KR910001402B1 - Daflection yoke - Google Patents

Abstract

A deflection yoke consisting of a tubular core and first and second deflection coils, in which a first deflection coil is wound on the tubular core and reduced on the longitudinal axis of the tubular core to reduce distortion on the curved screen of the SP panel of the cathode ray tube. The electron beams, which are arranged symmetrically with respect to each other, are deflected horizontally toward the fluorescent screen portion, and the second deflection coil is wound annularly on the tubular core to deflect the electron beams in the vertical direction.

Description

Deflection yoke

1 is a perspective view of a deflection yoke according to an embodiment of the present invention.

2 and 3 are schematic sectional views seen from the front of the deflection yoke of FIG. 1 used to explain the operation of the embodiment.

4 and 5 are schematic diagrams illustrating a raster of a cathode ray providing a deflection yoke according to the present invention and illustrating a method for correcting distortion.

6 to 9 are schematic diagrams showing another modification of the magnetization means used for the deflection yoke.

10 is a perspective view of the deflection yoke according to the second embodiment of the present invention.

FIG. 11 is a schematic sectional view seen from the front of the deflection yoke of FIG. 10 used to explain the operation of the second embodiment;

12 is a perspective view of a modification of the deflection yoke shown in FIG.

13 is a perspective view of a deflection yoke according to an embodiment of the present invention.

FIG. 14 is a schematic sectional view seen from the front of the deflection yoke of FIG. 13 used to explain the operation of the third embodiment; FIG.

FIG. 15 is a perspective view of a modified form of the deflection yoke shown in FIG.

16 is a cross-sectional view from the front of the deflection yoke according to the fourth embodiment of the present invention.

FIG. 17 is a sectional front view of the deflection yoke of FIG. 16 illustrating the relationship between the direction of current and the deflection direction of the electron beam; FIG.

FIG. 18 is an enlarged view of a portion of FIG. 17. FIG.

19 is a schematic vertical sectional view of a color cathode ray tube using a conventional deflection yoke.

20 is a perspective view of a conventional deflection yoke.

FIG. 21 shows the fluorescent screen portion of the cathode ray tube of FIG. 19 in a Cartesian coordinate system.

Fig. 22 is a diagram showing the positional relationship between a fluorescent screen portion and a deflection yoke in a color cathode ray tube.

23 is a schematic partial cross-sectional view showing the shape of a fluorescent screen portion of an SP panel or an aspherical surface in a color cathode ray tube;

24 is a diagram showing distortion occurring in a screen of a column cathode ray tube having a spherical surface.

FIG. 25 is a diagram similar to FIG. 24, showing distortion occurring in the screen of a color cathode ray tube provided with an SP panel.

FIG. 26 is a diagram showing sigal distortion occurring on a screen after being corrected by a conventional distortion correction circuit. FIG.

27 is a perspective view of a conventional deflection yoke designed to minimize the occurrence of sigal distortion.

FIG. 28 is a schematic cross-sectional view of the conventional deflection yoke of FIG. 27 used for explaining operation;

FIG. 29 is a diagram showing distortion occurring on a screen of a color cathode ray tube provided with the deflection yoke of FIG. 27; FIG.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to deflection yokes in cathode ray beams used in television receivers, and particularly to color cathode ray tubes in the vicinity of funnel and neck portions to deflect electron beams emitted from electron guns in cathode ray tubes. It relates to a deflection yoke to be mounted.

The conventional deflection yoke of the present invention will be described with reference to the accompanying drawings.

First, in FIG. 19, which is a schematic vertical cross-sectional view of a color cathode ray tube using a conventional deflection yoke, the color cathode ray tube 50 has a cylindrical shape protruding from a short diameter end of the conical funnel portion 52 and the funnel portion 52. It includes a high vacuum envelope consisting of a screen portion 51 of the neck portion 53, the opposite side of the neck portion 53 is provided on the long diameter end of the funnel portion 52. The screen 51 arranges the fluorescent film 55 on the inner surface of the effective screen portion 100 of the screen 51, and the portion of the screen 51 on which the fluorescent film 55 is disposed is separated from the neck portion 53. It is concave to protrude in the outward direction away. The cathode ray tube is a shadow mask 56 of a small hole located in the interior of the screen 51 at a predetermined interval so as to be parallel to the electron gun 54 provided in the neck portion 53 and the screen 51. It includes. As is well known in the art, the shadow mask 56 is generally composed of a thin metal plate having a constant pattern of three small holes 56a in which a precise circular hole is formed and bent in accordance with the curvature of the screen 51. have. The shadow mask 56 has an outer circumference portion fixed to the support frame 57 which is maintained at the same interval with respect to the screen 51 inside the screen 51 by means of a retainer (not shown).

The deflection yoke 1 is mounted on the outside of the cathode ray tube 50 at the boundary between the funnel portion 52 and the neck portion 53.

In the cathode ray tube 50 having the above-described configuration, the electron beam 70 emitted from the electron gun 54 travels toward the screen 51 through the hole 56a of the shadow mask 56 and the effective screen portion 100 is provided. That is, it hits the fluorescent screen. The electron ratio 70 emitted from the electron gun 54 toward the fluorescent screen unit 100 passes through the electromagnetic field generated inside the cathode ray tube 50 by the deflection yoke 1. The electron beam 70 is deflected at the center of deflection D of the effective field while the electron beam 70 passes through the electric field, and after passing through the small hole 56a of the shadow mask 56, the constant of the fluorescent film 55 It hits a part and emits light in that part.

