JPH04245149A - Cathode ray tube device - Google Patents

Abstract

PURPOSE:To reduce leakage magnetic field leaked from a deflecting yoke. CONSTITUTION:A 1/4 ring shape ferrite core (magnetic permeability: 320, electrical resistivity: 10<7>OMEGAcm) having the thickness of 3mm is arranged behind the front transition part of a saddle type horizontally deflecting coil as a magnetic substance 310. This magnetic substance 310 crosses at right angles to symmetrical planes of a pair of upper and lower saddle type deflecting coils inside planes perpendicular to a tubular axis, and is situated within 90 degrees range sandwiching planes containing the tubular axis. Furthermore, the distance from the tubular axis to the center of the length of the magnetic substance in the radial direction and the distance from the tubular axis to the center of the coils forming the transition part are set approximately equal to each other.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube device in which leakage magnetic fields leaking to the outside of a deflection yoke are reduced.

0002

2. Description of the Related Art Recently, mainly in Northern Europe, there has been a movement to control leakage magnetic fields leaking from cathode ray tube devices, taking into consideration the effects that magnetic fields have on the human body. The main source of leakage magnetic fields from cathode ray tube devices is the deflection yoke. The deflection yoke consists of a horizontal deflection coil that generates a horizontal deflection magnetic field that horizontally deflects and scans the electron beam emitted from the electron gun of the cathode ray tube, and a vertical coil that generates a vertical deflection magnetic field that deflects and scans the electron beam vertically. It mainly consists of a deflection coil. It is necessary to reduce the magnetic flux of the portion of the magnetic field generated by the deflection yoke that does not contribute to the deflection of the electron beam, that is, the leakage magnetic flux, to a considerable level.

A deflection yoke 10 shown in FIG. 13 is a general deflection yoke mounted on a cathode ray tube such as a color picture tube. Inside the separator 11, a pair of upper and lower saddle-shaped deflection coils 12 that horizontally deflect an electron beam emitted from an electron gun of a cathode ray tube are arranged symmetrically with respect to the horizontal axis (X axis). A pair of left and right saddle-shaped deflection coils 13 that deflect the electron beam in the vertical direction are arranged symmetrically with respect to the vertical axis (Y-axis).

In this deflection yoke 10, most of the magnetic flux generated from the horizontal deflection coil 12 is confined within the internal space of the deflection yoke, but a portion is radiated to the outside of the deflection yoke as leakage magnetic flux. FIG. 14(a) shows the distribution of the leakage magnetic field near the saddle type horizontal deflection coil when viewed from the horizontal direction. The leakage magnetic flux BO of the saddle-type horizontal deflection coil 20 is in the same direction as the deflection main magnetic flux BI caused by the main coil portion 21 of the saddle-type horizontal deflection coil 20 before and after the deflection yoke. Further, the leakage magnetic flux near the transition portion 22 of the saddle type horizontal deflection coil 20 is expressed as BS. Figure 1
4(b) shows the leakage magnetic field near the saddle type horizontal deflection coil as seen from the tube axis direction. Although the above-mentioned deflection yoke has been described with a saddle-type vertical deflection coil, even with a toroidal-type vertical deflection coil, the leakage magnetic field is similar to that shown in FIG. 14.

[0005]Currently, the subject of regulation of leakage magnetic fields is limited to horizontal deflection magnetic fields, but it is necessary to reduce both horizontal and vertical leakage magnetic fields. The leakage state of the vertical deflection magnetic field due to the vertical deflection coil is also distributed in almost the same way, except that the direction of the magnetic flux is different by 90 degrees.

Countermeasures against this leakage magnetic field include a compensation coil system that generates a compensating magnetic field of the same magnitude in the opposite direction to the leakage magnetic field in order to cancel the horizontal deflection leakage magnetic field, and There is a shield method that covers it with a shield member.

