JP2001243899A - Color picture tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a vertical pincushion distortion and a vertical inner pincushion distortion with low cost, simple and easy way. SOLUTION: A magnet 31 is provided which generates a magnetic field of homopolarity with a magnetic field generated by a vertical deflection coil 13 when deflected on the upper side, at the side of a phosphor screen of the deflection coil on upper side than a horizontal axis. A magnet 32 generating a magnetic field of homopolarity with a magnetic field generated by the vertical deflection coil 13 when deflected on the lower side fluorescent the is provided at the lower side than the horizontal axis. A magnet 33 generating a magnetic field of antipolarity with a magnetic field generated by the vertical deflection coil 31 when deflected on the upper side is provided nearer to side of the phosphor screen than the magnets 31, 32 on the upper side than the horizontal axis. A magnet 34 is provided generating a magnetic field of antipolarity with a magnetic field generated by the vertical deflection coil 13 when deflected on the lower side, at lower side than the horizontal axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube device used for a monitor or a television receiver.

[0002]

2. Description of the Related Art Raster distortion is one of the important image quality factors of a color picture tube. Conventionally, the upper and lower pincushion distortion and the right and left pincushion distortion in the peripheral portion are caused by the magnetic field of the deflection yoke and the color picture tube device. Is corrected by the correction circuit. However, even if these distortions in the upper, lower, left, and right peripheral portions are optimized, pincushion distortion may remain in the middle portion of the vertical line or the middle portion of the horizontal line. These are called "left and right inner pincushion distortion" (FIG. 6) and "upper and lower inner pincushion distortion" (FIG. 7), respectively. “Left and right inner pincushion distortion” is also called “vertical line inner pincushion distortion”, and “upper and lower inner pincushion distortion” is also called “horizontal line inner pincushion distortion”.

Generally, the displacement X (t) of the position of a luminescent spot on a flat screen is proportional to tan θ, where θ is the deflection angle. Therefore, a non-linear distortion called "S-shaped distortion" occurs, in which the amount of displacement in the horizontal direction increases as approaching the peripheral portion of the phosphor screen surface in the horizontal direction. This S-shaped distortion is corrected by adding an S-shaped distortion correction circuit. S
The required correction amount of the character distortion is inversely proportional to the vertical distance from the center of deflection to each point on the phosphor screen. As shown in FIG. 8, since the distance from the center of deflection is longer at the upper and lower parts of the raster of the color picture tube, that is, at the peripheral part 18 in the vertical direction of the phosphor screen surface, than at the intermediate part 17 (range indicated by oblique lines), The required correction amount of distortion is smaller than that of the middle part.

However, the S-shaped distortion correction circuit of the conventional color picture tube apparatus optimizes the S-shaped distortion correction at the vertical intermediate portion of the phosphor screen surface, but the S-shaped distortion correction circuit of the conventional color picture tube device has a vertical intermediate portion of the phosphor screen surface. Since the difference in the required correction amount from the peripheral portion is not taken into account, the S-shaped distortion is overcorrected in the peripheral portion, and there is a problem that left and right inner pincushion distortions occur. In particular, with the flattening of the front panel of the color picture tube and the increase in the deflection angle, the left and right inner pincushion distortion has become remarkable.

To solve such a problem, Japanese Patent Application Laid-Open No. 9-149
In the invention described in Japanese Patent No. 283, the horizontal deflection current is supplied to the saturable reactor, and the current is modulated by the vertical deflection current.
The overall inductance of the horizontal deflecting part during deflection to the upper and lower parts of the raster, that is, to the vertical peripheral portion, becomes smaller when deflecting to the horizontal peripheral portion (ie, when deflecting to the diagonal corner portion). By adopting the configuration, the distortion of the left and right inner pin cushions was removed.

[0006]

With the recent flattening of the front panel of the color picture tube and an increase in the deflection angle, the horizontal left and right sides of the raster are similar to those in the vertical direction of the raster. Between the section and the middle section in the horizontal direction
A difference in the amount of character distortion correction occurs, and as a result, the problem of upper and lower inner pincushion distortions in addition to left and right inner pincushion distortions has become apparent. Japanese Unexamined Patent Application Publication No. 9-1492
The conventional inner pincushion distortion correction circuit described in Japanese Patent No. 83 is an effective means for correcting left and right inner pincushion distortions, but cannot correct upper and lower inner pincushion distortions. Therefore, in the related art, the vertical tilt of the deflection yoke in the vertical direction only balances the distortion in the vertical direction.