A conventional deflection yoke 1 is described with reference to FIG. 20, which is a perspective view showing the neck from the neck portion 53 to the funnel portion 52 from the back. As shown, the deflection yoke 1 generally comprises a tubular core 2 made of a ferromagnetic material such as ferrite, a horizontal deflection coil 3 and a vertical deflection coil 4, for example. The horizontal deflection coil 3 consists of a pair of saddle-shaped coils wound around the tubular core 2 and arranged symmetrically with respect to the longitudinal axis of the tubular core 2, and an electromagnetic field necessary for deflecting the electron beam 70 in the horizontal direction. Used to generate Similarly, the vertical deflection coil 4 also consists of a pair of coils wound around the tubular core 2 in an annular shape and arranged symmetrically with respect to the longitudinal axis of the tubular core 2, and the electromagnetic field required to deflect the electron beam 70 in the vertical direction. Used to generate

In the cathode ray tube of the above-described configuration, there is a problem in that a part of the shadow mask 56 is bent or a dome phenomenon occurs. This dome phenomenon is a phenomenon in which the shadow mask 56 is locally raised as a result of the collision of the electron beam 70 and convex in the traveling direction of the electron beam 70, and then the electron beam 70 is the fluorescent screen part 100. Drive towards As a result, thermal expansion occurring in the localized portion of the shadow mask 56 where the heat is concentrated causes the localized portion of the shadow mask 56 to be outward with respect to the traveling direction of the electron beam 70, that is, the fluorescent screen portion 100. Further protrude in the adjacent direction. Once this dome occurs, the local portion of the shadow mask 56 is changed from its original position to another position where the shadow mask 56 does not preferably shield the electron beam 70, and the fluorescent screen portion 100 ), The electron beam 70 passes poorly, resulting in a decrease in color purity.

As one of the measures for reducing the dome phenomenon, "Television, Vol. 31, No. 6, p46-52" describes that the radius of curvature of the shadow mask should be as small as possible.

Since the curvature of the shadow mask 56 is generally selected in consideration of the curvature of the fluorescent screen portion 100 of the screen 51, an effective means for reducing the radius of curvature of the shadow mask 56 is to screen (51). It is to select the smallest possible radius of curvature of the fluorescent screen portion 100 on the image.

However, the choice of a smaller radius of curvature of the fluorescent screen portion 100 results in a generally convex shadow mask 56 and a cathode ray in which the fluorescent screen portion 100 further protrudes in the direction toward the television viewer. The tube was proposed. The proposal of such a cathode ray tube is markedly different from the recent trend of designing a flat screen to provide a good image.

In light of recent trends, it has been compromised to provide cathode ray tubes with screens in the form of aspherical surfaces, and the aspherical surfaces are described next as SP panels.

Here, the problem of the characteristics of the SP panel and the unique image distortion of the cathode ray tube having the SP panel will be described.

In FIG. 21 showing the rectangular optical screen unit 100 in a Cartesian coordinate system, the zero point is positioned at the center of the fluorescent screen unit 100 in a straight line with the vertical axis of the cathode ray tube 50, and the x axis is a fluorescent screen unit ( A direction parallel to the rectangular long surface of 100), the y axis is a direction parallel to the rectangular short surface of the fluorescent screen unit 100, and a z axis is a direction in which the fluorescent screen unit 100 protrudes. The x and y axes correspond to the horizontal and vertical deflection directions of the deflection yoke 1 shown in FIG.

FIG. 22 shows the positional relationship between the deflection yoke 1 and the fluorescent screen portion 100, and FIG. 23 is a schematic sectional view showing the half portion of the fluorescent screen portion 100 given in the xy plane. If the cut surface of the fluorescent screen unit 100 is z = f (x), the radius of curvature px is expressed by the following equation when X is an arbitrary value.

P _X =-(1+ (df / dx) ² ) ^3/2 / (d ² f / dx ² )

Therefore, when the radius of curvature Px is a positive value, the fluorescent screen unit 100 protrudes in the + z axis direction.

If the distance from the origin 0 to one end of the fluorescent screen portion 100 in the x-axis direction is Xmax, the SP panel may have a portion having a radius of curvature smaller than the radius of curvature Po at x = O, and the portion is the origin on the xy plane. It can be said that it is located between 2 / 3Xmax and 3 / 4Xmax, each of which is far from zero.

In the cathode ray tube having the above-described SP panel, the reason why the occurrence of the dome phenomenon can be reduced well without adversely affecting the flatness of the screen will be described next.

In particular, even if the dome phenomenon occurs severely near the center of the shadow mask 56 having a small deflection angle, that is, near the center (x = O) of the fluorescent screen part 100, the local displacement of the shadow mask 56 remains uneven. Since the misalignment is small at the position of the collision point of the electron beam 70, the realistic damage is small, and the flatness near the center of the fluorescent screen part 100 is important to make the SP panel look flat, so that the radius of curvature Po is relatively large. It is desirable to.

