JPH05176193A - Horizontal deflection distortion correction device - Google Patents

Abstract

PURPOSE:To correct a deflection distortion caused by a waveform distortion of a horizontal deflection current without increasing the waveform distortion of a horizontal deflection current by applying a deflection correction voltage obtained based on a horizontal output voltage to a sub horizontal deflection coil. CONSTITUTION:A horizontal output voltage extracted from an output transformer 14 in a horizontal deflection output circuit 10 to supply a horizontal deflection current Im to a main horizontal deflection coil 16 of a picture tube 18 is fed to an integration operation section comprising the series connection between a resistive element 21 and a capacitive element 2. Thus, a deflection correction voltage Vc obtained based on the horizontal output voltage is fed to a sub horizontal deflection coil 24 and a deflection correction circumferential Ic is supplied thereto. As a result, the deflection distortion caused by the waveform distortion of the horizontal deflection current Im is corrected by the deflection by the sub horizontal deflection coil 24. Thus, the deflection by the sub horizontal deflection coil 24 is corrected without increasing a waveform distortion of the horizontal deflection current Im.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal deflection distortion correction device for correcting horizontal deflection distortion generated in a picture tube in which an electron beam whose intensity is modulated based on a video signal is horizontally and vertically deflected.

[0002]

2. Description of the Related Art In a picture tube (image display cathode ray tube) used in a television receiver or an image monitor device, an electron beam whose intensity is modulated by a video signal supplied thereto is horizontally deflected inside. At the same time, horizontal and vertical scanning is performed on the phosphor layer vertically deflected and arranged on the image display surface portion, and as a result, a reproduced image based on the video signal is obtained on the image display surface portion. The horizontal and vertical deflections of the electron beam performed in the picture tube in such a case are usually formed in the picture tube by the horizontal and vertical deflection coils arranged on the outer periphery of the joint portion between the neck portion and the funnel portion of the picture tube. Is performed by the horizontal and vertical deflection magnetic fields.

When the horizontal and vertical deflection coils form a horizontal deflection magnetic field and a vertical deflection magnetic field in the picture tube, the horizontal deflection current and the vertical deflection current, which basically form a sawtooth waveform, are applied to the horizontal deflection coil and the vertical deflection coil. Each is supplied. The horizontal deflection current flowing through the horizontal deflection coil has a frequency of, for example, about 15.75 kHz, and the vertical deflection current flowing through the vertical deflection coil has a frequency lower than that of the horizontal deflection current. For example, it is set to about 60 Hz.

[0004]

As described above, the horizontal deflection current flowing through the horizontal deflection coil arranged in the picture tube basically has, for example, a frequency of 15.7.
A sawtooth waveform having a frequency of 5 kHz is formed, but the portion that should have a linearly increasing change or a linearly decreasing change in the sawtooth waveform due to the effect of the resistance component of the horizontal deflection coil itself is an exponential function. Waveform change occurs, which causes waveform distortion. The time constant at that time is Ld, where Ld is the value of the inductance component of the horizontal deflection coil and Rd is the value of the resistance component of the horizontal deflection coil.
/ Rd In this way, when the horizontal deflection current flowing through the horizontal deflection coil is caused to have waveform distortion, the reproduced image obtained on the image display surface portion of the picture tube is changed in the horizontal direction on the image display surface portion. That is, the deflection distortion is gradually generated from one side portion to the other side portion.

Therefore, in order to correct the waveform distortion of the horizontal deflection current flowing through the horizontal deflection coil arranged in the picture tube, for example, as disclosed in Japanese Patent Publication No. Sho 63-5951. In addition to the horizontal deflection coil arranged in the tube, an auxiliary horizontal deflection coil is provided, and a resistance element for voltage detection is connected in series to the horizontal deflection coil,
A voltage proportional to the horizontal deflection current flowing through the horizontal deflection coil, which is obtained between both ends of the voltage detection resistance element, is applied to the auxiliary horizontal deflection coil to supply the deflection correction current to the auxiliary horizontal deflection coil, and It has been proposed to correct the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the horizontal deflection coil by the deflection by the auxiliary horizontal deflection coil.

However, when the horizontal deflection distortion is corrected by using such a voltage detecting resistance element connected in series to the horizontal deflection coil, the voltage connected in series to the horizontal deflection coil. The resistance element for detection, together with the resistance component of the horizontal deflection coil itself, causes waveform distortion in the horizontal deflection current that is supposed to flow through the horizontal deflection coil, and accordingly, is caused to flow through the horizontal deflection coil. The degree of waveform distortion in the horizontal deflection current is increased. As a result, the amount of deflection correction by the auxiliary horizontal deflection coil for the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the horizontal deflection coil is increased, and proper and sufficient correction cannot be performed. There is a risk that it will end up.

