JPH0739163Y2 - Deflection yoke - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a deflection yoke of an in-line type color picture tube.

[Conventional technology]

In an in-line type color picture tube, it is known that a horizontal deflection magnetic field is a pincushion type magnetic field and a vertical deflection magnetic field is a barrel type magnetic field to achieve convergence-free (automatic concentration). In this case, from the relationship of matching the convergence of the corners, as shown in FIG. 8, both side beams 5R and
There is a limit to the method of adjusting the vertical misconvergence in the middle part where 5B does not match the center beam concentration point. As one of the methods, there is a method of emphasizing a predetermined order when the winding distribution of the vertical deflection coil is Fourier expanded, but if this is strengthened, the lateral misconvergence at the corner portion is deviated and it becomes difficult to be convergence-free.
In addition, as shown in FIG. 9, the S-shaped misconvergence of the corner portion shifts in the negative direction.

Further, in the case of a flat color cathode ray tube having a fluorescent screen, as shown in FIG. 10, the left and right pincushion distortion in the middle portion tends to be deteriorated.

[Problems to be solved by the invention]

This invention intends to simultaneously improve both the vertical misconvergence of the intermediate portion and the left and right pincushion distortions of the intermediate portion, which occur when the convergence is free. In addition, this invention has a low-cost structure in which four magnets are provided.

A structure in which four magnets are used as auxiliary deflecting means is disclosed in, for example, Japanese Patent Publication No. Sho 58-43857, and the one disclosed in this publication has a polarity for correcting left and right pincushion distortion, and x A magnet is arranged on the shaft, and it is impossible to improve the vertical misconvergence of the intermediate portion and the pincushion distortion of the left and right portions of the intermediate portion, which is the object of the present invention.

[Means for solving problems]

This invention is a deflection yoke in which a horizontal deflection coil is formed in a saddle shape, and a vertical deflection coil is toroidally wound around a core. The horizontal direction of the phosphor screen is the x-axis, and the vertical direction of the phosphor screen is the y-axis. In the deflection yoke of the in-line type color picture tube having the tube axis direction as the z axis, it is provided on the x axis on the side close to the panel of the color picture tube.
A pair of magnets 3A and 3B having polarities in the direction of increasing the left and right pincushion distortion, and provided on the y-axis near the panel of the color picture tube,
A deflection yoke comprising: a pair of magnets 4A, 4B having polarities in a direction of reducing upper and lower pincushion distortions.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 1 shows an example of a deflection yoke to which the present invention can be applied. FIG. 1 shows the entire deflection yoke, 1A and 1B are horizontal deflection coils, and 2A and 2B are vertical deflection coils. As shown in FIG. 2, the horizontal deflection coils 1A and 1B are formed in a saddle shape, and the vertical deflection coils 2A and 2B are wound around the core 10 in a toroidal shape. 1A 'and 1B' are horizontal deflection coils
These are bend parts of 1A and 1B. As shown in FIG. 3, a deflection yoke is attached so as to cover the funnel portion of the in-line type color picture tube 12.

In this case, the horizontal deflection coils 1A and 1B are arranged inside the separator 11, which is a plastic molded product, and the toroidally wound vertical deflection coils 2A and 2B are arranged outside thereof. In addition,
In FIG. 3, reference numeral 13 denotes a color picture tube panel.

Then, the horizontal deflection magnetic fields by the horizontal deflection coils 1A and 1B are made into a pincushion type, and the vertical deflection magnetic fields by the vertical deflection coils 2A and 2B are made into a barrel type, thereby achieving convergence-free.

In the deflection yoke of the above-mentioned in-line type color picture tube, as shown in FIG. 4, a pair of magnets 3A and 3B are arranged so as to be positioned on the x-axis in the horizontal direction, and the y-axis in the vertical direction is arranged.
A pair of magnets 4A and 4B are arranged so as to be located on the axis. The positions of these magnets 3A, 3B, 4A, 4B on the z-axis may be on the side of the horizontal deflection coils 1A, 1B near the panel 13. For example, the bend portions 1A ′, 1 of the horizontal deflection coils 1A, 1B
A magnet 3 is attached to the front end of the separator 11 that stores B '.
A, 3B, 4A, 4B are incorporated. As another attachment method, the magnets 3A, 3B, 4A, 4B may be adhered to the front end portion of the separator 11.