Since the periphery of the shadow mask 56 is fixed by the support frame 57 in the periphery of the fluorescent screen part 100 away from the center Xmax, the periphery of the shadow mask 56 is substantially deformed due to the dome phenomenon. Disappears directly. Also, even if there is a variation, the television viewer's gaze is not concentrated on the periphery of the SP panel, so the television viewer is not adversely affected. In light of this, the radius of curvature P at x = Xmax is not very important.

Taken together, the portion of the fluorescent screen portion 100 between x = O and x = Xmax, in particular between x = 2 / 3Xmax and x = 3 / 4Xmax, in order to reduce the occurrence of dome phenomenon and incidental deformation of color purity. It can be concluded that the radius of curvature Px at should be as small as possible compared to the surface curvature Po at the center of the fluorescent screen portion 100. The SP panel was developed based on this conclusion.

Another problem relating to image distortion to be reproduced is described next. For example, FIG. 24 shows the result of reproducing and deflating horizontally parallel image lines on a screen of a cathode ray tube having a spherical fluorescent screen portion 100. FIG. In particular, the horizontal image line 110 should be played side by side like a dotted line in FIG. 24, but the horizontal image line 110 actually reproduced is bent so that the distance in the x-axis direction is farther away from the center of the fluorescent screen portion on the x axis. Away. This is because the distance between the deflection point D in the electromagnetic field generated by the deflection yoke 1 and the fluorescent screen shown in FIG. 19 increases as the distance from the center of the fluorescent screen portion 100 in the x-axis direction. . Assuming that the displacement amount of the horizontal image line 110 farther from the x-axis is Δy as it moves away from the center of the fluorescent screen unit 100 in the x-axis direction, the coordinate point of the fluorescent screen unit 100 in the Cartesian coordinate system is When (x, y), the displacement amount Δy is substantially proportional to x ² y. In general, since the shape of the fluorescent screen unit 100 is spherical, when the radius of curvature of the fluorescent screen unit 100 is reduced, the displacement amount Δy may be reduced to some extent. In addition, if the shape of the electromagnetic field generated by the deflection yoke 1 is properly adjusted, the displacement amount? Y can be reduced to some extent.

Even if the radius of curvature of the fluorescent screen unit 100 is reduced and the shape of the electromagnetic field is adjusted, it is difficult to completely remove the distortion of the horizontal image line 110 and a slight displacement amount Δy remains. And since the amount of displacement Δy remaining is still proportional to a simple function value of x ² y or the 2nd order of x and the 1st order of y, the distortion compensation circuit added to the deflection circuit can substantially reduce the distortion.

The same horizontal image line 110 is reproduced on the screen in the cathode ray tube having the SP panel with reference to FIG. 25, which is a schematic illustration. In the SP panel, since the radius of curvature of the fluorescent screen portion 100 in the xz plane is as described above, the amount of change in the gap between the deflection point D and the fluorescent screen portion 100 is x = 2 / in the xy plane. The position of 3Xmax is different from inside to outside, and therefore, not only is the displacement Δy proportional to the value of x ² y, but also the horizontal image line 110 away from the x axis is the center of the fluorescent screen unit 100 (x> 2 / 3Xmax). There is a tendency to approach the x-axis suddenly outside of 2 / 3Xmax away from it.

As a means of thinking of the entire screen as a plane, the horizontal image line 110 in the x-axis when viewed in a cross section of one long side portion (eg, y = Ymax position) of a given SP panel along a plane parallel to the xz plane. It is also possible to predict that the amount of change of the fluorescent screen portion 100 in the z-axis direction is reduced as a result of reducing this warpage. When using this method, the horizontal video line 110 reproduced on the screen is as shown in FIG.

Distortion shown in FIG. 26 represents seagal distortion. The use of the distortion compensation circuit in the deflection circuit is effective to substantially reduce the occurrence of sigal distortion. However, it is difficult to devise a distortion compensation circuit, and even if it is possible, the displacement amount? Y becomes a higher order function of x and y, resulting in an increase in the manufacturing cost of the cathode ray tube.

FIG. 27 is a schematic perspective view of a conventional deflection yoke 1 designed to substantially reduce the occurrence of sigal distortion shown in FIG. As shown in FIG. 27, the deflection yoke 1 shown in FIG. 19 and FIG. 20 also has an end face flanger fitted to the large diameter end of the core 2, spaced 180 degrees apart from each other on the longitudinal axis of the core 2; A pair of bipolar magnets 10, which are fixed to 8a and aligned at the exit of the electron gun which the electron beam is emitted outward toward the fluorescent screen portion, are provided. The deflection yoke 1 of FIG. 27 has a separator 8 mounted on the core 2 on the opposite side of the end face flange 8b.

The operation of the cathode ray tube of the configuration shown in FIG. 27 will be described with reference to FIG. By appropriately selecting the size and shape of each of the bipolar magnets 10, the inside of the deflection yoke 1 by the bipolar magnet 10 radiated from one pole of the other bipolar magnet 10 to the other pole The horizontal component of the magnetic flux 11 generated at is represented by a loop according to the three electron beams 70a, 70b, 70c, and 70d moving in four diagonal portions, as indicated by the arrow 11y. Similarly, three parts of the electron beams 70a to 70d that are coincident in the y-axis direction and away from the x-axis direction appear at any one of four corners of the screen spaced from the center of the screen in the diagonal direction. The sigal distortion can be reduced.