In view of such a point, in the present invention, in addition to the horizontal deflection coil arranged in the picture tube, an auxiliary horizontal deflection coil is provided, a deflection correction current is supplied to the auxiliary horizontal deflection coil, and the horizontal deflection coil flows through the horizontal deflection coil. When the deflection distortion caused by the waveform distortion of the deflection current is corrected by the deflection by the auxiliary horizontal deflection coil, it is possible to avoid the situation that the waveform distortion of the horizontal deflection current flowing through the horizontal deflection coil is increased. It is an object of the present invention to provide a horizontal deflection distortion correction device.

[0008]

In order to achieve the above-mentioned object, a horizontal deflection distortion correcting apparatus according to the present invention is a main horizontal deflection coil provided in a picture tube for horizontal and vertical scanning of an electron beam. And a sub-horizontal deflection coil provided separately from the sub-horizontal deflection coil, and a voltage extraction unit for extracting a horizontal output voltage from an output transformer in a horizontal deflection output circuit for supplying a horizontal deflection current to the main horizontal deflection coil, and a voltage extraction unit. An integration operation section including a series connection of a resistance element and a capacitance element to which a horizontal output voltage is supplied, and a deflection correction voltage obtained by the integration operation section based on the horizontal output voltage is applied to the sub-horizontal deflection coil, A correction current supply unit that supplies a deflection correction current to the sub-horizontal deflection coil is provided and configured.

Further, in an example of the horizontal deflection distortion correction device according to the present invention, the time constant defined by the resistance component and the capacitance component in the integral operation section is equal to the resistance component in the main horizontal deflection coil. It is selected to be substantially equal to the time constant defined by the inductance component.

[0010]

In the horizontal deflection distortion correction apparatus according to the present invention constructed as described above, the horizontal output voltage extracted from the output transformer in the horizontal deflection output circuit for supplying the horizontal deflection current to the main horizontal deflection coil is the resistance. A deflection correction voltage, which is supplied to an integrating operation unit including a series connection of an element and a capacitance element, and which is obtained based on the horizontal output voltage, is applied to the sub-horizontal deflection coil, thereby deflecting the sub-horizontal deflection coil. Correction current is supplied,
As a result, the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil is corrected by the deflection by the sub horizontal deflection coil. Therefore, the correction of the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil by the deflection by the sub horizontal deflection coil does not increase the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil. Therefore, it is performed without increasing the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil.

Further, in an example of the horizontal deflection distortion correction device according to the present invention, the time constant defined by the resistance component and the capacitance component in the integral operation section for obtaining the deflection correction voltage based on the horizontal output voltage is the main horizontal A sub-horizontal deflection for deflection distortion due to waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil is selected, which is substantially equal to the time constant defined by the resistance component and the inductance component in the deflection coil. The correction by the deflection by the coil is performed in a state in which the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil is removed substantially without excess or deficiency.

[0012]

1 shows an example of a horizontal deflection distortion correction device according to the present invention, together with a horizontal deflection output circuit, a picture tube and the like to which it is applied. The horizontal deflection output circuit, the picture tube, and the like shown in FIG. 1 are used in a television receiver.

In FIG. 1, a horizontal deflection output circuit 10 is provided.
However, a switching transistor 11 having a drive signal input terminal 11A provided at the base and an emitter grounded,
The damper diode 12 and the capacitance element 13 connected in parallel between the collector of the switching transistor 11 and the ground potential point, and one end of the output transformer 14 is connected to the collector of the switching transistor 11 and the other end is connected to the power supply 15. And a primary winding 14P. Then, one end of the main horizontal deflection coil 16 attached to the picture tube 18 is connected to the connection point between the collector of the switching transistor 11 and the primary winding 14P of the output transformer 14, and the other end of the horizontal deflection coil 16 is It is grounded via a capacitance element 17 for S-shaped correction.

A sub-horizontal deflection coil 24 is attached to the picture tube 18 separately from the main horizontal deflection coil 16 attached thereto. The resistance element 21 and the capacitance element 22 are connected in series between the other end of the secondary winding 14S whose one end is grounded and the ground potential point in the output transformer 14 provided in the horizontal deflection output circuit 10. ing. Further, the resistance element 21 and the capacitance element 2
A connection point Q between the auxiliary horizontal deflection coil 24 and the second horizontal deflection coil 24 is connected to one end of the sub horizontal deflection coil 24 through a voltage follower 23, and the other end of the sub horizontal deflection coil 24 is grounded. Under such a configuration, the horizontal deflection distortion according to the present invention is controlled by the sub-horizontal deflection coil 24, the secondary winding 14S of the output transformer 14, the series connection of the resistance element 21 and the capacitance element 22, and the voltage follower 23. An example of the correction device is configured, and the series connection of the resistance element 21 and the capacitance element 22 forms an incomplete integration circuit, and the resistance component R and the capacitance component C in the incomplete integration circuit are used. The specified time constant C ・ R is
It is selected to be substantially equal to the time constant Ld / Rd defined by the resistance component Rd and the inductance component Ld in the main horizontal deflection coil 16.