However, with the compensation coil method, it takes time and effort to adjust the mounting position, angle, etc. of the coil. Furthermore, when a new compensating coil for the leakage magnetic field of the vertical deflection magnetic field is installed, there are problems of a space for installing the compensating coil and an increase in power consumption. For example, Japanese Patent Application Laid-Open No. 62-64024 discloses a saddle type deflection coil 30 as shown in FIG.
An auxiliary coil 32 having substantially the same shape as the horizontal deflection coil 30 is arranged outside the core 31 with the core 31 in between, and a magnetic flux shown by an arrow 34 in the opposite direction to the main magnetic flux of the horizontal deflection coil 33 passes through this. As shown in FIG. 1, a part of the current flowing through the horizontal deflection coil is made to flow in an opposite phase to reduce the leakage magnetic flux of the horizontal deflection coil. However, this method using an auxiliary coil requires an additional circuit, and it is difficult to control the leakage magnetic flux at a predetermined position to reduce it to a predetermined level. Further, regarding the shielding method, the display section on the front side of the cathode ray tube device cannot be shielded, and the effect against leakage magnetic fields on the front side of the cathode ray tube device is low.

Furthermore, as an inexpensive and compact means different from the above method, Japanese Patent Application Laid-Open No. 64-45046 discloses
A method is shown in which a magnetically permeable ring is arranged between the screen of the cathode ray tube and the deflection yoke as a magnetic shunt means to reduce the leakage magnetic field. The cathode ray tube device disclosed in this Japanese Patent Application Laid-Open No. 64-45046 is shown in FIG. Front transition portion 41 of saddle-type horizontal deflection coil 40 of deflection yoke
A linear ferrite ring 42 with relatively high magnetic permeability and high resistivity is installed adjacent to the ring. This linear ferrite ring 42 acts as a magnetic shunt means to reduce leakage magnetic fields.

However, in the structure shown in FIG. 16, since the ring is installed in front of the deflection yoke, there is a limit to the size of the ring. In addition, the work of actually attaching the deflection yoke to the cathode ray tube and adjusting its position (hereinafter referred to as ITC work)
In this case, a wedge is inserted between the cathode ray tube and the deflection yoke to fix it, so the above-mentioned structure does not allow the wedge to be inserted, making ITC work difficult. Furthermore, in order to minimize the leakage magnetic field, it is necessary to make the inner diameter of the ring as small as possible so that it approaches the neck diameter of the cathode ray tube. Even with such a shape, there are problems in ITC work. In addition, the distance between the front end of the deflection yoke and the cathode ray tube is usually about 3 mm or less, and in order to minimize the leakage magnetic field, the linear ferrite ring must be at least several mm thick. This requires changes to design values such as YPB (York Pull Back), which determines the deflection center position of the deflection yoke of the cathode ray tube device, which also impairs the display characteristics of the cathode ray tube device and requires major design changes to the cathode ray tube device. It arises.

0010

[Problems to be Solved by the Invention] As mentioned above, the method of using a compensation coil as a countermeasure against leakage magnetic field from a cathode ray tube device requires an additional circuit, increases deflection power,
Furthermore, there is a problem in that it is difficult to control the leakage magnetic flux at a predetermined position to reduce it to a predetermined level. In addition, a structure in which a magnetically permeable ring is placed between the front end of the deflection yoke and the screen of the cathode ray tube makes ITC work difficult, and furthermore, it greatly changes the display characteristics of the cathode ray tube device.
There is also the problem that it becomes necessary to change the design of the cathode ray tube device. SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a cathode ray tube device that reduces leakage magnetic fields by simpler means. [Structure of the invention]

[0011]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a cathode ray tube device equipped with a deflection yoke constituted by at least one pair of saddle-type deflection coils. The present invention is characterized in that it has a magnetic body that reduces the leakage magnetic field from the saddle-type deflection coil at a position substantially symmetrical with respect to the plane of symmetry of the coil and behind the transition portion.

Further, in a cathode ray tube device including a deflection yoke constituted by at least one pair of saddle-type deflection coils, the angle is substantially perpendicular to the plane of symmetry of the pair of saddle-type deflection coils and includes the tube axis. It is characterized by having a magnetic body symmetrically located near the transition portion to reduce the leakage magnetic field from the saddle type deflection coil.