On the contrary, when considering the vertical component of the magnetic flux 11 generated inside the deflection yoke 1 by the bipolar magnet 10, three pairs of electron beams 70e and 70f, which are mainly deflected in the horizontal direction, are x Affected by the axial force 11x, the three electron beams 70e and 70f are pulled close to each other, that is, toward the screen center, and as a result, three electron beams 70e are pulled. , 70f is distorted as shown in 112 in FIG. 29, in which the pole protrusion 112a is inward of the screen center, and the needle flower exhibits distortion. Such needle flower distortion tends to increase in quadratic function as the electron beam traveling toward the fluorescent screen portion approaches the bipolar magnet 10, thus using a conventional needle flower compensation circuit that compensates for image distortion on the opposite side of the screen. The barrel distortion may occur near the screen center. In addition, the use of the conventional needle flower compensation circuit has a side problem that it is not effective to remove the distortion as shown by the local protrusion 112a of FIG.

Since the conventional deflection yoke designed to substantially eliminate the sigal distortion occurring in the cathode ray tube having the SP panel is configured as described above, the sigal distortion, which is a distortion generated in the vertical direction, is substantially reduced, while a distortion occurring in the horizontal direction. The distortion of the needle flower tends to be increased. In addition, the needle flower distortion generated is complicated and not uniform in the shape of the needle flower being reproduced with a local recess somewhere in the image state.

Accordingly, it is an object of the present invention, which is designed to substantially eliminate the above-mentioned problems and disadvantages of the prior art, and provides an improved deflection yoke of the above-described type to prevent distortions appearing on the curved screen of the SP panel of the cathode ray tube. It is to provide a deflection yoke that can be reduced by simple means, for example by winding the deflection coil appropriately.

The deflection yoke shown here for achieving the above object of the present invention is a tubular core, wound around the core and arranged symmetrically to each other on the longitudinal axis of the core, and to horizontally deflect the electron beam emitted from the electron gun toward the fluorescent screen portion. A first deflection coil of the pair, a second deflection coil wound annularly on the core to deflect the electron beam in a vertical direction. The pair of magnet members are mounted on the core facing each other and are positioned on the image horizontal axis perpendicular to the vertical axis of the core with a 180 degree interval from each other on the vertical axis of the core. Each magnet member mounted to the core is composed of an elongated body having a pair of legs protruding from the elongated bodies with the legs spaced from each other in the vertical direction. In addition, the magnetizing means of each magnet member is provided to generate a predetermined pole on the leg of each magnet member, and the magnetic deflection force is applied to deflect the electron beam traveling toward one of the four corner regions of the fluorescent screen portion in a direction away from the horizontal axis. It can generate and minimize the magnetic deflection force in the horizontal direction in the vicinity of the horizontal axis.

According to the present invention, the magnetic flux is generated in the upper and lower sides with respect to the horizontal axis of the tubular core, so that the upward biasing force and the downward biasing force are directed to the upper and lower portions of the electron beam traveling on the upper portion and the lower portion below the horizontal axis. Occurs on the upper and lower diagonals to deflect.

In addition, although each magnet member is made of E-shape or U-shape, for example, no substantial force is generated which deflects a part of the electron beam traveling near the horizontal axis in the direction facing each other in the horizontal direction.

As described above, the present invention has the effect of reducing the segal distortion occurring in the vertical direction without distortion of the needle flower accompanying the horizontal direction.

In addition, according to the present invention, the second deflection coil wound around the tubular core has a main winding located within an angle not greater than about 70 degrees with respect to the vertical direction and an auxiliary winding located within an angle between about 65 degrees and about 90 degrees with respect to the vertical direction. It consists of.

The use of the second deflection coil of the above-described configuration is effective in reducing the occurrence of sigal distortion. In particular, when current flows through the main winding of the second deflection coil located within an angle no greater than about 70 degrees relative to the vertical direction, the composite magnetic flux acts on the part of the electron beam to deflect the latter in the vertical direction, while the vertical direction When current flows through the auxiliary winding of the second deflection coil located within an angle of about 65 degrees to about 90 degrees with respect to the composite magnetic flux acting on the part of the electron beam to deflect the latter in the diagonal direction of the screen of the cathode ray tube. The force acting on deflecting a part of the electron beam in the diagonal direction becomes stronger as the distance away from the center of the screen in the horizontal direction increases, i.e., as the electron beam approaches the auxiliary winding of the second deflection coil, the sigal distortion is substantially Can be effectively reduced.

Before explaining the present invention, it is noted that the same numbers in the reference figures indicate the same parts.

