JP3334379B2 - Deflection yoke - Google Patents

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 improving the deflection sensitivity and can be applied to a cathode ray tube device such as a computer display device.

[0002]

2. Description of the Related Art Conventionally, in a deflection yoke, in a cathode ray tube device, a deflection center is set so that neck shadow does not occur, and the entire length is determined substantially by the deflection center.

That is, in this type of deflection yoke, a pair of horizontal deflection coils are arranged vertically so as to sandwich the neck of the cathode ray tube, and a horizontal deflection magnetic field crossing the neck of the cathode ray tube vertically by the pair of horizontal deflection coils. It is formed. In addition, a pair of vertical deflection coils are arranged on the left and right of the deflection yoke from outside the horizontal deflection coil so as to sandwich the neck of the cathode ray tube, and the pair of vertical deflection coils vertically traverse the neck of the cathode ray tube left and right. A magnetic field is formed.

Further, in the deflection yoke, a substantially conical cylindrical core is arranged outside the vertical deflection coil, and the core forms a magnetic circuit for the horizontal deflection coil and the vertical deflection coil. As a result, in the deflection yoke, the magnetic lines of force crossing the neck of the cathode ray tube are formed so as to circumvent the core and return to the original deflection coil, so that the leakage magnetic field can be reduced and electromagnetic deflection can be performed efficiently.

In the cathode ray tube apparatus, the horizontal deflection coil and the vertical deflection coil are driven to electromagnetically deflect the electron beam emitted from the electron gun, and the electron beam is raster-scanned. That is, when the electron beam emitted from the electron gun passes through the deflecting magnetic field, the scanning trajectory is bent and deflected up and down and left and right of the cathode ray tube, and then goes straight on the funnel portion of the cathode ray tube toward the front.

Therefore, in the cathode ray tube device, if this deflection center (ie, corresponding to the center of the magnetic field distribution of the deflection magnetic field) is set too close to the electron gun, the electron beam emitted toward the corner of the display screen will be During the run,
It collides with the inner wall surface of the neck, which obstructs the traveling of the electron beam at the corners and causes neck shadow.

For this reason, in the deflection yoke, the length of the deflection coil is extended to the front side of the cathode ray tube in comparison with the length of the neck of the cathode ray tube, whereby the deflection center is located at a predetermined position or more on the front side of the cathode ray tube. It is set to effectively avoid neck shadows.

[0008]

When the center of deflection is set on the front side of the cathode ray tube as described above, it is necessary to increase the deflection angle accordingly, and for this purpose, it is necessary to increase the deflection magnetic field. Therefore, if the deflection center can be shifted to the electron gun side, the deflection angle can be reduced accordingly, the deflection magnetic field can be reduced, the power consumption can be reduced, and the temperature rise of the deflection yoke can be reduced. it can.

Focusing on this, the central portion of the display screen of the cathode ray tube apparatus has a feature that no neck shadow occurs at the central portion of the display screen even if the deflection center is shifted to the electron gun side. . Therefore, in the deflection yoke, if the neck shadow at the corner portion can be effectively avoided, the deflection center can be shifted to the electron gun side and the deflection sensitivity can be improved accordingly.

When the deflection coil is extended to the front side of the cathode ray tube, the diameter of the cathode ray tube increases from the neck toward the funnel, so that the front end diameter of the deflection yoke must be increased accordingly. Therefore, in the deflection yoke, if the deflection center can be shifted to the electron gun side, the overall shape can be reduced in size and the weight can be reduced accordingly.

The present invention has been made in view of the above points, and effectively avoids neck shadows at corners.
It is an object of the present invention to propose a deflection yoke which can improve the deflection sensitivity as compared with the related art and can reduce the size.

