JPH1012157A - Deflection yoke for color CRT - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve distortion without degrading convergence characteristics and reduce leakage magnetic flux by providing a horizontal deflection coil with a folded part or additional winding. SOLUTION: A funnel 15 of a color CRT of a self-convergence method having an inline electron gun is provided with a vertical deflection coil 12 and a horizontal deflection coil 14. That is, for a deflection coil 10, the vertical deflection coil 12 is wound around a winding frame 11, and the horizontal deflection coil 14 is wound around a winding frame 13. And, the horizontal deflection coil 14 is provided with a folded portion 16 at which a winding of a screen side crossing portion is folded back on a neck side. In addition, a neck portion of the horizontal deflection coil 14 is provided with an additional winding 19 in the same winding direction. Thus, a convergence is improved over a screen front face without degrading a horizontal deflection sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a deflection yoke constituting a color CRT having an in-line type electron gun.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram of a deflection yoke described in Japanese Unexamined Patent Application Publication No. H11-209,004. In the drawing, a deflection yoke 1 has a structure having horizontal deflection coils 5, 6, 7 via coil frames 2, 3, 4. The vertical deflection coils 8 and 9 are arranged inside the core 10.

Next, the operation of the prior art will be described. In the description, the principle of the function of the deflection yoke and the functions to be performed will be described, and the functions performed by the conventional example will be described. 1) Function of deflection yoke The deflection yoke of the color CRT has a function of not only deflecting three electron beams to each point on the screen but also converging three beams at each point on the screen. This function is called a self-convergence function. This is a function necessary for colorization, and converging to one point is a function necessary for increasing color purity.

Now, a magnetic field distribution required to satisfy this function will be described. Consider the case where the beam goes to the center of the screen. In this case, there is no magnetic field generated by the deflection yoke. However, even in this case, the lens (electrode shape) of the electron gun is designed so that the beams exit at an angle to each other at the exit of the electron gun so that the three beams converge on the screen at one point.

Consider what happens when the beam taken out of the electron gun designed as described above is deflected by the deflection yoke. When the beam is bent by the deflection yoke, the distance of the beam trajectory to the screen is longer than that at the center of the screen.

For this reason, when the beam is simply bent, a center beam (hereinafter, referred to as a G beam) is provided in front of the screen.
And both side beams (hereinafter referred to as R beam or B beam) cross each other, and do not converge on the screen. This means that there is no predetermined color from the viewpoint of the observer.

In order to solve this problem, the deflection yoke generates a magnetic field which deflects in the horizontal direction and becomes stronger as the distance from the center axis increases. This magnetic field distribution is usually called a pincushion magnetic field, and a magnetic field in the opposite direction (a gradually weakening magnetic field) is called a barrel magnetic field. As a method for generating such a magnetic field distribution, a method of adding a six-pole magnetic field component to a uniform magnetic field is generally used. The magnetic field distribution generated by this method has a pincushion (X-shape) or bar-shaped magnetic field line. It is thus called because it is distorted (O-shaped).

[0008] When this field is generated, the outer beam, for example, passes through a stronger magnetic field and thus undergoes greater deflection, and the inner beam passes through a smaller magnetic field, for example, as compared to the G beam. It will be deflected. As a result, the R and B beams are less likely to intersect the G beam in front of the screen.

By making the action of the magnetic field appropriate, it becomes possible to converge the three beams of R, G and B at one point on the screen.

However, as described above, it is not possible to collect three beams at one point only by appropriately selecting the pincushion magnetic field distribution. This is because the degree of freedom of adjustment is smaller than the constraint condition. For example, even if the convergence effect of the R and B beams on both sides is ensured, the central G beam will be deviated therefrom.
This error is called coma aberration. For this reason, generally, a barrel magnetic field in the direction opposite to the screen-side pincushion magnetic field is generated at the neck of the deflection yoke. Since this barrel magnetic field is a kind of hexapole magnetic field, the beam trajectory almost passes on the central axis as in the vicinity of the neck.
It does not act on the beam, but acts on the R and B beams separated to the left and right in the direction that matches the G beam.
By adjusting this magnetic field, it is possible to collect three RGB beams at one point on the screen in combination with the above-described pincushion magnetic field on the screen side.

Next, consider the case of deflection in the vertical direction. Also in this case, as in the case of the horizontal deflection described above, three lines intersect in front of the screen only with a uniform magnetic field. In this case, a barrel magnetic field is generated. When three beams extracted from the in-line type electron gun pass through the barrel magnetic field, both side beams receive a force that spreads in the horizontal direction with respect to the center beam. As a result, convergence can be secured on the screen.

As a function required for the deflection yoke, in addition to the above, there is a function of making the shape of drawing on the screen (also called a raster shape) a shape without distortion. Raster-shaped distortion usually shows a tendency for the raster interval to open up and down at the left and right edges of the screen, and is generally called upper and lower pincushion distortion. To correct this distortion, it is generally effective to arrange the vertical deflection center on the neck side of the horizontal deflection center.

The reason is as follows. The six-pole magnetic field for generating the pincushion magnetic field for self-convergence described above is represented by the following equation. _{B x α xy B y α x} 2 -y 2 Here x, y is the position coordinates on the screen. Here, the magnetic field component effective for correcting the raster shape distortion is B
an _x, but effective magnetic field component in the convergence sense is B _y, the action of B _x compared to B _y is insufficient is causing raster distortion. Here, when the vertical deflection center is arranged on the neck side, the value of y (absolute value) increases, so that B
effect of _x unbalance of the is eliminated is larger than the action of B _y. However, this method has another problem that the entire length of the deflection yoke is long.

