JPH06311377A - Deflection yoke - Google Patents

Abstract

PURPOSE:To make the deflection yoke small by placing a cancel coil to a terminal board of the deflection yoke or a printed circuit board. CONSTITUTION:A drum core 8a of a cancel coil is placed to a front side of a tip of a terminal board 6a fixed to a tail end 5a in the deflection yoke 10a so that a center line is set to a right angle. When a deflection current is supplied to the deflection coil, a magnetic field is generated to deflect an electron beam and a picture is obtained on a screen. In this case, a deflection magnetic field is leaked to the outside of the deflection yoke. The cancel coil generates its magnetic field to cancel the leaked magnetic field. Thus, the size of the cancel coil is made small and the entire deflection yoke is made compact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke for a cathode ray tube.

[0002]

2. Description of the Related Art In a cathode ray tube, that is, a cathode ray tube of a television receiver or a CRT display device, an electron beam emitted from an electron gun built in a neck of a rear portion of the cathode ray tube is deflected in vertical and horizontal directions, and every corner of the screen is displayed. A deflection yoke for correctly transmitting the image is attached to the boundary between the neck and the funnel on the outer surface of the cathode ray tube.

In these deflection yokes, a horizontal deflection current of 15.75 KHz to 120 KHz is normally supplied to the horizontal deflection coil and a vertical deflection current of about 60 Hz is supplied to the vertical deflection coil to generate a horizontal deflection magnetic field from each deflection coil. , The vertical deflection magnetic field is used to deflect the electron beam by a predetermined amount to obtain a desired image on the screen. At this time, both the horizontal deflection magnetic field and the vertical deflection magnetic field generate a leakage magnetic field outside the deflection yoke. . This leakage magnetic field causes electromagnetic interference (E
MI), electromagnetic waves in 5 Hz to 2000 Hz band (ELMF
Wave) and electromagnetic waves (VL) in the 2 KHz to 400 KHz band
With the occurrence of MF wave) obstacles and the like, the need for countermeasures has come to be particularly emphasized recently. As a countermeasure, for example, a cancel coil as disclosed in Japanese Patent Laid-Open No. 63-26928 is attached to the deflection yoke to generate a magnetic field reverse to the leakage magnetic field and cancel it.

[0004]

FIG. 14 is a perspective view of a conventional deflection yoke having a cancel coil.

In FIG. 3, a deflection yoke 10 has horizontal deflection coils 3 and 3 wound in a saddle shape on the inside of a resin bobbin 1 formed in a trumpet shape, and vertical deflection coils 2 and 2 on the outside of the bobbin 1. Similarly, it is wound in a saddle shape. A two-divided core 4 is attached so as to enclose the vertical deflection coils 2 and 2, a tail portion 5 is formed on the small diameter side of the bobbin 1, and a terminal plate 6 is attached to the bobbin 1.

At the opening of the deflection yoke 10 on the screen side, that is, on the large diameter side of the bobbin 1, there are two symmetrically arranged vertically (Y-Y) axes around the tube axis ZZ which is the central axis of the cathode ray tube. The cancel coil 8 is arranged. Note that X
-X indicates the horizontal direction, that is, the horizontal direction. The cancel coil 8 is a closed circuit connected to the horizontal deflection coils 3 and 3 or independent of them.

Conventionally, as the cancel coil 8, there are one in which a coated copper wire is wound in a rectangular shape by a mold and molded, and which is put in a resin case, and wound around a cancel coil core. In any case, winding the coil, attaching it to the deflection yoke in the assembly process, wiring,
Finally, there is a disadvantage that manual work for tying the terminals and the like is required, which makes the assembling work complicated. Further, the shape of the cancel coil is large, and it protrudes outside the wading line of the horizontal deflection coil, which increases the size of the entire deflection yoke. Also,
A structure for attaching the cancel coil 8 to the bobbin 1 of the deflection yoke 10 is required, which complicates the structure of the molding die for the bobbin 1 and increases the die cost.

The present invention has been made in view of the above points, has a simple and small structure, facilitates attachment and wiring to the deflection yoke, and further makes the size of the deflection yoke itself compact. An object of the present invention is to provide a non-bulky deflection yoke including such a cancel coil.

[0009]

In order to solve the above-mentioned problems, the present invention relates to a deflection yoke of a cathode ray tube in which a horizontal deflection coil and a vertical deflection coil are wound around a trumpet-shaped bobbin, and a copper connected to the horizontal deflection coil. A cancel coil formed by winding a wire around a drum core is installed on a terminal plate or a printed board of the deflection yoke.

[0010]

Since the cancel coil formed by winding the copper wire connected to the horizontal deflection coil around the drum core is installed on the terminal plate or the printed board of the deflection yoke, the cancel coil becomes small, and therefore the entire deflection yoke becomes compact. Wiring to the horizontal deflection coil is easy and reliable.