[0012]

According to the present invention, there is provided a cathode ray tube which is held by a neck of a cathode ray tube.
In a deflection yoke for electromagnetically deflecting a cathode ray tube, a pair of horizontal deflection coils which are held opposite to each other with a neck of the cathode ray tube therebetween and form a horizontal deflection magnetic field, and a horizontal deflection coil is provided on the electron gun side of the horizontal deflection coil. A part of the horizontal deflection current is modulated by a vertical deflection current so as to form a magnetic field of the sub coil in a direction to cancel the magnetic field formed by the sub coil arranged in correspondence with the deflection coil and the horizontal deflection coil. A modulation circuit for supplying the sub coil.

In particular, the modulation circuit is formed of a saturable reactor having a primary winding and a secondary winding, supplies a vertical deflection current to the primary winding, and connects the secondary winding in series with the subcoil. And connected in parallel with the horizontal deflection coil.

[0014]

A sub-coil is provided so as to correspond to the horizontal deflection coil, and a part of the horizontal deflection current is supplied to the sub-coil so that the magnetic field of the sub-coil is formed in a direction to cancel the magnetic field formed by the horizontal deflection coil. If supplied by modulating with the deflection current, the sub-coil generates a magnetic field in the direction to cancel the horizontal deflection magnetic field when deflecting the vicinity of the upper and lower ends of the display screen, and in the deflection magnetic field, from the electron gun side to the display screen side. The magnetic field distribution moves.

In particular, if the modulation circuit is formed by a saturable reactor having a primary winding and a secondary winding, the saturable reactor is set to be saturated when the vertical deflection current increases, and the display screen is displayed. When deflecting near the upper and lower ends, a magnetic field can be generated in a direction to cancel the horizontal deflection magnetic field.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a side view showing a deflection yoke according to an embodiment of the present invention, with a partial cross section. 2, only the horizontal deflection coil 7 and the like are described on the cross-sectional side, and description of other components is omitted. Here, in the deflection yoke 1, in the assembly process, after the horizontal deflection coil assembly 2 and the vertical deflection coil assembly 3 are combined, the core 4 is attached from the outside, and then the front cover 5 and the back cover 6 are attached. It is formed.

The core 4 is disposed outside the vertical deflection coil 8 by combining two ferrite cores so as to form a substantially conical cylindrical ring core. As a result, the core 4 forms a magnetic circuit of a horizontal deflection magnetic field and a vertical deflection magnetic field, so that the deflection yoke can efficiently perform electromagnetic deflection.

The vertical deflection coil assembly 3 is formed by winding a vertical deflection coil 8 around a separator forming a coil bobbin in a vertical winding step. The vertical deflection coil 8 is formed in a saddle shape by section winding. When the deflection yoke 1 is arranged on the cathode ray tube, the vertical deflection coil 8 is disposed outside the horizontal deflection coil assembly 2 so as to sandwich the neck of the cathode ray tube from left and right. 4 inside. Thereby, the vertical deflection coil 8 forms a vertical deflection magnetic field that crosses the neck of the cathode ray tube left and right.

On the other hand, the horizontal deflection coil assembly 2 is formed by winding a horizontal deflection coil 7 around a separator forming a coil bobbin in a horizontal winding step. At this time, the horizontal deflection coil 7 winds a prescribed magnet wire using the inner side surface of the separator and the projections formed on the front end surface and the rear end surface, thereby forming a saddle shape by section winding. The horizontal deflection coil 7 is
When the deflection yoke 1 is arranged on the cathode ray tube, the deflection yoke 1 is arranged inside the vertical deflection coil assembly 3 so as to sandwich the neck of the cathode ray tube from above and below. Thereby, the horizontal deflection coil 7 forms a horizontal deflection magnetic field that crosses the neck of the cathode ray tube up and down.

As further shown in FIG. 3, in this embodiment, the horizontal deflection coil assembly 2 is mounted on the electron gun side.
The sub-coil 9 is arranged, and in the deflection yoke 1, the deflection center moves to the display screen side near the upper and lower ends of the display screen by the sub-coil 9. In FIG. 3, a horizontal deflection coil formed by section winding is shown in a simplified manner.