From the above viewpoint, the magnetic field distribution generated by the deflection yoke is generally as follows. The horizontal deflection magnetic field generates a barrel magnetic field on the neck side and a pincushion magnetic field on the screen side. The vertical deflection magnetic field generates a barrel magnetic field. Furthermore, the center of deflection of the horizontal deflection magnetic field is set closer to the screen than the center of deflection of the vertical deflection magnetic field, so that raster distortion on the screen is reduced.

Next, functions required for the deflection yoke other than the screen characteristics will be described. First, the leakage magnetic flux will be described. Leakage magnetic flux is generated for the following reasons. When an electric current is applied to the horizontal deflection coil, a magnetic charge is induced in the magnetic material constituting the deflection yoke. In the vicinity of the deflection yoke, the magnetic charge and the magnetic flux generated by the coil are effective for deflecting the electron beam. However, at a position distant from the deflection yoke, the magnetic flux density created by the magnetic material and the magnetic flux density created by the coil have directions opposite to each other and cancel each other. If this cancellation is sufficient, the leakage magnetic flux will be zero, but in general, a certain amount of magnetic flux density will remain because the magnetic flux density created by the core is high.

The leakage magnetic flux is regulated so as to be less than a predetermined value due to environmental problems (MPR-2 standard). For this purpose, conventionally, a coil for canceling the leakage magnetic flux is attached to the deflection yoke so that the deflection yoke is kept below a predetermined level.

Another problem other than the screen characteristics is power consumption. Since the deflection yoke generates an alternating magnetic field, a very large amount of reactive power is required. The loss of the circuit that generates this power reaches several tenths of the entire CRT. It is necessary to reduce power consumption from the viewpoint of environmental problems.

Further, a value called BSN tolerance must be set to a predetermined value or more due to the influence of tolerance in CRT assembly. The BSN tolerance means that the deflection yoke is set to C under the condition that the beam is deflected to a specified screen size on the screen.
This is the maximum range in which the beam can move without colliding with the funnel inner wall when moved in the RT axis direction. If the current deflection yoke does not secure a certain BSN margin, the yield in assembling will be degraded. This is because the production accuracy of funnel glass is not very high at present.

This problem is a major obstacle to the difference in power consumption reduction. In order to reduce the power consumption of the deflection yoke, the deflection yoke should be located as far as possible from the screen. That is, the more the light is deflected at the rear, the more advantageous the sensitivity. However, there is a limit due to the problem of the BSN margin described above.

In order to solve the leakage magnetic flux, there arises a problem of deflection sensitivity. As described above, in order to improve the leakage magnetic flux, it is common practice to mount a leakage magnetic flux elimination coil. However, since the leakage magnetic flux elimination coil is connected in series with the horizontal deflection coil, attaching the coil increases the inductance of the deflection yoke and deteriorates the deflection sensitivity. Therefore, a problem to be solved in the leakage magnetic flux elimination coil is to devise a system in which cancellation is efficiently performed without increasing inductance.

The above is the general description of the deflection yoke. Next, the prior art document attached to the reference material relates to the above-mentioned problems imposed on the deflection yoke, particularly, measures against distortion.

In the present technology, a part of the coil at a portion called a transition portion along the edge of the core on the screen side of the horizontal deflection coil is folded back to the neck side, thereby increasing the pincushion component of the horizontal magnetic field on the screen side and deflecting. It tries to solve the distortion.

[0023]

According to the above-mentioned prior art, distortion can be improved, but the following problems occur. In order to improve the distortion on the screen side, the pincushion magnetic field must be increased. However, if it is attempted to remove distortion only by folding winding as in the conventional example, the horizontal deflection magnetic field on the screen side is weakened, the center of horizontal deflection moves to the electron gun side, and convergence characteristics around the screen deteriorate.

An object of the present invention is to solve such a problem, improve distortion without deteriorating convergence characteristics, and obtain a deflection yoke with small leakage magnetic flux.

[0025]

According to a first configuration of the present invention, in a deflection yoke of a self-convergence type color CRT having an in-line type electron gun, a winding of a horizontal deflection coil at a screen side transition portion is folded back to a neck side. A folded portion is provided, and an additional winding in the same winding direction is provided at the neck of the horizontal deflection coil.

According to a second aspect of the present invention, in a deflection yoke of a self-convergence type color CRT having an in-line type electron gun, a folding portion is provided by folding a winding of a horizontal deflection coil at a screen side transition portion to a neck side, An additional winding in the same winding direction is provided at the center of the horizontal deflection coil.

According to a third configuration of the present invention, the winding frame for locking the winding of the horizontal deflection coil folded portion is arranged such that the position of the rib for locking the winding is axially toward the screen in the winding order. It is going forward.

According to a fourth aspect of the present invention, the winding of the folded portion of the horizontal deflection coil is provided outside the core.

According to a fifth aspect of the present invention, there is provided a leakage magnetic flux elimination coil which is provided outside the core on the deflection yoke screen side and has a structure in which the end is bent toward the inside of the core.

According to a sixth aspect of the present invention, there is provided a magnetic flux elimination coil which forms a closed current loop independently of the horizontal deflection coil and is arranged at a screen-side tip of the core at a position interlinked with the magnetic flux leakage. It is provided.