FIG. 5 shows the polarities of the magnets 3A, 3B, 4A and 4B described above and the electromagnetic force received by the electron beam due to the magnetic fields generated by these magnets. The electron beam is emitted from the electron gun and reaches the phosphor screen provided on the panel side. This electron beam is considered to be a current in the direction opposite to the direction of travel of the beam (in FIG. 5, the direction from the front side to the back side of the drawing sheet). On the other hand, the direction of the lines of magnetic force generated by each magnet is
As shown in FIG. 5, since the direction is from the N pole to the S pole, the electron beam receives the electromagnetic force in the direction shown by the arrow in FIG. The direction of this electromagnetic force received is the same for the three beams of red, green and blue.

More specifically, the magnet located on the x-axis
The polarities of 3A and 3B are supposed to increase the left and right pincushion distortion. The magnetic fields of the magnets 3A and 3B are the largest on both the left and right sides of the phosphor screen, and become smaller toward the center.

Therefore, by selecting the magnetic force by the magnets 3A and 3B, as shown by the broken line in FIG. 10, the left and right pincushion distortions are aggravated on both the left and right sides of the phosphor screen, and the left and right pincushion distortions are reduced in the middle part. , 3B can be equivalent to the case without. That is,
Almost the left and right pincushion distortions in the middle part remain, and the left and right pincushion distortions in both the left and right sides are exacerbated, so that the left and right pincushion distortions in the middle part can be relatively improved. In other words, about the same amount of left and right pincushion distortion is generated over the entire phosphor screen. As a result, a configuration using a pincushion transformer,
Alternatively, the pincushion distortion can be corrected by a conventional left and right pincushion distortion correction circuit having a structure for modulating the power supply voltage of the horizontal deflection circuit. As described above, the embodiment of the present invention can correct the left and right pincushion distortion in the middle portion.

Next, correction of the intermediate vertical convergence (see FIG. 8) by the magnets 3A and 3B will be described. As shown in FIG. 5, in the upper part on the left side of the phosphor screen, an electromagnetic force for moving the beam diagonally upward to the right is generated by the magnet 3B,
At the lower left side of the phosphor screen, an electromagnetic force that moves the beam diagonally downward right is generated. The electromagnetic force generated by the magnet 3B also acts on the side beam 5B, the center beam 5G and the side beam 5R, as shown in FIG. However, since the distance between the magnet 3B and the beams 5G and 5R is larger than that of the side beams 5B, the force acting on the beams 5G and 5R is smaller.

On the other hand, on the upper right side of the fluorescent screen, the magnet 3A
An electromagnetic force is generated to move the beam, especially the side beam 5R having a short distance, to the upper left. The force exerted by the magnet 3A on the center beam 5G and the side beam 5B is smaller than that on the side beam 5R. Further, in the lower part on the right side of the phosphor screen, an electromagnetic force that causes the beam, particularly the side beam 5R having a short distance, to move diagonally downward left is generated.

As described above, the magnet 3A provided on the x-axis,
By 3B, the vertical misconvergence in the middle portion as shown in FIG. 8 is corrected.

Next, the correction of the S-shaped misconvergence of the corner portion as shown in FIG. 9 performed by the magnets 4A and 4B will be described. FIG. 7 shows the electron beam 5R on the fluorescent screen,
5G and 5B indicate the force received by the magnetic force of the magnet. 3A ', 3B', 4A, 4B 'are magnets 3A,
The magnetic field lines generated by 3B, 4A, and 4B are shown.