Under such a condition, the drive signal input terminal 11
A is supplied with a horizontal drive signal Sd having a high level for a predetermined period with a horizontal period Th as shown in A of FIG. 2, whereby the switching transistor 1 is supplied.
1 is turned on for each high level portion of the horizontal drive signal Sd. As a result, the horizontal output voltage V as shown in B of FIG. 2 is applied to the primary winding 14P of the output transformer 14.
h is obtained, and based on that, the main horizontal deflection coil 16
Then, a horizontal deflection current Im as shown by C in FIG. 2 is supplied. The horizontal deflection current Im is basically a sawtooth wave current having a horizontal period Th, but the portion that should originally increase linearly has a gentle S-shape due to the action of the S-correction capacitance element 17. And an index with a time constant Ld / Rd defined by the resistance component Rd and the inductance component Ld in the main horizontal deflection coil 16 under the influence of the resistance component Rd in the main horizontal deflection coil 16 itself. It is considered that waveform distortion that causes a functional change is generated.

Therefore, if the horizontal deflection of the electron beam in the picture tube 18 is performed only by the horizontal deflection magnetic field formed by the horizontal deflection current Im flowing through the main horizontal deflection coil 16, the electron beam is deflected. The horizontal deflection becomes a deflection distortion corresponding to the waveform distortion of the horizontal deflection current Im, and the image reproduced on the image display surface portion of the picture tube 18 ends the horizontal scanning from the starting end side of the horizontal scanning in the horizontal direction. The resulting image distortion gradually becomes closer to the edge side.

In the example shown in FIG. 1, in such a case,
The secondary winding 14S of the output transformer 14 is shown in FIG.
The horizontal output voltage Vh shown in B has the same polarity,
And, in the state where the level is reduced, it is taken out as a voltage Vh 'as shown by D in FIG. Then, the voltage Vh ′ obtained on the secondary winding 14S of the output transformer 14 is supplied to the series connection of the resistance element 21 and the capacitance element 22 which form an incomplete integration circuit, and the resistance element 21 and the capacitance element 22. Connection point Q between
In addition, the voltage Vh ′ is equal to the resistance element 21 and the capacitance element 2
The deflection correction voltage Vc as shown by E in FIG.

This deflection correction voltage Vc is substantially due to the imperfect integration circuit formed by the series connection of the resistance element 21 and the capacitance element 22 with the level of the horizontal output voltage Vh reduced. It is formed by integration, and therefore basically the horizontal period T
A sawtooth voltage having h, but a time constant C · R defined by a resistance component R and a capacitance component C in the series connection of the resistance element 21 and the capacitance element 22.
It is assumed that the waveform distortion that changes exponentially with is generated, and the resistance element 21 and the capacitance element 22
The time constant C · R defined by the resistance component R and the capacitance component C in the series connection with the resistance component Rd and the inductance component Ld in the main horizontal deflection coil 16 are
Since it is selected to be substantially equal to the time constant Ld / Rd defined by, the main horizontal deflection coil 16
It has a waveform proportional to the horizontal deflection current Im flowing through.

In this way, the deflection correction voltage Vc obtained at the connection point Q between the resistance element 21 and the capacitance element 22 is supplied to the sub-horizontal deflection coil 24 through the voltage follower 23, whereby the sub-horizontal deflection coil 24 is supplied. The deflection coil 24 is supplied with a deflection correction current Ic based on the deflection correction voltage Vc as shown by F in FIG. As the deflection correction current Ic, a deflection correction voltage Vc having a waveform proportional to the horizontal deflection current Im flowing through the main horizontal deflection coil 16 (a waveform similar to the waveform of the horizontal deflection current Im) is supplied to the sub horizontal deflection coil 24. Accordingly, the auxiliary horizontal deflection coil 24 is caused to flow, and therefore, the reason as described in the above-mentioned Japanese Patent Publication No. 63-5951 (current im in Japanese Patent Publication No. 63-5951 and Current is
(Corresponding to the horizontal deflection current Im and the deflection correction current Ic, respectively), as shown in G of FIG.
The current Iz, which is the sum of m and the deflection correction current Ic, becomes a sawtooth wave current having a horizontal period with substantially no waveform distortion.

As described above, the sum of the horizontal deflection current Im flowing through the main horizontal deflection coil 16 and the deflection correction current Ic flowing through the sub horizontal deflection coil 24, the current Iz, is substantially free from waveform distortion. A state in which a saw-tooth wave current having a horizontal period has a relationship that is equivalent to the main horizontal deflection coil 16 provided only in the main horizontal deflection coil 16 without providing the sub horizontal deflection coil 24 in the picture tube 18. A current Iz, which is a saw-tooth wave current having a horizontal period and having substantially no waveform distortion, is supplied to the deflection coil 16 as if it were supplied as a horizontal deflection current. The horizontal deflection of is not accompanied by deflection distortion.