[0011]

1 to 6 are front views showing a schematic structure of a deflection yoke of the present invention, FIGS. 7 and 8 are schematic views of a deflection yoke of the present invention, and FIG. b) is a plan view.

In the embodiment shown in FIGS. 1 to 8, a cancel coil composed of a drum core and a coil wound around the drum core is installed on a terminal plate or a printed circuit board fixed to the tail of the deflection yoke. The direction in which the coil wound around the drum core is connected to the horizontal deflection coil must be such that the magnetic field generated from the drum core cancels the leakage magnetic field of the deflection yoke.

The following can be found from the embodiments shown in these drawings. (1) As shown in FIGS. 1 to 5, the cancel coil may be installed anywhere on the surface of the terminal board or the printed board. (2) As shown in FIGS. 6 to 8, any number of cancel coils may be installed. (3) As shown in FIGS. 1 to 3 and 8, the attachment angle of the drum core of the cancel coil to the deflection yoke may be arbitrary. (4) When mounting a plurality of drum cores, as shown in FIGS.

An embodiment of each drawing will be described.

In the deflection yoke 10a shown in FIG. 1, the drum core 8 of the cancel coil is attached to the surface of the tip portion of the terminal plate 6a fixed to the tail portion 5a.
a (and the coil) are installed with their center lines at right angles.

In the deflection yoke 10b shown in FIG. 2, with respect to the surface of the terminal plate 6b fixed to the tail portion 5b,
The drum core 8b (and the coil) of the cancel coil is installed with its center lines parallel.

In the deflection yoke 10c shown in FIG. 3, the drum core 8c (and coil) of the cancel coil is installed with its center line at a right angle to the surface of the terminal plate 6c fixed to the extension of the tail 5c. ing.

In the deflection yoke 10d shown in FIG. 4, the drum core 8 of the cancel coil is attached to the surface of the root portion of the terminal plate 6d fixed to the tail portion 5d.
d (and the coil) are installed with their center lines at right angles.

In the deflection yoke 10e shown in FIG. 5, with respect to the rear surface of the terminal plate 6e fixed to the tail portion 5e,
The drum core 8d (and the coil) of the cancel coil is installed with its center line at a right angle.

In the deflection yoke 10f shown in FIG. 6, the drum core 8f (and the coil) of the canceling coil has its center line on the surface at the tips of the two terminal plates 6f fixed to the tail 5f. It is installed at a right angle.

Deflection yoke 10 shown in FIGS. 7 (a) and 7 (b).
6g, terminal plate 6g fixed to its tail 5g
At the tip of the, the two drum cores 8g (and the coils) of the two canceling coils are installed on the surface in a direction perpendicular to the center axis and perpendicular to the tube axis.

The deflection yoke 10 shown in FIGS. 8 (a) and 8 (b).
terminal plate 6h fixed to its tail 5h
At the front end of the, the two drum cores 8h (and the coils) of the two cancel coils are installed on the surface thereof with their center lines at right angles and aligned in the tube axis direction.

The deflection yoke of the present invention having the above structure operates as follows.

When a deflection current is supplied to the deflection coil, a magnetic field is generated from the deflection coil, and the electron beam can be deflected by these magnetic fields to obtain an image on the screen. At this time, the deflection magnetic field generates a leakage magnetic field outside the deflection yoke. The cancel coil generates a magnetic field in a direction that cancels this leakage magnetic field.

The method of measuring the canceling effect of the cathode ray tube having the deflection yoke of the present invention and the measurement results will be described.

Measuring Conditions FIG. 9 is a front view showing a schematic configuration of a canceling effect measuring device, FIG. 10 is a plan view for explaining measurement points of leakage magnetic flux of a cathode ray tube, and FIG. 11 is a circuit diagram of a deflection yoke of the present invention. .

The cancel coil, which is a coil formed by winding a copper wire around the drum core 8c 15 times, is placed in the state shown in FIG.
The cancel yoke coil is connected in series to two horizontal deflection coils which are attached to c and are connected in parallel as shown in the circuit diagram of FIG. 11 to form the deflection yoke 10c of the present invention. This deflection yoke 10c is attached to the cathode ray tube 11,
Place it horizontally on the upper surface of the universal set 12 and set the H
Points C and H are points H of the measuring circuit of universal set 12,
Connect to point C (Fig. 9).

As shown in FIG. 10, on the horizontal plane H passing through the center of the front surface 13 of the cathode ray tube 11 and the horizontal planes H 1 and H 2 at positions vertically above and below the center, as shown in FIG. With the reference position at a distance of 50 from 0, a total of 24 three-dimensionally arranged measurement points were set on the horizontal circumference at intervals of 45 degrees, and the leakage magnetic flux at these measurement points was measured. .

Measurement Results FIG. 12 is a graph showing leakage flux measurement data of a cathode ray tube having a deflection yoke of the present invention, and FIG. 13 is a graph showing leakage flux measurement data of a cathode ray tube having a deflection yoke from which a cancel coil is removed. is there.