Furthermore, there is a cathode ray tube that displays an image on a phosphor screen by scanning the electron beam emitted from the electron gun, and a cathode ray tube that is attached to the cathode ray tube and deflects the electron beam emitted from the electron gun in a horizontal direction. a deflection yoke having a pair of upper and lower saddle-type deflection coils that generate a magnetic field, and a pair of left and right saddle-type deflection coils and cores that generate a magnetic field that vertically deflects an electron beam emitted from the electron gun; It is approximately symmetrical to the plane of symmetry of the pair of horizontal or vertical deflection coils of the deflection yoke and is located behind the transition part, and for the pair of vertical or horizontal deflection coils, it is parallel to the plane of symmetry of the pair of saddle vertical deflection coils. It is characterized by having a magnetic body that reduces the leakage magnetic field from the saddle type deflection coil at a position that is substantially symmetrical with respect to a plane that is orthogonal to each other and includes the tube axis and is located near the transition portion.

[0014]

[Operation] According to the present invention, the magnetic body is placed at a position substantially symmetrical to the plane of symmetry of a pair of saddle-type deflection coils and behind the transition portion, or at a position orthogonal to the plane of symmetry of a pair of saddle-type deflection coils. Since it is arranged at a position near the transition part and approximately symmetrical with respect to the plane including the tube axis, the magnetic body is magnetized in a direction that compensates for the leakage magnetic field from the saddle type deflection coil, that is, in the same direction as the main deflection magnetic flux. The magnetized magnetic body then generates a compensation magnetic field that compensates for the leakage magnetic field.

[0015]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Example 1)

FIG. 1 shows a vertical sectional view of a cathode ray tube device according to a first embodiment of the present invention. The cathode ray tube 100 in this device has an envelope consisting of a substantially rectangular panel 110 and a funnel-shaped funnel 120 that are joined together. Phosphor screen 130 consisting of a color phosphor layer
A shadow mask 140 in which a large number of electron beam transmission holes are formed is mounted closely facing the phosphor screen 130. Also, funnel 120
An electron gun 160 that emits three electron beams is disposed within the neck 150 of the device. Furthermore funnel 120
A deflection yoke 200 that generates a magnetic field that deflects the electron beam emitted from the electron gun 160 in the horizontal (X) and vertical (Y) directions is mounted outside the boundary between the cone and the neck 150. The transition portion 2 of the saddle type horizontal deflection coil 210 of this deflection yoke 200 is
A magnetic body 310 is placed at 20 .

This deflection yoke 200 and magnetic body 310
Fig. 2 shows the arrangement state. The deflection yoke 200 is shown in FIG.
As shown in FIG. 2, a horizontal deflection magnetic field is arranged inside the separator 230 vertically symmetrically across the horizontal axis (X axis), with the horizontal plane (XZ plane) as the plane of symmetry, and a horizontal deflection magnetic field that deflects the three electron beams in the horizontal (X) direction. The generated saddle type horizontal deflection coil 210 and the separator 230 are arranged symmetrically across the vertical axis (Y axis), with the vertical plane (YZ plane) being the plane of symmetry, and 3
It includes a saddle-type vertical deflection coil 240 that generates a vertical deflection magnetic field that deflects the electron beam in the vertical (Y) direction. The pair of horizontal deflection coils 210 each have a transition section in front of the fluorescent screen side and at the rear of the opposite electron gun side, and further have a pair of vertical deflection coils 240.
Both have transition parts on the fluorescent screen side and on the opposite electron gun side, respectively. Furthermore, the vertical deflection coil 24
0, a conical cylindrical core 250 is placed on the outer circumference of the horizontal and vertical coils so as to avoid them and surround them.
is located. Furthermore, as the magnetic body 310, a 1/4 ring-shaped ferrite core with a thickness of 3 mm (magnetic permeability of 3
20, resistivity 107 Ωcm) are arranged at positions behind the front transition portion, approximately symmetrical with respect to the plane of symmetry of a pair of upper and lower 14-inch saddle-type horizontal deflection coils.

Here, the term "back" refers to the part located inside the deflection coil in the tube axis direction, that is, the front transition part on the fluorescent screen side is on the electron gun side, and the rear transition part on the electron gun side is on the fluorescent screen side. shall be said.