In addition, JP-A-6-283115,
In Japanese Unexamined Utility Model Publication No. 63-80756, magnets are arranged at the four corners of the deflection yoke to correct vertical barrel distortion in the middle part in the vertical direction. However, in this method, when correcting raster distortion, the middle part in the vertical direction is corrected. The convergence of the horizontal line between the red and blue beams is worsened, and the man-hours for mounting the magnet increase.
There was a problem that workability deteriorated.

Accordingly, in the present invention, in the color picture tube device, the upper and lower inner pincushion distortions are also corrected while correcting the upper and lower pincushion distortions, and the number of magnets to be attached may be two for each of the upper and lower sides. Therefore, it is an object of the present invention to provide means capable of reducing material costs, reducing man-hours, and improving workability.

[0009]

According to the present invention, there is provided a color picture tube apparatus comprising: a glass bulb having a phosphor screen surface on an inner surface thereof; and an in-line disposed in the glass bulb for irradiating the phosphor screen surface with an electron beam. In a color picture tube device provided with an electron gun and a deflection device having a horizontal deflection coil and a vertical deflection coil disposed outside the glass bulb, a vertical deflection coil is provided above a horizontal axis of the deflection device when the upper deflection is performed. A first magnetic field generator for generating a magnetic field having the same polarity as the magnetic field generated by the magnetic field generating means, and a magnetic field having the same polarity as the magnetic field generated by the vertical deflection coil at the time of downward deflection is provided below the horizontal axis of the deflecting device. A third magnetic field generator for generating a magnetic field having a polarity opposite to that of the magnetic field generated by the vertical deflection coil at the time of upward deflection above the horizontal axis of the deflection device; A fourth magnetic field generator for generating a magnetic field having a polarity opposite to that of the magnetic field generated by the vertical deflection coil at the time of lower deflection, below the horizontal axis of the deflecting device; The second magnetic field generator is disposed closer to the phosphor screen surface than the peak position of the deflection magnetic field intensity in the tube axis direction of the horizontal deflection coil and the vertical deflection coil, and the third and fourth magnetic field generators are provided. Are arranged at the same position as the positions of the first and second magnetic field generators in the tube axis direction or on the side of the phosphor screen surface side.

According to this structure, the upper and lower inner pincushion distortion in the middle portion in the vertical direction of the phosphor screen is corrected by the magnetic field having the same polarity as the magnetic field of the vertical deflection coil by the first and second magnetic field generators. Overcorrection of vertical pincushion distortion in the vertical peripheral portion, and only overcorrected vertical peripheral distortion caused by a magnetic field of the opposite polarity to the magnetic field of the vertical deflection coil by the third and fourth magnetic field generators. By correcting again, both the upper and lower pincushion distortion of the peripheral portion and the upper and lower inner pincushion distortion of the intermediate portion can be corrected.

[0011] In the above configuration, the third and the fourth.
The magnetic field strength of the first magnetic field generator is smaller than the magnetic field strength of the first and second magnetic field generators, and the third and fourth magnetic field generators in the vertical axis direction are the first and second magnetic field generators.
It is preferable that the magnetic field generator is disposed closer to the glass bulb than the magnetic field generator.

According to this preferred configuration, the electron beam deflected to the peripheral portion in the vertical direction and the electron beam deflected to the intermediate portion in the vertical direction by the magnetic field in the attenuation region of the first and second magnetic field generators are substantially formed. A force in the same correction direction can be applied, and a force in the opposite direction to the correction direction is applied only to the electron beam deflected to the peripheral portion in the vertical direction by the magnetic fields of the third and fourth magnetic field generators. Therefore, the upper and lower inner pincushion distortion can be corrected very effectively.

Further, in the color picture tube device of the present invention, it is preferable that the first to fourth magnetic field generators are constituted by magnets.

According to this preferred configuration, the size, shape, magnetic characteristics, etc. of the magnets forming the first and second magnetic field generators and the magnets forming the third and fourth magnetic field generators are appropriately selected. By doing so, it is possible to adjust the correction magnetic field acting on each electron beam deflected to the peripheral portion and the intermediate portion in the vertical direction of the phosphor screen surface, and to easily and inexpensively reduce the upper and lower pincushion of the peripheral portion. It is possible to correct both the distortion and the distortion of the upper and lower inner pin cushions in the middle part.

