JPH03150991A - Deflection yoke device with convergence correction circuit and the convergence correction circuit - Google Patents

Abstract

PURPOSE:To obtain a screen of high definition extending over the whole range of a television screen by a executing the correction of a misconvergence by correction current of a parabolic waveform being similar to an ideal waveform. CONSTITUTION:The correction of a half-wave rectification waveform is executed by a first waveform shaping circuit 18a and a second waveform shaping circuit 18b at the time of scanning of the left side half of a television screen, and the time of scanning of the right side half of the screen, respectively, and the generation of an excessive correction state is prevented. That is, parabolic ideal correction current is applied to first correction coils 8a, 8b, and in middle part of the left side half of the television screen, the correction of an under- misconvergence in which an excessive correction is not generated is executed, the correction current of an ideal parabolic waveform is applied to second correction coils 9a, 9b, and in a middle part of the right side half of the television screen, the correction of an under-misconvergence in which an excessive correction is not generated is executed. In such a way, the misconvergence on an X axis of the television screen can be corrected with high accuracy and with high sensitivity.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a deflection yoke device equipped with means for correcting horizontal misconvergence (X)I on the X-axis of the screen of a color cathode ray tube, and its convergence correction circuit. It is related to.

[Conventional technology]

In recent years, cathode ray tube screens (hereinafter referred to as television screens) in color television receivers and color display devices have become increasingly popular.
There is a trend toward higher definition and larger size, and with this, the beam drive becomes wide-angle deflection, and in order to improve focus characteristics, there is a tendency to make the magnetic field distribution of the horizontal deflection coil more linear. However, if the magnetic field distribution of the horizontal deflection coil is made linear, color misalignment between blue B and red R on the , the need to perform this correction is desired.

Further, when designing a color deflection yoke in order to increase the resolution of the screen, the convergence trilemma may be aggregated into misconvergence X11, and in this case as well, it is necessary to correct this aggregated misconvergence x)I.

In order to correct this misconvergence XH,
A blue B electron gun G1, a green G electron gun G,
In a cathode ray tube in which the red R electron gun GR is arranged in-line from left to right when viewed from the screen side, the correction magnetic fields that cross the blue B beam and the red R beam are generated in opposite directions. It is known that a wired four-pole correction coil may be placed in the neck portion of the collar deflection yoke, and a parabolic current synchronized with the horizontal deflection pulse may be caused to flow through the correction coil.

As a circuit for generating this parabolic current, the circuits shown in FIGS. 12 and 13 can be considered. The circuit shown in Fig. 12 connects correction coils 2 and 3 to an inductance connected in series with horizontal deflection coil 1, generates a parabolic current using the resonance of the resonant circuit, and corrects this. This is added as a current to the correction coil 2.3.

In the circuit shown in FIG. 13, four saturable coils 4 are connected to a bridge, and the parabolic current generated by this bridge circuit is applied to the correction coils 2 and 3.

[Problem to be solved by the invention]

However, since the circuit shown in FIG. 12 generates a correction current by resonance, the waveform of the starting current is a waveform between the peaks of the sine waveform as shown by the solid line in FIG. 14. It is a part taken out. As a result, the peak portions P at both ends of the waveform become dull, making it impossible to obtain a current with a sharp rise at both ends as shown by the chain line, resulting in an insufficient amount of correction at the left and right outermost edges of the TV screen, which can lead to accurate errors. There is a problem in that convergence Xll cannot be corrected.

Further, in the circuit shown in FIG. 13, a correction current is generated by a bridge circuit, but this method has a problem in that the correction sensitivity is generally poor. Of course, the sensitivity can be increased by increasing the number of turns of the correction coils 2 and 3, but in this case, the inductance of the correction coils 2 and 3 becomes larger than necessary, and the deflection current flowing through the horizontal deflection coil 1 decreases. A new problem arises in that the deflection amplitude decreases.

The present invention was developed in view of the above circumstances, and its purpose is to provide a deflection yoke with a convergence correction circuit that can correct the misconvergence XN on the X axis of a television screen with high precision and high sensitivity. An object of the present invention is to provide a device and a convergence correction circuit thereof.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention provides a deflection yoke device including a correction coil that receives a correction current and generates a correction magnetic field that vertically alternately crosses blue beams and red beams emitted from an electron gun of a color cathode ray tube; The convergence correction circuit includes a first correction coil that operates when scanning the left half of the screen of the cathode ray tube, and a second correction coil that operates when scanning the right half of the screen of the cathode ray tube. When scanning the left half of the screen, a correction current obtained by half-wave rectification of the horizontal deflection current is used as the first correction current.
a distribution circuit for supplying a correction current to a second correction coil as a correction current obtained by half-wave rectifying the horizontal deflection current when scanning the right half of the screen; and a correction current that is applied to the first correction coil. a first waveform shaping circuit that shapes a half-wave rectified waveform of a correction current into a parabolic shape; and a second waveform shaping circuit that shapes a half-wave rectified waveform of a correction current applied to the second correction coil into a parabolic shape. It is characterized by having the following.

