JP3932696B2 - Horizontal deflection circuit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a horizontal deflection circuit of a television receiver.
[0002]
[Prior art]
For example, Japanese Patent Publication No. 6-38633 has been proposed as a conventional horizontal deflection circuit, and FIG. 5 shows a left and right pincushion distortion correction circuit in the publication.
In FIG. 5, reference numeral 1 denotes a horizontal output transistor. A horizontal drive signal is input to the base of the horizontal output transistor from a horizontal drive circuit, and a power supply voltage is supplied to a collector from a DC power source 2 through a primary winding 3 of a flyback transformer. Is supplied. The emitter is grounded.
A first parallel resonant circuit is configured in which the first damper diode 4 and the first resonant capacitor 6 are connected in parallel, and a second damper diode 5 and the second resonant capacitor 7 are connected in parallel. The first and second parallel resonant circuits are connected in series, and are connected in parallel between the collector and the emitter of the horizontal output transistor 1.
[0003]
Further, between the middle point of the first and second parallel resonant circuits and the collector of the horizontal output transistor 1, the first S-shaped correction capacitor 11, the secondary winding 13b of the correction coil, and the second S-shaped correction capacitor 12 are provided. And the horizontal winding 14 of the deflection coil are connected in series. The secondary winding 13b of the correction coil is transformer-coupled to the correction coil 13a. One of the correction coils 13a is connected to the middle point of the secondary winding 13b of the first S-shaped correction capacitor 11 and the other is grounded. The
Further, a pincushion correction modulation coil 8 is connected to the midpoint between the first and second parallel resonance circuits, and a modulation signal Vm having a vertical period is applied from the modulation source 10. A capacitor 9 is connected between the modulation source 10 and the pincushion correction modulation coil 8, and the other is grounded.
[0004]
In such a deflection circuit, when a downward vertical period parabolic voltage Vm as shown in FIG. 6 is applied from the modulation source 10, a deflection current Iy flows through the horizontal winding 14 of the deflection coil in the direction of the arrow in FIG. A modulation current I ′ by Vm flows through the coil 13a in the direction of the arrow in FIG.
At this time, the horizontal deflection current Iy is modulated with a parabolic voltage corresponding to the difference between the collector voltage Vcp of the horizontal output transistor 1 and the modulation voltage Vm, and the left and right pincushion distortion is corrected. Further, assuming that the inductance of the horizontal winding 14 of the deflection coil is Ly, the inductance of the pincushion correction coil 8 is Lm, the capacitance of the first resonance capacitor 6 is Cf1, and the capacitance of the second resonance capacitor 7 is Cf2, LyCf1 = When the relationship of LmCf2 is established and I ′ does not flow, Vcp is not affected by Vm, and the high voltage output does not vary with Vm.
[0005]
In the horizontal deflection circuit, when the electron beam is scanned, the distance from the deflection center is different between the central portion of the screen and the left and right peripheral portions. Therefore, the horizontal deflection current needs to be S-shaped instead of a linear sawtooth wave.
In addition, the distance from the deflection center is far at the upper and lower ends of the screen and close at the left and right center. For this reason, when the S-curve correction amount is constant, when correction is made so that the pincushion distortion at the left and right ends of the screen is eliminated, the pincushion distortion is overcorrected at the middle part of the screen, and the inner pin distortion as shown in FIG. Arise.
[0006]
In the circuit shown in FIG. 5, in order to solve this problem, the S-shaped correction is performed using the first S-shaped correcting capacitor 11 and the second S-shaped correcting capacitor 12. Since the modulation current I ′ that changes in the vertical period and the horizontal period according to Vm flows through the first S-shaped correction capacitor 11, the S-shaped correction amount changes at the vertical rate according to Vm. Therefore, the S-curve correction amount changes between the center and upper and lower ends of the screen, and the inner pin distortion remaining in the middle portion of the screen is eliminated. In order to increase the correction amount of the inner pin distortion, it is preferable to reduce the capacitance of the first S-shaped correction capacitor 11 without changing the series capacitance of the two S-shaped correction capacitors.
[0007]
That is, since the deflection current Iy and the modulation current I ′ flow in the first S-shaped correction capacitor 11 in opposite directions, the smaller the capacity of the first S-shaped correction capacitor 11 is, The generated S-shaped correction voltage increases.