Furthermore, the position where the magnetic body 310 is arranged is as follows:
Basically, it is a position that is magnetized in the direction of the main deflection magnetic flux,
The transition area has a range of 180 degrees around the tube axis, but
Preferably, the angle is within a 90 degree range that is perpendicular to the plane of symmetry of the pair of upper and lower saddle-type deflection coils and that includes the tube axis. In addition, the magnetic material is basically located in a plane perpendicular to the tube axis, and the distance from the tube axis to the center of the radial length of the magnetic material and the winding that forms the transition section from the tube axis It is preferable that the distance to the center of the tube be the same in the tube axis direction.

FIG. 3 shows the compensation effect of the leakage magnetic field when the magnetic body 310 is arranged as shown in FIG. Figure 3(a)
As shown in , since the leakage magnetic flux BS generated from the transition parts 260a, 260b is in the same direction as the deflection main magnetic flux BI behind the transition parts 260a, 260b, the magnetic body 31
0 is magnetized in the same direction as the main deflection flux BI. The compensation magnetic flux BH generated from the magnetized magnetic body 310 is in the opposite direction to the leakage magnetic flux BO before and after the deflection yoke.
This cancels the leakage magnetic flux BO. FIG. 3(b) is a diagram showing the direction of magnetization of the magnetic material and the compensation magnetic flux generated by the magnetic material as viewed from the front transition portion side of the deflection yoke.

FIG. 4 shows the distribution of the leakage magnetic field on the deflection yoke axis and the magnetic field generated from the magnetized magnetic material. In FIG. 4, the sign indicates the main deflection magnetic flux direction as +. As is clear from FIG. 4, the leakage magnetic field shown by the solid line is compensated for by the compensation magnetic field generated by the magnetized magnetic material shown by the broken line before and after the deflection yoke. In fact, by adopting the configuration shown in FIG. 2 above, the leakage magnetic field is reduced from 41 nT to 23 nT, making it possible to obtain an effect of about half. Furthermore, since the magnetic material is simply placed, no additional circuit is required and no increase in deflection power is involved.

[0022] Also, the larger the length of the magnetic body in the radial direction, the greater the compensation effect, but if the length is too large, it will also be magnetized by leakage magnetic fields other than the direction of the main deflection flux, so the radius of the magnetic body The length in the direction is determined taking these into consideration.

Furthermore, as shown in FIG. 2, in this embodiment,
Although the magnetic body 310 is placed outside the separator 230 of the deflection yoke and behind the transition portion, it may also be placed inside the separator 230 between the transition portion of the saddle-type deflection coil and the separator. good.

In Example 1 above, the shape of the magnetic body is reduced to 1/4
Although the magnetic body is ring-shaped, the shape of the magnetic body is not limited to the first embodiment. In fact, in order to compensate for the leakage magnetic field, it is necessary to magnetize the magnetic body in the direction of the main deflection magnetic flux, and it is better to minimize magnetization in other directions than this direction. This means that
As is clear from FIG. 3, the magnetization directions inside the 1/4 ring-shaped magnetic body are M1, M2, and M3, and have an inclination with the direction of the deflection main magnetic flux BI at both ends of the magnetic body. Since the compensation magnetic flux due to the magnetizations M2 and M3 is bent, the effect of compensating for the leakage magnetic field is small. Therefore, by reducing the range of the transition portion covered by the magnetic material, the magnetization M2, M3
The compensation effect will become larger if the magnetic material is made smaller and the magnetic material is made larger in the direction of magnetization M1. FIG. 5 shows a modification of the first embodiment in which the magnetic body 320 is shaped like a rectangular parallelepiped in order to increase the magnetization in the direction of the main deflection magnetic flux as much as possible and make the magnetization effect of the magnetic body efficient. In addition to this, various shapes are possible so as to adjust the distribution of the magnetic field generated from the magnetic material. Further, in the first embodiment described above, the magnetic body is placed behind the front transition part, but as shown in FIG. 6, it may be placed behind the rear transition part of the saddle type horizontal deflection coil.

Further, when the vertical deflection coil is a saddle type, the vertical deflection leakage magnetic field can be reduced by placing it behind the transition part of the saddle type vertical deflection coil. Furthermore, it is also possible to arrange magnetic bodies behind the front transition parts of both the saddle-type horizontal deflection coil and the saddle-type vertical deflection coil to reduce leakage magnetic fields in both the horizontal and vertical directions. . Furthermore, as shown in FIG. 7, it is also possible to integrate the magnetic body 340 with the core of the deflection yoke. (Example 2)

The first embodiment described above has a magnetic material behind the transition portion of the saddle type deflection coil. Next, a second embodiment of the present invention will be described. Since the overall configuration of the cathode ray tube device is the same as that of the first embodiment, detailed explanation will be omitted and the main parts will be explained.