In FIG. 1, the deflection yoke 1 according to the embodiment of the present invention comprises a general-purpose tubular core 2, a horizontal deflection coil 3, and a vertical deflection coil 4 made of a ferromagnetic material such as ferrite. It is composed. The horizontal deflection coil 3 is composed of a pair of saddle coils wound on the tubular core 2 and arranged opposite to each other with respect to the longitudinal axis of the tubular core 2, and generate an electromagnetic field necessary for deflecting the electron beam in the horizontal direction. . Similarly, the vertical deflection coil 4 is also composed of a pair of coils wound annularly on the tubular core 2 and arranged opposite to each other with respect to the longitudinal axis of the tubular core 2, and generates an electromagnetic field necessary for deflecting the electron beam in the vertical direction. Occurs.

Further, the deflection yoke 1 shown in FIG. 1 includes a separator 8 for supporting the horizontal deflection coil 3 and the vertical deflection coil 4, and the separator 8 includes a funnel of a color cathode ray tube. It consists of a front end flange 8a adjacent to the channel portion and a rear end flange 8b adjacent to the neck portion of the cathode ray tube.

The deflection yoke 1 according to the invention comprises a magnet member 12 provided on both sides of the tubular core 2 and positioned on the transverse axis of the tubular core 1. The magnet members 12 located on both sides of the tubular core 2 are held symmetrically with respect to the longitudinal axis of the tubular core 2. As shown in FIG. 2, each of the magnet members 12 has a pair of legs 12b and legs 12b which protrude from their opposite ends in a direction perpendicular to the elongated body 12c at intervals from each other in the vertical direction. It is composed of an elongated body 12c having a middle leg 12a which is located in the middle between the protrusions and protrudes in the same direction as the legs 12b, and each magnet member 12 is composed of an E shape as a whole.

The magnet member 12 is mounted on the tubular core 2 with the legs 12a, 12b facing the tubular core 2, while one leg 12a and 12b of the magnet member 12 is mounted. ) Is arranged in the direction parallel to the transverse direction of the other legs 12a, 12b of the magnet member 12 and the tubular core 2.

In addition, as shown in FIG. 2, the deflection yoke 1 includes a magnetization coil 13 provided in each magnet member 12, and the magnetization coil 13 forms an example of magnetization means. The magnetizing coil 13 is wound around the middle leg 12a of each magnetizing member 12. The current flows through the magnetizing coil 13 to reduce the occurrence of sigal distortion in the image reproduced when the legs 12a, 12b of each magnet member 12 are polarized to predetermined poles, i.e., the north pole and the south pole. Each of the distortion compensation electromagnets 14 required in accordance with the present invention is composed of a magnet member 12 having respective magnetization coils 13 wound around the entire intermediate leg 12a.

The deflection yoke 1 of the configuration shown in FIG. 1 operates in the following manner.

FIG. 2 is a cross sectional view of the deflection yoke 1 in order to compensate for distortion when an electron beam traveling through the deflection electromagnetic field toward the fluorescent screen portion is deflected toward an edge region of the screen on the x axis perpendicular to the longitudinal axis of the cathode ray tube. How the distortion compensation electromagnet 14 operates. 3 is a sectional view seen from the front of the deflection yoke 1 and shows how the distortion compensation electromagnet 14 operates when the electron beam traveling in the deflection electromagnetic field is deflected toward the corner region of the screen below the x-axis.

As shown in FIG. 2, when a vertical deflection current of a predetermined polarity flows through the magnetizing coil 13, one of the magnet members 12, for example, the left magnet member 12 shown in FIG. The middle leg 12a of the side becomes an N pole, and the leg 12b becomes an S pole.

As a result, as shown by 11, the lines of magnetic force are looped from the middle leg 12a to one leg 12b and from the middle leg 12a to the other leg 12b. At the same time, the middle leg 12a of the right magnet member 12 becomes the S pole, and the leg 12b becomes the N pole. As a result, as shown by 11, the lines of magnetic force loop from the respective legs 12b to the middle legs 12a.

Therefore, three pairs of electron beams 70a and 70b, which are deflected toward the corner region of the fluorescent screen part spaced 2 / 3Xmax from the center, are upwards, i.e., away from the x-axis under the influence of upward biasing force. The deflection may be compensated so that the distortion of the sigal shape represented by (111) of FIG. 4 and the line reproduced on the screen coincide with the horizontal scanning line represented by the solid line 110 of FIG. Therefore, as shown in FIG. 5, the needle bar distortion appearing on both sides of the screen indicated by the virtual line A can also be compensated as shown by the solid line.

Where the electron beam is deflected toward the corner region of the fluorescent screen portion below the x-axis, the polarized rays are inverted by the inverted polarity of the vertical deflection current flowing through the magnetizing coil 13, so that the three electron beams 70c, 704 is similarly compensated for the line reproduced on the screen and the virtual line 111 of the sigal distortion by the downward deflection under the influence of the downward biasing force, as shown in the horizontal scan line 110 and FIG. The imaginary line A of the needle loop distortion coincides and can be compensated on both sides of the screen as indicated by the solid line.

The deflection force (1 Oy) may change simultaneously at the position where the three trillion electron beams are deflected so that when the three trillion electron beams travel along the x-axis as a result of the vertical deflection current, the deflection force (1 Oy) may be zero, but three When a pair of electron beams are deflected to any one of the four corner regions of the fluorescent screen portion, the deflection force 10y may increase in proportion to the square of the distance away from the center of the fluorescent screen portion in the x- and y-axis directions. Thus, as shown by 112a in FIG. 29, no protrusion phenomenon in the reproduced image occurs, and only the sigal distortion 111 in FIG. 4 is effectively compensated.