However, when the deflection current Iy increases, the voltage generated in the first S-shaped correction capacitor 11 becomes too large, and the modulation efficiency due to the modulation voltage Vm decreases. For this reason, the correction coil 13a has a transformer structure, and the deflection current Iy is allowed to flow to the secondary side 13b of the correction coil, thereby reducing the modulation current I ′ and preventing the modulation efficiency from being lowered.
[0008]
[Problems to be solved by the invention]
However, in the conventional configuration, the correction coils 13a and 13b having a transformer structure are necessary to prevent a decrease in modulation efficiency, which increases the cost.
Further, since the current I ′ flows out of the bridge circuit constituted by the two damper diodes, the resonant capacitor, and the modulation source, even when the relationship of LyCf1 = LmCf2 is established, the high-voltage fluctuation and the amplitude fluctuation due to the high-voltage fluctuation occur.
Furthermore, the current I ′ flowing through the correction coil 13a is as shown in FIG. 8, but the point at which this current I ′ is exactly 0 is shifted from the point at which the horizontal deflection current Iy is 0 and shifted by time t, The pincushion correction was also applied to the center, and it was confirmed that the vertical line at the center of the screen was distorted like a bow as shown in FIG.
This phenomenon becomes more conspicuous as the capacitance difference between the first S-shaped correction capacitor 11 and the second S-shaped correction capacitor 12 is larger, and becomes extremely disadvantageous when trying to increase the correction amount of the inner pin distortion.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a normal coil is used in place of the correction coil 13a having a transformer structure, and a circuit structure that does not output current outside the bridge circuit solves high voltage fluctuations and amplitude fluctuations, and also modulates. Prevent efficiency loss.
Also, a correction coil magnetized so that pincushion correction is not applied at the center of the screen is used, and the circuit is configured to control the magnitude of I ′ according to the direction of the current flowing through I ′.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention, first and second parallel circuits and horizontal output transistors in which a damper diode and a resonant capacitor are connected in parallel, first and second S-shaped correction capacitors, and a modulation coil for pincushion correction And the inner pincushion correction coil, the first and second parallel circuits are connected in series and connected between the collector and emitter of the horizontal output transistor, and the pincushion correction modulation coil is the first, It is connected between the midpoint of the second parallel circuit and the modulation source, and the first and second S-shaped correction capacitors and the horizontal winding of the deflection yoke are connected in series. An inner pin correction coil is connected between the collector of the transistor and the midpoint of the first and second parallel circuits, and between the midpoint of the first and second S-shaped correction capacitors and the modulation source. It is the obtained by the horizontal deflection circuit, to reduce costs, eliminate the high pressure fluctuations and arcuate distortion generated at the time of inner pincushion correction.
[0011]
Furthermore, the second invention is the first and second parallel circuit and the horizontal output transistor in which the damper diode and the resonance capacitor are connected in parallel, the first and second S-shaped correction capacitors, the pincushion correction modulation coil, and A magnetized inner pincushion correction coil, wherein the first and second parallel circuits are connected in series and connected between the collector and emitter of the horizontal output transistor, and the pincushion correction modulation coil is The first and second parallel circuits are connected between the midpoint and the modulation source, and the first and second S-shaped correction capacitors and the horizontal winding of the deflection yoke are connected in series. For correcting the inner pin connected between the collector of the horizontal output transistor and the midpoint of the first and second parallel circuits and magnetized between the midpoint of the first and second S-shaped correction capacitors and the modulation source Yl in which has a horizontal deflection circuit coupled to reduce the cost, to eliminate the high-pressure fluctuation and arcuate distortion generated at the time of inner pincushion correction.
[0012]
【Example】
Hereinafter, a horizontal deflection circuit according to an embodiment of the present invention will be described with reference to the drawings.
[0013]
Example 1
FIG. 1 is a circuit diagram of a horizontal deflection circuit according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 is a horizontal output transistor, 2 is a power source, 3 is a primary winding of a flyback transformer, 4 is a first damper diode, 5 is a second damper diode, 6 is a first resonant capacitor, 7 Is a second resonance capacitor, 8 is a modulation coil for pincushion correction, 9 is a capacitor, 10 is a modulation source, 11 is a first S-shaped correction capacitor, 12 is a second S-shaped correction capacitor, and 14 is a deflection coil. A horizontal winding 15 is an inner pin correction coil.
