JPH0563182U - Dynamic convergence correction device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a correction device that improves image quality by compensating for overcorrection in the middle part of the screen when correcting misconvergence in the peripheral part of the screen of a cathode ray tube. A vertical auxiliary coil connected in series to a vertical deflection coil is divided into first and second vertical auxiliary coils so as to generate magnetic fields having opposite polarities, and a slice portion is connected in parallel to the second vertical auxiliary coil. Then, the vertical deflection current above and below a certain level is sliced, and a vertical deflection current of a sawtooth wave similar to that of the vertical deflection coil flows through the first vertical auxiliary coil to correct misconvergence in the peripheral portion of the screen, and the second vertical A sliced vertical deflection current flows in the deflection coil to compensate for overcorrection in the middle of the screen when correcting misconvergence in the peripheral area of the screen, and correct the misconvergence of the entire screen to improve image quality. ..

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dynamic-convergence compensator that improves the deterioration of image quality in the middle part of the screen when compensating for misconvergence occurring in the peripheral part of the screen of a cathode ray tube.

[0002]

[Prior Art]

 Generally, cathode ray tubes used for television receivers and monitors are such that due to errors in assembling the electron gun and enclosing the electron gun, the three electron beams emitted from the electron gun simultaneously reach one point in the same hole of the shadow mask. Misconvergence occurs in which the three colors appearing on the screen without being concentrated are separated from each other, resulting in poor image quality such as uneven color.

Methods for correcting such misconvergence are disclosed in JP-A-59-111491, JP-A-60-41738 and "A 17 in, Full Square, Super high-Resolution CRT" (Japan Display). 1986, 222p and below).

For the convergence, three electron beams are concentrated in the central part of the screen by adjusting the magnetic field strength and polarity of the permanent magnet to adjust the orbit of the electron beam in the central part of the screen. In addition to the static convergence described above, the deflection yoke is provided with a correction device for horizontal and vertical deviations, and three electron beams are synchronized with vertical and horizontal deflection according to the degree of misconvergence before being deflected by the deflection magnetic field. Convergence There is dynamic convergence in which the current flowing through the coil is adjusted so that the three electron beams are concentrated on the shadow mask surface.

However, when the dynamic convergence adjustment is performed so that the three electron beams are concentrated in the peripheral area of the screen, the convergence is overcorrected in the intermediate area between the central area and the peripheral area of the screen, and the image quality is reduced. There was a problem of a decline.

FIG. 1 is a circuit diagram showing a deflection yoke in which a conventional correction device is configured.

As shown in FIG. 1, the horizontal deflection coils 1 and 2 are respectively connected in series to two horizontal auxiliary coils (1a, 1b) (2a, 2b) that generate magnetic fields of opposite polarities. Permanent magnets 3 and 4 for varying the inductance of the horizontal auxiliary coils (1a, 1b) (2a, 2b) are provided, and the vertical auxiliary coils 7 are connected to the vertical deflection coils 5 and 6.

Further, as shown in FIG. 2, the vertical auxiliary coil 7 is wound around a vertical core 7a, and horizontal cores (1c, 1d) (2c, 2d) are provided on both left and right sides of the vertical core 7a in the figure. , Horizontal auxiliary coils (1a, 1b) (2a, 2b) are wound around the horizontal cores (1c, 1d) (2c, 2d) to generate magnetic fields of opposite polarities, and the horizontal cores (1c, 1d) Permanent magnets 3 and 4 are provided outside (2c, 2d).

In the correction device having the above-mentioned configuration, when the vertical deflection current flows through the vertical auxiliary coil 7, the vertical auxiliary coil 7 and the horizontal auxiliary coils (1a, 1b) (2a, 2b) are magnetically connected, A difference occurs in the inductance between the horizontal auxiliary coils (1a, 1b) (2a, 2b) provided on the upper side and the lower side in the figure, and the difference in the inductance causes a difference in the current flowing through the horizontal deflection coils 1 and 2. As shown in FIG. 3 (A), the three electron beams are not concentrated in the peripheral portion of the screen, and a corner vertical (CV) is generated.

Such misconvergence is dynamically corrected as shown in FIG. 3B so that the three electron beams are concentrated and coincide with each other on the shadow mask surface.

[0011]

[Problems to be solved by the device]

 However, the conventional correction device as described above, before correcting the misconvergence in the peripheral portion of the screen, generates a corner vertical (CV) and an S-shaped curve which occur in the intermediate portion between the central portion and the peripheral portion of the screen. Since both are small, it is not a big problem for the image quality, but when correcting the misconvergence in the peripheral part of the screen, the middle part of the screen is overcorrected and the corner vertical (CV) and S-shaped curves are displayed as shown in FIG. However, there is a problem in that the image quality in the middle part of the screen is significantly deteriorated due to the noticeable blur.