In a seventh aspect of the present invention, the gap between the horizontal deflection coil and the core is larger on the screen side than on the neck side.

According to an eighth aspect of the present invention, the horizontal deflection coil winding frame is provided with a recess for accommodating a rib of the vertical deflection coil winding frame.

According to a ninth aspect of the present invention, the deflection yoke is provided with an octupole magnetic field generating coil driven by a DC power supply.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 shows a basic configuration of the first embodiment. In the drawing, reference numeral 10 denotes a core constituting a deflection yoke, 11 denotes a winding frame of a vertical deflection coil, 12
Indicates a vertical deflection coil. Reference numerals 13 and 14 denote a winding frame of the horizontal deflection coil and the horizontal deflection coil. Fifteen
Denotes a glass tube, and 16 denotes a folded horizontal deflection coil. Reference numeral 17 denotes a spacer between the core and the vertical deflection coil frame.

FIG. 2 is a schematic view of the horizontal deflection coil when the deflection yoke of the first embodiment is viewed from the screen side. For simplification, the vertical deflection coil and the winding frame are omitted in FIG. Also, the winding frame of the horizontal deflection coil is omitted. However, the rib at the position where the angle of the winding changes is indicated by 18 in the figure. As shown in the figure, the horizontal deflection coil has a part of the winding extending to the vicinity of the screen,
After that, it turns out that it is folded in the reverse direction according to the rib of the winding frame. Hereinafter, this portion is referred to as a “return portion”.
The position of the folded portion in the present embodiment is the same as that of the prior art (FIG. 24).
Is closer to the screen side than the unwinding part. 19 is a winding of a horizontal deflection coil added from the neck to the center of the deflection yoke. This winding direction is the same as that of the horizontal deflection coil.

This embodiment can improve deflection sensitivity and is effective in improving distortion. First, what kind of magnetic field is generated when such a winding is provided will be described.

The cross section of the deflection yoke is as shown in FIG. In the figure, a region 20 is a neck portion or a center portion of the deflection yoke where the additional winding 19 of the horizontal deflection coil is present, and a portion 21 is a portion where a folded portion on the screen side is present.

In the region indicated by reference numeral 20 in FIG. 3, current in the same direction is applied to the horizontal deflection coil in all quadrants. For this reason, a magnetic field exists even at a position distant from the coil (for example, on the center axis), and the beam passing near the neck can be deflected.

On the other hand, a reverse current also exists in the region 21 due to the folded portion. Since currents in the forward and reverse directions are supplied to the normal coil and the coil of the folded portion, the magnetic field at a position distant from the coil decreases rapidly.
Therefore, in the region 21, the magnetic field exists only near the coil, and the magnetic field is weak near the central axis. However, in this area, the beam passes through a position further away from the axis, so that the magnetic field required for deflection can be supplied.

Next, the following three effects (improvement of distortion, improvement of deflection sensitivity, improvement of leakage magnetic flux) will be described.

1: Effect of Correcting Distortion A mechanism for improving distortion by a horizontal deflection magnetic field will be described. The horizontal deflection magnetic field mainly includes a uniform magnetic field component and a six-pole magnetic field component. The six-pole magnetic field component is also called a third-order component, and the potential of the horizontal deflection magnetic field is cos (3
θ) component. The generated magnetic field is described by _{B x α xy B y α x} 2 -y 2.

B _{x in the} magnetic field is a component for deflecting the beam up and down. If B _x is positive, for example, when deflecting the beam to the upper right end of the screen, the beam is pushed down to improve the distortion. Have.

Therefore, the stronger the six-pole magnetic field component is, the more the distortion is improved. In the present embodiment, since the forward and reverse currents flow in the region 21, it is possible to generate a six-pole magnetic field component stronger than in the past, and the distortion correction is more advantageous than in the past.

[0044] Further, in the present embodiment has arranged the folded portion more on the screen side compared to the prior art examples shown, x than the conventional, y since has become a large value above B _x is a value greater Becomes That is, a large distortion correction effect can be obtained with a small rewind.

On the other hand, regarding the contribution to convergence, B
One-time differentiation of _{y in} the x direction is an index indicating the effect. Therefore, in this case, it is proportional to x. In the related art, when the distortion correction is sufficiently performed, there is a problem that the action of the six-pole magnetic field becomes too strong for the convergence, but the distortion correction is proportional to the square of the position like xy. Therefore, the convergence characteristic is an amount proportional to the first power, so in the case of a horizontal deflection coil extending on the screen side,
The effect of improving the distortion characteristic appears more strongly with respect to the change in the convergence characteristic, and both distortion correction and convergence can be achieved.

2: Effect of Improving Deflection Sensitivity Next, the reason why the deflection sensitivity is improved in the present embodiment will be described. The trajectory of the electron beam that has received the deflection magnetic field passes through a position far away from the axis near the exit of the deflection yoke (region 21).

In the winding of the present embodiment, the generated magnetic field has a strong six-pole magnetic field component, and the magnetic field increases as the distance from the axis increases. Therefore, even if a necessary magnetic field is generated on the beam trajectory, the magnetic field on the central axis can be reduced as compared with the conventional winding.

The deflection sensitivity is represented by the magnetic field energy required to deflect the beam in the space. If the magnetic field can be generated only in the necessary portion as described above, the total magnetic field energy in the space can be reduced. And the deflection sensitivity is improved.