[0014]
The operation of the circuit configuration configured as described above will be described below.
First, a power supply voltage is supplied from a DC power supply 2 through a primary winding 3 of a flyback transformer, and a horizontal cycle drive signal is input from the horizontal drive circuit to the base of the horizontal output transistor 1 to switch the horizontal output transistor 1. Thus, it operates as a horizontal deflection circuit.
Then, when a downward vertical period parabolic voltage Vm as shown in FIG. 6 is applied from the modulation source 10, a deflection current Iy flows through the horizontal winding 14 of the deflection coil in the direction of the arrow in FIG. In FIG. 1, a modulation current I ′ by Vm flows in the direction of the arrow in FIG. At this time, the horizontal deflection current Iy is modulated with a parabolic voltage corresponding to the difference between the collector voltage Vcp of the horizontal output transistor and the modulation voltage Vm, and the left and right pincushion distortion is corrected.
[0015]
The inner pin is corrected using two of the first S-shaped correction capacitor 11 and the second S-shaped correction capacitor 12. Since the modulation current I ′ that changes in the vertical period and the horizontal period according to Vm flows through the first S-shaped correction capacitor 11, the S-shaped correction amount changes at the vertical rate according to Vm. Therefore, the S-curve correction amount changes between the center and upper and lower ends of the screen, and the inner pin distortion remaining in the middle portion of the screen is eliminated.
In order to increase the correction amount of the inner pin distortion, it is preferable to reduce the capacitance of the first S-shaped correction capacitor 11 without changing the series capacitance of the two S-shaped correction capacitors.
Here, since the deflection current Iy and the modulation current I ′ flow through the first S-shaped correction capacitor 11 in opposite directions, the smaller the capacitance of the first S-shaped correction capacitor 11, the more the both ends of the capacitor. The S-shaped correction voltage generated at the time increases.
However, when the deflection current Iy increases, the voltage generated in the first S-shaped correction capacitor 11 becomes too large, and the modulation efficiency due to the modulation voltage Vm decreases.
In the present invention, the inner pin correction coil 15 operates as a part of the pincushion correction modulation coil 8, so that the modulation efficiency does not decrease.
[0016]
Also, since one side of the inner pin correction coil 15 is connected between the pin cushion correction modulation coil 8 and the modulation source 10, the current I ′ is supplied to the first damper diode 4 and the second damper diode 5, Moreover, it does not flow out of the bridge circuit composed of the first resonance capacitor 6 and the second resonance capacitor 7.
Therefore, the equilibrium condition of the bridge circuit is not broken by the current I ′, and the collector voltage Vcp of the horizontal output transistor 1 is not affected by Vm.
That is, the voltage generated at both ends of the primary winding 3 of the flyback transformer is not affected by Vm, and the high-voltage output does not vary with Vm. The conditions under which the high voltage fluctuation and the amplitude fluctuation due to the high voltage fluctuation do not occur are that the inductance of the horizontal winding 14 of the deflection coil is Ly, the parallel inductance of the pincushion correction modulation coil 8 and the inner pin correction coil 15 is Lm ′, It was experimentally confirmed that LyCf1 = Lm′Cf2, where Cf1 is the capacity of the resonant capacitor 6 and Cf2 is the capacity of the second resonant capacitor 7.
(Example 2)
Hereinafter, the horizontal deflection circuit according to the second embodiment of the present invention will be described with reference to FIG. 2, but the description of the same parts as those of the first embodiment will be omitted. FIG. 2 shows a circuit configuration diagram in one embodiment of the present invention.
In FIG. 2, reference numeral 16 denotes a magnetized inner pin correction coil. The difference from the first embodiment is that a magnetized inner pin correction coil 16 is used instead of the inner pin correction coil 15.
In the first embodiment, the waveform of the current I ′ flowing through the inner pin correction coil is determined by the capacitances of the first S-shaped correction capacitor 11 and the second S-shaped correction capacitor 12 and the inductance of the inner pin correction coil 15.