That is, in the example shown in FIG. 1, the deflection distortion of the horizontal deflection of the electron beam in the picture tube 18 caused by the waveform distortion of the horizontal deflection current Im flowing through the main horizontal deflection coil 16 is shown. The deflection correction current Ic is supplied to the sub-horizontal deflection coil 24 to correct the horizontal deflection action on the electron beam in the picture tube 18, and the picture tube 18 is corrected.
The horizontal deflection of the electron beam inside is essentially free of deflection distortion.

In the example shown in FIG. 1, the time constant C · R defined by the resistance component R and the capacitance component C in the series connection of the resistance element 21 and the capacitance element 22 is the main horizontal deflection. The coil 16 is selected so as to be substantially equal to the time constant Ld / Rd defined by the resistance component Rd and the inductance component Ld. However, in the horizontal deflection distortion correction device according to the present invention, this is the case. The condition is not always necessary, and the resistance element 21
The time constant C · R defined by the resistance component R and the capacitance component C in the serial connection of the capacitance element 22 and the capacitance element 22 is the resistance component Rd in the main horizontal deflection coil 16.
And the time constant L defined by the inductance component Ld
Regarding the horizontal deflection of the electron beam in the picture tube 18 caused by the waveform distortion of the horizontal deflection current Im flowing through the main horizontal deflection coil 16 unless it is selected to be substantially equal to d / Rd. The deflection distortion is not corrected by the horizontal deflection action on the electron beam in the picture tube 18 by supplying the deflection correction current Ic to the sub-horizontal deflection coil 24, but is not practically corrected. A correction will be made that results in a reduction in which the effect is clearly recognized.

Further, in the example shown in FIG. 1, the power supply 15 in the horizontal deflection output circuit 10 is supposed to supply a constant power supply voltage. , Power supply 1 in horizontal deflection output circuit 10
5 can also be applied in the same manner as described above, even when the power supply voltage that fluctuates in a predetermined cycle is supplied in order to reduce the pincushion distortion of the reproduced image in the picture tube 18.

[0024]

As is apparent from the above description, in the horizontal deflection distortion correction apparatus according to the present invention, the horizontal deflection output circuit in the horizontal deflection output circuit for supplying the horizontal deflection current to the main horizontal deflection coil is driven by the horizontal transformer. The output voltage is
The deflection correction voltage obtained based on the horizontal output voltage is applied to the sub-horizontal deflection coil by being supplied to the integration operation unit including the series connection of the resistance element and the capacitance element, and thus the sub-horizontal deflection coil is applied to the sub-horizontal deflection coil. The deflection correction current is supplied, and as a result, the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil is corrected by the deflection by the sub horizontal deflection coil.
The deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil is corrected by the deflection by the sub-horizontal deflection coil without increasing the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil. This can be performed without increasing the deflection distortion caused by the waveform distortion of the horizontal deflection current flowing through the main horizontal deflection coil.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an example of a horizontal deflection distortion correction device according to the present invention, together with a horizontal deflection output circuit, a picture tube, and the like to which it is applied.

FIG. 2 is a waveform diagram provided for explaining the operation of the example shown in FIG.

[Explanation of symbols]

 10 horizontal deflection output circuit 11 switching transistor 12 damper diode 14 output transformer 14P primary winding 14S secondary winding 15 power supply 16 main horizontal deflection coil 18 picture tube 21 resistance element 22 capacitance element 23 voltage follower 24 sub-horizontal deflection coil

Claims (2)

[Claims] 1. A sub-horizontal deflection coil, which is provided separately from a main horizontal deflection coil provided in the picture tube, in a picture tube in which horizontal and vertical scanning of an electron beam is performed, and the sub-horizontal deflection coil is horizontally provided in the main horizontal deflection coil. The horizontal deflection output circuit for supplying the deflection current includes a voltage extraction unit for extracting a horizontal output voltage from the output transformer, and a series connection of a resistance element and a capacitance element to which the horizontal output voltage obtained from the voltage extraction unit is supplied. An integration operation section, and a correction current supply section that applies a deflection correction voltage obtained based on the horizontal output voltage by the integration operation section to the sub-horizontal deflection coil to supply a deflection correction current to the sub-horizontal deflection coil. A horizontal deflection distortion correction device comprising: 2. A time constant defined by a resistance component and a capacitance component in the integral operation section is selected to be substantially equal to a time constant defined by a resistance component and an inductance component in the main horizontal deflection coil. The horizontal deflection distortion correction device according to claim 1, characterized in that.