[0015]

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

The color picture tube device of the present invention comprises a color picture tube and a deflection device. As shown in FIG. 2, a color picture tube device according to the present invention comprises a glass bulb 3 having a phosphor screen surface 2 which emits blue, green and red light on an inner surface of a front panel 1.
And a shadow mask 4 disposed opposite to the phosphor screen surface 2 and a neck portion 5 of the glass bulb 3,
An in-line electron gun 7 for irradiating the phosphor screen surface 2 with an electron beam 6 and a deflecting device 9 mounted outside the funnel portion 8 and the neck portion 5 of the glass bulb 3. A bipolar magnet to adjust the purity and static convergence on the outside,
A convergence unit 10 having a quadrupole magnet and a hexapole magnet is added.

For convenience of the following description, a three-dimensional orthogonal coordinate system is set in which the horizontal axis passing through the pipe axis is the X axis, the vertical axis passing through the pipe axis (vertical direction) is the Y axis, and the pipe axis is the Z axis. I do.

FIG. 1 shows the deflecting device 9 viewed from above (N side), and FIG. 12 shows the deflecting device 9 similarly viewed from the side (E or W side).
FIG. 3 is a view of the deflecting device 9 as viewed from the phosphor screen surface side. The deflection device 9 incorporates a pair of horizontal deflection coils 11 for generating a magnetic field having pincushion distortion as a whole and a pair of vertical deflection coils 13 via a resin frame 12 for insulation and support. Has a ferrite core 14 incorporated therein. Further, a magnet 31 serving as a first magnetic field generator and a magnet 32 serving as a second magnetic field generator are provided at substantially vertically symmetric positions on the outer peripheral portion of the opening of the ferrite core 14 on the phosphor screen surface side. Have been. Further, a magnet 33 serving as a third magnetic field generator and a magnet 34 serving as a fourth magnetic field generator are located at substantially vertically symmetric positions on the outer peripheral portion of the opening of the vertical deflection coil 13 on the phosphor screen surface side. Each is provided. These magnets 31 to 34 are all disposed on the phosphor screen surface side of the ferrite core 14 and on the phosphor screen surface side of the peak position of the deflection magnetic field intensity in the tube axis direction. The peak position of the deflecting magnetic field strength is determined by superposition of magnetic fields from three portions (an electron gun-side arc portion, a cone portion, and a screen-side arc portion) constituting the deflecting coil. It is well known that it appears near an inflection point from a portion substantially parallel to the tube axis to a curved surface portion (a portion expanding in accordance with the funnel).

FIG. 4 is a diagram showing the magnetic field when the electron beam is deflected to the upper side of the phosphor screen as viewed from a direction parallel to the tube axis. The polarity of the magnetic field generated by the first magnet 31 is the magnetic field (shown by a broken line) generated by a vertical deflection coil (not shown).
It has the same polarity as. On the other hand, the polarity of the magnetic field generated by the third magnet 33 is opposite to this. The second magnet 32 is arranged to generate a magnetic field in a direction opposite to that of the first magnet 31, and the fourth magnet 34 generates a magnetic field in a direction opposite to that of the third magnet 33. Placed in

FIG. 5 is a diagram showing how the upper and lower inner pincushion distortions are corrected by the present invention. The electron beam emitted from the in-line electron gun 7 is supplied to the deflection device 9
Is deflected over the entire area of the phosphor screen surface 2 by the magnetic field produced by the magnetic field. Go through orbit. When a magnetic field having a polarity as shown in FIG. 4 is generated from each of the magnets 31 and 33, the magnetic field is generated from the first magnet 31 in the region I on the electron gun side because the difference between the two orbits A and B is small. The magnetic field acts not only on the electron beam A deflected to the peripheral part but also on the electron beam B deflected to the middle part, and all the electron beams receive a force 51 indicated by a thick arrow in the same direction as the deflection direction. In contrast, the area II on the phosphor screen surface side
Since the difference between the trajectories of A and B is large and the effect of the magnetic field generated by the third magnet 33 on the electron beam passing through the trajectory of B is extremely small, only the electron beam passing through the trajectory of A is in the opposite direction to the deflection direction. The force 52 indicated by the thick arrow is received.

FIGS. 9 and 10 show how the upper and lower inner pincushion distortions and the upper and lower pincushion distortions are corrected stepwise by the present invention. In FIG. 9, when the upper and lower inner pincushion distortion before the correction indicated by the broken line is optimized and corrected by the action of the force 51 as shown by the solid line, the upper and lower pincushion distortions are overcorrected in the peripheral portion. As a result, the peripheral portion is inversely corrected again, and as a result, the raster distortion is in an appropriate state as shown in FIG.
In this manner, the upper and lower inner pincushion distortions can be corrected while optimizing the upper and lower pincushion distortions.