As described above, according to the present embodiment, both distortion correction and convergence can be achieved, and the deflection sensitivity can be improved.

3: Improvement of Leakage Flux In the configuration of the present embodiment, it is possible to reduce the leakage flux at the same time. In the present embodiment, as shown in FIG. 1, the horizontal deflection coil is disposed so as to cover the folded portion. The reason why the leakage magnetic flux is reduced by this will be described.

As described above, the cause of the generation of the leakage magnetic flux is the magnetic charge induced in the core. The actual leakage magnetic flux is formed as a value in which the magnetic flux density generated by the horizontal deflection coil is canceled to some extent. The cause of the magnetic charge depends on the magnetic flux density created by the coil.

A magnetic charge is induced on the surface of the core by the magnetic flux generated by the coil. FIG. 4A shows the relationship between a conventional horizontal deflection coil and a core. 2 in the figure
2, 24 indicate the distribution and polarity of the magnetic charge induced in the core, 22 indicates a negative region, and 24 indicates a positive region. Reference numeral 23 indicates the direction of the magnetic field generated by the core. The horizontal deflection coil has a structure protruding from the core. Therefore, the direction of the magnetic flux on the core generated by the coil is always the same direction. In this case, as shown in the figure, a magnetic charge of the same polarity (negative polarity in the figure) is induced on the entire surface of the core. Become.

FIG. 4B shows the relationship between the core and the horizontal deflection coil in the present embodiment. A horizontal deflection coil is disposed so as to cover the tip of the core (the vicinity of the coil 16 is shown). In this case, as shown in the figure, a magnetic charge of the same polarity as that of the related art is induced on the rear side with respect to the tip of the horizontal deflection coil, but the opposite polarity (positive polarity in the case of the figure) is generated on the screen side. The load is induced, and the magnetic flux is short-circuited and does not leak outside. Further, since the core and the distal end of the horizontal deflection coil are separated from each other, the magnetic charge generated at the cross section of the horizontal deflection coil can be reduced.

Since the cause of the leakage magnetic flux is the magnetic charge induced in the core, the amount of the leakage magnetic flux is reduced when the magnetic charge of the opposite polarity is induced in the core as shown in FIG. Becomes possible. Therefore, in this embodiment, since the absolute amount of the leakage magnetic flux can be reduced, the load on the leakage magnetic flux elimination coil can be reduced, and as a result, the deflection sensitivity index can be improved.

Embodiment 2 FIG. 5 shows the configuration of the second embodiment of the present invention. In the drawing, reference numeral 32 denotes a part of a horizontal deflection coil arranged at the center of the deflection yoke. FIG. 6 is a view of the horizontal deflection coil as viewed from the screen side.

In this embodiment, the coil disposed at the center is connected in series with the horizontal deflection coil in the same direction. In the case of the folded winding shown in the first embodiment, there is a problem that the center of horizontal deflection moves to the neck side. In this case, there is a problem in terms of BSN margin.

In the present embodiment, by arranging a part of the horizontal deflection coil at the center of the deflection yoke, the center of horizontal deflection can be moved to the screen side to solve the problem of BSN tolerance. Regarding the deflection sensitivity index, since the magnetic field generated by the present coil is limited to the region where the inner diameter of the core is small, there is no deterioration in sensitivity.

The convergence characteristics can be improved by using the present coil.

The grounds for improving the convergence characteristics will be described below. A numerical value called a trilemma exists as an index indicating the uniformity of the convergence characteristic over the entire screen. The trilemma is represented by the following equation. Trilemma = XH-YH + PQ _V The smaller the value, the better the convergence over the entire screen. Here, XH indicates the horizontal distance between the B beam and the R beam at the horizontal end of the screen. When the R beam exists on the right end of the screen on the right side of the B beam, it becomes a negative sign. The sign of However, the beam emitted from the electron gun is in the order of BGR from the right toward the screen.

Further, YH is the B beam and R at the upper and lower ends of the screen.
It indicates the horizontal distance between the beams, and is a negative sign when the R beam exists on the right side of the B beam at the upper end of the screen, and has a positive sign when it exists on the left side.

PQ _V indicates the vertical distance between the B beam and the R beam at the screen corner, and a negative sign when the R beam is located above the B beam at the upper right end of the screen toward the screen. And a positive sign if it exists below.

The above is the description of the trilemma. It is known that in a normal deflection yoke, this value takes a substantially constant value even if the winding distribution is simply changed, unless the winding shape is basically changed. Also, it is generally known to take a negative value.

According to this embodiment, it is possible to move the center of horizontal deflection to the screen side more than usual.
In this case, the electron beam near the neck is first deflected vertically and then deflected horizontally.

When a pincushion magnetic field of the horizontal deflection magnetic field exists near the neck, if the beam is deflected to the upper right of the screen, the R beam is vertically deflected and the right beam is affected by the pincushion magnetic field of the horizontal deflection magnetic field. It will receive a downward force.

On the other hand, the B beam receives a force in the upper right direction similarly due to the influence of the pincushion magnetic field. These forces act in the direction of improving the PQ _V. Since this magnetic field is a force acting when both horizontal and vertical magnetic fields are present, X
H and YH are not affected. Therefore, the trilemma can be corrected in the positive direction, and the convergence characteristics can be improved.

Embodiment 3 FIG. 7 shows the configuration of the third embodiment of the present invention. In the drawing, reference numerals 33 and 34 denote positions of ribs for constituting the crossover portion.