FIGS. 12 and 13 show leakage magnetic flux data at 24 measurement points obtained under the above measurement conditions on one graph in the unit of nT (nano Tesla). The thick solid line is M with 25 nT as the reference value.
The PR- standard is shown, and the thin solid line is the measured value on the horizontal plane H 1, the dotted line is the measured value on the horizontal plane H 1, and the chain line is the measured value on the horizontal plane H 2. Comparing the graphs of FIGS. 12 and 13, the leakage flux measurement value of the cathode ray tube having the deflection yoke of the present invention of FIG. 12 is almost close to the reference value.
It is clear that the canceling coil of No. 3 is smaller than the value when there is no canceling coil, and the canceling coil cancels the leakage magnetic flux.

[0031]

As described above, in the deflection yoke of the present invention, the cancel coil formed by winding the copper wire connected to the horizontal deflection coil around the drum core is installed on the terminal plate or the printed board of the deflection yoke. Therefore, the following excellent effects can be obtained. (1) The cancel coil is small, so that the entire deflection yoke is compact. (2) The leakage magnetic field generated outside the deflection yoke can be canceled by the deflection magnetic field. (3) When mounting various electric parts on the deflection yoke,
Since a cancel coil can be mounted at the same time,
Work cost is reduced. (4) When the cancel coil is installed on the printed circuit board, the wiring between the copper wire of the drum core and the horizontal deflection coil is not the aerial wiring as in the conventional case, and reliable wiring can be performed through the printed circuit board. (5) The structure of the bobbin molding die is simplified and the die cost is reduced.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a deflection yoke of the present invention.

FIG. 2 is a front view showing a schematic configuration of a deflection yoke of the present invention.

FIG. 3 is a front view showing a schematic configuration of a deflection yoke of the present invention.

FIG. 4 is a front view showing a schematic configuration of a deflection yoke of the present invention.

FIG. 5 is a front view showing a schematic configuration of a deflection yoke of the present invention.

FIG. 6 is a front view showing a schematic configuration of a deflection yoke of the present invention.

FIG. 7 is a diagram showing a schematic configuration of a deflection yoke of the present invention,
(A) is a front view and (b) is a plan view.

FIG. 8 is a diagram showing a schematic configuration of a deflection yoke of the present invention,
(A) is a front view and (b) is a plan view.

FIG. 9 is a front view showing a schematic configuration of a cancellation effect measuring device.

FIG. 10 is a plan view illustrating measurement points of leakage magnetic flux of a cathode ray tube.

FIG. 11 is a circuit diagram of a deflection yoke of the present invention.

FIG. 12 is a graph showing leakage magnetic flux measurement data of a cathode ray tube having a deflection yoke of the present invention.

FIG. 13 is a graph showing measurement data of leakage magnetic flux of a cathode ray tube having a deflection yoke from which a cancel coil is removed.

FIG. 14 is a perspective view of a deflection yoke having a conventional cancel coil.

[Explanation of symbols]

 1 Bobbin 2 Vertical Deflection Coil 3 Horizontal Deflection Coil 5a-5h Tail 6a-6h Terminal Plate 8a-8h Cancel Coil Drum Core 10a-10h Deflection Yoke 11 Cathode Ray Tube 1120 Universal Set 13 Front Side of Cathode Ray Tube

[Procedure amendment]

[Submission date] April 5, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

On the horizontal plane H ₂ passing through the center of the front surface 13 of the cathode ray tube 11 and the horizontal planes H ₁ and H ₃ at positions 300 mm above and below the center, as shown in FIG. Set a total of 24 three-dimensional measurement points on the horizontal circumference at a distance of 45 degrees from the front surface 13 at a distance of 50 cm from the front surface 13 at a distance of 45 degrees, and leak magnetic flux at these measurement points. Was measured.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

FIGS. 12 and 13 show leakage magnetic flux data at 24 measurement points obtained under the above measurement conditions on one graph in the unit of nT (nano Tesla). The thick solid line is M with 25 nT as the reference value.
The PR-II standard is shown, and the thin solid line is the measured value on the horizontal plane H ₁ , the dotted line is the measured value on the horizontal plane H ₂ , and the chain line is the measured value on the horizontal plane H ₃ . Comparing the graphs of FIGS. 12 and 13, the leakage flux measurement value of the cathode ray tube having the deflection yoke of the present invention of FIG. 12 is almost close to the reference value.
It is clear that the canceling coil of No. 3 is smaller than the value when there is no canceling coil, and the canceling coil cancels the leakage magnetic flux.

Claims (1)

[Claims] 1. A deflection yoke of a cathode ray tube comprising a trumpet-shaped bobbin wound with a horizontal deflection coil and a vertical deflection coil,
A deflection yoke, wherein a cancel coil formed by winding a copper wire connected to the horizontal deflection coil around a drum core is installed on a terminal plate of the deflection yoke or a printed board.