FIG. 8(a) shows a second embodiment of the present invention, in which a 1/4 ring-shaped ferrite core (
A magnetic material 350 having a magnetic permeability of 320 and a resistivity of 107 Ωcm is placed in the vicinity of the front transition portion 260a of the 14-inch saddle-shaped horizontal deflection coil in a plane that is perpendicular to the plane of symmetry of the pair of saddle-shaped deflection coils and includes the tube axis. They are placed in approximately symmetrical positions.

A more specific explanation will be as follows. Generally, a saddle-type deflection coil includes a substantially linear main coil portion 270 that generates a main deflection magnetic flux, and a main coil portion 270 that generates a main deflection magnetic flux.
70, and a transition section continuously formed before and after the bridge. The position where the magnetic body 350 is placed is basically a position where it is magnetized in the direction of the main deflection magnetic flux. To schematically show this, the cross section of the main coil portion of a saddle type horizontal deflection coil is viewed from the front in the tube axis direction. The result will be as shown in FIG. 8(b). If the angle between the X-axis and the main coil portion is θ, the magnetic body is arranged in a range of 2θ formed symmetrically with respect to the Y-axis near the transition portion. In this embodiment, the coils are arranged in a range of 90 degrees between the plane of symmetry (XZ plane) of the pair of upper and lower saddle type horizontal deflection coils 210 with the tube axis as the center. Note that the cross-sectional shape of the main coil portion shown in FIG. 8(b) differs depending on the shape of the deflection coil, and as a result, it goes without saying that it is necessary to appropriately determine the position where the magnetic body is disposed.

FIG. 9 shows the compensation effect of the leakage magnetic field when the magnetic body 350 is arranged as shown in FIG. 8(a). Figure 9
As shown in (a), the leakage magnetic flux BO of the saddle type deflection coil 210 is in the same direction as the main deflection magnetic flux BI before and after the deflection yoke. Furthermore, the leakage magnetic flux BS generated from the transition portions 260a, 260b of the saddle type horizontal deflection coil 210 is generated so as to surround the transition portions 260a, 260b. From the main coil section 270 to the transition section 26
There is a strong leakage magnetic flux BO in the same direction as the main deflection magnetic flux BI in the vicinity of the transition to 0a and 260b. Due to this leakage magnetic flux BO, the magnetic body 350 is magnetized in the direction of the main deflection magnetic flux BI, and the compensation magnetic flux BH generated by the magnetic body 350 is in the opposite direction to the leakage magnetic flux BO before and after the deflection yoke 200, thereby canceling the leakage magnetic flux BO. Ru. FIG. 9(b) is a diagram of the magnetization of the magnetic body 350 and the compensation magnetic flux BH generated by the magnetic body 350 as viewed from the front transition portion side of the deflection yoke.

FIG. 10 shows the distribution of the leakage magnetic field on the deflection yoke axis and the magnetic field generated from the magnetized magnetic material. In FIG. 10, the sign indicates the deflection main magnetic flux direction as +. From this figure, it can be seen that the leakage magnetic field shown by the solid line before and after the deflection yoke is compensated by the compensation magnetic field of the magnetic body shown by the broken line. In fact, by adopting the above configuration, the leakage magnetic field can be reduced from 41 nT to 14 nT.

Further, in the embodiment shown in FIG. 8, the saddle type deflection coils are arranged in the vicinity of the front transition portion of the saddle type deflection coils at positions that are perpendicular to the plane of symmetry of the pair of saddle type deflection coils and symmetrical to a plane that includes the tube axis. The pair of magnetic bodies 350 is shaped like a 1/4 ring with both ends protruding outward in the radial direction. This is because if the magnetic body is ring-shaped and bent, the compensation magnetic flux generated will also be bent, so by protruding outward and making the tip an acute angle, it is easier to generate compensation magnetic flux. , the length of the magnetic body is substantially increased in the magnetization direction to increase the compensation effect.