When the inner pin correction amount is small, that is, when the inductance of the inner pin correction coil 15 is large and the capacitance difference between the first S-shaped correction capacitor 11 and the second S-shaped correction capacitor 12 is small, there is no particular problem. When the inner pin correction amount is increased, the waveform of the current I ′ becomes asymmetric between the positive side and the negative side of the current as shown in FIG.
[0017]
At this time, as shown in FIG. 8, the time when the current I ′ becomes 0 and the deflection current Iy are shifted by t, and as a result, the vertical line at the center of the screen is distorted like a bow as shown in FIG.
In the second embodiment, a magnetized inner pin correction coil 16 is used to solve this problem.
An example of the characteristics of the magnetized inner pin correction coil 16 is shown in FIG. As shown in FIG. 3, when a coil having a small inductance when the current passing through the coil is on the negative side, the current increases when the current I 'becomes negative.
That is, since the current value on the + side and the − side of the current I ′ can be controlled by the amount of magnetization of the coil, the time when the current I ′ becomes 0 and the deflection current Iy becomes 0 as shown in FIG. Can be timed.
In this way, pincushion correction is not applied to the center of the screen, and arcuate distortion in the vertical line at the center of the screen can be eliminated.
[0018]
【The invention's effect】
The present invention eliminates the intermediate pincushion distortion and the arcuate distortion in the vertical line at the center of the screen without deteriorating the high voltage fluctuation and amplitude fluctuation characteristics.
Further, pincushion correction can be performed without reducing the modulation efficiency. These are extremely effective for increasing the size and flattening of CRTs.
[Brief description of the drawings]
1 is a circuit diagram of a horizontal deflection circuit according to a first embodiment of the present invention. FIG. 2 is a circuit diagram of a horizontal deflection circuit according to a second embodiment of the present invention. FIG. 3 is a magnetized inner pin in FIG. Fig. 4 is a characteristic diagram of a correction coil. Fig. 4 is a waveform diagram of a current flowing in a magnetized inner pin correction coil in Fig. 2. Fig. 5 is a circuit diagram of a conventional horizontal deflection circuit. Waveform diagram [Fig. 7] Diagram showing conventional inner pin distortion [Fig. 8] Waveform diagram showing current flowing in the conventional circuit [Fig. 9] Diagram showing conventional bow distortion at the center vertical line of the screen [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Horizontal output transistor 2 DC power supply 3 Primary winding 4 of a flyback transformer 1st damper diode 5 2nd damper diode 6 1st resonance capacitor 7 2nd resonance capacitor 8 Pin cushion correction modulation coil 9 Capacitor 10 Modulation Source 11 First S-Correcting Capacitor 12 Second S-Correcting Capacitor 13a Correction Coil 13b Secondary Side of Correction Coil 14 Horizontal Winding of Deflection Coil 15 Inner Pin Correction Coil 16 Inner Pin Correction Magnetization Coil

Claims (2)

1st and 2nd parallel circuit and horizontal output transistor with damper diode and resonant capacitor connected in parallel, 1st and 2nd S-shaped correction capacitor, modulation coil for pincushion correction and coil for inner pincushion correction The first and second parallel circuits are connected in series and connected between the collector and emitter of the horizontal output transistor, and the pincushion correction modulation coil is connected to the midpoint of the first and second parallel circuits. The first and second S-shaped correction capacitors and the horizontal winding of the deflection yoke are connected in series, and this series circuit is connected between the collector of the horizontal output transistor and the first and second. A horizontal deflection circuit in which an inner pin correction coil is connected between the midpoint of the first and second S-shaped correction capacitors and the modulation source. First and second parallel circuits and horizontal output transistors in which a damper diode and a resonant capacitor are connected in parallel, first and second S-shaped correction capacitors, a pincushion correction modulation coil, and a magnetized inner pincushion correction The first and second parallel circuits are connected in series and connected between the collector and emitter of the horizontal output transistor, and the pincushion correction modulation coil is connected to the first and second parallel circuits. The first and second S-shaped correction capacitors and the horizontal winding of the deflection yoke are connected in series, and the series circuit is connected between the collector of the horizontal output transistor and the first output. Horizontally connected to the midpoint of the second parallel circuit and connected to the inner pin correction coil magnetized between the midpoint of the first and second S-shaped correction capacitors and the modulation source Direction circuit.

Images