This embodiment relates to a rib structure for forming a transition portion at the center of the deflection yoke.

As shown in FIG. 7, it is obvious that automatic winding cannot be performed due to the structure of the winding machine unless the position of the rib, which is the base point for forming the crossover portion, is made different in the axial direction.

However, by setting the circumferential angles of the ribs to be different from each other as shown in the figure, it is possible to create a space that does not hinder the winding machine even if the space in the axial direction is small. Becomes possible.

Therefore, according to the present invention, the folded coil can be formed as deep as possible, and the coil disposed at the center can be made large. This facilitates implementation of the first and second embodiments.

Embodiment 4 FIG. 8 is a diagram showing the configuration of the fourth embodiment of the present invention, and shows a quarter quadrant of the deflection yoke as viewed from above. In the drawing, reference numeral 30 denotes a winding frame of a horizontal deflection coil for forming a transition portion.
Reference numerals 25, 26, and 27 indicate horizontal deflection coils. 2
Numerals 8 and 29 indicate the directions of the current flowing in the coil. FIG. 9 shows 1 /
The cross section of four quadrants is shown. FIG. 10 is an explanatory diagram of a winding method for performing insulation measures.

This embodiment relates to a measure against insulation associated with the folded winding shown in the first embodiment. The operation will be described with reference to the drawings.

First, problems concerning insulation will be described. A high frequency current of about 100 kHz is passed through a normal horizontal deflection coil. Since this high-frequency current is supplied, a potential difference of about 1 kV is generated between the entrance and the exit of the coil.
In order to avoid the discharge due to the potential difference, a normal winding employs a laminated winding in which the potential difference between adjacent windings is as small as possible, as shown in FIG.

FIG. 10 (b) shows a case where the winding is performed in a folded state.
As shown by the folded winding, a portion where the windings cross each other occurs, which is a weak point on insulation. ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to wire so that each layer may not cross using the winding frame which comprises a transition part, and the weak point with respect to insulation is eliminated.

In FIG. 8, coil numbers 25, 26, 27
It is assumed that they are wound in this order. As shown in FIG. 8, the structure of the winding locking ribs of the winding frame is
If the positions of the ribs advance in the axial direction toward the screen in accordance with the order of the windings 6 and 27, the winding can be folded back without the windings crossing each other.

Embodiment 5 FIG. 11 is a view showing the configuration of the fifth embodiment of the present invention, and shows a quarter quadrant of the deflection yoke as viewed from above. In the figure, reference numeral 31 denotes a winding frame of a horizontal deflection coil for forming a transition portion.

FIG. 12 shows a section of a quarter quadrant of the deflection coil as viewed from the screen side. The broken line in the figure indicates that the coil is wired behind the core.

This embodiment relates to a measure against insulation associated with the folded winding shown in the first embodiment. The operation will be described with reference to the drawings.

FIG. 11 is a view of the cross section of the deflection yoke on the screen side as viewed from above. As shown in the figure, the winding that has passed through the winding frame attached to the screen side of the deflection yoke forms a crossover outside the deflection yoke. FIG.
Is a view as viewed from the screen side, and the coils shown by solid and broken lines. The broken-line coil indicates that the coil is wound around the core. As shown in the figure, the winding of the transition part is provided outside the core,
It has the same shape as it should be and can generate a desired magnetic field.

Next, insulation will be described. As shown in FIG. 11, in the present winding, the windings of the respective layers are folded back without intersecting with each other as in the laminated winding in consideration of insulation shown in FIG. Therefore, the problem of the insulating state has been solved.

Embodiment 6 FIG. FIG. 13 is a diagram for explaining the configuration and operation of the sixth embodiment of the present invention. In FIG. 13, reference numeral 35 denotes a leakage magnetic flux eliminating coil disposed on the exit side of the deflection yoke. Numeral 23 indicates the distribution of the conventional lines of magnetic force generated by the deflection yoke.

FIG. 14 shows the shape of the leakage magnetic flux erasing coil and the state of generated magnetic lines of force. Numeral 37 indicates the state of the magnetic force lines generated by the leakage magnetic flux coil according to the present embodiment. FIG. 15 shows the state of the lines of magnetic force when the deflection yoke and the leakage magnetic flux canceling coil are combined. In the drawing, the lines of magnetic force generated by the leakage magnetic flux eliminating coil are indicated by thick lines. FIG. 16 shows the distribution of the magnetic flux density generated by the leakage magnetic flux eliminating coil. A solid line 38 in the drawing indicates a contour line of the magnetic field.

As shown in FIG. 14, the leakage magnetic flux eliminating coil in the present embodiment has a structure bent in the axial direction on the screen side.

The leakage magnetic flux density generated by the deflection yoke has a strong distribution on the screen side and a weak distribution on the neck side since the shape of the deflection yoke is open on the screen side. Conventionally, in order to cancel this magnetic field, the coil is turned several times on a plane, and a horizontal deflection current is applied.

In this case, there is an excess or deficiency in the elimination of the leakage magnetic flux, and the magnetic flux density on the screen side is canceled to some extent.
The magnetic flux density on the neck side was excessively canceled and the standard was cleared as an absolute value. In this case, an excessive current is applied to the coil, which causes deterioration of the deflection sensitivity index.