That is, the sub-coil 9 is formed by winding a magnet wire formed of a self-fusing wire in a predetermined mold and then self-fusing the sub-coil 9 in an arc shape along the neck of the cathode ray tube and viewed from above. At this time, the magnet wire is formed so as to run in a rectangular shape. The horizontal deflection coil assembly 2 has a recess formed on the outer side surface of the separator,
After positioning the sub-coil 9 using the concave portion, the sub-coil 9 is fixed to the separator with a tape or the like. This allows the horizontal deflection coil assembly 2 to easily and reliably mount the sub coil 9.

At this time, the horizontal deflection coil assembly 2
Holds two sub-coils 9 so as to correspond to the horizontal deflection coil 7 held so as to face each other with the neck of the cathode ray tube interposed therebetween. Thereby, the horizontal deflection coil assembly 2 moves the sub-coil 9 to the rear end side of the horizontal deflection coil 7 (that is, to the electron gun side) so that the horizontal deflection magnetic field interlinks and corresponds to the horizontal deflection coil 7. Deploy.

The deflection yoke 1 connects the lead lines of the sub coil 9 to the lead lines of the horizontal deflection coil 7 and the vertical deflection coil 8 on a terminal plate arranged on the back cover 6 side of the deflection yoke 1. Thereby, the deflection yoke 1
Supplies a part of the horizontal deflection current to the sub-coil 9 and varies the amount of the horizontal deflection current supplied to the sub-coil 9 in accordance with the vertical deflection current. Move to

That is, as shown in FIG. 4, in this embodiment, a pair of horizontal deflection coils 7 are connected in parallel to supply a horizontal deflection current IH, and similarly, a pair of vertical deflection coils 8 are connected in parallel. Then, a vertical deflection current IV is supplied. After the pair of sub-coils 9 are connected in series, they are connected in series with the secondary winding of the saturable reactor 10, and this series circuit is connected in parallel with the horizontal deflection coil 7. Thus, a part of the horizontal deflection current IH is supplied to the sub coil 9 via the saturable reactor 10. At this time, the sub coil 9 is connected to the horizontal deflection coil 7 so as to form a magnetic field having a polarity opposite to that of the horizontal deflection magnetic field formed by the horizontal deflection coil 7.

The saturable reactor 10 is formed by winding a primary winding and a secondary winding around a prescribed magnetic circuit, and the primary winding is connected in series to a vertical deflection coil 8 connected in parallel. It has been made. Thereby, the saturable reactor 1
0 is selected so that the vertical deflection current IV is supplied to the primary winding, and when the vertical deflection current IV increases and deflects near the upper and lower ends of the display screen, the magnetic circuit is saturated. Have been.

Thus, in the saturable reactor 10, near the upper and lower ends of the display screen, the impedance is reduced by the vertical deflection current IV, and the amount of the horizontal deflection current IH flowing through the sub-coil 9 is increased. Therefore, the saturable reactor 10 generates a magnetic field due to the horizontal deflection current IH to further bring the magnetic circuit closer to saturation, so that the horizontal deflection current amount of the sub-coil 9 increases at the corner of the display screen. The impedance of the next winding will change.

Therefore, as shown in FIG. 1, the sub-coil 9 is arranged at the rear end of the horizontal deflection coil 7 (FIG. 1).
(A)) and by connecting the horizontal deflection coil 7 so as to form a magnetic field of the opposite polarity, the magnetic field ΦS (FIG. 1 (B)) generated by the sub-coil 9 is close to the upper and lower ends of the display screen. The main magnetic field ΦM (FIG. 1C) formed by the horizontal deflection coil 7 is formed on the electron gun side so as to reduce the main magnetic field ΦM.