As shown in FIG. 5, the polarities of the magnets 4A and 4B located on the y-axis are set so as to reduce the vertical pincushion distortion. More specifically, as shown in FIG. 7, on the upper left side of the phosphor screen provided with the magnet 4A, an electromagnetic force that moves the beams 5B, 5G, and 5R diagonally upward is generated, and on the upper right side thereof, , Electromagnetic force is generated to move the beams 5B, 5G, 5R diagonally upward to the left. In this case, on the upper left side, the side beam 5R close to the magnet 4A receives a larger force than the other beams. On the other hand, on the upper right side, the side beam 5B closer to the magnet 4A receives a larger force than the other beams. This electromagnetic force becomes smaller toward the left and right end portions of the fluorescent screen and the central portion.

Thus, the side beam 5R receives the strongest force in the left half of the fluorescent screen by the magnetic field lines 4A ′ of the magnet 4A,
In the right half, the side beam 5B receives the strongest force,
At the center, the three beams are subjected to approximately equal forces. Therefore, the S-shaped misconvergence at the corner on the upper side of the phosphor screen in FIG. 5 is improved.

On the other hand, on the lower left side of the fluorescent screen where the magnet 4B is provided,
An electromagnetic force that moves the beams 5B, 5G, and 5R diagonally downward right is generated, and an electromagnetic force that moves the beams 5B, 5G, and 5R diagonally downward left is generated on the lower right side thereof. In this case, on the lower left side, the side beam 5R close to the magnet 4B receives a larger force than the other beams. On the other hand, on the lower right side, the side beam 5B closer to the magnet 4B receives a larger force than the other beams. This electromagnetic force becomes smaller toward the left and right end portions of the fluorescent screen and the central portion.

Thus, the side beam 5R receives the strongest force in the left half of the fluorescent screen by the magnetic field lines 4B ′ of the magnet 4B,
In the right half of the phosphor screen, the side beam 5B receives the strongest force, and in the center, the three beams receive substantially equal forces.
Therefore, the S-shaped misconvergence at the lower corner in FIG. 5 is improved.

In addition, in FIG. 7, the magnetic field lines 3 generated by the magnets 3A and 3B.
A ', 3B' and the direction and strength of the force that the electron beam receives are entered. Also from FIG. 7, as described above,
It can be seen that the vertical misconvergence in the middle part can be corrected by the magnets 3A and 3B.

[Effect of device]

According to this invention, both of the vertical misconvergence in the middle portion and the left and right pincushion distortions in the middle portion can be simultaneously improved with a low-cost structure in which four magnets are provided.

[Brief description of drawings]

1 is a perspective view of an example of a deflection yoke to which the present invention can be applied, FIG. 2 is a perspective view showing a horizontal deflection coil and a vertical deflection coil, and FIG. 3 is a deflection yoke attached to a color picture tube. FIG. 4 is a perspective view showing a state, FIG. 4 is a front view of an embodiment of the present invention, and FIG. 5 is a schematic diagram showing a direction of a force acting on an electron beam by a magnet in an embodiment of the present invention. 6 is a schematic diagram for explaining the correction of the intermediate vertical misconvergence according to one embodiment of the present invention, and FIG. 7 is the intermediate vertical misconvergence and the corner S-shaped misconvergence according to one embodiment of the present invention. 8 is a schematic diagram showing the vertical misconvergence of the intermediate portion, and FIG. 9 is a schematic diagram showing the S-shaped misconvergence of the corner portion.
The figure is a schematic diagram showing the left and right pincushion distortion in the middle portion. Description of main symbols in the drawings 1A, 1B: horizontal deflection coil, 2A, 2B: vertical deflection coil, 3A,
3B, 4A, 4B: Magnet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-33623 (JP, A) JP-A-58-220342 (JP, A) Actual development Sho-54-96532 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A deflection yoke in which a horizontal deflection coil is formed into a saddle shape and a vertical deflection coil is toroidally wound around a core, wherein the horizontal direction of the fluorescent screen is the x-axis and the vertical direction of the fluorescent screen is the y-axis. In the deflection yoke of the in-line type color picture tube having the z-axis in the tube axis direction, the polarity of the polarity in the direction of increasing the left and right pincushion distortion, which is provided on the x-axis near the panel of the color picture tube, A deflection yoke comprising: a pair of magnets; and a pair of magnets provided on the y-axis near the panel of the color picture tube and having a polarity in a direction to reduce vertical pincushion distortion.