[Effect]

In the present invention, when the deflection yoke is driven, a sawtooth wave horizontal deflection current is applied to the correction current distribution circuit. When scanning the left half of the television screen, this distribution circuit half-wave rectifies the positive side of the horizontal deflection current. This half-wave rectified current is waveform-shaped into a parabolic shape by a first waveform shaping circuit, and this shaped correction current is applied to the first correction coil. The first correction coil receives this correction current,
For example, a first correction magnetic field is generated that vertically alternately crosses a blue B beam and a red R beam emitted from an electron gun of a cathode ray tube. This first correction magnetic field causes misconvergence on the left half of the TV screen.
Corrections are made.

Next, when scanning the right half of the television screen, the horizontal deflection current is distributed and supplied to the second waveform shaping circuit by the correction current distribution circuit. The second waveform shaping circuit shapes the waveform of the right half of the horizontal deflection current into a parabolic shape, and applies this as a correction current to the second correction coil. The second correction coil receives this correction current and generates, for example, a second correction magnetic field in the same direction as the first correction magnetic field generated when scanning the left half of the television screen. Accordingly, the misconvergence XH on the right half of the television screen is corrected.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIGS. 1 and 2 show the main structure of a first embodiment of a deflection yoke device and its convergence correction circuit according to the present invention.

In the device of this embodiment, a correction circuit (convergence correction circuit) 14 for misconvergence Since the configuration of a deflection yoke including a horizontal deflection coil 1 and a vertical deflection coil (not shown) mounted on the bottom side is well known, a description thereof will be omitted.

The misconvergence Xll correction circuit 14 includes a first correction circuit 15 and a second correction circuit 16, and the first correction circuit 15 includes a diode 5, an attenuation resistor 6, and a correction! an adjustment coil 7, first correction coils 8a, 8b,
It consists of a waveform shaping coil 10. The diode 5 includes an attenuation resistor 6, a correction amount adjustment coil 7, and a first correction coil 8a.
, 8b are connected in series, and a waveform shaping coil IO is connected in parallel to this series connection, forming a first correction circuit 15. In this circuit, the attenuation resistor 6 and the waveform shaping coil 10 constitute a first waveform shaping circuit 18a. The input end of the first correction circuit 1.5, that is, the anode side of the diode 5, is connected in series with the horizontal deflection coil 1.

The second correction circuit 16 includes a diode 11.12 and a second
correction coils 9a, 9b, and a second waveform shaping circuit 18b.
It consists of A second correction coil 9a is connected to the diode 12.
, 9b are connected in series, and a diode 11 and a second waveform shaping circuit 18b are each connected in parallel to this series connection to form a second correction circuit 16. The second waveform shaping circuit 18b includes a diode 13, a capacitor 20, and a resistor 21, and a parallel circuit of the capacitor 20 and the resistor 21 is connected to the diode 13.

This second correction circuit 16 is connected in series with the first correction circuit 15. In this connected state, the pair of diodes 5.12 with opposite polarities constitute a correction current distribution circuit.

The first correction coils 8a, 8b and the second correction coil 9
a and 9b are U-shaped cores 2 as shown in FIG.
It is constructed by winding a winding around 2.23, and is placed at the left and right positions of the neck portion 24 of the deflection yoke.

In this embodiment, two windings are wound together around the legs 22a and 22b of the core 22, that is, in a bifilar shape, to constitute a first correction coil 8a and a second correction coil 9a. Similarly, two windings are wound around the legs 23a and 23b of 23 in a bifilar shape to form a first correction coil 8b and a second correction coil 8b.
Each core 22.2 constitutes a correction coil 9b.
3 leg portions 22a, 22b, 23a.

The first correction coil and the second correction coil may be formed by winding the two windings on 23b without overlapping them, that is, by winding them separately from each other and at different locations.

