurement results of the leakage magnetic field when equipped with the conventional large-scale leakage magnetic field prevention coil shown in FIG.
The line D shows the first measurement result of this example in which a rectangular leakage magnetic field prevention coil 3 with a width W of 80 mm is attached at right angles to the back surface of the head of the deflection yoke 1. 2 shows the second measurement results of this example in which a rectangular leakage magnetic field prevention coil 3 with a length H of 15 mm and a width W of 50 mm shown in FIG. 2 is attached. As is clear from this experimental result, the results shown in C and D of this example are different from those shown in B of the conventional example.
When compared with the results shown in , it can be seen that the leakage magnetic field canceling effect of this example is significantly improved compared to the conventional example. Furthermore, as can be seen by comparing the experimental results C and D of this example, even if the size of the leakage magnetic field prevention coil 3 is reduced, a good canceling effect of the leakage magnetic field can be obtained, and the coil 3 can be made more compact. It is understood that this can be achieved.

The graph shown in FIG. 4 shows a comparison result of the angle at which the leakage magnetic field prevention coil 3 is attached to the head end surface of the deflection yoke 1. In this FIG. 4, the line A shows the measurement results of the leakage magnetic field when the leakage magnetic field prevention coil 3 is not provided.
In Fig. 2, the line E shows the leakage magnetic field prevention coil 3 with H of 15 ma+ and W of 80 mm placed at 7.
This shows the case where it is installed on the top side at a 0 degree angle.
The line F indicates a leak of the same size with respect to the head end face of deflection yoke 1!
! ! This example shows the case where the magnetic field prevention coil 3 is attached at an angle of 90 degrees. As can be seen from the experimental results shown in FIG. 4, it can be seen that by attaching the leakage magnetic field prevention coil 3 at 90 degrees as in this embodiment, the effect of canceling the leakage magnetic field can be more effectively exhibited. In the above experimental example, the leakage magnetic field prevention coil 3 was provided only on the top side of the deflection yoke 1, but if the same coil 3 was also provided on the bottom side of the deflection yoke 1, the leakage magnetic field canceling effect would be even greater than in the experimental example. It will be elevated.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may take various embodiments.For example, in the above-mentioned embodiments,
Although the leakage magnetic field prevention coil 3 is provided on both the top and bottom sides of the head side of the deflection yoke, it may be provided on only one side depending on the strength of the leakage magnetic field. It is. Further, in the above embodiment, the leakage magnetic field prevention coil 3 is formed into a rectangular shape, but the coil shape may be formed into any shape such as a square, circle, ellipse, triangle, or rhombus.

Further, in the above embodiment, the leakage magnetic field prevention coil 3 is connected to the horizontal deflection coil, but for example, a separate and independent power source is provided, and this power source supplies the leakage magnetic field prevention coil 3 with a current synchronized with the horizontal deflection current. You can do it like this. Furthermore, in the above embodiment, a deflection yoke device is described in which the vertical deflection coil is wound in a hollow shape in the drawings, but a deflection yoke device in which the vertical deflection coil is wound in a toroidal manner around the core is also applicable. Of course, it can be applied.

〔Effect of the invention〕

In the present invention, the leakage magnetic field prevention coil is located on the head side of the deflection yoke and is provided to protrude almost perpendicularly to the end surface of the head. Compared to the case where the angle is adjusted by 90 degrees, it is much easier to adjust the angle by 90 degrees, and the workability of attaching the leakage magnetic field prevention coil to the deflection yoke can be greatly improved.

In addition, by attaching the leakage magnetic field prevention coil at right angles, the base side of the leakage magnetic field prevention coil can be firmly fixed to the deflection yoke, thereby increasing the mechanical strength of the leakage magnetic field prevention coil installation. can,
It is possible to eliminate the risk of damage to the joint to the deflection yoke.

Furthermore, by protruding the leakage magnetic field prevention coil in a direction perpendicular to the head end face of the deflection yoke, the leakage magnetic field leakage from the horizontal deflection coil can be effectively canceled while the leakage magnetic field prevention coil is formed compactly. This makes it possible to downsize the deflection yoke device equipped with the leakage magnetic field prevention coil.

[Brief explanation of the drawing]

Fig. 1 is an external configuration diagram showing an embodiment of the deflection yoke device according to the present invention, Fig. 2 is an explanatory diagram of a leakage magnetic field prevention coil constituting the embodiment, and Figs. 3 and 4 are the same embodiment. A graph showing an experimental example of the leakage magnetic field prevention effect of the device, and FIG. 5 is an explanatory diagram of a conventional deflection yoke device provided with a leakage magnetic field prevention coil. DESCRIPTION OF SYMBOLS 1... Deflection yoke, 2... Head, 3... Leakage magnetic field prevention coil, 3a... Bottom surface, 4... Coil bobbin,
5...Installation angle, 6...Bobbin, 7...
- Core, 8... Vertical deflection coil, 10... Honmelt adhesive side, 11... Rib. Applicant Murata Manufacturing Co., Ltd. Representative Patent Attorney Igarashi Seihoki! Bacterial hand intoxication No. 7 (He7/j) -3 Diagram〉T・S7 Mereri

Claims (1)

[Claims] A leakage magnetic field prevention coil for canceling the leakage magnetic field leaking from the horizontal deflection coil of the deflection yoke is located on at least one side of the top side and the bottom side of the head side of the deflection yoke, and is arranged almost perpendicularly to the head end surface of the deflection yoke. A deflection yoke device that maintains an angle and protrudes toward the neck side.