In this embodiment, the shape of the coil for eliminating leakage magnetic flux is not a conventional flat type, but has a structure shown in FIGS. The magnetic field generated by the coil is stronger in the forward direction than in the rear due to the effect of the bent portion of the coil. Therefore, as shown in FIG. 16, the cancel magnetic field generated by this coil can be made stronger on the screen side and weaker on the neck side. Therefore, the leakage magnetic flux can be canceled without excess and deficiency, and the deterioration of the deflection sensitivity index can be prevented.

Embodiment 7 FIG. 17 is a diagram for explaining the configuration and operation of the seventh embodiment of the present invention. In FIG. 17, reference numeral 10 denotes a core constituting the deflection yoke. Reference numeral 39 denotes a leakage magnetic flux eliminating coil according to the present embodiment. Numeral 40 indicates a deflection magnetic field generated by the deflection yoke. Reference numeral 41 indicates the direction of the current flowing through the leakage magnetic flux erasing coil. In the present embodiment, a closed current loop linked to an AC leakage magnetic field is provided, and a leakage magnetic flux is canceled by a demagnetizing field generated by the closed current path.

In the present embodiment, when the horizontal deflection magnetic field has a magnetic flux density 40 from top to bottom as shown in FIG. 17, an induced current 41 is induced in the coil in the direction shown in the figure. The induced current has a direction to cancel the magnetic field 40 generated by the deflection yoke. In the case of this system, the energy applied to the leakage magnetic flux erasing coil 39 is supplied from the leakage magnetic field of the magnetic field generated by the deflection yoke, and therefore does not lead to an increase in the load on the power supply. Therefore, it is possible to reduce the leakage magnetic flux without deteriorating the deflection sensitivity.

Embodiment 8 FIG. FIG. 18 is a view for explaining the configuration of the eighth embodiment of the present invention. In FIG. 18, reference numeral 42 shown in FIG. 18B indicates a core constituting the deflection yoke in the present embodiment. Reference numeral 14 denotes a horizontal deflection coil. FIG. 18A shows a relationship between a conventional core and a horizontal deflection coil. In the present embodiment, the gap between the horizontal deflection coil 14 and the core 42 is increased on the screen side.

In this embodiment, when there is a gap between the core and the coil constituting the deflection yoke as shown in FIG. 18, any effect can reduce the leakage magnetic flux, and as a result, the deflection sensitivity index of the system is improved. I will explain.

As shown in FIG. 13 and the like, in the vicinity of the deflection yoke, the lines of magnetic force generated by the coil and the lines of magnetic force generated by the magnetization of the core are in the same direction and deflect the electron beam by strengthening each other.

On the other hand, the regulated leakage magnetic flux is a value at a distance of 50 cm from the screen. In this vicinity, the lines of magnetic force of the core and the lines of magnetic force of the coil have opposite directions, but the strength of the lines of magnetic force of the core is stronger. Therefore, if the magnetic charge generated in the core is weakened, the leakage magnetic flux can be reduced.

Next, how the magnetic charge induced in the core is generated will be described. The source of the magnetic charge induced in the core is the coil. Magnetic charge is induced in the core by the magnetic field generated by the coil. Therefore, moving the core away from the coil will reduce the magnetic charge. In this case, the generated magnetic charge is reduced, so that the magnetic field for deflecting the beam is also weakened, and the deflection sensitivity is degraded.

However, when the electron beam is deflected as a function of the deflection yoke, the main portion of the generated magnetic field exists in the neck portion (for example, near 20 in FIG. 3) and in the vicinity of the screen (for example, near 21 in FIG. 3). In (), the generated magnetic field is very weak. Therefore, even if the inner surface of the core on the screen side is separated from the coil, the deterioration of the deflection sensitivity index is small. In addition, the magnetic charge that contributes to the leakage magnetic flux is generated on the screen side of the core, and it is possible to reduce the leakage magnetic flux by reducing the magnetic charge on the screen side. , The reduction of the deflection sensitivity index can be avoided.

Embodiment 9 FIG. FIG. 19 is a diagram showing the configuration of the ninth embodiment of the present invention, in which the neck portion of the deflection yoke in the winding frame structure is enlarged. In the figure, reference numeral 43 denotes a winding frame of the horizontal deflection coil according to the present embodiment, and reference numeral 44 denotes a transition portion of the horizontal deflection coil. Reference numeral 45 denotes an insulating plate for the horizontal deflection coil and the vertical deflection coil. Reference numeral 46 denotes a rib constituting a transition portion of the vertical deflection coil, and reference numeral 47 denotes a transition portion of the vertical deflection coil. Reference numeral 48 denotes a frame for taking insulation between the vertical deflection coil and the core. FIG. 20 is a view of the portion 46 viewed from the neck direction. FIG. 21 shows a structure in which 45 members are viewed from the screen direction.

Next, the operation of the present embodiment will be described. An object of the present embodiment is to improve the deflection sensitivity by reducing the portion of the horizontal deflection coil constituting the deflection yoke that protrudes from the core as much as possible to reduce the leakage magnetic field.

In the vicinity of the end of the conventional deflection yoke, space for the following components was required. 1: a rib structure portion 43 constituting a cross section of a horizontal deflection coil 2: a cross section 44 of a horizontal deflection coil 3: an insulator 454 for maintaining insulation between the horizontal deflection coil and the vertical deflection coil 4: The rib structure portion 465 constituting the transition portion: the transition portion 47 of the vertical deflection coil If the portions 3, 4, and 5 of these components are made smaller, the gap between the horizontal deflection coil and the core becomes smaller, so that it goes to the outside. And the deflection magnetic field can be effectively used.