When the first correction coils 8a and 8b are supplied with the correction current shown in FIG. 3(b), the first correction coils 8a and 8b are arranged in a direction from the top side to the bottom side for the blue B beam, as shown in FIG. For the red R beam, the first correction magnetic field B is connected from the bottom side to the top side, and the second correction coil 9a,
9b is when the correction current shown in FIG. 3(C) flows,
As shown by the broken line in FIG. 2, the wires are connected so as to generate a second correction magnetic field B in the same direction as the first correction magnetic field B8. Further, in this embodiment, the first correction coil 8a,
8b and the second correction magnetic field B8 generated from the second correction coil are equal (so that they are symmetrical on the TV screen). Design values such as the number of turns of the correction coil and the second correction coil are associated with each other. The magnitude of the first correction magnetic field B can be adjusted by changing the inductance of the correction amount adjustment coil 7. That is, when the correction elf rectifying coil inductance is increased, the current flowing through the first correction coils 8a, 8b becomes smaller, and the magnitude of the first correction magnetic field B also becomes smaller. On the other hand, if the inductance of the correction amount adjustment coil 7 is made smaller, the current flowing through the coils 8a and 8b becomes larger, and the first correction magnetic field B also becomes larger. The correction amount adjusting coil 7 can be constructed by a coil with a fixed inductance as shown in FIG. 1, but it can also be constructed by a variable inductance.

The present embodiment is configured as described above, and its operation will be explained below.

When the deflection yoke is driven, a sawtooth wave horizontal deflection current as shown in FIG. 4(a) is applied from the horizontal deflection coil 1 to the misconvergence χ□ correction circuit 14. At this time, the diode 5 is turned on when the horizontal deflection pulse shown in FIG. 1st
Utilizing the transient phenomenon of the current flowing through the correction coils 8a and 8b, as shown by the solid line in FIG. Creates a half-wave rectified current of the horizontal deflection current. Also, when scanning the right half of the TV screen, the polarity of the horizontal deflection current is reversed, so diode 5 is turned off and diode 12 is turned on in the forward direction, as shown by the solid line in Figure 4 (C). Then, a half-wave rectified current that has been half-wave rectified by the diode 12 is applied to the second correction coils 9a and 9b.

In this way, when scanning the left half of the television screen, the half-wave rectification effect of the diode 5 and the coil 8a are used.

As shown in FIG.
A first correction magnetic field B is generated from a and 8b that crosses blue B and red R alternately in the upper and lower directions. When scanning the right half of the TV screen, the half-wave rectified current from the diode 12 is applied as a correction current to the second correction coils 9a and 9b, so that the current from the coils 9a and 9b as shown by the broken line in FIG. , a second correction magnetic field Bi is generated in the same direction as when scanning the left half. The blue B and red R beams receive a force in the right direction with respect to the direction in which these correction magnetic fields travel and move in that direction, resulting in under-type misconvergence X1 as shown in Figure 11(b).
1 correction action is performed.

By the way, when fishing on a boat, the horizontal deflection current is used to correct the pattern distortion of the TV screen (for example, the pattern shrinks from the center of the TV screen toward the left and right peripheries) as shown in Fig. 4. As shown in (a), the waveform has undergone three-character correction. Therefore, the half-wave rectified current also has a waveform that is more swollen and rounded than the ideal parabolic waveform shown by the broken line, as shown by the solid line in FIG. 4(b) (C). For this reason, FIG. 4(b).

Misconvergence X11 using the correction current of (C)
When the correction is performed, the bulge part of the half-wave rectified waveform, that is,
As shown in FIG. 5, there is a problem in that the middle portion between the left and right sides of the television screen is overcorrected, and overtype misconvergence XH appears in this middle portion.

In order to solve this problem, in this embodiment, the first waveform shaping circuit 18 is used when scanning the left half of the TV screen, and the second waveform shaping circuit 1 is used when scanning the right half of the screen.
8b corrects the half-wave rectified waveforms, thereby reliably preventing the occurrence of the overcorrection state. That is, when scanning the left half of the television screen, the half-wave rectified current applied from the diode 5 side is applied to the first waveform shaping circuit 18a. In this first waveform shaping circuit 18a, first, by the waveform shaping action of the waveform shaping coil 1O and the damping action of the attenuation resistor 6, a half-wave rectified waveform subjected to 3-character correction is obtained as indicated by the broken line in FIG. 4(b). Shape into a parabolic waveform as shown. In other words, the half-wave rectified waveform is shaped into a suitable waveform by removing the shaded portion. The degree of this parabolic curvature increases as the resistance value of the attenuation resistor 6 increases. Therefore, by variably adjusting the resistance value of the attenuation resistor 6, it is possible to shape the waveform into an ideal parabolic waveform as shown by the broken line. The current shaped into a parabolic shape by the attenuation resistor 6 is subjected to correction ff1il adjustment by the correction amount adjustment coil 7. In other words, correction ff1
If the inductance of the iJ9 adjustment coil 7 is increased, the amount of correction will be decreased, and if the inductance is decreased, the amount of correction will be increased. The current to which the correction ffHJn adjustment coil efcoil correction amount has been adjusted becomes an ideal parabolic correction current as shown in FIG.
.