The case where the electron beam is deflected to the upper side of the phosphor screen surface has been described above. When the electron beam is deflected to the lower side, the direction of the vertical deflection magnetic field (broken line) shown in FIG. The second magnet 32 and the fourth magnet 34, which are magnetic field generators, are connected to the first and third magnets 31, 3 described above.
3 works in the same way.

Next, a description will be given of an experimental example in which the effect of the present invention was confirmed for a display color picture tube device having a diagonal size of 46 cm (19 inches). In the experiment, the size of the magnets 31 and 32 was 5 [mm] × 5.
[Mm] × 15 [mm] and a magnetic field strength of 0.05 [T] are used, and the size of the magnets 33 and 34 is 2 [mm] ×
5 [mm] x 10 [mm] and magnetic field strength of 0.02 [T]
Was used. The magnets 31 and 32 are positioned at 28 [mm] from the peak position of the vertical deflection magnetic field strength to the phosphor screen surface side.
, The magnets 33 and 34 were similarly set at a position of 48 [mm]. Each magnet was installed with its longitudinal direction parallel to the X-axis direction.

When the raster distortion is optimized only by the deflection magnetic field (comparative example), the upper and lower pincushion distortion is 0.1 mm and the upper and lower inner pincushion distortion is 0.9 mm. The upper and lower inner pincushion distortion was conspicuous. In contrast, the magnets 31 to 3 of the present invention
4, when the distortion was optimized, the upper and lower pincushion distortions were 0.1 [mm] and the upper and lower inner pincushion distortions were 0.4 [mm]. While maintaining the level, the distortion of the upper and lower inner pin cushion was improved.

The magnetic field strength, size, and mounting position of the magnet to be used are determined as follows while taking into consideration the overall balance of the raster distortion.

With respect to the magnetic field intensity, basically, a magnetic field intensity sufficient to correct the upper and lower inner pincushion distortion to almost zero is applied to the first and second magnets 31 and 32, and the overcorrected peripheral portion The upper and lower pincushion distortion is reduced to 0.
A magnetic field strength that can be re-corrected may be applied to the magnets 33 and 34 to about 5 mm or less.

Regarding the size, if the length of the magnet in the longitudinal direction is too short, an unnecessary undulation component is generated in the raster distortion, and if it is too long, it becomes difficult to correct only a desired portion. It is necessary to select the size while watching the distortion.

Further, regarding the mounting position in the tube axis direction, even if a magnet is disposed outside the ferrite core, a substantial correction effect cannot be obtained, so that the magnets 31 and 32 are provided on the phosphor screen surface more than the ferrite core. It is preferable that the magnets 33 and 34 are arranged at the end of the deflecting device on the phosphor screen surface side in the region on the side and as close to the electron gun as possible.

However, as described above, it is necessary to make adjustments so as to obtain an optimum combination each time while checking the balance of the entire raster distortion.

FIG. 11 is a diagram showing the distribution of the magnetic field strength of the magnet used in the present invention in the vertical axis direction. A curve a indicates a magnet having a large magnetic field strength, and a curve b indicates a magnet having a small magnetic field strength. In any of the magnets, the magnetic field intensity sharply decreases in a region near the magnet, and the change in the magnetic field intensity gradually decreases as the distance from the magnet increases. For the first and second magnets 31 and 32, those having a large magnetic field strength are used away from the funnel, and the third and fourth magnets 33 and 32 are used.
It is more effective to use a material having a small magnetic field strength near the funnel. This is because, in the region I (see FIG. 5), the electron beam passing through both the trajectories A and B is desired to be pulled up in the peripheral direction with the same strength as much as possible. This is because it is more effective to use the region (1) in which the change in the magnetic field strength distribution is attenuated to some extent. Conversely, region II (see Fig. 5)
In this case, it is desired to apply the re-correction force only to the electron beam passing through the orbit of A. In this case, it is better to use the region (2) where the change in the magnetic field strength distribution in the direction of the vertical axis of the magnet changes sharply. This is because it is effective.

As shown in FIG. 13, the mounting positions of the first and second magnets 31a and 32a in the tube axis direction are the same as the mounting positions of the third and fourth magnets 33a and 34a in the same direction. Even in some cases, the same effect can be obtained if the magnets 33a, 34a have a smaller magnetic field strength than the magnets 31a, 32a, and if the magnets 33a, 34a are mounted closer to the funnel than the magnets 31a, 32a in the vertical axis direction. Further, in this case, when the upper and lower raster distortions before correction have a swell component as shown in FIG. 14, the first and second magnets 31a and 32a as shown in FIG.
Is preferably longer than the lengths of the third and fourth magnets 33a and 34a. As a result, the entire upper and lower raster distortions are corrected by the first and second magnets 31a and 32a as shown in FIG. 16, and the central convex portion a is reversely corrected by the third and fourth magnets 33a and 34a. The swell component can be removed as shown in FIG.