Further, in Japanese Patent Laid-Open No. 62-274537, there is a pair of horizontal deflection coils and a pair of vertical deflection coils, and the horizontal deflection current flowing through the upper horizontal deflection coil and the lower horizontal deflection coil is the vertical deflection current. In a deflection yoke that corrects the lateral convergence by differentially changing by the action of a saturable reactor that is modulated by, a pair of parallel deflection coils windings that control the saturable reactor are connected in series. A deflection yoke having a structure in which parallel diodes with opposite polarities are connected to each other and a resistance is connected in parallel to them is presented. The current waveform flowing in the vertical deflection coil winding is shown in FIG. However, the above problems cannot be solved sufficiently.

Therefore, an object of the present invention is to improve the image quality of the entire screen by compensating for overcorrection of the convergence in the middle part of the screen when correcting the misconvergence in the peripheral part of the screen. To provide.

[0014]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention relates to horizontal auxiliary coils (11a, 11b) (12a, 12b) that are connected in series to horizontal deflection coils 11 and 12 and generate magnetic fields having mutually opposite polarities, and the horizontal auxiliary coils ( 11a, 11b) (12a, 12b) The permanent magnets 13 and 14 that change the inductance of the vertical deflection coils 15 and 16 and the vertical auxiliary coils that are connected in series to correct misconvergence in the periphery of the screen. In the device, the vertical auxiliary coil is divided into a first vertical auxiliary coil 17 and a second vertical auxiliary coil 18, which are connected in series so as to generate magnetic fields having mutually opposite polarities. Is connected in parallel with a slice unit 19 for slicing the vertical deflection current above and below a certain level. To provide a dynamic convergence correction apparatus according to claim.

[0015]

[Action]

 The present invention has two vertical auxiliary coils in which the vertical auxiliary coils are divided into two to generate magnetic fields of opposite polarities, and the slices are connected in parallel to one vertical auxiliary coil and above and below a certain level. A vertical deflection current of a sawtooth wave flows through one vertical auxiliary coil to prevent misconvergence at the periphery of the screen by a convergence correction device that prevents the current from flowing in the vertical auxiliary coil, while other slices are connected in parallel. It compensates for the fact that a sliced vertical deflection current flows through one vertical auxiliary coil and overcorrects the convergence in the middle of the screen, thereby properly correcting the misconvergence over the entire screen and improving the image quality. ..

[0016]

【Example】

 Hereinafter, the correction device of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a circuit diagram showing an embodiment of a deflection yoke according to the correction device of the present invention.

As shown in FIG. 5, two horizontal auxiliary coils (11a, 11b) (12a, 12b) that generate magnetic fields of opposite polarities are connected in series to the horizontal deflection coils 11, 12, respectively. In addition, permanent magnets 13 and 14 for varying the inductances of the horizontal auxiliary coils (11a, 11b) (12a, 12b) are provided, and the vertical deflection coils 15 and 16 are wound in opposite directions to each other and have magnetic fields of opposite polarities. The two vertical auxiliary coils 17 and 18 for generating are connected in series, and the slice portion 19 is connected in parallel to the second vertical auxiliary coil 18.

The slice unit 19 is composed of a pair of diodes 19a and 19b connected in parallel with opposite polarities, and a variable resistor 19c connected in series to the pair of diodes 19a and 19b.

According to the correction device of the present invention configured as described above, as shown in FIG. 6A, the vertical deflection current flowing through the vertical deflection coils 15 and 16 is a sawtooth wave.

Since the first vertical auxiliary coil 17 is connected in series with the vertical deflection coils 15 and 16, the vertical deflection current of the sawtooth wave flowing through the vertical deflection coils 15 and 16 is included in the first vertical auxiliary coil 17. Since the same current flows as in the above, the misconvergence in the peripheral area of the screen is corrected and the three electron beams are concentrated as in the conventional correction device.

Further, a sawtooth vertical deflection current as shown in FIG. 6A also flows through the second vertical auxiliary coil 18, but a pair of diodes 19a, 19a, Vertical deflection currents above and below a certain level are sliced by 19b as shown in FIG. 6 (B).

Further, the second vertical auxiliary coil 18 generates a magnetic field having a polarity opposite to that of the first vertical auxiliary coil 17, so that the convergence in the middle of the screen is opposite to the correction direction of the first vertical auxiliary coil 17. This prevents the middle part of the screen from being over-corrected by correcting the direction, so that the convergence is accurately corrected over the entire screen, corners and S-curves are not generated, and colors are accurately expressed to improve image quality. To be done.