Next, when scanning the right half of the TV screen, as shown in Fig. 4 (c
) The half-wave rectified current shown by the solid line is the second correction coil 9a,
The current is branched into a current 12 on the 9b side and a current i3 on the second waveform shaping circuit 18b side. The charge of the capacitor 20 of the second waveform shaping circuit 18b is 0 at the start of scanning the right half of the television screen, and the charge of the capacitor 20 increases as the branch current i flows. With this increase in charge, the branch current i on the second waveform shaping circuit 18b side,
gradually decreases, and accordingly, the ratio of the current 12 flowing to the second correction coils 9a, 9b increases.

That is, as the branch current i flows to the second waveform shaping circuit 18b, the shaded part of the half-wave rectified waveform shown by the solid line in FIG. 4(c) becomes the current i3 flowing to the second waveform shaping circuit 18b. A correction current with an ideal parabolic waveform as shown by the broken line, that is, as shown in FIG.
Under misconvergence
It is possible to perform correction of l with high sensitivity and high accuracy. In addition,
In the waveform shaping operation in the second waveform shaping circuit 18b, by adjusting the capacitance of the capacitor 20, it becomes possible to variably adjust the degree of parabolic shape of the correction current.

Next, when the left half of the television screen is scanned, the first waveform shaping circuit 18a operates as described above to perform waveform shaping, but at this time, the second waveform shaping circuit 18b side The charge accumulated in the capacitor 20 is discharged and prepared for the next scan of the right half.

Note that in this embodiment, the first correction coils 8a, 8
If the connection direction of B and the second correction coils 9a and 9b is simultaneously reversed from the above case, the direction of the correction magnetic fields B, , B will be reversed, and the result will be as shown in FIG. 11(a). Correction for overtype misconvergence X11 is performed in the same way.

FIG. 6 shows the main structure of a second embodiment of the present invention. In this second embodiment, the first waveform shaping circuit 18a
The correction amount adjustment coil 7 of the variable inductance correction fi
HJ! The variable resistor 19 is connected in parallel to the series connection body of the diode 12 and the second correction coils 9a and 9b, and the other configuration is the same as the first one. This is similar to the example.

In this second embodiment, the correction amount adjustment coil 7' is made of a variable inductance, and the variable resistor 19 is provided, so that the correction amount of the misconvergence tin can be adjusted. That is, when scanning the left half of the TV screen, if the inductance of the correction amount adjustment coil 7' is increased,
The magnitude of the correction current flowing through the first correction coils 8a, 8b becomes smaller, and the strength of the first correction magnetic field B becomes smaller.

On the other hand, if the inductance of the correction ffi adjustment coil 7' is made smaller, the correction current flowing through the first correction coils 8a, 8b becomes larger, and accordingly, the correction magnetic field B8 generated from the first correction coils 8a, 8b increases. also increases in size. In this way, by adjusting the inductance of the correction amount adjustment coil 7', it is possible to arbitrarily adjust the amount of correction for the misconvergence Xll when scanning the left half of the television screen. When scanning the right half of the TV screen, if the resistance value of the variable resistor 19 is increased,
The magnitude of the correction current flowing through the second correction coils 9a, 9b increases, and the second correction coil 9a.

The magnitude of the second correction magnetic field B emitted from 9b also increases. On the other hand, if the resistance value of the variable resistor 19 is reduced, the magnitude of the correction current flowing through the second correction coils 9a, 9b becomes smaller, and accordingly, the second correction magnetic field B
, also becomes smaller.

In this way, by variably adjusting the resistance value of the variable resistor 19, the amount of correction for misconvergence X when scanning the right half of the television screen can be adjusted as desired.