In this embodiment, as shown in FIGS. 20 and 21, a depression is provided so that the 46 rib structure portion is fitted into the 45 insulating plates (oblique hatched portions in the drawings).

Therefore, according to the present embodiment, the rib structure 4
6 can be built into the insulating plate 45, and the space of the above-mentioned items 3 and 4 can be reduced, and as a result, the deflection sensitivity can be improved.

Embodiment 10 FIG. FIGS. 22 and 23 are views for explaining the configuration and operation of the tenth embodiment of the present invention.
FIG. 22 shows an eight-pole coil provided on the deflection yoke in the present embodiment. In the figure, reference numeral 49 denotes a winding of an 8-pole coil. Numeral 50 indicates magnetic lines of force generated by the 8-pole coil. FIG. 23 shows the force received by the electron beam. In the figure, reference numerals 51, 52, and 53 indicate RGB beams, respectively.

The lines of magnetic force shown in FIG. 22 are generated inside the deflection yoke by the present electromagnet. According to the present embodiment, the electron beam receives a force in the direction shown in FIG. The direction of the force depends on the position of the electron beam.

In the case of the figure, the direction of the force is R at the horizontal end of the screen.
A force for shrinking the space between B acts. In this case, the trilemma index XH changes to plus. At the vertical end, it becomes a force to separate the RB. In this case, YH acts negatively.
Therefore, it acts positively as a trilemma. In the upper right corner of the screen, the RBs are separated in the horizontal direction, and R in the vertical direction.
Has the effect of making B higher than B. Therefore, PQ _V
Works negatively.

The result is a force acting on the above-described trilemma in the positive direction, and the convergence characteristics of the screen are improved.

[0104]

As described above, according to the first configuration of the present invention, the winding of the horizontal deflection coil at the screen side transition portion is turned back to the neck side, and the same winding direction is added to the neck portion of the horizontal deflection coil. Since the winding is provided, convergence and distortion can be improved without lowering the horizontal deflection sensitivity. Also, the leakage magnetic flux can be reduced.

Further, in the second configuration of the present invention, the winding of the horizontal deflection coil at the screen side transition portion is folded back to the neck side, and an additional winding in the same winding direction is provided at the center of the horizontal deflection coil. Therefore, in addition to the effects of the first configuration, the trilemma index is improved, and convergence is improved over the entire screen.

In the third and fourth configurations of the present invention, the positions of the winding locking ribs at the folded portions of the horizontal deflection coil winding frame are advanced in the axial direction toward the screen in the winding order. Therefore, the occurrence of a cross portion in the winding is avoided, and the problem of insulation is reduced.

Further, in the fifth configuration of the present invention, since the tip of the leakage magnetic flux erasing coil is bent toward the inside of the core distal end, the erasing magnetic flux density is higher on the screen side where the leakage magnetic flux density is higher. Can be increased, and cancellation without excess or deficiency can be performed according to the distribution of the leakage magnetic flux density.

Further, in the sixth configuration of the present invention, a closed current loop is formed independently of the horizontal deflection coil, and a leakage magnetic flux elimination coil disposed at a position linked to the leakage magnetic flux at the screen-side tip of the core. Since no power supply is required for eliminating the leakage magnetic flux, the leakage magnetic flux can be canceled without lowering the deflection sensitivity.

Further, in the seventh configuration of the present invention, since the gap between the horizontal deflection coil and the core is made larger on the screen side than on the neck side, it is possible to reduce the leakage magnetic flux without lowering the deflection sensitivity. .

In the eighth configuration of the present invention, the horizontal deflection coil winding frame is provided with a recess for accommodating the rib portion of the vertical deflection coil winding frame, so that the horizontal and vertical deflection coils can be reduced in size. Thus, the deflection magnetic field can be effectively used, and the deflection sensitivity can be increased.

Further, in the ninth configuration of the present invention, since the deflecting yoke is provided with the octupole magnetic field generating coil driven by the DC power supply, the trilemma index relating to convergence can be improved, and good convergence over the entire screen can be achieved. Is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a deflection yoke according to a first embodiment of the present invention.

FIG. 2 is a view of the deflection yoke according to the first embodiment of the present invention viewed from a screen side.

FIG. 3 is an explanatory diagram illustrating a difference in operation depending on the position of a deflection yoke according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a leakage magnetic flux of the deflection yoke according to the first embodiment of the present invention.

FIG. 5 is a configuration diagram showing a deflection yoke according to a second embodiment of the present invention.

FIG. 6 is a view of a deflection yoke according to a second embodiment of the present invention as viewed from a screen side.

FIG. 7 is a view of a deflection yoke according to a third embodiment of the present invention as viewed from a screen side.

FIG. 8 is an explanatory diagram showing a winding structure of a deflection yoke according to a fourth embodiment of the present invention.

FIG. 9 is a view of a deflection yoke according to a fourth embodiment of the present invention as viewed from a screen side.

FIG. 10 is an explanatory diagram illustrating a winding method according to a fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a winding structure of a deflection yoke according to a fifth embodiment of the present invention.

FIG. 12 is a view of a deflection yoke according to a fifth embodiment of the present invention as viewed from a screen side.

FIG. 13 is a configuration diagram showing a deflection yoke according to a sixth embodiment of the present invention.