In the above embodiment, the magnets 31 to 34 (31a to 34a) are used as the first to fourth magnetic field generators, but an electromagnet using a coil may be used.

[0033]

As described above, according to the present invention,
The upper and lower inner pincushion distortions can be corrected while optimizing the upper and lower pincushion distortions, and a high-quality color picture tube device can be provided by simple and low-cost means.

[Brief description of the drawings]

FIG. 1 is a view of a deflection device of the present invention as viewed from above.

FIG. 2 is a cross-sectional view of the color picture tube device of the present invention.

FIG. 3 is a view of the deflecting device as viewed from the phosphor screen surface side.

FIG. 4 is a diagram showing the relationship between the direction of a magnetic field generated by a magnetic field generator (correction magnet) of the present invention and the direction of a vertical deflection magnetic field.

FIG. 5 is a diagram showing a state in which upper and lower inner pincushion distortions are corrected by the magnetic field generator (correction magnet) of the present invention.

FIG. 6 is an explanatory diagram of left and right inner pin cushion distortions.

FIG. 7 is an explanatory view of upper and lower inner pin cushion distortions.

FIG. 8 is an explanatory view of a vertical peripheral portion and an intermediate portion region of a phosphor screen surface.

FIG. 9 is a diagram showing a state in which upper and lower inner pincushion distortions are corrected by the present invention.

FIG. 10 is a diagram showing a state in which upper and lower pincushion distortions are further corrected by the present invention.

FIG. 11 is a diagram showing the distribution of the magnetic field strength of the magnetic field generator (correction magnet) used in the present invention in the vertical axis direction.

FIG. 12 is a side view of the deflection device of the present invention.

FIG. 13 is a side view of the deflection device of the present invention in which the respective magnetic field generators (correction magnets) are mounted at the same position in the tube axis direction.

FIG. 14 is a diagram showing a state where upper and lower peripheral portions of a raster have a swell component;

FIG. 15 is a view of a deflection device of the present invention using two types of magnets having different lengths as magnetic field generators as viewed from the phosphor screen surface side.

FIG. 16 is a diagram showing a state in which the upper and lower inner pincushion distortions in FIG. 14 are corrected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front panel 2 Phosphor screen surface 3 Glass bulb 4 Shadow mask 5 Neck part 6 Electron beam 7 Electron gun 8 Funnel part 9 Deflection device 11 Horizontal deflection coil 12 Resin frame 13 Vertical deflection coil 14 Ferrite core 31-34, 31a-34a Magnet (magnetic field generator)

Claims (3)

[Claims] 1. A glass bulb having a phosphor screen surface on an inner surface, an in-line electron gun arranged in the glass bulb for irradiating an electron beam on the phosphor screen surface, and a horizontal bulb arranged outside the glass bulb. A color picture tube device comprising a deflection coil and a deflection device having a vertical deflection coil, wherein a magnetic field having the same polarity as a magnetic field generated by the vertical deflection coil at the time of upward deflection is provided above a horizontal axis of the deflection device. A second magnetic field generator that generates a magnetic field having the same polarity as the magnetic field generated by the vertical deflection coil at the time of downward deflection below the horizontal axis of the deflection device; A third magnetic field generator which generates a magnetic field having a polarity opposite to that of the magnetic field generated by the vertical deflection coil during upward deflection is provided above the horizontal axis of the deflecting device. On the lower side, a fourth magnetic field generator that generates a magnetic field having a polarity opposite to the magnetic field generated by the vertical deflection coil at the time of lower deflection is provided, and the first and second magnetic field generators include the horizontal deflection coil and The third and fourth magnetic field generators are arranged closer to the phosphor screen surface than the peak position of the deflection magnetic field intensity in the tube axis direction of the vertical deflection coil, and the third and fourth magnetic field generators are the same as those of the first and second magnetic field generators. A color picture tube device, wherein the color picture tube device is arranged at the same position as the position in the tube axis direction or on the side of the phosphor screen surface. 2. A magnetic field intensity of said third and fourth magnetic field generators is smaller than a magnetic field intensity of said first and second magnetic field generators, and said third and fourth magnetic field generators are arranged in a vertical axis direction.
2. The magnetic field generator according to claim 1, wherein the magnetic field generator is located closer to the glass bulb than the first and second magnetic field generators.
3. A color picture tube device according to claim 1. 3. The color picture tube device according to claim 1, wherein the first to fourth magnetic field generators are magnets.