FIGS. 7 and 8 show the main structure of a third embodiment of the present invention. In this third embodiment, windings are wound around the legs 22a and 22b of the core 22 to form a first correction coil 8.
The second correction coil 9 is formed by winding a winding around the leg portion 23a123b of the core 23, and the other structure is the same as that of the first embodiment. The first correction coil 8 is wired in a direction that generates a correction magnetic field B that directs a blue B beam from the top side to the bottom side when a correction current having a parabolic waveform shown in FIG. 3(b) is applied. , and the second correction coil 9 is similarly connected to the third correction coil 9.
The wires are connected in a direction that generates a correction magnetic field B that crosses the red R beam from the bottom side to the top side when a correction current having a parabolic waveform shown in FIG. 3(C) is applied. As a result, when scanning the left half of the TV screen, the correction current (
A current having the waveform shown in FIG. 3(b) is applied to the first correction coil 8, and the first
Due to the generation of the correction magnetic field B, the blue B beam receives a force to the left toward the television screen and moves in that direction. Further, when scanning the right side of the television screen, a correction current whose waveform is shaped into a parabolic shape by the second waveform shaping circuit 18b (correction current shown in FIG. 3(c)) is applied to the second correction coil 9, Red R from this second correction coil 9
A correction magnetic field B8 is generated that crosses the beam from the bottom side to the top side, and moves the red R beam to the right toward the TV screen to correct the undertype misconvergence Xo as shown in FIG. 11(b). is carried out effectively. When correcting this misconvergence Xo, strictly speaking, when correcting the left half of the TV screen,
The first correction magnetic field B also crosses each of the green G and red R beams from the top side to the bottom side, and has the effect of moving the green G and red R to the left toward the television screen. However, the strength of the magnetic field that crosses blue B. , the strength of the magnetic field that crosses the green G beam is 83G, and the strength of the magnetic field that crosses the red R beam is 8, then the relationship between the respective magnetic field strengths is Bsa>BsG>B
The relationship is □, and the magnitude of the magnetic field B acting on Green G and Red R is sufficiently smaller than the magnitude of the magnetic field acting on Blue B, and the beam of Blue B is smaller than the beam of Green G and Red R. to move relatively to the left.

Similarly, when scanning the right half of the TV screen, the second correction magnetic field BIl crosses the blue B beam and the green G beam from the bottom side to the top side, but the magnetic field that crosses the red R beam The strength becomes sufficiently greater than the strength of the magnetic field crossing each of the blue B and green G beams, and the red R beam moves to the right side relative to the green G and blue B beams. These things,
Undertype misconvergence XH is effectively corrected.

In addition, in this embodiment, if the first correction coil 8 is formed on the core 23 side and the second correction coil 9 is formed on the core 22 side, the first correction coil 8 can be formed when scanning the left half of the television screen. This generates a first correction magnetic field B that crosses the red R beam from the bottom side to the top side, and a second correction magnetic field that crosses the blue B beam from the top side to the bottom side when scanning the right half of the TV screen. B occurs, and similarly, under-type misconvergence XII is effectively corrected. Note that if the connection directions of the first correction coil 8 and the second correction coil 9 are simultaneously reversed from the above case, the direction of the correction magnetic fields B, , B will be reversed, and as shown in FIG. ) Correction of overtype misconvergence X11 as shown in FIG.

The present invention is not limited to the above-described embodiments, and may take various embodiments. For example, in each of the above embodiments, core 22. Although the cores 23 are arranged at the left and right positions of the deflection yoke neck part 24, they may be arranged oppositely above and below the neck part 24 of the deflection yoke, as shown in FIG.

Further, in each of the above embodiments, the first positive coils 8.8a, 8b
and the second correction coils 9, 9a, 9b in the core 22.
Although these are formed on the leg portions 22a, 22b, 23a, and 23b of the core 22.23, they may be formed on the bottom portions 22c and 23c of the core 22.23, as shown in FIG.

Furthermore, in each of the above embodiments, the first correction coil 8.8a
, 8b and the second correction coils 9.9a, 9b are connected to a U-shaped core 22. A four-pole correction magnetic field B alternately crosses the blue B beam and the red R beam in the vertical direction.

Any core shape may be used as long as it is configured to generate BII.

Further, in each of the embodiments described above, the correction current distribution circuit is constructed using the diodes 5 and 12, but it may be constructed using other circuit elements such as transistors.

Furthermore, in each of the first and second embodiments, the first correction coils 8a and 8b are connected in series, and the second
Although the correction coils 9a, 9b are also connected in series, the first correction coil 8a8b and the second correction coil 9a, 9b may be connected in parallel, respectively. Further, the horizontal deflection coils l on the top side and the bottom side may be connected in series.