FIG. 14 is an explanatory diagram showing a leakage magnetic flux eliminating coil according to a sixth embodiment of the present invention.

FIG. 15 is an explanatory diagram showing a magnetic field created by a leakage magnetic flux canceling coil and a magnetic field created by a core according to Embodiment 6 of the present invention.

FIG. 16 is an explanatory diagram showing contour lines of a magnetic field created by a leakage magnetic flux eliminating coil according to Embodiment 6 of the present invention.

FIG. 17 is an explanatory diagram showing a leakage magnetic flux elimination coil according to a seventh embodiment of the present invention.

FIG. 18 is a configuration diagram showing a deflection yoke according to an eighth embodiment of the present invention.

FIG. 19 is an explanatory diagram showing a neck portion of a deflection yoke according to a ninth embodiment of the present invention.

FIG. 20 is a view of a rib according to a ninth embodiment of the present invention as viewed from a neck direction.

FIG. 21 is a view of an insulating plate according to a ninth embodiment of the present invention viewed from a screen direction.

FIG. 22 is a diagram showing an eight-pole coil according to Embodiment 10 of the present invention.

FIG. 23 is an explanatory diagram showing forces acting on RGB beams according to the tenth embodiment of the present invention.

FIG. 24 is a configuration diagram showing a conventional deflection yoke.

[Explanation of symbols]

Reference Signs List 10 Magnetic body (core) constituting deflection yoke, 11 Screen-side winding frame of magnetic vertical deflection coil, 12 Vertical deflection coil, 13 Winding frame of horizontal deflection coil, 14 Horizontal deflection coil, 15 CRT 16 Horizontal deflection coil wound in the opposite direction around the tip of the deflection yoke, 17 Spacer between the core and the vertical deflection coil, 18 Rib for defining the position of the horizontal deflection coil, 19 Additional winding Wire, 20 area where additional windings are present, 21 area where folded parts are present, 22 area of negative polarity of magnetic charge induced in the core, 23 direction of magnetic field generated by the core, 24 area induced by the core Region of the positive polarity of the magnetic charge, 25 part of the horizontal deflection coil, 26 part of the horizontal deflection coil, 27 part of the horizontal deflection coil, 28 current flowing in the horizontal deflection current Direction of current, 29 direction of current flowing in horizontal deflection current, 30 winding frame of horizontal deflection coil, 31 winding frame of horizontal deflection coil, 32 part of horizontal deflection coil arranged at the center of deflection yoke 33, the position of the rib for forming the crossover portion, 34 the position of the rib for forming the crossover portion, 35 the coil for eliminating the leakage magnetic flux, 36 the magnetic field line generated by the deflection yoke, 38, contour lines of the magnetic field generated by the coil for eliminating magnetic flux leakage, 39 coils for eliminating magnetic flux leakage, 40 lines of magnetic force generated by the deflection yoke, 41 direction of current flowing through the coil for eliminating magnetic flux leakage, 42 core constituting the deflection yoke, 43 Winding frame of horizontal deflection coil, 44 Cross section of horizontal deflection coil, 45 Insulator to keep insulation between horizontal deflection coil and vertical deflection coil, 46 Vertical Rib structure part that forms the cross section of the directional coil, 47 Cross section of the vertical deflection coil, 48 Frame for insulating the vertical deflection coil from the core, 49 Winding of the 8-pole coil, 50 Magnetic field lines generated by the 8-pole coil , 51 R beam, 52 G beam, 53 B beam.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yutaka Ono 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation

Claims (9)

[Claims] In a deflection yoke of a self-convergence type color CRT having an in-line type electron gun, a folding portion is formed by folding a winding at a screen side transition portion of a horizontal deflection coil toward a neck side, and is provided at a neck portion of the horizontal deflection coil. A deflection yoke for a color CRT, wherein additional windings in the same winding direction are provided. 2. A deflection yoke of a self-convergence type color CRT having an in-line type electron gun, wherein a turn-up portion is formed by turning a winding of a horizontal cross-section of a horizontal deflection coil toward a neck, and provided at a center portion of the horizontal deflection coil. A deflection yoke for a color CRT, wherein additional windings in the same winding direction are provided. 3. The winding frame for locking the winding of the horizontal deflection coil turn-up portion, wherein the position of the rib for locking the winding advances axially toward the screen in accordance with the winding order. 3. A deflection yoke for a color CRT according to claim 1. 4. The deflection yoke of a color CRT according to claim 3, wherein the winding of the folded portion of the horizontal deflection coil is provided outside the core. 5. A magnetic flux leakage elimination coil provided outside the core on the deflection yoke screen side and having a structure in which a front end portion is bent toward the inside of the core front end portion. Color CRT deflection yoke. 6. A closed current loop is formed independently of the horizontal deflection coil, and a leakage magnetic flux elimination coil is provided at a screen-side tip of the core at a position intersecting with the leakage magnetic flux. A color CRT according to claim 1 or 2.
Deflection yoke. 7. A gap between the horizontal deflection coil and the core,
3. The deflection yoke of a color CRT according to claim 1, wherein the screen side is larger than the neck side. 8. The deflection yoke for a color CRT according to claim 1, wherein a recess for accommodating a rib portion of the vertical deflection coil winding frame is provided in the horizontal deflection coil winding frame. 9. The deflecting yoke is provided with an octupole magnetic field generating coil driven by a DC power supply.
Or a deflection yoke of the color CRT according to 2.