As a result, the deflection magnetic field applied to the cathode ray tube is represented by a combined magnetic field .PHI.T obtained by combining the two magnetic fields .PHI.M and .PHI.S (FIG. 1 (D)). The magnetic field distribution of the synthetic magnetic field ΦT changes, and the magnetic field center O2 of the synthetic magnetic field ΦT is on the display screen side by an amount L that is smaller than the magnetic field center O1 of the main magnetic field ΦM on the electron gun side of the main magnetic field ΦM. Will move.

Thus, in the deflection yoke 1, the center of deflection can be moved to the display screen side near the upper and lower ends, and the margin for the neck shadow near the upper and lower ends can be improved. As a result, in the deflection yoke 1, the deflection sensitivity can be improved, and the size and weight can be reduced because the allowance of the vicinity of the upper and lower ends with respect to the neck shadow is increased.

Thus, in the deflection yoke 1, the horizontal deflection coil 7 and the vertical deflection coil 8 are deflected so that the original deflection center moves to the electron gun side by the increased margin near the upper and lower ends with respect to the neck shadow. By moving the positions of the display screen side and the end face of the yoke 1 toward the electron gun, the overall length is reduced, and accordingly, the overall length of the components such as the separator and the front cover 5 is also reduced. , Or a small size.

By the way, in this embodiment, when the change in the magnetic field strength of the entire deflection magnetic field is observed before and after the saturable reactor 10 is saturated, it is found that the deflection after deflection is greater than before the saturation. The change in the magnetic field strength becomes smaller with respect to the change in the current. That is, in the deflection yoke 1, the change in the magnetic field intensity is smaller in the vicinity of the upper and lower ends than in the other portions with respect to the change in the deflection current.

Considering this and the fact that the center of deflection moves to the display screen side, the deflection yoke 1 has a raster-shaped barrel shape as compared with the conventional deflection yoke. Become. On the other hand, in the conventional deflection yoke, pin distortion cannot be avoided, and therefore, a pin distortion correction mechanism such as a pin distortion correction magnet is provided. Thus, according to the deflection yoke 1 of this embodiment, it is understood that the pin distortion can be reduced. According to the results of the experiment, it was confirmed that the pin distortion can be completely neglected depending on the driving conditions for the left and right pin distortion.

In the above arrangement, the deflection magnetic field formed by the horizontal deflection coil 7 and the vertical deflection coil 8 crosses the tube axis of the cathode ray tube up and down and left and right, and then turns around the core 4 substantially half a turn. Returning to the horizontal deflection coil 7 and the vertical deflection coil 8, when the polarity of the deflection current is reversed, it follows the reverse path. This deflection magnetic field changes following the change of the deflection current, so that the deflection yoke 1
The electron beam emitted from the electron gun is electromagnetically deflected.

At this time, a part of the horizontal deflection current IH is supplied to the sub-coil 9 arranged on the electron gun side of the horizontal deflection coil 7 so as to correspond to the horizontal deflection coil 7 so that the deflection yoke 1 A magnetic field ΦS is formed in a direction to cancel the main magnetic field ΦM formed by the deflection coil 7. Further, the horizontal deflection current IH supplied to the magnetic field ΦS is modulated by the saturable reactor 10 so as to increase at the upper and lower ends of the display screen, so that the magnetic field ΦS becomes stronger at the upper and lower ends of the display screen. Formed.

As a result, at the deflection center of the deflection yoke 1, near the center of the display screen, the horizontal deflection coil 7
Is held at the deflection center O1 of the main magnetic field .PHI.M formed on the other hand, while it moves toward the display screen by the magnetic field .DELTA.S of the sub-coil 9 in the vicinity of the upper and lower ends. Degree near the upper and lower ends,
The deflection sensitivity can be increased, and the size and weight can be reduced.