In the above Example 2, the shape of the magnetic body is reduced to 1/4.
Although the magnetic body is ring-shaped, the shape of the magnetic body is not limited to that of the second embodiment. In fact, in order to compensate for the leakage magnetic field, it is necessary to magnetize the magnetic body in the direction of the main magnetic flux, and it is better to have as little magnetization as possible in other directions. FIG. 11 shows a modification of the second embodiment in which a rectangular parallelepiped-shaped magnetic body 360 is arranged in order to increase the magnetization in the main magnetic flux direction as much as possible and make the magnetization effect of the magnetic body efficient. In addition to this, various shapes are possible so as to adjust the distribution of the magnetic field generated from the magnetic material. Further, in the above embodiment, the magnetic material is placed in front of the connection between the front transition section and the main coil section, but it may be placed near the connection section between the rear transition section and the main coil section. (Example 3)

In the first and second embodiments described above, the position of the pair of saddle type horizontal or vertical deflection coils is approximately symmetrical with respect to the plane of symmetry and is behind the transition part, or the position of the pair of vertical or horizontal deflection coils is approximately symmetrical with respect to the plane of symmetry. In this case, a magnetic material is arranged at a position near the transition part, which is perpendicular to the plane of symmetry of the pair of saddle vertical deflection coils and approximately symmetrical to a plane containing the tube axis, and constitutes a deflection yoke. The shape of the other pair of deflection coils may be saddle type or toroidal type. However, when the horizontal deflection coil and the vertical deflection coil of the deflection yoke are both saddle-shaped, the leakage magnetic field can be compensated for simply by placing a magnetic body between the two pairs of saddle-shaped deflection coils. For example, Figure 12
As shown, a pair of saddle-shaped horizontal deflection coils 210
is approximately symmetrical with respect to the plane of symmetry and is behind the transition part, and
As for the pair of saddle-type vertical deflection coils 240, a 1/4-inch coil is placed at a position near the transition portion, which is approximately symmetrical to a plane that is perpendicular to the plane of symmetry of the pair of saddle-type vertical deflection coils and includes the tube axis.
A magnetic body 370 made of a ferrite ring is arranged. By arranging the magnetic body 370 in this way, the leakage magnetic field from the saddle type horizontal deflection coil 210 and the leakage magnetic field from the saddle type vertical deflection coil 240 can be reduced.
As described above, the magnetic bodies are magnetized in directions that compensate for their respective leakage magnetic fields, and generate compensation magnetic fields. The magnetization effect of this magnetic material is as explained in Example 1 and Example 2 above.

In any of the above embodiments 1 to 3, if there is an imbalance in the compensation magnetic field before and after the deflection yoke, the principle of the present invention can be used in reverse to eliminate the imbalance. be able to. That is, when a magnetic body is disposed behind the front transition portion of the saddle-type horizontal deflection coil to compensate for the leakage magnetic field in the front, overcompensation may occur at the rear of the deflection yoke, and the compensation magnetic field may remain. In such a case, the leakage magnetic field may be increased in the portion where the compensation magnetic field remains. That is, the magnetic material may be placed on the electron gun side of the rear transition portion of the saddle type horizontal deflection coil. If the magnetic material is arranged in this way, the magnetic material will be magnetized in the opposite direction to the main deflection magnetic flux due to the leakage magnetic field from the transition section, and a magnetic flux in the same direction as the leakage magnetic flux will be generated, thereby eliminating the imbalance caused by the above-mentioned overcompensation. be able to.

Further, in the first to third embodiments described above, a ferrite core is used as the magnetic material, but the magnetic material is not limited to the above. For example, it is also possible to use a magnetic alloy such as permalloy. When permalloy is used, the thickness of the magnetic material can be made thinner, so the influence on the display characteristics of the cathode ray tube device can be reduced compared to a ferrite core.

[0036]

As described above, according to the present invention, a position that is substantially symmetrical with respect to a plane of symmetry of a pair of saddle-type deflection coils and behind a transition portion, or a position that is symmetrical of a pair of saddle-type deflection coils By arranging the magnetic material in a position that is perpendicular to the plane and near the transition section and approximately symmetrical to the plane that includes the tube axis, the magnetic material is magnetized in a direction that compensates for the leakage magnetic field from the saddle-type deflection coil. Generates a magnetic field.