Each of the distortion-compensated electromagnets 14 may have various shapes as shown in FIGS. 6 to 8. In the example shown in FIG. 6 (a). Instead of using a single magnet coil wound around the middle leg of each magnet member 12 shown in FIGS. 1 to 3, two magnetizing coils 13a and 13b are used and the legs of each magnet member 12 are used. It is wound up at 12b.

In the example shown in FIG. 6 (b), the two magnetizing coils 13a and 13b are disposed between the middle leg 12a and one leg 12b, the middle leg 12a and the other leg ( Each part of the elongated body 12c of each magnet member 12 is wound between 12b).

In the example shown in Fig. 7 (a), each of the magnet members 12 is a leg 12b shown in any of Figs. 1 to 3, 6 (a) and 6 (b). And an arcuate body having the opposite end 120b, which has the function of a), and also having an intermediate leg 12a on which the magnetizing coil 13 is wound.

In the example shown in FIG. 7 (b). Each magnet member 12 has a quadrilateral cavity 213 to provide a pair of end walls 212b, a bottom wall 212c, and a pair of side walls 2126, and also a bottom wall 212c. It is composed of a quadrilateral body 212 having a projection (212a) protruding into the cavity (213) in the). The magnetizing coil 13 is located inside the cavity 213 of the quadrilateral body 212 and is wound around the protrusion 212a. In this structure, the end wall 212b and the projection 212a are intermediate with the legs 12b of the respective magnet members shown in FIGS. 1 to 3, 6 (a) and 6 (b). The functions of the legs 12a coincide with each other.

In the example shown in FIG. 8 (a), the legs 12b of each magnet member 12 are magnetized to the opposite poles, and the magnet members 12 become permanent magnets. The magnet member 12 according to the present example of FIG. 8 (a) is designed to exhibit the secondary effect as shown by the sieg distortion distortion magnet 10 used in the conventional deflection yoke shown in FIG. In the example shown in FIG. 8 (b), each magnet member 12 is not magnetized, while the permanent bar magnet 10 is fixed to the elongated body 12c of each magnet member 12.

By using the electromagnets 14 shown in FIGS. 8 (a) and 8 (b), the distortion on both sides of the screen resulting from the use of permanent magnets in combination with the magnet member 12 is shown in FIG. As described with respect to the conventional deflection yoke, the dotted line of FIG. 5 is consistent with the local needle thread distortion occurring at the upper and lower portions of the screen shown in FIG. It may be possible to change the needle bar distortion indicated by B). This change in needle holder distortion is a conventional technique that gently bends from top to bottom. Therefore, the compensation of the distortion by the conventional distortion compensation circuit can be easily achieved.

In the example shown in FIG. 9 (a), each magnet member 12 has the configuration shown in FIG. 6 (a), while different from that used in the magnet member 12 in FIG. Power supply circuits are used. The power supply circuit shown in FIG. 9 (a) is composed of a diode 15, and is designed to supply a vertical deflection current through only one of the magnetizing coils 13a and 13b so that the magnetic lines are only in the region where the electron beam is deflected. The other side of the magnetizing coils 13a and 13b does not work. In particular, the magnetizing coils 13 and 14 are provided only in the vertical deflection current for deflecting the electron beam upward with respect to the horizontal axis, and only in the acid vertical deflection current for deflecting the electron beam downward with respect to the horizontal axis. The magnetizing coils 13a and 13b may be wound around the elongated body 12c as shown in FIG. 6 (b).

In the example shown in FIG. 9 (b), each magnet member 12 is wound in a U-shaped body 312c having a leg 12b, and wound between the body 312c and intermediate between the legs 12b. It consists of a magnetizing coil 13 located at. Each magnet member 12 shown in FIG. 9 (b) is mounted to the tubular core 2 in a manner similar to that shown in FIG. 2, while the magnetizing coil 13 is a full-wave rectifier formed of a diode bridge network. (16) is connected to the source of the vertical deflection current.

The magnetic force line 11 generated by the configuration of the magnet member 12 shown in FIG. 9 (b) is similar to that generated by the magnet shown in FIG. 28, but the magnet member (shown in FIG. The magnetic force line generated in 12) changes as the vertical deflection current changes in such a way that the magnetic force becomes stronger as the electron beam is deflected up and down with respect to the x axis. However, when the electron beam travels along the x axis it will be zero. Therefore, the example of FIG. 9 (b) is effective in compensating for the sigal distortion without substantially involving the needle bar distortion with local protrusions as shown in FIG.

In the example shown in FIG. 9 (c), each magnet member 12 is composed of a rod having a long body 12c or an intermediate portion substantially around the magnetized coil 13 formed thereon. The magnetizing coil 13 is electrically connected to a source of vertical deflection current through a full wave rectifier 16 formed of a diode bridge network. The configuration of the magnet member 12 shown in FIG. 9 (c) can achieve an effect similar to that obtained by the magnet member 12 shown in FIG. 9 (b).