According to the above arrangement, the sub-coil is arranged on the electron gun side of the horizontal deflection coil so as to correspond to the horizontal deflection coil, and a part of the horizontal deflection current is modulated by the vertical deflection current to be applied to the sub-coil. By supplying and forming a magnetic field ΦS that reduces the magnetic field ΦM formed by the horizontal deflection coil, the center of deflection can be moved to the display screen near the upper and lower ends, and a margin for the neck shadow near the upper and lower ends is correspondingly increased. The degree can be increased. Thus, in this embodiment, neck shadows near the upper and lower ends can be effectively avoided, the deflection sensitivity can be increased accordingly, and the overall shape can be reduced in size.

In the above embodiment, the case where the sub-coils 9 are connected in series and then connected to the saturable reactor 10 has been described. However, the present invention is not limited to this, and two saturable reactors 10 are prepared. Alternatively, each saturable reactor 10 and sub-coil 9 may be connected in series and connected in parallel with the horizontal deflection coil. Alternatively, each secondary winding may be connected to the sub-coil 9 using a saturable reactor having a second secondary winding.

Further, in the above-described embodiment, the case where the horizontal deflection current flowing through the sub-coil 9 is modulated by the vertical deflection current using the saturable reactor 10 has been described. After flowing a part of
What is necessary is just to modulate it with the vertical deflection current and supply it to the sub coil,
Various modulation means can be widely applied.

In the above-described embodiment, the case where the sub-coil is formed by the self-bonding wire has been described. However, the present invention is not limited to this. Various coil forming methods can be widely applied, for example, when forming by direct winding.

Further, in the above embodiment, the case where both the horizontal deflection coil and the vertical deflection coil are formed in a saddle type by section winding has been described. However, the present invention is not limited to this, and the vertical deflection coil is toroidally wound. In some cases, the present invention can be widely applied to various types of deflection yokes.

[0042]

As described above, according to the present invention, a sub coil is arranged on the electron gun side of the horizontal deflection coil so as to correspond to the horizontal deflection coil, and a part of the horizontal deflection current is modulated by the vertical deflection current. Then, the magnetic field is supplied to the sub-coil to form a magnetic field for reducing the magnetic field formed by the horizontal deflection coil, whereby the deflection center can be moved to the display screen near the upper and lower ends. As a result, it is possible to increase the margin near the upper and lower ends of the neck shadow, thereby effectively avoiding the neck shadow, increasing the deflection sensitivity, and reducing the overall shape.

[Brief description of the drawings]

FIG. 1 shows a deflection yoke according to an embodiment of the present invention.
It is an approximate line figure used for explanation of movement of a deflection center.

FIG. 2 is a side view showing the overall configuration of the deflection yoke of FIG.

FIG. 3 is a perspective view showing a relationship between a horizontal deflection coil and a sub coil in the deflection yoke of FIG. 2;

FIG. 4 is a connection diagram showing connection of sub-coils in the deflection yoke of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deflection yoke 4 Core 7 Horizontal deflection coil 8 Vertical deflection coil 9 Subcoil 10 Saturable reactor

Claims (2)

(57) [Claims] 1. A deflection yoke held by a neck of a cathode ray tube and electromagnetically deflecting the cathode ray tube, the deflection yoke being opposed to each other with the neck of the cathode ray tube interposed therebetween and forming a horizontal deflection magnetic field. A horizontal deflection coil, a sub-coil arranged on the electron gun side of the horizontal deflection coil so as to correspond to the horizontal deflection coil, and a magnetic field of the sub-coil in a direction to cancel a magnetic field formed by the horizontal deflection coil. A deflection circuit for modulating a part of the horizontal deflection current with the vertical deflection current and supplying the modulated partial deflection current to the sub-coil. 2. The modulation circuit is formed of a saturable reactor having a primary winding and a secondary winding, supplies a vertical deflection current to the primary winding, and connects the secondary winding to the sub-coil. The deflection yoke according to claim 1, wherein the deflection yoke is connected in series and connected in parallel with the horizontal deflection coil.