[0037] Therefore, since the magnetic material is simply arranged, the leakage magnetic field can be compensated for without adding an additional circuit, and since the structure does not cover the entire front side of the deflection yoke,
The influence on ITC work and the design of cathode ray tube devices can be suppressed, and leakage magnetic fields can be reduced by simpler means.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a first embodiment of a cathode ray tube device according to the present invention.

FIG. 2 is a perspective view showing the arrangement of a deflection yoke and a magnetic body in FIG. 1;

FIG. 3 is a schematic diagram illustrating the effect of the magnetic material according to the present invention.

FIG. 4 is a schematic diagram illustrating magnetic field distribution according to the present invention.

FIG. 5 is a perspective view showing a modification of the first embodiment shown in FIG. 2;

FIG. 6 is a perspective view showing another modification of the first embodiment shown in FIG. 2;

7 is a perspective view showing another modification of the first embodiment shown in FIG. 2. FIG.

FIG. 8 is a diagram showing a second embodiment of the present invention.

9 is a schematic diagram illustrating the effect of the magnetic material in FIG. 8. FIG.

10 is a schematic diagram illustrating the magnetic field distribution in FIG. 8. FIG.

11 is a perspective view showing a modification of the second embodiment shown in FIG. 8. FIG.

FIG. 12 is a perspective view showing a third embodiment of the present invention.

FIG. 13 is a perspective view showing a deflection yoke of the cathode ray tube device.

14 is a schematic diagram illustrating a leakage magnetic field of the deflection yoke in FIG. 13. FIG.

FIG. 15 is a plan view showing a compensation coil system for compensating for the leakage magnetic field of a deflection yoke in the prior art.

FIG. 16 is a diagram illustrating an arrangement of magnetically permeable rings that compensate for leakage magnetic fields of a deflection yoke in the prior art.

[Explanation of symbols]

200...Deflection yoke 210...Saddle type horizontal deflection coil 240...Saddle type vertical deflection coil 220, 260a, 260b...Transition part 270...Main coil part 310, 320, 330, 340, 350, 360, 3
70 ... Magnetic body BI ... Deflection main magnetic flux BS ... Leakage magnetic flux generated from the transition section BO ... Leakage magnetic flux BH ... Compensation magnetic flux

Claims (3)

[Claims] 1. In a cathode ray tube device comprising a deflection yoke constituted by at least one pair of saddle-shaped deflection coils, the deflection yoke is substantially symmetrical with respect to a plane of symmetry of the pair of saddle-shaped deflection coils and is located behind a transition portion. A cathode ray tube device characterized in that it has a magnetic material at a position that reduces leakage magnetic field from the saddle type deflection coil. 2. A cathode ray tube device comprising a deflection yoke constituted by at least one pair of saddle-shaped deflection coils, wherein the deflection yoke is approximately perpendicular to a plane of symmetry of the pair of saddle-shaped deflection coils and includes the tube axis. A cathode ray tube device characterized by having a magnetic body symmetrically located near a transition portion to reduce a leakage magnetic field from the saddle type deflection coil. 3. A cathode ray tube that displays an image on a phosphor screen by scanning an electron beam emitted from an electron gun, and a cathode ray tube that is attached to the cathode ray tube and deflects the electron beam emitted from the electron gun in a horizontal direction. a pair of upper and lower saddle-type deflection coils that generate a magnetic field, and a deflection yoke that has a pair of left and right saddle-type deflection coils and cores that generate a magnetic field that vertically deflects the electron beam emitted from the electron gun; It is substantially symmetrical to the plane of symmetry of the pair of horizontal or vertical deflection coils of the deflection yoke, and is located behind the transition part, and for the pair of vertical or horizontal deflection coils, the plane of symmetry of the pair of saddle vertical deflection coils. A cathode ray tube device comprising: a magnetic body that reduces leakage magnetic field from the saddle-type deflection coil at a position substantially symmetrical with respect to a plane that is orthogonal to the plane and includes the tube axis and is located near the transition portion.