Although not shown, the configuration shown in FIG. 9 (b) may be modified such that each magnet member has two magnetizing coils wound around the leg 12b.

Another suitable embodiment of the present invention will be described with reference to FIGS. 10 to 18.

In Fig. 10 showing two embodiments of the present invention, 15 is fixed to one side of the elongated body 12c of the E-shaped magnet member 12 opposite to each of the legs 12a and 12b. The permanent bar magnet, which is longer than the long body 12c. The permanent bar magnet 15 of each E-shaped magnet member 12 has an N pole at the opposite end of one permanent bar magnet 15 and an S pole at the opposite end of the other permanent bar magnet 15. They are arranged in association with each other to face the S pole and the N pole, respectively.

According to the second embodiment of the present invention, the deflection yoke 1 using the permanent bar magnet 15 for each magnet member 12 operates in the following manner.

11 is a cross sectional view from the front of a given deflection yoke 1 along a plane perpendicular to the longitudinal axis of the tubular core 2 at the portion where the permanent bar magnet is located. As can be understood from FIG. 11, the loop of the magnetic force line 11 is combined by combining each permanent bar magnet 15 and the E-shaped magnet member 12. Occurs at each location indicated by. The effect of the loop of the magnetic field lines 11, i.e. Three pairs of electron beams 70b and 70a traveling in the vicinity of the position are deflected upwards by the biasing force 10y upwards, respectively. The three electron beams 70c and 70d traveling in the vicinity of the position are deflected downwards by the deflection force 10y. In addition, each of the deflection forces 10y increases as a quadratic function not far from the magnet member 12. Therefore, the segal distortion which may occur when three pairs of electron beams 70a and 70d are deflected diagonally with respect to the quadrangular fluorescent screen portion is well compensated.

Meanwhile, The magnetic field lines at each position marked with Since it is much smaller than the line of magnetic force at the position, the magnetic force affected by the three-pair electron beams 70e and 70f toward the x-axis and deflected inward of the x-axis can be significantly reduced, thus reducing needle-hold distortion and local protrusion. You can.

12 shows an example in which the E-shaped magnet member 12 carrying the permanent bar magnet 15 is fixed to the outer spherical surface 8c of the front end flange 8a of the separator 8 adjacent to the screen of the cathode ray tube. 10 shows that the magnet member 12 of FIG. 10 is fixed to the rear flange face of the front end flange 8a. This arrangement also achieves a similar effect by operating the synthetic deflection yoke 1 in a similar manner to the arrangement shown in FIG.

13 is a perspective view of the deflection yoke 1 according to the third embodiment of the present invention. The deflection yoke 1 according to these three embodiments is different from the deflection yoke 1 of the second embodiment shown in FIG. That is, although FIG. 10 uses an E-shaped magnet member 12, each of the magnet members 12 shown in FIG. 13 has a U-shaped shape including an elongated body 12c having only one pair of legs 12b. It is a magnet member 12.

As shown in FIG. 13, the operation of the deflection yoke 1 using the U-shaped magnet member 12 engaged with each permanent bar magnet 15 will be described with reference to FIG. 14 is a cross-sectional view from the front of the deflection yoke 1 given along a plane perpendicular to the longitudinal axis of the tubular core 2 where the U-shaped magnet member 12 with each permanent rod magnet 15 is located. .

As can be seen in FIG. 14, by coupling each permanent bar magnet 15 and the U-shaped magnet member 12, the loop of the magnetic force line 11 Occurs at each location marked with. By the effect of the loop of the magnetic field lines 11 Three pairs of electron beams 70a and 70b traveling near the position are deflected upwards by the biasing force 10y upward. The three electron beams 70c and 70d traveling near the position are deflected downward due to the downward biasing force 10y. As a result, as in the case of the deflection yoke 1 described in FIG. 11, the segal distortion is well compensated, and the occurrence of each of the needle bar distortion and the local protrusion is reduced.

As shown in FIG. 15, the U-shaped magnet member 12 carrying the permanent bar magnet 15 is fixed to the outer spherical surface 8c of the end face flange 8a of the separator 8 in a manner similar to that of FIG. have. This arrangement of FIG. 15 also causes the synthetic deflection yoke 1 to operate in a similar manner to the arrangement shown in FIG. According to a series of experiments, the use of the E-shaped magnet member 12 in the embodiment of FIG. 12 is closer to the x-axis (y = 0) than the use of the U-shaped magnet member 12 in the embodiment of FIG. 15. It has been found that the distortion of the magnetic field lines in E is significantly reduced, so that the distortion can be compensated more efficiently.

In the embodiment shown in FIG. 16, the deflection yoke 1 comprises a tubular core 2 made of ferromagnetic material such as ferrite, a horizontal deflection coil 3 and a vertical deflection coil 4, for example. The horizontal deflection coil 3 consists of a pair of saddle coils wound on the tubular core 2 and arranged opposite to each other with respect to the longitudinal axis of the tubular core 2, and generate an electromagnetic field necessary for deflecting the electron beam in the horizontal direction. . The horizontal deflection coil 4 generates an electromagnetic field necessary for deflecting the electron beam in the vertical direction.