The level for correcting the convergence in the opposite direction is adjusted by changing the value of the variable resistor 19c.

On the other hand, in implementing the present invention, as shown in FIG. 7A, two vertical auxiliary coils 17 and 18 are wound in the same direction, and the other terminal of the first vertical auxiliary coil 17 is connected to the first auxiliary coil 17. The two vertical auxiliary coils 18 may be connected to the other terminal and connected in series so as to generate a magnetic field of opposite polarity.

Further, as shown in FIG. 7B, the diodes 19a and 19b of the slice section 19 and the variable resistor 19c may all be connected in parallel to the second vertical auxiliary coil 18.

[0027]

[Effect of the device]

 As described above, according to the correction device of the present invention, the vertical auxiliary coil is divided into two so as to generate mutually opposite magnetic fields, and a vertical deflection current of a sawtooth wave flows through one vertical auxiliary coil. Corrects the peripheral convergence, and the sliced vertical deflection current flows through the other vertical auxiliary coils in which the slices are connected in parallel.By correcting the overcorrection in the middle of the screen, the misconvergence is corrected over the entire screen. It has an advantage that it can be accurately corrected to achieve improvement in image quality.

Further, according to the correction device of the present invention, the first and second vertical auxiliary coils are configured to generate magnetic fields having polarities opposite to each other. There is an advantage that the correction is performed in the opposite direction to the coil correction direction to prevent the middle part of the screen from being overcorrected.

Further, the variable resistance of the slice part for variably adjusting the level for correcting the convergence in the reverse direction of the correction device of the present invention may be connected in parallel or in series with a pair of diodes connected in antiparallel. Similar effects are obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a deflection yoke in which a conventional convergence correction device is configured.

FIG. 2 is a front view showing a configuration of a conventional convergence correction device.

FIG. 3 is a graph showing the operation of a conventional correction device.

FIG. 4 is a waveform diagram of a current flowing through a vertical deflection coil of another conventional correction device.

FIG. 5 is a circuit diagram of a deflection yoke showing an embodiment of the correction device of the present invention.

FIG. 6 is a waveform diagram showing a vertical deflection current flowing through the correction device of the present invention.

FIG. 7 is a circuit diagram showing another embodiment of the correction device of the present invention.

[Explanation of symbols]

 11, 12 Horizontal deflection coil 11a, 11b, 12a, 12b Horizontal auxiliary coil 13, 14 Permanent magnet 15, 16 Vertical deflection coil 17 First vertical auxiliary coil 18 Second vertical auxiliary coil 19 Slice part 19a, 19b Diode 19c Variable resistance

Claims (5)

[Scope of utility model registration request] 1. Horizontal auxiliary coils (11a, 11b) (12a, 12b) which are connected in series to the horizontal deflection coils 11, 12 and generate magnetic fields of opposite polarities, and the horizontal auxiliary coils (11a, 11b) ( 12a, 12b) permanent magnets 13 and 14 for varying the inductance, and vertical auxiliary coils connected in series to the vertical deflection coils 15 and 16 are used in the dynamic convergence correction device for correcting misconvergence in the peripheral portion of the screen. The auxiliary coil is divided into a first vertical auxiliary coil 17 and a second vertical auxiliary coil 18 that are connected in series so as to generate magnetic fields having opposite polarities, and a vertical deflection current is constant in the second vertical auxiliary coil 18. The dynamic converter is characterized in that slicing units 19 for slicing above and below the level are connected in parallel. Vergence correction device. 2. The first and second vertical auxiliary coils 17, 1
2. The dynamic convergence corrector according to claim 1, wherein 8 are wound in opposite directions so as to generate magnetic fields having polarities opposite to each other. 3. The first and second vertical auxiliary coils 17, 1
8 are wound in the same direction, and the first and second vertical auxiliary coils 17 and 18 are arranged to generate magnetic fields having opposite polarities.
2. The dynamic convergence correction device according to claim 1, wherein the other side terminals of each are connected to each other. 4. The slice section 19 has a pair of diodes 19a, 19b connected in parallel with opposite polarities to each other, and a variable for adjusting a correction level connected in series with the pair of diodes 19a, 19b. 2. The dynamic convergence correction device according to claim 1, comprising a resistor 19c. 5. The slice section 19 has a pair of diodes 19a and 19b connected in parallel with opposite polarities to each other, and a variable level for adjusting a correction level connected in parallel to the pair of diodes 19a and 19b. 2. The dynamic convergence correction device according to claim 1, comprising a resistor 19c.