[Effects of the Invention] The present invention provides separate and independent correction coils for correcting misconvergence XH when scanning the left half of the television screen and when scanning the right half of the television screen.
It becomes possible to control the correction current separately when scanning the left side of the television screen and when scanning the right side of the television screen, making it easier to control the correction of misconvergence XH.

In addition, the correction current applied to the first correction coil and the second
The correction current applied to the correction coil can be shaped into a parabolic waveform by a separate waveform shaping circuit. As a result, misconvergence However, it is possible to provide a high-definition screen with almost no convergence correction deviation (overcorrection) in the middle part of the left half and the middle part of the right half of the TV screen.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the main part configuration of the first embodiment of the present invention, FIG. 2 is a diagram of the arrangement of the correction coil in the same embodiment,
FIG. 3 is an explanatory diagram showing an example of the formation of the correction current in the same embodiment together with the horizontal deflection voltage, FIG. 4 is an explanatory diagram showing the waveform-shaped correction current in the same embodiment together with the horizontal deflection voltage, and FIG. A pattern explanatory diagram showing the state of occurrence of over-correction of misconvergence XH in the left and right intermediate portions of the television screen that occurs when correction is performed using wave rectified current, FIG. 6 is a circuit diagram of the main part of the second embodiment of the present invention, FIG. 7 is a circuit diagram of a main part showing a third embodiment of the present invention, FIG. 8 is a diagram showing how the correction coil is arranged with respect to the deflection yoke in the same embodiment, and FIG. 9 is another arrangement of the correction coil with respect to the deflection yoke. An explanatory diagram showing an example, Fig. 10 is an explanatory diagram showing another example of the winding form of the correction coil, Fig. 11 is a pattern diagram of misconvergence X, 4, and Fig. 11 (a) is an over type misconvergence X). Pattern diagram of I, Figure 11(b)
is a pattern diagram of under-type misconvergence XH, and Figures 12 and 13 are misconvergence X
FIG. 14 is a waveform diagram showing the waveform of the correction current generated by the circuit of FIG. 12 in comparison with the parabolic current waveform. 1...Horizontal deflection coil, 2, 3...Correction coil, 4
... Saturable coil, 5... Diode, 6... Attenuation resistor, 7.7'... Correction ffi adjustment coil, 8.
3a, 8b...first correction coil, 9.9a, 9b...
...Second correction coil, 10...Waveform shaping coil, 1
1.12.13... Diode, 14... Correction circuit, 15... First correction circuit, 16... Second correction circuit, 18a... First waveform shaping circuit, 18b. ...Second waveform shaping circuit, 19...Variable resistor, 20...
Capacitor, 21...Resistor, 22.23...Core, 22a122b, 23a, 23b--Legs, 22c
, 23c - bottom, 24... neck.

Claims (2)

[Claims] (1) A deflection yoke device equipped with a correction coil that receives a correction current and generates a correction magnetic field that alternately crosses blue and red beams emitted from an electron gun of a color cathode ray tube in the vertical direction, The correction coils include a first correction coil that operates when scanning the left half of the screen of the cathode ray tube, and a second correction coil that operates when scanning the right half of the screen.
a correction coil, which supplies a correction current obtained by half-wave rectification of the horizontal deflection current to the first correction coil when scanning the left half of the screen, and half-wave rectification of the horizontal deflection current when scanning the right half of the screen. a first waveform shaping circuit that shapes a half-wave rectified waveform of the correction current applied to the first correction coil into a parabolic shape; A deflection yoke device with a convergence correction circuit, comprising a second waveform shaping circuit that shapes a half-wave rectified waveform of a correction current applied to a second correction coil into a parabolic shape. (2) A first correction coil and a second correction coil that generate correction magnetic fields that vertically alternately cross the blue beam and red beam of the cathode ray tube, and a horizontal deflection current that generates a horizontal deflection current when scanning the left half of the screen. a correction current distribution circuit that supplies a half-wave rectified correction current to a first correction coil, and supplies the horizontal deflection current as a half-wave rectified correction current to a second correction coil when scanning the right half of the screen; a first waveform shaping circuit that shapes a half-wave rectified waveform of the correction current applied to the first correction coil into a parabolic shape; and a first waveform shaping circuit that shapes the half-wave rectified waveform of the correction current applied to the second correction coil into a parabolic shape. A convergence correction circuit for a deflection yoke device, comprising a second waveform shaping circuit.