According to this embodiment of the present invention, the vertical deflection coils 4 are tubular with the pair of main coils 4a, 4b which are wound on the tubular core 2 and arranged opposite to each other with respect to the longitudinal axis of the tubular core 2. And two pairs of auxiliary coils 4a-1, 4a-2 and 4b-1 and 4b-2 which are arranged symmetrically with respect to the x axis or the horizontal axis of the coil 2. The auxiliary coils 4a-1, 4b-1, 4a-2, and 4b-2 are located on each side of the pair of main coils 4a and 4b. The main coils 4a and 4b are positioned to develop at angles not greater than about 70 ° with respect to the y axis and the auxiliary coils 4a-1, 4a-2 and 4b-1 and 4b-2. The pairs are positioned to develop at an angle of about 65 ° to about 90 ° with respect to the y axis.

The deflection yoke 1 of the structure according to the embodiment shown in FIG. 16 operates in the following manner. 17 shows a direction in which current flows through each coil and a direction in which the electron beam is deflected. In Figure 17, the symbol And 을 indicate the flow of current through each coil and the direction of the electron beam 70, respectively. 18 shows the first upper limit of the Cartesian coordinate system shown in FIG. 17, i.e., the upper right upper limit, by superimposing the relationship of the deflection yoke 1 on the longitudinal axis of the tubular core 2 aligned at the origin of the Cartesian coordinate system. It is the figure which expanded the cross-sectional part of the deflected yoke 1 divided. The following description with reference to the first upper limit is equally applicable to the second to fourth upper limits of the Cartesian coordinate system.

In FIG. 18, three sets of electron beams 70 are connected to the magnetic force lines generated by the flow of current through the horizontal coil 3 and the current through the main coil 4a of the vertical deflection coil 4. As a result, when deflected upward in the diagonal direction as shown in FIG. 18, the three-piece electron beam 70 is caused by the magnetic force line 11 generated by the flow of current through the auxiliary coil 4a-1. It is affected by a force 10y directed upwards to the generated right. This upwardly directed force 10y becomes stronger as the distance from the x-axis increases, that is, as the electron beam 70 approaches the auxiliary coil 4a-1. Therefore, the sigal distortion shown in FIG. 26 can be compensated for.

Similarly, in the second, third and fourth quadrants not shown, three pairs of electron beams were affected by the force directed upward left, the force directed downward left, and the force directed downward downward. It can compensate for the sigal distortion shown in.

As a result of a series of experiments, the optimum region in which the auxiliary coils 4a-1, 4a-2, 4b-1, and 4b-2 are located is about 70 with respect to the Y axis to maximize the distortion compensation effect. We found that it was a zone. In addition, as a result of a series of experiments, the optimum region in which the main coils 4a and 4b are located is a region that is developed from 0 ° to about 60 ° on both sides with respect to the y axis so as to accompany a predetermined vertical deflection of the electron beam. Also found. Thus, in FIGS. 16 and 17, an angle of about 60 ° is shown on both sides with respect to the y axis. However, the area where the main coils 4a and 4b are located can be developed up to 70 °, and the appropriate area to avoid overlapping the auxiliary coil is reduced to an area that is developed from 0 ° to about 65 °.

Also, if the main coils 4a and 4b are positioned so as to overlap the auxiliary coils 4a-1, 4a-2, 4b-1 and 4b-2, the deflection effect caused by the main coils The bias effects caused by the and the auxiliary coils interfere with each other. Therefore, it is appropriate to avoid the position of the main coil when overlapping the relation of the auxiliary coils.

As mentioned above, although this invention was concretely demonstrated according to the Example, this invention is not limited to the said Example, Of course, a various change is possible in the range which does not deviate from the summary.

Claims (2)

Deflection used in the cathode ray tube 50 having the funnel portion 52 and the neck portion 53 and mounted on the cathode ray tube 50 at a position corresponding to the interface between the panel portion 52 and the neck portion 53. In the yoke (1), a fluorescent screen for the electron beam 70 is wound around the tubular core (2), the tubular core (2) and arranged symmetrically with respect to the longitudinal axis of the tubular core (2) and fired from the electron gun (54). A first deflection coil 3 which acts to deflect in the horizontal direction towards the part 100, wound around the tubular core 2 in an annular manner to act to deflect the electron beam 70 in the vertical direction, and Main winding means 4a, 4b positioned to extend at an angle not greater than 70 ° with respect to the direction; and auxiliary winding means 4a-1, 4a positioned to extend at an angle within the range of 65 ° to 90 ° with respect to the vertical direction. A deflection yoke comprising a second deflection coil (4) consisting of -2, 4b-1 and 4b-2). The deflection yoke of claim 1, wherein the main winding means is located within a range of 0 ° to 60 ° with respect to the vertical direction. A deflection yoke consisting of a tubular core and first and second deflection coils, in which a first deflection coil is wound around the tubular core and reduced in distortion on the curved screen of the SP panel of the cathode ray tube. The electron beams emitted from the electron gun, which are arranged symmetrically with respect to the longitudinal axis, are deflected horizontally toward the fluorescent screen portion, and the second deflection coil is wound in an annular shape on the tubular core to deflect the electron beams in the vertical direction. By doing so, the distortion appearing on the curved screen of the panel of the cathode ray tube can be reduced.